首页 > 编程语言 >关于java中Excel的导入导出

关于java中Excel的导入导出

时间:2024-08-27 11:07:17浏览次数:10  
标签:return String int Excel private 导入 static new java

前言
提示:注意看文字的提醒:

例如:
提示: 就这几个表别搞乱了就行其实很简单
ExcelClassField ------ Excel标题栏工具类–不用管
ExcelExport------导出配置工具类—用于对象表的配置上
ExcelImport----导入配置工具类—用于对象表的配置上
ExcelUtils-----用于接口调用上
 

一、配置pom依赖

<!-- 文件上传 -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>4.5.7</version>
        </dependency>
        <!-- JSON -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.41</version>
        </dependency>
        <!-- POI -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.16</version>
        </dependency>

二、搭建utils工具类

1.Excel表头设置表

代码如下(示例):基本上不用动

package com.information.utils;

import java.util.LinkedHashMap;

/** Excel 表头设置
 */
public class ExcelClassField {

    /** 字段名称 */
    private String fieldName;

    /** 表头名称 */
    private String name;

    /** 映射关系 */
    private LinkedHashMap<String, String> kvMap;

    /** 示例值 */
    private Object example;

    /** 排序 */
    private int sort;

    /** 是否为注解字段:0-否,1-是 */
    private int hasAnnotation;

    public String getFieldName() {
        return fieldName;
    }

    public void setFieldName(String fieldName) {
        this.fieldName = fieldName;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public LinkedHashMap<String, String> getKvMap() {
        return kvMap;
    }

    public void setKvMap(LinkedHashMap<String, String> kvMap) {
        this.kvMap = kvMap;
    }

    public Object getExample() {
        return example;
    }

    public void setExample(Object example) {
        this.example = example;
    }

    public int getSort() {
        return sort;
    }

    public void setSort(int sort) {
        this.sort = sort;
    }

    public int getHasAnnotation() {
        return hasAnnotation;
    }

    public void setHasAnnotation(int hasAnnotation) {
        this.hasAnnotation = hasAnnotation;
    }

}

2.Excel导入导出工具类

代码如下(示例):

package com.information.utils;


import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.apache.poi.hssf.usermodel.HSSFDataValidation;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.ClientAnchor.AnchorType;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.ss.util.CellRangeAddressList;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFClientAnchor;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.net.URL;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.Map.Entry;
import java.util.regex.Pattern;

/**
 * Excel导入导出工具类
 */
@SuppressWarnings("unused")
public class ExcelUtils {

    private static final String XLSX = ".xlsx";
    private static final String XLS = ".xls";
    public static final String ROW_MERGE = "row_merge";
    public static final String COLUMN_MERGE = "column_merge";
    private static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
    private static final String ROW_NUM = "rowNum";
    private static final String ROW_DATA = "rowData";
    private static final String ROW_TIPS = "rowTips";
    private static final int CELL_OTHER = 0;
    private static final int CELL_ROW_MERGE = 1;
    private static final int CELL_COLUMN_MERGE = 2;
    private static final int IMG_HEIGHT = 30;
    private static final int IMG_WIDTH = 30;
    private static final char LEAN_LINE = '/';
    private static final int BYTES_DEFAULT_LENGTH = 10240;
    private static final NumberFormat NUMBER_FORMAT = NumberFormat.getNumberInstance();


    public static <T> List<T> readFile(File file, Class<T> clazz) throws Exception {
        JSONArray array = readFile(file);
        return getBeanList(array, clazz);
    }

    public static <T> List<T> readMultipartFile(MultipartFile mFile, Class<T> clazz) throws Exception {
        JSONArray array = readMultipartFile(mFile);
        return getBeanList(array, clazz);
    }

    public static JSONArray readFile(File file) throws Exception {
        return readExcel(null, file);
    }

    public static JSONArray readMultipartFile(MultipartFile mFile) throws Exception {
        return readExcel(mFile, null);
    }

    public static Map<String, JSONArray> readFileManySheet(File file) throws Exception {
        return readExcelManySheet(null, file);
    }

    public static Map<String, JSONArray> readFileManySheet(MultipartFile file) throws Exception {
        return readExcelManySheet(file, null);
    }

    private static <T> List<T> getBeanList(JSONArray array, Class<T> clazz) throws Exception {
        List<T> list = new ArrayList<>();
        Map<Integer, String> uniqueMap = new HashMap<>(16);
        for (int i = 0; i < array.size(); i++) {
            list.add(getBean(clazz, array.getJSONObject(i), uniqueMap));
        }
        return list;
    }

    /**
     * 获取每个对象的数据
     */
    private static <T> T getBean(Class<T> c, JSONObject obj, Map<Integer, String> uniqueMap) throws Exception {
        T t = c.newInstance();
        Field[] fields = c.getDeclaredFields();
        List<String> errMsgList = new ArrayList<>();
        boolean hasRowTipsField = false;
        StringBuilder uniqueBuilder = new StringBuilder();
        int rowNum = 0;
        for (Field field : fields) {
            // 行号
            if (field.getName().equals(ROW_NUM)) {
                rowNum = obj.getInteger(ROW_NUM);
                field.setAccessible(true);
                field.set(t, rowNum);
                continue;
            }
            // 是否需要设置异常信息
            if (field.getName().equals(ROW_TIPS)) {
                hasRowTipsField = true;
                continue;
            }
            // 原始数据
            if (field.getName().equals(ROW_DATA)) {
                field.setAccessible(true);
                field.set(t, obj.toString());
                continue;
            }
            // 设置对应属性值
            setFieldValue(t, field, obj, uniqueBuilder, errMsgList);
        }
        // 数据唯一性校验
        if (uniqueBuilder.length() > 0) {
            if (uniqueMap.containsValue(uniqueBuilder.toString())) {
                Set<Integer> rowNumKeys = uniqueMap.keySet();
                for (Integer num : rowNumKeys) {
                    if (uniqueMap.get(num).equals(uniqueBuilder.toString())) {
                        errMsgList.add(String.format("数据唯一性校验失败,(%s)与第%s行重复)", uniqueBuilder, num));
                    }
                }
            } else {
                uniqueMap.put(rowNum, uniqueBuilder.toString());
            }
        }
        // 失败处理
        if (errMsgList.isEmpty() && !hasRowTipsField) {
            return t;
        }
        StringBuilder sb = new StringBuilder();
        int size = errMsgList.size();
        for (int i = 0; i < size; i++) {
            if (i == size - 1) {
                sb.append(errMsgList.get(i));
            } else {
                sb.append(errMsgList.get(i)).append(";");
            }
        }
        // 设置错误信息
        for (Field field : fields) {
            if (field.getName().equals(ROW_TIPS)) {
                field.setAccessible(true);
                field.set(t, sb.toString());
            }
        }
        return t;
    }

    private static <T> void setFieldValue(T t, Field field, JSONObject obj, StringBuilder uniqueBuilder, List<String> errMsgList) {
        // 获取 ExcelImport 注解属性
        ExcelImport annotation = field.getAnnotation(ExcelImport.class);
        if (annotation == null) {
            return;
        }
        String cname = annotation.value();
        if (cname.trim().length() == 0) {
            return;
        }
        // 获取具体值
        String val = null;
        if (obj.containsKey(cname)) {
            val = getString(obj.getString(cname));
        }
        if (val == null) {
            return;
        }
        field.setAccessible(true);
        // 判断是否必填
        boolean require = annotation.required();
        if (require && val.isEmpty()) {
            errMsgList.add(String.format("[%s]不能为空", cname));
            return;
        }
        // 数据唯一性获取
        boolean unique = annotation.unique();
        if (unique) {
            if (uniqueBuilder.length() > 0) {
                uniqueBuilder.append("--").append(val);
            } else {
                uniqueBuilder.append(val);
            }
        }
        // 判断是否超过最大长度
        int maxLength = annotation.maxLength();
        if (maxLength > 0 && val.length() > maxLength) {
            errMsgList.add(String.format("[%s]长度不能超过%s个字符(当前%s个字符)", cname, maxLength, val.length()));
        }
        // 判断当前属性是否有映射关系
        LinkedHashMap<String, String> kvMap = getKvMap(annotation.kv());
        if (!kvMap.isEmpty()) {
            boolean isMatch = false;
            for (String key : kvMap.keySet()) {
                if (kvMap.get(key).equals(val)) {
                    val = key;
                    isMatch = true;
                    break;
                }
            }
            if (!isMatch) {
                errMsgList.add(String.format("[%s]的值不正确(当前值为%s)", cname, val));
                return;
            }
        }
        // 其余情况根据类型赋值
        String fieldClassName = field.getType().getSimpleName();
        try {
            if ("String".equalsIgnoreCase(fieldClassName)) {
                field.set(t, val);
            } else if ("boolean".equalsIgnoreCase(fieldClassName)) {
                field.set(t, Boolean.valueOf(val));
            } else if ("int".equalsIgnoreCase(fieldClassName) || "Integer".equals(fieldClassName)) {
                try {
                    field.set(t, Integer.valueOf(val));
                } catch (NumberFormatException e) {
                    errMsgList.add(String.format("[%s]的值格式不正确(当前值为%s)", cname, val));
                }
            } else if ("double".equalsIgnoreCase(fieldClassName)) {
                field.set(t, Double.valueOf(val));
            } else if ("long".equalsIgnoreCase(fieldClassName)) {
                field.set(t, Long.valueOf(val));
            } else if ("BigDecimal".equalsIgnoreCase(fieldClassName)) {
                field.set(t, new BigDecimal(val));
            } else if ("Date".equalsIgnoreCase(fieldClassName)) {
                try {
                    field.set(t, new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(val));
                } catch (Exception e) {
                    field.set(t, new SimpleDateFormat("yyyy-MM-dd").parse(val));
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static Map<String, JSONArray> readExcelManySheet(MultipartFile mFile, File file) throws IOException {
        Workbook book = getWorkbook(mFile, file);
        if (book == null) {
            return Collections.emptyMap();
        }
        Map<String, JSONArray> map = new LinkedHashMap<>();
        for (int i = 0; i < book.getNumberOfSheets(); i++) {
            Sheet sheet = book.getSheetAt(i);
            JSONArray arr = readSheet(sheet);
            map.put(sheet.getSheetName(), arr);
        }
        book.close();
        return map;
    }

    private static JSONArray readExcel(MultipartFile mFile, File file) throws IOException {
        Workbook book = getWorkbook(mFile, file);
        if (book == null) {
            return new JSONArray();
        }
        JSONArray array = readSheet(book.getSheetAt(0));
        book.close();
        return array;
    }

    private static Workbook getWorkbook(MultipartFile mFile, File file) throws IOException {
        boolean fileNotExist = (file == null || !file.exists());
        if (mFile == null && fileNotExist) {
            return null;
        }
        // 解析表格数据
        InputStream in;
        String fileName;
        if (mFile != null) {
            // 上传文件解析
            in = mFile.getInputStream();
            fileName = getString(mFile.getOriginalFilename()).toLowerCase();
        } else {
            // 本地文件解析
            in = new FileInputStream(file);
            fileName = file.getName().toLowerCase();
        }
        Workbook book;
        if (fileName.endsWith(XLSX)) {
            book = new XSSFWorkbook(in);
        } else if (fileName.endsWith(XLS)) {
            POIFSFileSystem poifsFileSystem = new POIFSFileSystem(in);
            book = new HSSFWorkbook(poifsFileSystem);
        } else {
            return null;
        }
        in.close();
        return book;
    }

    private static JSONArray readSheet(Sheet sheet) {
        // 首行下标
        int rowStart = sheet.getFirstRowNum();
        // 尾行下标
        int rowEnd = sheet.getLastRowNum();
        // 获取表头行
        Row headRow = sheet.getRow(rowStart);
        if (headRow == null) {
            return new JSONArray();
        }
        int cellStart = headRow.getFirstCellNum();
        int cellEnd = headRow.getLastCellNum();
        Map<Integer, String> keyMap = new HashMap<>();
        for (int j = cellStart; j < cellEnd; j++) {
            // 获取表头数据
            String val = getCellValue(headRow.getCell(j));
            if (val != null && val.trim().length() != 0) {
                keyMap.put(j, val);
            }
        }
        // 如果表头没有数据则不进行解析
        if (keyMap.isEmpty()) {
            return (JSONArray) Collections.emptyList();
        }
        // 获取每行JSON对象的值
        JSONArray array = new JSONArray();
        // 如果首行与尾行相同,表明只有一行,返回表头数据
        if (rowStart == rowEnd) {
            JSONObject obj = new JSONObject();
            // 添加行号
            obj.put(ROW_NUM, 1);
            for (int i : keyMap.keySet()) {
                obj.put(keyMap.get(i), "");
            }
            array.add(obj);
            return array;
        }
        for (int i = rowStart + 1; i <= rowEnd; i++) {
            Row eachRow = sheet.getRow(i);
            JSONObject obj = new JSONObject();
            // 添加行号
            obj.put(ROW_NUM, i + 1);
            StringBuilder sb = new StringBuilder();
            for (int k = cellStart; k < cellEnd; k++) {
                if (eachRow != null) {
                    String val = getCellValue(eachRow.getCell(k));
                    // 所有数据添加到里面,用于判断该行是否为空
                    sb.append(val);
                    obj.put(keyMap.get(k), val);
                }
            }
            if (sb.length() > 0) {
                array.add(obj);
            }
        }
        return array;
    }

    private static String getCellValue(Cell cell) {
        // 空白或空
        if (cell == null || cell.getCellTypeEnum() == CellType.BLANK) {
            return "";
        }
        // String类型
        if (cell.getCellTypeEnum() == CellType.STRING) {
            String val = cell.getStringCellValue();
            if (val == null || val.trim().length() == 0) {
                return "";
            }
            return val.trim();
        }
        // 数字类型
        if (cell.getCellTypeEnum() == CellType.NUMERIC) {
            String s = cell.getNumericCellValue() + "";
            // 去掉尾巴上的小数点0
            if (Pattern.matches(".*\\.0*", s)) {
                return s.split("\\.")[0];
            } else {
                return s;
            }
        }
        // 布尔值类型
        if (cell.getCellTypeEnum() == CellType.BOOLEAN) {
            return cell.getBooleanCellValue() + "";
        }
        // 错误类型
        return cell.getCellFormula();
    }

    public static <T> void exportTemplate(HttpServletResponse response, String fileName, Class<T> clazz) {
        exportTemplate(response, fileName, fileName, clazz, false);
    }

    public static <T> void exportTemplate(HttpServletResponse response, String fileName, String sheetName,
                                          Class<T> clazz) {
        exportTemplate(response, fileName, sheetName, clazz, false);
    }

    public static <T> void exportTemplate(HttpServletResponse response, String fileName, Class<T> clazz,
                                          boolean isContainExample) {
        exportTemplate(response, fileName, fileName, clazz, isContainExample);
    }

    public static <T> void exportTemplate(HttpServletResponse response, String fileName, String sheetName,
                                          Class<T> clazz, boolean isContainExample) {
        // 获取表头字段
        List<ExcelClassField> headFieldList = getExcelClassFieldList(clazz);
        // 获取表头数据和示例数据
        List<List<Object>> sheetDataList = new ArrayList<>();
        List<Object> headList = new ArrayList<>();
        List<Object> exampleList = new ArrayList<>();
        Map<Integer, List<String>> selectMap = new LinkedHashMap<>();
        for (int i = 0; i < headFieldList.size(); i++) {
            ExcelClassField each = headFieldList.get(i);
            headList.add(each.getName());
            exampleList.add(each.getExample());
            LinkedHashMap<String, String> kvMap = each.getKvMap();
            if (kvMap != null && kvMap.size() > 0) {
                selectMap.put(i, new ArrayList<>(kvMap.values()));
            }
        }
        sheetDataList.add(headList);
        if (isContainExample) {
            sheetDataList.add(exampleList);
        }
        // 导出数据
        export(response, fileName, sheetName, sheetDataList, selectMap);
    }

    private static <T> List<ExcelClassField> getExcelClassFieldList(Class<T> clazz) {
        // 解析所有字段
        Field[] fields = clazz.getDeclaredFields();
        boolean hasExportAnnotation = false;
        Map<Integer, List<ExcelClassField>> map = new LinkedHashMap<>();
        List<Integer> sortList = new ArrayList<>();
        for (Field field : fields) {
            ExcelClassField cf = getExcelClassField(field);
            if (cf.getHasAnnotation() == 1) {
                hasExportAnnotation = true;
            }
            int sort = cf.getSort();
            if (map.containsKey(sort)) {
                map.get(sort).add(cf);
            } else {
                List<ExcelClassField> list = new ArrayList<>();
                list.add(cf);
                sortList.add(sort);
                map.put(sort, list);
            }
        }
        Collections.sort(sortList);
        // 获取表头
        List<ExcelClassField> headFieldList = new ArrayList<>();
        if (hasExportAnnotation) {
            for (Integer sort : sortList) {
                for (ExcelClassField cf : map.get(sort)) {
                    if (cf.getHasAnnotation() == 1) {
                        headFieldList.add(cf);
                    }
                }
            }
        } else {
            headFieldList.addAll(map.get(0));
        }
        return headFieldList;
    }

    private static ExcelClassField getExcelClassField(Field field) {
        ExcelClassField cf = new ExcelClassField();
        String fieldName = field.getName();
        cf.setFieldName(fieldName);
        ExcelExport annotation = field.getAnnotation(ExcelExport.class);
        // 无 ExcelExport 注解情况
        if (annotation == null) {
            cf.setHasAnnotation(0);
            cf.setName(fieldName);
            cf.setSort(0);
            return cf;
        }
        // 有 ExcelExport 注解情况
        cf.setHasAnnotation(1);
        cf.setName(annotation.value());
        String example = getString(annotation.example());
        if (!example.isEmpty()) {
            if (isNumeric(example) && example.length() < 8) {
                cf.setExample(Double.valueOf(example));
            } else {
                cf.setExample(example);
            }
        } else {
            cf.setExample("");
        }
        cf.setSort(annotation.sort());
        // 解析映射
        String kv = getString(annotation.kv());
        cf.setKvMap(getKvMap(kv));
        return cf;
    }

    private static LinkedHashMap<String, String> getKvMap(String kv) {
        LinkedHashMap<String, String> kvMap = new LinkedHashMap<>();
        if (kv.isEmpty()) {
            return kvMap;
        }
        String[] kvs = kv.split(";");
        if (kvs.length == 0) {
            return kvMap;
        }
        for (String each : kvs) {
            String[] eachKv = getString(each).split("-");
            if (eachKv.length != 2) {
                continue;
            }
            String k = eachKv[0];
            String v = eachKv[1];
            if (k.isEmpty() || v.isEmpty()) {
                continue;
            }
            kvMap.put(k, v);
        }
        return kvMap;
    }

    /**
     * 导出表格到本地
     *
     * @param file      本地文件对象
     * @param sheetData 导出数据
     */
    public static void exportFile(File file, List<List<Object>> sheetData) {
        if (file == null) {
            System.out.println("文件创建失败");
            return;
        }
        if (sheetData == null) {
            sheetData = new ArrayList<>();
        }
        Map<String, List<List<Object>>> map = new HashMap<>();
        map.put(file.getName(), sheetData);
        export(null, file, file.getName(), map, null);
    }

    /**
     * 导出表格到本地
     *
     * @param <T>      导出数据类似,和K类型保持一致
     * @param filePath 文件父路径(如:D:/doc/excel/)
     * @param fileName 文件名称(不带尾缀,如:学生表)
     * @param list     导出数据
     * @throws IOException IO异常
     */
    public static <T> File exportFile(String filePath, String fileName, List<T> list) throws IOException {
        File file = getFile(filePath, fileName);
        List<List<Object>> sheetData = getSheetData(list);
        exportFile(file, sheetData);
        return file;
    }

    /**
     * 获取文件
     *
     * @param filePath filePath 文件父路径(如:D:/doc/excel/)
     * @param fileName 文件名称(不带尾缀,如:用户表)
     * @return 本地File文件对象
     */
    private static File getFile(String filePath, String fileName) throws IOException {
        String dirPath = getString(filePath);
        String fileFullPath;
        if (dirPath.isEmpty()) {
            fileFullPath = fileName;
        } else {
            // 判定文件夹是否存在,如果不存在,则级联创建
            File dirFile = new File(dirPath);
            if (!dirFile.exists()) {
                boolean mkdirs = dirFile.mkdirs();
                if (!mkdirs) {
                    return null;
                }
            }
            // 获取文件夹全名
            if (dirPath.endsWith(String.valueOf(LEAN_LINE))) {
                fileFullPath = dirPath + fileName + XLSX;
            } else {
                fileFullPath = dirPath + LEAN_LINE + fileName + XLSX;
            }
        }
        System.out.println(fileFullPath);
        File file = new File(fileFullPath);
        if (!file.exists()) {
            boolean result = file.createNewFile();
            if (!result) {
                return null;
            }
        }
        return file;
    }

    private static <T> List<List<Object>> getSheetData(List<T> list) {
        // 获取表头字段
        List<ExcelClassField> excelClassFieldList = getExcelClassFieldList(list.get(0).getClass());
        List<String> headFieldList = new ArrayList<>();
        List<Object> headList = new ArrayList<>();
        Map<String, ExcelClassField> headFieldMap = new HashMap<>();
        for (ExcelClassField each : excelClassFieldList) {
            String fieldName = each.getFieldName();
            headFieldList.add(fieldName);
            headFieldMap.put(fieldName, each);
            headList.add(each.getName());
        }
        // 添加表头名称
        List<List<Object>> sheetDataList = new ArrayList<>();
        sheetDataList.add(headList);
        // 获取表数据
        for (T t : list) {
            Map<String, Object> fieldDataMap = getFieldDataMap(t);
            Set<String> fieldDataKeys = fieldDataMap.keySet();
            List<Object> rowList = new ArrayList<>();
            for (String headField : headFieldList) {
                if (!fieldDataKeys.contains(headField)) {
                    continue;
                }
                Object data = fieldDataMap.get(headField);
                if (data == null) {
                    rowList.add("");
                    continue;
                }
                ExcelClassField cf = headFieldMap.get(headField);
                // 判断是否有映射关系
                LinkedHashMap<String, String> kvMap = cf.getKvMap();
                if (kvMap == null || kvMap.isEmpty()) {
                    rowList.add(data);
                    continue;
                }
                String val = kvMap.get(data.toString());
                if (isNumeric(val)) {
                    rowList.add(Double.valueOf(val));
                } else {
                    rowList.add(val);
                }
            }
            sheetDataList.add(rowList);
        }
        return sheetDataList;
    }

    private static <T> Map<String, Object> getFieldDataMap(T t) {
        Map<String, Object> map = new HashMap<>();
        Field[] fields = t.getClass().getDeclaredFields();
        try {
            for (Field field : fields) {
                String fieldName = field.getName();
                field.setAccessible(true);
                Object object = field.get(t);
                map.put(fieldName, object);
            }
        } catch (IllegalArgumentException | IllegalAccessException e) {
            e.printStackTrace();
        }
        return map;
    }

    public static void exportEmpty(HttpServletResponse response, String fileName) {
        List<List<Object>> sheetDataList = new ArrayList<>();
        List<Object> headList = new ArrayList<>();
        headList.add("导出无数据");
        sheetDataList.add(headList);
        export(response, fileName, sheetDataList);
    }

    public static void export(HttpServletResponse response, String fileName, List<List<Object>> sheetDataList) {
        export(response, fileName, fileName, sheetDataList, null);
    }

    public static void exportManySheet(HttpServletResponse response, String fileName, Map<String, List<List<Object>>> sheetMap) {
        export(response, null, fileName, sheetMap, null);
    }


    public static void export(HttpServletResponse response, String fileName, String sheetName,
                              List<List<Object>> sheetDataList) {
        export(response, fileName, sheetName, sheetDataList, null);
    }

    public static void export(HttpServletResponse response, String fileName, String sheetName,
                              List<List<Object>> sheetDataList, Map<Integer, List<String>> selectMap) {

        Map<String, List<List<Object>>> map = new HashMap<>();
        map.put(sheetName, sheetDataList);
        export(response, null, fileName, map, selectMap);
    }

    public static <T, K> void export(HttpServletResponse response, String fileName, List<T> list, Class<K> template) {
        // list 是否为空
        boolean lisIsEmpty = list == null || list.isEmpty();
        // 如果模板数据为空,且导入的数据为空,则导出空文件
        if (template == null && lisIsEmpty) {
            exportEmpty(response, fileName);
            return;
        }
        // 如果 list 数据,则导出模板数据
        if (lisIsEmpty) {
            exportTemplate(response, fileName, template);
            return;
        }
        // 导出数据
        List<List<Object>> sheetDataList = getSheetData(list);
        export(response, fileName, sheetDataList);
    }

    public static void export(HttpServletResponse response, String fileName, List<List<Object>> sheetDataList, Map<Integer, List<String>> selectMap) {
        export(response, fileName, fileName, sheetDataList, selectMap);
    }

    private static void export(HttpServletResponse response, File file, String fileName,
                               Map<String, List<List<Object>>> sheetMap, Map<Integer, List<String>> selectMap) {
        // 整个 Excel 表格 book 对象
        SXSSFWorkbook book = new SXSSFWorkbook();
        // 每个 Sheet 页
        Set<Entry<String, List<List<Object>>>> entries = sheetMap.entrySet();
        for (Entry<String, List<List<Object>>> entry : entries) {
            List<List<Object>> sheetDataList = entry.getValue();
            Sheet sheet = book.createSheet(entry.getKey());
            Drawing<?> patriarch = sheet.createDrawingPatriarch();
            // 设置表头背景色(灰色)
            CellStyle headStyle = book.createCellStyle();
            headStyle.setFillForegroundColor(IndexedColors.GREY_80_PERCENT.index);
            headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
            headStyle.setAlignment(HorizontalAlignment.CENTER);
            headStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.index);
            // 设置表身背景色(默认色)
            CellStyle rowStyle = book.createCellStyle();
            rowStyle.setAlignment(HorizontalAlignment.CENTER);
            rowStyle.setVerticalAlignment(VerticalAlignment.CENTER);
            // 设置表格列宽度(默认为15个字节)
            sheet.setDefaultColumnWidth(15);
            // 创建合并算法数组
            int rowLength = sheetDataList.size();
            int columnLength = sheetDataList.get(0).size();
            int[][] mergeArray = new int[rowLength][columnLength];
            for (int i = 0; i < sheetDataList.size(); i++) {
                // 每个 Sheet 页中的行数据
                Row row = sheet.createRow(i);
                List<Object> rowList = sheetDataList.get(i);
                for (int j = 0; j < rowList.size(); j++) {
                    // 每个行数据中的单元格数据
                    Object o = rowList.get(j);
                    int v = 0;
                    if (o instanceof URL) {
                        // 如果要导出图片的话, 链接需要传递 URL 对象
                        setCellPicture(book, row, patriarch, i, j, (URL) o);
                    } else {
                        Cell cell = row.createCell(j);
                        if (i == 0) {
                            // 第一行为表头行,采用灰色底背景
                            v = setCellValue(cell, o, headStyle);
                        } else {
                            // 其他行为数据行,默认白底色
                            v = setCellValue(cell, o, rowStyle);
                        }
                    }
                    mergeArray[i][j] = v;
                }
            }
            // 合并单元格
            mergeCells(sheet, mergeArray);
            // 设置下拉列表
            setSelect(sheet, selectMap);
        }
        // 写数据
        if (response != null) {
            // 前端导出
            try {
                write(response, book, fileName);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            // 本地导出
            FileOutputStream fos;
            try {
                fos = new FileOutputStream(file);
                ByteArrayOutputStream ops = new ByteArrayOutputStream();
                book.write(ops);
                fos.write(ops.toByteArray());
                fos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 合并当前Sheet页的单元格
     *
     * @param sheet      当前 sheet 页
     * @param mergeArray 合并单元格算法
     */
    private static void mergeCells(Sheet sheet, int[][] mergeArray) {
        // 横向合并
        for (int x = 0; x < mergeArray.length; x++) {
            int[] arr = mergeArray[x];
            boolean merge = false;
            int y1 = 0;
            int y2 = 0;
            for (int y = 0; y < arr.length; y++) {
                int value = arr[y];
                if (value == CELL_COLUMN_MERGE) {
                    if (!merge) {
                        y1 = y;
                    }
                    y2 = y;
                    merge = true;
                } else {
                    merge = false;
                    if (y1 > 0) {
                        sheet.addMergedRegion(new CellRangeAddress(x, x, (y1 - 1), y2));
                    }
                    y1 = 0;
                    y2 = 0;
                }
            }
            if (y1 > 0) {
                sheet.addMergedRegion(new CellRangeAddress(x, x, (y1 - 1), y2));
            }
        }
        // 纵向合并
        int xLen = mergeArray.length;
        int yLen = mergeArray[0].length;
        for (int y = 0; y < yLen; y++) {
            boolean merge = false;
            int x1 = 0;
            int x2 = 0;
            for (int x = 0; x < xLen; x++) {
                int value = mergeArray[x][y];
                if (value == CELL_ROW_MERGE) {
                    if (!merge) {
                        x1 = x;
                    }
                    x2 = x;
                    merge = true;
                } else {
                    merge = false;
                    if (x1 > 0) {
                        sheet.addMergedRegion(new CellRangeAddress((x1 - 1), x2, y, y));
                    }
                    x1 = 0;
                    x2 = 0;
                }
            }
            if (x1 > 0) {
                sheet.addMergedRegion(new CellRangeAddress((x1 - 1), x2, y, y));
            }
        }
    }

    private static void write(HttpServletResponse response, SXSSFWorkbook book, String fileName) throws IOException {
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        String name = new String(fileName.getBytes("GBK"), "ISO8859_1") + XLSX;
        response.addHeader("Content-Disposition", "attachment;filename=" + name);
        ServletOutputStream out = response.getOutputStream();
        book.write(out);
        out.flush();
        out.close();
    }

    private static int setCellValue(Cell cell, Object o, CellStyle style) {
        // 设置样式
        cell.setCellStyle(style);
        // 数据为空时
        if (o == null) {
            cell.setCellType(CellType.STRING);
            cell.setCellValue("");
            return CELL_OTHER;
        }
        // 是否为字符串
        if (o instanceof String) {
            String s = o.toString();
            // 当数字类型长度超过8位时,改为字符串类型显示(Excel数字超过一定长度会显示为科学计数法)
            if (isNumeric(s) && s.length() < 8) {
                cell.setCellType(CellType.NUMERIC);
                cell.setCellValue(Double.parseDouble(s));
                return CELL_OTHER;
            } else {
                cell.setCellType(CellType.STRING);
                cell.setCellValue(s);
            }
            if (s.equals(ROW_MERGE)) {
                return CELL_ROW_MERGE;
            } else if (s.equals(COLUMN_MERGE)) {
                return CELL_COLUMN_MERGE;
            } else {
                return CELL_OTHER;
            }
        }
        // 是否为字符串
        if (o instanceof Integer || o instanceof Long || o instanceof Double || o instanceof Float) {
            cell.setCellType(CellType.NUMERIC);
            cell.setCellValue(Double.parseDouble(o.toString()));
            return CELL_OTHER;
        }
        // 是否为Boolean
        if (o instanceof Boolean) {
            cell.setCellType(CellType.BOOLEAN);
            cell.setCellValue((Boolean) o);
            return CELL_OTHER;
        }
        // 如果是BigDecimal,则默认3位小数
        if (o instanceof BigDecimal) {
            cell.setCellType(CellType.NUMERIC);
            cell.setCellValue(((BigDecimal) o).setScale(3, RoundingMode.HALF_UP).doubleValue());
            return CELL_OTHER;
        }
        // 如果是Date数据,则显示格式化数据
        if (o instanceof Date) {
            cell.setCellType(CellType.STRING);
            cell.setCellValue(formatDate((Date) o));
            return CELL_OTHER;
        }
        // 如果是其他,则默认字符串类型
        cell.setCellType(CellType.STRING);
        cell.setCellValue(o.toString());
        return CELL_OTHER;
    }

    private static void setCellPicture(SXSSFWorkbook wb, Row sr, Drawing<?> patriarch, int x, int y, URL url) {
        // 设置图片宽高
        sr.setHeight((short) (IMG_WIDTH * IMG_HEIGHT));
        // (jdk1.7版本try中定义流可自动关闭)
        try (InputStream is = url.openStream(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
            byte[] buff = new byte[BYTES_DEFAULT_LENGTH];
            int rc;
            while ((rc = is.read(buff, 0, BYTES_DEFAULT_LENGTH)) > 0) {
                outputStream.write(buff, 0, rc);
            }
            // 设置图片位置
            XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 0, 0, y, x, y + 1, x + 1);
            // 设置这个,图片会自动填满单元格的长宽
            anchor.setAnchorType(AnchorType.MOVE_AND_RESIZE);
            patriarch.createPicture(anchor, wb.addPicture(outputStream.toByteArray(), HSSFWorkbook.PICTURE_TYPE_JPEG));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static String formatDate(Date date) {
        if (date == null) {
            return "";
        }
        SimpleDateFormat format = new SimpleDateFormat(DATE_FORMAT);
        return format.format(date);
    }

    private static void setSelect(Sheet sheet, Map<Integer, List<String>> selectMap) {
        if (selectMap == null || selectMap.isEmpty()) {
            return;
        }
        Set<Entry<Integer, List<String>>> entrySet = selectMap.entrySet();
        for (Entry<Integer, List<String>> entry : entrySet) {
            int y = entry.getKey();
            List<String> list = entry.getValue();
            if (list == null || list.isEmpty()) {
                continue;
            }
            String[] arr = new String[list.size()];
            for (int i = 0; i < list.size(); i++) {
                arr[i] = list.get(i);
            }
            DataValidationHelper helper = sheet.getDataValidationHelper();
            CellRangeAddressList addressList = new CellRangeAddressList(1, 65000, y, y);
            DataValidationConstraint dvc = helper.createExplicitListConstraint(arr);
            DataValidation dv = helper.createValidation(dvc, addressList);
            if (dv instanceof HSSFDataValidation) {
                dv.setSuppressDropDownArrow(false);
            } else {
                dv.setSuppressDropDownArrow(true);
                dv.setShowErrorBox(true);
            }
            sheet.addValidationData(dv);
        }
    }

    private static boolean isNumeric(String str) {
        if (Objects.nonNull(str) && "0.0".equals(str)) {
            return true;
        }
        for (int i = str.length(); --i >= 0; ) {
            if (!Character.isDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    private static String getString(String s) {
        if (s == null) {
            return "";
        }
        if (s.isEmpty()) {
            return s;
        }
        return s.trim();
    }

}

3.Excel导出配置

package com.information.utils;


import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
   导出配置
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelExport {

    /** 字段名称 */
    String value();

    /** 导出排序先后: 数字越小越靠前(默认按Java类字段顺序导出) */
    int sort() default 0;

    /** 导出映射,格式如:0-未知;1-男;2-女 */
    String kv() default "";

    /** 导出模板示例值(有值的话,直接取该值,不做映射) */
    String example() default "";

}

4.Excel导入配置

package com.information.utils;


import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
   导入配置
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelImport {

    /** 字段名称 */
    String value();

    /** 导出映射,格式如:0-未知;1-男;2-女 */
    String kv() default "";

    /** 是否为必填字段(默认为非必填) */
    boolean required() default false;

    /** 最大长度(默认255) */
    int maxLength() default 255;

    /** 导入唯一性验证(多个字段则取联合验证) */
    boolean unique() default false;

}

 

三、添加user表和工具类使用方法

1.user表设置

package com.information.pojo;

import com.information.utils.ExcelExport;
import com.information.utils.ExcelImport;
import lombok.Data;
import lombok.Value;

@Data
public class ExcelUser {

    //导入时候获取数据行号--第几行
    private int rowNum;
    //数据导入的时候,如果某行存在错误,一般我们会将原始的数据拿出来分析--get这个字段即可
    private String rowData;
    //导入数据的时候,如果某行数据存在字段类型不正确 则会提示对应的错误信息
    private String rowTips;
    //ExcelImport 导入工具类中 required = true 添加必填项 unique = true 标识唯一性不可重复
    @ExcelImport(value = "姓名")
    @ExcelExport(value = "姓名",example = "张三")
    private String name;
    //ExcelImport 导入的设置
    //ExcelExport 导出的设置
    @ExcelImport("年龄")
    @ExcelExport(value = "年龄",example = "18")
    private Integer age;
    //在导入数据的时候将男女自动转换1--2
    @ExcelImport(value = "性别",kv = "1-男;2-女")
    //在导出数据的时候将男女自动转换1--2
    @ExcelExport(value = "性别",example = "男",kv = "1-男;2-女")
    private String sex;
    //maxLength = 11 电话控制大小
    //ExcelExport 导出工具类中 example 的意思是 下载样式模版的时候添加的一条样式数据
    @ExcelImport(value = "电话")
    @ExcelExport(value = "电话",example = "13333333333")
    private String tel;
    @ExcelImport("城市")
    @ExcelExport(value = "城市",example = "上海")
    private String city;
    @ExcelImport("头像")
    @ExcelExport(value = "城市",example = "www.touxiang.com")
    private String avatar;
}

 

2.工具类的使用

 /**
     * 此方法在导入的时候 1男 2 女 sex=1性别自动转换  
     * rowNum=2 自动获取Excel 数据行数
     *  RowTips  提醒错误信息
     * @param file
     * @throws Exception
     */
    @PostMapping("/import")
    @ResponseBody
    public JSONObject importUser(@RequestPart("file")MultipartFile file) throws Exception {
        List<ExcelUser> users = ExcelUtils.readMultipartFile(file, ExcelUser.class);
        for (ExcelUser user : users) {
            JSONObject object = new JSONObject();
            System.out.println(user.getSex());
            System.out.println(user.getName());
            System.out.println(user.getAge());
            System.out.println(user.getTel());
            System.out.println(user.getCity());
            System.out.println(user.getAvatar());
            //错误提示
            System.out.println(user.getRowTips());
            //列如我们手机号在user表中设置 长度11 那么在导入的时候你是12
            //将提示您的第2行数据的手机号码超过11位
            object.put(Consts.MSG,"您的第"+user.getRowNum()+"行"+user.getRowTips());
            object.put(Consts.CODE,"0");
            return object;
        }
        return null;
    }

    /**
     * 导入多Sheet页 
     * @param file
     * @throws Exception
     */
    @PostMapping("/import1")
    @ResponseBody
    public void upload(@RequestPart("file") MultipartFile file) throws Exception {
        Map<String, JSONArray> map = ExcelUtils.readFileManySheet(file);
        map.forEach((key, value) -> {
            System.out.println("Sheet名称:" + key);
            System.out.println("Sheet数据:" + value);
            System.out.println("----------------------");
        });
    }

    /**
     * 下载样式模版
     * 也就是我们在对象表中设置的example关键字 
     * @param response
     */
    @GetMapping("/export")
    @ResponseBody
    public void export(HttpServletResponse response) {
        ExcelUtils.exportTemplate(response, "用户表", ExcelUser.class,true);
    }

    /**
     * 下载查询数据--导出
     * @param response
     */
    @GetMapping("/exportdc")
    public void exportdc(HttpServletResponse response) {
        List<ExcelUser> userList = new ArrayList<>();
        ExcelUser user1 = new ExcelUser();
        user1.setName("张三");
        user1.setAge (18);
        //性别我们也有设置 1男2女
        //ExcelImport导入的设置 
        //@ExcelImport(value = "性别",kv = "1-男;2-女")
        //ExcelExport 导出的设置 
        //@ExcelExport(value = "性别",kv = "1-男;2-女")
        user1.setSex("1");
        user1.setCity("成都");
        user1.setTel("13800000");
        user1.setAvatar("www");
        userList.add(user1);
        ExcelUtils.export(response,  "用户表", userList, ExcelUser.class);
    }

标签:return,String,int,Excel,private,导入,static,new,java
From: https://www.cnblogs.com/yaoyaobky/p/18382259

相关文章

  • Java中的API网关:Spring Cloud Gateway与Zuul
    在微服务架构中,API网关扮演着至关重要的角色。它作为系统的入口,负责请求的路由、负载均衡、认证授权、限流熔断等功能。本文将深入探讨两个流行的JavaAPI网关解决方案:SpringCloudGateway和NetflixZuul,并通过详细的解释和代码示例展示它们的使用方法和优缺点。1.API网关概......
  • Java中的序列化与反序列化深度剖析
    序列化与反序列化在Java开发中扮演了重要角色,特别是在数据持久化、RPC(远程过程调用)以及分布式系统中。本篇博客将详细解析Java中的序列化机制,讨论常见的序列化框架,并提供实际代码示例帮助理解。什么是序列化与反序列化?序列化(Serialization):将Java对象转换为字节流的过程,以便将......
  • java+vue计算机毕设线上图书商城系统【源码+开题+论文】
    本系统(程序+源码)带文档lw万字以上文末可获取一份本项目的java源码和数据库参考。系统程序文件列表开题报告内容研究背景随着互联网技术的飞速发展,电子商务已成为现代商业活动的重要组成部分,深刻改变着人们的消费习惯。在数字化阅读日益普及的今天,线上图书商城系统应运而......
  • java+vue计算机毕设社区团购平台【源码+开题+论文】
    本系统(程序+源码)带文档lw万字以上文末可获取一份本项目的java源码和数据库参考。系统程序文件列表开题报告内容研究背景随着互联网技术的飞速发展和智能设备的普及,电子商务行业正经历着前所未有的变革。社区团购平台作为新零售模式的一种重要形式,近年来迅速崛起并受到广......
  • java+vue计算机毕设四川工商学院疫情防控系统的设计与实现【源码+开题+论文】
    本系统(程序+源码)带文档lw万字以上文末可获取一份本项目的java源码和数据库参考。系统程序文件列表开题报告内容研究背景随着全球疫情的持续演变,高校作为人员密集、流动性大的场所,其疫情防控工作显得尤为重要。四川工商学院作为一所培养未来社会栋梁的高等学府,面对疫情挑......
  • 3.Python操控Excel之写
    1.openpyxl读取excel的格式流程2.openpyxl修改sheet标题并生成新excel保存3..create_sheet方法添加sheet,.remove方法删除sheet4.excel数据填充的四种方式5.1.更新excel内一列数据中的部分数据_代码部分5.2.更新excel内一列数据中的部分数据_执行结果......
  • JavaScript 的事件循环、宏任务、微任务
    JavaScrtipt执行顺序首先,必须要明确,在JavaScript中,所有任务都在主线程上执行。任务执行过程分为同步任务和异步任务两个阶段。异步任务的处理经历两个主要阶段:EventTable(事件表)和EventQueue(事件队列)。EventTable存储了宏任务的相关信息,包括事件监听和相应的回调函数。当特定......
  • Java中方法重写的学习
    方法重写目录方法重写方法重写的规则方法重载的规则方法重写的规则在Java中,方法重写(Overriding)是面向对象编程中的一个核心概念,它允许子类提供一个与父类相同名称、相同参数列表的方法,以实现或修改父类方法的行为。方法重写必须遵循一定的规则,以确保程序的正确性和可维护性。......
  • 滚雪球学Java(91):Java GUI编程实战:精通组件开发技巧,真有点东西!
      咦咦咦,各位小可爱,我是你们的好伙伴——bug菌,今天又来给大家普及JavaSE啦,别躲起来啊,听我讲干货还不快点赞,赞多了我就有动力讲得更嗨啦!所以呀,养成先点赞后阅读的好习惯,别被干货淹没了哦~......
  • JVM(Java Virtual Machine,Java虚拟机)
    JVM(JavaVirtualMachine,Java虚拟机)是Java平台的核心组成部分,它负责运行Java程序。JVM使得Java程序能够“一次编写,到处运行”(WriteOnce,RunAnywhere),这是Java语言的一个重要特性。JVM通过在不同的操作系统上提供统一的运行时环境来实现这一特性。JVM的主要组成部分JVM主......