1. 一般的后管在分页列表管理里都有导出功能
我们的项目是先有分页管理，后面需求要求所有的分页再增加导出功用，所以后端采用统一导出的策略
根据不同业务场景，多次调用对应的分页接口，然后统一输出到excel里
2. 对应的配置类(后期将配置转化到数据库里)
import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.lang.Pair;
import com.google.common.base.Strings;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import reactor.util.function.Tuple2;
import reactor.util.function.Tuples;
import javax.annotation.PostConstruct;
import java.util.*;
@Data
@ConfigurationProperties(prefix = "export.excel.manager")
public class ExportExcelManagerProperty {
private Map<String, ExportExcelManagerTemplate> templates;
@Data
public static class ExportExcelManagerTemplate {
/**
* 导出的文件名
*/
private String fileName;
/**
* 分页列表接口对应的bean名称
*/
private String beanName;
/**
* 分页列表接口对应的method名称
*/
private String methodName;
/**
* 分页接口对应的请求类
*/
private String requestBodyClassName;
/**
* 分页接口对应的返回类(必须是PageInfo<?>类型)
*/
private String responseBodyClassName;
/**
* 动态配置的header头(由于不同国家输出表格的header头不一样,所以不能直接在dto上打 @ExcelProperty来解决)
*/
private List<Pair<String, String>> headerFiledMap;
private String headerFiled;
/**
* 动态配置的输出列及转换公式
*/
private Map<String, String> fieldValueMapping;
private Map<String, Map<String, String>> fieldValueMappingFunction;
}
@PostConstruct
private void init() {
//
templates.entrySet().stream()
.filter(p -> !Strings.isNullOrEmpty(p.getValue().getHeaderFiled()))
.forEach(p -> {
System.out.println(p.getValue().getHeaderFiled());
p.getValue().headerFiledMap = toListTuple(p.getValue().getHeaderFiled());
});
for (Map.Entry<String, ExportExcelManagerTemplate> entry : templates.entrySet()) {
Map<String, Map<String, String>> rs = new HashMap<>();
for (Map.Entry<String, String> entry2 : entry.getValue().getFieldValueMapping().entrySet()) {
if (!Strings.isNullOrEmpty(entry2.getValue())) {
rs.put(entry2.getKey(), toMap(entry2.getValue()));
}
}
entry.getValue().fieldValueMappingFunction = rs;
}
System.out.println(this);
}
private static List<Pair<String, String>> toListTuple(String str) {
return toListTuple(str, "&", "=");
}
private static List<Pair<String, String>> toListTuple(String str, String itemSpliter, String keyValueSpliter) {
List<Pair<String, String>> result = new ArrayList<>();
Arrays.stream(str.split(itemSpliter)).forEach(p -> {
String[] split = p.split(keyValueSpliter);
result.add(Pair.of(split[0], split[1]));
});
return result;
}
private static Map<String, String> toMap(String str) {
return toMap(str, "&", "=");
}
private static Map<String, String> toMap(String str, String itemSpliter, String keyValueSpliter) {
Map<String, String> result = new TreeMap<>();
Arrays.stream(str.split(itemSpliter)).forEach(p -> {
String[] split = p.split(keyValueSpliter);
result.put(split[0], split[1]);
});
return result;
}
}
2. 服务层
@Autowired
private ExportExcelManagerProperty exportExcelManagerProperty;
private static final Map<String, Class> CLASS_MAP = new ConcurrentHashMap<>(32);
/**
* 增加导出记录
*
* @return
*/
@Override
public Pair<String, byte[]> exportExcel(String type, JSONObject req) {
ExportExcelManagerProperty.ExportExcelManagerTemplate template = exportExcelManagerProperty
.getTemplates().get(type);
Assert.notNull(template, "不支持的导出类型,请联系后端开发配置该类型");
Class requestBodyClassClass = getClass(template.getRequestBodyClassName());
Class responseBodyClassClass = getClass(template.getResponseBodyClassName());
// 如果当前的response类已存在 @ExcelProperty 注解,则直接使用
boolean existEasyExcelProperty = hasEasyExcelProperty(responseBodyClassClass);
Object pageDto = JSONObject.parseObject(req.toJSONString(), requestBodyClassClass);
int i = 0;
List<String> header = template.getHeaderFiledMap().stream()
.map(p -> p.getKey()).collect(Collectors.toList());
List<String> fields = template.getHeaderFiledMap().stream()
.map(p -> p.getValue()).collect(Collectors.toList());
List<Object> data = new LinkedList<>();
do {
if (pageDto instanceof BasePageDto) {
((BasePageDto) pageDto).setPageNum(++i);
((BasePageDto) pageDto).setPageSize(1000);
} else break;
String sourceBeanName = template.getBeanName();
Object sourceBean = sourceBeanName.contains(".") ? SpringBeanUtil.getBean(getClass(sourceBeanName)) : SpringBeanUtil.getBean(sourceBeanName);
if (null == sourceBean) {
throw new RuntimeException("配置的bean不合法");
}
Object result = InvokeMethodUtil.invokeMethod(sourceBean, template.getMethodName(), pageDto);
if (null == result) {
log.warn("调用bean方法异常! type:{}, req:{}", type, req);
throw new RuntimeException("配置的bean方法不合法");
}
PageInfo<Object> pageData = getRestResponseBody(result);
// 这里还需要根据header头做映射
if (existEasyExcelProperty) {
// 实际结构为 List<Object> ,Object为java类实例
data.addAll(pageData.getList());
} else {
// 实际结构为 List<List<Object>>,Object的原始类型
data.addAll(handleData(pageData.getList(), responseBodyClassClass, fields, template.getFieldValueMappingFunction()));
}
if (!pageData.isHasNextPage()) {
break;
}
} while (i < 1000);
if (existEasyExcelProperty) {
return Pair.of(template.getFileName(), writeFile(responseBodyClassClass, data));
} else {
return Pair.of(template.getFileName(), writeFile(header, data));
}
}
private static Class getClass(String className) {
Class tClass = CLASS_MAP.get(className);
if (tClass != null) {
return tClass;
}
tClass = getClassImpl(className);
CLASS_MAP.put(className, tClass);
return tClass;
}
private static Class getClassImpl(String className) {
Class<?> paramClass = null;
try {
paramClass = Class.forName(className);
return paramClass;
} catch (ClassNotFoundException e) {
throw new RuntimeException("配置的ParamClassName无法识别");
}
}
private boolean hasEasyExcelProperty(Class responseBodyClassClass) {
Map<Field, ExcelProperty> allField = AnnotationExtentUtil.getAllField(responseBodyClassClass, ExcelProperty.class);
return allField.size() > 0;
}
private static byte[] writeFile(Class responseBodyClassClass, List<Object> data) {
try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
ExcelWriter excelWriter = EasyExcelFactory.write().head(responseBodyClassClass).file(os).build();
WriteSheet writeSheet = EasyExcelFactory.writerSheet(0).build();
excelWriter.write(data, writeSheet);
excelWriter.finish();
return os.toByteArray();
} catch (IOException e) {
//e.printStackTrace();
log.error("生成 excel 异常!", e);
throw new RuntimeException("生成 excel 异常!");
}
}
private static byte[] writeFile(List<String> headerName, List<Object> data) {
List<List<String>> header = headerName.stream()
.map(p -> Collections.singletonList(p))
.collect(Collectors.toList());
try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
ExcelWriter excelWriter = EasyExcelFactory.write().head(header).file(os).build();
WriteSheet writeSheet = EasyExcelFactory.writerSheet(0).build();
excelWriter.write(data, writeSheet);
excelWriter.finish();
return os.toByteArray();
} catch (IOException e) {
//e.printStackTrace();
log.error("生成 excel 异常!", e);
throw new RuntimeException("生成 excel 异常!");
}
}
/**
* 对RestResponse做特殊处理，只取其data
*/
public List<List<Object>> handleData(List<Object> data, Class responseBodyClass, List<String> fields, Map<String, Map<String, String>> functionMap) {
List<List<Object>> result = new ArrayList<>(data.size());
for (Object obj : data) {
List<Object> item = new ArrayList<>(fields.size());
for (String filed : fields) {
Object fieldValue = ReflectionUtils.getFieldValue(obj, filed);
Map<String, String> function = functionMap.get(filed);
item.add(convertValue(fieldValue, function));
}
result.add(item);
}
return result;
}
private static Object convertValue(Object v, Map<String, String> function) {
if (v == null) {
return null;
}
if (function == null) {
if (v instanceof List) {
return String.join(",", (List) v);
} else {
return v;
}
}
if (v instanceof List) {
return ((List<?>) v).stream()
.map(p -> function.containsKey(p.toString())
? function.get(p.toString())
: p.toString()
)
.collect(Collectors.joining(","));
} else {
return function.containsKey(v.toString())
? function.get(v.toString())
: v;
}
}
/**
* 对RestResponse做特殊处理，只取其data
*/
public PageInfo<Object> getRestResponseBody(Object result) {
if (!(result instanceof RestResponse)) {
throw new RuntimeException("返回类型必须是RestResponse结构");
}
RestResponse<?> restResponse = (RestResponse<?>) result;
if (!RestResponse.SUCC_CODE.equalsIgnoreCase(restResponse.getResultCode())) {
log.error("ApiOperationLogAspect.handleRestResponse resultCode not successful :{}", JSONObject.toJSONString(restResponse));
return null;
}
Object data = restResponse.getData();
if (null == data) {
log.error("ApiOperationLogAspect.handleRestResponse RestResponse data is empty");
}
if (data instanceof PageInfo) {
return (PageInfo) (data);
}
throw new RuntimeException("返回类型必须是RestResponse<PageInfo<*>>结构");
}
标签：通用,String,导出,excel,List,private,new,return,data From： https://www.cnblogs.com/zhshlimi/p/16624075.html