目录
1、文件上传本地
1.1 原理
1.2 如何使用文件上传
1.2.1 引入文件上传的依赖
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.10.RELEASE</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<!--servlet依赖-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<!--jackson依赖:把controller层方法返回的java对象转化为json字符串-->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.13.3</version>
</dependency>
<!--文件上传依赖-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
</dependencies>1.2.2 配置文件上传拦截器
<!--文件上传解析器 id:必须为multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!--设置文件上传的大小 单位为byte字节 1M=1024kb=1024b 10*1024*1024-->
<property name="maxUploadSize" value="10485760"/>
<!--设置编码-->
<property name="defaultEncoding" value="utf-8"/>
</bean>
1.2.3 完成文件上传的代码
<%--表单: 提交方式必须为post enctype编码:multipart/form-data文件编码--%>
<form method="post" action="/upload" enctype="multipart/form-data">
<%--input必须设置文件文件框 而且必须起名称--%>
选择上传的文件:<input type="file" name="myfile"/><br>
<input type="submit" value="上传"/>
</form>@Controller
public class UploadController {
/**
*
* @param myfile 接受你上传的文件对象信息封装到该类。该类中可以获取上传文件的信息。比如:文件名 文件大小 文件后缀等
* 这个名称必须为文件上传表单的文件框的名称一致
* @return
*/
@PostMapping("/upload")
public String upload(MultipartFile myfile, HttpServletRequest request) throws IOException {
//获取tomcat上下文中的指定目录的路径
String realPath = request.getSession().getServletContext().getRealPath("/upload");
//根据上面的路径创建一个文件对象
File file=new File(realPath);
//如果没有该目录则创建
if (!file.exists()) {
file.mkdirs();
}
//把上传的文件转移到upload目录下--重名覆盖了
String uuid = UUID.randomUUID().toString().replace("-", "");
File target=new File(realPath+"/"+(uuid+myfile.getOriginalFilename()));
myfile.transferTo(target);
return "success";
}
}2、文件上传oss服务器
2.1 为什么需要上传到oss服务器
如果项目搭建了集群。那么导致文件数据无法共享。
如果项目的target删除了。导致文件数据丢失。
2.2 如何使用oss
2.2.1 开启oss服务
点击上面链接，跳转到阿里云的oss服务器页面，完成登录后，会进入oss管理控制台，如图所示
然后点击创建Bucket，操作如下图
2.2.2 在Java中引入依赖
<dependency>
<groupId>com.aliyun.oss</groupId>
<artifactId>aliyun-sdk-oss</artifactId>
<version>3.15.1</version>
</dependency>2.2.3 查看自己ID和密钥
2.2.4 代码
@PostMapping("/upload2")
public String upload2(MultipartFile myfile){
// Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。
String endpoint = "oss-cn-beijing.aliyuncs.com";
// 填写Bucket名称，例如examplebucket。
String bucketName = "XXXXX";
//上传到oss后的名字
String objectName = UUID.randomUUID().toString().replace("-","")+myfile.getOriginalFilename();
// 创建OSSClient实例。
/**
* String endpoint,自己的endpoint
* String accessKeyId, 自己的id
* String secretAccessKey自己的密钥
*/
String accessKeyId="XXXXXXX";
String secretAccessKey="XXXXXXX";
OSS ossClient = new OSSClientBuilder().build(endpoint,accessKeyId,secretAccessKey);
try {
InputStream inputStream = myfile.getInputStream();
// 创建PutObjectRequest对象。
PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, objectName, inputStream);
// 创建PutObject请求。
PutObjectResult result = ossClient.putObject(putObjectRequest);
} catch (Exception oe) {
}
finally {
if (ossClient != null) {
ossClient.shutdown();
}
}
return "success";
}3、案例
springmvc+jdbc+elementui+vue
添加和展示所有的功能
3.1 引入相关依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.ykq</groupId>
<artifactId>qy174-springmvc04</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.10.RELEASE</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<!--servlet依赖-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<!--jackson依赖:把controller层方法返回的java对象转化为json字符串-->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.13.3</version>
</dependency>
<!--文件上传依赖-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<!--oss的依赖-->
<dependency>
<groupId>com.aliyun.oss</groupId>
<artifactId>aliyun-sdk-oss</artifactId>
<version>3.15.1</version>
</dependency>
<!--mysql的jar-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<!--druid-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.8</version>
</dependency>
</dependencies>
</project>3.2 创建实体类
@Data
public class Student implements Serializable {
private Integer id;
private String name;
private String phone;
private String email;
private Integer age;
private Byte gender;
private Date createtime;
private String head;
}3.3 创建controller层
3.3.1 创建StudentController
@Controller
@RequestMapping("/student")
public class StudentController {
private StudentDao studentDao=new StudentDao();
@GetMapping("/list")
@ResponseBody //把java对象转化为json字符串
public List<Student> list(){
List<Student> list = studentDao.findAll();
return list;
}
@PostMapping("/add")
@ResponseBody //把java对象转化为json字符串
public int add(@RequestBody Student student){
int add = studentDao.add(student.getName(), student.getPhone(), student.getEmail(), student.getAge(), student.getGender(), student.getHead());
return add;
}
}3.3.2 创建UploadController
@Controller
public class UploadController {
/**
*
* @param myfile 接受你上传的文件对象信息封装到该类。该类中可以获取上传文件的信息。比如:文件名 文件大小 文件后缀等
* 这个名称必须为文件上传表单的文件框的名称一致
* @return
*/
@PostMapping("/upload")
public String upload(MultipartFile myfile, HttpServletRequest request) throws IOException {
//获取tomcat上下文中的指定目录的路径
String realPath = request.getSession().getServletContext().getRealPath("/upload");
//根据上面的路径创建一个文件对象
File file=new File(realPath);
//如果没有该目录则创建
if (!file.exists()) {
file.mkdirs();
}
//把上传的文件转移到upload目录下--重名覆盖了
String uuid = UUID.randomUUID().toString().replace("-", "");
File target=new File(realPath+"/"+(uuid+myfile.getOriginalFilename()));
myfile.transferTo(target);
return "success";
}
@PostMapping("/upload2")
@ResponseBody
public String upload2(MultipartFile file){
// Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。
String endpoint = "oss-cn-beijing.aliyuncs.com";
// 填写Bucket名称，例如examplebucket。
String bucketName = "qy174-8888";
//上传到oss后的名字
String objectName = UUID.randomUUID().toString().replace("-","")+file.getOriginalFilename();
// 创建OSSClient实例。
/**
* String endpoint,自己的endpoint
* String accessKeyId, 自己的id
* String secretAccessKey自己的密钥
* XX
* XXX
*/
String accessKeyId="XXX";
String secretAccessKey="XXX";
OSS ossClient = new OSSClientBuilder().build(endpoint,accessKeyId,secretAccessKey);
try {
InputStream inputStream = file.getInputStream();
// 创建PutObjectRequest对象。
PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, objectName, inputStream);
// 创建PutObject请求。
PutObjectResult result = ossClient.putObject(putObjectRequest);
String path="https://"+bucketName+"."+endpoint+"/"+objectName;
return path;
} catch (Exception oe) {
}
finally {
if (ossClient != null) {
ossClient.shutdown();
}
}
return "失败";
}
}
3.4 创建dao层
3.4.1 BaseDao
public class BaseDao {
protected Connection conn;
protected PreparedStatement ps;
protected ResultSet rs;
//数据源对象
private static DataSource dataSource;
//静态代码块中
static {
try {
//创建一个属性对象
Properties properties = new Properties();
//加载属性文件
InputStream inputStream = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
properties.load(inputStream);
//获取连接池对象
dataSource = DruidDataSourceFactory.createDataSource(properties);
} catch (Exception e) {
e.printStackTrace();
}
}
//获取连接对象
public void getConn() throws Exception{
conn = dataSource.getConnection();
}
//关闭资源
public void closeAll(){
if(rs!=null){
try {
rs.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if(ps!=null){
try {
ps.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
//通用的增删改方法
public int edit(String sql,Object...params){
try {
getConn();
ps=conn.prepareStatement(sql);
//为占位符赋值
for(int i=0;i<params.length;i++){
ps.setObject(i+1,params[i]);
}
int row = ps.executeUpdate();
return row;
} catch (Exception e) {
e.printStackTrace();
} finally {
closeAll();
}
return 0;
}
}
/**
1. 四个属性: connection preparedStatement ResultSet DataSource
2. 静态代码块:[获取连接池]
3. 获取连接对象的方法
4. 关闭资源方法
5. 通用的增删改方法
*/3.4.2 StudentDao
public class StudentDao extends BaseDao {
//求总条数 select count(*) from t_student
public int getCount(){
try {
getConn();
String sql="select count(*) as c from t_student";
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
while (rs.next()){
int c = rs.getInt("c");
return c;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
closeAll();
}
return 0;
}
//查询所有学员信息--单元测试
public List<Student> findAll(){
List<Student> list=new ArrayList<Student>();
try {
getConn();
String sql="select * from t_student";
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
while (rs.next()){
Student s=new Student();
s.setId(rs.getInt("id"));
s.setPhone(rs.getString("phone"));
s.setEmail(rs.getString("email"));
s.setAge(rs.getInt("age"));
s.setName(rs.getString("name"));
s.setCreatetime(rs.getDate("createtime"));
s.setGender(rs.getByte("gender"));
s.setHead(rs.getString("head"));
list.add(s);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
closeAll();
}
return list;
}
//根据id查询学员信息
public Student findById(String id){
Student s=null;
try {
getConn();
String sql="select * from t_student where id=?";
ps=conn.prepareStatement(sql);
ps.setObject(1,id);
rs=ps.executeQuery();
while (rs.next()){
s=new Student();
s.setId(rs.getInt("id"));
s.setPhone(rs.getString("phone"));
s.setEmail(rs.getString("email"));
s.setAge(rs.getInt("age"));
s.setName(rs.getString("name"));
s.setCreatetime(rs.getDate("createtime"));
s.setGender(rs.getByte("gender"));
s.setHead(rs.getString("head"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
closeAll();
}
return s;
}
//添加方法
public int add(String name,String phone,String email,int age,int gender,String head){
String sql="insert into t_student(id,name,phone,email,age,createtime,gender,head) values(null,?,?,?,?,now(),?,?)";
return edit(sql,name,phone,email,age,gender,head);
}
//修改
public int update(String id,String name,String phone,String email,int age,int gender){
String sql="update t_student set name=?,phone=?,email=?,age=?,gender=?,createtime=now() where id=?";
return edit(sql,name,phone,email,age,gender,id);
}
//删除方法
public int delete(String id){
String sql="delete from t_student where id=?";
return edit(sql,id);
}3.5 配置SpringMvc配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--com.ykq 扫描该包以及该包下的子包-->
<context:component-scan base-package="com.Hs"/>
<!--开启注解驱动 不要导错mvc 默认使用的不是注解模式-->
<mvc:annotation-driven/>
<!--放行静态资源-->
<mvc:default-servlet-handler/>
<!--视图解析-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/views/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--文件上传解析器 id:必须为multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!--设置文件上传的大小 单位为byte字节 1M=1024kb=1024b 10*1024*1024-->
<property name="maxUploadSize" value="10485760"/>
<!--设置编码-->
<property name="defaultEncoding" value="utf-8"/>
</bean>
</beans>3.6 编写upload.jsp文件
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<%--表单: 提交方式必须为post enctype编码:multipart/form-data文件编码--%>
<form method="post" action="/upload2" enctype="multipart/form-data">
<%--input必须设置文件文件框 而且必须起名称--%>
选择上传的文件:<input type="file" name="myfile"/><br>
<input type="submit" value="上传"/>
</form>
</body>
</html>