SpringMvc文件上传和json处理

文件上传

pom依赖

<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.3</version>
</dependency>

springmvc.xml

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 必须和用户JSP 的pageEncoding属性一致,以便正确解析表单的内容 -->
        <property name="defaultEncoding" value="UTF-8"></property>
        <!-- 文件最大大小(字节) 1024*1024*50=50M-->
        <property name="maxUploadSize" value="52428800"></property>
        <!--resolveLazily属性启用是为了推迟文件解析,以便捕获文件大小异常-->
        <property name="resolveLazily" value="true"/>
</bean>

jsp页面

<%--
  Created by IntelliJ IDEA.
  User: dell
  Date: 2019/9/29
  Time: 19:57
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>上传图片</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/upload" method="post" enctype="multipart/form-data">
    <input type="file" name="xxx">
    <input type="submit" value="上传">
</form>

</body>
</html>

代码

    @RequestMapping("/upload")
    @ResponseBody
    public String upload(HttpServletRequest request, MultipartFile xxx){
        try {
            FileUtils.copyInputStreamToFile(xxx.getInputStream(),new File("E://temp/"+xxx.getOriginalFilename()));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "上传成功";
    }

如果要访问这张图片要配置映射文件:

结果:

json返回处理:

在请求方法前加这个@ResponseBody
  @ResponseBody
    @RequestMapping("/jsonStr2")
    public Map jsonStr2(){
        return bookService.listPager(new Book(),new PageBean()).get(0);

    }

结果

json返回处理的工具类

package com.cjh.util;

public class JSONResult {

    // 响应业务状态
    private Integer status;

    // 响应消息
    private String msg;

    // 响应中的数据
    private Object data;
    
    private String ok;    // 不使用

    public static JSONResult build(Integer status, String msg, Object data) {
        return new JSONResult(status, msg, data);
    }

    public static JSONResult ok(Object data) {
        return new JSONResult(data);
    }

    public static JSONResult ok() {
        return new JSONResult(null);
    }
    
    public static JSONResult errorMsg(String msg) {
        return new JSONResult(500, msg, null);
    }
    
    public static JSONResult errorMap(Object data) {
        return new JSONResult(501, "error", data);
    }
    
    public static JSONResult errorTokenMsg(String msg) {
        return new JSONResult(502, msg, null);
    }
    
    public static JSONResult errorException(String msg) {
        return new JSONResult(555, msg, null);
    }

    public JSONResult() {

    }

    public JSONResult(Integer status, String msg, Object data) {
        this.status = status;
        this.msg = msg;
        this.data = data;
    }

    public JSONResult(Object data) {
        this.status = 200;
        this.msg = "OK";
        this.data = data;
    }

    public Boolean isOK() {
        return this.status == 200;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    public String getOk() {
        return ok;
    }

    public void setOk(String ok) {
        this.ok = ok;
    }

}

测试

    @ResponseBody
    @RequestMapping("/jsonStr3")
    public JSONResult jsonStr3(){
        return JSONResult.ok("这里是data对象");

    }


    @ResponseBody
    @RequestMapping("/jsonStr4")
    public JSONResult jsonStr4(){
        return JSONResult.errorMsg("请求异常");

    }
}

原文地址:https://www.cnblogs.com/chenjiahao9527/p/11614170.html