Springmvc 文件上传和json处理

SpringMVC文件上传

1.相关依赖

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

2.在springmvc-servlet.xml中配置文件上传解析器

<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>

3.upload.jsp:

<%--
  Created by IntelliJ IDEA.
  User: Admin
  Date: 2019/9/29
  Time: 20:28
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>文件上传</title>
</head>
<body>
    <form action="${pageContext.request.contextPath}/upload" method="post" enctype="multipart/form-data">
        上传文件:<input type="file" name="img" >
        <button type="submit">提交</button>
    </form>


</body>
</html>

HelloController:

@RequestMapping("/upload")
    public String upload(MultipartFile img) throws IOException {
        FileUtils.copyInputStreamToFile(img.getInputStream(),new File("D:/yyy/"+img.getOriginalFilename()));
        return "forward:upload";
    }

json处理

在方法上面加上@ResponseBody这个注解就好了

@ResponseBody
    @RequestMapping("/jsonData1")
    public List<Map> jsonData1(){
        return bookservice.listPager(new Book(),new PageBean());
    }

    @ResponseBody
    @RequestMapping("/jsonData2")
    public Map jsonData2(){
        return bookservice.listPager(new Book(),new PageBean()).get(0);
    }

工具类JSONResult:

package com.psy.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;
    }

}
@ResponseBody
    @RequestMapping("/jsonData3")
    public JSONResult jsonData3(){
        Map map = new HashMap();

        return JSONResult.ok("成功:这里可以存放字符串、对象、数组、集合都行,这样可以节省拼接map集合的过程");
    }

    @ResponseBody
    @RequestMapping("/jsonData4")
    public JSONResult jsonData4(){
        return JSONResult.errorMsg("失败:这里可以存放字符串、对象、数组、集合都行,这样可以节省拼接map集合的过程");
    }

原文地址:https://www.cnblogs.com/psyu/p/11610234.html