springmvc图片上传及json数据转换过程详解

2019-11-26 08:30:27

字体：大中小

来源：转载

供稿：网友

springmvc的图片上传

1.导入相应的pom依赖

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

2.添加springmvc-servlet.xml里面的配置

<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.前台文件上传表单

<%-- Created by IntelliJ IDEA. User: ASUS Date: 2019/10/5 Time: 10:25 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">    上传的文件：<input type="file" name="img" id="">    <button type="submit">提交</button>  </form></body></html>

HelloController

/**   * 文件上传   * @param img   * @return   */  @RequestMapping("/upload")  public String upload(MultipartFile img){    try {      FileUtils.copyInputStreamToFile(img.getInputStream(),new File("F:/xxx/"+img.getOriginalFilename()));    } catch (IOException e) {      e.printStackTrace();    }    return "forward:hello3";  }

json数据转换

注解格式转换@ResponseBody

工具类JSONResult

package com.liuwenwu.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;  }}

HelloController

@ResponseBody  @RequestMapping("/jsonData3")  public JSONResult jsonData3(){    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结合的过程");  }  @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结合的过程");  }

效果：