springmvc 文件上传和对json的支持_springmvc application json可以上传文件-优快云博客

本文链接：https://blog.youkuaiyun.com/linyaodonga/article/details/103227163

本文介绍如何在SpringMVC中实现文件上传功能，包括添加依赖、配置解析器及控制器方法。同时，展示了JSON响应的多种方式，如直接返回Map、List或字符串。

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一、文件上传

添加文件上传相关依赖

<commons-fileupload.version>1.3.3</commons-fileupload.version>
 <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>${commons-fileupload.version}</version>
    </dependency>

添加springmvc-servlet.xml里面的配置

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <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>

uploa.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>文件上传</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/book/upload" method="post" enctype="multipart/form-data">
    上传文件：<<input type="file" name="file">
    <button type="submit">上传</button>
</form>
</body>
</html>

HelloController

package com.xhh.controller;

import com.xhh.service.BookService;
import com.xhh.util.JSONResult;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Map;

/**
 * @author 林耀东
 * @site www.baidu.com
 * @company
 * @create 2019-11-24 18：50
 */

/**
 * 五种返回形式
 * 1，转发到jsp界面
 * 2, 转发到Action界面
 * 3, 重定向到jsp界面
 * 4, 重定向到Action界面
 */

@RequestMapping("/hello")
@Controller
public class HelloController {

    @Autowired
    private  BookService bookService;   

    /**
     * 重定向到jsp界面
     * @param request
     * @return
     */
    @RequestMapping("/hello3")
    public String hello3(HttpServletRequest request){
        request.setAttribute("msg","调用了重定向方法到jsp页面");
        return "redirect:/hello.jsp";
    }

    @RequestMapping("/upload")
    public String upload(HttpServletRequest request, MultipartFile img){
        try {
            FileUtils.copyInputStreamToFile(img.getInputStream(),new File("D://imgs//"+img.getOriginalFilename()));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "redirect:hello3";
    }
}

二、josn

package com.xhh.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;
	}
}

BookController

package com.xhh.ssm.controller;

import com.xhh.ssm.model.Book;
import com.xhh.ssm.service.BookService;
import com.xhh.ssm.utils.PageBean;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


@Controller
@RequestMapping("/book")  
public class BookController {
    @Autowired
    private BookService bookService;

    /*  josn */
    @ResponseBody
    @RequestMapping("/json1")
     public Map json1(Book book,HttpServletRequest request){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        List<Map> list = this.bookService.listPager(book, pageBean);
        Map map = new HashMap();
        map.put("total",pageBean.getTotal());
        map.put("data",list);
        return map;
     }
    @ResponseBody
    @RequestMapping("/json2")
    public  List<Map> json2(Book book,HttpServletRequest request){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        List<Map> list = this.bookService.listPager(book, pageBean);
        return list;
    }

    @ResponseBody
    @RequestMapping("/json3")
    public  String json3(Book book,HttpServletRequest request){

        return "springmvc string to josn";
    }

}