使用ajax跨域调用springboot框架的api传输文件

在新项目中使用的是springboot编写的api，涉及到ajax跨域请求和传输文件的问题，在这里记录一下
首先是前台页面的代码

!DOCTYPE html
html
 head
  meta charset="utf-8"
  titletest_api/title
  script type="text/javascript" src="jquery-1.7.2.js"/script
  script type="text/javascript"
   function test(){
    var obj = new Object;
    obj.name = $("#name").val();
    obj.age = $("#age").val();
    var file = document.getElementById("file").files[0];
    var formData = new FormData();
    formData.append("data",JSON.stringify(obj));
    formData.append("file",file);
    $.ajax({
     type:"post",
     url:"http://*localho**st:8187/test/upload",
     contentType:false,
     processData:false,
     data:formData,
     success:function(data){
       alert(data.msg);
     }
    });
   }
  /script
 /head
 body
  div class=""
   table
    tr
     tdsCompany:/td
     tdinput type="text" id="name" value="tom" //td
    /tr
    tr
     tdscardtype:/td
     tdinput type="text" id="age" value="23" //td
    /tr
    tr
     tdfile:/td
     tdinput type="file" id="file" //td
    /tr
   /table
   input type="button" onclick="test();" value="提交" /
  /div
 /body
/html

程序入口类的代码

package test;

import javax.servlet.MultipartConfigElement;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

/**
 * Hello world!
 *
 */

@SpringBootApplication
public class App 
{

  public static void main( String[] args )
  {
    SpringApplication.run(App.class, args);
  }
  //设置ajax跨域请求
  @Bean
  public WebMvcConfigurer corsConfigurer(){
    return new WebMvcConfigurerAdapter(){

      @Override
      public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**").allowedOrigins("*");
      }
    };
  }

  @Bean
  public MultipartConfigElement multipartConfigElement(){
    MultipartConfigFactory factory = new MultipartConfigFactory();
    //设置上传文件大小限制
    factory.setMaxFileSize("10MB");
    //设置上传总数据大小
    factory.setMaxRequestSize("15MB");
    return factory.createMultipartConfig();
  }
}

api代码

package test.controller;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import test.model.UploadInfo;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

@RestController
@RequestMapping("/test")
public class TestController {

  /**
   * 上传文件
   * @param req form请求
   * @return json字符串
   */
  @RequestMapping(value="/upload", method=RequestMethod.POST)
  public String uploadFile(HttpServletRequest req){ 
    // 返回结果用 json对象
    JSONObject returnObj = new JSONObject();
    //从请求中获取请求的json字符串
    String strData = req.getParameter("data");
    //将获取到的JSON字符串转换为Imgidx对象
    UploadInfo info = JSON.parseObject(strData, UploadInfo.class);
    //获取上传的文件集合
    ListMultipartFile files = ((MultipartHttpServletRequest)req).getFiles("file");
    MultipartFile file = files.get(0);
    // 返回信息头部
    MapString, String header = new HashMapString, String();
    header.put("code", "0");
    header.put("msg", "success");
    File file1234 = new File(file.getOriginalFilename());
    //插入数据的影响的数据条数
    int result = 0;
    //将文件上传到save
    if(!file.isEmpty()){
      try{
        byte[] arr = new byte[1024];
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file1234));
        bos.write(arr);
        bos.flush();
        bos.close();
      }catch(Exception e){
        header.put("code", "-1");
        header.put("msg", "errorMsg:" + e.getMessage());
      }
    }else{
      header.put("code", "-1");
      header.put("msg", "errorMsg:上传文件失败，因为文件是空的");
    }
    String returnStr = returnObj.toJSONString(header);
    return returnStr;
  }
}