java上传文件(图片),并把文件地址返回给前端

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
 
import com.alibaba.fastjson.JSON;
import com.siyang.CommonUtil.BaseController;
import com.siyang.entity.ResponseResult;
/**
 * 照片上传工具类
 * @author admin
 *
 */
@Controller
@RequestMapping("/business")
public class UploaderController extends BaseController{
    @ResponseBody
    @RequestMapping("/uploadImg.xhtml")
    public void uploadPicture(@RequestParam(value="file",required=false)MultipartFile file,HttpServletRequest request,HttpServletResponse response){
        ResponseResult result = new ResponseResult();
        Map<String, Object> map = new HashMap<String, Object>();
        File targetFile=null;
        String url="";//返回存储路径
        int code=1;
        System.out.println(file);
        String fileName=file.getOriginalFilename();//获取文件名加后缀
        if(fileName!=null&&fileName!=""){   
            String returnUrl = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + request.getContextPath() +"/upload/imgs/";//存储路径
            String path = request.getSession().getServletContext().getRealPath("upload/imgs"); //文件存储位置
            String fileF = fileName.substring(fileName.lastIndexOf("."), fileName.length());//文件后缀
            fileName=new Date().getTime()+"_"+new Random().nextInt(1000)+fileF;//新的文件名
              //先判断文件是否存在
            SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
            String fileAdd = sdf.format(new Date());
            //获取文件夹路径
            File file1 =new File(path+"/"+fileAdd); 
            //如果文件夹不存在则创建    
            if(!file1 .exists()  && !file1 .isDirectory()){       
                file1 .mkdir();  
            }
            //将图片存入文件夹
            targetFile = new File(file1, fileName);
            try {
                //将上传的文件写到服务器上指定的文件。
                file.transferTo(targetFile);
                url=returnUrl+fileAdd+"/"+fileName;
                code=0;
                result.setCode(code);
                result.setMessage("图片上传成功");
                map.put("url", url);
                result.setResult(map);
            } catch (Exception e) {
                e.printStackTrace();
                result.setMessage("系统异常，图片上传失败");
            }
        }
       writeJson(response, result);
    }
}