Spring boot 基于ajax 文件上传下载

1.配置静态文件访问路径

@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/images/**").addResourceLocations("classpath:/images/");
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
        registry.addResourceHandler("/view/**").addResourceLocations("classpath:/view/");
        super.addResourceHandlers(registry);
    }
}

2.配置文件上传大小

@Configuration
public class BeanConfig {

    @Bean
    public MultipartConfigElement init(){
        MultipartConfigFactory factory = new MultipartConfigFactory();
        //文件最大
        factory.setMaxFileSize("102400KB"); //KB,MB
        /// 设置总上传数据总大小
        factory.setMaxRequestSize("102400KB");
        return factory.createMultipartConfig();
    }
}

3.多文件上传接口，下载文件接口

import com.example.demo.util.FileUploadUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.*;

@RequestMapping("/file")
@Controller
public class FileCtrl {

    private static final String uploadPath = "D:/Images/";

    @Autowired
    private FileUploadUtil fileUploadUtil;

    @RequestMapping("/images")
    public String uploadTest() {
        return "images";
    }

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    @ResponseBody
    public List<Map<String, Object>> uploadFile(HttpServletRequest request, @RequestParam MultipartFile[] files) {
        return fileUploadUtil.upload(files, uploadPath);
    }

    @RequestMapping("/load")
    public ResponseEntity<byte[]> fileDownLoad(@RequestParam("fileName") String fileName) throws Exception{
        String filePath= uploadPath+fileName;
        InputStream in=new FileInputStream(new File(filePath));
        byte[] body=null;
        body=new byte[in.available()];
        in.read(body);
        fileName=new String(fileName.getBytes("gbk"),"iso8859-1");
        HttpHeaders headers=new HttpHeaders();
        headers.add("Content-Disposition", "attachment;filename="+fileName);
        HttpStatus statusCode = HttpStatus.OK;
        ResponseEntity<byte[]> response=new ResponseEntity<byte[]>(body, headers, statusCode);
        return response;
    }
}

4.文件上传工具类

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.util.*;

@Component
public class  FileUploadUtil{

    public List<Map<String,Object>> upload(MultipartFile[] fileList,String uploadPath) {
        List<Map<String, Object>> list = new ArrayList<>();
        if (fileList != null) {
            for (MultipartFile file : fileList) {
                long fileSize = file.getSize();
                String oriName = file.getOriginalFilename();
                String newName = UUID.randomUUID() + "." + StringUtils.substringAfterLast(oriName, ".");
                try {
                    //method1(file,uploadPath,newName);
                    method2(file,uploadPath,newName);
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new RuntimeException("copyInputStreamToFile error.");
                }
                Map<String, Object> res = new HashMap<>();
                res.put("fileSize", fileSize);
                res.put("oriName", oriName);
                res.put("imageName", newName);
                list.add(res);
            }
        }
        return list;
    }

    //基于spring接口文件保存
    private void method1(MultipartFile file,String path,String fileName) throws IOException {
        File localFile = new File(path);
        if (!localFile.exists()) {
            localFile.mkdir();
        }
        file.transferTo(new File(path, fileName));
    }

    //基于apache文件保存
    private void method2(MultipartFile file,String path,String fileName) throws IOException {
        FileUtils.copyInputStreamToFile(file.getInputStream(), new File(path, fileName));
    }

}

5.文件上传页面

<html lang="zh-CN">
<head>
    <meta charset="UTF-8"/>
    <script src="/static/jquery-1.8.3.min.js"></script>
    <script src="/static/ajaxfileupload.js"></script>
</head>
<body>
    <input id="upload" type="file" name="files" multiple="multiple" value="上传文件" onchange="fileChange()"/>
    <hr/>
    <div id="images">
        <img src=""/>
    </div>
</body>
<script type="text/javascript">
    function fileChange(){
        debugger;
        var fielId= event.target.id;
        $.ajaxFileUpload({
            url:'/file/upload',
            type: 'post',
            secureuri:false,
            fileElementId:fielId,//文件选择框的id属性
            dataType: 'json',   //json
            success: function(res){
                console.log(res);
                $(res).each(function(index,data){
                    var image="<img with='300' height='300' src='/file/load?fileName=";
                    image+= data.imageName;
                    image+= "'/>";
                    $("#images").append(image);
                });
            },
            error:function(XMLHttpRequest, textStatus, errorThrown){
                alert('上传失败！');
            }
        });
    }
</script>
</html>