This time I will bring you FormData and Spring MVC to implement the Ajax file downloadfunction. What are theprecautionsfor FormData and Spring MVC to implement the Ajax file download function. The following is a practical case. , let’s take a look.

Ajax file download

Using the FormData object and Spring MVC to implement the Ajax file upload function:

Steps

1. Import components and prepare static scripts

commons-fileupload commons-fileupload 1.3.2

Ajax 文件上载

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1. Bind events to buttons

$("upload").click(ajaxUpload);

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2. Get files

var file1 = $("#file1")[0].files[0]; var file2 = $("#file2")[0].files[0];

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3. Create the form object in memory and add the data transmitted to the server

//创建内存中的表单对象 var form = new FormData(); //向其中添加要传输的数据 form.append("userfile1", file1); form.append("userfile2", file2);

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4.ajax() upload object

$.ajax({ url:'user/upload.do',//请求地址 data: form, //请求参数 type: 'POST', //请求类型 dataType: 'json',//服务器返回的数据类型 contentType: false,//没有设置任何内容类型头信息 processData: false, //见jQuery_api详解 success: function(obj){ //成功时回调函数,obj表示服务器返回的数据 if(obj.state==0){ $('#result').html("成功!"); } } });

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5.Spring-MVC presentation layer

@RequestMapping("/upload.do") @ResponseBody public JsonResult upload( MultipartFile userfile1, MultipartFile userfile2) throws Exception{ //Spring MVC 中可以利用 MultipartFile //接收 上载的文件! 文件中的一切数据 //都可以从 MultipartFile 对象中找到 //获取上再是原始文件名 String file1 = userfile1.getOriginalFilename(); String file2 = userfile2.getOriginalFilename(); System.out.println(file1); System.out.println(file2); //保存文件的3种方法: //1. transferTo(目标文件) // 将文件直接保存到目标文件, 可以处理大文件 //2. userfile1.getBytes() 获取文件的全部数据 // 将文件全部读取到内存, 适合处理小文件!! //3. userfile1.getInputStream() // 获取上载文件的流, 适合处理大文件 //保存的目标文件夹: /home/soft01/demo File dir = new File("D:/demo"); dir.mkdir(); File f1 = new File(dir, file1); File f2 = new File(dir, file2); //第一种保存文件 //userfile1.transferTo(f1); //userfile2.transferTo(f2); //第三种 利用流复制数据 InputStream in1 = userfile1.getInputStream(); FileOutputStream out1 = new FileOutputStream(f1); int b; while((b=in1.read())!=-1){ out1.write(b); } in1.close(); out1.close(); InputStream in2 = userfile2.getInputStream(); FileOutputStream out2= new FileOutputStream(f2); byte[] buf= new byte[8*1024]; int n; while((n=in2.read(buf))!=-1){ out2.write(buf, 0, n); } in2.close(); out2.close(); return new JsonResult(true); }

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!