SpringMVC檔案上傳和下載下傳

上傳

1. 導入依賴

<!--檔案上傳-->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.3</version>
</dependency>
           

1. 寫一個上傳的頁面

<form action="" enctype="multipart/form-data" method="post">
    <input type="file" name="file"/>
    <input type="submit">
</form>
           

1. 配置bean：multipartResolver

<!--檔案上傳配置-->
<bean id="multipartResolver"  class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 請求的編碼格式，必須和jSP的pageEncoding屬性一緻，以便正确讀取表單的内容，預設為ISO-8859-1 -->
    <property name="defaultEncoding" value="utf-8"/>
    <!-- 上傳檔案大小上限，機關為位元組（10485760=10M） -->
    <property name="maxUploadSize" value="10485760"/>
    <property name="maxInMemorySize" value="40960"/>
</bean>
           

1. 寫一個Controller

package controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@Controller
public class FileController {
	//@RequestParam("file") 将name=file控件得到的檔案封裝成CommonsMultipartFile 對象
	//批量上傳CommonsMultipartFile則為數組即可
	@RequestMapping("/upload")
	public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException {
		//擷取檔案名 : file.getOriginalFilename();
		String uploadFileName = file.getOriginalFilename();
		//如果檔案名為空，直接回到首頁！
		if ("".equals(uploadFileName)){
			return "redirect:/index.jsp";
		}
		System.out.println("上傳檔案名 : "+uploadFileName);
		//上傳路徑儲存設定
		String path = request.getServletContext().getRealPath("/upload");
		//如果路徑不存在，建立一個
		File realPath = new File(path);
		if (!realPath.exists()){
			realPath.mkdir();
		}
		System.out.println("上傳檔案儲存位址："+realPath);
		InputStream is = file.getInputStream(); //檔案輸入流
		OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //檔案輸出流
		//讀取寫出
		int len=0;
		byte[] buffer = new byte[1024];
		while ((len=is.read(buffer))!=-1){
			os.write(buffer,0,len);
			os.flush();
		}
		os.close();
		is.close();
		return "redirect:/index.jsp";
	}
	/*
	 * 采用file.Transto 來儲存上傳的檔案
	 */
	@RequestMapping("/upload2")
	public String  fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
		//上傳路徑儲存設定
		String path = request.getServletContext().getRealPath("/upload");
		File realPath = new File(path);
		if (!realPath.exists()){
			realPath.mkdir();
		}
		//上傳檔案位址
		System.out.println("上傳檔案儲存位址："+realPath);
		//通過CommonsMultipartFile的方法直接寫檔案（注意這個時候）
		file.transferTo(new File(realPath +"/"+ file.getOriginalFilename()));
		return "redirect:/index.jsp";
	}
}
           

下載下傳

頁面

<a href="/download">點選下載下傳</a>
           

controller

//下載下傳
	@RequestMapping(value="/download")
	public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
		//要下載下傳的圖檔位址
		String  path = request.getServletContext().getRealPath("/upload");
		String  fileName = "1632824890.jpg";
		//1、設定response 響應頭
		response.reset(); //設定頁面不緩存,清空buffer
		response.setCharacterEncoding("UTF-8"); //字元編碼
		response.setContentType("multipart/form-data"); //二進制傳輸資料
		//設定響應頭
		response.setHeader("Content-Disposition",
				"attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));
		File file = new File(path,fileName);
		//2、 讀取檔案--輸入流
		InputStream input=new FileInputStream(file);
		//3、 寫出檔案--輸出流
		OutputStream out = response.getOutputStream();
		byte[] buff =new byte[1024];
		int index=0;
		//4、執行 寫出操作
		while((index= input.read(buff))!= -1){
			out.write(buff, 0, index);
			out.flush();
		}
		out.close();
		input.close();
		return "ok";
	}