javaWeb上傳下載下傳檔案

JavaWeb上傳下載下傳案例

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2種方式的上傳下載下傳檔案案例,要導入jsmartcom_zh_CN

目錄清單

定義清單

Markdown　Extra　定義清單文法： 項目１ 項目２

定義 A

定義 B

項目３

定義 C

定義 D

定義D内容

代碼塊

批量下載下傳BatchDownloadServlet

package com.demo.servlet;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class BatchDownloadServlet extends HttpServlet {

    public void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doPost(req,resp);
    }

    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        resp.setContentType("application/x-msdownload");
        resp.setHeader("Content-Disposition", "attachment;filename=test.zip");
        String path = getServletContext().getRealPath("/") + "images/";
        String[] filenames  = req.getParameterValues("filename");
        String str = "";
        String rt = "\r\n";
        ZipOutputStream zos = new ZipOutputStream(resp.getOutputStream());
        for(String filename : filenames){
            str += filename + rt;
            File file = new File(path + filename);
            zos.putNextEntry(new ZipEntry(filename));
            FileInputStream fis = new FileInputStream(file);
            byte b[] = new byte[];
            int n = ;
            while((n = fis.read(b)) != -){
                zos.write(b, , n);
            }
            zos.flush();
            fis.close();
        }
        zos.setComment("download success:" + rt + str);
        zos.flush();
        zos.close();

    }

}
           

檔案下載下傳DownloadServlet

package com.demo.servlet;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DownloadServlet extends HttpServlet {

    public void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        //擷取檔案下載下傳路徑
        String path = getServletContext().getRealPath("/") + "images/";
        String filename = req.getParameter("filename");
        File file = new File(path + filename);
        if(file.exists()){
            //設定相應類型application/octet-stream
            resp.setContentType("application/x-msdownload");
            //設定頭資訊
            resp.setHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
            InputStream inputStream = new FileInputStream(file);
            ServletOutputStream ouputStream = resp.getOutputStream();
            byte b[] = new byte[];
            int n ;
            while((n = inputStream.read(b)) != -){
                ouputStream.write(b,,n);
            }
            //關閉流、釋放資源
            ouputStream.close();
            inputStream.close();


        }else{
            req.setAttribute("errorResult", "檔案不存在下載下傳失敗！");
            RequestDispatcher dispatcher = req.getRequestDispatcher("jsp/01.jsp");
            dispatcher.forward(req, resp);
        }


    }

    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doGet(req,resp);
    }

}
           

簡易下載下傳

package com.demo.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jspsmart.upload.SmartUpload;
import com.jspsmart.upload.SmartUploadException;

public class SmartDownloadServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request,response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String filename = request.getParameter("filename");

        SmartUpload su = new SmartUpload();
        su.initialize(getServletConfig(), request, response);
        su.setContentDisposition(null);
        try {
            su.downloadFile("/images/"+ filename);
        } catch (SmartUploadException e) {
            e.printStackTrace();
        }
    }

}
           

package com.demo.servlet;

import java.io.File;
import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jspsmart.upload.SmartUpload;

public class SmartUploadServlet extends HttpServlet {

    public void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doPost(req,resp);
    }

    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        //設定上傳檔案儲存路徑
        String filePath = getServletContext().getRealPath("/") + "images";
        File file = new File(filePath);
        if(!file.exists()){
            file.mkdir();
        }

        SmartUpload su = new SmartUpload();
        //初始化對象
        su.initialize(getServletConfig(), req, resp);
        //設定上傳檔案大小
        su.setMaxFileSize(**);
        //設定所有檔案的大小
        su.setTotalMaxFileSize(**);
        //設定允許上傳檔案類型
        su.setAllowedFilesList("txt,jpg,gif");
        String result = "上傳成功！";

        try {
            //設定禁止上傳的檔案類型
            su.setDeniedFilesList("rar,jsp,js");
            //上傳檔案
            su.upload();

            int count = su.save(filePath);
            System.out.println("上傳成功" +  count + "個檔案！");
        } catch (Exception e) {
            result = "上傳失敗！";
            e.printStackTrace();
        }

        for(int i =; i < su.getFiles().getCount(); i++){
            com.jspsmart.upload.File tempFile = su.getFiles().getFile(i);
            System.out.println("---------------------------");
            System.out.println("表單當中name屬性值：" + tempFile.getFieldName());
            System.out.println("上傳檔案名：" + tempFile.getFieldName());
            System.out.println("上傳檔案長度:" + tempFile.getSize());
            System.out.println("上傳檔案的拓展名：" + tempFile.getFileExt());
            System.out.println("上傳檔案的全名：" + tempFile.getFilePathName());
            System.out.println("---------------------------");
        }

        req.setAttribute("result", result);
        req.getRequestDispatcher("jsp/02.jsp").forward(req, resp);
    }

}
           

上傳檔案

package com.demo.servlet;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class UploadServlet extends HttpServlet {

    public void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doPost(req,resp);
    }

    public void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        //從request當中擷取流資訊
        InputStream fileSource = req.getInputStream();
        String tempFileName = "E:/tempFile";
        //tempFile指向臨時檔案
        File tempFile = new File(tempFileName);
        //outputStram檔案輸出流指向這個臨時檔案
        FileOutputStream outputStream = new FileOutputStream(tempFile);
        byte b[] = new byte[];
        int n;
        while(( n = fileSource.read(b)) != -){
            outputStream.write(b, , n);
        }
        //關閉輸出流、輸入流
        outputStream.close();
        fileSource.close();

        //擷取上傳檔案的名稱
        RandomAccessFile randomFile = new RandomAccessFile(tempFile,"r");
        randomFile.readLine();
        String str = randomFile.readLine();
        int beginIndex = str.lastIndexOf("\\") + ;
        int endIndex = str.lastIndexOf("\"");
        String filename = str.substring(beginIndex, endIndex);
        System.out.println("filename:" + filename);

        //重新定位檔案指針到檔案頭
        randomFile.seek();
        long startPosition = ;
        int i = ;
        //擷取檔案内容 開始位置
        while(( n = randomFile.readByte()) != - && i <=){
            if(n == '\n'){
                startPosition = randomFile.getFilePointer();
                i ++;
            }
        }
        startPosition = randomFile.getFilePointer() -;
        //擷取檔案内容 結束位置
        randomFile.seek(randomFile.length());
        long endPosition = randomFile.getFilePointer();
        int j = ;
        while(endPosition >= && j<=){
            endPosition--;
            randomFile.seek(endPosition);
            if(randomFile.readByte() == '\n'){
                j++;
            }
        }
        endPosition = endPosition -;

        //設定儲存上傳檔案的路徑
        String realPath = getServletContext().getRealPath("/") + "images";
        File fileupload = new File(realPath);
        if(!fileupload.exists()){
            fileupload.mkdir();
        }
        File saveFile = new File(realPath,filename);
        RandomAccessFile randomAccessFile = new RandomAccessFile(saveFile,"rw");
        //從臨時檔案當中讀取檔案内容（根據起止位置擷取）
        randomFile.seek(startPosition);
        while(startPosition < endPosition){
            randomAccessFile.write(randomFile.readByte());
            startPosition = randomFile.getFilePointer();
        }
        //關閉輸入輸出流、删除臨時檔案
        randomAccessFile.close();
        randomFile.close();
        tempFile.delete();

        req.setAttribute("result", "上傳成功！");
        RequestDispatcher dispatcher = req.getRequestDispatcher("jsp/01.jsp");
        dispatcher.forward(req, resp);
    }
}
           

生成目錄：

• JavaWeb上傳下載下傳案例
  • • 定義清單
    • 代碼塊