Java 下載文件

public @ResponseBody void exportExcel(HttpServletRequest request, HttpServletResponse response, KhxxCxVO vo) throws IOException{
        File csvFile = createCSVFile(request,vo);//獲取要下載的文件

        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;

        response.setHeader("Content-disposition", "attachment; filename=" + URLEncoder.encode(csvFile.getName(), "UTF-8"));

        response.setHeader("Content-Length", String.valueOf(csvFile.length()));

        bis = new BufferedInputStream(new FileInputStream(csvFile));
        bos = new BufferedOutputStream(response.getOutputStream());
        byte[] buff = new byte[2048];
        while (true) {
          int bytesRead;
          if (-1 == (bytesRead = bis.read(buff, 0, buff.length))) break;
          bos.write(buff, 0, bytesRead);
        }
        bis.close();
        bos.close();
    }

 

經常遇到選擇多個文件進行批量下載的情況，可以先將選擇的所有的文件生成一個zip文件，然后再下載，該zip文件，即可實現批量下載，但是在打包過程 中，常常也會出現下載過來的zip文件中里面有亂碼的文件名，通過使用ant.jar中的org.apache.tools.zip里的 ZipOutPutStream為實現編碼的設置。
代碼如下：
ant包引用

<dependency>  
  <groupId>ant</groupId>  
  <artifactId>ant</artifactId>  
  <version>1.6.5</version>  
</dependency>  

壓縮下載的action代碼

    package demo.action;  
      
    import java.io.BufferedInputStream;  
    import java.io.BufferedOutputStream;  
    import java.io.File;  
    import java.io.FileInputStream;  
    import java.io.FileOutputStream;  
    import java.io.IOException;  
    import java.io.InputStream;  
    import java.io.OutputStream;  
    import java.net.URLEncoder;  
      
    import javax.servlet.http.HttpServletResponse;  
      
    import org.apache.log4j.Logger;  
    import org.apache.struts2.ServletActionContext;  
    import org.apache.tools.zip.ZipEntry;  
    import org.apache.tools.zip.ZipOutputStream;  
      
    import com.opensymphony.xwork2.ActionSupport;  
      
    /** 
     * 批量下載文件： 
     *   使用ant.jar包中的org.apache.tools.zip.*完成壓縮， 
     * java原生也有java.util.zip.*但是測試了下無法搞定壓縮 
     * 文件內文件名的中文問題   
     * @author yangcong 
     *  
     */  
    public class BatchDownloadAction extends ActionSupport {  
      
        private Logger Log = Logger.getLogger(BatchDownloadAction.class);  
        private static final String FilePath = "D:\\";  
      
        private static final long serialVersionUID = -8694640030455344419L;  
      
        public String execute() {  
            //生成的ZIP文件名為Demo.zip  
            String tmpFileName = "Demo.zip";  
            byte[] buffer = new byte[1024];  
            String strZipPath = FilePath + tmpFileName;  
            try {  
                ZipOutputStream out = new ZipOutputStream(new FileOutputStream(  
                        strZipPath));  
                // 需要同時下載的兩個文件result.txt ，source.txt  
                File[] file1 = { new File(FilePath+"test1.txt"),  
                        new File(FilePath+"測試2.docx") };  
                for (int i = 0; i < file1.length; i++) {  
                    FileInputStream fis = new FileInputStream(file1[i]);  
                    out.putNextEntry(new ZipEntry(file1[i].getName()));  
                    //設置壓縮文件內的字符編碼，不然會變成亂碼  
                    out.setEncoding("GBK");  
                    int len;  
                    // 讀入需要下載的文件的內容，打包到zip文件  
                    while ((len = fis.read(buffer)) > 0) {  
                        out.write(buffer, 0, len);  
                    }  
                    out.closeEntry();  
                    fis.close();  
                }  
                out.close();  
                this.downFile(getResponse(), tmpFileName);  
            } catch (Exception e) {  
                Log.error("文件下載出錯", e);  
            }  
            return null;  
        }  
      
        /** 
         * 獲取Response 
         * @return 
         */  
        private HttpServletResponse getResponse() {  
            return ServletActionContext.getResponse();  
        }  
      
        /** 
         * 文件下載 
         * @param response 
         * @param str 
         */  
        private void downFile(HttpServletResponse response, String str) {  
            try {  
                String path = FilePath + str;  
                File file = new File(path);  
                if (file.exists()) {  
                    InputStream ins = new FileInputStream(path);  
                    BufferedInputStream bins = new BufferedInputStream(ins);// 放到緩沖流里面  
                    OutputStream outs = response.getOutputStream();// 獲取文件輸出IO流  
                    BufferedOutputStream bouts = new BufferedOutputStream(outs);  
                    response.setContentType("application/x-download");// 設置response內容的類型  
                    response.setHeader(  
                            "Content-disposition",  
                            "attachment;filename="  
                                    + URLEncoder.encode(str, "UTF-8"));// 設置頭部信息  
                    int bytesRead = 0;  
                    byte[] buffer = new byte[8192];  
                    // 開始向網絡傳輸文件流  
                    while ((bytesRead = bins.read(buffer, 0, 8192)) != -1) {  
                        bouts.write(buffer, 0, bytesRead);  
                    }  
                    bouts.flush();// 這里一定要調用flush()方法  
                    ins.close();  
                    bins.close();  
                    outs.close();  
                    bouts.close();  
                } else {  
                    response.sendRedirect("../error.jsp");  
                }  
            } catch (IOException e) {  
                Log.error("文件下載出錯", e);  
            }  
        }  
    }  

  經過在windows環境下測試通過，使用struts2

• ant-1.6.5.jar (1009.8 KB)