some questions(continue)

Question

3. download.jsp:
<%
response.reset();
response.setContentType("application/msexcel");
OutputStream os = response.getOutputStream();
response.setHeader("Content-disposition","attachment; filename=courseware.xls");
byte[] bytes = ...
os.write(bytes);
os.close();
%>

Answer 1

response.setContentType("application/msdownload");

Answer 2

download is okay now
now only left :
ow to easily zip a directory

Answer 3

3.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.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;public class FileZip
{
static final char SEPARATOR = File.separatorChar;
private int preffixLen = 0; public void compress(OutputStream out, File file) throws IOException
{
preffixLen = file.getParentFile().getAbsolutePath().length() + 1;
ZipOutputStream zos = new ZipOutputStream(out);
addFile(zos, file);
zos.close();
} private void addFile(ZipOutputStream zos, File file) throws IOException
{
String entryName = entryName(file);
if (entryName.equals("") || entryName.equals("."))
return; System.out.println("adding " + entryName);
ZipEntry entry = new ZipEntry(entryName);
entry.setTime(file.lastModified());
boolean isDirectory = file.isDirectory();
if (isDirectory)
{
entry.setMethod(0);
entry.setSize(0L);
entry.setCrc(0L);
}
else
entry.setSize(file.length()); zos.putNextEntry(entry);
if (isDirectory)
{
File[] files = file.listFiles();
for(int i=0; i<files.length; i++)
addFile(zos, files[i]);
}
else
{
byte buf[] = new byte[1024];
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
int bytes;
while ((bytes = bis.read(buf, 0, buf.length)) != -1)
zos.write(buf, 0, bytes);
bis.close();
}
zos.closeEntry();
} private String entryName(File file)
{
String entryName = file.getPath();
if (file.isDirectory())
entryName = entryName.endsWith(File.separator) ? entryName : entryName + File.separator;
entryName = entryName.replace(File.separatorChar, '/').substring(preffixLen);
return entryName;
} public static void main(String args[])
{
try
{
FileOutputStream fos = new FileOutputStream("test.zip");
FileZip zip = new FileZip();
zip.compress(new BufferedOutputStream(fos), new File("d:\\test\\jsp")); //compress folder d:\test\jsp
fos.close();
}
catch (Throwable e)
{
e.printStackTrace();
}
}
}

Answer 4

正确。我再来加一段从JSP download 一个目录中的所有文件的代码。已经过测试<%!
 public void doZipDirectory(File d, ZipOutputStream out,String rootDir)throws IOException, IllegalArgumentException {
     // Check that the directory is a directory, and get its contents
     if (!d.isDirectory())throw new IllegalArgumentException("Compress: not a directory: " +d);
     String[] entries = d.list();
     byte[] buffer = new byte[4096];  // Create a buffer for copying
     int bytes_read;      // Loop through all entries in the directory
     for(int i = 0; i < entries.length; i++) {
         File f = new File(d, entries[i]);
         //System.out.println(entries[i]);
         if (f.isDirectory())  {
             doZipDirectory(f, out,rootDir);
         }
         else
         {
              FileInputStream in = new FileInputStream(f); // Stream to read file
              String path=f.getPath();
              String relevantPath=path.substring(path.indexOf(rootDir)+rootDir.length());
              ZipEntry entry = new ZipEntry(relevantPath);  // Make a ZipEntry
              out.putNextEntry(entry);                     // Store entry
              while((bytes_read = in.read(buffer)) != -1)  // Copy bytes
                  out.write(buffer, 0, bytes_read);
              in.close();                                  // Close input stream
         }
      }
 }%>
<%
try{
        //getParameter
     String courseware_ID=PatchUtil.nvl(request.getParameter("courseware_ID"));
     String coursewareName=getCoursewareName(courseware_ID); //find dir
        java.io.File file=new java.io.File("");
        String separator=java.io.File.separator;
        String rootDir=file.getAbsolutePath()+separator+"config"+separator+"nebo"+
          separator+"applications"+separator+"NEBOWEBAPP"+separator+"resource"+separator;
        String strCourseDir=rootDir+"Course_"+coursewareName+separator;
        File courseDir=new java.io.File(strCourseDir);
     if(courseDir.exists() && courseDir.isDirectory());
     else
       courseDir.mkdirs();       //generate zip file
     //download
        response.reset();
     response.setContentType("application/msdownload");
     OutputStream os = response.getOutputStream();
     response.setHeader("Content-disposition","attachment; filename=courseware.zip");        ZipOutputStream zos=new ZipOutputStream(os);
        doZipDirectory(new File(strCourseDir),zos,rootDir);     zos.close();
}
catch(Exception e){
e.printStackTrace();
        //throw new Exception(e);
}
%>