com.navjagpal.fileshare.StreamingZipEntity.java Source code

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Here is the source code for com.navjagpal.fileshare.StreamingZipEntity.java

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//   Copyright 2009 Google Inc.
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

package com.navjagpal.fileshare;

import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;

import org.apache.http.entity.AbstractHttpEntity;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * HttpEntity that streams the contents of a shared folder as a ZIP file.
 * 
 * @author nav@gmail.com (Nav Jagpal)
 */
public class StreamingZipEntity extends AbstractHttpEntity {

    private ContentResolver mContentResolver;
    private String mFolderId;
    private boolean mFinished;
    private static final int BUFFER_SIZE = 1024;

    public StreamingZipEntity(ContentResolver contentResolver, String folderId) {
        mContentResolver = contentResolver;
        mFolderId = folderId;
        mFinished = false;
    }

    public InputStream getContent() throws IOException, IllegalStateException {
        PipedInputStream in = new PipedInputStream();
        final PipedOutputStream out = new PipedOutputStream(in);
        new Thread(new Runnable() {
            public void run() {
                try {
                    writeTo(out);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
        return in;
    }

    public long getContentLength() {
        return -1;
    }

    public boolean isRepeatable() {
        return false;
    }

    public boolean isStreaming() {
        return mFinished;
    }

    @Override
    public void consumeContent() {
        mFinished = true;
    }

    public void writeTo(OutputStream out) throws IOException {
        Cursor c = mContentResolver.query(FileSharingProvider.Files.CONTENT_URI,
                new String[] { FileSharingProvider.Files.Columns.DISPLAY_NAME,
                        FileSharingProvider.Files.Columns._DATA },
                FileSharingProvider.Files.Columns.FOLDER_ID + "=?", new String[] { mFolderId }, null);
        ZipOutputStream zipOut = new ZipOutputStream(out);
        byte[] buf = new byte[BUFFER_SIZE];
        while (c.moveToNext()) {
            String filename = c.getString(c.getColumnIndex(FileSharingProvider.Files.Columns.DISPLAY_NAME));
            String data = c.getString(c.getColumnIndex(FileSharingProvider.Files.Columns._DATA));
            zipOut.putNextEntry(new ZipEntry(filename));
            InputStream input = mContentResolver.openInputStream(Uri.parse(data));
            int len;
            while ((len = input.read(buf)) > 0) {
                zipOut.write(buf, 0, len);
            }
            zipOut.closeEntry();
            input.close();
        }
        zipOut.finish();
        mFinished = true;
    }
}