oni2/httpfiledownloader/FileDownloader.java

package net.oni2.httpfiledownloader;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashSet;

/**
 * @author Christian Illy
 */
public class FileDownloader implements Runnable {
        /**
         * @author Christian Illy
         */
        public enum EState {
                /**
                 * Downloader initialized but not started
                 */
                INIT,
                /**
                 * Download running
                 */
                RUNNING,
                /**
                 * Download suspended
                 */
                PAUSED,
                /**
                 * Download interrupted
                 */
                INTERRUPTED,
                /**
                 * Download finished successfully
                 */
                FINISHED,
                /**
                 * Aborted because of an error
                 */
                ERROR
        };

        private HashSet<FileDownloadListener> listeners = new HashSet<FileDownloadListener>();
        private Thread t = null;
        private URL url = null;
        private File target = null;
        private int fileLength = Integer.MAX_VALUE;
        private int downloaded = 0;

        private EState state = EState.INIT;

        /**
         * @param url
         *            URL of file to download
         * @param target
         *            Path of target file to save to
         * @throws IOException
         *             If url could not be opened
         */
        public FileDownloader(String url, File target) throws IOException {
                this.url = new URL(url);
                this.target = target;
        }

        /**
         * @param listener
         *            Listener to add
         */
        public void addListener(FileDownloadListener listener) {
                listeners.add(listener);
        }

        /**
         * @param listener
         *            Listener to remove
         */
        public void removeListener(FileDownloadListener listener) {
                listeners.remove(listener);
        }

        /**
         * Start the download process
         */
        public synchronized void start() {
                if (t == null) {
                        t = new Thread(this);
                        t.start();
                        state = EState.RUNNING;
                }
        }

        /**
         * @param suspend
         *            Suspend or resume
         */
        public synchronized void suspend(boolean suspend) {
                if ((state == EState.RUNNING) || (state == EState.PAUSED)) {
                        if (suspend)
                                state = EState.PAUSED;
                        else
                                state = EState.RUNNING;
                        updateStatus(downloaded, fileLength);
                }
        }

        /**
         * Stop (abort) download
         */
        public synchronized void stop() {
                if (state != EState.FINISHED) {
                        state = EState.INTERRUPTED;
                        if (t != null) {
                                try {
                                        t.join();
                                } catch (InterruptedException e) {
                                        e.printStackTrace();
                                }
                                t = null;
                        }
                        updateStatus(0, 1);
                        if (target.exists())
                                target.delete();
                }
        }

        /**
         * @return current state
         */
        public EState getState() {
                return state;
        }

        private synchronized void updateStatus(int current, int total) {
                downloaded = current;
                for (FileDownloadListener l : listeners) {
                        l.statusUpdate(this, state, current, total);
                }
        }

        @Override
        public void run() {
                int downloaded = 0;
                String strLastModified = null;
                String strEtag = null;
                RandomAccessFile outFile = null;
                try {
                        outFile = new RandomAccessFile(target, "rw");
                } catch (FileNotFoundException e1) {
                        e1.printStackTrace();
                        state = EState.ERROR;
                        updateStatus(downloaded, fileLength);
                        return;
                }

                try {
                        while (downloaded < fileLength) {
                                switch (state) {
                                        case ERROR:
                                                updateStatus(downloaded, fileLength);
                                                return;
                                        case PAUSED:
                                                try {
                                                        Thread.sleep(100);
                                                } catch (InterruptedException e) {
                                                        e.printStackTrace();
                                                }
                                                break;
                                        case INTERRUPTED:
                                                return;
                                        case RUNNING:
                                                BufferedInputStream input = null;
                                                try {
                                                        URLConnection connection = url.openConnection();
                                                        connection.setRequestProperty("Cache-Control", "no-cache");
                                                        if (downloaded == 0) {
                                                                connection.connect();
                                                                strLastModified = connection
                                                                                .getHeaderField("Last-Modified");
                                                                strEtag = connection.getHeaderField("ETag");
                                                                fileLength = connection.getContentLength();
                                                        } else {
                                                                connection.setRequestProperty("Range", "bytes="
                                                                                + downloaded + "-");
                                                                if (strEtag != null)
                                                                        connection.setRequestProperty("If-Range",
                                                                                        strEtag);
                                                                else
                                                                        connection.setRequestProperty("If-Range",
                                                                                        strLastModified);
                                                                connection.connect();
                                                        }

                                                        // Setup streams and buffers.
                                                        input = new BufferedInputStream(
                                                                        connection.getInputStream(), 8192);
                                                        if (downloaded > 0)
                                                                outFile.seek(downloaded);
                                                        byte data[] = new byte[1024];

                                                        // Download file.
                                                        int dataRead = 0;
                                                        int i = 0;
                                                        while (((dataRead = input.read(data, 0, 1024)) != -1)
                                                                        && (state == EState.RUNNING)) {
                                                                outFile.write(data, 0, dataRead);
                                                                downloaded += dataRead;
                                                                if (downloaded >= fileLength)
                                                                        break;

                                                                i++;
                                                                if ((i % 50) == 0)
                                                                        updateStatus(downloaded, fileLength);
                                                        }
                                                        input.close();
                                                } catch (IOException e) {
                                                        // TODO Auto-generated catch block
                                                        e.printStackTrace();
                                                        try {
                                                                if (input != null)
                                                                        input.close();
                                                        } catch (IOException e2) {
                                                                e2.printStackTrace();
                                                        }
                                                }
                                                break;
                                        default:
                                                break;
                                }
                        }
                } finally {
                        try {
                                // Close streams.
                                outFile.close();
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
                }

                state = EState.FINISHED;
                updateStatus(downloaded, fileLength);
        }

        /**
         * @return the target
         */
        public File getTarget() {
                return target;
        }

        /**
         * @return the downloaded size
         */
        public int getDownloaded() {
                return downloaded;
        }

}
Revision:	741
Committed:	Sun Mar 24 16:09:44 2013 UTC (12 years, 7 months ago) by alloc
Content type:	text/x-java
File size:	5517 byte(s)
Log Message:	HTTP File Downloader lib - import
#	Content
1	package net.oni2.httpfiledownloader;
2
3	import java.io.BufferedInputStream;
4	import java.io.File;
5	import java.io.FileNotFoundException;
6	import java.io.IOException;
7	import java.io.RandomAccessFile;
8	import java.net.URL;
9	import java.net.URLConnection;
10	import java.util.HashSet;
11
12	/**
13	* @author Christian Illy
14	*/
15	public class FileDownloader implements Runnable {
16	/**
17	* @author Christian Illy
18	*/
19	public enum EState {
20	/**
21	* Downloader initialized but not started
22	*/
23	INIT,
24	/**
25	* Download running
26	*/
27	RUNNING,
28	/**
29	* Download suspended
30	*/
31	PAUSED,
32	/**
33	* Download interrupted
34	*/
35	INTERRUPTED,
36	/**
37	* Download finished successfully
38	*/
39	FINISHED,
40	/**
41	* Aborted because of an error
42	*/
43	ERROR
44	};
45
46	private HashSet<FileDownloadListener> listeners = new HashSet<FileDownloadListener>();
47	private Thread t = null;
48	private URL url = null;
49	private File target = null;
50	private int fileLength = Integer.MAX_VALUE;
51	private int downloaded = 0;
52
53	private EState state = EState.INIT;
54
55	/**
56	* @param url
57	* URL of file to download
58	* @param target
59	* Path of target file to save to
60	* @throws IOException
61	* If url could not be opened
62	*/
63	public FileDownloader(String url, File target) throws IOException {
64	this.url = new URL(url);
65	this.target = target;
66	}
67
68	/**
69	* @param listener
70	* Listener to add
71	*/
72	public void addListener(FileDownloadListener listener) {
73	listeners.add(listener);
74	}
75
76	/**
77	* @param listener
78	* Listener to remove
79	*/
80	public void removeListener(FileDownloadListener listener) {
81	listeners.remove(listener);
82	}
83
84	/**
85	* Start the download process
86	*/
87	public synchronized void start() {
88	if (t == null) {
89	t = new Thread(this);
90	t.start();
91	state = EState.RUNNING;
92	}
93	}
94
95	/**
96	* @param suspend
97	* Suspend or resume
98	*/
99	public synchronized void suspend(boolean suspend) {
100	if ((state == EState.RUNNING) \|\| (state == EState.PAUSED)) {
101	if (suspend)
102	state = EState.PAUSED;
103	else
104	state = EState.RUNNING;
105	updateStatus(downloaded, fileLength);
106	}
107	}
108
109	/**
110	* Stop (abort) download
111	*/
112	public synchronized void stop() {
113	if (state != EState.FINISHED) {
114	state = EState.INTERRUPTED;
115	if (t != null) {
116	try {
117	t.join();
118	} catch (InterruptedException e) {
119	e.printStackTrace();
120	}
121	t = null;
122	}
123	updateStatus(0, 1);
124	if (target.exists())
125	target.delete();
126	}
127	}
128
129	/**
130	* @return current state
131	*/
132	public EState getState() {
133	return state;
134	}
135
136	private synchronized void updateStatus(int current, int total) {
137	downloaded = current;
138	for (FileDownloadListener l : listeners) {
139	l.statusUpdate(this, state, current, total);
140	}
141	}
142
143	@Override
144	public void run() {
145	int downloaded = 0;
146	String strLastModified = null;
147	String strEtag = null;
148	RandomAccessFile outFile = null;
149	try {
150	outFile = new RandomAccessFile(target, "rw");
151	} catch (FileNotFoundException e1) {
152	e1.printStackTrace();
153	state = EState.ERROR;
154	updateStatus(downloaded, fileLength);
155	return;
156	}
157
158	try {
159	while (downloaded < fileLength) {
160	switch (state) {
161	case ERROR:
162	updateStatus(downloaded, fileLength);
163	return;
164	case PAUSED:
165	try {
166	Thread.sleep(100);
167	} catch (InterruptedException e) {
168	e.printStackTrace();
169	}
170	break;
171	case INTERRUPTED:
172	return;
173	case RUNNING:
174	BufferedInputStream input = null;
175	try {
176	URLConnection connection = url.openConnection();
177	connection.setRequestProperty("Cache-Control", "no-cache");
178	if (downloaded == 0) {
179	connection.connect();
180	strLastModified = connection
181	.getHeaderField("Last-Modified");
182	strEtag = connection.getHeaderField("ETag");
183	fileLength = connection.getContentLength();
184	} else {
185	connection.setRequestProperty("Range", "bytes="
186	+ downloaded + "-");
187	if (strEtag != null)
188	connection.setRequestProperty("If-Range",
189	strEtag);
190	else
191	connection.setRequestProperty("If-Range",
192	strLastModified);
193	connection.connect();
194	}
195
196	// Setup streams and buffers.
197	input = new BufferedInputStream(
198	connection.getInputStream(), 8192);
199	if (downloaded > 0)
200	outFile.seek(downloaded);
201	byte data[] = new byte[1024];
202
203	// Download file.
204	int dataRead = 0;
205	int i = 0;
206	while (((dataRead = input.read(data, 0, 1024)) != -1)
207	&& (state == EState.RUNNING)) {
208	outFile.write(data, 0, dataRead);
209	downloaded += dataRead;
210	if (downloaded >= fileLength)
211	break;
212
213	i++;
214	if ((i % 50) == 0)
215	updateStatus(downloaded, fileLength);
216	}
217	input.close();
218	} catch (IOException e) {
219	// TODO Auto-generated catch block
220	e.printStackTrace();
221	try {
222	if (input != null)
223	input.close();
224	} catch (IOException e2) {
225	e2.printStackTrace();
226	}
227	}
228	break;
229	default:
230	break;
231	}
232	}
233	} finally {
234	try {
235	// Close streams.
236	outFile.close();
237	} catch (IOException e) {
238	e.printStackTrace();
239	}
240	}
241
242	state = EState.FINISHED;
243	updateStatus(downloaded, fileLength);
244	}
245
246	/**
247	* @return the target
248	*/
249	public File getTarget() {
250	return target;
251	}
252
253	/**
254	* @return the downloaded size
255	*/
256	public int getDownloaded() {
257	return downloaded;
258	}
259
260	}