Merge pull request #26 from jiaxun1990/master

 jiaxun1990
upload week03 download commit

group26/89460886/src/week03/source/download/DownloadThread.java

@@ -0,0 +1,40 @@
+package coding.coderising.download;
+
+import coding.coderising.download.api.Connection;
+
+import java.io.IOException;
+
+/**
+ * @author jiaxun
+ */
+public class DownloadThread extends Thread{
+
+    private Connection connection;
+    private int startPos;
+    private int endPos;
+    private byte[] downloadByte;
+
+    public DownloadThread(Connection connection, int startPos, int endPos) {
+        this.connection = connection;
+        this.startPos = startPos;
+        this.endPos = endPos;
+    }
+
+    @Override
+    public void run() {
+        try {
+            downloadByte = connection.read(startPos, endPos);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public byte[] getDownloadByte() {
+        return downloadByte;
+    }
+
+    public int getStartPos() {
+        return startPos;
+    }
+
+}

group26/89460886/src/week03/source/download/FileDownloader.java

@@ -0,0 +1,101 @@
+package coding.coderising.download;
+
+import coding.coderising.download.api.Connection;
+import coding.coderising.download.api.ConnectionManager;
+import coding.coderising.download.api.DownloadListener;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author jiaxun
+ */
+public class FileDownloader {
+
+    private static final int THREAD_COUNT = 3;
+
+    private int threadCount;
+    private String downloadUrl;
+    private DownloadListener downloadListener;
+    private ConnectionManager connectionManager;
+    private String savePath;
+
+    public FileDownloader(String downloadUrl, String savePath) {
+        this.downloadUrl = downloadUrl;
+        this.savePath = savePath;
+        this.threadCount = THREAD_COUNT;
+    }
+
+    public void execute() {
+        Connection connection = null;
+        RandomAccessFile out = null;
+        try {
+            connection = connectionManager.open(downloadUrl);
+            int length = connection.getContentLength();
+            connection.close();
+
+            int downloadOffset = 0;
+            List<DownloadThread> threadList = new ArrayList<>();
+            for (int i = 0; i < threadCount; i++) {
+                DownloadThread thread = new DownloadThread(connectionManager.open(downloadUrl), downloadOffset, downloadOffset + (i + 1) * (length / threadCount));
+                threadList.add(thread);
+                thread.start();
+                downloadOffset = (i + 1) * (length / threadCount) + 1;
+            }
+            if (downloadOffset < length) {
+                DownloadThread thread = new DownloadThread(connectionManager.open(downloadUrl), downloadOffset, length - 1);
+                threadList.add(thread);
+                thread.start();
+            }
+
+            for (DownloadThread thread : threadList) {
+                thread.join();
+            }
+
+            File file = new File(savePath);
+            out = new RandomAccessFile(file, "rwd");
+            for (DownloadThread thread : threadList) {
+                out.seek(thread.getStartPos());
+                out.write(thread.getDownloadByte());
+            }
+
+            if (downloadListener != null) {
+                downloadListener.notifyFinished();
+            }
+
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            if (connection != null) {
+                connection.close();
+            }
+            try {
+                if (out != null) {
+                    out.close();
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    public void setConnectionManager(ConnectionManager connectionManager) {
+        this.connectionManager = connectionManager;
+    }
+
+    public void setDownloadListener(DownloadListener downloadListener) {
+        this.downloadListener = downloadListener;
+    }
+
+    public DownloadListener getDownloadListener() {
+        return this.downloadListener;
+    }
+
+    public void setThreadCount(int threadCount) {
+        this.threadCount = threadCount;
+    }
+
+}

group26/89460886/src/week03/source/download/api/Connection.java

@@ -0,0 +1,16 @@
+package coding.coderising.download.api;
+
+import java.io.IOException;
+
+/**
+ * @author jiaxun
+ */
+public interface Connection {
+
+    byte[] read(int startPos, int endPos) throws IOException;
+
+    int getContentLength();
+
+    void close();
+
+}

group26/89460886/src/week03/source/download/api/ConnectionException.java

@@ -0,0 +1,10 @@
+package coding.coderising.download.api;
+
+/**
+ * @author jiaxun
+ */
+public class ConnectionException extends Exception {
+
+
+
+}

group26/89460886/src/week03/source/download/api/ConnectionManager.java

@@ -0,0 +1,10 @@
+package coding.coderising.download.api;
+
+/**
+ * @author jiaxun
+ */
+public interface ConnectionManager {
+
+    Connection open(String url) throws ConnectionException;
+
+}

group26/89460886/src/week03/source/download/api/DownloadListener.java

@@ -0,0 +1,10 @@
+package coding.coderising.download.api;
+
+/**
+ * @author jiaxun
+ */
+public interface DownloadListener {
+
+    void notifyFinished();
+
+}

group26/89460886/src/week03/source/download/impl/ConnectionImpl.java

@@ -0,0 +1,43 @@
+package coding.coderising.download.impl;
+
+import coding.coderising.download.api.Connection;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+
+/**
+ * @author jiaxun
+ */
+public class ConnectionImpl implements Connection {
+
+    private HttpURLConnection urlConnection;
+
+    public ConnectionImpl(HttpURLConnection urlConnection) {
+        this.urlConnection = urlConnection;
+    }
+
+    @Override
+    public byte[] read(int startPos, int endPos) throws IOException {
+        urlConnection.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);
+        InputStream input = urlConnection.getInputStream();
+        ByteArrayOutputStream output = new ByteArrayOutputStream();
+        int length;
+        byte[] byteArray = new byte[1024];
+        while ((length = input.read(byteArray)) != -1) {
+            output.write(byteArray, 0, length);
+        }
+        return output.toByteArray();
+    }
+
+    @Override
+    public int getContentLength() {
+        return urlConnection.getContentLength();
+    }
+
+    @Override
+    public void close() {
+        urlConnection.disconnect();
+    }
+}

group26/89460886/src/week03/source/download/impl/ConnectionManagerImpl.java

@@ -0,0 +1,27 @@
+package coding.coderising.download.impl;
+
+import coding.coderising.download.api.Connection;
+import coding.coderising.download.api.ConnectionException;
+import coding.coderising.download.api.ConnectionManager;
+
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+/**
+ * @author jiaxun
+ */
+public class ConnectionManagerImpl implements ConnectionManager {
+
+    @Override
+    public Connection open(String urlString) throws ConnectionException {
+
+        try {
+            URL url = new URL(urlString);
+            return new ConnectionImpl((HttpURLConnection) url.openConnection());
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+}