Merge pull request #38 from kwy126/master

第三次作业，包括针对linklist的数据结构操作，以及多线程下载

group03/58555264/src/main/java/com/circle/download/DownloadThread.java

@@ -0,0 +1,54 @@
+package com.circle.download;
+
+import com.circle.download.api.Connection;
+import com.circle.download.api.ConnectionException;
+import com.circle.download.api.DownloadListener;
+
+import java.io.*;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public class DownloadThread extends Thread {
+
+    private Connection conn;
+    private int startPos;
+    private int endPos;
+    static int threadFinished = 0;
+
+    private DownloadListener listener;
+    private int threadNum;
+
+
+    public DownloadThread(Connection conn, int startPos, int endPos, DownloadListener listener, int threadNum) {
+
+        this.conn = conn;
+        this.startPos = startPos;
+        this.endPos = endPos;
+        this.listener = listener;
+        this.threadNum = threadNum;
+    }
+
+    @Override
+    public void run() {
+        try {
+            this.conn.read(startPos, endPos);
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch (ConnectionException e) {
+            e.printStackTrace();
+        } finally {
+            synchronized (this) {
+                threadFinished++;
+                if (threadFinished == threadNum) {
+                    listener.notifyFinished();
+                }
+
+            }
+
+        }
+        System.out.println("线程：" + Thread.currentThread().getId() + " , startPos:" + startPos + ",endPos:" + endPos);
+
+    }
+}
+

group03/58555264/src/main/java/com/circle/download/FileDownloader.java

@@ -0,0 +1,106 @@
+package com.circle.download;
+
+import com.circle.download.api.Connection;
+import com.circle.download.api.ConnectionException;
+import com.circle.download.api.ConnectionManager;
+import com.circle.download.api.DownloadListener;
+import com.circle.download.impl.ConnectionManagerFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public class FileDownloader {
+    private String url;
+    private DownloadListener listener;
+    private ConnectionManager cm;
+    private int threadNum;
+
+    public FileDownloader(String url, int threadNum) {
+        this.threadNum = threadNum;
+        this.url = url;
+    }
+
+    public DownloadListener getListener() {
+        return listener;
+    }
+
+    public void setListener(DownloadListener listener) {
+        this.listener = listener;
+    }
+
+    /**
+     * 具体的实现思路：
+     * 1、需要调用ConnectionManager的open方法打开连接，然后通过Connection.getConnection.getContentLength方法获得文件的长度
+     * 2、至少启动3个线程下载，注意每个线程需要调用ConnectionManager的open方法
+     * 然后调用read方法，read方法中有读取文件的开始位置和结束位置的参数，返回值是byte[]数组
+     * 3、把byte数组写入到文件中
+     * 4、所有的线程都下载完成以后，需要调用listener的notifiedFinished方法
+     */
+    public void execute() {
+        Connection conn = null;
+        int[] startPos = new int[threadNum];
+        int[] endPos = new int[threadNum];
+        RandomAccessFile raf = null;
+
+        try {
+            String[] ss = url.split("/");
+            Thread[] threads = new Thread[threadNum];
+
+            File file = new File(ss[ss.length - 1]);
+
+
+            cm = ConnectionManagerFactory.getManager(file);
+            conn = cm.open(this.url);
+            int length = conn.getContentLength();
+            System.out.println("length:" + length);
+
+
+            raf = new RandomAccessFile(file, "rwd");
+            raf.setLength(length);
+
+            for (int i = 0; i < threadNum; i++) {
+                int size = i * (length / threadNum);
+                startPos[i] = size;
+
+                if (i == threadNum - 1) {
+                    endPos[i] = length;
+                } else {
+                    size = (i + 1) * (length / threadNum);
+                    endPos[i] = size - 1;
+                }
+
+                threads[i] = new DownloadThread(cm.open(this.url), startPos[i], endPos[i],listener,threadNum);
+                threads[i].start();
+            }
+        } catch (ConnectionException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+            if (raf != null) {
+                try {
+                    raf.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        String url2 = "http://hiphotos.baidu.com/240728057/pic/item/6a50e38242aad8f60cf4d2b3.jpg";
+        String url = "http://bcbang.oss-cn-qingdao.aliyuncs.com/TLAB-in-Eden-memory.png";
+        String url3 = "http://www.cnblogs.com/iwideal/p/6045118.html";
+        FileDownloader downloader = new FileDownloader(url2, 2);
+        downloader.execute();
+
+    }
+
+}

group03/58555264/src/main/java/com/circle/download/api/Connection.java

@@ -0,0 +1,31 @@
+package com.circle.download.api;
+
+import java.io.IOException;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public interface Connection {
+
+    /**
+     * 给定开始和结束位置，读取数据，返回值是字节数组
+     *
+     * @param startPos 开始位置，从0开始
+     * @param endPos   结束位置
+     * @return
+     * @throws IOException
+     */
+    public void read(int startPos, int endPos) throws IOException, ConnectionException;
+
+    /**
+     * 得到数据内容的长度
+     * @return
+     */
+    public int getContentLength();
+
+    /**
+     * 关闭连接
+     */
+    public void close();
+
+}

group03/58555264/src/main/java/com/circle/download/api/ConnectionException.java

@@ -0,0 +1,24 @@
+package com.circle.download.api;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public class ConnectionException extends Exception {
+
+    public ConnectionException() {
+
+    }
+
+    /**
+     * 描述异常
+     * @param msg
+     */
+    public ConnectionException(String msg) {
+        super(msg);
+
+    }
+}
+
+
+
+

group03/58555264/src/main/java/com/circle/download/api/ConnectionManager.java

@@ -0,0 +1,12 @@
+package com.circle.download.api;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.sql.*;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public interface ConnectionManager {
+    public Connection open(String url) throws ConnectionException, IOException;
+}

group03/58555264/src/main/java/com/circle/download/api/DownloadListener.java

@@ -0,0 +1,8 @@
+package com.circle.download.api;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+public interface DownloadListener {
+    public void notifyFinished();
+}

group03/58555264/src/main/java/com/circle/download/impl/ConnectionImpl.java

@@ -0,0 +1,77 @@
+package com.circle.download.impl;
+
+import com.circle.download.api.Connection;
+import com.circle.download.api.ConnectionException;
+
+import java.io.*;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+class ConnectionImpl implements Connection {
+    private String url;
+    private HttpURLConnection conn;
+    private File file;
+
+    public ConnectionImpl(String url, File file) throws IOException, ConnectionException {
+        this.file = file;
+        this.url = url;
+        this.conn = init();
+    }
+
+    private HttpURLConnection init() throws IOException, ConnectionException {
+        URL httpURL = new URL(url);
+        this.conn = (HttpURLConnection) httpURL.openConnection();
+
+        this.conn.setRequestMethod("GET");
+        this.conn.setRequestProperty("Charset", "UTF-8");
+        return conn;
+    }
+
+    @Override
+    public void read(int startPos, int endPos) throws IOException, ConnectionException {
+        URL httpURL = new URL(url);
+        this.conn = (HttpURLConnection) httpURL.openConnection();
+
+        this.conn.setRequestMethod("GET");
+        this.conn.setRequestProperty("Charset", "UTF-8");
+        this.conn.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);
+
+        if (this.getContentLength() < 0) {
+            throw new ConnectionException("连接内容小于0");
+        }
+
+        int code = conn.getResponseCode();
+        RandomAccessFile raf = null;
+        try{
+            InputStream is = conn.getInputStream();
+            raf = new RandomAccessFile(this.file, "rwd");
+            raf.seek(startPos);
+
+            byte[] bs = new byte[1024];
+            int len = -1;
+
+            while ((len = is.read(bs)) != -1) {
+                raf.write(bs, 0, len);
+            }
+        }finally {
+            raf.close();
+        }
+
+
+
+    }
+
+    @Override
+    public int getContentLength() {
+        return this.conn.getContentLength();
+    }
+
+    @Override
+    public void close() {
+//        this.conn.
+
+    }
+}

group03/58555264/src/main/java/com/circle/download/impl/ConnectionManagerFactory.java

@@ -0,0 +1,31 @@
+package com.circle.download.impl;
+
+import com.circle.download.api.Connection;
+import com.circle.download.api.ConnectionManager;
+
+import java.io.File;
+
+/**
+ * Created by keweiyang on 2017/3/11.
+ */
+public class ConnectionManagerFactory {
+
+    private static volatile ConnectionManager manager = null;
+
+    private ConnectionManagerFactory() {
+
+    }
+
+    public static ConnectionManager getManager(File file) {
+
+        if (manager == null) {
+            synchronized (ConnectionManagerFactory.class) {
+                if (manager == null) {
+                    manager = new ConnectionManagerImpl(file);
+                }
+            }
+        }
+
+        return manager;
+    }
+}

group03/58555264/src/main/java/com/circle/download/impl/ConnectionManagerImpl.java

@@ -0,0 +1,31 @@
+package com.circle.download.impl;
+
+import com.circle.download.api.Connection;
+import com.circle.download.api.ConnectionException;
+import com.circle.download.api.ConnectionManager;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+
+/**
+ * Created by keweiyang on 2017/3/10.
+ */
+class ConnectionManagerImpl implements ConnectionManager {
+    private File file;
+
+    public ConnectionManagerImpl(File file) {
+
+        this.file = file;
+
+    }
+
+    @Override
+    public Connection open(String url) throws ConnectionException, IOException {
+        return new ConnectionImpl(url, this.file);
+    }
+
+
+}