From 9cb7321e22b6dafd1f9a0e78f87e80be3ba7dc77 Mon Sep 17 00:00:00 2001
From: Lizhy <lizhy@live.cn>
Date: Fri, 31 Mar 2017 16:37:51 +0800
Subject: [PATCH] =?UTF-8?q?=E8=A1=A5=E4=BA=A4=E7=AC=AC=E4=B8=89=E6=AC=A1?=
 =?UTF-8?q?=E4=BD=9C=E4=B8=9A?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

完成多线程下载
---
 .../homework/third/basic/LRUPageFameTest.java |  32 +++++
 .../homework/third/basic/LRUPageFrame.java    |  63 +++++++++
 .../homework/third/basic/LinkedList.java      | 125 ++++++++++++++++++
 .../third/download/DownloadThread.java        |  51 +++++++
 .../third/download/FileDownloader.java        |  86 ++++++++++++
 .../third/download/FileDownloaderTest.java    |  58 ++++++++
 .../third/download/api/Connection.java        |  28 ++++
 .../download/api/ConnectionException.java     |  12 ++
 .../third/download/api/ConnectionManager.java |  16 +++
 .../third/download/api/DownloadListener.java  |   5 +
 .../third/download/impl/ConnectionImpl.java   |  97 ++++++++++++++
 .../download/impl/ConnectionManagerImpl.java  |  54 ++++++++
 .../third/download/utils/HttpUtil.java        |  24 ++++
 13 files changed, 651 insertions(+)
 create mode 100644 group26/lizhy2017/homework/third/basic/LRUPageFameTest.java
 create mode 100644 group26/lizhy2017/homework/third/basic/LRUPageFrame.java
 create mode 100644 group26/lizhy2017/homework/third/basic/LinkedList.java
 create mode 100644 group26/lizhy2017/homework/third/download/DownloadThread.java
 create mode 100644 group26/lizhy2017/homework/third/download/FileDownloader.java
 create mode 100644 group26/lizhy2017/homework/third/download/FileDownloaderTest.java
 create mode 100644 group26/lizhy2017/homework/third/download/api/Connection.java
 create mode 100644 group26/lizhy2017/homework/third/download/api/ConnectionException.java
 create mode 100644 group26/lizhy2017/homework/third/download/api/ConnectionManager.java
 create mode 100644 group26/lizhy2017/homework/third/download/api/DownloadListener.java
 create mode 100644 group26/lizhy2017/homework/third/download/impl/ConnectionImpl.java
 create mode 100644 group26/lizhy2017/homework/third/download/impl/ConnectionManagerImpl.java
 create mode 100644 group26/lizhy2017/homework/third/download/utils/HttpUtil.java

diff --git a/group26/lizhy2017/homework/third/basic/LRUPageFameTest.java b/group26/lizhy2017/homework/third/basic/LRUPageFameTest.java
new file mode 100644
index 0000000000..32bf061852
--- /dev/null
+++ b/group26/lizhy2017/homework/third/basic/LRUPageFameTest.java
@@ -0,0 +1,32 @@
+package third.basic;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * ${}
+ * Created by spark_lizhy on 2017/3/31.
+ */
+
+public class LRUPageFameTest {
+    @Test
+    public void testAccess() {
+        LRUPageFrame frame = new LRUPageFrame(3);
+        frame.access(7);
+        frame.access(0);
+        frame.access(1);
+        Assert.assertEquals("1,0,7", frame.toString());
+        frame.access(2);
+        Assert.assertEquals("2,1,0", frame.toString());
+        frame.access(0);
+        Assert.assertEquals("0,2,1", frame.toString());
+        frame.access(0);
+        Assert.assertEquals("0,2,1", frame.toString());
+        frame.access(3);
+        Assert.assertEquals("3,0,2", frame.toString());
+        frame.access(0);
+        Assert.assertEquals("0,3,2", frame.toString());
+        frame.access(4);
+        Assert.assertEquals("4,0,3", frame.toString());
+    }
+}
diff --git a/group26/lizhy2017/homework/third/basic/LRUPageFrame.java b/group26/lizhy2017/homework/third/basic/LRUPageFrame.java
new file mode 100644
index 0000000000..29fa687bba
--- /dev/null
+++ b/group26/lizhy2017/homework/third/basic/LRUPageFrame.java
@@ -0,0 +1,63 @@
+package third.basic;
+
+/**
+ * ${}
+ * Created by spark_lizhy on 2017/3/31.
+ */
+/**
+ * 用双向链表实现 LRU 算法
+ * @author liuxin
+ *
+ */
+public class LRUPageFrame {
+
+    private static class Node {
+
+        Node prev;
+        Node next;
+        int pageNum;
+
+        Node() {
+        }
+    }
+
+    private int capacity;
+
+
+    private Node first;// 链表头
+    private Node last;// 链表尾
+
+
+    public LRUPageFrame(int capacity) {
+
+        this.capacity = capacity;
+
+    }
+
+    /**
+     * 获取缓存中对象
+     *
+     * @return
+     */
+    public void access(int pageNum) {
+
+
+    }
+
+
+
+    public String toString(){
+        StringBuilder buffer = new StringBuilder();
+        Node node = first;
+        while(node != null){
+            buffer.append(node.pageNum);
+
+            node = node.next;
+            if(node != null){
+                buffer.append(",");
+            }
+        }
+        return buffer.toString();
+    }
+
+}
diff --git a/group26/lizhy2017/homework/third/basic/LinkedList.java b/group26/lizhy2017/homework/third/basic/LinkedList.java
new file mode 100644
index 0000000000..b011033258
--- /dev/null
+++ b/group26/lizhy2017/homework/third/basic/LinkedList.java
@@ -0,0 +1,125 @@
+package third.basic;
+
+/**
+ * ${}
+ * Created by spark_lizhy on 2017/3/31.
+ */
+
+public class LinkedList {
+
+    private Node head;
+
+    public void add(Object o){
+
+    }
+    public void add(int index , Object o){
+
+    }
+    public Object get(int index){
+        return null;
+    }
+    public Object remove(int index){
+        return null;
+    }
+
+    public int size(){
+        return -1;
+    }
+
+    public void addFirst(Object o){
+
+    }
+    public void addLast(Object o){
+
+    }
+    public Object removeFirst(){
+        return null;
+    }
+    public Object removeLast(){
+        return null;
+    }
+//    public Iterator iterator(){
+//        return null;
+//    }
+
+
+    private static  class Node{
+        Object data;
+        Node next;
+
+    }
+
+    /**
+     * 把该链表逆置
+     * 例如链表为 3->7->10 , 逆置后变为  10->7->3
+     */
+    public  void reverse(){
+
+    }
+
+    /**
+     * 删除一个单链表的前半部分
+     * 例如：list = 2->5->7->8 , 删除以后的值为 7->8
+     * 如果 list = 2->5->7->8->10 , 删除以后的值为 7,8,10
+     */
+    public  void removeFirstHalf(){
+
+    }
+
+    /**
+     * 从第 i 个元素开始， 删除 length 个元素 ， 注意 i 从 0 开始
+     * @param i
+     * @param length
+     */
+    public  void remove(int i, int length){
+
+    }
+    /**
+     * 假定当前链表和 listB 均包含已升序排列的整数
+     * 从当前链表中取出那些 listB 所指定的元素
+     * 例如当前链表 = 11->101->201->301->401->501->601->701
+     * listB = 1->3->4->6
+     * 返回的结果应该是 [101,301,401,601]
+     * @param list
+     */
+    public  int[] getElements(LinkedList list){
+        return null;
+    }
+
+    /**
+     * 已知链表中的元素以值递增有序排列，并以单链表作存储结构。
+     * 从当前链表中中删除在 listB 中出现的元素
+     * @param list
+     */
+
+    public  void subtract(LinkedList list){
+
+    }
+
+    /**
+     * 已知当前链表中的元素以值递增有序排列，并以单链表作存储结构。
+     * 删除表中所有值相同的多余元素（使得操作后的线性表中所有元素的值均不相同）
+     */
+    public  void removeDuplicateValues(){
+
+    }
+
+    /**
+     * 已知链表中的元素以值递增有序排列，并以单链表作存储结构。
+     * 试写一高效的算法，删除表中所有值大于 min 且小于 max 的元素（若表中存在这样的元素）
+     * @param min
+     * @param max
+     */
+    public  void removeRange(int min, int max){
+
+    }
+
+    /**
+     * 假设当前链表和参数 list 指定的链表均以元素依值递增有序排列（同一表中的元素值各不相同）
+     * 现要求生成新链表 C，其元素为当前链表和 list 中元素的交集，且表 C 中的元素有依值递增有序排列
+     * @param list
+     */
+    public  LinkedList intersection( LinkedList list){
+        return null;
+    }
+}
diff --git a/group26/lizhy2017/homework/third/download/DownloadThread.java b/group26/lizhy2017/homework/third/download/DownloadThread.java
new file mode 100644
index 0000000000..9fa8cb2659
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/DownloadThread.java
@@ -0,0 +1,51 @@
+package third.download;
+
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+import third.download.api.Connection;
+import third.download.api.ConnectionException;
+import third.download.api.DownloadListener;
+
+public class DownloadThread extends Thread {
+
+    private RandomAccessFile accessFile;
+    private DownloadListener listener;
+    private Connection conn;
+    private int startPos;
+    private int endPos;
+
+    public DownloadThread(Connection conn, int startPos, int endPos, DownloadListener listener) {
+        this.listener = listener;
+        this.conn = conn;
+        this.startPos = startPos;
+        this.endPos = endPos;
+
+    }
+
+    public void run() {
+        try {
+            byte[] bytes = conn.read(startPos, endPos);
+            accessFile = new RandomAccessFile("./" + conn.getFileName(), "rw");
+            accessFile.seek(startPos);
+            accessFile.write(bytes);
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch (ConnectionException e) {
+            e.printStackTrace();
+        } finally {
+            if (null != accessFile)
+                try {
+                    accessFile.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+
+            if (null != conn)
+                conn.close();
+            if (null != listener)
+                listener.notifyFinished();
+        }
+    }
+}
diff --git a/group26/lizhy2017/homework/third/download/FileDownloader.java b/group26/lizhy2017/homework/third/download/FileDownloader.java
new file mode 100644
index 0000000000..498b09ee97
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/FileDownloader.java
@@ -0,0 +1,86 @@
+package third.download;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import third.download.api.Connection;
+import third.download.api.ConnectionException;
+import third.download.api.ConnectionManager;
+import third.download.api.DownloadListener;
+
+
+public class FileDownloader {
+	private final static int THREAD_NUM=15;
+	private String url;
+	private DownloadListener listener;
+	private ConnectionManager cm;
+	private AtomicInteger atomicInteger=new AtomicInteger();
+
+	public FileDownloader(String _url) {
+		this.url = _url;
+		
+	}
+	
+	public void execute(){
+		// 在这里实现你的代码， 注意： 需要用多线程实现下载
+		// 这个类依赖于其他几个接口, 你需要写这几个接口的实现代码
+		// (1) ConnectionManager , 可以打开一个连接，通过Connection可以读取其中的一段（用startPos, endPos来指定）
+		// (2) DownloadListener, 由于是多线程下载， 调用这个类的客户端不知道什么时候结束，所以你需要实现当所有
+		//     线程都执行完以后， 调用listener的notifiedFinished方法， 这样客户端就能收到通知。
+		// 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.getContentLength方法获得文件的长度
+		// 2. 至少启动3个线程下载，  注意每个线程需要先调用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
+		
+		// 下面的代码是示例代码， 也就是说只有一个线程， 你需要改造成多线程的。
+		Connection conn = null;
+		try {
+			int length = cm.getContentLength(url);
+			int perTread_lenth=length/THREAD_NUM;
+			int redundant=length%THREAD_NUM;
+			for (int i=0;i<THREAD_NUM;i++){
+				int startPos=i*perTread_lenth;
+				int endPos=(i+1)*perTread_lenth-1;
+				if (i==THREAD_NUM-1)
+					endPos+=redundant;
+			}
+			conn = cm.open(this.url);
+			atomicInteger.getAndIncrement();
+			new DownloadThread(conn, 0, length - 1, new DownloadListener() {
+				@Override
+				public void notifyFinished() {
+					if (atomicInteger.decrementAndGet()==0){
+						listener.notifyFinished();
+					}
+				}
+			}).start();
+			
+		} catch (ConnectionException e) {
+			e.printStackTrace();
+		}finally{
+			if(conn != null){
+				conn.close();
+			}
+		}
+		
+		
+		
+		
+	}
+	
+	public void setListener(DownloadListener listener) {
+		this.listener = listener;
+	}
+
+	
+	
+	public void setConnectionManager(ConnectionManager ucm){
+		this.cm = ucm;
+	}
+	
+	public DownloadListener getListener(){
+		return this.listener;
+	}
+	
+}
diff --git a/group26/lizhy2017/homework/third/download/FileDownloaderTest.java b/group26/lizhy2017/homework/third/download/FileDownloaderTest.java
new file mode 100644
index 0000000000..647d8931f8
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/FileDownloaderTest.java
@@ -0,0 +1,58 @@
+package third.download;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import third.download.api.ConnectionManager;
+import third.download.api.DownloadListener;
+import third.download.impl.ConnectionManagerImpl;
+
+
+
+public class FileDownloaderTest {
+	boolean downloadFinished = false;
+	@Before
+	public void setUp() throws Exception {
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void testDownload() {
+		
+		String url = "http://localhost:8080/test.jpg";
+		
+		FileDownloader downloader = new FileDownloader(url);
+
+	
+		ConnectionManager cm = new ConnectionManagerImpl();
+		downloader.setConnectionManager(cm);
+		
+		downloader.setListener(new DownloadListener() {
+			@Override
+			public void notifyFinished() {
+				downloadFinished = true;
+			}
+
+		});
+
+		
+		downloader.execute();
+		
+		// 等待多线程下载程序执行完毕
+		while (!downloadFinished) {
+			try {
+				System.out.println("还没有下载完成，休眠五秒");
+				//休眠5秒
+				Thread.sleep(5000);
+			} catch (InterruptedException e) {				
+				e.printStackTrace();
+			}
+		}
+		System.out.println("下载完成！");
+	}
+
+}
diff --git a/group26/lizhy2017/homework/third/download/api/Connection.java b/group26/lizhy2017/homework/third/download/api/Connection.java
new file mode 100644
index 0000000000..93508ad2b3
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/api/Connection.java
@@ -0,0 +1,28 @@
+package third.download.api;
+
+import java.io.IOException;
+
+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 返回的字节数组
+     */
+    public byte[] read(int startPos, int endPos) throws IOException, ConnectionException;
+
+    /**
+     * 得到数据内容的长度
+     *
+     * @return 资源的总长度
+     */
+    public int getContentLength();
+
+    /**
+     * 关闭连接
+     */
+    public void close();
+
+    public String getFileName();
+}
diff --git a/group26/lizhy2017/homework/third/download/api/ConnectionException.java b/group26/lizhy2017/homework/third/download/api/ConnectionException.java
new file mode 100644
index 0000000000..eeb9475ec9
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/api/ConnectionException.java
@@ -0,0 +1,12 @@
+package third.download.api;
+
+public class ConnectionException extends Exception {
+
+    public ConnectionException(String message) {
+        super("message:" + message);
+    }
+
+    public ConnectionException(Throwable cause){
+        super(cause);
+    }
+}
diff --git a/group26/lizhy2017/homework/third/download/api/ConnectionManager.java b/group26/lizhy2017/homework/third/download/api/ConnectionManager.java
new file mode 100644
index 0000000000..247c297636
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/api/ConnectionManager.java
@@ -0,0 +1,16 @@
+package third.download.api;
+
+public interface ConnectionManager {
+    /**
+     * 给定一个url , 打开一个连接
+     *
+     * @param url url
+     * @return 连接
+     */
+    public Connection open(String url) throws ConnectionException;
+
+    /**
+     * 获取长度
+     */
+    int getContentLength(String urlStr) throws ConnectionException;
+}
diff --git a/group26/lizhy2017/homework/third/download/api/DownloadListener.java b/group26/lizhy2017/homework/third/download/api/DownloadListener.java
new file mode 100644
index 0000000000..cb14f549ed
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/api/DownloadListener.java
@@ -0,0 +1,5 @@
+package third.download.api;
+
+public interface DownloadListener {
+    public void notifyFinished();
+}
diff --git a/group26/lizhy2017/homework/third/download/impl/ConnectionImpl.java b/group26/lizhy2017/homework/third/download/impl/ConnectionImpl.java
new file mode 100644
index 0000000000..149a0e683c
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/impl/ConnectionImpl.java
@@ -0,0 +1,97 @@
+package third.download.impl;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.UnknownServiceException;
+
+import third.download.api.Connection;
+import third.download.api.ConnectionException;
+import third.download.utils.HttpUtil;
+
+public class ConnectionImpl implements Connection {
+    private HttpURLConnection mConnection;
+    private ByteArrayOutputStream bos;
+    private InputStream is;
+
+    public ConnectionImpl(HttpURLConnection connection) {
+        super();
+        this.mConnection = 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 返回的字节数组
+     */
+    @Override
+    public byte[] read(int startPos, int endPos) throws IOException, ConnectionException {
+        mConnection.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);
+        mConnection.setInstanceFollowRedirects(true);
+        mConnection.setConnectTimeout(20000);
+        HttpUtil.checkStatus(mConnection);
+        byte[] bytes = new byte[Math.min(1024, endPos - startPos + 1)];
+        is = this.getInputStream();
+//        InputStream is = new BufferedInputStream(mConnection.getInputStream());
+        bos = new ByteArrayOutputStream();
+
+        int lenth = is.read(bytes);
+        while (lenth != -1)
+            bos.write(bytes, 0, lenth);
+
+        return bos.toByteArray();
+    }
+
+    /**
+     * 得到数据内容的长度
+     *
+     * @return 资源的总长度
+     */
+    @Override
+    public int getContentLength() {
+        return mConnection.getContentLength();
+    }
+
+    @Override
+    public void close() {
+        if (null != bos)
+            try {
+                bos.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+
+        if (null != is)
+            try {
+                is.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+
+        if (null != mConnection)
+            mConnection.disconnect();
+    }
+
+
+    @Override
+    public String getFileName() {
+        String fileName = null;
+        String field = mConnection.getHeaderField("Content-Disposition");
+        if(field == null ){
+            String urlStr = mConnection.getURL().toString();
+            fileName = urlStr.substring(urlStr.lastIndexOf("/")+1);
+        }else{
+            fileName=field.substring(field.indexOf("filename")+10, field.length()-1);
+        }
+        System.out.println(fileName);
+        return fileName;
+    }
+
+    public InputStream getInputStream() throws IOException {
+        throw new UnknownServiceException("protocol doesn\'t support input");
+    }
+
+}
diff --git a/group26/lizhy2017/homework/third/download/impl/ConnectionManagerImpl.java b/group26/lizhy2017/homework/third/download/impl/ConnectionManagerImpl.java
new file mode 100644
index 0000000000..d7ae5e8789
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/impl/ConnectionManagerImpl.java
@@ -0,0 +1,54 @@
+package third.download.impl;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import third.download.api.Connection;
+import third.download.api.ConnectionException;
+import third.download.api.ConnectionManager;
+import third.download.utils.HttpUtil;
+
+/**
+ * 连接管理器
+ */
+public class ConnectionManagerImpl implements ConnectionManager {
+
+    /**
+     * 给定一个url , 打开一个连接
+     */
+    @Override
+    public Connection open(String url) throws ConnectionException {
+        HttpURLConnection connection = getConnection(url);
+        return new ConnectionImpl(connection);
+    }
+
+    @Override
+    public int getContentLength(String urlStr) throws ConnectionException {
+        HttpURLConnection connection=getConnection(urlStr);
+        int length=0;
+        try {
+            HttpUtil.checkStatus(connection);
+            length=connection.getContentLength();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }finally {
+            connection.disconnect();
+        }
+        return length;
+    }
+
+    private HttpURLConnection getConnection(String _url) throws ConnectionException {
+        URL url = null;
+        HttpURLConnection connection = null;
+        try {
+            url = new URL(_url);
+            connection = (HttpURLConnection) url.openConnection();
+            connection.setRequestMethod("GET");
+            return connection;
+        } catch (IOException e) {
+            new ConnectionException(e);
+        return null;
+        }
+    }
+}
diff --git a/group26/lizhy2017/homework/third/download/utils/HttpUtil.java b/group26/lizhy2017/homework/third/download/utils/HttpUtil.java
new file mode 100644
index 0000000000..847be46a03
--- /dev/null
+++ b/group26/lizhy2017/homework/third/download/utils/HttpUtil.java
@@ -0,0 +1,24 @@
+package third.download.utils;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+
+import third.download.api.ConnectionException;
+
+/**
+ * ${}
+ * Created by spark_lizhy on 2017/3/31.
+ */
+
+public class HttpUtil {
+    /**
+     * 检查连接状态
+     */
+    public static void checkStatus(HttpURLConnection connection) throws IOException, ConnectionException {
+        int responseCode = connection.getResponseCode();
+        System.out.println("server response code: " + responseCode);
+        if (responseCode != HttpURLConnection.HTTP_OK && responseCode != HttpURLConnection.HTTP_PARTIAL) {
+            throw new ConnectionException("server response code: " + responseCode);
+        }
+    }
+}