第四周作业

group24/494800949/src/main/java/com/coding/mini_jvm/src/com/coderising/jvm/loader/ClassFileLoader.java

@@ -0,0 +1,59 @@
+package com.coding.mini_jvm.src.com.coderising.jvm.loader;
+
+import java.io.*;
+import java.util.ArrayList;
+import java.util.List;
+
+
+
+public class ClassFileLoader {
+
+	private static final String CLASS_FILE_SUFFIX = ".class";
+	private List<String> clzPaths = new ArrayList<String>();
+
+	public byte[] readBinaryCode(String className) {
+		String classPath = getClassPath();
+		String[] paths = classPath.split(File.pathSeparator);
+		className = className.replaceAll("\\.", "\\"+File.separator) ;
+		for (String path : paths) {
+			String filename = path + File.separator + className + CLASS_FILE_SUFFIX;
+			File file = new File(filename);
+			if (file.exists()) {
+				try {
+					FileInputStream fis = new FileInputStream(file);
+					BufferedInputStream bis = new BufferedInputStream(fis);
+					byte[] data = new byte[bis.available()];
+					bis.read(data);
+					return data;
+				} catch (FileNotFoundException e) {
+					e.printStackTrace();
+				} catch (IOException e) {
+					e.printStackTrace();
+				}
+			}
+		}
+		return null;
+	}
+
+
+	public void addClassPath(String path) {
+		clzPaths.add(path);
+	}
+
+
+
+	public String getClassPath(){
+		StringBuffer sb = new StringBuffer();
+		for (String path : clzPaths) {
+			sb.append(path);
+			sb.append(";");
+		}
+		String path = sb.toString();
+		return path.substring(0, path.lastIndexOf(";"));
+	}
+
+
+
+
+
+}

group24/494800949/src/main/java/com/coding/week3/download/FileDownloader.java

@@ -68,7 +68,6 @@ public void execute() throws IOException {
                 lastLen = fileLength % nThread;
                 perLenOfThread = (fileLength + (nThread - lastLen)) / nThread;
             }
-			//计算
 
 			//启动线程
 			for (int i = 0; i < nThread; i++) {
@@ -87,7 +86,7 @@ public void execute() throws IOException {
 
 		} catch (ConnectionException e) {
 			e.printStackTrace();
-		}finally{
+		} finally{
 			if(conn != null){
 				conn.close();
 			}

group24/494800949/src/main/java/com/coding/week3/download/impl/ConnectionImpl.java

@@ -6,6 +6,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
+import java.util.concurrent.TimeUnit;
 
 
 public class ConnectionImpl implements Connection {
@@ -48,8 +49,20 @@ public void close() {
 	}
 
 	@Override
-	public InputStream getInputStream() throws IOException {
-		return httpURLConnection.getInputStream();
+	public InputStream getInputStream()  {
+		try {
+			return httpURLConnection.getInputStream();
+		} catch (IOException e) {
+			for (int i = 0; i < 5; i++) {
+				try {
+					TimeUnit.SECONDS.sleep(10);
+					return httpURLConnection.getInputStream();
+				} catch (IOException | InterruptedException e1) {
+					e1.printStackTrace();
+				}
+			}
+			throw new RuntimeException(e);
+		}
 	}
 
 }

group24/494800949/src/main/java/com/coding/week3/download1/DownloadTask.java

@@ -0,0 +1,93 @@
+package com.coding.week3.download1;
+
+import com.coding.week3.download1.api.Connection;
+import com.coding.week3.download1.api.ConnectionManager;
+
+import java.io.*;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Created by Administrator on 2017/3/31 0031.
+ */
+public class DownloadTask implements Runnable {
+    private static final int BUFF_SIZE = 1024;
+    ConnectionManager connectionManager;
+    int               startPos;
+    int               endPos;
+    RandomAccessFile  ras;
+    AtomicInteger     totalDownloadBytesCount;
+    AtomicInteger     eachThreadDownloadBytesCount;
+    String            url;
+
+    public DownloadTask(String url, ConnectionManager connectionManager, int startPos, int endPos, RandomAccessFile ras, AtomicInteger totalDownloadBytesCount) {
+        this.url = url;
+        this.connectionManager = connectionManager;
+        this.startPos = startPos;
+        this.endPos = endPos;
+        this.ras = ras;
+        this.totalDownloadBytesCount = totalDownloadBytesCount;
+        this.eachThreadDownloadBytesCount = new AtomicInteger(0);
+    }
+
+    @Override
+    public void run() {
+        Connection conn = null;
+        InputStream is = null;
+        try {
+            conn = connectionManager.open(url);
+            is = getInputStream(conn);
+            is.skip(startPos);
+            ras.seek(startPos);
+            byte[] bytes = new byte[BUFF_SIZE];
+            int hasRead;
+            int readTimes = (endPos - startPos) / BUFF_SIZE + 4;
+            for (int i = 0; i < readTimes; i++) {
+                hasRead = is.read(bytes);
+                if (hasRead == -1) {
+                    break;
+                }
+                ras.write(bytes, 0, hasRead);
+                totalDownloadBytesCount.getAndAdd(hasRead);
+                eachThreadDownloadBytesCount.getAndAdd(hasRead);
+            }
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+
+    private InputStream getInputStream(Connection connection){
+        Connection conn = null;
+        InputStream is = null;
+        try {
+            conn = connectionManager.open(url);
+            is = conn.getInputStream();
+            return is;
+        } catch (IOException e) {
+            for (int i = 0; i < 5; i++) {
+                try {
+                    TimeUnit.SECONDS.sleep(5);
+                    conn = connectionManager.open(url);
+                    is = conn.getInputStream();
+                    is.skip(startPos);
+                    break;
+                } catch (InterruptedException e1) {
+                    e1.printStackTrace();
+                } catch (IOException e1) {
+                    System.out.println(e1.getMessage());
+                }
+            }
+            throw new RuntimeException("连接超时", e);
+        }
+
+    }
+
+
+
+
+    public int getEachThreadDownloadBytesCount() {
+        return eachThreadDownloadBytesCount.get();
+    }
+}

group24/494800949/src/main/java/com/coding/week3/download1/FileDownloader.java

@@ -0,0 +1,167 @@
+package com.coding.week3.download1;
+
+
+import com.coding.week3.download1.api.Connection;
+import com.coding.week3.download1.api.ConnectionException;
+import com.coding.week3.download1.api.ConnectionManager;
+import com.coding.week3.download1.api.DownloadListener;
+
+import java.io.*;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class FileDownloader {
+
+	String url;
+
+	DownloadListener listener;
+
+	ConnectionManager cm;
+
+	String savePath;
+
+	int nThread;
+
+	int fileLength;
+
+	AtomicInteger downloadBytesCount;
+
+	public FileDownloader(String _url) {
+		this.url = _url;
+	}
+
+	public FileDownloader(int nThread, String savePath, String url) {
+		this.nThread = nThread;
+		this.savePath = savePath;
+		this.url = url;
+		downloadBytesCount = new AtomicInteger(0);
+	}
+
+	public void execute() throws IOException {
+		// 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;
+		DownloadTask[] downloadTasks = new DownloadTask[nThread];
+		try {
+
+			//根据文件长度为每个线程分配下载字节数量
+			conn = cm.open(this.url);
+			fileLength = conn.getContentLength();
+			//已读字节数量
+			ExecutorService executorService = Executors.newFixedThreadPool(nThread);
+//			int[][] allotSize = alloctSize(nThread, fileLength);
+			int[][] allotSize = readPos(nThread, fileLength);
+			for (int i = 0; i < nThread; i++) {
+				RandomAccessFile ras = new RandomAccessFile(savePath, "rw");
+				downloadTasks[i] = new DownloadTask(url, cm, allotSize[0][i],
+						allotSize[1][i], ras , downloadBytesCount);
+				executorService.execute(downloadTasks[i]);
+			}
+			//关闭线程池
+			executorService.shutdown();
+			boolean isTermination ;
+			do {
+				isTermination = executorService.awaitTermination(500, TimeUnit.MILLISECONDS);
+				if (fileLength > 0)
+					System.out.println("已下载："+(downloadBytesCount.get()/1024)+"K,百分比："+ (downloadBytesCount.get()/ (fileLength/100))+"%" );
+				//循环等待，直到线程全部关闭
+			} while (!isTermination);
+			System.out.println(111111);
+
+		} catch (ConnectionException e) {
+			e.printStackTrace();
+		} catch (InterruptedException e) {
+			e.printStackTrace();
+		} finally{
+			writePos(downloadTasks);
+			if(conn != null){
+				conn.close();
+			}
+		}
+	}
+
+	private int[][] alloctSize(int nThread, int fileLength){
+		int[][] allotSize = new int[2][nThread];
+		int perLenOfTask = fileLength / nThread;
+		int lastLen = fileLength % nThread;
+		for (int i = 0; i < nThread; i++) {
+			int start = perLenOfTask * i;
+			int end = perLenOfTask * (i + 1) - 1;
+			if (i == nThread - 1) {
+				end += lastLen;
+			}
+			allotSize[0][i] = start;
+			allotSize[1][i] = end;
+		}
+		return allotSize;
+	}
+
+	public void setListener(DownloadListener listener) {
+		this.listener = listener;
+	}
+
+	public void setConnectionManager(ConnectionManager ucm){
+		this.cm = ucm;
+	}
+
+	public DownloadListener getListener(){
+		return this.listener;
+	}
+
+	private void writePos(DownloadTask[] tasks){
+		File file = new File("");
+		File posFile = new File(file.getAbsolutePath()+"/tempPos");
+		RandomAccessFile ras = null;
+		try {
+			ras = new RandomAccessFile(posFile, "rw");
+			if (!posFile.exists())  {
+				posFile.createNewFile();
+			}
+			for (int i = 0; i < tasks.length; i++) {
+				ras.writeInt(tasks[i].getEachThreadDownloadBytesCount());
+				ras.writeInt(tasks[i].endPos);
+			}
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+	private int[][] readPos(int nThread, int fileLength){
+		File file = new File("");
+		File posFile = new File(file.getAbsolutePath()+"/tempPos");
+		if (!posFile.exists()) {
+			return alloctSize(nThread, fileLength);
+		}
+		RandomAccessFile ras = null;
+		int[][] pos = new int[2][nThread];
+		try {
+			ras = new RandomAccessFile(posFile, "r");
+			ras.seek(0);
+			for (int i = 0; i < nThread; i++) {
+				pos[0][i]  = ras.readInt();
+				pos[1][i]  = ras.readInt();
+			}
+			return pos;
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+		return pos;
+	}
+}

group24/494800949/src/main/java/com/coding/week3/download1/api/Connection.java

@@ -0,0 +1,26 @@
+package com.coding.week3.download1.api;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+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
+	 */
+	 byte[] read(int startPos, int endPos) throws IOException;
+	/**
+	 * 得到数据内容的长度
+	 * @return
+	 */
+	 int getContentLength();
+
+	/**
+	 * 关闭连接
+	 */
+	 void close();
+
+	 InputStream getInputStream() throws IOException;
+}