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Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
package com.github.FelixCJF.coding2017.coderising.download;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

import com.github.FelixCJF.coding2017.coderising.download.api.Connection;

public class DownloadThread extends Thread{

Connection conn;
int startPos;
int endPos;

public DownloadThread( Connection conn, int startPos, int endPos){

this.conn = conn;
this.startPos = startPos;
this.endPos = endPos;
}
public void run(){
System.out.println("下载开始");
try {
byte[] buff = conn.read(startPos, endPos);
//创建一个可随机写入文件
RandomAccessFile randomAccessFile = new RandomAccessFile(new File("G:/"), "rwd");
randomAccessFile.seek(startPos);
randomAccessFile.write(buff, 0, buff.length);
randomAccessFile.close();

System.out.println("下载结束");
} catch (IOException e) {
e.printStackTrace();
}

}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,87 @@
package com.github.FelixCJF.coding2017.coderising.download;

import com.github.FelixCJF.coding2017.coderising.download.api.Connection;
import com.github.FelixCJF.coding2017.coderising.download.api.ConnectionException;
import com.github.FelixCJF.coding2017.coderising.download.api.ConnectionManager;
import com.github.FelixCJF.coding2017.coderising.download.api.DownloadListener;

public class FileDownloader {

String url;

DownloadListener listener;

ConnectionManager cm;


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 {

conn = cm.open(this.url);
int length = conn.getContentLength();
//自定义线程数量
int threadCount = 3;
//计算每条线程下载数据的大小
int blockSize = length/threadCount;

for (int threadId = 0; threadId <= threadCount; threadCount++) {

//定义每个线程开始以及结束的下载位置
// 开始下载的位置
int startPos = (threadId - 1) * blockSize;
// 结束下载的位置(不包含最后一块)
int endPos = (threadId * blockSize) - 1;
if (threadCount == threadId) {
endPos = length;
}
new DownloadThread(conn,0,length-1).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;
}

}
Original file line number Diff line number Diff line change
@@ -0,0 +1,60 @@
package com.github.FelixCJF.coding2017.coderising.download;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.github.FelixCJF.coding2017.coderising.download.api.ConnectionManager;
import com.github.FelixCJF.coding2017.coderising.download.api.DownloadListener;
import com.github.FelixCJF.coding2017.coderising.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 = "https://www.baidu.com/img/bd_logo.png";

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!");



}

}
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
package com.github.FelixCJF.coding2017.coderising.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
*/
public byte[] read(int startPos,int endPos) throws IOException;
/**
* 得到数据内容的长度
* @return
*/
public int getContentLength();

/**
* 关闭连接
*/
public void close();
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
package com.github.FelixCJF.coding2017.coderising.download.api;

public class ConnectionException extends Exception {

}
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
package com.github.FelixCJF.coding2017.coderising.download.api;

public interface ConnectionManager {
/**
* 给定一个url , 打开一个连接
* @param url
* @return
*/
public Connection open(String url) throws ConnectionException;
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
package com.github.FelixCJF.coding2017.coderising.download.api;

public interface DownloadListener {
public void notifyFinished();
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,54 @@
package com.github.FelixCJF.coding2017.coderising.download.impl;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URLConnection;

import com.github.FelixCJF.coding2017.coderising.download.api.Connection;


public class ConnectionImpl implements Connection{


public URLConnection urlConnection;

public ConnectionImpl(URLConnection urlConnection) {
this.urlConnection = urlConnection;
}

@Override
public byte[] read(int startPos, int endPos) throws IOException {
//设置连接超时属性
urlConnection.setReadTimeout(5000);

urlConnection.setRequestProperty("Range", "bytes=" + startPos + "-" + endPos);

BufferedInputStream inputStream= new BufferedInputStream(urlConnection.getInputStream());
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

byte[] buff = new byte[1024];
int len = 0;

while ((len = inputStream.read(buff)) != -1) {
outputStream.write(buff,0,len);
}
byte[] temp = outputStream.toByteArray();

inputStream.close();
outputStream.close();

return temp;
}

@Override
public int getContentLength() {
return urlConnection.getContentLength();
}

@Override
public void close() {
urlConnection = null;
}

}
Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
package com.github.FelixCJF.coding2017.coderising.download.impl;


import java.net.URL;

import com.github.FelixCJF.coding2017.coderising.download.api.Connection;
import com.github.FelixCJF.coding2017.coderising.download.api.ConnectionException;
import com.github.FelixCJF.coding2017.coderising.download.api.ConnectionManager;

public class ConnectionManagerImpl implements ConnectionManager {

@Override
public Connection open(String url) throws ConnectionException {
Connection connection = null;
try {

connection = new ConnectionImpl(new URL(url).openConnection());

} catch (Exception e) {
e.printStackTrace();
}
return connection;
}

}
Original file line number Diff line number Diff line change
@@ -1,39 +1,43 @@
package com.coderising.litestruts;

/**
* 这是一个用来展示登录的业务类, 其中的用户名和密码都是硬编码的。
* @author liuxin
*
*/
public class LoginAction{
private String name ;
private String password;
private String message;

public String getName() {
return name;
}

public String getPassword() {
return password;
}

public String execute(){
if("test".equals(name) && "1234".equals(password)){
this.message = "login successful";
return "success";
}
this.message = "login failed,please check your user/pwd";
return "fail";
}

public void setName(String name){
this.name = name;
}
public void setPassword(String password){
this.password = password;
}
public String getMessage(){
return this.message;
}
}
package com.github.FelixCJF.coding2017.coderising.litestruts;

/**
* 这是一个用来展示登录的业务类, 其中的用户名和密码都是硬编码的。
* @author liuxin
*
*/
public class LoginAction{
private String name ;
private String password;
private String message;

public String getName() {
return name;
}

public String getPassword() {
return password;
}

public String execute(){
if("test".equals(name) && "1234".equals(password)){
this.message = "login successful";
return "success";
}
this.message = "login failed,please check your user/pwd";
return "fail";
}

public void setName(String name){
this.name = name;
}
public void setPassword(String password){
this.password = password;
}
public String getMessage(){
return this.message;
}

public void setMessage(String message) {
this.message = message;
}
}
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