diff --git a/group27/513274874/homework/src/com/coding/basic/LinkedList.java b/group27/513274874/homework/src/com/coding/basic/LinkedList.java index d66be49758..1d574e8aa3 100644 --- a/group27/513274874/homework/src/com/coding/basic/LinkedList.java +++ b/group27/513274874/homework/src/com/coding/basic/LinkedList.java @@ -185,4 +185,81 @@ public void setNext(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; + } + + } \ No newline at end of file diff --git a/group27/513274874/homework/src/com/coding/coderising/download/DownloadThread.java b/group27/513274874/homework/src/com/coding/coderising/download/DownloadThread.java index 1456314140..eca4a105e6 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/DownloadThread.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/DownloadThread.java @@ -1,6 +1,9 @@ -package com.coderising.download; +package com.coding.coderising.download; -import com.coderising.download.api.Connection; +import com.coding.coderising.download.api.Connection; + +import java.io.IOException; +import java.io.RandomAccessFile; public class DownloadThread extends Thread{ @@ -8,13 +11,20 @@ public class DownloadThread extends Thread{ int startPos; int endPos; + // 将下载到的字节输出到raf中 + private RandomAccessFile raf; + public DownloadThread( Connection conn, int startPos, int endPos){ this.conn = conn; this.startPos = startPos; this.endPos = endPos; } - public void run(){ - + public void run(){ + try { + conn.read(startPos,endPos); + } catch (IOException e) { + e.printStackTrace(); + } } } diff --git a/group27/513274874/homework/src/com/coding/coderising/download/FileDownloader.java b/group27/513274874/homework/src/com/coding/coderising/download/FileDownloader.java index f5d7999eb4..dc99e91598 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/FileDownloader.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/FileDownloader.java @@ -1,9 +1,9 @@ -package com.coderising.download; +package com.coding.coderising.download; -import com.coderising.download.api.Connection; -import com.coderising.download.api.ConnectionException; -import com.coderising.download.api.ConnectionManager; -import com.coderising.download.api.DownloadListener; +import com.coding.coderising.download.api.Connection; +import com.coding.coderising.download.api.ConnectionException; +import com.coding.coderising.download.api.ConnectionManager; +import com.coding.coderising.download.api.DownloadListener; public class FileDownloader { diff --git a/group27/513274874/homework/src/com/coding/coderising/download/FileDownloaderTest.java b/group27/513274874/homework/src/com/coding/coderising/download/FileDownloaderTest.java index 8171ee5763..8a9531530f 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/FileDownloaderTest.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/FileDownloaderTest.java @@ -1,12 +1,12 @@ -package com.coderising.download; +package com.coding.coderising.download; import org.junit.After; import org.junit.Before; import org.junit.Test; -import com.coderising.download.api.ConnectionManager; -import com.coderising.download.api.DownloadListener; -import com.coderising.download.impl.ConnectionManagerImpl; +import com.coding.coderising.download.api.ConnectionManager; +import com.coding.coderising.download.api.DownloadListener; +import com.coding.coderising.download.impl.ConnectionManagerImpl; public class FileDownloaderTest { boolean downloadFinished = false; diff --git a/group27/513274874/homework/src/com/coding/coderising/download/api/Connection.java b/group27/513274874/homework/src/com/coding/coderising/download/api/Connection.java index 9710e270e1..1b00c983d6 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/api/Connection.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/api/Connection.java @@ -1,4 +1,4 @@ -package com.coderising.download.api; +package com.coding.coderising.download.api; import java.io.IOException; diff --git a/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionException.java b/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionException.java index 8dbfe95dda..e08c73bd98 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionException.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionException.java @@ -1,4 +1,4 @@ -package com.coderising.download.api; +package com.coding.coderising.download.api; public class ConnectionException extends Exception { diff --git a/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionManager.java b/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionManager.java index fb44ede457..f95561e023 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionManager.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/api/ConnectionManager.java @@ -1,4 +1,4 @@ -package com.coderising.download.api; +package com.coding.coderising.download.api; public interface ConnectionManager { /** diff --git a/group27/513274874/homework/src/com/coding/coderising/download/api/DownloadListener.java b/group27/513274874/homework/src/com/coding/coderising/download/api/DownloadListener.java index 4cd0b3eab1..32c399a204 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/api/DownloadListener.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/api/DownloadListener.java @@ -1,4 +1,4 @@ -package com.coderising.download.api; +package com.coding.coderising.download.api; public interface DownloadListener { public void notifyFinished(); diff --git a/group27/513274874/homework/src/com/coding/coderising/download/demo/DownThread.java b/group27/513274874/homework/src/com/coding/coderising/download/demo/DownThread.java new file mode 100644 index 0000000000..b675d65c9d --- /dev/null +++ b/group27/513274874/homework/src/com/coding/coderising/download/demo/DownThread.java @@ -0,0 +1,72 @@ +package com.coding.coderising.download.demo; + +import java.io.InputStream; +import java.io.RandomAccessFile; + +public class DownThread extends Thread { + + // 定义字节数组（取水的竹筒）的长度 + private final int BUFF_LEN = 32; + + // 定义下载的起始点 + private long start; + + // 定义下载的结束点 + private long end; + + // 下载资源对应的输入流 + private InputStream is; + + // 将下载到的字节输出到raf中 + private RandomAccessFile raf; + + + // 构造器，传入输入流，输出流和下载起始点、结束点 + public DownThread(long start, long end, InputStream is, RandomAccessFile raf) { + // 输出该线程负责下载的字节位置 + System.out.println(start + "---->" + end); + this.start = start; + this.end = end; + this.is = is; + this.raf = raf; + } + + @Override + public void run() { + try { + is.skip(start); + raf.seek(start); + // 定义读取输入流内容的的缓存数组（竹筒） + byte[] buff = new byte[BUFF_LEN]; + // 本线程负责下载资源的大小 + long contentLen = end - start; + // 定义最多需要读取几次就可以完成本线程的下载 + long times = contentLen / BUFF_LEN + 4; + // 实际读取的字节数 + int hasRead = 0; + for (int i = 0; i < times; i++) { + hasRead = is.read(buff); + // 如果读取的字节数小于0，则退出循环！ + if (hasRead < 0) { + break; + } + raf.write(buff, 0, hasRead); + } + } catch (Exception ex) { + ex.printStackTrace(); + } + // 使用finally块来关闭当前线程的输入流、输出流 + finally { + try { + if (is != null) { + is.close(); + } + if (raf != null) { + raf.close(); + } + } catch (Exception ex) { + ex.printStackTrace(); + } + } + } +} \ No newline at end of file diff --git a/group27/513274874/homework/src/com/coding/coderising/download/demo/MutilDown.java b/group27/513274874/homework/src/com/coding/coderising/download/demo/MutilDown.java new file mode 100644 index 0000000000..3b6cfa020d --- /dev/null +++ b/group27/513274874/homework/src/com/coding/coderising/download/demo/MutilDown.java @@ -0,0 +1,72 @@ +package com.coding.coderising.download.demo; + +import java.io.InputStream; +import java.io.RandomAccessFile; +import java.net.URL; +import java.net.URLConnection; + +public class MutilDown { + + public static void main(String[] args) { + //定义几个线程去下载 + final int DOWN_THREAD_NUM = 4; + final String OUT_FILE_NAME = "down.jpg"; + InputStream[] isArr = new InputStream[DOWN_THREAD_NUM]; + RandomAccessFile[] outArr = new RandomAccessFile[DOWN_THREAD_NUM]; + try { + // 创建一个URL对象 + URL url = new URL("http://hiphotos.baidu.com/240728057/pic/item/6a50e38242aad8f60cf4d2b3.jpg"); + // 以此URL对象打开第一个输入流 + isArr[0] = url.openStream(); + long fileLen = getFileLength(url); + System.out.println("网络资源的大小" + fileLen); + // 以输出文件名创建第一个RandomAccessFile输出流 + //创建从中读取和向其中写入（可选）的随机存取文件流，第一个参数：文件名，第二个参数是：参数指定用以打开文件的访问模式 + //"rw"可能是可读可写， + outArr[0] = new RandomAccessFile(OUT_FILE_NAME, "rw"); + // 创建一个与下载资源相同大小的空文件 + for (int i = 0; i < fileLen; i++) { + outArr[0].write(0); + } + // 每线程应该下载的字节数 + long numPerThred = fileLen / DOWN_THREAD_NUM; + // 整个下载资源整除后剩下的余数取模 + long left = fileLen % DOWN_THREAD_NUM; + for (int i = 0; i < DOWN_THREAD_NUM; i++) { + // 为每个线程打开一个输入流、一个RandomAccessFile对象， + // 让每个线程分别负责下载资源的不同部分。 + //isArr[0]和outArr[0]已经使用，从不为0开始 + if (i != 0) { + // 以URL打开多个输入流 + isArr[i] = url.openStream(); + // 以指定输出文件创建多个RandomAccessFile对象 + outArr[i] = new RandomAccessFile(OUT_FILE_NAME, "rw"); + } + // 分别启动多个线程来下载网络资源 + if (i == DOWN_THREAD_NUM - 1) { + // 最后一个线程下载指定numPerThred+left个字节 + new DownThread(i * numPerThred, (i + 1) * numPerThred + + left, isArr[i], outArr[i]).start(); + } else { + // 每个线程负责下载一定的numPerThred个字节 + new DownThread(i * numPerThred, (i + 1) * numPerThred, + isArr[i], outArr[i]).start(); + } + } + } catch (Exception ex) { + ex.printStackTrace(); + } + } + + // 定义获取指定网络资源的长度的方法 + public static long getFileLength(URL url) throws Exception { + long length = 0; + // 打开该URL对应的URLConnection + URLConnection con = url.openConnection(); + // 获取连接URL资源的长度 + long size = con.getContentLength(); + length = size; + return length; + } + +} \ No newline at end of file diff --git a/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionImpl.java b/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionImpl.java index 32f03efdc7..e1f649b88b 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionImpl.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionImpl.java @@ -1,27 +1,100 @@ -package com.coderising.download.impl; +package com.coding.coderising.download.impl; -import java.io.IOException; +import com.coding.coderising.download.api.Connection; -import com.coderising.download.api.Connection; +import java.io.*; +import java.net.URL; +import java.net.URLConnection; -public class ConnectionImpl implements Connection{ +public class ConnectionImpl implements Connection { + private URL url; - @Override - public byte[] read(int startPos, int endPos) throws IOException { - - return null; - } + // 定义字节数组（取水的竹筒）的长度 + private final int BUFF_LEN = 32; - @Override - public int getContentLength() { - - return 0; - } + // 下载资源对应的输入流 + private InputStream is; - @Override - public void close() { - - - } + ByteArrayOutputStream bos; + + @Override + public byte[] read(int startPos, int endPos) throws IOException { + + this.is = url.openStream(); + + is.skip(startPos); + // 定义读取输入流内容的的缓存数组（竹筒） + byte[] buff = new byte[BUFF_LEN]; + // 本线程负责下载资源的大小 + long contentLen = endPos - startPos; + bos = new ByteArrayOutputStream((int) contentLen); + BufferedInputStream in = new BufferedInputStream(is); + int len = 0; + while (-1 != (len = in.read(buff, 0, BUFF_LEN))) { + bos.write(buff, 0, len); + } + return bos.toByteArray(); + } +// @Override +// public byte[] read(int startPos, int endPos) throws IOException { +// raf = new RandomAccessFile("newfile.jpg", "rw"); +// this.is = url.openStream(); +// +// is.skip(startPos); +// raf.seek(startPos); +// // 定义读取输入流内容的的缓存数组（竹筒） +// byte[] buff = new byte[BUFF_LEN]; +// // 本线程负责下载资源的大小 +// long contentLen = endPos - startPos; +// ByteArrayOutputStream bos = new ByteArrayOutputStream((int) contentLen); +// // 定义最多需要读取几次就可以完成本线程的下载 +// long times = contentLen / BUFF_LEN + 4; +// // 实际读取的字节数 +// int hasRead = 0; +// for (int i = 0; i < times; i++) { +// hasRead = is.read(buff); +// // 如果读取的字节数小于0，则退出循环！ +// if (hasRead < 0) { +// break; +// } +// raf.write(buff, 0, hasRead); +// } +// +// return null; +// } + + @Override + public int getContentLength() { + int length = 0; + // 打开该URL对应的URLConnection + URLConnection con = null; + try { + con = url.openConnection(); + } catch (IOException e) { + e.printStackTrace(); + } + // 获取连接URL资源的长度 + length = con.getContentLength(); + return length; + } + + @Override + public void close() { + try { + if (is != null) { + is.close(); + } + if (bos != null) { + bos.close(); + } + } catch (IOException e) { + e.printStackTrace(); + } + + } + + public ConnectionImpl(URL url) { + this.url = url; + } } diff --git a/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionManagerImpl.java b/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionManagerImpl.java index 046f7c49a4..2295167f6d 100644 --- a/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionManagerImpl.java +++ b/group27/513274874/homework/src/com/coding/coderising/download/impl/ConnectionManagerImpl.java @@ -1,15 +1,29 @@ -package com.coderising.download.impl; +package com.coding.coderising.download.impl; -import com.coderising.download.api.Connection; -import com.coderising.download.api.ConnectionException; -import com.coderising.download.api.ConnectionManager; +import com.coding.coderising.download.api.Connection; +import com.coding.coderising.download.api.ConnectionException; +import com.coding.coderising.download.api.ConnectionManager; + +import java.net.MalformedURLException; +import java.net.URL; public class ConnectionManagerImpl implements ConnectionManager { @Override public Connection open(String url) throws ConnectionException { - - return null; + + Connection connection = null; + try { + if(url == null || "".equals(url.trim())) return null; + + URL urlO = new URL(url); + connection = new ConnectionImpl(urlO); + + + } catch (MalformedURLException e) { + e.printStackTrace(); + } + return connection; } }