假设源文件夹sourcefold中随时可能有新文件加进来, 现在需要把源文件夹中的文件拷贝到目标文件夹descfold中。
要求： 用两个线程来实现，一个线程监视源文件夹中是否有新加的文件，当有新文件时，用另一个线程将文件拷贝到目标文件夹中。
请给个示范代码，最好能直接跑的，谢谢！
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老的别用了。
试试jdk1.7的新玩意吧。
http://www.oschina.net/question/100896_28983
有代码，有解释。 很好很强的。 就是有点长，耐心看完吧。
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- Java code
package testNew;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.util.Arrays;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;public class Test { public final static Map<String,String> fileMap = new HashMap<String,String>(); public final static String readFileName = "D:" + File.separator + "hello"; public final static String writeFileName = "D:" + File.separator + "back"; public static void main(String[] args) { ReadThread read = new ReadThread(); WriteThread write = new WriteThread(); read.start(); write.start(); } /** *返回目录下文件 */ public static List<String> printfFile(String fileName){ File file = new File(fileName); String[] fileList = file.list();//获得该目录下所有文件的名字，包含隐藏文件 for(String s : fileList){ System.out.println(s); } return Arrays.asList(fileList); } /** *拷贝文件 */ public static void copyFile(String fileName,String fileName1) throws IOException { File file = new File(fileName); File file1 = new File(fileName1); FileInputStream fileStream = new FileInputStream(file); FileOutputStream fileOutStream = new FileOutputStream(file1); byte[] byteArray = new byte[1024]; int temp = 0; while((temp = fileStream.read(byteArray))!=-1){ fileOutStream.write(byteArray, 0, temp); } fileStream.read(byteArray); fileStream.close(); fileOutStream.close(); } } class ReadThread extends Thread{ public void run() { while(true){ List<String> readList = Test.printfFile(Test.readFileName); for(String str : readList){ if(Test.fileMap.containsKey(str)){ continue; } else Test.fileMap.put(str, str); } try { Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } } } }class WriteThread extends Thread{ public void run() { while(true){ try { Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } List<String> writeList =Test.printfFile(Test.writeFileName); for(Iterator it = Test.fileMap.keySet().iterator();it.hasNext();){ String key = (String)it.next(); boolean flag = false; for(String str : writeList){ if(str.equalsIgnoreCase(key)){ flag = true; break; } } if(!flag){ try { Test.copyFile(Test.readFileName + File.separator + key,Test.writeFileName + File.separator + key); } catch (IOException e) { e.printStackTrace(); } } } } }}
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基本逻辑是这样的，楼主发现问题，或者可以根据自己需求自己改一改。
- Java code
import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.util.HashSet;import java.util.Set;public class FilesListener implements Runnable{ private String fileDir = "d://from"; private String newFileDir = "d://to"; private Set<String> oldFiles = new HashSet<String>(); public FilesListener(){ File[] files = new File(fileDir).listFiles(); if(files != null){ for(File file : files){ oldFiles.add(file.getName()); } } } private Set<String> checkNewFiles(){ Set<String> nowFiles = new HashSet<String>(); File[] files = new File(fileDir).listFiles(); if(files != null){ for(File file : files){ nowFiles.add(file.getName()); } } if(nowFiles.size() > oldFiles.size()){ Set<String> addFiles = new HashSet<String>(); addFiles.addAll(nowFiles); addFiles.removeAll(oldFiles); oldFiles.addAll(addFiles); return addFiles; } return null; } private void copyFiles(Set<String> addFiles) { for (String file : addFiles) { try { String oldFileName = fileDir + "//" + file; BufferedInputStream bis = new BufferedInputStream(new FileInputStream(oldFileName)); String newFileName = newFileDir + "//" + file; BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(newFileName)); byte[] buf = new byte[1024]; int read = -1; while((read = bis.read(buf)) > 0){ bos.write(buf,0,read); } bos.close(); bis.close(); System.out.println("复制文件：" + file); } catch (Exception e) { e.printStackTrace(); } } } public void run() { Set<String> addFiles = checkNewFiles(); if (addFiles != null) { copyFiles(addFiles); } try { Thread.sleep(3000); run(); } catch (InterruptedException e) { e.printStackTrace(); } } public static void main(String[] args) { FilesListener fl = new FilesListener(); new Thread(fl).start(); }}