java之线程安全的单例类和文件拷贝

Posted 2022-08-26 yunshouhu

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

//java之线程安全的单例类和文件拷贝
public class MyCopyFile 

	private static MyCopyFile instance=null;
	private MyCopyFile()
	
	//线程安全的单例类
	public static MyCopyFile getInstance()
	
		if(instance==null)
		
			synchronized (MyCopyFile.class) 
				if(instance==null)
				
					instance=new MyCopyFile();
				
			
		
		return instance;
	
	public static void main(String[] args) 

		MyCopyFile.getInstance().copyfile("d:/input.txt", "d:/output.txt");
		System.out.println("ok");
		
	

	private static void copyfile(String input, String output) 

		FileInputStream inputStream = null;
		FileOutputStream outputStream = null;

		try 
			inputStream = new FileInputStream(input);
			outputStream = new FileOutputStream(output);
			byte buffer[] = new byte[1024];
			int len = -1;
			while ((len = inputStream.read(buffer)) != -1) 
				outputStream.write(buffer, 0, len);
			
			outputStream.flush();
			outputStream.close();
			inputStream.close();
		 catch (Exception e) 
			e.printStackTrace();

		 finally 
			if (inputStream != null) 
				try 
					inputStream.close();
				 catch (IOException e) 
					e.printStackTrace();
				
			
			if (outputStream != null) 
				try 
					outputStream.close();
				 catch (IOException e) 
					e.printStackTrace();