如何使用java复制文件呢?

实现思路:
    方式1:使用FileStream
	方式2:使用FileChannel
	方式3:使用ApacheCommonsIO
	方式4:使用FileWriter对象复制文件FileReader读取文件

package com.java265;
 
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
 
import org.apache.commons.io.FileUtils;
 
public class fileUtill {
 
	public static void main(String[] args) {
		 File source = new File("D:/test/sourceFile.txt");  
		 File dest = new File("D:/test/targetFile.txt");  
		try {
			copyFileUsingFileStreams(source,dest);
			copyFileUsingFileChannels(source,dest);
			copyFileUsingApacheCommonsIO(source,dest);
			copyFileUsingJava7Files(source,dest);
		} catch (IOException e) { 
			e.printStackTrace();
		}
 
		
	}
	//使用FileStreams复制
	private static void copyFileUsingFileStreams(File source, File dest)
	        throws IOException {
	    InputStream input = null;
	    OutputStream output = null;
	    try {
	           input = new FileInputStream(source);
	           output = new FileOutputStream(dest);
	           byte[] buf = new byte[1024];
	           int bytesRead;
	           while ((bytesRead = input.read(buf)) != -1) {
	               output.write(buf, 0, bytesRead);
	           }
	    } finally {
	        input.close();
	        output.close();
	    }
	}
	
	//使用FileInputStream/FileOutputStream字节流进行文件的复制操作
	private static void copyFileUsingFileChannels(File source, File dest) throws IOException {
        FileChannel inputChannel = null;
        FileChannel outputChannel = null;
	    try {
	        inputChannel = new FileInputStream(source).getChannel();
	        outputChannel = new FileOutputStream(dest).getChannel();
	        outputChannel.transferFrom(inputChannel, 0, inputChannel.size());
	    } finally {
	        inputChannel.close();
	        outputChannel.close();
	    }
	}
	
	//使用Commons IO复制
	private static void copyFileUsingApacheCommonsIO(File source, File dest)
	         throws IOException {
	     FileUtils.copyFile(source, dest);
	 }
	//使用Java7的Files类复制
	private static void copyFileUsingJava7Files(File source, File dest)
            throws IOException {
        Files.copy(source.toPath(), dest.toPath());
    }
	
	/**
	 * 利用字节流复制
	 * 使用BufferedInputStream/BufferedOutputStream高效字节流进行复制文件
	 */
	 public static void copy(String source,String dest) throws IOException{
		 InputStream is = new BufferedInputStream(new FileInputStream(source));
		 OutputStream os = new BufferedOutputStream(new FileOutputStream(dest));
		 //文件拷贝u，-- 循环+读取+写出
		 byte[] b = new byte[1024];//缓冲大小
		 int len = 0;//接收长度
		 //读取文件
		 while (-1!=(len = is.read(b))) {
		  //读入多少，写出多少，直到读完为止。
		  os.write(b,0,len);
		 }
		 //强制刷出数据
		 os.flush();
		 //关闭流，先开后关
		 os.close();
		 is.close();
	 }
	  
	 /**
	 * 字符流复制
	 * 使用BufferedReader/BufferedWriter高效字符流进行文件复制
	 * 注意这种方式只能复制只包含字符的文件
	 * 也就意味着你用记事本打开该文件你能够读懂
	 */
	 public static void copy1(String source,String dest) throws IOException{
		 //字符输入流
		 BufferedReader reader = new BufferedReader(new FileReader(source));
		 //字符输出流
		 BufferedWriter writer = new BufferedWriter(new FileWriter(dest));
		 char[] cbuf = new char[1024];
		 int len = 0;
		 //边读入边写出
		 while ((len = reader.read(cbuf)) != -1) {
		  writer.write(cbuf, 0, len);
		 }
		 //关闭流
		 writer.close();
		 reader.close();
	}
	 //使用FileReader/FileWriter字符流进行文件复制
	 //注意这种方式只能复制只包含字符的文件,也就意味着你用记事本打开该文件你能够读懂
	 private static void readerWriterCopyFile(File source, File dest) throws IOException {
		//使用字符流进行文件复制，注意：字符流只能复制只含有汉字的文件
		FileReader fr = new FileReader(source);
		FileWriter fw = new FileWriter(dest);
		Integer by = 0;
		while((by = fr.read()) != -1) {
		 fw.write(by);
		}
 
		fr.close();
		fw.close();
	}
}