将一个文件从一个文件夹拷贝到另一个文件夹的java代码

package cn.zby.test;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import org.junit.Test;

public class TestDemo1 {
	@Test
	public void demo1() throws Exception{
		FileInputStream fis = new FileInputStream("F:/test/邓小平时代.pdf");
		FileOutputStream fos = new FileOutputStream("F:/test/result/邓小平时代.pdf");
		int len = 0;
		byte[] buf = new byte[1024];
		while ((len = fis.read(buf)) != -1) {
			fos.write(buf, 0, len);
		}
		fos.close();
		fis.close();
	}
	
	@Test
	public void demo2() throws Exception{
		FileInputStream fis = new FileInputStream("F:/test/邓小平时代.pdf");
		BufferedInputStream bufferedInputStream = new BufferedInputStream(fis);
		FileOutputStream fos = new FileOutputStream("F:/test/result/邓小平时代.pdf");
		BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fos);
		int len = 0;
		while ((len = bufferedInputStream.read()) != -1) {
			bufferedOutputStream.write(len);
		}
		bufferedOutputStream.close();
		bufferedInputStream.close();
	}
	//---------不建议使用的两种-----------------------------------------------------
	@Test
	public void demo3() throws Exception{//需要创建数组，如果文件过大，创建数组花费时间太长
		FileInputStream fis = new FileInputStream("F:/test/邓小平时代.pdf");
		FileOutputStream fos = new FileOutputStream("F:/test/result/邓小平时代.pdf");
		byte[] buf = new byte[fis.available()]; 
		fis.read(buf); 
		fos.write(buf);
		fos.close();
		fis.close();
	}
	
	@Test
	public void demo4() throws Exception{//没有缓冲区的效率很慢的
		FileInputStream fis = new FileInputStream("F:/test/邓小平时代.pdf");
		FileOutputStream fos = new FileOutputStream("F:/test/result/邓小平时代.pdf");
		int len = 0;
		while ((len = fis.read()) != -1) {
			fos.write(len);
		}
		fos.close();
		fis.close();
	}
	
	
}

参考：百度知道