FileOutputStream类创建文件，并写入数据。

package com.within;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class TestFileOutputStream {

	public static void main(String[] args) {
		String s="sdfsdgfsdogfjusods9df979fgdsf";
		FileOutputStream fos=null;
		FileOutputStream fos1=null;
		
		File f=new File("C:\\Users\\within\\Desktop\\IO流\\IO\\f.txt");
		File f1=new File("C:\\Users\\within\\Desktop\\IO流\\IO\\f1.txt");
		
		if(!f.exists()){
			try {
				f.createNewFile();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(!f1.exists()){
			try {
				f1.createNewFile();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		try {
			fos=new FileOutputStream(f);
			fos1=new FileOutputStream(f1);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		byte[] b=s.getBytes();
		try {
			fos.write(b);
			fos1.write(b,0,s.length()/2);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				if(fos!=null){					
					fos.close();
				}
				if(fos1!=null){					
					fos1.close();
				}
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}