import java.awt.Frame;
import java.io.*;


public class filewriter {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws IOException{
		// TODO Auto-generated method stub
		//test1();
		test2();
	}
	static void test1()throws IOException{
		FileWriter fw = new FileWriter("F:\\fd.txt");
		fw.write("sfasf");
		fw.flush();
		fw.write("zzzzz");
		fw.flush();
		fw.close();
		fw = new FileWriter("F:\\fd.txt", true);
		fw.write("cccc");
		fw.flush();
		fw.close();
	}
	static void test2(){
		FileWriter fw = null;
		try {
			fw = new FileWriter("F:\\fd2.txt");
			fw.write("wzz");
		} catch (IOException e) {
			// TODO: handle exception
			System.out.println(e.toString());
		}
		finally{
			try {
				if(fw!=null)
					fw.close();
			} catch (IOException e2) {
				// TODO: handle exception
				System.out.println(e2.toString());
			}
		}
	}
}

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;


public class filereader {

	/**
	 * @param args
	 */
	public static void main(String[] args)throws IOException {
		// TODO Auto-generated method stub
		//test1()
		//test2();
		//test3();
		//test4();
		test5();
	}
	static void test1()throws IOException{
		FileReader fr = new FileReader("F:\\fd.txt");
		int c;
		while((c = fr.read()) != -1){
			System.out.println((char)c);
		}
		fr.close();
	}
	static void test2()throws IOException{
		FileReader fr = new FileReader("F:\\fd.txt");
		char[] buf = new char[3];
		int x;
		while((x = fr.read(buf)) != -1){
			System.out.println(buf);
		}
		fr.close();
	}
	static void test3()throws IOException{
		FileReader fReader = new FileReader("F:\\fd.txt");
		char[] buf = new char[2];
		int x;
		while((x = fReader.read(buf))!= -1){
			System.out.print(new String(buf, 0, x));
		}
	}
	static void test4()throws IOException{
		FileWriter fw = new FileWriter("F:\\fd3.txt");
		FileReader fr = new FileReader("F:\\fd2.txt");
		int x;
		while((x = fr.read())!=-1)
		{
			fw.write(x);
		}
		fw.close();
		fr.close();
	}
	static void test5(){
		FileWriter fw = null;
		FileReader fr = null;
		try {
			fw = new FileWriter("F:\\fd3.txt");
			fr = new FileReader("F:\\fd2.txt");
			int len = 0;
			char[] buf = new char[1024];
			while((len = fr.read(buf)) != -1){
				fw.write(buf, 0, len);
			}
		} catch (Exception e) {
			// TODO: handle exception
			System.out.println(e.toString());
		}
		finally{
			try {
				if(fw != null)
					fw.close();
			} catch (IOException e2) {
				// TODO: handle exception
				System.out.println(e2.toString());
			}
			try {
				if(fr!=null)
					fr.close();
			} catch (IOException e2) {
				// TODO: handle exception
				System.out.println(e2.toString());
			}
		}
	}
}

FileWriter FileReader 文本的续写 文本的读取 文本的拷贝