文件輸入流小程序

import java.io.*;
public class TestFileInputString {
	public static void main(String[] args) {
		FileInputStream in = null;
		int b=0;
		try{
		in = new FileInputStream("d:/TestFileInputStream.java");
		}catch(FileNotFoundException f){
				System.out.println("未找到文件！");
			}
			long num = 0;
			try{
			while((b = in.read())!=-1){
				System.out.print((char)b);
				num++;
			}
			in.close();
			System.out.println();
			System.out.println("共讀取了" + num + "個字符");
		}catch(IOException e){
			System.out.println("文件讀取異常！");
			
		}	
	}
}

下面看一個輸入輸出流的程序

import java.io.*;
public class TestFileOutputStream{
	public static void main(String[] args) {
		int b = 0;
//		FileInputStream in = null;
//		FileOutputStream out = null;
		
		try{
			FileInputStream in = new FileInputStream("d:/java/HelloWorld.java");
			FileOutputStream out = new FileOutputStream("d:/java/JW.java");
			while((b=in.read())!=-1){
				out.write(b);
			}
			
			in.close();
			out.close();
		}catch(FileNotFoundException e2){
			System.out.println("未找到文件！");
		}catch(IOException e1){
			System.out.println("文件複製錯誤！");	
		}
		System.out.println("文件複製成功！");
	}
}

這兩個程序有着嚴重的問題，因爲JDK文檔所訴，FileInputStream和FileOutputStream這兩個類只能對每個字符進行讀取，因此讀不出來漢子的，所以要使用FileReader和FileWrite