Java 流的几个简单的例子

package step2_io;

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

/**
 * 
 * @author 
 *
 *这只能测试字节流,所以文件中有中文字的时候,是输出不来的哦!
 */
public class TestFileInputStream {
	
	public static void main(String[] args) {
		int b;
		FileInputStream fis = null;
	
		/*
		//(1) 建立读取文件的流
		try {
	     fis = new FileInputStream("D:\\Experiment\\eclipse\\TestIo.txt");
		} catch (FileNotFoundException e) {
			
			e.printStackTrace();
		}
		
		//(2)把文件的内容读进来,在控制台上写出来
		try {
			while((b=fis.read())!=-1) {
				System.out.print((char)b);
			}
		} catch (IOException e) {
			
			e.printStackTrace();
		}
		//(3)把文件流关闭上
		
		try {
			fis.close();
		} catch (IOException e) {
			
			e.printStackTrace();
		}
		*/
		
		//以上的方法都是用Print来输出内容
		
		//我们在这里尝试用FileOutputStream来做实验
		//把TestIo这文件的内容读入到程序里,程序把它写出到test.txt文件中!!
		FileOutputStream fos = null;
		
		 try {
			fis = new FileInputStream("D:\\Experiment\\eclipse\\TestIo.txt");
			fos = new FileOutputStream("D:\\Experiment\\eclipse\\test.txt");
			while((b=fis.read())!=-1) {
				fos.write(b);
			}
		} catch (Exception e) {			
			e.printStackTrace();
		}
		
		try {
			fis.close();
			fos.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
			
		}

	}

 

package step2_io;

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

public class TestFileReader {

	public static void main(String[] args) {
		FileReader fr = null;
		//添加FileWriter
		FileWriter fw = null;
		int b;
		
		//(1)把文件读进来
		try {
			fr = new FileReader("D:\\Experiment\\eclipse\\TestIo.txt");
			fw = new FileWriter("D:\\Experiment\\eclipse\\test.txt");
			//(2)把文件的内容写出去
			while((b=fr.read())!=-1) {
			//System.out.print((char)b);
				fw.write((char)b);
			
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		
		//(3)流关闭
		try {
			fr.close();
			fw.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

 

 

 

下面是处理流的缓冲流的例子:

 

package step2_io;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class TestBufferStream {

	public static void main(String[] args) {
	
		int b;
		String s;
		//BufferedInputStream bis = null;
		BufferedReader bis = null;
		try {
			FileReader fis = new FileReader("D:\\Experiment\\eclipse\\TestIo.txt");
			bis = new BufferedReader(fis);
			
//			while((b=bis.read())!= -1) {
//				System.out.print((char)b);
//			}
			while((s=bis.readLine())!=null) {
				System.out.print(s);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		try {
			bis.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

 

public class TestIn {
	public static void main(String[] args) {

		BufferedWriter bw = null;
		String s;
		BufferedReader bf = null;
		PrintWriter pw = null;
		
		try {
			bf = new BufferedReader(new InputStreamReader(System.in));
			bw = new BufferedWriter(new FileWriter("D:\\Experiment\\eclipse\\test.txt"));
		    //pw = new PrintWriter(new BufferedWriter(new FileWriter("D:\\Experiment\\eclipse\\test.txt")));
		} catch (Exception e1) {
			e1.printStackTrace();
		}
		try {
			while((s=bf.readLine())!=null) {
				
				System.out.println("Hey  :" +s);
				System.out.print("\n");
				bw.write(s);
				bw.newLine();
				bw.flush();
			}
			
			bf.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}