Java数据输入输出流

package com.wkcto.chapter06.filterstream;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * DataInputStream/DataOutputStream
 * 	可以读写带有数据格式的数据
 * 	不直接对数据源进行操作, 是处理流
 * @author 蛙课网
 *
 */
public class Test02 {

	public static void main(String[] args) throws IOException {
		//1) 保存数据
//		writeData();
		
		//2) 读取文件
		readData();
	}

	//使用DataInputStream读取文件的内容
	private static void readData() throws IOException {
		InputStream in = new FileInputStream("d:/def.txt");
		DataInputStream dis = new DataInputStream(in);
		
		//读取的顺序要与写入的顺序一致 
		int num = dis.readInt();
		double dd = dis.readDouble();
		boolean flag = dis.readBoolean();
		String text = dis.readUTF();
		
		dis.close();
		System.out.println("num=" + num + " ,dd=" + dd + " ,flag=" + flag + " ,text=" + text);
	}

	//使用DataOutputStream保存数据
	private static void writeData() throws IOException {
		OutputStream out = new FileOutputStream("d:/def.txt");
		DataOutputStream dos = new DataOutputStream(out);
		
		dos.writeInt(123);				//保存整数
		dos.writeDouble(3.14);			//保存小数
		dos.writeBoolean(true);			//保存布尔
		dos.writeUTF("wkcto");			//保存字符串
		
		dos.close();
	}

}