package io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

/**
* 数据类型处理流（基本数据类型）
* 输入流：DataInputStream
* 输出流：DataOutputStream
* @author Lenovo
*
*/
public class Demo1 {

public static void main(String[] args) {
    try {
        //dataout("G:/filetext/a.txt");
        //datainput("G:/filetext/a.txt");
        byte[] data=dataout();
        System.out.println(data.length);
        datainput(data);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}
/**
 *从字节数组里读取数据+类型
 * @param str
 * @throws IOException 
 */
public static void datainput(byte[] src) throws IOException {

    DataInputStream inputStream=new DataInputStream(new BufferedInputStream(new ByteArrayInputStream(src)));
    //按顺序输出
    double num1=inputStream.readDouble();
    long num2=inputStream.readLong();
    String string=inputStream.readUTF();
    inputStream.close();
    System.out.println(num1+" "+num2+"\n"+string);
}

/**
 * 数据+类型输出到字节数组里
 * 输出流：新增方法不可使用多态
 * @param str
 * @throws IOException
 */
public static byte[] dataout() throws IOException {
    byte[] bell=null;
    //类型测试
    double point=2.5;
    long lo=100L;
    String string="时间是令人猝不及防的东西";
    //选择流
    ByteArrayOutputStream os=new ByteArrayOutputStream();
    DataOutputStream dataOutputStream=new DataOutputStream(new BufferedOutputStream(os));

    dataOutputStream.writeDouble(point);
    dataOutputStream.writeLong(lo);
    dataOutputStream.writeUTF(string);
    dataOutputStream.flush();
    dataOutputStream.close();
    bell=os.toByteArray();
    os.close();
    return bell;
}

}