java--基本數據類型及String 與ByteArray的讀寫交互

實現功能：

1.將基本數據類型，如int, long, double, 及String類型數據寫入到 byte[]中，

2.從 byte[]中將數據讀取到 int, long, double, 及String類型變數中

package com.machuang.io.others;

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;

public class DataInteractiveWithByteArray {

    public static void main(String[] args) throws IOException {
        
        byte[] recBytes = writeTypesToBytes();
        readTypesFromBytes(recBytes);
    }
    
    public static void readTypesFromBytes(byte[] srcbytes) throws IOException {
        // 關聯寫出的讀取的 byte[]
        DataInputStream dis = new DataInputStream(
                                    new BufferedInputStream( new ByteArrayInputStream(srcbytes) )
                                                                                            );
        // 讀取操作
        double recDou = dis.readDouble();
        long recL = dis.readLong();
        String recS = dis.readUTF();
        
        dis.close();
        
        
        System.out.println("recDou:\t" + recDou + "\n"
                            + "recL:\t" + recL + "\n"
                            + "recS:\t" + recS);
                
    }
    
    public static byte[] writeTypesToBytes() throws IOException {
        // 要寫出的數據
        double dataDou = 3.6;
        long numL = 100L;
        String dataStr = "architecture";
        
        
        
        // 關聯寫出的 ByteArrayOutputStream
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(
                                    new BufferedOutputStream( bos )
                                                                    );
        dos.writeDouble(dataDou);
        dos.writeLong(numL);
        dos.writeUTF(dataStr);        
        dos.flush();
        
        byte[] dataBytes = bos.toByteArray();

        dos.close();    // 關閉流

        return dataBytes;
        
    }

}

運行結果：