how to read and show a byte array?

[Tran Tuan Hung]

OK I have a file following:

9:10:05;Long Message;
030000002f130200000000000800450000800000000001119f7a0a000000e0e02f13c5dac5da006c0000000000000303000000000
 
00400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 
000000000000000000000000000000000000000000000000000000000000000000000000000;
9:15:58;Sort Message;
0300000032330200000000000800450000800000000001119c5a0a000000e0e03233c5dac5da006c000000000000030300000000
 
00040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 
0000000000000000000000000000000000000000000000000000000000000000000000000000

I want to read it and show in the console, so i have made following.
Here is Message bean class to store data.

 
public class Message {
private String frmTime;
private String typeMsg;
private byte[] data;
 
public Message(String _frmTime, String _typeMsg, byte[] _data) {
// TODO Auto-generated constructor stub
this.frmTime = _frmTime;
this.typeMsg = _typeMsg;
// this.data = new byte[1024];//
}
 
public Message() {
frmTime = "hh:mm:ss";
typeMsg = "";
data = new byte[1024];
}
 
public String getFrmTime() {
return frmTime;
}
 
public void setFrmTime(String frmTime) {
this.frmTime = frmTime;
}
 
public String getTypeMsg() {
return typeMsg;
}
 
public void setTypeMsg(String typeMsg) {
this.typeMsg = typeMsg;
}
 
public byte[] getData() {
return data;
}
 
public void setData(byte[] data) {
this.data = data;
}
 
public String toString() {
return frmTime + " " + typeMsg + " " + data + " ";
}
 
}
 

And here is main class to Test.

import java.io.BufferedReader;
import java.io.FileReader;
 
public class TestMsg {
private String filePath;
 
public void readFileMsg(Message msg, String filePath) {
String line = null;
try {
FileReader inputFile = new FileReader(filePath);
BufferedReader in = new BufferedReader(inputFile);
while ((line = in.readLine()) != null) {
String[] info = line.split(";");
msg.setFrmTime(info[0]);
msg.setTypeMsg(info[1]);
// msg.setData()
System.out.println(msg.toString());
}
} catch (Exception e) {
// TODO: handle exception
// e.printStackTrace();
}
 
}
 
public static void main(String[] args) {
Message msg = new Message();
TestMsg testMsg = new TestMsg();
testMsg.readFileMsg(msg, "C://Message.txt");
}
 
}

Here is result in the console of eclipse.

9:10:05 Long Message [B@19821f
9:13:58 Short Message [B@601bb1

I have got frmTime (9:10:05) and typeMsg (Long Message)but i dont know how to get the byte array (data) ?

Suggset me please!!!
Thanks and best regards.
[ November 07, 2007: Message edited by: Bear Bibeault ]

[Jim Yingst]

I'm guessing that strings like

030000002f130200000000000800450000800000000001119f7a0a000000e0e02f13c5dac5da006c0000000000000303000000000

are in hexadecimal (since I see digits and letters in the range a=f, but nothing else). Are you familiar with hexadecimal? Each character 0-9 or a-F corresponds to a 4 bits, so every two characters correspond to a single byte (8 bits). You will need to write some methods to read and write byte arrays in hexadecimal here. There are some existing methods that may help you, but you'll need to do some looping.

To read, try something like this:

create a byte[] array with size equal to half the length of the string.
for every two characters in the string {
    convert those two characters into a single byte
    set the next element in the array to that byte
}

You may find the Integer.parseInt() method useful here. Be sure to look a the overloaded versions of this method.

And to write:

for every byte in the array {
    convert the byte to a 2-character string, and write it
}

If you're using JDK 5 or later, you can accomplish this simply using String.format() or System.out.format(). If not, you may need to do somethign like this:

for every byte in the array {
    convert the first 4 bits to a single character, and write it
    convert the last 4 bits to a single character, and write it
}

If you can't use String.format(), this will require a little bit of simple math. Remember that every character has a numeric value - you can see a table here.

[Tran Tuan Hung]

Jim Yingst , thanks you very much,
But to be honest, i understand the aglothirm you suggest me but i am still not yet how to got it exactly in my code. I still code incorrect you can correct me by the way you can give me an example or a snippe code?
I am very sorry for my stupid.
thanks and best regards,
Hung

[Quang Pham]

Hi Hung
It should work by changing your code like this:
while ((line = in.readLine()) != null) {String[] info = line.split(";");msg.setFrmTime(info[0]);msg.setTypeMsg(info[1]);
msg.setData(info[1].getBytes()); <-----------------
System.out.println(msg.toString());
}
But it seem like your data contains a bunch of PACK fields. To understand your data is another story.
Quang

[Tran Tuan Hung]

Thanks Quang, i also edit the code following:

 
String[] info = line.split(";");
msg.setFrmTime(info[0]);
msg.setTypeMsg(info[1]);
msg.setData(info[2].getBytes());
System.out.println(msg.toString());   

but it throw an exception follow:

java.lang.ArrayIndexOutOfBoundsException: 2
at test.TestMsg.readFileMsg(TestMsg.java:18)
at test.TestMsg.main(TestMsg.java:31)

I searched and think to slove this problem, but i still not yet modyfiy my code. With Jim Yingst's solution i still try to code but it still thrown exception and i can not ...
[ November 07, 2007: Message edited by: Tran Tuan Hung ]

[Quang Pham]

Hi Hung
You can only store 1 frmTime, 1 typeMsg and 1 byte[] data per instance Message. I've shorten your data and modified the source code as follow and it works.
import java.io.BufferedReader;
import java.io.FileReader;
public class TestMessage {
private String filePath;
public void readFileMsg(Message msg) {
String line = null;
try {
String[] info = {"9:10:05","Long Message","030000002f130200000000000800450000800000000001119f7a0a000000e0e02f13c5dac5da006c0000000000000303000000000 00400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000000000000000000000000000000000000000000000000000"};
msg.setFrmTime(info[0]);
msg.setTypeMsg(info[1]);
msg.setData(info[2].getBytes());
System.out.println(msg.getFrmTime());
System.out.println(msg.getTypeMsg());
byte b [] = msg.getData();
for (int i=0;i< b.length;i++){
char c = (char)b[i];
System.out.print(c);
}
} catch (Exception e) { // TODO: handle exception//
e.printStackTrace();
}
}
public static void main(String[] args) {
Message msg = new Message();
TestMessage testMsg = new TestMessage();
testMsg.readFileMsg(msg);
}
}

[Tran Tuan Hung]

I would like to get data from the text file, but BTW i also sloved my problem.
Thanks for helping me Jim Yingst and Quang.