Re: about java socket - Java Discussion Boards

I have this code in which I have

Java

JTabbedPane tabbedPane = new JTabbedPane();

and I have

Java

JScrollPane scroll_pane = new JScrollPane(tabbedPane);

But when the JFrame shows up it is blank and after I click the maximize (Window) button it shows up the content on the frame.

why is this happening?

Java

frame.setPreferredSize(new Dimension(1500, 1210));		
        
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.pack();
        frame.setResizable(true);
        frame.setVisible(true);

To add anything in scrollPane , try this

Java

jscrollpane.setViewPortView(...)

Regards
Shubhashish

how to write the output into a text file,i read file using scanner but i dont know anything about how to write into a txt file

See http://docs.oracle.com/javase/tutorial/essential/io/index.html[^].

Veni, vidi, abiit domum

BufferedWriter bw = new BufferedWriter(new FileWriter("./file.txt"));
Then use bw to write your data by invoking it's methods.

In the TCP - "EchoServer" procedure based on the contents of the transmission changes. The principle of transfer from the Client to Server string to transmit a data structure in C language, as follows:
Requirements once the transfer is complete.
struct {
      int devType;
      int opType;
      int opChannel;
      int opVolume;
} Mt_drv;

As a guess the actual question is basically...

You have an existing C\C++ service that use TCP to return the structure that you posted. And you want to write java to do it.

The basics steps.
1. Figure out if the server is big endian or little endian.
2. Learn basic java
3. Learn java sockets.
4. Implement a java client socket.
5. Call the server and get the result.
- Parse the result based on 1.

You might want to verify that you don't need to send anything.

it is implemented on the basis of the code
package socket_tcp;

import java.io.*;
import java.net.*;

public class jTcpCliOnly {
public static void main(String[] args) throws IOException {
Socket echoSocket = null;
PrintWriter out = null;
BufferedReader in = null;
String hostName = new String("hp-HP"); //Your: [XXXXXX] to get

try {
echoSocket = new Socket(hostName, 7000);
out = new PrintWriter(echoSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: " + hostName);
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for " + "the connection to: " + hostName);
System.exit(1);
}

BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
String userInput;
while ((userInput = stdIn.readLine()) != null) {
out.println(userInput); //write what user input to TCP server
System.out.println("echo: " + in.readLine());
}
out.close();
in.close();
stdIn.close();
echoSocket.close();
}

}
___________________________________________________________-
package socket_tcp;

import java.io.*;
import java.net.*;

public class jTcpSerOnly {
public static void main(String[] args) throws IOException {
boolean flag = true;
ServerSocket serverSocket = null;
Socket clientSocket = null;
String inputLine;
BufferedReader is = null;
PrintWriter os = null;

try {
serverSocket = new ServerSocket(7000);
System.out.println("Server listen on: " + serverSocket.getLocalPort());

while (flag) {
clientSocket = serverSocket.accept();
is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
os = new PrintWriter(clientSocket.getOutputStream(), true);
while ((inputLine = is.readLine()) != null) {
if (inputLine.equals("Stop!")) {
flag = false;
break;
}
System.out.println("Server: " + inputLine);
os.println(inputLine);
os.flush();
}
os.close();
is.close();
clientSocket.close();
}
} catch (IOException e) {
System.err.println("Exception: " + e);
}
}

}

i just want to use java socket implementation sends a c struct

You just need to send it as a stream of bytes, the same as any other data. Where is this structure coming from?

Veni, vidi, abiit domum

VB

This structure needs to define with java

Sorry, but I do not understand what you mean. Java does not have structs, only classes.

Veni, vidi, abiit domum

rualchina wrote:

i just want to use java socket implementation
sends a c struct

Sockets do not send structures. Not in java, not in C, not in C++.

What they send is data. Nothing else. It up to the two ends to decide what the data represents - not the socket.

Your struct is just 4 integers of which you have not explicitly defined the following
- Size of each int.
- Endianess of the int.

After you know that then you do what I already said.

Um......Can somebody please tell me how to transfer an image using TCP/IP protocol?
I kinda know how to transfer a text file or a binary file.But ...I really don't know how to transfer an image Cry | :((

It is kinda important....So,if it isn't too much trouble..I want some explanation too.This is related to my project and I have no idea how to do this.So pretty please Cry | :((

Thanks in advance Smile | :)

P.S.I eed full code because we are doing this in linux(putty) ad some programs work only in command prompt.So....

modified 10-Oct-13 11:34am.

I am amazed how many times this question has come up recently: an image file is just a file, a stream of bytes, the same as all other files. Transferring it from one place to another is exactly the same: read some bytes, send them to the receiver, repeat until all bytes have been transferred.

Member 10328278 wrote:
P.S.I eed full code

Sorry, but that's your job, we don't provide code to order.

Veni, vidi, abiit domum

Upvoted... this has come up a lot, and not sure why someone would downvote since you still did answer the question.

Thanks.

Albert Holguin wrote:
not sure why someone would downvote

Probably because I did not provide the code for him.

Veni, vidi, abiit domum

You need to use an input stream to read the bytes from the image file, and send that through a DataOutputStream/equivalent over the network, to your desired host.

Once the host receives the bytes, save to file with appropriate file extension.

I want to add two Jpanel on my tabbed pane ,one should be in south with buttons,and other should be in north where I have Text fields and Labels.
My problem is that the buttons on container Jpanel is not showing in south.
Here is the code:

Java

public class Mainframe extends JFrame
{	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	JTabbedPane tabbedPane = new JTabbedPane();
    JPanel jp1 = new JPanel();    
    JPanel container = new JPanel();
    JFrame frame = new JFrame("TEST");     
    JButton button1 = new JButton("Button 1");
    JButton button2 = new JButton("Button 2");
    JButton button3 = new JButton("Button 3");
    JButton button4 = new JButton("Button 4");
    JButton button5 = new JButton("Button 5");
	/**
	 * @param args
	 */
	private Mainframe()
	{	
		
		Container contentPane = getContentPane();
		container.setLayout(new FlowLayout());				
		BufferedImage myPicture = null;
		try
		{			
			myPicture = ImageIO.read(new File("FINAL.jpg"));
		} 
		catch (IOException e1)
		{
			
			e1.printStackTrace();
		}		
		
		JLabel lbl = new JLabel(new ImageIcon(myPicture));		
		container.add(lbl);
		container.add(button1);
		container.add(button2);
		container.add(button3);
		container.add(button4);
		container.add(button5);
		jp1.add(container,BorderLayout.SOUTH);
                frame.add(tabbedPane);
		tabbedPane.addTab("First Tab",jp1);	
	frame.setPreferredSize(new Dimension(1500, 1210));

        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.pack();
        frame.setResizable(true);
        frame.setVisible(true);

}
}

It looks as though you have too many containers. Try simplifying your setup by adding one element at a time to see where it's going wrong. Start with the tab, then add a panel to the tab, then a single item to the panel etc.

Veni, vidi, abiit domum

Here is how I see it can be simplified ,and still the problem exists.

Java

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.JTextField;
import javax.swing.UIManager;

public class Mainframe extends JFrame
{	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	JTabbedPane tabbedPane = new JTabbedPane();
    JPanel jp1 = new JPanel();    
    JPanel Firstpanel = new JPanel();
    static JFrame frame = new JFrame("Create Company");    
    JButton button1 = new JButton("Button 1");
    JButton button2 = new JButton("Button 2");
    JButton button3 = new JButton("Button 3");
    JButton button4 = new JButton("Button 4");
    JButton button5 = new JButton("Button 5");
	/**
	 * @param args
	 */
	private Mainframe()
	{	
		
				
		BufferedImage myPicture = null;
		try
		{			
			myPicture = ImageIO.read(new File("FINAL.jpg"));
		} 
		catch (IOException e1)
		{
			
			e1.printStackTrace();
		}		
		
		JLabel lbl = new JLabel(new ImageIcon(myPicture));		
		frame.add(tabbedPane);
		jp1.add(Firstpanel,BorderLayout.SOUTH);
		tabbedPane.addTab("New Employer",jp1);		
		Firstpanel.add(button1);
		Firstpanel.add(button2);
		Firstpanel.add(button3);
		
		}
	public static void main(String[] args) 
	{
		frame.setPreferredSize(new Dimension(1500, 1210));
        
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.pack();
        frame.setResizable(true);
        frame.setVisible(true);
		new Mainframe();
		// TODO Auto-generated method stub

	}

}

I didn't see any layout set against the JPanel jP1.
see this http://docs.oracle.com/javase/7/docs/api/java/awt/BorderLayout.html[^]

Regards
Shubhashish

Yes now I know my mistake,thank you Smile | :)

You need to tell the panel to use a border layout like:

Java

jp1.setLayout(new BorderLayout());
jp1.add(Firstpanel,BorderLayout.SOUTH);
tabbedPane.addTab("New Employer",jp1);
Firstpanel.add(button1);
Firstpanel.add(button2);
Firstpanel.add(button3);

jp1.add(Secondpanel, BorderLayout.NORTH);
Secondpanel.add(button4);
Secondpanel.add(button5);

Veni, vidi, abiit domum

Thank you for your help Smile | :)