Hot Swap tool understanding

java -Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y Test

jdb -attach 8787

stop in com.example.MyClass.myMethod

cont

step

print myVariable

threads

·       Create A Project give the example hotswaptool

              Add two jar file hotswaptool

                   bcel-5.2.jar (this should be download from google)

                   tools.jar (this is coming from your jdk path like D:\Software\java\jdk1.8.0_05\lib)

·       Copy the below code and add in your source directory.

·       Run this program in java application

·       see the open window.

·       Now java hotswaptool is ready

·       Enabling the Debug Mode in your remote machine project where you put the hot .class file

·       To run a regular serverless Java class Test with debugging enabled in the Oracle HotSpot JVM, you need to use the following command:

java -Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y Test

·       Start the server and call api.

·       If you need any business changes .class file in remote machine without restart your server goto below step

·       Go to your local machine and change the business logic and compile

·       Run the hot swap tool

·       Give the remote machine IP address

·       Give the remote machine debug port number like 8787

·       Browse the .class file from your local

·       Click the hotswap

·       Done

·       Again call api see the result it will effected

package com.kartik.org;

import javax.swing.JFrame;

/**

 *

 * @author kmandal

 *

 */

public class SwapDemo {

 public static void main(String[] a) {

  Swap frame = new Swap();

  frame.setTitle("Hot Swap Tool");

  frame.setVisible(true);

  frame.setBounds(10, 10, 500, 500);

  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  frame.setResizable(false);

  frame.setLocationRelativeTo(null);

 }

}

package com.kartik.org;

import java.awt.Container;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.FocusEvent;

import java.awt.event.FocusListener;

import java.awt.event.KeyAdapter;

import java.awt.event.KeyEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.io.File;

import java.io.IOException;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JTextField;

import javax.swing.SwingUtilities;

import org.apache.bcel.classfile.ClassParser;

import org.apache.bcel.classfile.JavaClass;

/**

 *

 * @author kmandal

 *

 */

public class Swap extends JFrame implements ActionListener,Runnable {

 private static final long serialVersionUID = 1L;

 private String ipAddress;

 private String portNumber;

 private String absoulatePath;

 private String realPath;

 private File file;

    public String getIpAddress() {

  return ipAddress;

 }

 public void setIpAddress(String ipAddress) {

  this.ipAddress = ipAddress;

 }

 public String getPortNumber() {

  return portNumber;

 }

 public void setPortNumber(String portNumber) {

  this.portNumber = portNumber;

 }

 public String getAbsoulatePath() {

  return absoulatePath;

 }

 public void setAbsoulatePath(String absoulatePath) {

  this.absoulatePath = absoulatePath;

 }

 public String getRealPath() {

  return realPath;

 }

 public void setRealPath(String realPath) {

  this.realPath = realPath;

 }

 public File getFile() {

  return file;

 }

 public void setFile(File file) {

  this.file = file;

 }

 Container container=getContentPane();

    //JPanel panel = new JPanel(new GridLayout(0, 1));

 JButton headerLabel=new JButton("Swap Tool ");

    JLabel ipLabel=new JLabel("Ip Address: *");

    JLabel portNoLabel=new JLabel("Port number: *");

    JLabel fileChooseLabel=new JLabel("Choose File: *");

    JTextField ipTextField=new JTextField();

    JTextField portTextField=new JTextField();

    JTextField fileName = new JTextField();

    JButton browse = new JButton("Browse");

    JButton loginButton=new JButton("Swap File");

    JButton resetButton=new JButton("Re-set");

    Swap()

    {

       //Calling methods inside constructor.

        setLayoutManager();

        setLocationAndSize();

        addComponentsToContainer();

    }

   public void setLayoutManager()

   {

       container.setLayout(null);

   }

   public void setLocationAndSize()

   {

    headerLabel.setBounds(50,100,430,30);

    headerLabel.setOpaque(true);

   // headerLabel.setBackground(Color.GREEN);

       //Setting location and Size of each components using setBounds() method.

       ipLabel.setBounds(50,150,100,20);

       portNoLabel.setBounds(50,200,100,20);

       fileChooseLabel.setBounds(50,250,100,20);

       ipTextField.setBounds(150,150,200,20);

       portTextField.setBounds(150,200,100,20);

       fileName.setEditable(false);

       fileName.setBounds(150,250,220,20);

       browse.setBounds(380,250,100,20);

       loginButton.setBounds(50,300,100,25);

       resetButton.setBounds(200,300,100,25);

   }

   public void addComponentsToContainer()

   {

    container.add(headerLabel);

      //Adding each components to the Container

       container.add(ipLabel);

       container.add(portNoLabel);

       container.add(fileChooseLabel);

       ipTextField.addFocusListener(new FocusListener() {

   public void focusLost(FocusEvent fe) {

    setIpAddress(ipTextField.getText());

   }

   public void focusGained(FocusEvent fe) {

   }

  });

       ipTextField.addKeyListener(new KeyAdapter() {

   public void keyTyped(KeyEvent e) {

    if (ipTextField.getText().length() >= 50)

     e.consume();

   }

  });

       container.add(ipTextField);

       portTextField.addFocusListener(new FocusListener() {

   public void focusLost(FocusEvent fe) {

    setPortNumber(portTextField.getText());

   }

   public void focusGained(FocusEvent fe) {

   }

  });

       portTextField.addKeyListener(new KeyAdapter() {

   public void keyTyped(KeyEvent e) {

    char letter = e.getKeyChar();

    if (portTextField.getText().length() >= 15) {

     e.consume();

    } else if (!Character.isDigit(letter)) {

     e.consume();

    }

   }

  });

       container.add(portTextField);

       container.add(fileName);

       browse.addMouseListener(new MouseAdapter() {

   public void mouseClicked(MouseEvent evt) {

    if (SwingUtilities.isLeftMouseButton(evt)) {

     Chooser frame = new Chooser();

     fileName.setText(frame.fileName);

     setRealPath(frame.fileName);

     setFile(frame.file);

    }

   }

  });

       container.add(browse);

       loginButton.addMouseListener(new MouseAdapter() {

   public void mouseClicked(MouseEvent evt) {

    if (SwingUtilities.isLeftMouseButton(evt)) {

     boolean flag=validation();

     if(flag){

      /*Thread swapThread = new Thread();

            swapThread.start();

            try {

             System.out.println("Start the First Sleep");

             Thread.sleep(5000);

             System.out.println("Start the hot swap");*/

             hotSwap();

             /*System.out.println("Start the Second Sleep");

                Thread.sleep(5000);

                System.out.println("End the sleep");

            } catch (InterruptedException e) {

                e.printStackTrace();

            }*/

     }

    }

   }

  });

       container.add(loginButton);

       container.add(resetButton);

   }

   /**

  *

  * @param fullStr

  * @return

  */

 private void hotSwap() {

  StringBuffer br = new StringBuffer();

  generateComand(br);

  String command = br.toString();

  System.out.println(command);

  StringBuffer br2 = new StringBuffer();

  String packageName = null;

  File f = getFile();

  String aa = f.getName();

  String[] arrOfStr = aa.split("\\.", -1);

  String filePath = filePathMethod(getRealPath());

  if (f.exists()) {

   ClassParser classParser = null;

   try {

    classParser = new ClassParser(filePath);

   } catch (IOException e) {

    e.printStackTrace();

   }

   JavaClass javaClass = null;

   try {

    javaClass = classParser.parse();

   } catch (IOException ioe) {

    System.out.println(filePath);

   }

   packageName = javaClass.getPackageName();

   writeMethodInCommand(br2, packageName, arrOfStr, filePath);

   HotSwap h = new HotSwap();

   boolean isRunning = h.isProcessRunning(command,

     br2.toString());

   String processName = "java.exe";

   if (isRunning) {

    h.killProcess(processName);

   } else {

    System.out.println("Not able to find the process : "

      + processName);

   }

  } else {

   System.out.println("\nFile Path not exist ");

  }

 }

 /**

  * This is find out the absoluteFilePath of a file for any server

  *

  * @param fileName

  *            fileName

  * @param pathName

  *            pathName

  * @return absoluteFilePath

  */

 public String filePathMethod(String pathName) {

  String absoluteFilePath = "";

  // String workingDir = System.getProperty("user.dir");

  String runnigServerOs = System.getProperty("os.name").toLowerCase();

  if (runnigServerOs.indexOf("win") >= 0) {

   // if windows

   absoluteFilePath = pathName.replaceAll("\\\\", "\\\\\\\\");

  } else if (runnigServerOs.indexOf("nix") >= 0

    || runnigServerOs.indexOf("nux") >= 0

    || runnigServerOs.indexOf("mac") >= 0) {

   // if unix or mac

   // absoluteFilePath = workingDir + "/" + fileName;

   absoluteFilePath = pathName;

  } else {

   // unknow os?

   // absoluteFilePath = workingDir + "/" + fileName;

   absoluteFilePath = pathName;

  }

  System.out.println("Final filepath : " + absoluteFilePath);

  return absoluteFilePath;

 }

 /**

  *

  * @param br

  */

 private void generateComand(StringBuffer br) {

  br.append("jdb -connect com.sun.jdi.SocketAttach:hostname=");

  br.append(getIpAddress());

  br.append(",port=");

  br.append(getPortNumber());

 }

 /**

  *

  * @param br2

  * @param packageName

  * @param arrOfStr

  * @param filePath

  */

 private void writeMethodInCommand(StringBuffer br2,

   String packageName, String[] arrOfStr, String filePath) {

  br2.append("redefine");

  br2.append(" ");

  br2.append(packageName);

  br2.append(".");

  br2.append(arrOfStr[0]);

  br2.append(" ");

  br2.append(filePath);

 }

    @Override

    public void actionPerformed(ActionEvent e) {

    }

    public boolean validation() {

     if(getIpAddress().equals(""))

     {

      String message = "Please enter ip address properly\n";

          JOptionPane.showMessageDialog(container, message, "Dialog",

              JOptionPane.ERROR_MESSAGE);

          return false;

     }

     else if(getPortNumber().equals(""))

     {

      String message = "Please enter port number\n";

      JOptionPane.showMessageDialog(container, message, "Dialog",

          JOptionPane.ERROR_MESSAGE);

      return false;

     }

     else if(Integer.parseInt(getPortNumber())<=0)

     {

      String message = "Please enter port number\n";

      JOptionPane.showMessageDialog(container, message, "Dialog",

          JOptionPane.ERROR_MESSAGE);

      return false;

     }

     else if(getFile().equals(""))

     {

      String message = "Please enter file which you need to swap \n";

      JOptionPane.showMessageDialog(container, message, "Dialog",

          JOptionPane.ERROR_MESSAGE);

      return false;

     }

  return true;

    }

 @Override

 public void run() {

  // TODO Auto-generated method stub

 }

}

package com.kartik.org;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

public class HotSwap {

 public boolean isProcessRunning(String command,String write) {

  boolean flag=false;

    try {

        /* String array to execute commands */

        String[] commands = new String[3];

        commands[0] = "cmd";

        commands[1] = "/c";

        /* Command you want to execute */

       // command[2] = "jdb -connect com.sun.jdi.SocketAttach:hostname=192.168.211.180,port=8999";

        //commands[2] = "jdb -connect com.sun.jdi.SocketAttach:hostname=192.168.57.66,port=8999";

        commands[2] = command;

        /* Create process */

        Process p = Runtime.getRuntime().exec(commands);

        /* Get OuputStream */

        PrintWriter writer = new PrintWriter(new OutputStreamWriter(new BufferedOutputStream(p.getOutputStream())), true);

        /* Read the output of command prompt */

        BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));

        String line = reader.readLine();

        /* Read upto end of execution */

        int count=0;

        while (line != null) {

            /* Pass the value to command prompt/user input */

           // writer.println("redefine com.journaldev.spring.PersonController  D:\\Kartik\\Karthik\\Spring-Boot-REST\\target\\classes\\com\\journaldev\\spring\\PersonController.class");

            writer.println(write);

            System.out.println(line);

            if(count>=2){

             return true;

            }else{

            line = reader.readLine();

            }

            count=count+1;

        }

        /* The stream obtains data from the standard output stream of the process represented by this Process object. */

        BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

        /* The stream obtains data from the error output stream of the process represented by this Process object. */

        BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));

        String Input;

        while ((Input = stdInput.readLine()) != null) {

            System.out.println(Input);

        }           

        String Error;

        while ((Error = stdError.readLine()) != null) {

            System.out.println(Error);

        }

    } catch (Exception e) {

        e.printStackTrace();

    }

 return flag;

}

 private static final String KILL = "TASKKILL /F /IM ";

 public void killProcess(String serviceName) {

  try {

   Runtime.getRuntime().exec(KILL + serviceName);

   System.out.println(serviceName+" killed successfully!");

   System.exit(0);

  } catch (IOException e) {

   e.printStackTrace();

  }

 }

}

package com.kartik.org;

import java.io.File;

import javax.swing.JFileChooser;

import javax.swing.JFrame;

/**

 *

 * @author kmandal

 *

 */

public class Chooser extends JFrame {

 private static final long serialVersionUID = 1L;

 public JFileChooser chooser;

 public String fileName;

 public File file;

 public Chooser() {

  chooser = new JFileChooser();

  int r = chooser.showOpenDialog(new JFrame());

  if (r == JFileChooser.APPROVE_OPTION) {

   fileName = chooser.getSelectedFile().getPath();

   file = chooser.getSelectedFile();

  }

 }

}