Step 1>Create A Project give the example hotswaptool
Add two jar file hotswaptool
1>bcel-5.2.jar (this should be download from google)
2>tools.jar (this is coming from your jdk path like D:\Software\java\jdk1.8.0_05\lib)
Step 2>Copy the below code and add in your source directory.
Step 3>Run this program in java application
Step 4>see the open window.
Step 5>Now java hotswaptool is ready
Step 6>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
Step 7>Start the server and call api.
Step 8>If you need any business changes .class file in remote machine without restart your server goto below step
Step 1>Go to your local machine and change the business logic and compile
Step 2>Run the hot swap tool
step 3>give the remote machine IP address
step 4>give the remote machine debug port number like 8787
Step 5>browse the .class file from your local
Step 6>Click the hotswap
Step 7>Done
Step 8>again call api see the result it will effected
Step 9>Draw back of the jdb.
Which is working
1>Simple variable --working
2>Existing static variable with out changes --working
3>Existing method change business logic --working
4>Existing static method change business logic --working
5>Existing inner class changes business logic --working
6>Existing inner class business logic --working
Which is not working
1>Existing static variable with value changes --Not working
2>new method add --Not working
3>New static method --Not working
4>add new Enum --Not working
5>existing new enum change business value --Not working
6>add inner class --Not working
7>add new class --Not working
Step 10>Suggestion from my understanding
1>Please add all .java a default serialization id. for avoid the compiler to compiler no new serialization id createion.
Step 11>Thanks for your time spent :)
For more understanding : click
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();
}
}
}
I am Kartik Chandra Mandal from Bangalore, India. Working as software engineer in Java technology. Have good knowledge of OWASP and CSRF in security for applications and it's implementation in Java technology.