Interface Implementation and Proxying

class JImplements:
    """Annotation to implement Java interfaces from Python classes.
    
    Modern approach for creating Python implementations of Java interfaces.
    """
    
    def __init__(self, *interfaces, **kwargs):
        """Create interface implementation annotation.
        
        Args:
            *interfaces: Java interface classes to implement
            **kwargs: Additional options like deferred=True
        """

def JOverride(func):
    """Decorator to mark method as overriding Java method.
    
    Used to explicitly mark methods that override or implement
    Java interface methods.
    
    Args:
        func: Python method that overrides Java method
        
    Returns:
        func: The decorated method
    """

class JProxy:
    """Create proxies for Java interfaces (legacy approach).
    
    Note: Deprecated in favor of JImplements annotation.
    """
    
    def __init__(self, interface, inst=None, loader=None, dict=None):
        """Create a proxy for Java interface.
        
        Args:
            interface: Java interface class
            inst: Python instance implementing the interface
            loader: Class loader (optional)
            dict: Method dictionary (optional)
        """

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Get Java interface
Runnable = jpype.java.lang.Runnable
ActionListener = jpype.javax.swing.event.ActionListener

# Implement single interface
@JImplements(Runnable)
class MyRunnable:
    def __init__(self, name):
        self.name = name
    
    @JOverride
    def run(self):
        print(f"Running task: {self.name}")

# Create instance and use with Java
task = MyRunnable("background_task")
thread = jpype.java.lang.Thread(task)
thread.start()
thread.join()

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Import required interfaces
Runnable = jpype.java.lang.Runnable
Comparable = jpype.java.lang.Comparable

# Implement multiple interfaces
@JImplements(Runnable, Comparable)
class MultiTask:
    def __init__(self, priority, name):
        self.priority = priority
        self.name = name
    
    @JOverride
    def run(self):
        print(f"Executing task: {self.name} (priority: {self.priority})")
    
    @JOverride
    def compareTo(self, other):
        return self.priority - other.priority

# Use with Java APIs
task1 = MultiTask(1, "high_priority")
task2 = MultiTask(2, "low_priority")

# Sort using Java Collections
tasks = jpype.java.util.ArrayList()
tasks.add(task1)
tasks.add(task2)

jpype.java.util.Collections.sort(tasks)

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# GUI event handling
ActionListener = jpype.javax.swing.event.ActionListener

@JImplements(ActionListener)
class ButtonClickHandler:
    def __init__(self, button_name):
        self.button_name = button_name
    
    @JOverride
    def actionPerformed(self, event):
        print(f"Button clicked: {self.button_name}")
        source = event.getSource()
        print(f"Event source: {source}")

# Use with Swing components
JFrame = jpype.javax.swing.JFrame
JButton = jpype.javax.swing.JButton

frame = JFrame("Test Window")
button = JButton("Click Me")
handler = ButtonClickHandler("test_button")

button.addActionListener(handler)
frame.add(button)
frame.setSize(200, 100)
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
# frame.setVisible(True)  # Uncomment for GUI display

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Custom observer interface implementation
Observer = jpype.java.util.Observer

@JImplements(Observer)
class DataObserver:
    def __init__(self, name):
        self.name = name
    
    @JOverride
    def update(self, observable, arg):
        print(f"Observer {self.name} received update: {arg}")

# Use with Observable
Observable = jpype.java.util.Observable

class DataModel(jpype.java.util.Observable):
    def __init__(self):
        super().__init__()
        self.data = ""
    
    def set_data(self, data):
        self.data = data
        self.setChanged()
        self.notifyObservers(data)

# Set up observer pattern
model = DataModel()
observer1 = DataObserver("console_logger")
observer2 = DataObserver("file_logger")

model.addObserver(observer1)
model.addObserver(observer2)

model.set_data("New data arrived")

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Deferred implementation (loaded after JVM starts)
@JImplements("java.lang.Runnable", deferred=True)
class DeferredTask:
    def __init__(self, message):
        self.message = message
    
    @JOverride
    def run(self):
        print(f"Deferred task: {self.message}")

# Use normally
task = DeferredTask("delayed_initialization")
thread = jpype.java.lang.Thread(task)
thread.start()
thread.join()

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

Callable = jpype.java.util.concurrent.Callable

@JImplements(Callable)
class RiskyTask:
    def __init__(self, should_fail=False):
        self.should_fail = should_fail
    
    @JOverride
    def call(self):
        if self.should_fail:
            # Raise Java exception from Python
            raise jpype.java.lang.RuntimeException("Task failed!")
        return "Task completed successfully"

# Use with ExecutorService
ExecutorService = jpype.java.util.concurrent.Executors.newSingleThreadExecutor()

# Successful task
success_task = RiskyTask(False)
future1 = ExecutorService.submit(success_task)
print(future1.get())  # "Task completed successfully"

# Failing task
fail_task = RiskyTask(True)
future2 = ExecutorService.submit(fail_task)

try:
    result = future2.get()
except jpype.java.util.concurrent.ExecutionException as e:
    print(f"Task failed with: {e.getCause()}")

ExecutorService.shutdown()
jpype.shutdownJVM()

import jpype

jpype.startJVM()

# Legacy proxy approach (not recommended)
Runnable = jpype.java.lang.Runnable

class LegacyTask:
    def run(self):
        print("Legacy task running")

# Create proxy (deprecated approach)
task_instance = LegacyTask()
proxy = jpype.JProxy(Runnable, inst=task_instance)

thread = jpype.java.lang.Thread(proxy)
thread.start()
thread.join()

jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Handle method name conflicts with Python keywords
ActionListener = jpype.javax.swing.event.ActionListener

@JImplements(ActionListener)
class KeywordHandler:
    @JOverride
    def actionPerformed(self, event):
        # Python method name maps to Java actionPerformed
        print("Action performed")

# Explicit method mapping for complex cases
Comparator = jpype.java.util.Comparator

@JImplements(Comparator)
class CustomComparator:
    @JOverride
    def compare(self, o1, o2):
        # Compare based on string representation
        s1 = str(o1)
        s2 = str(o2)
        if s1 < s2:
            return -1
        elif s1 > s2:
            return 1
        else:
            return 0
    
    @JOverride
    def equals(self, other):
        return self is other

jpype.shutdownJVM()