Advanced Features

def synchronized(obj):
    """Create Java monitor lock for with statements.
    
    Args:
        obj: Java object to synchronize on
    
    Returns:
        Context manager for synchronization block
    
    Example:
        with synchronized(java_object):
            # Thread-safe operations
            java_object.modify()
    """

def convertToDirectBuffer(obj):
    """Convert arrays/buffers to Java NIO direct buffers.
    
    Args:
        obj: Python array, bytes, or buffer-like object
    
    Returns:
        Java NIO Buffer: Direct buffer for efficient Java operations
    
    Raises:
        TypeError: If object cannot be converted to buffer
    """

def setupGuiEnvironment(cb):
    """Setup GUI environment for Java Swing/AWT applications.
    
    Args:
        cb: Callback function for GUI setup
    
    Note:
        Darwin/macOS specific functionality
    """

def shutdownGuiEnvironment():
    """Shutdown GUI environment.
    
    Note:
        Darwin/macOS specific functionality
    """

class JImplementationFor:
    """Decorator for registering class implementations for Java types.
    
    Allows Python classes to serve as implementations for Java types.
    """
    
    def __init__(self, classname: str, base: bool = False):
        """Create implementation decorator.
        
        Args:
            classname: Java class name to implement
            base: Whether this is a base implementation
        """

class JConversion:
    """Decorator for registering type conversions.
    
    Allows custom conversion between Python and Java types.
    """
    
    def __init__(self, cls, **kwargs):
        """Create conversion decorator.
        
        Args:
            cls: Target class for conversion
            **kwargs: Additional conversion options
        """

# SQL Type Constants (from jpype.dbapi2)
ARRAY: int
ASCII_STREAM: int
BIGINT: int
BINARY: int
BINARY_STREAM: int  
BIT: int
BLOB: int  
BOOLEAN: int
CHAR: int
CHARACTER_STREAM: int
CLOB: int
DATE: int
DATETIME: int
DECIMAL: int
DISTINCT: int
DOUBLE: int
FLOAT: int
INTEGER: int
JAVA_OBJECT: int
LONGNVARCHAR: int
LONGVARBINARY: int
LONGVARCHAR: int
NCHAR: int
NCHARACTER_STREAM: int
NCLOB: int
NULL: int
NUMBER: int
NUMERIC: int
NVARCHAR: int
OBJECT: int
OTHER: int
REAL: int
REF: int
RESULTSET: int
ROWID: int
SMALLINT: int
SQLXML: int
STRING: int
STRUCT: int
TEXT: int
TIME: int
TIMESTAMP: int
TIMESTAMP_WITH_TIMEZONE: int
TIME_WITH_TIMEZONE: int
TINYINT: int
URL: int
VARBINARY: int
VARCHAR: int

# Additional Database API classes and functions
class Connection: ...
class Cursor: ...
def connect(*args, **kwargs): ...
apilevel: str  # "2.0"
threadsafety: int  # 2
paramstyle: str  # "qmark"

import jpype
import threading
import time

jpype.startJVM()

# Create shared Java object
shared_list = jpype.java.util.ArrayList()

def worker_thread(thread_id):
    """Worker thread that modifies shared Java object safely."""
    for i in range(5):
        # Synchronize access to Java object
        with jpype.synchronized(shared_list):
            current_size = shared_list.size()
            time.sleep(0.01)  # Simulate work
            shared_list.add(f"Thread-{thread_id}-Item-{i}")
            print(f"Thread {thread_id}: Added item, size now {shared_list.size()}")

# Create multiple Python threads
threads = []
for i in range(3):
    thread = threading.Thread(target=worker_thread, args=(i,))
    threads.append(thread)
    thread.start()

# Wait for all threads to complete
for thread in threads:
    thread.join()

print(f"Final list size: {shared_list.size()}")
print("List contents:")
for i in range(shared_list.size()):
    print(f"  {i}: {shared_list.get(i)}")

jpype.shutdownJVM()

import jpype
import array
import numpy as np

jpype.startJVM()

# Convert Python array to Java NIO buffer
python_array = array.array('i', [1, 2, 3, 4, 5])
java_buffer = jpype.convertToDirectBuffer(python_array)

print(f"Buffer type: {java_buffer.getClass().getName()}")
print(f"Buffer capacity: {java_buffer.capacity()}")
print(f"Buffer remaining: {java_buffer.remaining()}")

# Read from buffer
values = []
while java_buffer.hasRemaining():
    values.append(java_buffer.get())
print(f"Buffer contents: {values}")

# Reset buffer position
java_buffer.rewind()

# Use with Java NIO operations
FileChannel = jpype.JClass("java.nio.channels.FileChannel")
# Example: could write buffer to file channel

# Convert NumPy array to buffer (if NumPy available)
try:
    import numpy as np
    numpy_array = np.array([10, 20, 30, 40, 50], dtype=np.int32)
    numpy_buffer = jpype.convertToDirectBuffer(numpy_array)
    print(f"NumPy buffer capacity: {numpy_buffer.capacity()}")
except ImportError:
    print("NumPy not available for buffer conversion example")

jpype.shutdownJVM()

import jpype
from jpype import JImplementationFor, JConversion

jpype.startJVM()

# Custom implementation for Java Iterator
@JImplementationFor("java.util.Iterator")
class PythonListIterator:
    """Python implementation of Java Iterator interface."""
    
    def __init__(self, python_list):
        self.items = python_list
        self.index = 0
    
    def hasNext(self):
        return self.index < len(self.items)
    
    def next(self):
        if not self.hasNext():
            raise jpype.java.util.NoSuchElementException()
        item = self.items[self.index]
        self.index += 1
        return item

# Custom conversion for Python datetime to Java Date
import datetime

@JConversion(jpype.java.util.Date)
class DateTimeConverter:
    """Convert Python datetime to Java Date."""
    
    @staticmethod
    def convert(py_datetime):
        if isinstance(py_datetime, datetime.datetime):
            timestamp_ms = int(py_datetime.timestamp() * 1000)
            return jpype.java.util.Date(timestamp_ms)
        return py_datetime

# Use custom implementations
python_list = ["apple", "banana", "cherry"]
iterator = PythonListIterator(python_list)

# Java code can use our Python iterator
while iterator.hasNext():
    print(f"Next item: {iterator.next()}")

jpype.shutdownJVM()

import jpype
from jpype import dbapi2

jpype.startJVM()

# Add JDBC driver to classpath (example)
# jpype.addClassPath("/path/to/jdbc-driver.jar")

# SQL type mapping using dbapi2 constants
sql_type_names = {
    dbapi2.VARCHAR: "VARCHAR",
    dbapi2.INTEGER: "INTEGER", 
    dbapi2.BIGINT: "BIGINT",
    dbapi2.DECIMAL: "DECIMAL",
    dbapi2.BOOLEAN: "BOOLEAN",
    dbapi2.DATE: "DATE",
    dbapi2.TIMESTAMP: "TIMESTAMP",
    dbapi2.BLOB: "BLOB",
    dbapi2.CLOB: "CLOB"
}

def map_java_sql_type(java_type_code):
    """Map Java SQL type code to readable name."""
    return sql_type_names.get(java_type_code, f"UNKNOWN({java_type_code})")

# Example JDBC operations (requires JDBC driver)
try:
    # Load JDBC driver (example)
    # driver_class = jpype.JClass("com.example.jdbc.Driver")
    # jpype.java.sql.DriverManager.registerDriver(driver_class())
    
    # Example connection (would need real database)
    # connection = jpype.java.sql.DriverManager.getConnection("jdbc:example://localhost")
    # metadata = connection.getMetaData()
    
    print("SQL type constants available:")
    for constant_name in dir(dbapi2):
        if constant_name.isupper() and not constant_name.startswith('_'):
            value = getattr(dbapi2, constant_name)
            if isinstance(value, int):
                print(f"  {constant_name}: {value}")
    
except Exception as e:
    print(f"JDBC example requires database driver: {e}")

jpype.shutdownJVM()

import jpype
import platform

if platform.system() == "Darwin":  # macOS only
    
    def gui_callback():
        """Callback for GUI environment setup."""
        print("GUI environment initialized")
        # Additional GUI setup code here
    
    # Setup GUI before creating Swing components
    jpype.startJVM()
    jpype.setupGuiEnvironment(gui_callback)
    
    # Now safe to create Swing/AWT components
    JFrame = jpype.javax.swing.JFrame
    JButton = jpype.javax.swing.JButton
    
    frame = JFrame("Test Window")
    button = JButton("Click Me")
    frame.add(button)
    frame.setSize(300, 200)
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
    
    # For actual display, uncomment:
    # frame.setVisible(True)
    
    # Cleanup GUI environment
    jpype.shutdownGuiEnvironment()
    jpype.shutdownJVM()
    
else:
    print("GUI environment setup is macOS-specific")

import jpype
import gc
import time

jpype.startJVM()

def performance_test():
    """Test performance optimization techniques."""
    
    # Large object creation test
    start_time = time.time()
    
    # Create many Java objects
    objects = []
    for i in range(10000):
        string_obj = jpype.java.lang.String(f"Object {i}")
        objects.append(string_obj)
    
    creation_time = time.time() - start_time
    print(f"Created 10000 objects in {creation_time:.3f} seconds")
    
    # Memory usage optimization
    # Clear Python references
    objects.clear()
    
    # Force garbage collection
    gc.collect()
    
    # Java garbage collection hint
    jpype.java.lang.System.gc()
    
    # Check memory usage
    runtime = jpype.java.lang.Runtime.getRuntime()
    total_memory = runtime.totalMemory()
    free_memory = runtime.freeMemory()
    used_memory = total_memory - free_memory
    
    print(f"JVM Memory - Total: {total_memory//1024//1024}MB, " +
          f"Used: {used_memory//1024//1024}MB, " +
          f"Free: {free_memory//1024//1024}MB")

performance_test()
jpype.shutdownJVM()

import jpype
from jpype import JImplements, JOverride

jpype.startJVM()

# Custom exception handler
@JImplements("java.lang.Thread$UncaughtExceptionHandler")
class PythonExceptionHandler:
    """Python implementation of Java UncaughtExceptionHandler."""
    
    @JOverride
    def uncaughtException(self, thread, exception):
        print(f"Uncaught exception in thread {thread.getName()}: {exception}")
        # Could log to Python logging system, send alerts, etc.

# Set global exception handler
handler = PythonExceptionHandler()
jpype.java.lang.Thread.setDefaultUncaughtExceptionHandler(handler)

# Create thread that will throw exception
@JImplements("java.lang.Runnable")
class FailingTask:
    @JOverride  
    def run(self):
        raise jpype.java.lang.RuntimeException("This task always fails!")

# Run failing task in Java thread
failing_task = FailingTask()
thread = jpype.java.lang.Thread(failing_task, "FailingThread")
thread.start()
thread.join()

jpype.shutdownJVM()