com.wavemaker.commons.properties.ThreadLocalSystemProperties Maven / Gradle / Ivy
/**
* Copyright (C) 2020 WaveMaker, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.wavemaker.commons.properties;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.stream.Collectors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Support for storing System.setProperty calls in thread local.
* Mainly used to deal with third party libraries which sets new system properties and never clear them.
*
* To Enable usage of this class a single call to {@link #enable()} has to be done.
* To Disable usage of this class, a call to {@link #disable()} need to be made. This needs to be done to remove all
* references for this class's classloader for
* smooth class unloading.
*
* Calling {@link #record()} before any such operation will store all calls to {@link System#setProperty(String,
* String)} in the current thread local only.
* Even for properties which are already defined in global level a new property is created in thread local
* Also calls to {@link System#getProperty(String)} will return values from current thread local and falls back to
* global vm level properties if not present
* in thread local.
*
* Calling {@link #stop()} will stop storing in thread local and any call to {@link System#setProperty(String, String)}
* will be store in global vm level
* properties for the current thread.
*
* @author Uday Shankar
*/
public class ThreadLocalSystemProperties extends Properties {
private static final ThreadLocal THREAD_LOCAL_PROPERTIES = new ThreadLocal<>();
private static final Properties VM_LEVEL_PROPERTIES = System.getProperties();
private static final ThreadLocalSystemProperties INSTANCE = new ThreadLocalSystemProperties();
private static final Logger logger = LoggerFactory.getLogger(ThreadLocalSystemProperties.class);
private ThreadLocalSystemProperties() {
super(VM_LEVEL_PROPERTIES);
}
/**
* Will set ThreadLocalProperties as the default System properties at the vm level
* Existing System properties are still available by default at global level across all threads
*/
public synchronized ThreadLocalSystemProperties enable() {
Properties currentSystemProperties = System.getProperties();
if (currentSystemProperties instanceof ThreadLocalSystemProperties) {
logger.info("ThreadLocal based Properties is already set for System Properties");
} else {
logger.info("Setting ThreadLocal based Properties for System.setProperties");
System.setProperties(ThreadLocalSystemProperties.INSTANCE);
logger.info("Set ThreadLocal based Properties for System.setProperties!!");
}
return INSTANCE;
}
/**
* Will only disable ThreadLocalProperties at the vm level
* Vm level properties previously set will still be present
*/
public synchronized void disable() {
Properties currentSystemProperties = System.getProperties();
if (currentSystemProperties instanceof ThreadLocalSystemProperties) {
logger.info("Removing ThreadLocal based Properties for System.setProperties");
System.setProperties(VM_LEVEL_PROPERTIES);
logger.info("Removed ThreadLocal based Properties for System.setProperties");
} else {
logger.warn("ThreadLocal based Properties is not enabled for System.setProperties");
}
}
public static synchronized void executeInThreadLocalSystemProperties(Runnable runnable) {
try {
INSTANCE.record();
runnable.run();
} finally {
INSTANCE.stop();
}
}
/**
* Will store properties in thread local on calling System.setProperty post this method call in the current thread
*/
private synchronized void record() {
Properties currentSystemProperties = System.getProperties();
if (currentSystemProperties instanceof ThreadLocalSystemProperties) {
Properties threadLocalProperties = getLocalProperties();
if (threadLocalProperties instanceof ThreadLocalSystemProperties) {
logger.info("Usage of Thread Local properties for current thread is already enabled");
} else {
logger.info("Enabling usage of Thread Local properties for current thread");
THREAD_LOCAL_PROPERTIES.set(new Properties(VM_LEVEL_PROPERTIES));
logger.info("Enabled usage of Thread Local properties for current thread");
}
} else {
throw new IllegalStateException(
"Request for recording ThreadLocal for current thread without enabling the ThreadLocalSystemProperties");
}
}
/**
* Will use global vm level properties to store properties in the current thread
*/
private synchronized void stop() {
Properties currentSystemProperties = System.getProperties();
if (currentSystemProperties instanceof ThreadLocalSystemProperties) {
logger.info("Disabling usage of Thread Local properties for current thread");
THREAD_LOCAL_PROPERTIES.remove();
logger.info("Disabled usage of Thread Local properties for current thread");
} else {
throw new IllegalStateException(
"Request for stopping ThreadLocal for current thread without enabling the ThreadLocalSystemProperties");
}
}
@Override
public String getProperty(String key) {
return getLocalProperties().getProperty(key);
}
@Override
public String getProperty(String key, String defaultValue) {
return getLocalProperties().getProperty(key, defaultValue);
}
@Override
public Object setProperty(String key, String value) {
return getLocalProperties().setProperty(key, value);
}
@Override
public Enumeration propertyNames() {
return getLocalProperties().propertyNames();
}
@Override
public Set stringPropertyNames() {
return getLocalProperties().stringPropertyNames();
}
@Override
public void list(PrintStream out) {
getLocalProperties().list(out);
}
@Override
public void list(PrintWriter out) {
getLocalProperties().list(out);
}
@Override
public Set