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Java 1.8+ Library with tons of utility classes required in all projects
/*
* Copyright (C) 2014-2022 Philip Helger (www.helger.com)
* philip[at]helger[dot]com
*
* 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.helger.commons.url;
import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.GuardedBy;
import javax.annotation.concurrent.ThreadSafe;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.helger.commons.ValueEnforcer;
import com.helger.commons.annotation.ReturnsMutableCopy;
import com.helger.commons.annotation.Singleton;
import com.helger.commons.collection.impl.CommonsHashMap;
import com.helger.commons.collection.impl.ICommonsCollection;
import com.helger.commons.collection.impl.ICommonsMap;
import com.helger.commons.collection.impl.ICommonsSet;
import com.helger.commons.concurrent.SimpleReadWriteLock;
import com.helger.commons.lang.ServiceLoaderHelper;
/**
* A central registry for supported URL protocols. By default, the registry will
* include all protocols contained in {@link EURLProtocol}, but it may be
* extended by custom protocols
*
* @author Boris Gregorcic
* @author Philip Helger
*/
@ThreadSafe
@Singleton
public final class URLProtocolRegistry
{
private static final class SingletonHolder
{
private static final URLProtocolRegistry INSTANCE = new URLProtocolRegistry ();
}
private static final Logger LOGGER = LoggerFactory.getLogger (URLProtocolRegistry.class);
private static boolean s_bDefaultInstantiated = false;
private final SimpleReadWriteLock m_aRWLock = new SimpleReadWriteLock ();
@GuardedBy ("m_aRWLock")
private final ICommonsMap m_aProtocols = new CommonsHashMap <> ();
private URLProtocolRegistry ()
{
reinitialize ();
}
public static boolean isInstantiated ()
{
return s_bDefaultInstantiated;
}
@Nonnull
public static URLProtocolRegistry getInstance ()
{
final URLProtocolRegistry ret = SingletonHolder.INSTANCE;
s_bDefaultInstantiated = true;
return ret;
}
/**
* Registers a new protocol
*
* @param aProtocol
* The protocol to be registered. May not be null.
* @throws IllegalArgumentException
* If another handler for this protocol is already installed.
*/
public void registerProtocol (@Nonnull final IURLProtocol aProtocol)
{
ValueEnforcer.notNull (aProtocol, "Protocol");
final String sProtocol = aProtocol.getProtocol ();
m_aRWLock.writeLocked ( () -> {
if (m_aProtocols.containsKey (sProtocol))
throw new IllegalArgumentException ("Another handler for protocol '" + sProtocol + "' is already registered!");
m_aProtocols.put (sProtocol, aProtocol);
});
if (LOGGER.isDebugEnabled ())
LOGGER.debug ("Registered new custom URL protocol: " + aProtocol);
}
/**
* @return All registered protocols
*/
@Nonnull
@ReturnsMutableCopy
public ICommonsCollection getAllProtocols ()
{
return m_aRWLock.readLockedGet (m_aProtocols::copyOfValues);
}
@Nonnegative
public int getRegisteredProtocolCount ()
{
return m_aRWLock.readLockedInt (m_aProtocols::size);
}
/**
* Try to evaluate the matching URL protocol from the passed URL
*
* @param sURL
* The URL to get the protocol from
* @return The corresponding URL protocol or null if unresolved
*/
@Nullable
public IURLProtocol getProtocol (@Nullable final String sURL)
{
if (sURL == null)
return null;
// Is called often - so no Lambdas
m_aRWLock.readLock ().lock ();
try
{
for (final IURLProtocol aProtocol : m_aProtocols.values ())
if (aProtocol.isUsedInURL (sURL))
return aProtocol;
return null;
}
finally
{
m_aRWLock.readLock ().unlock ();
}
}
/**
* Try to evaluate the matching URL protocol from the passed URL
*
* @param aURL
* The URL data
* @return The corresponding URL protocol or null if unresolved
*/
@Nullable
public IURLProtocol getProtocol (@Nullable final ISimpleURL aURL)
{
return aURL == null ? null : getProtocol (aURL.getPath ());
}
/**
* Check if the passed URL has any known protocol
*
* @param sURL
* The URL to analyze
* @return true if the protocol is known, false
* otherwise
*/
public boolean hasKnownProtocol (@Nullable final String sURL)
{
return getProtocol (sURL) != null;
}
/**
* Check if the passed URL has any known protocol
*
* @param aURL
* The URL to analyze
* @return true if the protocol is known, false
* otherwise
*/
public boolean hasKnownProtocol (@Nullable final ISimpleURL aURL)
{
return getProtocol (aURL) != null;
}
/**
* Return the passed URL where the protocol has been stripped (if known)
*
* @param sURL
* The URL to strip the protocol from. May be null.
* @return The passed URL where any known protocol has been stripped
*/
@Nullable
public String getWithoutProtocol (@Nullable final String sURL)
{
final IURLProtocol aProtocol = getProtocol (sURL);
return aProtocol == null ? sURL : sURL.substring (aProtocol.getProtocol ().length ());
}
/**
* Reinitialize all protocols. Adds all {@link EURLProtocol} values and
* invokes all SPI implementations.
*/
public void reinitialize ()
{
m_aRWLock.writeLocked ( () -> {
m_aProtocols.clear ();
// Add all default protocols
for (final EURLProtocol aProtocol : EURLProtocol.values ())
m_aProtocols.put (aProtocol.getProtocol (), aProtocol);
});
// Load all SPI implementations
for (final IURLProtocolRegistrarSPI aRegistrar : ServiceLoaderHelper.getAllSPIImplementations (IURLProtocolRegistrarSPI.class))
{
final ICommonsSet aURLProtocols = aRegistrar.getAllProtocols ();
if (aURLProtocols != null)
for (final IURLProtocol aSPIProtocol : aURLProtocols)
registerProtocol (aSPIProtocol);
}
if (LOGGER.isDebugEnabled ())
LOGGER.debug (getRegisteredProtocolCount () + " URL protocols registered");
}
}