io.netty.channel.group.ChannelMatchers Maven / Gradle / Ivy
/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you 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:
*
* https://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 io.netty.channel.group;
import io.netty.channel.Channel;
import io.netty.channel.ServerChannel;
/**
* Helper class which provides often used {@link ChannelMatcher} implementations.
*/
public final class ChannelMatchers {
private static final ChannelMatcher ALL_MATCHER = new ChannelMatcher() {
@Override
public boolean matches(Channel channel) {
return true;
}
};
private static final ChannelMatcher SERVER_CHANNEL_MATCHER = isInstanceOf(ServerChannel.class);
private static final ChannelMatcher NON_SERVER_CHANNEL_MATCHER = isNotInstanceOf(ServerChannel.class);
private ChannelMatchers() {
// static methods only
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s.
*/
public static ChannelMatcher all() {
return ALL_MATCHER;
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s except the given.
*/
public static ChannelMatcher isNot(Channel channel) {
return invert(is(channel));
}
/**
* Returns a {@link ChannelMatcher} that matches the given {@link Channel}.
*/
public static ChannelMatcher is(Channel channel) {
return new InstanceMatcher(channel);
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s that are an instance of sub-type of
* the given class.
*/
public static ChannelMatcher isInstanceOf(Class clazz) {
return new ClassMatcher(clazz);
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s that are not an
* instance of sub-type of the given class.
*/
public static ChannelMatcher isNotInstanceOf(Class clazz) {
return invert(isInstanceOf(clazz));
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s that are of type {@link ServerChannel}.
*/
public static ChannelMatcher isServerChannel() {
return SERVER_CHANNEL_MATCHER;
}
/**
* Returns a {@link ChannelMatcher} that matches all {@link Channel}s that are not of type
* {@link ServerChannel}.
*/
public static ChannelMatcher isNonServerChannel() {
return NON_SERVER_CHANNEL_MATCHER;
}
/**
* Invert the given {@link ChannelMatcher}.
*/
public static ChannelMatcher invert(ChannelMatcher matcher) {
return new InvertMatcher(matcher);
}
/**
* Return a composite of the given {@link ChannelMatcher}s. This means all {@link ChannelMatcher} must
* return {@code true} to match.
*/
public static ChannelMatcher compose(ChannelMatcher... matchers) {
if (matchers.length < 1) {
throw new IllegalArgumentException("matchers must at least contain one element");
}
if (matchers.length == 1) {
return matchers[0];
}
return new CompositeMatcher(matchers);
}
private static final class CompositeMatcher implements ChannelMatcher {
private final ChannelMatcher[] matchers;
CompositeMatcher(ChannelMatcher... matchers) {
this.matchers = matchers;
}
@Override
public boolean matches(Channel channel) {
for (ChannelMatcher m: matchers) {
if (!m.matches(channel)) {
return false;
}
}
return true;
}
}
private static final class InvertMatcher implements ChannelMatcher {
private final ChannelMatcher matcher;
InvertMatcher(ChannelMatcher matcher) {
this.matcher = matcher;
}
@Override
public boolean matches(Channel channel) {
return !matcher.matches(channel);
}
}
private static final class InstanceMatcher implements ChannelMatcher {
private final Channel channel;
InstanceMatcher(Channel channel) {
this.channel = channel;
}
@Override
public boolean matches(Channel ch) {
return channel == ch;
}
}
private static final class ClassMatcher implements ChannelMatcher {
private final Class clazz;
ClassMatcher(Class clazz) {
this.clazz = clazz;
}
@Override
public boolean matches(Channel ch) {
return clazz.isInstance(ch);
}
}
}