/* | |
* Copyright 1999-2011 Alibaba Group. | |
* | |
* 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.alibaba.dubbo.remoting.p2p.support; | |
import java.io.File; | |
import java.io.IOException; | |
import java.net.InetSocketAddress; | |
import java.util.ArrayList; | |
import java.util.List; | |
import java.util.concurrent.Executors; | |
import java.util.concurrent.ScheduledExecutorService; | |
import java.util.concurrent.ScheduledFuture; | |
import java.util.concurrent.TimeUnit; | |
import com.alibaba.dubbo.common.URL; | |
import com.alibaba.dubbo.common.utils.IOUtils; | |
import com.alibaba.dubbo.common.utils.NamedThreadFactory; | |
import com.alibaba.dubbo.common.utils.NetUtils; | |
import com.alibaba.dubbo.remoting.ChannelHandler; | |
import com.alibaba.dubbo.remoting.RemotingException; | |
import com.alibaba.dubbo.remoting.p2p.Peer; | |
/** | |
* FileGroup | |
* | |
* @author william.liangf | |
*/ | |
public class FileGroup extends AbstractGroup { | |
private final File file; | |
private volatile long last; | |
// 定时任务执行器 | |
private final ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(3, new NamedThreadFactory("FileGroupModifiedChecker", true)); | |
// 重连定时器,定时检查连接是否可用,不可用时,无限次重连 | |
private final ScheduledFuture<?> checkModifiedFuture; | |
public FileGroup(URL url){ | |
super(url); | |
String path = url.getAbsolutePath(); | |
file = new File(path); | |
checkModifiedFuture = scheduledExecutorService.scheduleWithFixedDelay(new Runnable() { | |
public void run() { | |
// 检测文件变更 | |
try { | |
check(); | |
} catch (Throwable t) { // 防御性容错 | |
logger.error("Unexpected error occur at reconnect, cause: " + t.getMessage(), t); | |
} | |
} | |
}, 2000, 2000, TimeUnit.MILLISECONDS); | |
} | |
public void close() { | |
super.close(); | |
try { | |
if (! checkModifiedFuture.isCancelled()) { | |
checkModifiedFuture.cancel(true); | |
} | |
} catch (Throwable t) { | |
logger.error(t.getMessage(), t); | |
} | |
} | |
private void check() throws RemotingException { | |
long modified = file.lastModified(); | |
if (modified > last) { | |
last = modified; | |
changed(); | |
} | |
} | |
private void changed() throws RemotingException { | |
try { | |
String[] lines = IOUtils.readLines(file); | |
for (String line : lines) { | |
connect(URL.valueOf(line)); | |
} | |
} catch (IOException e) { | |
throw new RemotingException(new InetSocketAddress(NetUtils.getLocalHost(), 0), getUrl().toInetSocketAddress(), e.getMessage(), e); | |
} | |
} | |
public Peer join(URL url, ChannelHandler handler) throws RemotingException { | |
Peer peer = super.join(url, handler); | |
try { | |
String full = url.toFullString(); | |
String[] lines = IOUtils.readLines(file); | |
for (String line : lines) { | |
if (full.equals(line)) { | |
return peer; | |
} | |
} | |
IOUtils.appendLines(file, new String[] {full}); | |
} catch (IOException e) { | |
throw new RemotingException(new InetSocketAddress(NetUtils.getLocalHost(), 0), getUrl().toInetSocketAddress(), e.getMessage(), e); | |
} | |
return peer; | |
} | |
@Override | |
public void leave(URL url) throws RemotingException { | |
super.leave(url); | |
try { | |
String full = url.toFullString(); | |
String[] lines = IOUtils.readLines(file); | |
List<String> saves = new ArrayList<String>(); | |
for (String line : lines) { | |
if (full.equals(line)) { | |
return; | |
} | |
saves.add(line); | |
} | |
IOUtils.appendLines(file, saves.toArray(new String[0])); | |
} catch (IOException e) { | |
throw new RemotingException(new InetSocketAddress(NetUtils.getLocalHost(), 0), getUrl().toInetSocketAddress(), e.getMessage(), e); | |
} | |
} | |
} |