com.base4j.j2cache.JGroupsCacheChannel Maven / Gradle / Ivy
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package com.base4j.j2cache;
import java.net.URL;
import java.util.List;
import org.jgroups.Address;
import org.jgroups.JChannel;
import org.jgroups.Message;
import org.jgroups.ReceiverAdapter;
import org.jgroups.View;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 使用 JGroups 进行组播
* @author winterlau
*/
public class JGroupsCacheChannel extends ReceiverAdapter implements CacheExpiredListener, CacheChannel {
private final static Logger log = LoggerFactory.getLogger(JGroupsCacheChannel.class);
private final static String CONFIG_XML = "/network.xml";
private String name;
private JChannel channel;
private final static JGroupsCacheChannel instance = new JGroupsCacheChannel("default");
/**
* 单例方法
* @return 返回 CacheChannel 单实例
*/
public final static JGroupsCacheChannel getInstance(){
return instance;
}
/**
* 初始化缓存通道并连接
* @param name: 缓存实例名称
*/
private JGroupsCacheChannel(String name) throws CacheException {
this.name = name;
try{
CacheManager.initCacheProvider(this);
long ct = System.currentTimeMillis();
URL xml = CacheChannel.class.getResource(CONFIG_XML);
if(xml == null)
xml = getClass().getClassLoader().getParent().getResource(CONFIG_XML);
channel = new JChannel(xml);
channel.setReceiver(this);
channel.connect(this.name);
log.info("Connected to channel:" + this.name + ", time " + (System.currentTimeMillis()-ct) + " ms.");
}catch(Exception e){
throw new CacheException(e);
}
}
/**
* 获取缓存中的数据
* @param region: Cache Region name
* @param key: Cache key
* @return cache object
*/
public CacheObject get(String region, Object key){
CacheObject obj = new CacheObject();
obj.setRegion(region);
obj.setKey(key);
if(region!=null && key != null){
obj.setValue(CacheManager.get(LEVEL_1, region, key));
if(obj.getValue() == null) {
obj.setValue(CacheManager.get(LEVEL_2, region, key));
if(obj.getValue() != null){
obj.setLevel(LEVEL_2);
CacheManager.set(LEVEL_1, region, key, obj.getValue());
}
}
else
obj.setLevel(LEVEL_1);
}
return obj;
}
/**
* 写入缓存
* @param region: Cache Region name
* @param key: Cache key
* @param value: Cache value
*/
public void set(String region, Object key, Object value){
if(region!=null && key != null){
if(value == null)
evict(region, key);
else{
//分几种情况
//Object obj1 = CacheManager.get(LEVEL_1, region, key);
//Object obj2 = CacheManager.get(LEVEL_2, region, key);
//1. L1 和 L2 都没有
//2. L1 有 L2 没有（这种情况不存在，除非是写 L2 的时候失败
//3. L1 没有，L2 有
//4. L1 和 L2 都有
_sendEvictCmd(region, key);//清除原有的一级缓存的内容
CacheManager.set(LEVEL_1, region, key, value);
CacheManager.set(LEVEL_2, region, key, value);
}
}
//log.info("write data to cache region="+region+",key="+key+",value="+value);
}
public void set(String region, Object key, Object value, Integer expireInSec){
if(region!=null && key != null){
if(value == null)
evict(region, key);
else{
//分几种情况
//Object obj1 = CacheManager.get(LEVEL_1, region, key);
//Object obj2 = CacheManager.get(LEVEL_2, region, key);
//1. L1 和 L2 都没有
//2. L1 有 L2 没有（这种情况不存在，除非是写 L2 的时候失败
//3. L1 没有，L2 有
//4. L1 和 L2 都有
_sendEvictCmd(region, key);//清除原有的一级缓存的内容
CacheManager.set(LEVEL_1, region, key, value, expireInSec);
CacheManager.set(LEVEL_2, region, key, value, expireInSec);
}
}
//log.info("write data to cache region="+region+",key="+key+",value="+value);
}
/**
* 删除缓存
* @param region: Cache Region name
* @param key: Cache key
*/
public void evict(String region, Object key) {
CacheManager.evict(LEVEL_1, region, key); //删除一级缓存
CacheManager.evict(LEVEL_2, region, key); //删除二级缓存
_sendEvictCmd(region, key); //发送广播
}
/**
* 批量删除缓存
* @param region: Cache region name
* @param keys: Cache key
*/
@SuppressWarnings({ "rawtypes" })
public void batchEvict(String region, List keys) {
CacheManager.batchEvict(LEVEL_1, region, keys);
CacheManager.batchEvict(LEVEL_2, region, keys);
_sendEvictCmd(region, keys);
}
/**
* Clear the cache
* @param region: Cache region name
*/
public void clear(String region) throws CacheException {
CacheManager.clear(LEVEL_1, region);
CacheManager.clear(LEVEL_2, region);
_sendClearCmd(region);
}
/**
* Get cache region keys
* @param region: Cache region name
* @return key list
*/
@SuppressWarnings("rawtypes")
public List keys(String region) throws CacheException {
return CacheManager.keys(LEVEL_1, region);
}
/**
* 为了保证每个节点缓存的一致，当某个缓存对象因为超时被清除时，应该通知群组其他成员
* @param region: Cache region name
* @param key: cache key
*/
@Override
@SuppressWarnings("rawtypes")
public void notifyElementExpired(String region, Object key) {
log.debug("Cache data expired, region="+region+",key="+key);
//删除二级缓存
if(key instanceof List)
CacheManager.batchEvict(LEVEL_2, region, (List)key);
else
CacheManager.evict(LEVEL_2, region, key);
//发送广播
_sendEvictCmd(region, key);
}
/**
* 发送删除缓存的广播命令
* @param region: Cache region name
* @param key: cache key
*/
private void _sendEvictCmd(String region, Object key) {
//发送广播
Command cmd = new Command(Command.OPT_DELETE_KEY, region, key);
try {
Message msg = new Message(null, null, cmd.toBuffers());
channel.send(msg);
} catch (Exception e) {
log.error("Unable to delete cache,region="+region+",key="+key, e);
}
}
/**
* 发送清除缓存的广播命令
* @param region: Cache region name
* @param key: cache key
*/
private void _sendClearCmd(String region) {
//发送广播
Command cmd = new Command(Command.OPT_CLEAR_KEY, region, "");
try {
Message msg = new Message(null, null, cmd.toBuffers());
channel.send(msg);
} catch (Exception e) {
log.error("Unable to clear cache,region="+region, e);
}
}
/**
* 删除一级缓存的键对应内容
* @param region: Cache region name
* @param key: cache key
*/
@SuppressWarnings("rawtypes")
protected void onDeleteCacheKey(String region, Object key){
if(key instanceof List)
CacheManager.batchEvict(LEVEL_1, region, (List)key);
else
CacheManager.evict(LEVEL_1, region, key);
log.debug("Received cache evict message, region="+region+",key="+key);
}
/**
* 清除一级缓存的键对应内容
* @param region
* Cache region name
*/
protected void onClearCacheKey(String region){
CacheManager.clear(LEVEL_1, region);
log.debug("Received cache clear message, region="+region);
}
/**
* 消息接收
* @param msg 接收到的消息
*/
@Override
public void receive(Message msg) {
//无效消息
byte[] buffers = msg.getBuffer();
if(buffers.length < 1){
log.warn("Message is empty.");
return;
}
//不处理发送给自己的消息
if(msg.getSrc().equals(channel.getAddress()))
return ;
try{
Command cmd = Command.parse(buffers);
if(cmd == null)
return;
switch(cmd.getOperator()){
case Command.OPT_DELETE_KEY:
onDeleteCacheKey(cmd.getRegion(), cmd.getKey());
break;
case Command.OPT_CLEAR_KEY:
onClearCacheKey(cmd.getRegion());
break;
default:
log.warn("Unknown message type = " + cmd.getOperator());
}
}catch(Exception e){
log.error("Unable to handle received msg" , e);
}
}
/**
* 组中成员变化时
* @param view group view
*/
public void viewAccepted(View view) {
StringBuffer sb = new StringBuffer("Group Members Changed, LIST: ");
List addrs = view.getMembers();
for(int i=0; i 0)
sb.append(',');
sb.append(addrs.get(i).toString());
}
log.info(sb.toString());
}
/**
* 关闭到通道的连接
*/
public void close(){
CacheManager.shutdown(LEVEL_1);
CacheManager.shutdown(LEVEL_2);
channel.close();
}
}