高可用的池化thriftclient实现（源码分享）

<dependency>
    <groupId>com.github.cyfonly</groupId>
    <artifactId>thriftj</artifactId>
    <version>1.0.1</version>
</dependency>

//Thrift server 列表
private static final String servers = "127.0.0.1:10001,127.0.0.1:10002";

//TTransport 验证器
ConnectionValidator validator = new ConnectionValidator() {
    @Override
    public boolean isValid(TTransport object) {
        return object.isOpen();
    }
};

//连接对象池配置
GenericKeyedObjectPoolConfig poolConfig = new GenericKeyedObjectPoolConfig();

//failover 策略
FailoverStrategy failoverStrategy = new FailoverStrategy();

//构造 ThriftClient 对象并配置
final ThriftClient thriftClient = new ThriftClient();
thriftClient.servers(servers)
            .loadBalance(Constant.LoadBalance.RANDOM)
            .connectionValidator(validator)
            .poolConfig(poolConfig)
            .failoverStrategy(failoverStrategy)
            .connTimeout(5)
            .backupServers("")
            .serviceLevel(Constant.ServiceLevel.NOT_EMPTY)
            .start();

//打印从 ThriftClient 获取到的可用服务列表
List<ThriftServer> servers = thriftClient.getAvailableServers();
for(ThriftServer server : servers){
    System.out.println(server.getHost() + ":" + server.getPort());
}

//服务调用
if(servers.size()>0){
    try{
            TestThriftJ.Client client = thriftClient.iface(TestThriftJ.Client.class);
            QryResult result = client.qryTest(1);
            System.out.println("result[code=" + result.code + " msg=" + result.msg + "]");
      }catch(Throwable t){
            logger.error("-------------exception happen", t);
      }
}

@Override
public PooledObject<TTransport> makeObject(ThriftServer thriftServer) throws Exception {
    TSocket tsocket = new TSocket(thriftServer.getHost(), thriftServer.getPort());
    tsocket.setTimeout(timeout);
    TFramedTransport transport = new TFramedTransport(tsocket);
    
    transport.open();
    DefaultPooledObject<TTransport> result = new DefaultPooledObject<TTransport>(transport);
    logger.trace("Make new thrift connection: {}:{}", thriftServer.getHost(), thriftServer.getPort());
    
    return result;
}

@Override
public boolean validateObject(ThriftServer thriftServer, PooledObject<TTransport> pooledObject) {
    boolean isValidate;
    try {
        if (failoverChecker == null) {
            isValidate = pooledObject.getObject().isOpen();
        } else {
            ConnectionValidator validator = failoverChecker.getConnectionValidator();
            isValidate = pooledObject.getObject().isOpen() && (validator == null || validator.isValid(pooledObject.getObject()));
        }
    } catch (Throwable e) {
        logger.warn("Fail to validate tsocket: {}:{}", new Object[]{thriftServer.getHost(), thriftServer.getPort(), e});
        isValidate = false;
    }
    if (failoverChecker != null && !isValidate) {
        failoverChecker.getFailoverStrategy().fail(thriftServer);
    }
    logger.info("ValidateObject isValidate:{}", isValidate);
    
    return isValidate;
}

@Override
public void destroyObject(ThriftServer thriftServer, PooledObject<TTransport> pooledObject) throws Exception {
    TTransport transport = pooledObject.getObject();
    if (transport != null) {
        transport.close();
        logger.trace("Close thrift connection: {}:{}", thriftServer.getHost(), thriftServer.getPort());
    }
}

public DefaultThriftConnectionPool(KeyedPooledObjectFactory<ThriftServer, TTransport> factory, GenericKeyedObjectPoolConfig config) {
	connections = new GenericKeyedObjectPool<>(factory, config);
}

@Override
public TTransport getConnection(ThriftServer thriftServer) {
	try {
		return connections.borrowObject(thriftServer);
	} catch (Exception e) {
		logger.warn("Fail to get connection for {}:{}", new Object[]{thriftServer.getHost(), thriftServer.getPort(), e});
		throw new RuntimeException(e);
	}
}

@Override
public void returnConnection(ThriftServer thriftServer, TTransport transport) {
	connections.returnObject(thriftServer, transport);
}

@Override
public void returnBrokenConnection(ThriftServer thriftServer, TTransport transport) {
	try {
		connections.invalidateObject(thriftServer, transport);
	} catch (Exception e) {
		logger.warn("Fail to invalid object:{},{}", new Object[] { thriftServer, transport, e });
	}
}

@Override
public void close() {
	connections.close();
}

@Override
public void clear(ThriftServer thriftServer) {
	connections.clear(thriftServer);
}

if (this.validator == null) {
　　this.validator = new ConnectionValidator() {
　　　　@Override
　　　　public boolean isValid(TTransport object) {
　　　　　　return object.isOpen();
　　　　}
　　};
}

/**
 * 使用默认 failover 策略
 */
public FailoverStrategy() {
	this(DEFAULT_FAIL_COUNT, DEFAULT_FAIL_DURATION, DEFAULT_RECOVER_DURATION);
}

/**
 * 自定义 failover 策略
 * @param failCount 失败次数
 * @param failDuration 失效持续时间
 * @param recoverDuration 恢复持续时间
 */
public FailoverStrategy(final int failCount, long failDuration, long recoverDuration) {
	this.failDuration = failDuration;
	this.failedList = CacheBuilder.newBuilder().weakKeys().expireAfterWrite(recoverDuration, TimeUnit.MILLISECONDS).build();
	this.failCountMap = CacheBuilder.newBuilder().weakKeys().build(new CacheLoader<T, EvictingQueue<Long>>() {
		@Override
		public EvictingQueue<Long> load(T key) throws Exception {
			return EvictingQueue.create(failCount);
		}
	});
}

public void fail(T object) {
	logger.info("Server {}:{} failed.", ((ThriftServer)object).getHost(),((ThriftServer)object).getPort());
	boolean addToFail = false;
	try {
		EvictingQueue<Long> evictingQueue = failCountMap.get(object);
		synchronized (evictingQueue) {
			evictingQueue.add(System.currentTimeMillis());
			if (evictingQueue.remainingCapacity() == 0 && evictingQueue.element() >= (System.currentTimeMillis() - failDuration)) {
				addToFail = true;
			}
		}
	} catch (ExecutionException e) {
		logger.error("Ops.", e);
	}
	if (addToFail) {
		failedList.put(object, Boolean.TRUE);
		logger.info("Server {}:{} failed. Add to fail list.", ((ThriftServer)object).getHost(), ((ThriftServer)object).getPort());
	}
}

public Set<T> getFailed() {
	return failedList.asMap().keySet();
}

private List<ThriftServer> getAvailableServers(boolean all) {
	List<ThriftServer> returnList = new ArrayList<>();
	Set<ThriftServer> failedServers = failoverStrategy.getFailed();
	for (ThriftServer thriftServer : serverList) {
		if (!failedServers.contains(thriftServer))
			returnList.add(thriftServer);
	}
	if (this.serviceLevel == Constant.ServiceLevel.SERVERS_ONLY) {
		return returnList;
	}
	if ((all || returnList.isEmpty()) && !backupServerList.isEmpty()) {
		for (ThriftServer thriftServer : backupServerList) {
			if (!failedServers.contains(thriftServer))
				returnList.add(thriftServer);
		}
	}
	if (this.serviceLevel == Constant.ServiceLevel.ALL_SERVERS) {
		return returnList;
	}
	if(returnList.isEmpty()){
		returnList.addAll(serverList);
	}
	return returnList;
}