Java tutorial
package code.google.nfs.rpc.client; /** * nfs-rpc * Apache License * * http://code.google.com/p/nfs-rpc (c) 2011 */ import java.util.List; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.TimeUnit; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import code.google.nfs.rpc.Codecs; import code.google.nfs.rpc.RequestWrapper; import code.google.nfs.rpc.ResponseWrapper; /** * Common Client,support sync invoke * * @author <a href="mailto:bluedavy@gmail.com">bluedavy</a> */ public abstract class AbstractClient implements Client { private static final Log LOGGER = LogFactory.getLog(AbstractClient.class); private static final boolean isDebugEnabled = LOGGER.isDebugEnabled(); private static final boolean isWarnEnabled = LOGGER.isWarnEnabled(); private static final long PRINT_CONSUME_MINTIME = Long .parseLong(System.getProperty("nfs.rpc.print.consumetime", "0")); protected static ConcurrentHashMap<Integer, ArrayBlockingQueue<Object>> responses = new ConcurrentHashMap<Integer, ArrayBlockingQueue<Object>>(); public Object invokeSync(Object message, int timeout, int codecType, int protocolType) throws Exception { RequestWrapper wrapper = new RequestWrapper(message, timeout, codecType, protocolType); return invokeSyncIntern(wrapper); } public Object invokeSync(String targetInstanceName, String methodName, String[] argTypes, Object[] args, int timeout, int codecType, int protocolType) throws Exception { byte[][] argTypeBytes = new byte[argTypes.length][]; for (int i = 0; i < argTypes.length; i++) { argTypeBytes[i] = argTypes[i].getBytes(); } RequestWrapper wrapper = new RequestWrapper(targetInstanceName.getBytes(), methodName.getBytes(), argTypeBytes, args, timeout, codecType, protocolType); return invokeSyncIntern(wrapper); } private Object invokeSyncIntern(RequestWrapper wrapper) throws Exception { long beginTime = System.currentTimeMillis(); ArrayBlockingQueue<Object> responseQueue = new ArrayBlockingQueue<Object>(1); responses.put(wrapper.getId(), responseQueue); ResponseWrapper responseWrapper = null; try { if (isDebugEnabled) { // for performance trace LOGGER.debug("client ready to send message,request id: " + wrapper.getId()); } getClientFactory().checkSendLimit(); sendRequest(wrapper, wrapper.getTimeout()); if (isDebugEnabled) { // for performance trace LOGGER.debug( "client write message to send buffer,wait for response,request id: " + wrapper.getId()); } } catch (Exception e) { responses.remove(wrapper.getId()); responseQueue = null; LOGGER.error("send request to os sendbuffer error", e); throw e; } Object result = null; try { result = responseQueue.poll(wrapper.getTimeout() - (System.currentTimeMillis() - beginTime), TimeUnit.MILLISECONDS); } catch (Exception e) { responses.remove(wrapper.getId()); LOGGER.error("Get response error", e); throw new Exception("Get response error", e); } responses.remove(wrapper.getId()); if (PRINT_CONSUME_MINTIME > 0 && isWarnEnabled) { long consumeTime = System.currentTimeMillis() - beginTime; if (consumeTime > PRINT_CONSUME_MINTIME) { LOGGER.warn("client.invokeSync consume time: " + consumeTime + " ms, server is: " + getServerIP() + ":" + getServerPort() + " request id is:" + wrapper.getId()); } } if (result == null) { String errorMsg = "receive response timeout(" + wrapper.getTimeout() + " ms),server is: " + getServerIP() + ":" + getServerPort() + " request id is:" + wrapper.getId(); throw new Exception(errorMsg); } if (result instanceof ResponseWrapper) { responseWrapper = (ResponseWrapper) result; } else if (result instanceof List) { @SuppressWarnings("unchecked") List<ResponseWrapper> responseWrappers = (List<ResponseWrapper>) result; for (ResponseWrapper response : responseWrappers) { if (response.getRequestId() == wrapper.getId()) { responseWrapper = response; } else { putResponse(response); } } } else { throw new Exception("only receive ResponseWrapper or List as response"); } try { // do deserialize in business threadpool if (responseWrapper.getResponse() instanceof byte[]) { String responseClassName = null; if (responseWrapper.getResponseClassName() != null) { responseClassName = new String(responseWrapper.getResponseClassName()); } // avoid server no return object if (((byte[]) responseWrapper.getResponse()).length == 0) { responseWrapper.setResponse(null); } else { Object responseObject = Codecs.getDecoder(responseWrapper.getCodecType()) .decode(responseClassName, (byte[]) responseWrapper.getResponse()); if (responseObject instanceof Throwable) { responseWrapper.setException((Throwable) responseObject); } else { responseWrapper.setResponse(responseObject); } } } } catch (Exception e) { LOGGER.error("Deserialize response object error", e); throw new Exception("Deserialize response object error", e); } if (responseWrapper.isError()) { Throwable t = responseWrapper.getException(); t.fillInStackTrace(); String errorMsg = "server error,server is: " + getServerIP() + ":" + getServerPort() + " request id is:" + wrapper.getId(); LOGGER.error(errorMsg, t); throw new Exception(errorMsg, t); } return responseWrapper.getResponse(); } /** * receive response */ public void putResponse(ResponseWrapper wrapper) throws Exception { if (!responses.containsKey(wrapper.getRequestId())) { LOGGER.warn("give up the response,request id is:" + wrapper.getRequestId() + ",maybe because timeout!"); return; } try { ArrayBlockingQueue<Object> queue = responses.get(wrapper.getRequestId()); if (queue != null) { queue.put(wrapper); } else { LOGGER.warn( "give up the response,request id is:" + wrapper.getRequestId() + ",because queue is null"); } } catch (InterruptedException e) { LOGGER.error("put response error,request id is:" + wrapper.getRequestId(), e); } } /** * receive responses */ public void putResponses(List<ResponseWrapper> wrappers) throws Exception { for (ResponseWrapper wrapper : wrappers) { if (!responses.containsKey(wrapper.getRequestId())) { LOGGER.warn( "give up the response,request id is:" + wrapper.getRequestId() + ",maybe because timeout!"); continue; } try { ArrayBlockingQueue<Object> queue = responses.get(wrapper.getRequestId()); if (queue != null) { queue.put(wrappers); break; } else { LOGGER.warn("give up the response,request id is:" + wrapper.getRequestId() + ",because queue is null"); } } catch (InterruptedException e) { LOGGER.error("put response error,request id is:" + wrapper.getRequestId(), e); } } } /** * send request to os sendbuffer,must ensure write result */ public abstract void sendRequest(RequestWrapper wrapper, int timeout) throws Exception; }