Java tutorial
/* * Copyright 2002-2019 the original author or authors. * * 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 * * 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 org.springframework.data.gemfire.function; import static org.springframework.data.gemfire.util.CollectionUtils.asSet; import java.lang.reflect.Method; import java.util.Collection; import java.util.Collections; import org.apache.geode.cache.Region; import org.apache.geode.cache.execute.Function; import org.apache.geode.cache.execute.FunctionContext; import org.apache.geode.cache.execute.ResultSender; import org.apache.geode.management.internal.security.ResourcePermissions; import org.apache.geode.security.ResourcePermission; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.ObjectUtils; import org.springframework.util.ReflectionUtils; import org.springframework.util.StringUtils; /** * Invokes a given {@link Object POJO} {@link Method} as a (remote) Pivotal GemFire/Apache Geode {@link Function}. * * If the {@link Object POJO} has a constructor that takes a {@link java.util.Map}, and the {@link Function} context * is a {@link Region}, the {@link Region} will be injected. * * The delegate {@link Class#getName() class name}, the {@link Method#getName() method name}, * and {@link Method} arguments are part of the {@link Function} invocation, therefore all arguments * must be {@link java.io.Serializable} or an alternate serialization strategy must be used. * * The delegate {@link Class} must be on the class path of the remote cache(s). * * @author David Turanski * @author John Blum * @see org.apache.geode.cache.execute.Function * @since 1.2.0 */ @SuppressWarnings("serial") public class PojoFunctionWrapper implements Function { private static transient Logger logger = LoggerFactory.getLogger(PojoFunctionWrapper.class); private volatile boolean HA; private volatile boolean hasResult; private volatile boolean optimizeForWrite; private volatile int batchSize; private Collection<ResourcePermission> requiredPermissions = asSet(ResourcePermissions.DATA_WRITE); private final FunctionArgumentResolver functionArgumentResolver; private final Method method; private final Object target; private final String id; public PojoFunctionWrapper(Object target, Method method) { this(target, method, null); } public PojoFunctionWrapper(Object target, Method method, String id) { this.target = target; this.method = method; this.id = resolveId(method, id); this.functionArgumentResolver = newFunctionArgumentResolver(method); this.HA = false; this.hasResult = resolveHasResult(method); this.optimizeForWrite = false; } protected FunctionArgumentResolver newFunctionArgumentResolver(Method method) { return new FunctionContextInjectingArgumentResolver(method); } protected boolean resolveHasResult(Method method) { return !method.getReturnType().equals(void.class); } protected String resolveId(Method method, String id) { return StringUtils.hasText(id) ? id : method.getName(); } public void setBatchSize(int batchSize) { this.batchSize = batchSize; } public int getBatchSize() { return this.batchSize; } public void setHA(boolean HA) { this.HA = HA; } @Override public boolean isHA() { return this.HA; } public void setHasResult(boolean hasResult) { this.hasResult = hasResult; } @Override public boolean hasResult() { return this.hasResult; } @Override public String getId() { return this.id; } public void setOptimizeForWrite(boolean optimizeForWrite) { this.optimizeForWrite = optimizeForWrite; } @Override public boolean optimizeForWrite() { return this.optimizeForWrite; } public void setRequiredPermissions(Collection<ResourcePermission> requiredPermissions) { this.requiredPermissions = requiredPermissions; } @Override public Collection<ResourcePermission> getRequiredPermissions(String regionName) { return Collections.unmodifiableCollection(this.requiredPermissions); } @Override @SuppressWarnings("unchecked") public void execute(FunctionContext functionContext) { Object[] args = this.functionArgumentResolver.resolveFunctionArguments(functionContext); Object result = invokeTargetMethod(args); if (hasResult()) { sendResults(functionContext.getResultSender(), result); } } protected final Object invokeTargetMethod(Object[] args) { if (logger.isDebugEnabled()) { if (logger.isDebugEnabled()) { logger.debug("About to invoke method [{}] on class [{}] as Function [{}]", this.method.getName(), this.target.getClass().getName(), getId()); } for (Object arg : args) { logger.debug("Argument of type [{}] is [{}]", arg.getClass().getName(), arg.toString()); } } return ReflectionUtils.invokeMethod(this.method, this.target, (Object[]) args); } private void sendResults(ResultSender<Object> resultSender, Object result) { if (result == null) { resultSender.lastResult(null); } else { if (ObjectUtils.isArray(result)) { new BatchingResultSender(this.batchSize, resultSender).sendArrayResults(result); } else if (Iterable.class.isAssignableFrom(result.getClass())) { new BatchingResultSender(this.batchSize, resultSender).sendResults((Iterable<?>) result); } else { resultSender.lastResult(result); } } } }