Java tutorial
/* * Copyright (c) 2012 S.C. Axemblr Software Solutions S.R.L * * 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.axemblr.provisionr.amazon.activities; import com.amazonaws.AmazonServiceException; import com.amazonaws.services.ec2.AmazonEC2; import com.amazonaws.services.ec2.model.DescribeInstancesRequest; import com.amazonaws.services.ec2.model.DescribeInstancesResult; import com.amazonaws.services.ec2.model.Instance; import com.axemblr.provisionr.amazon.ProcessVariables; import com.axemblr.provisionr.amazon.core.ProviderClientCache; import com.axemblr.provisionr.api.pool.Pool; import static com.google.common.base.Preconditions.checkNotNull; import static com.google.common.base.Preconditions.checkState; import com.google.common.base.Predicate; import com.google.common.base.Throwables; import com.google.common.collect.Iterables; import java.util.List; import org.activiti.engine.delegate.DelegateExecution; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public abstract class AllInstancesMatchPredicate extends AmazonActivity { private static final Logger LOG = LoggerFactory.getLogger(AllInstancesMatchPredicate.class); private final String resultVariable; private final Predicate<Instance> predicate; protected AllInstancesMatchPredicate(ProviderClientCache cache, String resultVariable, Predicate<Instance> predicate) { super(cache); this.resultVariable = checkNotNull(resultVariable, "resultVariable is null"); this.predicate = checkNotNull(predicate, "predicate is null"); } @Override public void execute(AmazonEC2 client, Pool pool, DelegateExecution execution) throws Exception { @SuppressWarnings("unchecked") List<String> instanceIds = (List<String>) execution.getVariable(ProcessVariables.INSTANCE_IDS); checkNotNull(instanceIds, "process variable '{}' not found", ProcessVariables.INSTANCE_IDS); try { DescribeInstancesResult result = client .describeInstances(new DescribeInstancesRequest().withInstanceIds(instanceIds)); checkState(result.getReservations().size() == 1, "the instance ids are part of multiple reservations"); List<Instance> instances = result.getReservations().get(0).getInstances(); if (Iterables.all(instances, predicate)) { LOG.info(">> All {} instances match predicate {} ", instanceIds, predicate); execution.setVariable(resultVariable, true); } else { LOG.info("<< Not all instances {} match predicate {}", instanceIds, predicate); execution.setVariable(resultVariable, false); } } catch (AmazonServiceException exception) { if (exception.getErrorCode().equalsIgnoreCase("InvalidInstanceID.NotFound")) { LOG.warn("<< Got error InvalidInstanceID.NotFound. Assuming predicate {} is false", predicate); execution.setVariable(resultVariable, false); } else { throw Throwables.propagate(exception); } } } }