| 1 | /* |
| 2 | * Copyright 2006-2013 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.springframework.batch.core.step.tasklet; |
| 18 | |
| 19 | import java.io.File; |
| 20 | import java.util.concurrent.Callable; |
| 21 | import java.util.concurrent.FutureTask; |
| 22 | |
| 23 | import org.apache.commons.logging.Log; |
| 24 | import org.apache.commons.logging.LogFactory; |
| 25 | import org.springframework.batch.core.ExitStatus; |
| 26 | import org.springframework.batch.core.JobInterruptedException; |
| 27 | import org.springframework.batch.core.StepContribution; |
| 28 | import org.springframework.batch.core.StepExecution; |
| 29 | import org.springframework.batch.core.listener.StepExecutionListenerSupport; |
| 30 | import org.springframework.batch.core.scope.context.ChunkContext; |
| 31 | import org.springframework.batch.repeat.RepeatStatus; |
| 32 | import org.springframework.beans.factory.InitializingBean; |
| 33 | import org.springframework.core.task.SimpleAsyncTaskExecutor; |
| 34 | import org.springframework.core.task.TaskExecutor; |
| 35 | import org.springframework.util.Assert; |
| 36 | |
| 37 | /** |
| 38 | * {@link Tasklet} that executes a system command. |
| 39 | * |
| 40 | * The system command is executed asynchronously using injected |
| 41 | * {@link #setTaskExecutor(TaskExecutor)} - timeout value is required to be set, |
| 42 | * so that the batch job does not hang forever if the external process hangs. |
| 43 | * |
| 44 | * Tasklet periodically checks for termination status (i.e. |
| 45 | * {@link #setCommand(String)} finished its execution or |
| 46 | * {@link #setTimeout(long)} expired or job was interrupted). The check interval |
| 47 | * is given by {@link #setTerminationCheckInterval(long)}. |
| 48 | * |
| 49 | * When job interrupt is detected tasklet's execution is terminated immediately |
| 50 | * by throwing {@link JobInterruptedException}. |
| 51 | * |
| 52 | * {@link #setInterruptOnCancel(boolean)} specifies whether the tasklet should |
| 53 | * attempt to interrupt the thread that executes the system command if it is |
| 54 | * still running when tasklet exits (abnormally). |
| 55 | * |
| 56 | * @author Robert Kasanicky |
| 57 | */ |
| 58 | public class SystemCommandTasklet extends StepExecutionListenerSupport implements Tasklet, InitializingBean { |
| 59 | |
| 60 | protected static final Log logger = LogFactory.getLog(SystemCommandTasklet.class); |
| 61 | |
| 62 | private String command; |
| 63 | |
| 64 | private String[] environmentParams = null; |
| 65 | |
| 66 | private File workingDirectory = null; |
| 67 | |
| 68 | private SystemProcessExitCodeMapper systemProcessExitCodeMapper = new SimpleSystemProcessExitCodeMapper(); |
| 69 | |
| 70 | private long timeout = 0; |
| 71 | |
| 72 | private long checkInterval = 1000; |
| 73 | |
| 74 | private StepExecution execution = null; |
| 75 | |
| 76 | private TaskExecutor taskExecutor = new SimpleAsyncTaskExecutor(); |
| 77 | |
| 78 | private boolean interruptOnCancel = false; |
| 79 | |
| 80 | /** |
| 81 | * Execute system command and map its exit code to {@link ExitStatus} using |
| 82 | * {@link SystemProcessExitCodeMapper}. |
| 83 | */ |
| 84 | @Override |
| 85 | public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception { |
| 86 | |
| 87 | FutureTask<Integer> systemCommandTask = new FutureTask<Integer>(new Callable<Integer>() { |
| 88 | |
| 89 | @Override |
| 90 | public Integer call() throws Exception { |
| 91 | Process process = Runtime.getRuntime().exec(command, environmentParams, workingDirectory); |
| 92 | return process.waitFor(); |
| 93 | } |
| 94 | |
| 95 | }); |
| 96 | |
| 97 | long t0 = System.currentTimeMillis(); |
| 98 | |
| 99 | taskExecutor.execute(systemCommandTask); |
| 100 | |
| 101 | while (true) { |
| 102 | Thread.sleep(checkInterval); |
| 103 | if (systemCommandTask.isDone()) { |
| 104 | contribution.setExitStatus(systemProcessExitCodeMapper.getExitStatus(systemCommandTask.get())); |
| 105 | return RepeatStatus.FINISHED; |
| 106 | } |
| 107 | else if (System.currentTimeMillis() - t0 > timeout) { |
| 108 | systemCommandTask.cancel(interruptOnCancel); |
| 109 | throw new SystemCommandException("Execution of system command did not finish within the timeout"); |
| 110 | } |
| 111 | else if (execution.isTerminateOnly()) { |
| 112 | systemCommandTask.cancel(interruptOnCancel); |
| 113 | throw new JobInterruptedException("Job interrupted while executing system command '" + command + "'"); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * @param command command to be executed in a separate system process |
| 121 | */ |
| 122 | public void setCommand(String command) { |
| 123 | this.command = command; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * @param envp environment parameter values, inherited from parent process |
| 128 | * when not set (or set to null). |
| 129 | */ |
| 130 | public void setEnvironmentParams(String[] envp) { |
| 131 | this.environmentParams = envp; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * @param dir working directory of the spawned process, inherited from |
| 136 | * parent process when not set (or set to null). |
| 137 | */ |
| 138 | public void setWorkingDirectory(String dir) { |
| 139 | if (dir == null) { |
| 140 | this.workingDirectory = null; |
| 141 | return; |
| 142 | } |
| 143 | this.workingDirectory = new File(dir); |
| 144 | Assert.isTrue(workingDirectory.exists(), "working directory must exist"); |
| 145 | Assert.isTrue(workingDirectory.isDirectory(), "working directory value must be a directory"); |
| 146 | |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | public void afterPropertiesSet() throws Exception { |
| 151 | Assert.hasLength(command, "'command' property value is required"); |
| 152 | Assert.notNull(systemProcessExitCodeMapper, "SystemProcessExitCodeMapper must be set"); |
| 153 | Assert.isTrue(timeout > 0, "timeout value must be greater than zero"); |
| 154 | Assert.notNull(taskExecutor, "taskExecutor is required"); |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * @param systemProcessExitCodeMapper maps system process return value to |
| 159 | * <code>ExitStatus</code> returned by Tasklet. |
| 160 | * {@link SimpleSystemProcessExitCodeMapper} is used by default. |
| 161 | */ |
| 162 | public void setSystemProcessExitCodeMapper(SystemProcessExitCodeMapper systemProcessExitCodeMapper) { |
| 163 | this.systemProcessExitCodeMapper = systemProcessExitCodeMapper; |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Timeout in milliseconds. |
| 168 | * @param timeout upper limit for how long the execution of the external |
| 169 | * program is allowed to last. |
| 170 | */ |
| 171 | public void setTimeout(long timeout) { |
| 172 | this.timeout = timeout; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * The time interval how often the tasklet will check for termination |
| 177 | * status. |
| 178 | * |
| 179 | * @param checkInterval time interval in milliseconds (1 second by default). |
| 180 | */ |
| 181 | public void setTerminationCheckInterval(long checkInterval) { |
| 182 | this.checkInterval = checkInterval; |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Get a reference to {@link StepExecution} for interrupt checks during |
| 187 | * system command execution. |
| 188 | */ |
| 189 | @Override |
| 190 | public void beforeStep(StepExecution stepExecution) { |
| 191 | this.execution = stepExecution; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Sets the task executor that will be used to execute the system command |
| 196 | * NB! Avoid using a synchronous task executor |
| 197 | */ |
| 198 | public void setTaskExecutor(TaskExecutor taskExecutor) { |
| 199 | this.taskExecutor = taskExecutor; |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * If <code>true</code> tasklet will attempt to interrupt the thread |
| 204 | * executing the system command if {@link #setTimeout(long)} has been |
| 205 | * exceeded or user interrupts the job. <code>false</code> by default |
| 206 | */ |
| 207 | public void setInterruptOnCancel(boolean interruptOnCancel) { |
| 208 | this.interruptOnCancel = interruptOnCancel; |
| 209 | } |
| 210 | |
| 211 | } |