/*
* Copyright 2006-2013 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
*
* 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 org.springframework.batch.core.step.tasklet;
import java.io.File;
import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.core.ExitStatus;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobInterruptedException;
import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.explore.JobExplorer;
import org.springframework.batch.core.listener.StepExecutionListenerSupport;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.task.SimpleAsyncTaskExecutor;
import org.springframework.core.task.TaskExecutor;
import org.springframework.util.Assert;
/**
* {@link Tasklet} that executes a system command.
*
* The system command is executed asynchronously using injected
* {@link #setTaskExecutor(TaskExecutor)} - timeout value is required to be set,
* so that the batch job does not hang forever if the external process hangs.
*
* Tasklet periodically checks for termination status (i.e.
* {@link #setCommand(String)} finished its execution or
* {@link #setTimeout(long)} expired or job was interrupted). The check interval
* is given by {@link #setTerminationCheckInterval(long)}.
*
* When job interrupt is detected tasklet's execution is terminated immediately
* by throwing {@link JobInterruptedException}.
*
* {@link #setInterruptOnCancel(boolean)} specifies whether the tasklet should
* attempt to interrupt the thread that executes the system command if it is
* still running when tasklet exits (abnormally).
*
* @author Robert Kasanicky
* @author Will Schipp
*/
public class SystemCommandTasklet extends StepExecutionListenerSupport implements StoppableTasklet, InitializingBean {
protected static final Log logger = LogFactory.getLog(SystemCommandTasklet.class);
private String command;
private String[] environmentParams = null;
private File workingDirectory = null;
private SystemProcessExitCodeMapper systemProcessExitCodeMapper = new SimpleSystemProcessExitCodeMapper();
private long timeout = 0;
private long checkInterval = 1000;
private StepExecution execution = null;
private TaskExecutor taskExecutor = new SimpleAsyncTaskExecutor();
private boolean interruptOnCancel = false;
private volatile boolean stopped = false;
private JobExplorer jobExplorer;
private boolean stoppable = false;
/**
* Execute system command and map its exit code to {@link ExitStatus} using
* {@link SystemProcessExitCodeMapper}.
*/
@Override
public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
FutureTask<Integer> systemCommandTask = new FutureTask<Integer>(new Callable<Integer>() {
@Override
public Integer call() throws Exception {
Process process = Runtime.getRuntime().exec(command, environmentParams, workingDirectory);
return process.waitFor();
}
});
long t0 = System.currentTimeMillis();
taskExecutor.execute(systemCommandTask);
while (true) {
Thread.sleep(checkInterval);//moved to the end of the logic
if(stoppable) {
JobExecution jobExecution =
jobExplorer.getJobExecution(chunkContext.getStepContext().getStepExecution().getJobExecutionId());
if(jobExecution.isStopping()) {
stopped = true;
}
}
if (systemCommandTask.isDone()) {
contribution.setExitStatus(systemProcessExitCodeMapper.getExitStatus(systemCommandTask.get()));
return RepeatStatus.FINISHED;
}
else if (System.currentTimeMillis() - t0 > timeout) {
systemCommandTask.cancel(interruptOnCancel);
throw new SystemCommandException("Execution of system command did not finish within the timeout");
}
else if (execution.isTerminateOnly()) {
systemCommandTask.cancel(interruptOnCancel);
throw new JobInterruptedException("Job interrupted while executing system command '" + command + "'");
}
else if (stopped) {
systemCommandTask.cancel(interruptOnCancel);
contribution.setExitStatus(ExitStatus.STOPPED);
return RepeatStatus.FINISHED;
}
}
}
/**
* @param command command to be executed in a separate system process
*/
public void setCommand(String command) {
this.command = command;
}
/**
* @param envp environment parameter values, inherited from parent process
* when not set (or set to null).
*/
public void setEnvironmentParams(String[] envp) {
this.environmentParams = envp;
}
/**
* @param dir working directory of the spawned process, inherited from
* parent process when not set (or set to null).
*/
public void setWorkingDirectory(String dir) {
if (dir == null) {
this.workingDirectory = null;
return;
}
this.workingDirectory = new File(dir);
Assert.isTrue(workingDirectory.exists(), "working directory must exist");
Assert.isTrue(workingDirectory.isDirectory(), "working directory value must be a directory");
}
@Override
public void afterPropertiesSet() throws Exception {
Assert.hasLength(command, "'command' property value is required");
Assert.notNull(systemProcessExitCodeMapper, "SystemProcessExitCodeMapper must be set");
Assert.isTrue(timeout > 0, "timeout value must be greater than zero");
Assert.notNull(taskExecutor, "taskExecutor is required");
stoppable = jobExplorer != null;
}
public void setJobExplorer(JobExplorer jobExplorer) {
this.jobExplorer = jobExplorer;
}
/**
* @param systemProcessExitCodeMapper maps system process return value to
* <code>ExitStatus</code> returned by Tasklet.
* {@link SimpleSystemProcessExitCodeMapper} is used by default.
*/
public void setSystemProcessExitCodeMapper(SystemProcessExitCodeMapper systemProcessExitCodeMapper) {
this.systemProcessExitCodeMapper = systemProcessExitCodeMapper;
}
/**
* Timeout in milliseconds.
* @param timeout upper limit for how long the execution of the external
* program is allowed to last.
*/
public void setTimeout(long timeout) {
this.timeout = timeout;
}
/**
* The time interval how often the tasklet will check for termination
* status.
*
* @param checkInterval time interval in milliseconds (1 second by default).
*/
public void setTerminationCheckInterval(long checkInterval) {
this.checkInterval = checkInterval;
}
/**
* Get a reference to {@link StepExecution} for interrupt checks during
* system command execution.
*/
@Override
public void beforeStep(StepExecution stepExecution) {
this.execution = stepExecution;
}
/**
* Sets the task executor that will be used to execute the system command
* NB! Avoid using a synchronous task executor
*/
public void setTaskExecutor(TaskExecutor taskExecutor) {
this.taskExecutor = taskExecutor;
}
/**
* If <code>true</code> tasklet will attempt to interrupt the thread
* executing the system command if {@link #setTimeout(long)} has been
* exceeded or user interrupts the job. <code>false</code> by default
*/
public void setInterruptOnCancel(boolean interruptOnCancel) {
this.interruptOnCancel = interruptOnCancel;
}
/**
* Will interrupt the thread executing the system command only if
* {@link #setInterruptOnCancel(boolean)} has been set to true. Otherwise
* the underlying command will be allowed to finish before the tasklet
* ends.
*
* @since 3.0
* @see StoppableTasklet#stop()
*/
@Override
public void stop() {
stopped = true;
}
}