All Downloads are FREE. Search and download functionalities are using the official Maven repository.

freemarker.template.utility.Execute Maven / Gradle / Ivy

There is a newer version: 7.0.58
Show newest version
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 freemarker.template.utility;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.List;

import freemarker.template.TemplateModelException;

/**
 * 

Gives FreeMarker the the ability to execute external commands. Will fork * a process, and inline anything that process sends to stdout in the template. * Based on a patch submitted by Peter Molettiere.

* *

BE CAREFUL! this tag, depending on use, may allow you * to set something up so that users of your web * application could run arbitrary code on your server. * This can only happen if you allow unchecked GET/POST * submissions to be used as the command string in the * exec tag.

* *

Usage:
* From java:

*
 * SimpleHash root = new SimpleHash();
 *
 * root.put( "exec", new freemarker.template.utility.Execute() );
 *
 * ...
 * 
* *

From your FreeMarker template:

*
 *
 * The following is executed:
 * ${exec( "/usr/bin/ls" )}
 *
 * ...
 * 
*/ public class Execute implements freemarker.template.TemplateMethodModel { private final static int OUTPUT_BUFFER_SIZE = 1024; /** * Executes a method call. * * @param arguments a List of String objects containing the values * of the arguments passed to the method. * @return the TemplateModel produced by the method, or null. */ @Override public Object exec (List arguments) throws TemplateModelException { String aExecute; StringBuilder aOutputBuffer = new StringBuilder(); if ( arguments.size() < 1 ) { throw new TemplateModelException( "Need an argument to execute" ); } aExecute = (String) (arguments.get(0)); try { Process exec = Runtime.getRuntime().exec( aExecute ); // stdout from the process comes in here try (InputStream execOut = exec.getInputStream()) { Reader execReader = new InputStreamReader(execOut); char[] buffer = new char[OUTPUT_BUFFER_SIZE]; int bytes_read = execReader.read(buffer); while (bytes_read > 0) { aOutputBuffer.append(buffer, 0, bytes_read); bytes_read = execReader.read(buffer); } } } catch ( IOException ioe ) { throw new TemplateModelException( ioe.getMessage() ); } return aOutputBuffer.toString(); } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy