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Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/TaskConfigurationChecker.java')
-rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/TaskConfigurationChecker.java | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/TaskConfigurationChecker.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/TaskConfigurationChecker.java new file mode 100644 index 00000000..e8e74441 --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/TaskConfigurationChecker.java @@ -0,0 +1,111 @@ +/* + * 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 org.apache.tools.ant; + +import java.util.ArrayList; +import java.util.List; + +/** + * <p>Helper class for the check of the configuration of a given task. + * This class provides methods for making assumptions about the task configuration. + * After collecting all violations with <tt>assert*</tt> and <tt>fail</tt> + * methods the <tt>checkErrors</tt> will throw a BuildException with all collected + * messages or does nothing if there wasn't any error.</p> + * + * <p>Example:</p> + * + * <pre> + * public class MyTask extends Task { + * ... + * public void execute() { + * TaskConfigurationChecker checker = TaskConfigurationChecker(this); + * checker.assertConfig( + * srcdir != null, + * "Attribute 'srcdir' must be set. + * ); + * checker.assertConfig( + * srcdir.exists(), + * "Srcdir (" + srcdir + ") must exist." + * ); + * if (someComplexCondition()) { + * fail("Complex condition failed."); + * } + * checker.checkErrors(); + * } + * } + * </pre> + * + * @see <a href="http://martinfowler.com/eaaDev/Notification.html">Notification Pattern</a> + */ +public class TaskConfigurationChecker { + + /** List of all collected error messages. */ + private List<String> errors = new ArrayList<String>(); + + /** Task for which the configuration should be checked. */ + private final Task task; + + /** + * Constructor. + * @param task which task should be checked + */ + public TaskConfigurationChecker(Task task) { + this.task = task; + } + + /** + * Asserts that a condition is true. + * @param condition which condition to check + * @param errormessage errormessage to throw if a condition failed + */ + public void assertConfig(boolean condition, String errormessage) { + if (!condition) { + errors.add(errormessage); + } + } + + /** + * Registers an error. + * @param errormessage the message for the registered error + */ + public void fail(String errormessage) { + errors.add(errormessage); + } + + /** + * Checks if there are any collected errors and throws a BuildException + * with all messages if there was one or more. + * @throws BuildException if one or more errors were registered + */ + public void checkErrors() throws BuildException { + if (!errors.isEmpty()) { + StringBuffer sb = new StringBuffer(); + sb.append("Configurationerror on <"); + sb.append(task.getTaskName()); + sb.append(">:"); + sb.append(System.getProperty("line.separator")); + for (String msg : errors) { + sb.append("- "); + sb.append(msg); + sb.append(System.getProperty("line.separator")); + } + throw new BuildException(sb.toString(), task.getLocation()); + } + } + +} |