content: /*
   *  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
   *
   *      https://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.taskdefs.condition;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.ProjectComponent;
  
  /**
   * Condition that tests whether a given property has been set.
   *
   * @since Ant 1.5
   */
  public class IsSet extends ProjectComponent implements Condition {
      private String property;
  
      /**
       * Set the property attribute
       *
       * @param p the property name
       */
      public void setProperty(String p) {
          property = p;
      }
  
      /**
       * @return true if the property exists
       * @exception BuildException if the property attribute is not set
       */
      @Override
      public boolean eval() throws BuildException {
          if (property == null) {
              throw new BuildException(
                  "No property specified for isset condition");
          }
          return getProject().getProperty(property) != null;
      }
  
  }
  