001 // Copyright 2004, 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.hivemind.conditional; 016 017 import org.apache.hivemind.ApplicationRuntimeException; 018 import org.apache.hivemind.ClassResolver; 019 import org.apache.hivemind.util.Defense; 020 021 /** 022 * @author Howard M. Lewis Ship 023 */ 024 public class EvaluationContextImpl implements EvaluationContext 025 { 026 private ClassResolver _resolver; 027 028 public EvaluationContextImpl(ClassResolver resolver) 029 { 030 Defense.notNull(resolver, "resolver"); 031 032 _resolver = resolver; 033 } 034 035 public boolean isPropertySet(String propertyName) 036 { 037 return Boolean.getBoolean(propertyName); 038 } 039 040 public boolean doesClassExist(String className) 041 { 042 try 043 { 044 _resolver.findClass(className); 045 046 return true; 047 } 048 catch (ApplicationRuntimeException ex) 049 { 050 return false; 051 } 052 } 053 054 }