| /* |
| * Copyright 2000-2013 JetBrains s.r.o. |
| * |
| * 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 com.intellij.lang.ant.dom; |
| |
| import com.intellij.openapi.util.Pair; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * @author Eugene Zhuravlev |
| * Date: 3/4/13 |
| */ |
| abstract class ClassProvider { |
| static final ClassProvider EMPTY = new ClassProvider() { |
| @Nullable |
| @Override |
| public Class lookupClass() { |
| return null; |
| } |
| |
| @Nullable |
| @Override |
| public String getError() { |
| return null; |
| } |
| }; |
| @Nullable |
| abstract Class lookupClass(); |
| |
| @Nullable |
| abstract String getError(); |
| |
| static ClassProvider create(Class clazz) { |
| return clazz == null? EMPTY : new LoadedClassProvider(clazz); |
| } |
| |
| static ClassProvider create(@Nullable String className, @NotNull ClassLoader loader) { |
| return className == null? EMPTY : new LazyLoadClassProvider(className, loader); |
| } |
| |
| private static final class LoadedClassProvider extends ClassProvider { |
| private final Class myClass; |
| |
| LoadedClassProvider(Class clazz) { |
| myClass = clazz; |
| } |
| |
| @Nullable |
| @Override |
| public Class lookupClass() { |
| return myClass; |
| } |
| |
| @Nullable |
| @Override |
| public String getError() { |
| return null; |
| } |
| } |
| |
| private static final class LazyLoadClassProvider extends ClassProvider { |
| private final String myClassName; |
| private final ClassLoader myClassLoader; |
| private Pair<Class, String> myResult; |
| |
| LazyLoadClassProvider(String className, ClassLoader classLoader) { |
| myClassName = className; |
| myClassLoader = classLoader; |
| } |
| |
| @Override |
| @Nullable |
| public Class lookupClass() { |
| return getResult().getFirst(); |
| } |
| |
| @Override |
| @Nullable |
| public String getError() { |
| return getResult().getSecond(); |
| } |
| |
| @NotNull |
| private Pair<Class, String> getResult() { |
| Pair<Class, String> result = myResult; |
| if (result == null) { |
| Class clazz = null; |
| String error = null; |
| try { |
| clazz = myClassLoader.loadClass(myClassName); |
| } |
| catch (ClassNotFoundException e) { |
| error = "Class not found " + e.getMessage(); |
| } |
| catch (NoClassDefFoundError e) { |
| error = "Class definition not found " + e.getMessage(); |
| } |
| catch (UnsupportedClassVersionError e) { |
| error = "Unsupported class version " + e.getMessage(); |
| } |
| myResult = result = Pair.create(clazz, error); |
| } |
| return result; |
| } |
| } |
| |
| } |