| /* |
| * Copyright 2000-2009 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 org.jetbrains.idea.maven.server.embedder; |
| |
| import java.lang.reflect.Field; |
| |
| public class FieldAccessor<FIELD_TYPE> { |
| private volatile FIELD_TYPE myWagonManagerCache; |
| private final Class myHostClass; |
| private final Object myHost; |
| private final String myFieldName; |
| |
| public <T> FieldAccessor(Class<? super T> hostClass, T host, String fieldName) { |
| myHostClass = hostClass; |
| myHost = host; |
| myFieldName = fieldName; |
| } |
| |
| public FIELD_TYPE getField() { |
| if (myWagonManagerCache == null) { |
| Object wagon = getFieldValue(myHostClass, myFieldName, myHost); |
| myWagonManagerCache = (FIELD_TYPE)wagon; |
| } |
| return myWagonManagerCache; |
| } |
| |
| private Object getFieldValue(Class c, String fieldName, Object o) { |
| try { |
| Field f = c.getDeclaredField(fieldName); |
| f.setAccessible(true); |
| return f.get(o); |
| } |
| catch (NoSuchFieldException e) { |
| throw new RuntimeException(e); |
| } |
| catch (IllegalAccessException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| } |