content: package act.controller.meta;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * 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.
   * #L%
   */
  
  import act.Act;
  import act.app.App;
  import org.osgl.util.C;
  import org.osgl.util.S;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Unlike other interceptors (Before/After/Finally), Catch interceptor
   * has a special attribute: value, the exception class. Only when the
   * exception thrown out is instance of the class or subclass of the class,
   * the catch interceptor will be executed
   */
  public class CatchMethodMetaInfo extends InterceptorMethodMetaInfo {
      private static final List<String> CATCH_THROWABLE = C.list(Throwable.class.getName());
      private List<String> targetExceptionClassNames = CATCH_THROWABLE;
      private volatile Boolean paramTypeAnalyzed;
  
      protected CatchMethodMetaInfo(CatchMethodMetaInfo copy, ControllerClassMetaInfo clsInfo) {
          super(copy, clsInfo);
          this.targetExceptionClassNames = copy.targetExceptionClassNames;
      }
  
      public CatchMethodMetaInfo(ControllerClassMetaInfo clsInfo) {
          super(clsInfo);
      }
  
      @Override
      protected void releaseResources() {
          targetExceptionClassNames = null;
          super.releaseResources();
      }
  
      public CatchMethodMetaInfo exceptionClasses(List<String> list) {
          targetExceptionClassNames = C.newList(list);
          return this;
      }
  
      public List<String> exceptionClasses() {
          if (null == paramTypeAnalyzed) {
              synchronized (this) {
                  if (null == paramTypeAnalyzed) {
                      paramTypeAnalyzed = true;
                      analyzeParamTypes();
                  }
              }
          }
          return targetExceptionClassNames;
      }
  
      private void analyzeParamTypes() {
          App app = Act.app();
          List<String> paramExceptions = new ArrayList<>();
          for (int i = 0, n = paramCount(); i < n; ++i) {
              HandlerParamMetaInfo param = param(i);
              String className = param.type().getClassName();
              if (className.endsWith("Exception")) {
                  paramExceptions.add(className);
              } else {
                  Class<?> cls = app.classForName(className);
                  if (Throwable.class.isAssignableFrom(cls)) {
                      paramExceptions.add(className);
                  }
              }
          }
          if (!paramExceptions.isEmpty()) {
              if (1 == targetExceptionClassNames.size() && Throwable.class.getName().equals(targetExceptionClassNames.get(0))) {
                  // Since we have param declared exception let's remove the default
                  // Throwable from exception type match list
                  targetExceptionClassNames = paramExceptions;
              } else {
                  targetExceptionClassNames.addAll(paramExceptions);
              }
          }
      }
  
  
      @Override
      public String toString() {
          return toStrBuffer(S.newBuffer()).toString();
      }
  
      @Override
      protected S.Buffer toStrBuffer(S.Buffer sb) {
          StringBuilder prependix = S.builder("catch").append(targetExceptionClassNames).append(" ");
          return super.toStrBuffer(sb).prepend(prependix);
      }
  
      @Override
      protected InterceptorMethodMetaInfo doExtend(ControllerClassMetaInfo clsInfo) {
          return new CatchMethodMetaInfo(this, clsInfo);
      }
  }
  