/* * 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 * * 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. */ // // This source code implements specifications defined by the Java // Community Process. In order to remain compliant with the specification // DO NOT add / change / or delete method signatures! // package javax.servlet.jsp.tagext; /** * The auxiliary interface of a Tag, IterationTag or BodyTag tag * handler that wants additional hooks for managing resources. * *
This interface provides two new methods: doCatch(Throwable) * and doFinally(). The prototypical invocation is as follows: * *
* h = get a Tag(); // get a tag handler, perhaps from pool * * h.setPageContext(pc); // initialize as desired * h.setParent(null); * h.setFoo("foo"); * * // tag invocation protocol; see Tag.java * try { * doStartTag()... * .... * doEndTag()... * } catch (Throwable t) { * // react to exceptional condition * h.doCatch(t); * } finally { * // restore data invariants and release per-invocation resources * h.doFinally(); * } * * ... other invocations perhaps with some new setters * ... * h.release(); // release long-term resources **/ public interface TryCatchFinally { /** * Invoked if a Throwable occurs while evaluating the BODY * inside a tag or in any of the following methods: * Tag.doStartTag(), Tag.doEndTag(), * IterationTag.doAfterBody() and BodyTag.doInitBody(). * *
This method is not invoked if the Throwable occurs during * one of the setter methods. * *
This method may throw an exception (the same or a new one) * that will be propagated further up the nest chain. If an exception * is thrown, doFinally() will be invoked. * *
This method is intended to be used to respond to an exceptional * condition. * * @param t The throwable exception navigating through this tag. * @throws Throwable if the exception is to be rethrown further up * the nest chain. */ void doCatch(Throwable t) throws Throwable; /** * Invoked in all cases after doEndTag() for any class implementing * Tag, IterationTag or BodyTag. This method is invoked even if * an exception has occurred in the BODY of the tag, * or in any of the following methods: * Tag.doStartTag(), Tag.doEndTag(), * IterationTag.doAfterBody() and BodyTag.doInitBody(). * *
This method is not invoked if the Throwable occurs during * one of the setter methods. * *
This method should not throw an Exception. * *
This method is intended to maintain per-invocation data * integrity and resource management actions. */ void doFinally(); }