| /* |
| * 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. |
| */ |
| |
| |
| package org.apache.jasper.tagplugins.jstl.core; |
| |
| import org.apache.jasper.compiler.tagplugin.TagPlugin; |
| import org.apache.jasper.compiler.tagplugin.TagPluginContext; |
| |
| public class Catch implements TagPlugin { |
| |
| @Override |
| public void doTag(TagPluginContext ctxt) { |
| |
| //flag for the existence of the var attribute |
| boolean hasVar = ctxt.isAttributeSpecified("var"); |
| |
| //temp name for exception and caught |
| String exceptionName = ctxt.getTemporaryVariableName(); |
| String caughtName = ctxt.getTemporaryVariableName(); |
| |
| //main part to generate code |
| ctxt.generateJavaSource("boolean " + caughtName + " = false;"); |
| ctxt.generateJavaSource("try{"); |
| ctxt.generateBody(); |
| ctxt.generateJavaSource("}"); |
| |
| //do catch |
| ctxt.generateJavaSource("catch(Throwable " + exceptionName + "){"); |
| |
| //if the var specified, the exception object should |
| //be set to the attribute "var" defines in page scope |
| if(hasVar){ |
| String strVar = ctxt.getConstantAttribute("var"); |
| ctxt.generateJavaSource(" pageContext.setAttribute(\"" + strVar + "\", " |
| + exceptionName + ", PageContext.PAGE_SCOPE);"); |
| } |
| |
| //whenever there's exception caught, |
| //the flag caught should be set true; |
| ctxt.generateJavaSource(" " + caughtName + " = true;"); |
| ctxt.generateJavaSource("}"); |
| |
| //do finally |
| ctxt.generateJavaSource("finally{"); |
| |
| //if var specified, the attribute it defines |
| //in page scope should be removed |
| if(hasVar){ |
| String strVar = ctxt.getConstantAttribute("var"); |
| ctxt.generateJavaSource(" if(!" + caughtName + "){"); |
| ctxt.generateJavaSource(" pageContext.removeAttribute(\"" + strVar + "\", PageContext.PAGE_SCOPE);"); |
| ctxt.generateJavaSource(" }"); |
| } |
| |
| ctxt.generateJavaSource("}"); |
| } |
| |
| } |