/*
* 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 Param implements TagPlugin {
public void doTag(TagPluginContext ctxt) {
//don't support the body content
//define names of all the temp variables
String nameName = ctxt.getTemporaryVariableName();
String valueName = ctxt.getTemporaryVariableName();
String urlName = ctxt.getTemporaryVariableName();
String encName = ctxt.getTemporaryVariableName();
String index = ctxt.getTemporaryVariableName();
//if the param tag has no parents, throw a exception
TagPluginContext parent = ctxt.getParentContext();
if(parent == null){
ctxt.generateJavaSource(" throw new JspTagExcption" +
"(\"<param> outside <import> or <urlEncode>\");");
return;
}
//get the url string before adding this param
ctxt.generateJavaSource("String " + urlName + " = " +
"(String)pageContext.getAttribute(\"url_without_param\");");
//get the value of "name"
ctxt.generateJavaSource("String " + nameName + " = ");
ctxt.generateAttribute("name");
ctxt.generateJavaSource(";");
//if the "name" is null then do nothing.
//else add such string "name=value" to the url.
//and the url should be encoded
ctxt.generateJavaSource("if(" + nameName + " != null && !" + nameName + ".equals(\"\")){");
ctxt.generateJavaSource(" String " + valueName + " = ");
ctxt.generateAttribute("value");
ctxt.generateJavaSource(";");
ctxt.generateJavaSource(" if(" + valueName + " == null) " + valueName + " = \"\";");
ctxt.generateJavaSource(" String " + encName + " = pageContext.getResponse().getCharacterEncoding();");
ctxt.generateJavaSource(" " + nameName + " = java.net.URLEncoder.encode(" + nameName + ", " + encName + ");");
ctxt.generateJavaSource(" " + valueName + " = java.net.URLEncoder.encode(" + valueName + ", " + encName + ");");
ctxt.generateJavaSource(" int " + index + ";");
ctxt.generateJavaSource(" " + index + " = " + urlName + ".indexOf(\'?\');");
//if the current param is the first one, add a "?" ahead of it
//else add a "&" ahead of it
ctxt.generateJavaSource(" if(" + index + " == -1){");
ctxt.generateJavaSource(" " + urlName + " = " + urlName + " + \"?\" + " + nameName + " + \"=\" + " + valueName + ";");
ctxt.generateJavaSource(" }else{");
ctxt.generateJavaSource(" " + urlName + " = " + urlName + " + \"&\" + " + nameName + " + \"=\" + " + valueName + ";");
ctxt.generateJavaSource(" }");
ctxt.generateJavaSource(" pageContext.setAttribute(\"url_without_param\"," + urlName + ");");
ctxt.generateJavaSource("}");
}
}