| /* |
| * Copyright 1999,2004 The Apache Software Foundation. |
| * |
| * 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.apache.jasper.compiler; |
| |
| import java.util.*; |
| import javax.servlet.jsp.tagext.FunctionInfo; |
| import org.apache.jasper.JasperException; |
| |
| /** |
| * This class generates functions mappers for the EL expressions in the page. |
| * Instead of a global mapper, a mapper is used for ecah call to EL |
| * evaluator, thus avoiding the prefix overlapping and redefinition |
| * issues. |
| * |
| * @author Kin-man Chung |
| */ |
| |
| public class ELFunctionMapper { |
| static private int currFunc = 0; |
| private ErrorDispatcher err; |
| StringBuffer ds; // Contains codes to initialize the functions mappers. |
| StringBuffer ss; // Contains declarations of the functions mappers. |
| |
| /** |
| * Creates the functions mappers for all EL expressions in the JSP page. |
| * |
| * @param compiler Current compiler, mainly for accessing error dispatcher. |
| * @param page The current compilation unit. |
| */ |
| public static void map(Compiler compiler, Node.Nodes page) |
| throws JasperException { |
| |
| currFunc = 0; |
| ELFunctionMapper map = new ELFunctionMapper(); |
| map.err = compiler.getErrorDispatcher(); |
| map.ds = new StringBuffer(); |
| map.ss = new StringBuffer(); |
| |
| page.visit(map.new ELFunctionVisitor()); |
| |
| // Append the declarations to the root node |
| String ds = map.ds.toString(); |
| if (ds.length() > 0) { |
| Node root = page.getRoot(); |
| new Node.Declaration(map.ss.toString(), null, root); |
| new Node.Declaration("static {\n" + ds + "}\n", null, root); |
| } |
| } |
| |
| /** |
| * A visitor for the page. The places where EL is allowed are scanned |
| * for functions, and if found functions mappers are created. |
| */ |
| class ELFunctionVisitor extends Node.Visitor { |
| |
| /** |
| * Use a global name map to facilitate reuse of function maps. |
| * The key used is prefix:function:uri. |
| */ |
| private HashMap gMap = new HashMap(); |
| |
| public void visit(Node.ParamAction n) throws JasperException { |
| doMap(n.getValue()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.IncludeAction n) throws JasperException { |
| doMap(n.getPage()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.ForwardAction n) throws JasperException { |
| doMap(n.getPage()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.SetProperty n) throws JasperException { |
| doMap(n.getValue()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.UseBean n) throws JasperException { |
| doMap(n.getBeanName()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.PlugIn n) throws JasperException { |
| doMap(n.getHeight()); |
| doMap(n.getWidth()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.JspElement n) throws JasperException { |
| |
| Node.JspAttribute[] attrs = n.getJspAttributes(); |
| for (int i = 0; attrs != null && i < attrs.length; i++) { |
| doMap(attrs[i]); |
| } |
| doMap(n.getNameAttribute()); |
| visitBody(n); |
| } |
| |
| public void visit(Node.UninterpretedTag n) throws JasperException { |
| |
| Node.JspAttribute[] attrs = n.getJspAttributes(); |
| for (int i = 0; attrs != null && i < attrs.length; i++) { |
| doMap(attrs[i]); |
| } |
| visitBody(n); |
| } |
| |
| public void visit(Node.CustomTag n) throws JasperException { |
| Node.JspAttribute[] attrs = n.getJspAttributes(); |
| for (int i = 0; attrs != null && i < attrs.length; i++) { |
| doMap(attrs[i]); |
| } |
| visitBody(n); |
| } |
| |
| public void visit(Node.ELExpression n) throws JasperException { |
| doMap(n.getEL()); |
| } |
| |
| private void doMap(Node.JspAttribute attr) |
| throws JasperException { |
| if (attr != null) { |
| doMap(attr.getEL()); |
| } |
| } |
| |
| /** |
| * Creates function mappers, if needed, from ELNodes |
| */ |
| private void doMap(ELNode.Nodes el) |
| throws JasperException { |
| |
| // Only care about functions in ELNode's |
| class Fvisitor extends ELNode.Visitor { |
| ArrayList funcs = new ArrayList(); |
| HashMap keyMap = new HashMap(); |
| public void visit(ELNode.Function n) throws JasperException { |
| String key = n.getPrefix() + ":" + n.getName(); |
| if (! keyMap.containsKey(key)) { |
| keyMap.put(key,""); |
| funcs.add(n); |
| } |
| } |
| } |
| |
| if (el == null) { |
| return; |
| } |
| |
| // First locate all unique functions in this EL |
| Fvisitor fv = new Fvisitor(); |
| el.visit(fv); |
| ArrayList functions = fv.funcs; |
| |
| if (functions.size() == 0) { |
| return; |
| } |
| |
| // Reuse a previous map if possible |
| String decName = matchMap(functions); |
| if (decName != null) { |
| el.setMapName(decName); |
| return; |
| } |
| |
| // Generate declaration for the map statically |
| decName = getMapName(); |
| ss.append("static private org.apache.jasper.runtime.ProtectedFunctionMapper " + decName + ";\n"); |
| |
| ds.append(" " + decName + "= "); |
| ds.append("org.apache.jasper.runtime.ProtectedFunctionMapper"); |
| |
| // Special case if there is only one function in the map |
| String funcMethod = null; |
| if (functions.size() == 1) { |
| funcMethod = ".getMapForFunction"; |
| } else { |
| ds.append(".getInstance();\n"); |
| funcMethod = " " + decName + ".mapFunction"; |
| } |
| |
| // Setup arguments for either getMapForFunction or mapFunction |
| for (int i = 0; i < functions.size(); i++) { |
| ELNode.Function f = (ELNode.Function)functions.get(i); |
| FunctionInfo funcInfo = f.getFunctionInfo(); |
| String key = f.getPrefix()+ ":" + f.getName(); |
| ds.append(funcMethod + "(\"" + key + "\", " + |
| funcInfo.getFunctionClass() + ".class, " + |
| '\"' + f.getMethodName() + "\", " + |
| "new Class[] {"); |
| String params[] = f.getParameters(); |
| for (int k = 0; k < params.length; k++) { |
| if (k != 0) { |
| ds.append(", "); |
| } |
| int iArray = params[k].indexOf('['); |
| if (iArray < 0) { |
| ds.append(params[k] + ".class"); |
| } |
| else { |
| String baseType = params[k].substring(0, iArray); |
| ds.append("java.lang.reflect.Array.newInstance("); |
| ds.append(baseType); |
| ds.append(".class,"); |
| |
| // Count the number of array dimension |
| int aCount = 0; |
| for (int jj = iArray; jj < params[k].length(); jj++ ) { |
| if (params[k].charAt(jj) == '[') { |
| aCount++; |
| } |
| } |
| if (aCount == 1) { |
| ds.append("0).getClass()"); |
| } else { |
| ds.append("new int[" + aCount + "]).getClass()"); |
| } |
| } |
| } |
| ds.append("});\n"); |
| // Put the current name in the global function map |
| gMap.put(f.getPrefix() + ':' + f.getName() + ':' + f.getUri(), |
| decName); |
| } |
| el.setMapName(decName); |
| } |
| |
| /** |
| * Find the name of the function mapper for an EL. Reuse a |
| * previously generated one if possible. |
| * @param functions An ArrayList of ELNode.Function instances that |
| * represents the functions in an EL |
| * @return A previous generated function mapper name that can be used |
| * by this EL; null if none found. |
| */ |
| private String matchMap(ArrayList functions) { |
| |
| String mapName = null; |
| for (int i = 0; i < functions.size(); i++) { |
| ELNode.Function f = (ELNode.Function)functions.get(i); |
| String temName = (String) gMap.get(f.getPrefix() + ':' + |
| f.getName() + ':' + f.getUri()); |
| if (temName == null) { |
| return null; |
| } |
| if (mapName == null) { |
| mapName = temName; |
| } else if (!temName.equals(mapName)) { |
| // If not all in the previous match, then no match. |
| return null; |
| } |
| } |
| return mapName; |
| } |
| |
| /* |
| * @return An unique name for a function mapper. |
| */ |
| private String getMapName() { |
| return "_jspx_fnmap_" + currFunc++; |
| } |
| } |
| } |
| |