/* | |
* 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.struts2.jasper.compiler; | |
import org.apache.struts2.jasper.JasperException; | |
import javax.servlet.jsp.tagext.FunctionInfo; | |
import java.util.ArrayList; | |
import java.util.HashMap; | |
/** | |
* This class generates functions mappers for the EL expressions in the page. | |
* Instead of a global mapper, a mapper is used for each call to EL | |
* evaluator, thus avoiding the prefix overlapping and redefinition | |
* issues. | |
* | |
* @author Kin-man Chung | |
*/ | |
public class ELFunctionMapper { | |
private int currFunc = 0; | |
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 { | |
ELFunctionMapper map = new ELFunctionMapper(); | |
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.struts2.jasper.runtime.ProtectedFunctionMapper " + decName + ";\n"); | |
ds.append(" " + decName + "= "); | |
ds.append("org.apache.struts2.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++; | |
} | |
} | |
} | |