org.apache.jasper.compiler.ELNode Maven / Gradle / Ivy
/*
* 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.compiler;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.jsp.tagext.FunctionInfo;
import org.apache.jasper.JasperException;
/**
* This class defines internal representation for an EL Expression
*
* It currently only defines functions. It can be expanded to define
* all the components of an EL expression, if need to.
*
* @author Kin-man Chung
*/
abstract class ELNode {
public abstract void accept(Visitor v) throws JasperException;
/**
* Child classes
*/
/**
* Represents an EL expression: anything in ${ and }.
*/
public static class Root extends ELNode {
private ELNode.Nodes expr;
private char type;
Root(ELNode.Nodes expr, char type) {
this.expr = expr;
this.type = type;
}
@Override
public void accept(Visitor v) throws JasperException {
v.visit(this);
}
public ELNode.Nodes getExpression() {
return expr;
}
public char getType() {
return type;
}
}
/**
* Represents text outside of EL expression.
*/
public static class Text extends ELNode {
private String text;
Text(String text) {
this.text = text;
}
@Override
public void accept(Visitor v) throws JasperException {
v.visit(this);
}
public String getText() {
return text;
}
}
/**
* Represents anything in EL expression, other than functions, including
* function arguments etc
*/
public static class ELText extends ELNode {
private String text;
ELText(String text) {
this.text = text;
}
@Override
public void accept(Visitor v) throws JasperException {
v.visit(this);
}
public String getText() {
return text;
}
}
/**
* Represents a function
* Currently only include the prefix and function name, but not its
* arguments.
*/
public static class Function extends ELNode {
private String prefix;
private String name;
private String uri;
private FunctionInfo functionInfo;
private String methodName;
private String[] parameters;
Function(String prefix, String name) {
this.prefix = prefix;
this.name = name;
}
@Override
public void accept(Visitor v) throws JasperException {
v.visit(this);
}
public String getPrefix() {
return prefix;
}
public String getName() {
return name;
}
public void setUri(String uri) {
this.uri = uri;
}
public String getUri() {
return uri;
}
public void setFunctionInfo(FunctionInfo f) {
this.functionInfo = f;
}
public FunctionInfo getFunctionInfo() {
return functionInfo;
}
public void setMethodName(String methodName) {
this.methodName = methodName;
}
public String getMethodName() {
return methodName;
}
public void setParameters(String[] parameters) {
this.parameters = parameters;
}
public String[] getParameters() {
return parameters;
}
}
/**
* An ordered list of ELNode.
*/
public static class Nodes {
/* Name used for creating a map for the functions in this
EL expression, for communication to Generator.
*/
String mapName = null; // The function map associated this EL
private List list;
public Nodes() {
list = new ArrayList();
}
public void add(ELNode en) {
list.add(en);
}
/**
* Visit the nodes in the list with the supplied visitor
* @param v The visitor used
*/
public void visit(Visitor v) throws JasperException {
Iterator iter = list.iterator();
while (iter.hasNext()) {
ELNode n = iter.next();
n.accept(v);
}
}
public Iterator iterator() {
return list.iterator();
}
public boolean isEmpty() {
return list.size() == 0;
}
/**
* @return true if the expression contains a ${...}
*/
public boolean containsEL() {
Iterator iter = list.iterator();
while (iter.hasNext()) {
ELNode n = iter.next();
if (n instanceof Root) {
return true;
}
}
return false;
}
public void setMapName(String name) {
this.mapName = name;
}
public String getMapName() {
return mapName;
}
}
/*
* A visitor class for traversing ELNodes
*/
public static class Visitor {
public void visit(Root n) throws JasperException {
n.getExpression().visit(this);
}
@SuppressWarnings("unused")
public void visit(Function n) throws JasperException {
// NOOP by default
}
@SuppressWarnings("unused")
public void visit(Text n) throws JasperException {
// NOOP by default
}
@SuppressWarnings("unused")
public void visit(ELText n) throws JasperException {
// NOOP by default
}
}
}