STRUTS2源码解析

/* * 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 java.beans.BeanInfo; import java.beans.IntrospectionException; import java.beans.Introspector; import java.beans.PropertyDescriptor; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Enumeration; import java.util.Hashtable; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Vector; import javax.el.MethodExpression; import javax.el.ValueExpression; import javax.servlet.jsp.tagext.TagAttributeInfo; import javax.servlet.jsp.tagext.TagInfo; import javax.servlet.jsp.tagext.TagVariableInfo; import javax.servlet.jsp.tagext.VariableInfo; import org.apache.struts2.jasper.Constants; import org.apache.struts2.jasper.JasperException; import org.apache.struts2.jasper.JspCompilationContext; import org.apache.struts2.jasper.compiler.Node.NamedAttribute; import org.apache.struts2.jasper.runtime.JspRuntimeLibrary; import org.apache.struts2.JSPRuntime; import org.xml.sax.Attributes; /** * Generate Java source from Nodes * * @author Anil K. Vijendran * @author Danno Ferrin * @author Mandar Raje * @author Rajiv Mordani * @author Pierre Delisle * * Tomcat 4.1.x and Tomcat 5: * @author Kin-man Chung * @author Jan Luehe * @author Shawn Bayern * @author Mark Roth * @author Denis Benoit * * Tomcat 6.x * @author Jacob Hookom * @author Remy Maucherat */ class Generator { private static final Class[] OBJECT_CLASS = { Object.class }; private static final String VAR_EXPRESSIONFACTORY = System.getProperty("org.apache.struts2.jasper.compiler.Generator.VAR_EXPRESSIONFACTORY", "_el_expressionfactory"); private static final String VAR_ANNOTATIONPROCESSOR = System.getProperty("org.apache.struts2.jasper.compiler.Generator.VAR_ANNOTATIONPROCESSOR", "_jsp_annotationprocessor"); private ServletWriter out; private ArrayList methodsBuffered; private FragmentHelperClass fragmentHelperClass; private ErrorDispatcher err; private BeanRepository beanInfo; private JspCompilationContext ctxt; private boolean isPoolingEnabled; private boolean breakAtLF; private String jspIdPrefix; private int jspId; private PageInfo pageInfo; private Vector<String> tagHandlerPoolNames; private GenBuffer charArrayBuffer; /** * @param s * the input string * @return quoted and escaped string, per Java rule */ static String quote(String s) { if (s == null) return "null"; return '"' + escape(s) + '"'; } /** * @param s * the input string * @return escaped string, per Java rule */ static String escape(String s) { if (s == null) return ""; StringBuffer b = new StringBuffer(); for (int i = 0; i < s.length(); i++) { char c = s.charAt(i); if (c == '"') b.append('\\').append('"'); else if (c == '\\') b.append('\\').append('\\'); else if (c == '\n') b.append('\\').append('n'); else if (c == '\r') b.append('\\').append('r'); else b.append(c); } return b.toString(); } /** * Single quote and escape a character */ static String quote(char c) { StringBuffer b = new StringBuffer(); b.append('\''); if (c == '\'') b.append('\\').append('\''); else if (c == '\\') b.append('\\').append('\\'); else if (c == '\n') b.append('\\').append('n'); else if (c == '\r') b.append('\\').append('r'); else b.append(c); b.append('\''); return b.toString(); } private String createJspId() throws JasperException { if (this.jspIdPrefix == null) { StringBuffer sb = new StringBuffer(32); String name = ctxt.getServletJavaFileName(); sb.append("jsp_").append(Math.abs(name.hashCode())).append('_'); this.jspIdPrefix = sb.toString(); } return this.jspIdPrefix + (this.jspId++); } /** * Generates declarations. This includes "info" of the page directive, and * scriptlet declarations. */ private void generateDeclarations(Node.Nodes page) throws JasperException { class DeclarationVisitor extends Node.Visitor { private boolean getServletInfoGenerated = false; /* * Generates getServletInfo() method that returns the value of the * page directive's 'info' attribute, if present. * * The Validator has already ensured that if the translation unit * contains more than one page directive with an 'info' attribute, * their values match. */ public void visit(Node.PageDirective n) throws JasperException { if (getServletInfoGenerated) { return; } String info = n.getAttributeValue("info"); if (info == null) return; getServletInfoGenerated = true; out.printil("public String getServletInfo() {"); out.pushIndent(); out.printin("return "); out.print(quote(info)); out.println(";"); out.popIndent(); out.printil("}"); out.println(); } public void visit(Node.Declaration n) throws JasperException { n.setBeginJavaLine(out.getJavaLine()); out.printMultiLn(new String(n.getText())); out.println(); n.setEndJavaLine(out.getJavaLine()); } // Custom Tags may contain declarations from tag plugins. public void visit(Node.CustomTag n) throws JasperException { if (n.useTagPlugin()) { if (n.getAtSTag() != null) { n.getAtSTag().visit(this); } visitBody(n); if (n.getAtETag() != null) { n.getAtETag().visit(this); } } else { visitBody(n); } } } out.println(); page.visit(new DeclarationVisitor()); } /** * Compiles list of tag handler pool names. */ private void compileTagHandlerPoolList(Node.Nodes page) throws JasperException { class TagHandlerPoolVisitor extends Node.Visitor { private Vector names; /* * Constructor * * @param v Vector of tag handler pool names to populate */ TagHandlerPoolVisitor(Vector v) { names = v; } /* * Gets the name of the tag handler pool for the given cu