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org.apache.jasper.compiler.Generator Maven / Gradle / Ivy

/*
 * 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 java.beans.*;
import java.net.URLEncoder;
import java.lang.reflect.Method;
import javax.servlet.jsp.tagext.*;
import org.xml.sax.Attributes;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.runtime.JspRuntimeLibrary;
import org.apache.jasper.Constants;

/**
 * Generate Java source from Nodes
 *
 * @author Anil K. Vijendran
 * @author Danno Ferrin
 * @author Mandar Raje
 * @author Rajiv Mordani
 * @author Pierre Delisle
 * @author Kin-man Chung
 * @author Jan Luehe
 * @author Denis Benoit
 */

public class Generator {

    private ServletWriter out;
    private MethodsBuffer methodsBuffer;
    private ErrorDispatcher err;
    private BeanRepository beanInfo;
    private JspCompilationContext ctxt;
    private boolean breakAtLF;
    private PageInfo pageInfo;
    private int maxTagNesting;
    private Vector tagHandlerPoolNames;

    /**
     * @param s the input string
     * @return quoted and escaped string, per Java rule
     */
    private static String quote(String s) {

        if (s == null)
            return "null";

        return '"' + escape( s ) + '"';
    }

    /**
     * @param s the input string
     * @return escaped string, per Java rule
     */
    private 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();
    }

    /**
     * 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 {

            public void visit(Node.PageDirective n) throws JasperException {
                String info = n.getAttributeValue("info");
                if (info == null)
                    return;

                out.printil("public String getServletInfo() {");
                out.pushIndent();
                out.printin("return ");
                out.print  (quote(info));
                out.println(";");
                out.popIndent();
                out.print  ('}');
                out.println();
            }

            public void visit(Node.Declaration n) throws JasperException {
                out.printMultiLn(new String(n.getText()));
                out.println();
            }
        }

        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 custom tag
             * and adds it to the list of tag handler pool names unless it is
             * already contained in it.
             */
            public void visit(Node.CustomTag n) throws JasperException {
                
                String name = createTagHandlerPoolName(n.getPrefix(),
                                                       n.getShortName(),
                                                       n.getAttributes(),
                                                       n.getBody() == null);
                n.setTagHandlerPoolName(name);
                if (!names.contains(name)) {
                    names.add(name);
                }

                visitBody(n);
            }

            /*
             * Creates the name of the tag handler pool whose tag handlers may
             * be (re)used to service this action.
             *
             * @return The name of the tag handler pool
             */
            private String createTagHandlerPoolName(String prefix,
                                                    String shortName,
                                                    Attributes attrs,
                                                    boolean hasEmptyBody) {
                String poolName = null;

                if (prefix.indexOf('-') >= 0)
                    prefix = JspUtil.replace(prefix, '-', "$1");
                if (prefix.indexOf('.') >= 0)
                    prefix = JspUtil.replace(prefix, '.', "$2");

                if (shortName.indexOf('-') >= 0)
                    shortName = JspUtil.replace(shortName, '-', "$1");
                if (shortName.indexOf('.') >= 0)
                    shortName = JspUtil.replace(shortName, '.', "$2");
                if (shortName.indexOf(':') >= 0)
                    shortName = JspUtil.replace(shortName, ':', "$3");

                poolName = "_jspx_tagPool_" + prefix + "_" + shortName;
                if (attrs != null) {
                    String[] attrNames = new String[attrs.getLength()];
                    for (int i=0; i 0) {
                    TagVariableInfo[] tagVarInfos = n.getTagVariableInfos();
                    VariableInfo[] varInfos = n.getVariableInfos();

                    if (varInfos != null) {
                        for (int i=0; i 0) {
            out.printil("JspxState _jspxState = new JspxState();");
        }
*/
        out.printil("JspWriter _jspx_out = null;");
        out.println();

        declareTemporaryScriptingVars(page);
        out.println();

        out.printil("try {");
        out.pushIndent();

        out.printil("_jspxFactory = JspFactory.getDefaultFactory();");

        out.printin("response.setContentType(");
        out.print  (quote(pageInfo.getContentType()));
        out.println(");");

        out.printil("pageContext = _jspxFactory.getPageContext(this, request, response,");
        out.printin("\t\t\t");
        out.print  (quote(pageInfo.getErrorPage()));
        out.print  (", " + pageInfo.isSession());
        out.print  (", " + pageInfo.getBuffer());
        out.print  (", " + pageInfo.isAutoFlush());
        out.println(");");

        out.printil("application = pageContext.getServletContext();");
        out.printil("config = pageContext.getServletConfig();");

        if (pageInfo.isSession())
            out.printil("session = pageContext.getSession();");
        out.printil("out = pageContext.getOut();");
        out.printil("_jspx_out = out;");
        out.println();
    }

    /*
     * Generates the servlet constructor.
     */
    private void generateServletConstructor(String servletClassName) {
        out.printil("public " + servletClassName + "() {");
        out.pushIndent();
        for (int i=0; i: tag prefix
         *   : hashtable containing introspection on tag handlers:
         *              : tag short name
         *              : introspection info of tag handler for 
         *                        tag
         */
        private Hashtable handlerInfos;

        private Hashtable tagVarNumbers;
        private String parent;
        private String pushBodyCountVar;

        private ServletWriter out;
        private MethodsBuffer methodsBuffer;
        private int methodNesting;

        /**
         * Constructor.
         */
        public GenerateVisitor(ServletWriter out,
                               MethodsBuffer methodsBuffer) {
            this.out = out;
            this.methodsBuffer = methodsBuffer;
            methodNesting = 0;
            handlerInfos = new Hashtable();
            tagVarNumbers = new Hashtable();
        }

        /**
         * Returns an attribute value, optionally URL encoded.  If
         * the value is a runtime expression, the result is the string for
         * the expression, otherwise the result is the string literal,
         * quoted and escaped.
         * @param attr An JspAttribute object
         * @param encode true if to be URL encoded
         */
        private String attributeValue(Node.JspAttribute attr, boolean encode) {
            String v = attr.getValue();
            if (v == null)
                return "";

            if (attr.isExpression()) {
                if (encode) {
                    return "java.net.URLEncoder.encode(\"\" + " + v + ")";
                }
                return v;
            } else {
                if (encode) {
                    v = URLEncoder.encode(v);
                }
                return quote(v);
            }
        }

        /**
         * Prints the attribute value specified in the param action, in the
         * form of name=value string.
         *
         * @param n the parent node for the param action nodes.
         */
        private void printParams(Node n, Node.JspAttribute page)
                                                throws JasperException {

            class ParamVisitor extends Node.Visitor {
                String separator;

                ParamVisitor(String separator){
                    this.separator = separator;
                }

                public void visit(Node.ParamAction n) throws JasperException {

                    out.print(" + ");
                    out.print(separator);
                    out.print(" + \"");
                    out.print(n.getAttributeValue("name"));
                    out.print("=\" + ");
                    out.print(attributeValue(n.getValue(), true));

                    // The separator is '&' after the second use
                    separator = "\"&\"";
                }
            }

            String pValue = page.getValue();
            String sep;
            if (page.isExpression()) {
                sep = "((" + pValue + ").indexOf('?')>0? '&': '?')";
            } else {
                sep = pValue.indexOf('?')>0? "\"&\"": "\"?\"";
            }
            if (n.getBody() != null) {
                n.getBody().visit(new ParamVisitor(sep));
            }
        }

        public void visit(Node.Expression n) throws JasperException {
            n.setBeginJavaLine(out.getJavaLine());
            out.printil("out.print(" + new String(n.getText()) + ");");
            n.setEndJavaLine(out.getJavaLine());
        }

        public void visit(Node.Scriptlet n) throws JasperException {
            n.setBeginJavaLine(out.getJavaLine());
            out.printMultiLn(new String(n.getText()));
            out.println();
            n.setEndJavaLine(out.getJavaLine());
        }

        public void visit(Node.IncludeAction n) throws JasperException {

            String flush = n.getAttributeValue("flush");

            boolean isFlush = false;        // default to false;
            if ("true".equals(flush))
                isFlush = true;

            n.setBeginJavaLine(out.getJavaLine());

            out.printin("JspRuntimeLibrary.include(request, response, ");
            out.print(attributeValue(n.getPage(), false));
            printParams(n, n.getPage());
            out.println(", out, " + isFlush + ");");

            n.setEndJavaLine(out.getJavaLine());
        }

        public void visit(Node.ForwardAction n) throws JasperException {
            String page = n.getAttributeValue("page");

            n.setBeginJavaLine(out.getJavaLine());

            out.printil("if (true) {");        // So that javac won't complain about
            out.pushIndent();                // codes after "return"
            out.printin("pageContext.forward(");
            out.print(attributeValue(n.getPage(), false));
            printParams(n, n.getPage());
            out.println(");");
            out.printil((methodNesting > 0)? "return true;": "return;");
            out.popIndent();
            out.printil("}");

            n.setEndJavaLine(out.getJavaLine());
            // XXX Not sure if we can eliminate dead codes after this.
        }

        public void visit(Node.GetProperty n) throws JasperException {
            String name = n.getAttributeValue("name");
            String property = n.getAttributeValue("property");

            n.setBeginJavaLine(out.getJavaLine());

            if (beanInfo.checkVariable(name)) {
                // Bean is defined using useBean, introspect at compile time
                Class bean = beanInfo.getBeanType(name);
                String beanName = bean.getName();
                java.lang.reflect.Method meth =
                    JspRuntimeLibrary.getReadMethod(bean, property);
                String methodName = meth.getName();
                out.printil("out.print(JspRuntimeLibrary.toString(" +
                            "(((" + beanName + ")pageContext.findAttribute(" +
                            "\"" + name + "\"))." + methodName + "())));");
            } else {
                // The object could be a custom action with an associated
                // VariableInfo entry for this name.
                // Get the class name and then introspect at runtime.
                out.printil("out.print(JspRuntimeLibrary.toString" +
                            "(JspRuntimeLibrary.handleGetProperty" +
                            "(pageContext.findAttribute(\"" +
                            name + "\"), \"" + property + "\")));");
            }

            n.setEndJavaLine(out.getJavaLine());
        }

        public void visit(Node.SetProperty n) throws JasperException {
            String name = n.getAttributeValue("name");
            String property = n.getAttributeValue("property");
            String param = n.getAttributeValue("param");
            Node.JspAttribute value = n.getValue();

            n.setBeginJavaLine(out.getJavaLine());

            if ("*".equals(property)){
                out.printil("JspRuntimeLibrary.introspect(" +
                            "pageContext.findAttribute(" +
                            "\"" + name + "\"), request);");
            } else if (value == null) {
                if (param == null)
                    param = property;        // default to same as property
                out.printil("JspRuntimeLibrary.introspecthelper(" +
                            "pageContext.findAttribute(\"" + name + "\"), \"" +
                            property + "\", request.getParameter(\"" + param +
                            "\"), " + "request, \"" + param + "\", false);");
            } else if (value.isExpression()) {
                out.printil("JspRuntimeLibrary.handleSetProperty(" + 
                            "pageContext.findAttribute(\""  + name + "\"), \""
                            + property + "\","); 
                out.print(attributeValue(value, false));
                out.println(");");
            } else {
                out.printil("JspRuntimeLibrary.introspecthelper(" +
                            "pageContext.findAttribute(\"" + name + "\"), \"" +
                            property + "\",");
                out.print(attributeValue(value, false));
                out.println(",null, null, false);");
            }

            n.setEndJavaLine(out.getJavaLine());
        }

        public void visit(Node.UseBean n) throws JasperException {

            String name = n.getAttributeValue ("id");
            String scope = n.getAttributeValue ("scope");
            String klass = n.getAttributeValue ("class");
            String type = n.getAttributeValue ("type");
            Node.JspAttribute beanName = n.getBeanName();

            if (type == null)        // if unspecified, use class as type of bean 
                type = klass;

            String scopename = "PageContext.PAGE_SCOPE"; // Default to page
            String lock = "pageContext";

            if ("request".equals(scope)) {
                scopename = "PageContext.REQUEST_SCOPE";
                lock = "request";
            } else if ("session".equals(scope)) {
                scopename = "PageContext.SESSION_SCOPE";
                lock = "session";
            } else if ("application".equals(scope)) {
                scopename = "PageContext.APPLICATION_SCOPE";
                lock = "application";
            }

            n.setBeginJavaLine(out.getJavaLine());

            // Declare bean
            out.printin(type);
            out.print  (' ');
            out.print  (name);
            out.println(" = null;");

            // Lock while getting or creating bean
            out.printin("synchronized (");
            out.print  (lock);
            out.println(") {");
            out.pushIndent();

            // Locate bean from context
            out.printin(name);
            out.print  (" = (");
            out.print  (type);
            out.print  (") pageContext.getAttribute(");
            out.print  (quote(name));
            out.print  (", ");
            out.print  (scopename);
            out.println(");");

            // Create bean
            /*
             * Check if bean is alredy there
             */
            out.printin("if (");
            out.print  (name);
            out.println(" == null){");
            out.pushIndent();
            if (klass == null && beanName == null) {
                /*
                 * If both class name and beanName is not specified, the bean
                 * must be found locally, otherwise it's an error
                 */
                out.printin("throw new java.lang.InstantiationException(\"bean ");
                out.print  (name);
                out.println(" not found within scope\");");
            } else {
                /*
                 * Instantiate bean if not there
                 */
                String className;
                if (beanName != null) {
                    className = attributeValue(beanName, false);
                }
                else {
                    // Implies klass is not null
                    className = quote(klass);
                }
                out.printil("try {");
                out.pushIndent();
                out.printin(name);
                out.print  (" = (");
                out.print  (type);
                out.print  (") java.beans.Beans.instantiate(");
                out.print  ("this.getClass().getClassLoader(), ");
                out.print  (className);
                out.println(");");
                out.popIndent();
                /*
                 * Note: Beans.instantiate throws ClassNotFoundException
                 * if the bean class is abstract.
                 */
                out.printil("} catch (ClassNotFoundException exc) {");
                out.pushIndent();
                out.printil("throw new InstantiationException(exc.getMessage());");
                out.popIndent();
                out.printil("} catch (Exception exc) {");
                out.pushIndent();
                out.printin("throw new ServletException(");
                out.print  ("\"Cannot create bean of class \" + ");
                out.print  (className);
                out.println(", exc);");
                out.popIndent();
                out.printil("}");        // close of try
                /*
                 * Set attribute for bean in the specified scope
                 */
                out.printin("pageContext.setAttribute(");
                out.print  (quote(name));
                out.print  (", ");
                out.print  (name);
                out.print  (", ");
                out.print  (scopename);
                out.println(");");

                // Only visit the body when bean is instantiated
                visitBody(n);
            }
            out.popIndent();
            out.printil("}");

            // End of lock block
            out.popIndent();
            out.printil("}");

            n.setEndJavaLine(out.getJavaLine());
        }
        
        /**
         * @return a string for the form 'attr = "value"'
         */
        private String makeAttr(String attr, String value) {
            if (value == null)
                return "";

            return " " + attr + "=\"" + value + '\"';
        }

        public void visit(Node.PlugIn n) throws JasperException {

            /**
             * A visitor to handle  in a plugin
             */
            class ParamVisitor extends Node.Visitor {

                private boolean ie;

                ParamVisitor(boolean ie) {
                    this.ie = ie;
                }

                public void visit(Node.ParamAction n) throws JasperException {

                    String name = n.getAttributeValue("name");
                    if (name.equalsIgnoreCase("object"))
                        name = "java_object";
                    else if (name.equalsIgnoreCase ("type"))
                        name = "java_type";

                    n.setBeginJavaLine(out.getJavaLine());
                    if( ie ) {
                        // We want something of the form
                        // out.println( "" );
                        out.printil( "out.write( \"\" );" );
                        out.printil("out.write(\"\\n\");");
                    }
                    else {
                        // We want something of the form
                        // out.print( " blah=\"" + ... + "\"" );
                        out.printil( "out.write( \" " + escape( name ) +
                            "=\\\"\" + " +
                            attributeValue( n.getValue(), false) +
                            " + \"\\\"\" );" );
                    }
                    n.setEndJavaLine(out.getJavaLine());
                }
            }

            String type = n.getAttributeValue("type");
            String code = n.getAttributeValue("code");
            String name = n.getAttributeValue("name");
            Node.JspAttribute height = n.getHeight();
            Node.JspAttribute width = n.getWidth();
            String hspace = n.getAttributeValue("hspace");
            String vspace = n.getAttributeValue("vspace");
            String align = n.getAttributeValue("align");
            String iepluginurl = n.getAttributeValue("iepluginurl");
            String nspluginurl = n.getAttributeValue("nspluginurl");
            String codebase = n.getAttributeValue("codebase");
            String archive = n.getAttributeValue("archive");
            String jreversion = n.getAttributeValue("jreversion");

            if (iepluginurl == null)
                iepluginurl = Constants.IE_PLUGIN_URL;
            if (nspluginurl == null)
                nspluginurl = Constants.NS_PLUGIN_URL;


            n.setBeginJavaLine(out.getJavaLine());
            // IE style plugin
            //