generator.java

业界著名的tomcat服务器的最新6.0的源代码。

                                out.print(" ");
                                out.print(tmpVarName);
                                out.print(" = ");
                                out.print(null);
                                out.println(";");
                            }
                        }
                    } else {
                        for (int i = 0; i < tagVarInfos.length; i++) {
                            String varName = tagVarInfos[i].getNameGiven();
                            if (varName == null) {
                                varName = n.getTagData().getAttributeString(
                                        tagVarInfos[i].getNameFromAttribute());
                            } else if (tagVarInfos[i].getNameFromAttribute() != null) {
                                // alias
                                continue;
                            }
                            String tmpVarName = "_jspx_" + varName + "_"
                                    + n.getCustomNestingLevel();
                            if (!vars.contains(tmpVarName)) {
                                vars.add(tmpVarName);
                                out.printin(tagVarInfos[i].getClassName());
                                out.print(" ");
                                out.print(tmpVarName);
                                out.print(" = ");
                                out.print(null);
                                out.println(";");
                            }
                        }
                    }
                }

                visitBody(n);
            }
        }

        page.visit(new ScriptingVarVisitor());
    }

    /**
     * Generates the _jspInit() method for instantiating the tag handler pools.
     * For tag file, _jspInit has to be invoked manually, and the ServletConfig
     * object explicitly passed.
     * 
     * In JSP 2.1, we also instantiate an ExpressionFactory
     */
    private void generateInit() {

        if (ctxt.isTagFile()) {
            out.printil("private void _jspInit(ServletConfig config) {");
        } else {
            out.printil("public void _jspInit() {");
        }

        out.pushIndent();
        if (isPoolingEnabled) {
            for (int i = 0; i < tagHandlerPoolNames.size(); i++) {
                out.printin(tagHandlerPoolNames.elementAt(i));
                out.print(" = org.apache.jasper.runtime.TagHandlerPool.getTagHandlerPool(");
                if (ctxt.isTagFile()) {
                    out.print("config");
                } else {
                    out.print("getServletConfig()");
                }
                out.println(");");
            }
        }
        
        out.printin(VAR_EXPRESSIONFACTORY);
        out.print(" = _jspxFactory.getJspApplicationContext(");
        if (ctxt.isTagFile()) {
            out.print("config");
        } else {
            out.print("getServletConfig()");
        }
        out.println(".getServletContext()).getExpressionFactory();");

        out.printin(VAR_ANNOTATIONPROCESSOR);
        out.print(" = (org.apache.AnnotationProcessor) ");
        if (ctxt.isTagFile()) {
            out.print("config");
        } else {
            out.print("getServletConfig()");
        }
        out.println(".getServletContext().getAttribute(org.apache.AnnotationProcessor.class.getName());");

        out.popIndent();
        out.printil("}");
        out.println();
    }

    /**
     * Generates the _jspDestroy() method which is responsible for calling the
     * release() method on every tag handler in any of the tag handler pools.
     */
    private void generateDestroy() {

        out.printil("public void _jspDestroy() {");
        out.pushIndent();
        
        if (isPoolingEnabled) {
            for (int i = 0; i < tagHandlerPoolNames.size(); i++) {
                                out.printin((String) tagHandlerPoolNames.elementAt(i));
                                out.println(".release();");
            }
        }
        
        out.popIndent();
        out.printil("}");
        out.println();
    }

    /**
     * Generate preamble package name (shared by servlet and tag handler
     * preamble generation)
     */
    private void genPreamblePackage(String packageName) throws JasperException {
        if (!"".equals(packageName) && packageName != null) {
            out.printil("package " + packageName + ";");
            out.println();
        }
    }

    /**
     * Generate preamble imports (shared by servlet and tag handler preamble
     * generation)
     */
    private void genPreambleImports() throws JasperException {
        Iterator iter = pageInfo.getImports().iterator();
        while (iter.hasNext()) {
            out.printin("import ");
            out.print((String) iter.next());
            out.println(";");
        }

        out.println();
    }

    /**
     * Generation of static initializers in preamble. For example, dependant
     * list, el function map, prefix map. (shared by servlet and tag handler
     * preamble generation)
     */
    private void genPreambleStaticInitializers() throws JasperException {
        out.printil("private static final JspFactory _jspxFactory = JspFactory.getDefaultFactory();");
        out.println();

        // Static data for getDependants()
        out.printil("private static java.util.List _jspx_dependants;");
        out.println();
        List dependants = pageInfo.getDependants();
        Iterator iter = dependants.iterator();
        if (!dependants.isEmpty()) {
            out.printil("static {");
            out.pushIndent();
            out.printin("_jspx_dependants = new java.util.ArrayList(");
            out.print("" + dependants.size());
            out.println(");");
            while (iter.hasNext()) {
                out.printin("_jspx_dependants.add(\"");
                out.print((String) iter.next());
                out.println("\");");
            }
            out.popIndent();
            out.printil("}");
            out.println();
        }
    }

    /**
     * Declare tag handler pools (tags of the same type and with the same
     * attribute set share the same tag handler pool) (shared by servlet and tag
     * handler preamble generation)
     * 
     * In JSP 2.1, we also scope an instance of ExpressionFactory
     */
    private void genPreambleClassVariableDeclarations(String className)
            throws JasperException {
        if (isPoolingEnabled && !tagHandlerPoolNames.isEmpty()) {
            for (int i = 0; i < tagHandlerPoolNames.size(); i++) {
                out.printil("private org.apache.jasper.runtime.TagHandlerPool "
                        + tagHandlerPoolNames.elementAt(i) + ";");
            }
            out.println();
        }
        out.printin("private javax.el.ExpressionFactory ");
        out.print(VAR_EXPRESSIONFACTORY);
        out.println(";");
        out.printin("private org.apache.AnnotationProcessor ");
        out.print(VAR_ANNOTATIONPROCESSOR);
        out.println(";");
        out.println();
    }

    /**
     * Declare general-purpose methods (shared by servlet and tag handler
     * preamble generation)
     */
    private void genPreambleMethods() throws JasperException {
        // Method used to get compile time file dependencies
        out.printil("public Object getDependants() {");
        out.pushIndent();
        out.printil("return _jspx_dependants;");
        out.popIndent();
        out.printil("}");
        out.println();
        
        generateInit();
        generateDestroy();
    }

    /**
     * Generates the beginning of the static portion of the servlet.
     */
    private void generatePreamble(Node.Nodes page) throws JasperException {

        String servletPackageName = ctxt.getServletPackageName();
        String servletClassName = ctxt.getServletClassName();
        String serviceMethodName = Constants.SERVICE_METHOD_NAME;

        // First the package name:
        genPreamblePackage(servletPackageName);

        // Generate imports
        genPreambleImports();

        // Generate class declaration
        out.printin("public final class ");
        out.print(servletClassName);
        out.print(" extends ");
        out.println(pageInfo.getExtends());
        out.printin("    implements org.apache.jasper.runtime.JspSourceDependent");
        if (!pageInfo.isThreadSafe()) {
            out.println(",");
            out.printin("                 SingleThreadModel");
        }
        out.println(" {");
        out.pushIndent();

        // Class body begins here
        generateDeclarations(page);

        // Static initializations here
        genPreambleStaticInitializers();

        // Class variable declarations
        genPreambleClassVariableDeclarations(servletClassName);

        // Constructor
        // generateConstructor(className);

        // Methods here
        genPreambleMethods();

        // Now the service method
        out.printin("public void ");
        out.print(serviceMethodName);
        out.println("(HttpServletRequest request, HttpServletResponse response)");
        out.println("        throws java.io.IOException, ServletException {");

        out.pushIndent();
        out.println();

        // Local variable declarations
        out.printil("PageContext pageContext = null;");

        if (pageInfo.isSession())
            out.printil("HttpSession session = null;");

        if (pageInfo.isErrorPage()) {
            out.printil("Throwable exception = org.apache.jasper.runtime.JspRuntimeLibrary.getThrowable(request);");
            out.printil("if (exception != null) {");
            out.pushIndent();
            out.printil("response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);");
            out.popIndent();
            out.printil("}");
        }

        out.printil("ServletContext application = null;");
        out.printil("ServletConfig config = null;");
        out.printil("JspWriter out = null;");
        out.printil("Object page = this;");

        out.printil("JspWriter _jspx_out = null;");
        out.printil("PageContext _jspx_page_context = null;");
        out.println();

        declareTemporaryScriptingVars(page);
        out.println();

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

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

        if (ctxt.getOptions().isXpoweredBy()) {
            out.printil("response.addHeader(\"X-Powered-By\", \"JSP/2.1\");");
        }

        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("_jspx_page_context = pageContext;");

        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 an XML Prolog, which includes an XML declaration and an XML
     * doctype declaration.
     */
    private void generateXmlProlog(Node.Nodes page) {

        /*
         * An XML declaration is generated under the following conditions: -
         * 'omit-xml-declaration' attribute of <jsp:output> action is set to
         * "no" or "false" - JSP document without a <jsp:root>
         */
        String omitXmlDecl = pageInfo.getOmitXmlDecl();
        if ((omitXmlDecl != null && !JspUtil.booleanValue(omitXmlDecl))
                || (omitXmlDecl == null && page.getRoot().isXmlSyntax()