jspconfig.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.io.InputStream;
import java.util.Iterator;
import java.util.Vector;
import java.net.URL;

import javax.servlet.ServletContext;

import org.apache.jasper.JasperException;
import org.apache.jasper.xmlparser.ParserUtils;
import org.apache.jasper.xmlparser.TreeNode;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.xml.sax.InputSource;

/**
 * Handles the jsp-config element in WEB_INF/web.xml.  This is used
 * for specifying the JSP configuration information on a JSP page
 *
 * @author Kin-man Chung
 * @author Remy Maucherat
 */

public class JspConfig {

    private static final String WEB_XML = "/WEB-INF/web.xml";

    // Logger
    private Log log = LogFactory.getLog(JspConfig.class);

    private Vector jspProperties = null;
    private ServletContext ctxt;
    private boolean initialized = false;

    private String defaultIsXml = null;		// unspecified
    private String defaultIsELIgnored = null;	// unspecified
    private String defaultIsScriptingInvalid = null;
    private String defaultDeferedSyntaxAllowedAsLiteral = null;
    private String defaultTrimDirectiveWhitespaces = null;
    private JspProperty defaultJspProperty;

    public JspConfig(ServletContext ctxt) {
        this.ctxt = ctxt;
    }

    private double getVersion(TreeNode webApp) {
        String v = webApp.findAttribute("version");
        if (v != null) {
            try {
                return Double.parseDouble(v);
            } catch (NumberFormatException e) {
            }
        }
        return 2.3;
    }

    private void processWebDotXml(ServletContext ctxt) throws JasperException {

        InputStream is = null;

        try {
            URL uri = ctxt.getResource(WEB_XML);
            if (uri == null) {
                // no web.xml
                return;
            }

            is = uri.openStream();
            InputSource ip = new InputSource(is);
            ip.setSystemId(uri.toExternalForm()); 

            ParserUtils pu = new ParserUtils();
            TreeNode webApp = pu.parseXMLDocument(WEB_XML, ip);

            if (webApp == null
                    || getVersion(webApp) < 2.4) {
                defaultIsELIgnored = "true";
                return;
            }
            TreeNode jspConfig = webApp.findChild("jsp-config");
            if (jspConfig == null) {
                return;
            }

            jspProperties = new Vector();
            Iterator jspPropertyList = jspConfig.findChildren("jsp-property-group");
            while (jspPropertyList.hasNext()) {

                TreeNode element = (TreeNode) jspPropertyList.next();
                Iterator list = element.findChildren();

                Vector urlPatterns = new Vector();
                String pageEncoding = null;
                String scriptingInvalid = null;
                String elIgnored = null;
                String isXml = null;
                Vector includePrelude = new Vector();
                Vector includeCoda = new Vector();
                String deferredSyntaxAllowedAsLiteral = null;
                String trimDirectiveWhitespaces = null;

                while (list.hasNext()) {

                    element = (TreeNode) list.next();
                    String tname = element.getName();

                    if ("url-pattern".equals(tname))
                        urlPatterns.addElement( element.getBody() );
                    else if ("page-encoding".equals(tname))
                        pageEncoding = element.getBody();
                    else if ("is-xml".equals(tname))
                        isXml = element.getBody();
                    else if ("el-ignored".equals(tname))
                        elIgnored = element.getBody();
                    else if ("scripting-invalid".equals(tname))
                        scriptingInvalid = element.getBody();
                    else if ("include-prelude".equals(tname))
                        includePrelude.addElement(element.getBody());
                    else if ("include-coda".equals(tname))
                        includeCoda.addElement(element.getBody());
                    else if ("deferred-syntax-allowed-as-literal".equals(tname))
                        deferredSyntaxAllowedAsLiteral = element.getBody();
                    else if ("trim-directive-whitespaces".equals(tname))
                        trimDirectiveWhitespaces = element.getBody();
                }

                if (urlPatterns.size() == 0) {
                    continue;
                }

                // Add one JspPropertyGroup for each URL Pattern.  This makes
                // the matching logic easier.
                for( int p = 0; p < urlPatterns.size(); p++ ) {
                    String urlPattern = (String)urlPatterns.elementAt( p );
                    String path = null;
                    String extension = null;

                    if (urlPattern.indexOf('*') < 0) {
                        // Exact match
                        path = urlPattern;
                    } else {
                        int i = urlPattern.lastIndexOf('/');
                        String file;
                        if (i >= 0) {
                            path = urlPattern.substring(0,i+1);
                            file = urlPattern.substring(i+1);
                        } else {
                            file = urlPattern;
                        }

                        // pattern must be "*", or of the form "*.jsp"
                        if (file.equals("*")) {
                            extension = "*";
                        } else if (file.startsWith("*.")) {
                            extension = file.substring(file.indexOf('.')+1);
                        }

                        // The url patterns are reconstructed as the follwoing:
                        // path != null, extension == null:  / or /foo/bar.ext
                        // path == null, extension != null:  *.ext
                        // path != null, extension == "*":   /foo/*
                        boolean isStar = "*".equals(extension);
                        if ((path == null && (extension == null || isStar))
                                || (path != null && !isStar)) {
                            if (log.isWarnEnabled()) {
                                log.warn(Localizer.getMessage(
                                        "jsp.warning.bad.urlpattern.propertygroup",
                                        urlPattern));
                            }
                            continue;
                        }
                    }

                    JspProperty property = new JspProperty(isXml,
                            elIgnored,
                            scriptingInvalid,
                            pageEncoding,
                            includePrelude,
                            includeCoda,
                            deferredSyntaxAllowedAsLiteral,
                            trimDirectiveWhitespaces);
                    JspPropertyGroup propertyGroup =
                        new JspPropertyGroup(path, extension, property);

                    jspProperties.addElement(propertyGroup);
                }
            }
        } catch (Exception ex) {
            throw new JasperException(ex);
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (Throwable t) {}
            }
        }
    }

    private void init() throws JasperException {

        if (!initialized) {
            processWebDotXml(ctxt);
            defaultJspProperty = new JspProperty(defaultIsXml,
                    defaultIsELIgnored,
                    defaultIsScriptingInvalid,
                    null, null, null, defaultDeferedSyntaxAllowedAsLiteral, 
                    defaultTrimDirectiveWhitespaces);
            initialized = true;
        }
    }

    /**
     * Select the property group that has more restrictive url-pattern.
     * In case of tie, select the first.
     */
    private JspPropertyGroup selectProperty(JspPropertyGroup prev,
            JspPropertyGroup curr) {
        if (prev == null) {
            return curr;
        }
        if (prev.getExtension() == null) {
            // exact match
            return prev;
        }
        if (curr.getExtension() == null) {
            // exact match
            return curr;
        }
        String prevPath = prev.getPath();
        String currPath = curr.getPath();
        if (prevPath == null && currPath == null) {
            // Both specifies a *.ext, keep the first one
            return prev;
        }
        if (prevPath == null && currPath != null) {
            return curr;
        }
        if (prevPath != null && currPath == null) {
            return prev;
        }
        if (prevPath.length() >= currPath.length()) {
            return prev;
        }
        return curr;
    }


    /**