Quadcap Embeddable Server

com/quadcap/http/servlets/jsp/JspServlet.java

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package com.quadcap.http.servlets.jsp;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;
import java.io.PrintWriter;
import java.io.Reader;

import java.util.Hashtable;
import java.util.Properties;
import java.util.Vector;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.SingleThreadModel;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import javax.servlet.jsp.HttpJspPage;

import org.xml.sax.DocumentHandler;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import com.quadcap.io.HtmlifyWriter;
import com.quadcap.io.NullOutputStream;

import com.quadcap.util.ConfigString;
import com.quadcap.util.Debug;
import com.quadcap.util.Util;

/**
 * "The" JSP Servlet.
 *
 * @author Stan Bailes
 */
public class JspServlet extends HttpServlet {
    ClassLoader                 parentClassLoader;
    ServletConfig               config;
    ServletContext              context;
    File                        repository;
    Hashtable                   pages           = new Hashtable();
    JspClassLoader              classLoader     = null;
    JavaCompiler                javaCompiler    = null;

    public void init(ServletConfig config) throws ServletException {
        new JspFactory();
        super.init(config);
        this.config = config;
        this.context = config.getServletContext();
        this.repository = (File)context.getAttribute("repository");

        // For windows, the classpath needs to be quoted.  So we invent
        // 'wq', the 'windows quote' variable.  sheesh.
        Properties p = new Properties();
        p.putAll(System.getProperties());
        if (File.pathSeparatorChar == ';') {
            p.put("wq", "\"");
        } else {
            p.put("wq", "");
        }

        String jc = config.getInitParameter("compiler");
        if (jc == null || jc.trim().length() == 0) {
            /*{com.quadcap.util.Config-vars.xml-2000}
             * <config-var>
             *   <config-name>jsp.compiler</config-name>
             *   <config-dflt>jikes</config-dflt>
             *   <config-desc>Choices are 'jikes' or 'javac'.</config-desc>
             * </config-var>
             */
            ConfigString cs = ConfigString.find("jsp.compiler", "jikes");
            if (cs != null) jc = cs.toString();
        }
        this.javaCompiler = null;
        if (jc.equalsIgnoreCase("dynamic")) {
            // jikes if possible, otherwise fallback to javac
            if (Util.execCommand("jikes -v",
                                 new NullOutputStream(),
                                 new NullOutputStream()) == -1) {
                jc = "javac";
            } else {
                jc = "jikes";
            }
        }

        if (jc.equalsIgnoreCase("javac")) {
            this.javaCompiler = new Javac();
        } else {
            this.javaCompiler = new JavaCompiler();
        }
        this.javaCompiler.init(getServletContext(),
                               repository,
                               config.getInitParameter("compile." + jc),
                               p);
        this.parentClassLoader =
            (ClassLoader)context.getAttribute("com.quadcap.classLoader");
        if (parentClassLoader == null) {
            this.parentClassLoader = this.getClass().getClassLoader();
        }
        refreshClassLoader();
    }

    void refreshClassLoader() {
        this.classLoader = new JspClassLoader(parentClassLoader, repository);
    }

    protected void service(HttpServletRequest request,
                           HttpServletResponse response) 
        throws IOException, ServletException 
    {
        String name = request.getServletPath();
        response.setContentType("text/html");
        response.setHeader("Expires", "0");

        JspPage page = null;
        try {
            page = getJspPageForName(name, response);
        } catch (JspException e) {
            if (e.getReportedError()) return;
            throw e;
        }
        if (page == null) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND,
                               "Not found: " + request.getRequestURI());
            return;
        }
        if (page instanceof SingleThreadModel) {
            synchronized (page) {
                page._jspService(request, response);
            }
        } else {
            page._jspService(request, response);
        }
    }

    JspPage getJspPageForName(String name, HttpServletResponse response) 
        throws IOException, ServletException 
    {
        JspObject jsp = (JspObject)pages.get(name);
        boolean found = jsp != null;
        if (jsp == null) {
            if (context.getResource(name) == null) {
                return null;
            }
            synchronized (this) {
                jsp = new JspObject(config.getServletContext(), 
                                    repository, name);
            }
        }
        JspPage p = jsp.getJspPage();
        if (p == null || jsp.needRecompile()) {
            if (p != null) {
                unload(p);
                jsp.setJspPage(null);
            }
            loadJspPage(jsp, response);
        }
        if (!found) pages.put(name, jsp);
        return jsp.getJspPage();
    }

    void unload(JspPage page) {
        page.jspDestroy();
        refreshClassLoader();
    }

    static Object compileLock   = new Object();
    
    JspPage loadJspPage(JspObject jsp, HttpServletResponse response) 
        throws IOException, ServletException, JspException
    {
        if (Trace.level() > 1) {
            Debug.println("loadPage(" + jsp.getFullClassName() + ")");
        }
        JspPage page = null;
        try {
            if (jsp.needRecompile()) {
                synchronized (compileLock) {
                    compilePage(jsp, response);
                }
            }
            Class jspClass = classLoader.loadClass(jsp.getFullClassName());
            page = (JspPage)jspClass.newInstance();
            page.init(getServletConfig());
            page.jspInit();
            jsp.setJspPage(page);
        } catch (JspException e) {
            throw e;
        } catch (Throwable t) {
            Debug.print(t);
            throw new ServletException(t.toString());
        }
        return page;
    }

    void compilePage(JspObject jsp, HttpServletResponse response)
        throws IOException, ServletException, ClassNotFoundException
    {
        translatePage(jsp);
        try {
            javaCompiler.compile(jsp.getJavaFile(), jsp.getClassFile());
        } catch (JspException e) {
            File javaFile = jsp.getJavaFile();
            FileReader jr = new FileReader(javaFile);
            LineNumberReader r = new LineNumberReader(jr);
            PrintWriter pw = response.getWriter();
            HtmlifyWriter w = new HtmlifyWriter(pw);
            ByteArrayInputStream bis = new ByteArrayInputStream(e.toString().getBytes());
            DataInputStream dis = new DataInputStream(bis);
            boolean done = false;
            int fl = -1, ll = -1, fc = -1, lc = -1;
            int linep = 0;
            String line = null;
            pw.println("<html><head><title>Compile Error</title>");
            pw.println("<style type=\"text/css\">");
            pw.println(".errMsg {");
            pw.println("  background-color: #202020;");
            pw.println("  color: #ffff00;");
            pw.println("  font-size: bigger;");
            pw.println("}");
            pw.println(".errText {");
            pw.println("  background-color: #80a0c0;");
            pw.println("  color: #000000;");
            pw.println("  font-size: bigger;");
            pw.println("}");
            pw.println("</style>");
            pw.println("</head>");
            pw.println("<body bgcolor=#a0c0e0 text=#000000>");
            pw.print("<h2>Compile Error for ");
            pw.print(jsp.getName());
            pw.println("</h2><pre>");
            String errMsg = "";
            
            while (!done) {
                if (fl < 0) {
                    String errLine = dis.readLine();
                    Debug.println("errLine = " + errLine);
                    if (errLine != null) {
                        try {
                            String eline = errLine;
                            int idx = errLine.indexOf(".java:");
                            if (idx > 0) eline = errLine.substring(idx);
                            Vector v = Util.split(eline, ':');
                            for (int i = 0; i < v.size(); i++) {
                                Debug.println("" + i + ": " + v.elementAt(i));
                            }
                            if (v.size() >= 5) {
                                fl = Integer.parseInt(v.elementAt(1).toString());
                                fc = Integer.parseInt(v.elementAt(2).toString());
                                ll = Integer.parseInt(v.elementAt(3).toString());
                                lc = Integer.parseInt(v.elementAt(4).toString());
                                if (v.size() > 6) {
                                    errMsg = v.elementAt(6).toString();
                                }
                            }
                        } catch (Exception ce) {
                            Debug.print(ce);
                            ll = fl; lc = fc;
                            errMsg = errLine;
                        }
                    } else {
                        fl = fc = ll = lc = -1;
                    }
                }
                while (fl < 0 || r.getLineNumber() < fl) {
                    line = r.readLine();
                    if (r.getLineNumber() == fl) break;
                    if (line == null) {
                        done = true;
                        break;
                    }
                    else {
                        w.println(line);
                        linep = r.getLineNumber();
                    }
                }
                if (done) break;
                if (fl >= 0) {
                    if (linep < r.getLineNumber()) {
                        w.print(substring(line, 0, fc-1));
                        pw.print("<b><span class=\"errText\">");
                        if (ll == r.getLineNumber()) {
                            w.print(substring(line, fc-1, lc));
                            pw.print("</span></b>");
                            w.println(substring(line, lc));
                        } else {
                            w.println(substring(line, fc-1));
                            while (ll < r.getLineNumber()) {
                                line = r.readLine();
                                if (line == null) {
                                    pw.println("</span></b>");
                                    done = true;
                                    break;
                                }
                            }
                            if (done) break;
                            w.print(substring(line, 0, lc));
                            pw.print("</span></b>");
                            w.println(substring(line, lc));
                        }
                        linep = r.getLineNumber();
                    }
                    fl = fc = ll = lc = -1;
                    pw.print("<i><span class=\"errMsg\">");
                    w.println(errMsg);
                    pw.println("</span></i>");
                }
            }
            pw.println("</pre></body></html>");
            e.setReportedError(true);
            throw e;
        }
    }

    static String substring(String s, int f) {
        int len = s.length();
        if (f < 0) f = 0;
        if (f >= len) f = len-1;
        return s.substring(f);
    }

    static String substring(String s, int f, int t) {
        int len = s.length();
        if (f < 0) f = 0;
        if (f >= len) f = len-1;
        if (t < 0) t = 0;
        if (t >= len) t = len-1;
        return s.substring(f, t);
    }

    void translatePage(JspObject jsp) throws IOException, ServletException {
        File javaFile = jsp.getJavaFile();

        if (javaFile.exists()) javaFile.delete();

        FileOutputStream jos = new FileOutputStream(javaFile);
        BufferedOutputStream bos = new BufferedOutputStream(jos);
        PrintWriter w = new PrintWriter(bos);

        try {
            Reader r = jsp.getJspReader();

            try {
                compileJsp(jsp, r, w);
            } finally {
                r.close();
            }
        } finally {
            w.close();
        }
    }

    void compileJsp(JspObject jsp, Reader in, PrintWriter w)
        throws IOException, ServletException 
    {
        try {
            JspParser p = new JspParser();
            JspHandler h = new JspHandler(context, p, w, jsp);
            p.setDocumentHandler(h);
            p.setJspHandler(h);
            p.setEntityResolver(h);
            throw new ServletException(e.toString());
        }
    }

    public void destroy() {
        super.destroy();
    }

    public String getServletInfo() {
        return "Quadcap Jsp Servlet";
    }    
}