jspservletwrapper.java

业界著名的tomcat服务器的最新6.0的源代码。

    public boolean isTagFile() {
	return this.isTagFile;
    }

    public int incTripCount() {
	return tripCount++;
    }

    public int decTripCount() {
	return tripCount--;
    }

    public void service(HttpServletRequest request, 
                        HttpServletResponse response,
                        boolean precompile)
	    throws ServletException, IOException, FileNotFoundException {
        
        try {

            if (ctxt.isRemoved()) {
                throw new FileNotFoundException(jspUri);
            }

            if ((available > 0L) && (available < Long.MAX_VALUE)) {
                response.setDateHeader("Retry-After", available);
                response.sendError
                    (HttpServletResponse.SC_SERVICE_UNAVAILABLE,
                     Localizer.getMessage("jsp.error.unavailable"));
            }

            /*
             * (1) Compile
             */
            if (options.getDevelopment() || firstTime ) {
                synchronized (this) {
                    firstTime = false;

                    // The following sets reload to true, if necessary
                    ctxt.compile();
                }
            } else {
                if (compileException != null) {
                    // Throw cached compilation exception
                    throw compileException;
                }
            }

            /*
             * (2) (Re)load servlet class file
             */
            getServlet();

            // If a page is to be precompiled only, return.
            if (precompile) {
                return;
            }

        } catch (FileNotFoundException ex) {
            ctxt.incrementRemoved();
            String includeRequestUri = (String)
                request.getAttribute("javax.servlet.include.request_uri");
            if (includeRequestUri != null) {
                // This file was included. Throw an exception as
                // a response.sendError() will be ignored by the
                // servlet engine.
                throw new ServletException(ex);
            } else {
                try {
                    response.sendError(HttpServletResponse.SC_NOT_FOUND, 
                                      ex.getMessage());
                } catch (IllegalStateException ise) {
                    log.error(Localizer.getMessage("jsp.error.file.not.found",
                           ex.getMessage()),
                  ex);
                }
            }
        } catch (ServletException ex) {
            if (options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (IOException ex) {
            if (options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (IllegalStateException ex) {
            if (options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (Exception ex) {
            if (options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw new JasperException(ex);
            }
        }

        try {
            
            /*
             * (3) Service request
             */
            if (theServlet instanceof SingleThreadModel) {
               // sync on the wrapper so that the freshness
               // of the page is determined right before servicing
               synchronized (this) {
                   theServlet.service(request, response);
                }
            } else {
                theServlet.service(request, response);
            }

        } catch (UnavailableException ex) {
            String includeRequestUri = (String)
                request.getAttribute("javax.servlet.include.request_uri");
            if (includeRequestUri != null) {
                // This file was included. Throw an exception as
                // a response.sendError() will be ignored by the
                // servlet engine.
                throw ex;
            } else {
                int unavailableSeconds = ex.getUnavailableSeconds();
                if (unavailableSeconds <= 0) {
                    unavailableSeconds = 60;        // Arbitrary default
                }
                available = System.currentTimeMillis() +
                    (unavailableSeconds * 1000L);
                response.sendError
                    (HttpServletResponse.SC_SERVICE_UNAVAILABLE, 
                     ex.getMessage());
            }
        } catch (ServletException ex) {
            if(options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (IOException ex) {
            if(options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (IllegalStateException ex) {
            if(options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw ex;
            }
        } catch (Exception ex) {
            if(options.getDevelopment()) {
                throw handleJspException(ex);
            } else {
                throw new JasperException(ex);
            }
        }
    }

    public void destroy() {
        if (theServlet != null) {
            theServlet.destroy();
            AnnotationProcessor annotationProcessor = (AnnotationProcessor) config.getServletContext().getAttribute(AnnotationProcessor.class.getName());
            if (annotationProcessor != null) {
                try {
                    annotationProcessor.preDestroy(theServlet);
                } catch (Exception e) {
                    // Log any exception, since it can't be passed along
                    log.error(Localizer.getMessage("jsp.error.file.not.found",
                           e.getMessage()), e);
                }
            }
        }
    }

    /**
     * @return Returns the lastModificationTest.
     */
    public long getLastModificationTest() {
        return lastModificationTest;
    }
    /**
     * @param lastModificationTest The lastModificationTest to set.
     */
    public void setLastModificationTest(long lastModificationTest) {
        this.lastModificationTest = lastModificationTest;
    }

    /**
     * <p>Attempts to construct a JasperException that contains helpful information
     * about what went wrong. Uses the JSP compiler system to translate the line
     * number in the generated servlet that originated the exception to a line
     * number in the JSP.  Then constructs an exception containing that
     * information, and a snippet of the JSP to help debugging.
     * Please see http://issues.apache.org/bugzilla/show_bug.cgi?id=37062 and
     * http://www.tfenne.com/jasper/ for more details.
     *</p>
     *
     * @param ex the exception that was the cause of the problem.
     * @return a JasperException with more detailed information
     */
    protected JasperException handleJspException(Exception ex) {
        try {
            Throwable realException = ex;
            if (ex instanceof ServletException) {
                realException = ((ServletException) ex).getRootCause();
            }

            // First identify the stack frame in the trace that represents the JSP
            StackTraceElement[] frames = realException.getStackTrace();
            StackTraceElement jspFrame = null;

            for (int i=0; i<frames.length; ++i) {
                if ( frames[i].getClassName().equals(this.getServlet().getClass().getName()) ) {
                    jspFrame = frames[i];
                    break;
                }
            }

            if (jspFrame == null) {
                // If we couldn't find a frame in the stack trace corresponding
                // to the generated servlet class, we can't really add anything
                return new JasperException(ex);
            }
            else {
                int javaLineNumber = jspFrame.getLineNumber();
                JavacErrorDetail detail = ErrorDispatcher.createJavacError(
                        jspFrame.getMethodName(),
                        this.ctxt.getCompiler().getPageNodes(),
                        null,
                        javaLineNumber,
                        ctxt);

                // If the line number is less than one we couldn't find out
                // where in the JSP things went wrong
                int jspLineNumber = detail.getJspBeginLineNumber();
                if (jspLineNumber < 1) {
                    throw new JasperException(ex);
                }

                if (options.getDisplaySourceFragment()) {
                    return new JasperException(Localizer.getMessage
                            ("jsp.exception", detail.getJspFileName(),
                                    "" + jspLineNumber) +
                                    "\n\n" + detail.getJspExtract() +
                                    "\n\nStacktrace:", ex);
                    
                } else {
                    return new JasperException(Localizer.getMessage
                            ("jsp.exception", detail.getJspFileName(),
                                    "" + jspLineNumber), ex);
                }
            }
        } catch (Exception je) {
            // If anything goes wrong, just revert to the original behaviour
            if (ex instanceof JasperException) {
                return (JasperException) ex;
            } else {
                return new JasperException(ex);
            }
        }
    }

}