ErrorDispatcher.java
/*
* 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.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.xml.sax.SAXException;
/**
* Class responsible for dispatching JSP parse and javac compilation errors to the configured error handler.
* <p>
* This class is also responsible for localizing any error codes before they are passed on to the configured error
* handler.
* <p>
* In the case of a Java compilation error, the compiler error message is parsed into an array of JavacErrorDetail
* instances, which is passed on to the configured error handler.
*
* @author Jan Luehe
* @author Kin-man Chung
*/
public class ErrorDispatcher {
/**
* Custom error handler
*/
private final ErrorHandler errHandler;
/**
* Indicates whether the compilation was initiated by JspServlet or JspC
*/
private final boolean jspcMode;
/**
* Constructor.
*
* @param jspcMode true if compilation has been initiated by JspC, false otherwise
*/
public ErrorDispatcher(boolean jspcMode) {
// XXX check web.xml for custom error handler
errHandler = new DefaultErrorHandler();
this.jspcMode = jspcMode;
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param errCode Error code
* @param args Arguments for parametric replacement
*
* @throws JasperException An error occurred
*/
public void jspError(String errCode, String... args) throws JasperException {
dispatch(null, errCode, args, null);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param where Error location
* @param errCode Error code
* @param args Arguments for parametric replacement
*
* @throws JasperException An error occurred
*/
public void jspError(Mark where, String errCode, String... args) throws JasperException {
dispatch(where, errCode, args, null);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param n Node that caused the error
* @param errCode Error code
* @param args Arguments for parametric replacement
*
* @throws JasperException An error occurred
*/
public void jspError(Node n, String errCode, String... args) throws JasperException {
dispatch(n.getStart(), errCode, args, null);
}
/**
* Dispatches the given parsing exception to the configured error handler.
*
* @param e Parsing exception
*
* @throws JasperException An error occurred
*/
public void jspError(Exception e) throws JasperException {
dispatch(null, null, null, e);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param errCode Error code
* @param args Arguments for parametric replacement
* @param e Parsing exception
*
* @throws JasperException An error occurred
*/
public void jspError(Exception e, String errCode, String... args) throws JasperException {
dispatch(null, errCode, args, e);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param where Error location
* @param e Parsing exception
* @param errCode Error code
* @param args Arguments for parametric replacement
*
* @throws JasperException An error occurred
*/
public void jspError(Mark where, Exception e, String errCode, String... args) throws JasperException {
dispatch(where, errCode, args, e);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param n Node that caused the error
* @param e Parsing exception
* @param errCode Error code
* @param args Arguments for parametric replacement
*
* @throws JasperException An error occurred
*/
public void jspError(Node n, Exception e, String errCode, String... args) throws JasperException {
dispatch(n.getStart(), errCode, args, e);
}
/**
* Parses the given error message into an array of javac compilation error messages (one per javac compilation error
* line number).
*
* @param errMsg Error message
* @param fname Name of Java source file whose compilation failed
* @param page Node representation of JSP page from which the Java source file was generated
*
* @return Array of javac compilation errors, or null if the given error message does not contain any compilation
* error line numbers
*
* @throws JasperException An error occurred
* @throws IOException IO error which usually should not occur
*/
public static JavacErrorDetail[] parseJavacErrors(String errMsg, String fname, Node.Nodes page)
throws JasperException, IOException {
return parseJavacMessage(errMsg, fname, page);
}
/**
* Dispatches the given javac compilation errors to the configured error handler.
*
* @param javacErrors Array of javac compilation errors
*
* @throws JasperException An error occurred
*/
public void javacError(JavacErrorDetail[] javacErrors) throws JasperException {
errHandler.javacError(javacErrors);
}
/**
* Dispatches the given compilation error report and exception to the configured error handler.
*
* @param errorReport Compilation error report
* @param e Compilation exception
*
* @throws JasperException An error occurred
*/
public void javacError(String errorReport, Exception e) throws JasperException {
errHandler.javacError(errorReport, e);
}
/**
* Dispatches the given JSP parse error to the configured error handler. The given error code is localized. If it is
* not found in the resource bundle for localized error messages, it is used as the error message.
*
* @param where Error location
* @param errCode Error code
* @param args Arguments for parametric replacement
* @param e Parsing exception
*
* @throws JasperException An error occurred
*/
private void dispatch(Mark where, String errCode, Object[] args, Exception e) throws JasperException {
String file = null;
String errMsg = null;
int line = -1;
int column = -1;
boolean hasLocation = false;
// Localize
if (errCode != null) {
errMsg = Localizer.getMessage(errCode, args);
} else if (e != null) {
// give a hint about what's wrong
errMsg = e.getMessage();
}
// Get error location
if (where != null) {
if (jspcMode) {
// Get the full URL of the resource that caused the error
try {
URL url = where.getURL();
if (url != null) {
file = url.toString();
} else {
// Fallback to using context-relative path
file = where.getFile();
}
} catch (MalformedURLException me) {
// Fallback to using context-relative path
file = where.getFile();
}
} else {
// Get the context-relative resource path, so as to not disclose any local file system details
file = where.getFile();
}
line = where.getLineNumber();
column = where.getColumnNumber();
hasLocation = true;
}
// Get nested exception
Exception nestedEx = e;
if ((e instanceof SAXException) && (((SAXException) e).getException() != null)) {
nestedEx = ((SAXException) e).getException();
}
if (hasLocation) {
errHandler.jspError(file, line, column, errMsg, nestedEx);
} else {
errHandler.jspError(errMsg, nestedEx);
}
}
/**
* Parses the given Java compilation error message, which may contain one or more compilation errors, into an array
* of JavacErrorDetail instances.
* <p>
* Each JavacErrorDetail instance contains the information about a single compilation error.
*
* @param errMsg Compilation error message that was generated by the javac compiler
* @param fname Name of Java source file whose compilation failed
* @param page Node representation of JSP page from which the Java source file was generated
*
* @return Array of JavacErrorDetail instances corresponding to the compilation errors
*
* @throws JasperException An error occurred
* @throws IOException IO error which usually should not occur
*/
private static JavacErrorDetail[] parseJavacMessage(String errMsg, String fname, Node.Nodes page)
throws IOException, JasperException {
List<JavacErrorDetail> errors = new ArrayList<>();
StringBuilder errMsgBuf = null;
int lineNum = -1;
JavacErrorDetail javacError = null;
BufferedReader reader = new BufferedReader(new StringReader(errMsg));
/*
* Parse compilation errors. Each compilation error consists of a file path and error line number, followed by a
* number of lines describing the error.
*/
String line = null;
while ((line = reader.readLine()) != null) {
/*
* Error line number is delimited by set of colons. Ignore colon following drive letter on Windows
* (fromIndex = 2).
*
* XXX Handle deprecation warnings that don't have line info
*/
int beginColon = line.indexOf(':', 2);
int endColon = line.indexOf(':', beginColon + 1);
if ((beginColon >= 0) && (endColon >= 0)) {
if (javacError != null) {
// add previous error to error vector
errors.add(javacError);
}
String lineNumStr = line.substring(beginColon + 1, endColon);
try {
lineNum = Integer.parseInt(lineNumStr);
} catch (NumberFormatException e) {
lineNum = -1;
}
errMsgBuf = new StringBuilder();
javacError = createJavacError(fname, page, errMsgBuf, lineNum);
}
// Ignore messages preceding first error
if (errMsgBuf != null) {
errMsgBuf.append(line);
errMsgBuf.append(System.lineSeparator());
}
}
// Add last error to error vector
if (javacError != null) {
errors.add(javacError);
}
reader.close();
JavacErrorDetail[] errDetails = null;
if (errors.size() > 0) {
errDetails = errors.toArray(new JavacErrorDetail[0]);
}
return errDetails;
}
/**
* Create a compilation error.
*
* @param fname The file name
* @param page The page nodes
* @param errMsgBuf The error message
* @param lineNum The source line number of the error
*
* @return JavacErrorDetail The error details
*
* @throws JasperException An error occurred
*/
public static JavacErrorDetail createJavacError(String fname, Node.Nodes page, StringBuilder errMsgBuf, int lineNum)
throws JasperException {
return createJavacError(fname, page, errMsgBuf, lineNum, null);
}
/**
* Create a compilation error.
*
* @param fname The file name
* @param page The page nodes
* @param errMsgBuf The error message
* @param lineNum The source line number of the error
* @param ctxt The compilation context
*
* @return JavacErrorDetail The error details
*
* @throws JasperException An error occurred
*/
public static JavacErrorDetail createJavacError(String fname, Node.Nodes page, StringBuilder errMsgBuf, int lineNum,
JspCompilationContext ctxt) throws JasperException {
JavacErrorDetail javacError;
// Attempt to map javac error line number to line in JSP page
ErrorVisitor errVisitor = new ErrorVisitor(lineNum);
page.visit(errVisitor);
Node errNode = errVisitor.getJspSourceNode();
if ((errNode != null) && (errNode.getStart() != null)) {
// If this is a scriplet node then there is a one to one mapping between JSP lines and Java lines
if (errVisitor.getJspSourceNode() instanceof Node.Scriptlet ||
errVisitor.getJspSourceNode() instanceof Node.Declaration) {
javacError = new JavacErrorDetail(fname, lineNum, errNode.getStart().getFile(),
errNode.getStart().getLineNumber() + lineNum - errVisitor.getJspSourceNode().getBeginJavaLine(),
errMsgBuf, ctxt);
} else {
javacError = new JavacErrorDetail(fname, lineNum, errNode.getStart().getFile(),
errNode.getStart().getLineNumber(), errMsgBuf, ctxt);
}
} else {
/*
* javac error line number cannot be mapped to JSP page line number. For example, this is the case if a
* scriptlet is missing a closing brace, which causes havoc with the try-catch-finally block that the code
* generator places around all generated code: As a result of this, the javac error line numbers will be
* outside the range of begin and end java line numbers that were generated for the scriptlet, and therefore
* cannot be mapped to the start line number of the scriptlet in the JSP page.
*
* Include just the javac error info in the error detail.
*/
javacError = new JavacErrorDetail(fname, lineNum, errMsgBuf);
}
return javacError;
}
/**
* Visitor responsible for mapping a line number in the generated servlet source code to the corresponding JSP node.
*/
private static class ErrorVisitor extends Node.Visitor {
/**
* Java source line number to be mapped
*/
private final int lineNum;
/**
* JSP node whose Java source code range in the generated servlet contains the Java source line number to be
* mapped
*/
private Node found;
/**
* Constructor.
*
* @param lineNum Source line number in the generated servlet code
*/
ErrorVisitor(int lineNum) {
this.lineNum = lineNum;
}
@Override
public void doVisit(Node n) throws JasperException {
if ((lineNum >= n.getBeginJavaLine()) && (lineNum < n.getEndJavaLine())) {
found = n;
}
}
/**
* Gets the JSP node to which the source line number in the generated servlet code was mapped.
*
* @return JSP node to which the source line number in the generated servlet code was mapped
*/
public Node getJspSourceNode() {
return found;
}
}
}