Java tutorial
/* * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.xml.transform; import java.lang.reflect.Method; import java.lang.reflect.InvocationTargetException; import java.security.AccessControlContext; import java.security.AccessController; import java.security.CodeSigner; import java.security.CodeSource; import java.security.PermissionCollection; import java.security.Permissions; import java.security.PrivilegedAction; import java.security.ProtectionDomain; import java.util.Objects; /** * This class specifies an exceptional condition that occurred * during the transformation process. * * @since 1.4 */ public class TransformerException extends Exception { private static final long serialVersionUID = 975798773772956428L; /** Field locator specifies where the error occurred */ SourceLocator locator; /** * Method getLocator retrieves an instance of a SourceLocator * object that specifies where an error occurred. * * @return A SourceLocator object, or null if none was specified. */ public SourceLocator getLocator() { return this.locator; } /** * Method setLocator sets an instance of a SourceLocator * object that specifies where an error occurred. * * @param location A SourceLocator object, or null to clear the location. */ public void setLocator(SourceLocator location) { this.locator = location; } /** Field containedException specifies a wrapped exception. May be null. */ Throwable containedException; /** * This method retrieves an exception that this exception wraps. * * @return An Throwable object, or null. * @see #getCause */ public Throwable getException() { return containedException; } /** * Returns the cause of this throwable or <code>null</code> if the * cause is nonexistent or unknown. (The cause is the throwable that * caused this throwable to get thrown.) * @return the cause, or null if unknown */ @Override public Throwable getCause() { return ((containedException == this) ? null : containedException); } /** * Initializes the <i>cause</i> of this throwable to the specified value. * (The cause is the throwable that caused this throwable to get thrown.) * * <p>This method can be called at most once. It is generally called from * within the constructor, or immediately after creating the * throwable. If this throwable was created * with {@link #TransformerException(Throwable)} or * {@link #TransformerException(String,Throwable)}, this method cannot be called * even once. * * @param cause the cause (which is saved for later retrieval by the * {@link #getCause()} method). (A <code>null</code> value is * permitted, and indicates that the cause is nonexistent or * unknown.) * @return a reference to this <code>Throwable</code> instance. * @throws IllegalArgumentException if <code>cause</code> is this * throwable. (A throwable cannot * be its own cause.) * @throws IllegalStateException if this throwable was * created with {@link #TransformerException(Throwable)} or * {@link #TransformerException(String,Throwable)}, or this method has already * been called on this throwable. */ @Override public synchronized Throwable initCause(Throwable cause) { // TransformerException doesn't set its cause (probably // because it predates initCause()) - and we may not want // to change this since Exceptions are serializable... // But this also leads to the broken code in printStackTrace // below... if (this.containedException != null) { throw new IllegalStateException("Can't overwrite cause"); } if (cause == this) { throw new IllegalArgumentException("Self-causation not permitted"); } this.containedException = cause; return this; } /** * Create a new TransformerException. * * @param message The error or warning message. */ public TransformerException(String message) { this(message, null, null); } /** * Create a new TransformerException wrapping an existing exception. * * @param e The exception to be wrapped. */ public TransformerException(Throwable e) { this(null, null, e); } /** * Wrap an existing exception in a TransformerException. * * <p>This is used for throwing processor exceptions before * the processing has started.</p> * * @param message The error or warning message, or null to * use the message from the embedded exception. * @param e Any exception */ public TransformerException(String message, Throwable e) { this(message, null, e); } /** * Create a new TransformerException from a message and a Locator. * * <p>This constructor is especially useful when an application is * creating its own exception from within a DocumentHandler * callback.</p> * * @param message The error or warning message. * @param locator The locator object for the error or warning. */ public TransformerException(String message, SourceLocator locator) { this(message, locator, null); } /** * Wrap an existing exception in a TransformerException. * * @param message The error or warning message, or null to * use the message from the embedded exception. * @param locator The locator object for the error or warning. * @param e Any exception */ public TransformerException(String message, SourceLocator locator, Throwable e) { super(((message == null) || (message.length() == 0)) ? ((e == null) ? "" : e.toString()) : message); this.containedException = e; this.locator = locator; } /** * Get the error message with location information * appended. * * @return A <code>String</code> representing the error message with * location information appended. */ public String getMessageAndLocation() { StringBuilder sbuffer = new StringBuilder(); sbuffer.append(Objects.toString(super.getMessage(), "")); sbuffer.append(Objects.toString(getLocationAsString(), "")); return sbuffer.toString(); } /** * Get the location information as a string. * * @return A string with location info, or null * if there is no location information. */ public String getLocationAsString() { if (locator == null) { return null; } if (System.getSecurityManager() == null) { return getLocationString(); } else { return AccessController.doPrivileged((PrivilegedAction<String>) () -> getLocationString(), new AccessControlContext(new ProtectionDomain[] { getNonPrivDomain() })); } } /** * Constructs the location string. * @return the location string */ private String getLocationString() { if (locator == null) { return null; } StringBuilder sbuffer = new StringBuilder(); String systemID = locator.getSystemId(); int line = locator.getLineNumber(); int column = locator.getColumnNumber(); if (null != systemID) { sbuffer.append("; SystemID: "); sbuffer.append(systemID); } if (0 != line) { sbuffer.append("; Line#: "); sbuffer.append(line); } if (0 != column) { sbuffer.append("; Column#: "); sbuffer.append(column); } return sbuffer.toString(); } /** * Print the the trace of methods from where the error * originated. This will trace all nested exception * objects, as well as this object. */ @Override public void printStackTrace() { printStackTrace(new java.io.PrintWriter(System.err, true)); } /** * Print the the trace of methods from where the error * originated. This will trace all nested exception * objects, as well as this object. * @param s The stream where the dump will be sent to. */ @Override public void printStackTrace(java.io.PrintStream s) { printStackTrace(new java.io.PrintWriter(s)); } /** * Print the the trace of methods from where the error * originated. This will trace all nested exception * objects, as well as this object. * @param s The writer where the dump will be sent to. */ @Override public void printStackTrace(java.io.PrintWriter s) { if (s == null) { s = new java.io.PrintWriter(System.err, true); } try { try { String locInfo = getLocationAsString(); if (null != locInfo) { s.println(locInfo); } super.printStackTrace(s); } catch (Throwable e) { } Throwable exception = getException(); for (int i = 0; (i < 10) && (null != exception); i++) { s.println("---------"); try { exception.printStackTrace(s); // if exception is a TransformerException it will print // its contained exception, so we don't need to redo it here, // and we can exit the loop now. if (exception instanceof TransformerException) break; } catch (Throwable e) { s.println("Could not print stack trace..."); } try { // Is this still needed? Method meth = exception.getClass().getMethod("getException"); if (null != meth) { Throwable prev = exception; exception = (Throwable) meth.invoke(exception, (Object[]) null); if (prev == exception) { break; } } else { exception = null; } } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) { exception = null; } } } finally { // ensure output is written s.flush(); } } /** * Creates a ProtectionDomain that has no permission. * @return a ProtectionDomain */ private ProtectionDomain getNonPrivDomain() { CodeSource nullSource = new CodeSource(null, (CodeSigner[]) null); PermissionCollection noPermission = new Permissions(); return new ProtectionDomain(nullSource, noPermission); } }