| /* |
| * Copyright (c) 2000, 2004, 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 java.lang; |
| |
| /** |
| * An element in a stack trace, as returned by {@link |
| * Throwable#getStackTrace()}. Each element represents a single stack frame. |
| * All stack frames except for the one at the top of the stack represent |
| * a method invocation. The frame at the top of the stack represents the |
| * execution point at which the stack trace was generated. Typically, |
| * this is the point at which the throwable corresponding to the stack trace |
| * was created. |
| * |
| * @since 1.4 |
| * @author Josh Bloch |
| */ |
| public final class StackTraceElement implements java.io.Serializable { |
| // Normally initialized by VM (public constructor added in 1.5) |
| private String declaringClass; |
| private String methodName; |
| private String fileName; |
| private int lineNumber; |
| |
| /** |
| * Creates a stack trace element representing the specified execution |
| * point. |
| * |
| * @param declaringClass the fully qualified name of the class containing |
| * the execution point represented by the stack trace element |
| * @param methodName the name of the method containing the execution point |
| * represented by the stack trace element |
| * @param fileName the name of the file containing the execution point |
| * represented by the stack trace element, or <tt>null</tt> if |
| * this information is unavailable |
| * @param lineNumber the line number of the source line containing the |
| * execution point represented by this stack trace element, or |
| * a negative number if this information is unavailable. A value |
| * of -2 indicates that the method containing the execution point |
| * is a native method |
| * @throws NullPointerException if <tt>declaringClass</tt> or |
| * <tt>methodName</tt> is null |
| * @since 1.5 |
| */ |
| public StackTraceElement(String declaringClass, String methodName, |
| String fileName, int lineNumber) { |
| if (declaringClass == null) |
| throw new NullPointerException("Declaring class is null"); |
| if (methodName == null) |
| throw new NullPointerException("Method name is null"); |
| |
| this.declaringClass = declaringClass; |
| this.methodName = methodName; |
| this.fileName = fileName; |
| this.lineNumber = lineNumber; |
| } |
| |
| /** |
| * Returns the name of the source file containing the execution point |
| * represented by this stack trace element. Generally, this corresponds |
| * to the <tt>SourceFile</tt> attribute of the relevant <tt>class</tt> |
| * file (as per <i>The Java Virtual Machine Specification</i>, Section |
| * 4.7.7). In some systems, the name may refer to some source code unit |
| * other than a file, such as an entry in source repository. |
| * |
| * @return the name of the file containing the execution point |
| * represented by this stack trace element, or <tt>null</tt> if |
| * this information is unavailable. |
| */ |
| public String getFileName() { |
| return fileName; |
| } |
| |
| /** |
| * Returns the line number of the source line containing the execution |
| * point represented by this stack trace element. Generally, this is |
| * derived from the <tt>LineNumberTable</tt> attribute of the relevant |
| * <tt>class</tt> file (as per <i>The Java Virtual Machine |
| * Specification</i>, Section 4.7.8). |
| * |
| * @return the line number of the source line containing the execution |
| * point represented by this stack trace element, or a negative |
| * number if this information is unavailable. |
| */ |
| public int getLineNumber() { |
| return lineNumber; |
| } |
| |
| /** |
| * Returns the fully qualified name of the class containing the |
| * execution point represented by this stack trace element. |
| * |
| * @return the fully qualified name of the <tt>Class</tt> containing |
| * the execution point represented by this stack trace element. |
| */ |
| public String getClassName() { |
| return declaringClass; |
| } |
| |
| /** |
| * Returns the name of the method containing the execution point |
| * represented by this stack trace element. If the execution point is |
| * contained in an instance or class initializer, this method will return |
| * the appropriate <i>special method name</i>, <tt><init></tt> or |
| * <tt><clinit></tt>, as per Section 3.9 of <i>The Java Virtual |
| * Machine Specification</i>. |
| * |
| * @return the name of the method containing the execution point |
| * represented by this stack trace element. |
| */ |
| public String getMethodName() { |
| return methodName; |
| } |
| |
| /** |
| * Returns true if the method containing the execution point |
| * represented by this stack trace element is a native method. |
| * |
| * @return <tt>true</tt> if the method containing the execution point |
| * represented by this stack trace element is a native method. |
| */ |
| public boolean isNativeMethod() { |
| return lineNumber == -2; |
| } |
| |
| /** |
| * Returns a string representation of this stack trace element. The |
| * format of this string depends on the implementation, but the following |
| * examples may be regarded as typical: |
| * <ul> |
| * <li> |
| * <tt>"MyClass.mash(MyClass.java:9)"</tt> - Here, <tt>"MyClass"</tt> |
| * is the <i>fully-qualified name</i> of the class containing the |
| * execution point represented by this stack trace element, |
| * <tt>"mash"</tt> is the name of the method containing the execution |
| * point, <tt>"MyClass.java"</tt> is the source file containing the |
| * execution point, and <tt>"9"</tt> is the line number of the source |
| * line containing the execution point. |
| * <li> |
| * <tt>"MyClass.mash(MyClass.java)"</tt> - As above, but the line |
| * number is unavailable. |
| * <li> |
| * <tt>"MyClass.mash(Unknown Source)"</tt> - As above, but neither |
| * the file name nor the line number are available. |
| * <li> |
| * <tt>"MyClass.mash(Native Method)"</tt> - As above, but neither |
| * the file name nor the line number are available, and the method |
| * containing the execution point is known to be a native method. |
| * </ul> |
| * @see Throwable#printStackTrace() |
| */ |
| public String toString() { |
| return getClassName() + "." + methodName + |
| (isNativeMethod() ? "(Native Method)" : |
| (fileName != null && lineNumber >= 0 ? |
| "(" + fileName + ":" + lineNumber + ")" : |
| (fileName != null ? "("+fileName+")" : "(Unknown Source)"))); |
| } |
| |
| /** |
| * Returns true if the specified object is another |
| * <tt>StackTraceElement</tt> instance representing the same execution |
| * point as this instance. Two stack trace elements <tt>a</tt> and |
| * <tt>b</tt> are equal if and only if: |
| * <pre> |
| * equals(a.getFileName(), b.getFileName()) && |
| * a.getLineNumber() == b.getLineNumber()) && |
| * equals(a.getClassName(), b.getClassName()) && |
| * equals(a.getMethodName(), b.getMethodName()) |
| * </pre> |
| * where <tt>equals</tt> is defined as: |
| * <pre> |
| * static boolean equals(Object a, Object b) { |
| * return a==b || (a != null && a.equals(b)); |
| * } |
| * </pre> |
| * |
| * @param obj the object to be compared with this stack trace element. |
| * @return true if the specified object is another |
| * <tt>StackTraceElement</tt> instance representing the same |
| * execution point as this instance. |
| */ |
| public boolean equals(Object obj) { |
| if (obj==this) |
| return true; |
| if (!(obj instanceof StackTraceElement)) |
| return false; |
| StackTraceElement e = (StackTraceElement)obj; |
| return e.declaringClass.equals(declaringClass) && e.lineNumber == lineNumber |
| && eq(methodName, e.methodName) && eq(fileName, e.fileName); |
| } |
| |
| private static boolean eq(Object a, Object b) { |
| return a==b || (a != null && a.equals(b)); |
| } |
| |
| /** |
| * Returns a hash code value for this stack trace element. |
| */ |
| public int hashCode() { |
| int result = 31*declaringClass.hashCode() + methodName.hashCode(); |
| result = 31*result + (fileName == null ? 0 : fileName.hashCode()); |
| result = 31*result + lineNumber; |
| return result; |
| } |
| |
| private static final long serialVersionUID = 6992337162326171013L; |
| } |
