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Diffstat (limited to 'java/lang/StackTraceElement.java')
| -rw-r--r-- | java/lang/StackTraceElement.java | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/java/lang/StackTraceElement.java b/java/lang/StackTraceElement.java new file mode 100644 index 000000000..9c60ab164 --- /dev/null +++ b/java/lang/StackTraceElement.java @@ -0,0 +1,259 @@ +/* StackTraceElement.java -- One function call or call stack element + Copyright (C) 2001, 2002 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.lang; + +import java.io.Serializable; + +/** + * One function call or stack trace element. Gives information about + * the execution point such as the source file name, the line number, + * the fully qualified class name, the method name and whether this method + * is native, if this information is known. + * + * @author Mark Wielaard <mark@klomp.org> + * @author Eric Blake <ebb9@email.byu.edu> + * @since 1.4 + * @status updated to 1.4 + */ +public class StackTraceElement implements Serializable +{ + /** + * Compatible with JDK 1.4+. + */ + private static final long serialVersionUID = 6992337162326171013L; + + /** + * The name of the file, null if unknown. + * + * @serial the source code filename, if known + */ + private final String fileName; + + /** + * The line number in the file, negative if unknown. + * + * @serial the source code line number, if known + */ + private final int lineNumber; + + /** + * The fully qualified class name, null if unknown. + * + * @serial the enclosing class, if known + */ + private final String className; + + /** + * The method name in the class, null if unknown. + * + * @serial the enclosing method, if known + */ + private final String methodName; + + /** Whether the method is native. */ + private final transient boolean isNative; + + /** + * A package local constructor for the StackTraceElement class, to be + * called by the Virtual Machine as part of Throwable.fillInStackTrace. + * There are no public constructors defined for this class. Creation + * of new elements is implementation specific. + * + * @param fileName the name of the file, null if unknown + * @param lineNumber the line in the file, negative if unknown + * @param className the fully qualified name of the class, null if unknown + * @param methodName the name of the method, null if unknown + * @param isNative true if native, false otherwise + */ + StackTraceElement(String fileName, int lineNumber, String className, + String methodName, boolean isNative) + { + this.fileName = fileName; + this.lineNumber = lineNumber; + this.className = className; + this.methodName = methodName; + this.isNative = isNative; + } + + /** + * Returns the name of the file, or null if unknown. This is usually + * obtained from the <code>SourceFile</code> attribute of the class file + * format, if present. + * + * @return the file name + */ + public String getFileName() + { + return fileName; + } + + /** + * Returns the line number in the file, or a negative number if unknown. + * This is usually obtained from the <code>LineNumberTable</code> attribute + * of the method in the class file format, if present. + * + * @return the line number + */ + public int getLineNumber() + { + return lineNumber; + } + + /** + * Returns the fully qualified class name, or null if unknown. + * + * @return the class name + */ + public String getClassName() + { + return className; + } + + /** + * Returns the method name in the class, or null if unknown. If the + * execution point is in a constructor, the name is + * <code><init></code>; if the execution point is in the class + * initializer, the name is <code><clinit></code>. + * + * @return the method name + */ + public String getMethodName() + { + return methodName; + } + + /** + * Returns true if the method is native, or false if it is not or unknown. + * + * @return whether the method is native + */ + public boolean isNativeMethod() + { + return isNative; + } + + /** + * Returns a string representation of this stack trace element. The + * returned String is implementation specific. This implementation + * returns the following String: "[class][.][method]([file][:line])". + * If the fully qualified class name or the method is unknown it is + * omitted including the point seperator. If the source file name is + * unknown it is replaced by "Unknown Source" if the method is not native + * or by "Native Method" if the method is native. If the line number + * is unknown it and the colon are omitted. + * + * @return a string representation of this execution point + */ + public String toString() + { + StringBuffer sb = new StringBuffer(); + if (className != null) + { + sb.append(className); + if (methodName != null) + sb.append('.'); + } + if (methodName != null) + sb.append(methodName); + sb.append('('); + if (fileName != null) + sb.append(fileName); + else + sb.append(isNative ? "Native Method" : "Unknown Source"); + if (lineNumber >= 0) + sb.append(':').append(lineNumber); + sb.append(')'); + return sb.toString(); + } + + /** + * Returns true if the given object is also a StackTraceElement and all + * attributes, except the native flag, are equal (either the same attribute + * between the two elments are null, or both satisfy Object.equals). + * + * @param o the object to compare + * @return true if the two are equal + */ + public boolean equals(Object o) + { + if (! (o instanceof StackTraceElement)) + return false; + StackTraceElement e = (StackTraceElement) o; + return equals(fileName, e.fileName) + && lineNumber == e.lineNumber + && equals(className, e.className) + && equals(methodName, e.methodName); + } + + /** + * Returns the hashCode of this StackTraceElement. This implementation + * computes the hashcode by xor-ing the hashcode of all attributes except + * the native flag. + * + * @return the hashcode + */ + public int hashCode() + { + return hashCode(fileName) ^ lineNumber ^ hashCode(className) + ^ hashCode(methodName); + } + + /** + * Compare two objects according to Collection semantics. + * + * @param o1 the first object + * @param o2 the second object + * @return o1 == null ? o2 == null : o1.equals(o2) + */ + private static final boolean equals(Object o1, Object o2) + { + return o1 == null ? o2 == null : o1.equals(o2); + } + + /** + * Hash an object according to Collection semantics. + * + * @param o the object to hash + * @return o1 == null ? 0 : o1.hashCode() + */ + private static final int hashCode(Object o) + { + return o == null ? 0 : o.hashCode(); + } +} |