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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (c) 2000, 2013, 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;
import java.util.Objects;
/**
* 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 {@code null} 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 {@code declaringClass} or
* {@code methodName} is null
* @since 1.5
*/
public StackTraceElement(String declaringClass, String methodName,
String fileName, int lineNumber) {
this.declaringClass = Objects.requireNonNull(declaringClass, "Declaring class is null");
this.methodName = Objects.requireNonNull(methodName, "Method name is null");
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 {@code SourceFile} attribute of the relevant {@code class}
* file (as per The Java Virtual Machine Specification, 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 {@code null} 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 {@code LineNumberTable} attribute of the relevant
* {@code class} file (as per The Java Virtual Machine
* Specification, 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 {@code Class} 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 special method name, {@code } or
* {@code }, as per Section 3.9 of The Java Virtual
* Machine Specification.
*
* @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 {@code true} 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:
*
* -
* {@code "MyClass.mash(MyClass.java:9)"} - Here, {@code "MyClass"}
* is the fully-qualified name of the class containing the
* execution point represented by this stack trace element,
* {@code "mash"} is the name of the method containing the execution
* point, {@code "MyClass.java"} is the source file containing the
* execution point, and {@code "9"} is the line number of the source
* line containing the execution point.
*
-
* {@code "MyClass.mash(MyClass.java)"} - As above, but the line
* number is unavailable.
*
-
* {@code "MyClass.mash(Unknown Source)"} - As above, but neither
* the file name nor the line number are available.
*
-
* {@code "MyClass.mash(Native Method)"} - 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.
*
* @see Throwable#printStackTrace()
*/
public String toString() {
// BEGIN Android-changed: Fall back Unknown Source: for unknown lineNumber.
// http://b/30183883
// The only behavior change is that "Unknown Source" is followed by a number
// (the value of the dex program counter, dex_pc), which never occurs on the
// RI. This value isn't a line number, but can be useful for debugging and
// avoids the need to ship line number information along with the dex code to
// get an accurate stack trace.
// Formatting it in this way might be more digestible to automated tools that
// are not specifically written to expect this behavior.
/*
return getClassName() + "." + methodName +
(isNativeMethod() ? "(Native Method)" :
(fileName != null && lineNumber >= 0 ?
"(" + fileName + ":" + lineNumber + ")" :
(fileName != null ? "("+fileName+")" : "(Unknown Source)")));
*/
StringBuilder result = new StringBuilder();
result.append(getClassName()).append(".").append(methodName);
if (isNativeMethod()) {
result.append("(Native Method)");
} else if (fileName != null) {
if (lineNumber >= 0) {
result.append("(").append(fileName).append(":").append(lineNumber).append(")");
} else {
result.append("(").append(fileName).append(")");
}
} else {
if (lineNumber >= 0) {
// The line number is actually the dex pc.
result.append("(Unknown Source:").append(lineNumber).append(")");
} else {
result.append("(Unknown Source)");
}
}
return result.toString();
// END Android-changed: Fall back Unknown Source: for unknown lineNumber.
}
/**
* Returns true if the specified object is another
* {@code StackTraceElement} instance representing the same execution
* point as this instance. Two stack trace elements {@code a} and
* {@code b} are equal if and only if:
* {@code
* equals(a.getFileName(), b.getFileName()) &&
* a.getLineNumber() == b.getLineNumber()) &&
* equals(a.getClassName(), b.getClassName()) &&
* equals(a.getMethodName(), b.getMethodName())
* }
* where {@code equals} has the semantics of {@link
* java.util.Objects#equals(Object, Object) Objects.equals}.
*
* @param obj the object to be compared with this stack trace element.
* @return true if the specified object is another
* {@code StackTraceElement} 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 &&
Objects.equals(methodName, e.methodName) &&
Objects.equals(fileName, e.fileName);
}
/**
* Returns a hash code value for this stack trace element.
*/
public int hashCode() {
int result = 31*declaringClass.hashCode() + methodName.hashCode();
result = 31*result + Objects.hashCode(fileName);
result = 31*result + lineNumber;
return result;
}
private static final long serialVersionUID = 6992337162326171013L;
}