JavaTM 2 Platform
Standard Ed. 5.0

java.lang
Class StackTraceElement

java.lang.Object
  extended by java.lang.StackTraceElement
All Implemented Interfaces:
Serializable

public final class StackTraceElement
extends Object
implements Serializable

An element in a stack trace, as returned by 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
See Also:
Serialized Form

Constructor Summary
StackTraceElement(String declaringClass, String methodName, String fileName, int lineNumber)
          Creates a stack trace element representing the specified execution point.
 
Method Summary
 boolean equals(Object obj)
          Returns true if the specified object is another StackTraceElement instance representing the same execution point as this instance.
 String getClassName()
          Returns the fully qualified name of the class containing the execution point represented by this stack trace element.
 String getFileName()
          Returns the name of the source file containing the execution point represented by this stack trace element.
 int getLineNumber()
          Returns the line number of the source line containing the execution point represented by this stack trace element.
 String getMethodName()
          Returns the name of the method containing the execution point represented by this stack trace element.
 int hashCode()
          Returns a hash code value for this stack trace element.
 boolean isNativeMethod()
          Returns true if the method containing the execution point represented by this stack trace element is a native method.
 String toString()
          Returns a string representation of this stack trace element.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

StackTraceElement

public StackTraceElement(String declaringClass,
                         String methodName,
                         String fileName,
                         int lineNumber)
Creates a stack trace element representing the specified execution point.

Parameters:
declaringClass - the fully qualified name of the class containing the execution point represented by the stack trace element
methodName - the name of the method containing the execution point represented by the stack trace element
fileName - the name of the file containing the execution point represented by the stack trace element, or null if this information is unavailable
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 declaringClass or methodName is null
Since:
1.5
Method Detail

getFileName

public String getFileName()
Returns the name of the source file containing the execution point represented by this stack trace element. Generally, this corresponds to the SourceFile attribute of the relevant 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.

Returns:
the name of the file containing the execution point represented by this stack trace element, or null if this information is unavailable.

getLineNumber

public int getLineNumber()
Returns the line number of the source line containing the execution point represented by this stack trace element. Generally, this is derived from the LineNumberTable attribute of the relevant class file (as per The Java Virtual Machine Specification, Section 4.7.8).

Returns:
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.

getClassName

public String getClassName()
Returns the fully qualified name of the class containing the execution point represented by this stack trace element.

Returns:
the fully qualified name of the Class containing the execution point represented by this stack trace element.

getMethodName

public String getMethodName()
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, <init> or <clinit>, as per Section 3.9 of The Java Virtual Machine Specification.

Returns:
the name of the method containing the execution point represented by this stack trace element.

isNativeMethod

public boolean isNativeMethod()
Returns true if the method containing the execution point represented by this stack trace element is a native method.

Returns:
true if the method containing the execution point represented by this stack trace element is a native method.

toString

public String toString()
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:

Overrides:
toString in class Object
Returns:
a string representation of the object.
See Also:
Throwable.printStackTrace()

equals

public boolean equals(Object obj)
Returns true if the specified object is another StackTraceElement instance representing the same execution point as this instance. Two stack trace elements a and b are equal if and only if:
     equals(a.getFileName(), b.getFileName()) &&
     a.getLineNumber() == b.getLineNumber()) &&
     equals(a.getClassName(), b.getClassName()) &&
     equals(a.getMethodName(), b.getMethodName())
 
where equals is defined as:
     static boolean equals(Object a, Object b) {
         return a==b || (a != null && a.equals(b));
     }
 

Overrides:
equals in class Object
Parameters:
obj - the object to be compared with this stack trace element.
Returns:
true if the specified object is another StackTraceElement instance representing the same execution point as this instance.
See Also:
Object.hashCode(), Hashtable

hashCode

public int hashCode()
Returns a hash code value for this stack trace element.

Overrides:
hashCode in class Object
Returns:
a hash code value for this object.
See Also:
Object.equals(java.lang.Object), Hashtable

JavaTM 2 Platform
Standard Ed. 5.0

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2004 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.