java.lang
Class StackTraceElement

java.lang.Object
  extended byjava.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 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
See Also:
Serialized Form

Field Summary
private  String declaringClass
           
private  String fileName
           
private  int lineNumber
           
private  String methodName
           
private static long serialVersionUID
           
 
Constructor Summary
private StackTraceElement()
          Prevent inappropriate instantiation.
 
Method Summary
private static boolean eq(Object a, Object b)
           
 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
 

Field Detail

declaringClass

private String declaringClass

methodName

private String methodName

fileName

private String fileName

lineNumber

private int lineNumber

serialVersionUID

private static final long serialVersionUID
See Also:
Constant Field Values
Constructor Detail

StackTraceElement

private StackTraceElement()
Prevent inappropriate instantiation. Only the VM creates these. It creates them "magically" without invoking this constructor.

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

eq

private static boolean eq(Object a,
                          Object b)

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