Module java.base

Package java.lang

Class StackTraceElement

java.lang.Object

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

Constructors

Constructor	Description
StackTraceElement(String declaringClass, String methodName, String fileName, int lineNumber)	Creates a stack trace element representing the specified execution point.
StackTraceElement(String classLoaderName, String moduleName, String moduleVersion, String declaringClass, String methodName, String fileName, int lineNumber)	Creates a stack trace element representing the specified execution point.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)	Returns true if the specified object is another StackTraceElement instance representing the same execution point as this instance.
String	getClassLoaderName()	Returns the name of the class loader of the class containing the execution point represented by this stack trace element.
String	getClassName()	Returns the binary 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.
String	getModuleName()	Returns the module name of the module containing the execution point represented by this stack trace element.
String	getModuleVersion()	Returns the module version of the module 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 declared in class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

StackTraceElement

public StackTraceElement(String declaringClass,
 String methodName,
 String fileName,
 int lineNumber)

Creates a stack trace element representing the specified execution point. The module name and module version of the stack trace element will be null.

Parameters:

declaringClass - the binary 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

StackTraceElement

public StackTraceElement(String classLoaderName,
 String moduleName,
 String moduleVersion,
 String declaringClass,
 String methodName,
 String fileName,
 int lineNumber)

Creates a stack trace element representing the specified execution point.

Parameters:

classLoaderName - the class loader name if the class loader of the class containing the execution point represented by the stack trace is named; otherwise null

moduleName - the module name if the class containing the execution point represented by the stack trace is in a named module; otherwise null

moduleVersion - the module version if the class containing the execution point represented by the stack trace is in a named module that has a version; otherwise null

declaringClass - the binary 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 is null or methodName is null

Since:

9

Method Details

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.

getModuleName

public String getModuleName()

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

Returns:

the module name of the Module containing the execution point represented by this stack trace element; null if the module name is not available.

Since:

9

See Also:

• Module.getName()

getModuleVersion

public String getModuleVersion()

Returns the module version of the module containing the execution point represented by this stack trace element.

Returns:

the module version of the Module containing the execution point represented by this stack trace element; null if the module version is not available.

Since:

9

See Also:

• ModuleDescriptor.Version

getClassLoaderName

public String getClassLoaderName()

Returns the name of the class loader of the class containing the execution point represented by this stack trace element.

Returns:

the name of the class loader of the class containing the execution point represented by this stack trace element; null if the class loader is not named.

Since:

9

See Also:

• ClassLoader.getName()

getClassName

public String getClassName()

Returns the binary name of the Class containing the execution point represented by this stack trace element.

Returns:

the binary 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.

Overrides:

toString in class Object

API Note:

The format of this string depends on the implementation, but the following examples may be regarded as typical:

• "com.foo.loader/foo@9.0/com.foo.Main.run(Main.java:101)" - See the description below.
• "com.foo.loader/foo@9.0/com.foo.Main.run(Main.java)" - The line number is unavailable.
• "com.foo.loader/foo@9.0/com.foo.Main.run(Unknown Source)" - Neither the file name nor the line number is available.
• "com.foo.loader/foo@9.0/com.foo.Main.run(Native Method)" - The method containing the execution point is a native method.
• "com.foo.loader//com.foo.bar.App.run(App.java:12)" - The class of the execution point is defined in the unnamed module of the class loader named com.foo.loader.
• "acme@2.1/org.acme.Lib.test(Lib.java:80)" - The class of the execution point is defined in acme module loaded by a built-in class loader such as the application class loader.
• "MyClass.mash(MyClass.java:9)" - MyClass class is on the application class path.

The first example shows a stack trace element consisting of three elements, each separated by "/", followed by the source file name and the line number of the source line containing the execution point. The first element "com.foo.loader" is the name of the class loader. The second element "foo@9.0" is the module name and version. The third element is the method containing the execution point; "com.foo.Main"" is the binary name and "run" is the name of the method. "Main.java" is the source file name and "101" is the line number.

If a class is defined in an unnamed module then the second element is omitted as shown in "com.foo.loader//com.foo.bar.App.run(App.java:12)".

If the class loader is a built-in class loader or is not named then the first element and its following "/" are omitted as shown in "acme@2.1/org.acme.Lib.test(Lib.java:80)". If the first element is omitted and the module is an unnamed module, the second element and its following "/" are also omitted as shown in "MyClass.mash(MyClass.java:9)".

The toString method may return two different values on two StackTraceElement instances that are equal, for example one created via the constructor, and one obtained from Throwable or StackWalker.StackFrame, where an implementation may choose to omit some element in the returned string.

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.getClassLoaderName(), b.getClassLoaderName()) &&
     equals(a.getModuleName(), b.getModuleName()) &&
     equals(a.getModuleVersion(), b.getModuleVersion()) &&
     equals(a.getClassName(), b.getClassName()) &&
     equals(a.getMethodName(), b.getMethodName())
     equals(a.getFileName(), b.getFileName()) &&
     a.getLineNumber() == b.getLineNumber()

 

where equals has the semantics of Objects.equals.

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()
• HashMap

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)
• System.identityHashCode(java.lang.Object)