Class StackWalker

java.lang.Object

java.lang.StackWalker

public final class StackWalker
extends Object

This provides a facility for iterating over the call stack of the current thread. A StackWalker object may be used multiple times by different threads, but it will represent the state of the current thread at the time the stack is walked. A StackWalker may be provided with one or more Option settings to include information and stack frames such as reflection methods, hidden frames, and Class objects.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	StackWalker.Option	Selects what type of stack and method information is provided by the StackWalker.
static interface	StackWalker.StackFrame	Contains information about the StackWalker's current stack frame.

Method Summary

Modifier and Type	Method	Description
void	forEach(Consumer<? super StackWalker.StackFrame> action)
Class<?>	getCallerClass()	Get the caller of the caller of this function, eliding any reflection or hidden frames.
static StackWalker	getInstance()	Factory method to create a StackWalker instance with no options set.
static StackWalker	getInstance(StackWalker.Option option)	Factory method to create a StackWalker with one option.
static StackWalker	getInstance(Set<StackWalker.Option> options)	Factory method to create a StackWalker with any number of options.
static StackWalker	getInstance(Set<StackWalker.Option> options, int estimatedDepth)	Factory method to create a StackWalker.
<T> T	walk(Function<? super Stream<StackWalker.StackFrame>, ? extends T> function)	Traverse the calling thread's stack at the time this method is called and apply function to each stack frame.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Method Details

getInstance

public static StackWalker getInstance()

Factory method to create a StackWalker instance with no options set.

Returns:

StackWalker StackWalker object

getInstance

public static StackWalker getInstance(StackWalker.Option option)

Factory method to create a StackWalker with one option. This is provided for the case where only a single option is required.

Parameters:

option - select the type of information to include

Returns:

StackWalker instance configured with the value of option

getInstance

public static StackWalker getInstance(Set<StackWalker.Option> options)

Factory method to create a StackWalker with any number of options.

Parameters:

options - select the types of information to include

Returns:

StackWalker instance configured with the given options

getInstance

public static StackWalker getInstance(Set<StackWalker.Option> options,
 int estimatedDepth)

Factory method to create a StackWalker.

Parameters:

options - select the types of information to include

estimatedDepth - hint for the size of buffer to use. Must be 1 or greater

Returns:

StackWalker instance with the given options specifying the stack frame information it can access

forEach

public void forEach(Consumer<? super StackWalker.StackFrame> action)

Parameters:

action - Consumer object Iterate over the stack from top to bottom and apply the Consumer to each StackWalker.StackFrame

getCallerClass

public Class<?> getCallerClass()

Get the caller of the caller of this function, eliding any reflection or hidden frames.

Returns:

Class object for the method calling the current method.

Throws:

UnsupportedOperationException - if the StackWalker was not created with StackWalker.Option.RETAIN_CLASS_REFERENCE

IllegalStateException - if the caller is at the bottom of the stack

walk

public <T> T walk(Function<? super Stream<StackWalker.StackFrame>, ? extends T> function)

Traverse the calling thread's stack at the time this method is called and apply function to each stack frame.

Type Parameters:

T - the type of the return value from applying function to the stream

Parameters:

function - operation to apply to the stream

Returns:

the value returned by function