Module java.base
Package java.lang

Class 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

      All Methods Instance Methods Concrete Methods 
      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 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.
      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.

    • Constructor Detail

      • 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 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

      • 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 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 is null or methodName is null
        Since:
        9

    • 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.

      • 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 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.
        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/[email protected]/com.foo.Main.run(Main.java:101)" - See the description below.
        • "com.foo.loader/[email protected]/com.foo.Main.run(Main.java)" - The line number is unavailable.
        • "com.foo.loader/[email protected]/com.foo.Main.run(Unknown Source)" - Neither the file name nor the line number is available.
        • "com.foo.loader/[email protected]/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.
        • "[email protected]/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 with 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 "[email protected]" is the module name and version. The third element is the method containing the execution point; "com.foo.Main"" is the fully-qualified class 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 "[email protected]/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