Package java.lang

Interface Summary
Appendable sample code for java.lang.Appendable definition code for java.lang.Appendable An object to which char sequences and values can be appended.
CharSequence sample code for java.lang.CharSequence definition code for java.lang.CharSequence A CharSequence is a readable sequence of char values.
Cloneable sample code for java.lang.Cloneable definition code for java.lang.Cloneable A class implements the Cloneable interface to indicate to the Object.clone() sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() method that it is legal for that method to make a field-for-field copy of instances of that class.
Comparable<T> sample code for java.lang.Comparable definition code for java.lang.Comparable This interface imposes a total ordering on the objects of each class that implements it.
Iterable<T> sample code for java.lang.Iterable definition code for java.lang.Iterable Implementing this interface allows an object to be the target of the "foreach" statement.
Readable sample code for java.lang.Readable definition code for java.lang.Readable A Readable is a source of characters.
Runnable sample code for java.lang.Runnable definition code for java.lang.Runnable The Runnable interface should be implemented by any class whose instances are intended to be executed by a thread.
Thread.UncaughtExceptionHandler sample code for java.lang.Thread.UncaughtExceptionHandler definition code for java.lang.Thread.UncaughtExceptionHandler Interface for handlers invoked when a Thread abruptly terminates due to an uncaught exception.

Class Summary
Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean The Boolean class wraps a value of the primitive type boolean in an object.
Byte sample code for java.lang.Byte definition code for java.lang.Byte The Byte class wraps a value of primitive type byte in an object.
Character sample code for java.lang.Character definition code for java.lang.Character The Character class wraps a value of the primitive type char in an object.
Character.Subset sample code for java.lang.Character.Subset definition code for java.lang.Character.Subset Instances of this class represent particular subsets of the Unicode character set.
Character.UnicodeBlock sample code for java.lang.Character.UnicodeBlock definition code for java.lang.Character.UnicodeBlock A family of character subsets representing the character blocks in the Unicode specification.
Class<T> sample code for java.lang.Class definition code for java.lang.Class Instances of the class Class represent classes and interfaces in a running Java application.
ClassLoader sample code for java.lang.ClassLoader definition code for java.lang.ClassLoader A class loader is an object that is responsible for loading classes.
Compiler sample code for java.lang.Compiler definition code for java.lang.Compiler The Compiler class is provided to support Java-to-native-code compilers and related services.
Double sample code for java.lang.Double definition code for java.lang.Double The Double class wraps a value of the primitive type double in an object.
Enum<E extends Enum<E>> sample code for java.lang.Enum definition code for java.lang.Enum This is the common base class of all Java language enumeration types.
Float sample code for java.lang.Float definition code for java.lang.Float The Float class wraps a value of primitive type float in an object.
InheritableThreadLocal<T> sample code for java.lang.InheritableThreadLocal definition code for java.lang.InheritableThreadLocal This class extends ThreadLocal to provide inheritance of values from parent thread to child thread: when a child thread is created, the child receives initial values for all inheritable thread-local variables for which the parent has values.
Integer sample code for java.lang.Integer definition code for java.lang.Integer The Integer class wraps a value of the primitive type int in an object.
Long sample code for java.lang.Long definition code for java.lang.Long The Long class wraps a value of the primitive type long in an object.
Math sample code for java.lang.Math definition code for java.lang.Math The class Math contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.
Number sample code for java.lang.Number definition code for java.lang.Number The abstract class Number is the superclass of classes BigDecimal, BigInteger, Byte, Double, Float, Integer, Long, and Short.
Object sample code for java.lang.Object definition code for java.lang.Object Class Object is the root of the class hierarchy.
Package sample code for java.lang.Package definition code for java.lang.Package Package objects contain version information about the implementation and specification of a Java package.
Process sample code for java.lang.Process definition code for java.lang.Process The ProcessBuilder.start() sample code for java.lang.ProcessBuilder.start() definition code for java.lang.ProcessBuilder.start() and Runtime.exec sample code for java.lang.Runtime.exec(java.lang.String[], java.lang.String[], definition code for java.lang.Runtime.exec(java.lang.String[], java.lang.String[], methods create a native process and return an instance of a subclass of Process that can be used to control the process and obtain information about it.
ProcessBuilder sample code for java.lang.ProcessBuilder definition code for java.lang.ProcessBuilder This class is used to create operating system processes.
Runtime sample code for java.lang.Runtime definition code for java.lang.Runtime Every Java application has a single instance of class Runtime that allows the application to interface with the environment in which the application is running.
RuntimePermission sample code for java.lang.RuntimePermission definition code for java.lang.RuntimePermission This class is for runtime permissions.
SecurityManager sample code for java.lang.SecurityManager definition code for java.lang.SecurityManager The security manager is a class that allows applications to implement a security policy.
Short sample code for java.lang.Short definition code for java.lang.Short The Short class wraps a value of primitive type short in an object.
StackTraceElement sample code for java.lang.StackTraceElement definition code for java.lang.StackTraceElement An element in a stack trace, as returned by Throwable.getStackTrace() sample code for java.lang.Throwable.getStackTrace() definition code for java.lang.Throwable.getStackTrace() .
StrictMath sample code for java.lang.StrictMath definition code for java.lang.StrictMath The class StrictMath contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.
String sample code for java.lang.String definition code for java.lang.String The String class represents character strings.
StringBuffer sample code for java.lang.StringBuffer definition code for java.lang.StringBuffer A thread-safe, mutable sequence of characters.
StringBuilder sample code for java.lang.StringBuilder definition code for java.lang.StringBuilder A mutable sequence of characters.
System sample code for java.lang.System definition code for java.lang.System The System class contains several useful class fields and methods.
Thread sample code for java.lang.Thread definition code for java.lang.Thread A thread is a thread of execution in a program.
ThreadGroup sample code for java.lang.ThreadGroup definition code for java.lang.ThreadGroup A thread group represents a set of threads.
ThreadLocal<T> sample code for java.lang.ThreadLocal definition code for java.lang.ThreadLocal This class provides thread-local variables.
Throwable sample code for java.lang.Throwable definition code for java.lang.Throwable The Throwable class is the superclass of all errors and exceptions in the Java language.
Void sample code for java.lang.Void definition code for java.lang.Void The Void class is an uninstantiable placeholder class to hold a reference to the Class object representing the Java keyword void.

Enum Summary
Thread.State sample code for java.lang.Thread.State definition code for java.lang.Thread.State A thread state.

Exception Summary
ArithmeticException sample code for java.lang.ArithmeticException definition code for java.lang.ArithmeticException Thrown when an exceptional arithmetic condition has occurred.
ArrayIndexOutOfBoundsException sample code for java.lang.ArrayIndexOutOfBoundsException definition code for java.lang.ArrayIndexOutOfBoundsException Thrown to indicate that an array has been accessed with an illegal index.
ArrayStoreException sample code for java.lang.ArrayStoreException definition code for java.lang.ArrayStoreException Thrown to indicate that an attempt has been made to store the wrong type of object into an array of objects.
ClassCastException sample code for java.lang.ClassCastException definition code for java.lang.ClassCastException Thrown to indicate that the code has attempted to cast an object to a subclass of which it is not an instance.
ClassNotFoundException sample code for java.lang.ClassNotFoundException definition code for java.lang.ClassNotFoundException Thrown when an application tries to load in a class through its string name using: The forName method in class Class.
CloneNotSupportedException sample code for java.lang.CloneNotSupportedException definition code for java.lang.CloneNotSupportedException Thrown to indicate that the clone method in class Object has been called to clone an object, but that the object's class does not implement the Cloneable interface.
EnumConstantNotPresentException sample code for java.lang.EnumConstantNotPresentException definition code for java.lang.EnumConstantNotPresentException Thrown when an application tries to access an enum constant by name and the enum type contains no constant with the specified name.
Exception sample code for java.lang.Exception definition code for java.lang.Exception The class Exception and its subclasses are a form of Throwable that indicates conditions that a reasonable application might want to catch.
IllegalAccessException sample code for java.lang.IllegalAccessException definition code for java.lang.IllegalAccessException An IllegalAccessException is thrown when an application tries to reflectively create an instance (other than an array), set or get a field, or invoke a method, but the currently executing method does not have access to the definition of the specified class, field, method or constructor.
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException Thrown to indicate that a method has been passed an illegal or inappropriate argument.
IllegalMonitorStateException sample code for java.lang.IllegalMonitorStateException definition code for java.lang.IllegalMonitorStateException Thrown to indicate that a thread has attempted to wait on an object's monitor or to notify other threads waiting on an object's monitor without owning the specified monitor.
IllegalStateException sample code for java.lang.IllegalStateException definition code for java.lang.IllegalStateException Signals that a method has been invoked at an illegal or inappropriate time.
IllegalThreadStateException sample code for java.lang.IllegalThreadStateException definition code for java.lang.IllegalThreadStateException Thrown to indicate that a thread is not in an appropriate state for the requested operation.
IndexOutOfBoundsException sample code for java.lang.IndexOutOfBoundsException definition code for java.lang.IndexOutOfBoundsException Thrown to indicate that an index of some sort (such as to an array, to a string, or to a vector) is out of range.
InstantiationException sample code for java.lang.InstantiationException definition code for java.lang.InstantiationException Thrown when an application tries to create an instance of a class using the newInstance method in class Class, but the specified class object cannot be instantiated because it is an interface or is an abstract class.
InterruptedException sample code for java.lang.InterruptedException definition code for java.lang.InterruptedException Thrown when a thread is waiting, sleeping, or otherwise paused for a long time and another thread interrupts it using the interrupt method in class Thread.
NegativeArraySizeException sample code for java.lang.NegativeArraySizeException definition code for java.lang.NegativeArraySizeException Thrown if an application tries to create an array with negative size.
NoSuchFieldException sample code for java.lang.NoSuchFieldException definition code for java.lang.NoSuchFieldException Signals that the class doesn't have a field of a specified name.
NoSuchMethodException sample code for java.lang.NoSuchMethodException definition code for java.lang.NoSuchMethodException Thrown when a particular method cannot be found.
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException Thrown when an application attempts to use null in a case where an object is required.
NumberFormatException sample code for java.lang.NumberFormatException definition code for java.lang.NumberFormatException Thrown to indicate that the application has attempted to convert a string to one of the numeric types, but that the string does not have the appropriate format.
RuntimeException sample code for java.lang.RuntimeException definition code for java.lang.RuntimeException RuntimeException is the superclass of those exceptions that can be thrown during the normal operation of the Java Virtual Machine.
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException Thrown by the security manager to indicate a security violation.
StringIndexOutOfBoundsException sample code for java.lang.StringIndexOutOfBoundsException definition code for java.lang.StringIndexOutOfBoundsException Thrown by String methods to indicate that an index is either negative or greater than the size of the string.
TypeNotPresentException sample code for java.lang.TypeNotPresentException definition code for java.lang.TypeNotPresentException Thrown when an application tries to access a type using a string representing the type's name, but no definition for the type with the specified name can be found.
UnsupportedOperationException sample code for java.lang.UnsupportedOperationException definition code for java.lang.UnsupportedOperationException Thrown to indicate that the requested operation is not supported.

Error Summary
AbstractMethodError sample code for java.lang.AbstractMethodError definition code for java.lang.AbstractMethodError Thrown when an application tries to call an abstract method.
AssertionError sample code for java.lang.AssertionError definition code for java.lang.AssertionError Thrown to indicate that an assertion has failed.
ClassCircularityError sample code for java.lang.ClassCircularityError definition code for java.lang.ClassCircularityError Thrown when a circularity has been detected while initializing a class.
ClassFormatError sample code for java.lang.ClassFormatError definition code for java.lang.ClassFormatError Thrown when the Java Virtual Machine attempts to read a class file and determines that the file is malformed or otherwise cannot be interpreted as a class file.
Error sample code for java.lang.Error definition code for java.lang.Error An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch.
ExceptionInInitializerError sample code for java.lang.ExceptionInInitializerError definition code for java.lang.ExceptionInInitializerError Signals that an unexpected exception has occurred in a static initializer.
IllegalAccessError sample code for java.lang.IllegalAccessError definition code for java.lang.IllegalAccessError Thrown if an application attempts to access or modify a field, or to call a method that it does not have access to.
IncompatibleClassChangeError sample code for java.lang.IncompatibleClassChangeError definition code for java.lang.IncompatibleClassChangeError Thrown when an incompatible class change has occurred to some class definition.
InstantiationError sample code for java.lang.InstantiationError definition code for java.lang.InstantiationError Thrown when an application tries to use the Java new construct to instantiate an abstract class or an interface.
InternalError sample code for java.lang.InternalError definition code for java.lang.InternalError Thrown to indicate some unexpected internal error has occurred in the Java Virtual Machine.
LinkageError sample code for java.lang.LinkageError definition code for java.lang.LinkageError Subclasses of LinkageError indicate that a class has some dependency on another class; however, the latter class has incompatibly changed after the compilation of the former class.
NoClassDefFoundError sample code for java.lang.NoClassDefFoundError definition code for java.lang.NoClassDefFoundError Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found.
NoSuchFieldError sample code for java.lang.NoSuchFieldError definition code for java.lang.NoSuchFieldError Thrown if an application tries to access or modify a specified field of an object, and that object no longer has that field.
NoSuchMethodError sample code for java.lang.NoSuchMethodError definition code for java.lang.NoSuchMethodError Thrown if an application tries to call a specified method of a class (either static or instance), and that class no longer has a definition of that method.
OutOfMemoryError sample code for java.lang.OutOfMemoryError definition code for java.lang.OutOfMemoryError Thrown when the Java Virtual Machine cannot allocate an object because it is out of memory, and no more memory could be made available by the garbage collector.
StackOverflowError sample code for java.lang.StackOverflowError definition code for java.lang.StackOverflowError Thrown when a stack overflow occurs because an application recurses too deeply.
ThreadDeath sample code for java.lang.ThreadDeath definition code for java.lang.ThreadDeath An instance of ThreadDeath is thrown in the victim thread when the stop method with zero arguments in class Thread is called.
UnknownError sample code for java.lang.UnknownError definition code for java.lang.UnknownError Thrown when an unknown but serious exception has occurred in the Java Virtual Machine.
UnsatisfiedLinkError sample code for java.lang.UnsatisfiedLinkError definition code for java.lang.UnsatisfiedLinkError Thrown if the Java Virtual Machine cannot find an appropriate native-language definition of a method declared native.
UnsupportedClassVersionError sample code for java.lang.UnsupportedClassVersionError definition code for java.lang.UnsupportedClassVersionError Thrown when the Java Virtual Machine attempts to read a class file and determines that the major and minor version numbers in the file are not supported.
VerifyError sample code for java.lang.VerifyError definition code for java.lang.VerifyError Thrown when the "verifier" detects that a class file, though well formed, contains some sort of internal inconsistency or security problem.
VirtualMachineError sample code for java.lang.VirtualMachineError definition code for java.lang.VirtualMachineError Thrown to indicate that the Java Virtual Machine is broken or has run out of resources necessary for it to continue operating.

Annotation Types Summary
Deprecated A program element annotated @Deprecated is one that programmers are discouraged from using, typically because it is dangerous, or because a better alternative exists.
Override Indicates that a method declaration is intended to override a method declaration in a superclass.
SuppressWarnings Indicates that the named compiler warnings should be suppressed in the annotated element (and in all program elements contained in the annotated element).