Arrays with identical type and number of dimensions share the same class.
* The array class ClassLoader is the same as the ClassLoader of the element
* type of the array (which can be null to indicate the bootstrap classloader).
* The name of an array class is [<signature format>;.
*
For example,
* String[]'s class is [Ljava.lang.String;. boolean, byte,
* short, char, int, long, float and double have the "type name" of
* Z,B,S,C,I,J,F,D for the purposes of array classes. If it's a
* multidimensioned array, the same principle applies:
* int[][][] == [[[I.
*
*
There is no public constructor - Class objects are obtained only through
* the virtual machine, as defined in ClassLoaders.
*
* @serialData Class objects serialize specially:
* Calls If the name you supply is absolute (it starts with a The URL returned is system- and classloader-dependent, and could
* change across implementations.
*
* @param resourceName the name of the resource, generally a path
* @return the URL to the resource
* @throws NullPointerException if name is null
* @since 1.1
*/
public URL getResource(String resourceName)
{
String name = resourcePath(resourceName);
ClassLoader loader = getClassLoaderInternal();
if (loader == null)
return ClassLoader.getSystemResource(name);
return loader.getResource(name);
}
/**
* Get a resource using this class's package using the
* getClassLoader().getResourceAsStream() method. If this class was loaded
* using the system classloader, ClassLoader.getSystemResource() is used
* instead.
*
* If the name you supply is absolute (it starts with a The URL returned is system- and classloader-dependent, and could
* change across implementations.
*
* @param resourceName the name of the resource, generally a path
* @return an InputStream with the contents of the resource in it, or null
* @throws NullPointerException if name is null
* @since 1.1
*/
public InputStream getResourceAsStream(String resourceName)
{
String name = resourcePath(resourceName);
ClassLoader loader = getClassLoaderInternal();
if (loader == null)
return ClassLoader.getSystemResourceAsStream(name);
return loader.getResourceAsStream(name);
}
private String resourcePath(String resourceName)
{
if (resourceName.length() > 0)
{
if (resourceName.charAt(0) != '/')
{
String pkg = getPackagePortion(getName());
if (pkg.length() > 0)
resourceName = pkg.replace('.','/') + '/' + resourceName;
}
else
{
resourceName = resourceName.substring(1);
}
}
return resourceName;
}
/**
* Get the signers of this class. This returns null if there are no signers,
* such as for primitive types or void.
*
* @return the signers of this class
* @since 1.1
*/
public native Object[] getSigners ();
/**
* Set the signers of this class.
*
* @param signers the signers of this class
*/
native void setSigners(Object[] signers);
/**
* Get the direct superclass of this class. If this is an interface,
* Object, a primitive type, or void, it will return null. If this is an
* array type, it will return Object.
*
* @return the direct superclass of this class
*/
public native Class getSuperclass ();
/**
* Return whether this class is an array type.
*
* @return whether this class is an array type
* @since 1.1
*/
public native boolean isArray ();
/**
* Discover whether an instance of the Class parameter would be an
* instance of this Class as well. Think of doing
*
* Casts this class to represent a subclass of the specified class.
* This method is useful for `narrowing' the type of a class so that
* the class object, and instances of that class, can match the contract
* of a more restrictive method. For example, if this class has the
* static type of
* If this class can be converted to an instance which is parameterised
* over a subtype of the supplied type,
* Returns an array of
* If one of the superinterfaces is a parameterized type, then the
* object returned for this interface reflects the actual type
* parameters used in the source code. Type parameters are created
* using the semantics specified by the
* The order of the interfaces in the array matches the order in which
* the interfaces are declared. For classes which represent an array,
* an array of two interfaces,
* Returns a
* If the superclass is a parameterized type, then the
* object returned for this interface reflects the actual type
* parameters used in the source code. Type parameters are created
* using the semantics specified by the
* Returns the canonical name of this class, as defined by section
* 6.7 of the Java language specification. Each package, top-level class,
* top-level interface and primitive type has a canonical name. A member
* class has a canonical name, if its parent class has one. Likewise,
* an array type has a canonical name, if its component type does.
* Local or anonymous classes do not have canonical names.
*
* The canonical name for top-level classes, top-level interfaces and
* primitive types is always the same as the fully-qualified name.
* For array types, the canonical name is the canonical name of its
* component type with `[]' appended.
*
* The canonical name of a member class always refers to the place where
* the class was defined, and is composed of the canonical name of the
* defining class and the simple name of the member class, joined by `.'.
* For example, if a
* Where no canonical name is present, TC_CLASS ClassDescriptor. For more serialization information,
* see {@link ObjectStreamClass}.
*
* @author John Keiser
* @author Eric Blake (ebb9@email.byu.edu)
* @author Tom Tromey (tromey@cygnus.com)
* @since 1.0
* @see ClassLoader
*/
public final class ClassClass.forName(name, true, getClass().getClassLoader()).
*
* @param name the name of the class to find
* @return the Class object representing the class
* @throws ClassNotFoundException if the class was not found by the
* classloader
* @throws LinkageError if linking the class fails
* @throws ExceptionInInitializerError if the class loads, but an exception
* occurs during initialization
*/
public static native Class forName (String className)
throws ClassNotFoundException;
// A private internal method that is called by compiler-generated code.
private static Class forName (String className, Class caller)
throws ClassNotFoundException
{
return forName(className, true, caller.getClassLoaderInternal());
}
/**
* Use the specified classloader to load and link a class. If the loader
* is null, this uses the bootstrap class loader (provide the security
* check succeeds). Unfortunately, this method cannot be used to obtain
* the Class objects for primitive types or for void, you have to use
* the fields in the appropriate java.lang wrapper classes.
*
* classloader.loadclass(name, initialize).
*
* @param name the name of the class to find
* @param initialize whether or not to initialize the class at this time
* @param classloader the classloader to use to find the class; null means
* to use the bootstrap class loader
* @throws ClassNotFoundException if the class was not found by the
* classloader
* @throws LinkageError if linking the class fails
* @throws ExceptionInInitializerError if the class loads, but an exception
* occurs during initialization
* @throws SecurityException if the classloader argument
* is null and the caller does not have the
* RuntimePermission("getClassLoader") permission
* @see ClassLoader
* @since 1.2
*/
public static native Class forName (String className, boolean initialize,
ClassLoader loader)
throws ClassNotFoundException;
/**
* Get all the public member classes and interfaces declared in this
* class or inherited from superclasses. This returns an array of length
* 0 if there are no member classes, including for primitive types. A
* security check may be performed, with
* checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @return all public member classes in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Class[] getClasses()
{
memberAccessCheck(Member.PUBLIC);
return internalGetClasses();
}
/**
* Like getClasses() but without the security checks.
*/
private Class[] internalGetClasses()
{
ArrayListRuntimePermission("getClassLoader")
* must first succeed. Primitive types and void return null.
*
* @return the ClassLoader that loaded this class
* @throws SecurityException if the security check fails
* @see ClassLoader
* @see RuntimePermission
*/
public native ClassLoader getClassLoader ();
// A private internal method that is called by compiler-generated code.
private final native ClassLoader getClassLoader (Class caller);
/**
* Internal method that circumvents the usual security checks when
* getting the class loader.
*/
private native ClassLoader getClassLoaderInternal ();
/**
* If this is an array, get the Class representing the type of array.
* Examples: "[[Ljava.lang.String;" would return "[Ljava.lang.String;", and
* calling getComponentType on that would give "java.lang.String". If
* this is not an array, returns null.
*
* @return the array type of this class, or null
* @see Array
* @since 1.1
*/
public native Class getComponentType ();
/**
* Get a public constructor declared in this class. If the constructor takes
* no argument, an array of zero elements and null are equivalent for the
* types argument. A security check may be performed, with
* checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @param types the type of each parameter
* @return the constructor
* @throws NoSuchMethodException if the constructor does not exist
* @throws SecurityException if the security check fails
* @see #getConstructors()
* @since 1.1
*/
public native ConstructorcheckMemberAccess(this, Member.PUBLIC)
* as well as checkPackageAccess both having to succeed.
*
* @return all public constructors in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Constructor[] getConstructors()
{
memberAccessCheck(Member.PUBLIC);
return getDeclaredConstructors(true);
}
/**
* Get a constructor declared in this class. If the constructor takes no
* argument, an array of zero elements and null are equivalent for the
* types argument. A security check may be performed, with
* checkMemberAccess(this, Member.DECLARED) as well as
* checkPackageAccess both having to succeed.
*
* @param types the type of each parameter
* @return the constructor
* @throws NoSuchMethodException if the constructor does not exist
* @throws SecurityException if the security check fails
* @see #getDeclaredConstructors()
* @since 1.1
*/
public native ConstructorcheckMemberAccess(this, Member.DECLARED) as well as
* checkPackageAccess both having to succeed.
*
* @return all declared member classes in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Class[] getDeclaredClasses()
{
memberAccessCheck(Member.DECLARED);
return getDeclaredClasses(false);
}
native Class[] getDeclaredClasses (boolean publicOnly);
/**
* Get all the declared constructors of this class. This returns an array of
* length 0 if there are no constructors, including for primitive types,
* arrays, and interfaces. It does, however, include the default
* constructor if one was supplied by the compiler. A security check may
* be performed, with checkMemberAccess(this, Member.DECLARED)
* as well as checkPackageAccess both having to succeed.
*
* @return all constructors in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Constructor[] getDeclaredConstructors()
{
memberAccessCheck(Member.DECLARED);
return getDeclaredConstructors(false);
}
native Constructor[] getDeclaredConstructors (boolean publicOnly);
/**
* Get a field declared in this class, where name is its simple name. The
* implicit length field of arrays is not available. A security check may
* be performed, with checkMemberAccess(this, Member.DECLARED)
* as well as checkPackageAccess both having to succeed.
*
* @param name the name of the field
* @return the field
* @throws NoSuchFieldException if the field does not exist
* @throws SecurityException if the security check fails
* @see #getDeclaredFields()
* @since 1.1
*/
public native Field getDeclaredField(String fieldName)
throws NoSuchFieldException;
/**
* Get all the declared fields in this class, but not those inherited from
* superclasses. This returns an array of length 0 if there are no fields,
* including for primitive types. This does not return the implicit length
* field of arrays. A security check may be performed, with
* checkMemberAccess(this, Member.DECLARED) as well as
* checkPackageAccess both having to succeed.
*
* @return all declared fields in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Field[] getDeclaredFields()
{
memberAccessCheck(Member.DECLARED);
return getDeclaredFields(false);
}
native Field[] getDeclaredFields (boolean publicOnly);
private native Method _getDeclaredMethod(String methodName, Class[] args);
/**
* Get a method declared in this class, where name is its simple name. The
* implicit methods of Object are not available from arrays or interfaces.
* Constructors (named "<init>" in the class file) and class initializers
* (name "<clinit>") are not available. The Virtual Machine allows
* multiple methods with the same signature but differing return types; in
* such a case the most specific return types are favored, then the final
* choice is arbitrary. If the method takes no argument, an array of zero
* elements and null are equivalent for the types argument. A security
* check may be performed, with
* checkMemberAccess(this, Member.DECLARED) as well as
* checkPackageAccess both having to succeed.
*
* @param methodName the name of the method
* @param types the type of each parameter
* @return the method
* @throws NoSuchMethodException if the method does not exist
* @throws SecurityException if the security check fails
* @see #getDeclaredMethods()
* @since 1.1
*/
public Method getDeclaredMethod(String methodName, Class... args)
throws NoSuchMethodException
{
memberAccessCheck(Member.DECLARED);
if ("checkMemberAccess(this, Member.DECLARED) as well as
* checkPackageAccess both having to succeed.
*
* @return all declared methods in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public native Method[] getDeclaredMethods();
/**
* If this is a nested or inner class, return the class that declared it.
* If not, return null.
*
* @return the declaring class of this class
* @since 1.1
*/
// This is marked as unimplemented in the JCL book.
public native Class getDeclaringClass ();
private native Field getField (String fieldName, int hash)
throws NoSuchFieldException;
/**
* Get a public field declared or inherited in this class, where name is
* its simple name. If the class contains multiple accessible fields by
* that name, an arbitrary one is returned. The implicit length field of
* arrays is not available. A security check may be performed, with
* checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @param fieldName the name of the field
* @return the field
* @throws NoSuchFieldException if the field does not exist
* @throws SecurityException if the security check fails
* @see #getFields()
* @since 1.1
*/
public Field getField(String fieldName)
throws NoSuchFieldException
{
memberAccessCheck(Member.PUBLIC);
Field field = getField(fieldName, fieldName.hashCode());
if (field == null)
throw new NoSuchFieldException(fieldName);
return field;
}
/**
* Get all the public fields declared in this class or inherited from
* superclasses. This returns an array of length 0 if there are no fields,
* including for primitive types. This does not return the implicit length
* field of arrays. A security check may be performed, with
* checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @return all public fields in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public Field[] getFields()
{
memberAccessCheck(Member.PUBLIC);
return internalGetFields();
}
/**
* Like getFields() but without the security checks.
*/
private Field[] internalGetFields()
{
LinkedHashSet set = new LinkedHashSet();
set.addAll(Arrays.asList(getDeclaredFields(true)));
Class[] interfaces = getInterfaces();
for (int i = 0; i < interfaces.length; i++)
set.addAll(Arrays.asList(interfaces[i].internalGetFields()));
Class superClass = getSuperclass();
if (superClass != null)
set.addAll(Arrays.asList(superClass.internalGetFields()));
return (Field[])set.toArray(new Field[set.size()]);
}
/**
* Returns the Package in which this class is defined
* Returns null when this information is not available from the
* classloader of this class.
*
* @return the package for this class, if it is available
* @since 1.2
*/
public Package getPackage()
{
ClassLoader cl = getClassLoaderInternal();
if (cl != null)
return cl.getPackage(getPackagePortion(getName()));
else
return VMClassLoader.getPackage(getPackagePortion(getName()));
}
/**
* Get the interfaces this class directly implements, in the
* order that they were declared. This returns an empty array, not null,
* for Object, primitives, void, and classes or interfaces with no direct
* superinterface. Array types return Cloneable and Serializable.
*
* @return the interfaces this class directly implements
*/
public native Class[] getInterfaces ();
private final native void getSignature(StringBuffer buffer);
private static final native String getSignature(Class[] args,
boolean is_construtor);
public native Method _getMethod(String methodName, Class[] args);
/**
* Get a public method declared or inherited in this class, where name is
* its simple name. The implicit methods of Object are not available from
* interfaces. Constructors (named "<init>" in the class file) and class
* initializers (name "<clinit>") are not available. The Virtual
* Machine allows multiple methods with the same signature but differing
* return types, and the class can inherit multiple methods of the same
* return type; in such a case the most specific return types are favored,
* then the final choice is arbitrary. If the method takes no argument, an
* array of zero elements and null are equivalent for the types argument.
* A security check may be performed, with
* checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @param methodName the name of the method
* @param types the type of each parameter
* @return the method
* @throws NoSuchMethodException if the method does not exist
* @throws SecurityException if the security check fails
* @see #getMethods()
* @since 1.1
*/
public Method getMethod(String methodName, Class... args)
throws NoSuchMethodException
{
memberAccessCheck(Member.PUBLIC);
if ("checkMemberAccess(this, Member.PUBLIC) as well as
* checkPackageAccess both having to succeed.
*
* @return all public methods in this class
* @throws SecurityException if the security check fails
* @since 1.1
*/
public native Method[] getMethods();
/**
* Get the modifiers of this class. These can be decoded using Modifier,
* and is limited to one of public, protected, or private, and any of
* final, static, abstract, or interface. An array class has the same
* public, protected, or private modifier as its component type, and is
* marked final but not an interface. Primitive types and void are marked
* public and final, but not an interface.
*
* @return the modifiers of this class
* @see Modifer
* @since 1.1
*/
public native int getModifiers ();
/**
* Get the name of this class, separated by dots for package separators.
* If the class represents a primitive type, or void, then the
* name of the type as it appears in the Java programming language
* is returned. For instance, Byte.TYPE.getName()
* returns "byte".
*
* Arrays are specially encoded as shown on this table.
*
* array type [element type
* (note that the element type is encoded per
* this table)
* boolean Z
* byte B
* char C
* short S
* int I
* long J
* float F
* double D
* void V
* class or interface, alone: <dotted name>
* class or interface, as element type: L<dotted name>;
*
*
* @return the name of this class
*/
public native String getName ();
/**
* Get a resource URL using this class's package using the
* getClassLoader().getResource() method. If this class was loaded using
* the system classloader, ClassLoader.getSystemResource() is used instead.
*
* /),
* then the leading / is removed and it is passed on to
* getResource(). If it is relative, the package name is prepended, and
* .'s are replaced with /.
*
* /),
* then the leading / is removed and it is passed on to
* getResource(). If it is relative, the package name is prepended, and
* .'s are replaced with /.
*
* isInstance(c.newInstance()) or even
* c.newInstance() instanceof (this class). While this
* checks widening conversions for objects, it must be exact for primitive
* types.
*
* @param c the class to check
* @return whether an instance of c would be an instance of this class
* as well
* @throws NullPointerException if c is null
* @since 1.1
*/
public native boolean isAssignableFrom (Class c);
/**
* Discover whether an Object is an instance of this Class. Think of it
* as almost like o instanceof (this class).
*
* @param o the Object to check
* @return whether o is an instance of this class
* @since 1.1
*/
public native boolean isInstance (Object o);
/**
* Check whether this class is an interface or not. Array types are not
* interfaces.
*
* @return whether this class is an interface or not
*/
public native boolean isInterface ();
/**
* Return whether this class is a primitive type. A primitive type class
* is a class representing a kind of "placeholder" for the various
* primitive types, or void. You can access the various primitive type
* classes through java.lang.Boolean.TYPE, java.lang.Integer.TYPE, etc.,
* or through boolean.class, int.class, etc.
*
* @return whether this class is a primitive type
* @see Boolean#TYPE
* @see Byte#TYPE
* @see Character#TYPE
* @see Short#TYPE
* @see Integer#TYPE
* @see Long#TYPE
* @see Float#TYPE
* @see Double#TYPE
* @see Void#TYPE
* @since 1.1
*/
public native boolean isPrimitive ();
/**
* Get a new instance of this class by calling the no-argument constructor.
* The class is initialized if it has not been already. A security check
* may be performed, with checkMemberAccess(this, Member.PUBLIC)
* as well as checkPackageAccess both having to succeed.
*
* @return a new instance of this class
* @throws InstantiationException if there is not a no-arg constructor
* for this class, including interfaces, abstract classes, arrays,
* primitive types, and void; or if an exception occurred during
* the constructor
* @throws IllegalAccessException if you are not allowed to access the
* no-arg constructor because of scoping reasons
* @throws SecurityException if the security check fails
* @throws ExceptionInInitializerError if class initialization caused by
* this call fails with an exception
*/
public native T newInstance ()
throws InstantiationException, IllegalAccessException;
// We need a native method to retrieve the protection domain, because we
// can't add fields to java.lang.Class that are accessible from Java.
private native ProtectionDomain getProtectionDomain0();
/**
* Returns the protection domain of this class. If the classloader did not
* record the protection domain when creating this class the unknown
* protection domain is returned which has a null code source
* and all permissions. A security check may be performed, with
* RuntimePermission("getProtectionDomain").
*
* @return the protection domain
* @throws SecurityException if the security manager exists and the caller
* does not have RuntimePermission("getProtectionDomain").
* @see RuntimePermission
* @since 1.2
*/
public ProtectionDomain getProtectionDomain()
{
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkPermission(VMClassLoader.protectionDomainPermission);
ProtectionDomain protectionDomain = getProtectionDomain0();
if (protectionDomain == null)
return VMClassLoader.unknownProtectionDomain;
else
return protectionDomain;
}
/**
* Return the human-readable form of this Object. For an object, this
* is either "interface " or "class " followed by getName(),
* for primitive types and void it is just getName().
*
* @return the human-readable form of this Object
*/
public String toString()
{
if (isPrimitive())
return getName();
return (isInterface() ? "interface " : "class ") + getName();
}
/**
* Returns the desired assertion status of this class, if it were to be
* initialized at this moment. The class assertion status, if set, is
* returned; the backup is the default package status; then if there is
* a class loader, that default is returned; and finally the system default
* is returned. This method seldom needs calling in user code, but exists
* for compilers to implement the assert statement. Note that there is no
* guarantee that the result of this method matches the class's actual
* assertion status.
*
* @return the desired assertion status
* @see ClassLoader#setClassAssertionStatus(String, boolean)
* @see ClassLoader#setPackageAssertionStatus(String, boolean)
* @see ClassLoader#setDefaultAssertionStatus(boolean)
* @since 1.4
*/
public boolean desiredAssertionStatus()
{
ClassLoader c = getClassLoaderInternal();
Object status;
if (c == null)
return VMClassLoader.defaultAssertionStatus();
if (c.classAssertionStatus != null)
synchronized (c)
{
status = c.classAssertionStatus.get(getName());
if (status != null)
return status.equals(Boolean.TRUE);
}
else
{
status = ClassLoader.systemClassAssertionStatus.get(getName());
if (status != null)
return status.equals(Boolean.TRUE);
}
if (c.packageAssertionStatus != null)
synchronized (c)
{
String name = getPackagePortion(getName());
if ("".equals(name))
status = c.packageAssertionStatus.get(null);
else
do
{
status = c.packageAssertionStatus.get(name);
name = getPackagePortion(name);
}
while (! "".equals(name) && status == null);
if (status != null)
return status.equals(Boolean.TRUE);
}
else
{
String name = getPackagePortion(getName());
if ("".equals(name))
status = ClassLoader.systemPackageAssertionStatus.get(null);
else
do
{
status = ClassLoader.systemPackageAssertionStatus.get(name);
name = getPackagePortion(name);
}
while (! "".equals(name) && status == null);
if (status != null)
return status.equals(Boolean.TRUE);
}
return c.defaultAssertionStatus;
}
/**
* Strip the last portion of the name (after the last dot).
*
* @param name the name to get package of
* @return the package name, or "" if no package
*/
private static String getPackagePortion(String name)
{
int lastInd = name.lastIndexOf('.');
if (lastInd == -1)
return "";
return name.substring(0, lastInd);
}
/**
* Perform security checks common to all of the methods that
* get members of this Class.
*/
private void memberAccessCheck(int which)
{
SecurityManager sm = System.getSecurityManager();
if (sm != null)
{
sm.checkMemberAccess(this, which);
Package pkg = getPackage();
if (pkg != null)
sm.checkPackageAccess(pkg.getName());
}
}
/**
* Class<Object>, and a dynamic type of
* Class<Rectangle>, then, assuming Shape is
* a superclass of Rectangle, this method can be used on
* this class with the parameter, Class<Shape>, to retain
* the same instance but with the type
* Class<? extends Shape>.
* U, then this method
* returns an appropriately cast reference to this object. Otherwise,
* a ClassCastException is thrown.
* U) of
* which should be a superclass of the parameterized type of
* this instance.
* @return a reference to this object, appropriately cast.
* @throws ClassCastException if this class can not be converted to one
* which represents a subclass of the specified
* type, U.
* @since 1.5
*/
public Class asSubclass(Class klass)
{
if (! klass.isAssignableFrom(this))
throw new ClassCastException();
return (Class) this;
}
/**
* Returns the specified object, cast to this Class' type.
*
* @param obj the object to cast
* @throws ClassCastException if obj is not an instance of this class
* @since 1.5
*/
public T cast(Object obj)
{
if (obj != null && ! isInstance(obj))
throw new ClassCastException();
return (T) obj;
}
/**
* Returns the enumeration constants of this class, or
* null if this class is not an Enum.
*
* @return an array of Enum constants
* associated with this class, or null if this
* class is not an enum.
* @since 1.5
*/
public T[] getEnumConstants()
{
if (isEnum())
{
try
{
Method m = getMethod("values");
setAccessible(m);
return (T[]) m.invoke(null);
}
catch (NoSuchMethodException exception)
{
throw new Error("Enum lacks values() method");
}
catch (IllegalAccessException exception)
{
throw new Error("Unable to access Enum class");
}
catch (InvocationTargetException exception)
{
throw new
RuntimeException("The values method threw an exception",
exception);
}
}
else
{
return null;
}
}
/**
* Returns true if this class is an Enum.
*
* @return true if this is an enumeration class.
* @since 1.5
*/
public native boolean isEnum();
/**
* Returns true if this class is a synthetic class, generated by
* the compiler.
*
* @return true if this is a synthetic class.
* @since 1.5
*/
public native boolean isSynthetic();
/**
* Returns true if this class is an Annotation.
*
* @return true if this is an annotation class.
* @since 1.5
*/
public native boolean isAnnotation();
/**
* Returns the simple name for this class, as used in the source
* code. For normal classes, this is the content returned by
* getName() which follows the last ".". Anonymous
* classes have no name, and so the result of calling this method is
* "". The simple name of an array consists of the simple name of
* its component type, followed by "[]". Thus, an array with the
* component type of an anonymous class has a simple name of simply
* "[]".
*
* @return the simple name for this class.
* @since 1.5
*/
public String getSimpleName()
{
StringBuffer sb = new StringBuffer();
Class klass = this;
int arrayCount = 0;
while (klass.isArray())
{
klass = klass.getComponentType();
++arrayCount;
}
if (! klass.isAnonymousClass())
{
String fullName = klass.getName();
sb.append(fullName, fullName.lastIndexOf(".") + 1, fullName.length());
}
while (arrayCount-- > 0)
sb.append("[]");
return sb.toString();
}
/**
* Returns the class which immediately encloses this class. If this class
* is a top-level class, this method returns null.
*
* @return the immediate enclosing class, or null if this is
* a top-level class.
* @since 1.5
*/
public native Class getEnclosingClass();
/**
* Returns the constructor which immediately encloses this class. If
* this class is a top-level class, or a local or anonymous class
* immediately enclosed by a type definition, instance initializer
* or static initializer, then null is returned.
*
* @return the immediate enclosing constructor if this class is
* declared within a constructor. Otherwise, null
* is returned.
* @since 1.5
*/
public native Constructornull is returned.
*
* @return the immediate enclosing method if this class is
* declared within a method. Otherwise, null
* is returned.
* @since 1.5
*/
public native Method getEnclosingMethod();
private native String getClassSignature();
/**
* Type objects which represent the
* interfaces directly implemented by this class or extended by this
* interface.
* ParameterizedType
* interface, and only if an instance has not already been created.
* Cloneable and
* Serializable, is always returned, with the objects in
* that order. A class representing a primitive type or void always
* returns an array of zero size.
* Type object representing the direct superclass,
* whether class, interface, primitive type or void, of this class.
* If this class is an array class, then a class instance representing
* the Object class is returned. If this class is primitive,
* an interface, or a representation of either the Object
* class or void, then null is returned.
* ParameterizedType
* interface, and only if an instance has not already been created.
* TypeVariable objects that represents
* the type variables declared by this class, in declaration order.
* An array of size zero is returned if this class has no type
* variables.
*
* @return the type variables associated with this class.
* @throws GenericSignatureFormatError if the generic signature does
* not conform to the format specified in the Virtual Machine
* specification, version 3.
* @since 1.5
*/
public TypeVariablenull if no such annotation exists.
*
* @param annotationClass the type of annotation to look for.
* @return this class' annotation for the specified type, or
* null if no such annotation exists.
* @since 1.5
*/
public A getAnnotation(Class annotationClass)
{
A foundAnnotation = null;
Annotation[] annotations = getAnnotations();
for (Annotation annotation : annotations)
if (annotation.annotationType() == annotationClass)
foundAnnotation = (A) annotation;
return foundAnnotation;
}
/**
* Returns all annotations associated with this class. If there are
* no annotations associated with this class, then a zero-length array
* will be returned. The returned array may be modified by the client
* code, but this will have no effect on the annotation content of this
* class, and hence no effect on the return value of this method for
* future callers.
*
* @return this class' annotations.
* @since 1.5
*/
public Annotation[] getAnnotations()
{
HashMapPerson class has an inner class,
* M, then both its fully-qualified name and canonical name
* is Person.M. A subclass, Staff, of
* Person refers to the same inner class by the fully-qualified
* name of Staff.M, but its canonical name is still
* Person.M.
* null is returned.
* null if the
* class doesn't have a canonical name.
* @since 1.5
*/
public String getCanonicalName()
{
if (isArray())
{
String componentName = getComponentType().getCanonicalName();
if (componentName != null)
return componentName + "[]";
}
if (isMemberClass())
{
String memberName = getDeclaringClass().getCanonicalName();
if (memberName != null)
return memberName + "." + getSimpleName();
}
if (isLocalClass() || isAnonymousClass())
return null;
return getName();
}
/**
* Returns all annotations directly defined by this class. If there are
* no annotations associated with this class, then a zero-length array
* will be returned. The returned array may be modified by the client
* code, but this will have no effect on the annotation content of this
* class, and hence no effect on the return value of this method for
* future callers.
*
* @return the annotations directly defined by this class.
* @since 1.5
*/
public Annotation[] getDeclaredAnnotations()
{
Annotation[] result = getDeclaredAnnotationsInternal();
if (result == null)
result = new Annotation[0];
return result;
}
private native Annotation[] getDeclaredAnnotationsInternal();
/**
* Returns true if an annotation for the specified type is associated
* with this class. This is primarily a short-hand for using marker
* annotations.
*
* @param annotationClass the type of annotation to look for.
* @return true if an annotation exists for the specified type.
* @since 1.5
*/
public boolean isAnnotationPresent(Class
annotationClass)
{
return getAnnotation(annotationClass) != null;
}
/**
* Returns true if this object represents an anonymous class.
*
* @return true if this object represents an anonymous class.
* @since 1.5
*/
public native boolean isAnonymousClass();
/**
* Returns true if this object represents an local class.
*
* @return true if this object represents an local class.
* @since 1.5
*/
public native boolean isLocalClass();
/**
* Returns true if this object represents an member class.
*
* @return true if this object represents an member class.
* @since 1.5
*/
public native boolean isMemberClass();
/**
* Utility method for use by classes in this package.
*/
static void setAccessible(final AccessibleObject obj)
{
AccessController.doPrivileged(new PrivilegedAction()
{
public Object run()
{
obj.setAccessible(true);
return null;
}
});
}
}