home | O'Reilly's CD bookshelfs | FreeBSD | Linux | Cisco | Cisco Exam  

Java in a Nutshell

Previous Chapter 26
The java.lang.reflect Package

26.2 java.lang.reflect.Constructor (JDK 1.1)

This class represents a constructor method of a class. Instances of Constructor are obtained by calling getConstructor() and related methods of java.lang.Class. Constructor implements the Member interface, so you can use the methods of that interface to obtain the constructor name, modifiers, and declaring class. In addition, getParameterTypes() and getExceptionTypes() also return important information about the represented constructor.

In addition to these methods that return information about the constructor, the newInstance() method allows the constructor to be invoked with an array of arguments in order to create a new instance of the class that declares the constructor. If any of the arguments to the constructor are of primitive types, they must be converted to their corresponding wrapper object types in order to be passed to newInstance(). If the constructor causes an exception, the Throwable object it throws is wrapped within the InvocationTargetException that is thrown by newInstance(). Note that newInstance() is much more useful than the newInstance() method of java.lang.Class because it can pass arguments to the constructor.

public final class Constructor extends Object implements Member {
    // No Constructor
    // Public Instance Methods
            public boolean equals(Object obj);  // Overrides Object
            public Class getDeclaringClass();  // From Member
            public Class[] getExceptionTypes();
            public native int getModifiers();  // From Member
            public String getName();  // From Member
            public Class[] getParameterTypes();
            public int hashCode();  // Overrides Object
            public native Object newInstance(Object[] initargs) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException;
            public String toString();  // Overrides Object

Returned By:

Class.getConstructor(), Class.getConstructors(), Class.getDeclaredConstructor(), Class.getDeclaredConstructors()

Previous Home Next
java.lang.reflect.Array (JDK 1.1) Book Index java.lang.reflect.Field (JDK 1.1)

Java in a Nutshell Java Language Reference Java AWT Java Fundamental Classes Exploring Java