com.google.gwt.emul.java.lang.reflect.Constructor Maven / Gradle / Ivy
package java.lang.reflect;
import java.lang.annotation.Annotation;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.UnsafeNativeLong;
/**
* Constructor provides information about, and access to, a single
* constructor for a class.
*
* Constructor permits widening conversions to occur when matching the
* actual parameters to newInstance() with the underlying
* constructor's formal parameters, but throws an
* IllegalArgumentException if a narrowing conversion would occur.
*
* @param the class in which the constructor is declared
*
* @see Member
* @see java.lang.Class
* @see java.lang.Class#getConstructors()
* @see java.lang.Class#getConstructor(Class[])
* @see java.lang.Class#getDeclaredConstructors()
*
* @author Kenneth Russell
* @author Nakul Saraiya
*/
public class Constructor extends AccessibleObject implements
GenericDeclaration,
Member {
private static final Class[] EMPTY_CLASSES = new Class[0];
private static final Annotation[] EMPTY_ANNOTATIONS = new Annotation[0];
private Class clazz;
private int slot;
private Class[] parameterTypes;
private Class[] exceptionTypes;
private int modifiers;
private transient String signature;
private JavaScriptObject method;
private Annotation[] annos;
private static final int LANGUAGE_MODIFIERS =
Modifier.PUBLIC | Modifier.PROTECTED | Modifier.PRIVATE;
protected Constructor() {
this.parameterTypes = exceptionTypes = EMPTY_CLASSES;
this.annos = EMPTY_ANNOTATIONS;
}
/**
* Public constructor to allow gwt to create constructors anywhere
*/
public Constructor(Class from, int modifiers, JavaScriptObject method, Annotation[] annos,
Class[] params, Class[] exceptions) {
this.clazz = from;
this.modifiers = modifiers;
// TODO implement these
this.signature = "";
this.method = method;
this.annos = annos;
this.parameterTypes = params;
this.exceptionTypes = exceptions;
}
/**
* Pure JRE must copy constructors to manage accessibility.
*
* We, on the other hand, can stick with a single object and uncap access.
*/
Constructor copy() {
return this;
}
/**
* Returns the Class object representing the class that declares
* the constructor represented by this Constructor object.
*/
public Class getDeclaringClass() {
return clazz;
}
/**
* Returns the name of this constructor, as a string. This is
* always the same as the simple name of the constructor's declaring
* class.
*/
public String getName() {
return getDeclaringClass().getSimpleName();
}
/**
* Returns the Java language modifiers for the constructor
* represented by this Constructor object, as an integer. The
* Modifier class should be used to decode the modifiers.
*
* @see Modifier
*/
public int getModifiers() {
return modifiers;
}
/**
* Returns an array of TypeVariable objects that represent the
* type variables declared by the generic declaration represented by this
* GenericDeclaration object, in declaration order. Returns an
* array of length 0 if the underlying generic declaration declares no type
* variables.
*
* @return an array of TypeVariable objects that represent
* the type variables declared by this generic declaration
* @throws GenericSignatureFormatError if the generic
* signature of this generic declaration does not conform to
* the format specified in the Java Virtual Machine Specification,
* 3rd edition
* @since 1.5
*/
public TypeVariable>[] getTypeParameters() {
// if (getSignature() != null) {
// return (TypeVariable>[])getGenericInfo().getTypeParameters();
// } else
return (TypeVariable>[])new TypeVariable[0];
}
/**
* Returns an array of Class objects that represent the formal
* parameter types, in declaration order, of the constructor
* represented by this Constructor object. Returns an array of
* length 0 if the underlying constructor takes no parameters.
*
* @return the parameter types for the constructor this object
* represents
*/
public Class[] getParameterTypes() {
return (Class[]) parameterTypes;//used to be a clone.
//We should make this immutable... or implement clone.
}
/**
* Returns an array of Type objects that represent the formal
* parameter types, in declaration order, of the method represented by
* this Constructor object. Returns an array of length 0 if the
* underlying method takes no parameters.
*
* If a formal parameter type is a parameterized type,
* the Type object returned for it must accurately reflect
* the actual type parameters used in the source code.
*
*
If a formal parameter type is a type variable or a parameterized
* type, it is created. Otherwise, it is resolved.
*
* @return an array of Types that represent the formal
* parameter types of the underlying method, in declaration order
* @throws GenericSignatureFormatError
* if the generic method signature does not conform to the format
* specified in the Java Virtual Machine Specification, 3rd edition
* @throws TypeNotPresentException if any of the parameter
* types of the underlying method refers to a non-existent type
* declaration
* @throws MalformedParameterizedTypeException if any of
* the underlying method's parameter types refer to a parameterized
* type that cannot be instantiated for any reason
* @since 1.5
*/
public Type[] getGenericParameterTypes() {
// if (getSignature() != null)
// return getGenericInfo().getParameterTypes();
// else
return getTypeParameters();
}
/**
* Returns an array of Class objects that represent the types
* of exceptions declared to be thrown by the underlying constructor
* represented by this Constructor object. Returns an array of
* length 0 if the constructor declares no exceptions in its throws clause.
*
* @return the exception types declared as being thrown by the
* constructor this object represents
*/
public Class[] getExceptionTypes() {
return (Class[])exceptionTypes;//.clone();
}
/**
* Returns an array of Type objects that represent the
* exceptions declared to be thrown by this Constructor object.
* Returns an array of length 0 if the underlying method declares
* no exceptions in its throws clause.
*
*
If an exception type is a parameterized type, the Type
* object returned for it must accurately reflect the actual type
* parameters used in the source code.
*
*
If an exception type is a type variable or a parameterized
* type, it is created. Otherwise, it is resolved.
*
* @return an array of Types that represent the exception types
* thrown by the underlying method
* @throws GenericSignatureFormatError
* if the generic method signature does not conform to the format
* specified in the Java Virtual Machine Specification, 3rd edition
* @throws TypeNotPresentException if the underlying method's
* throws clause refers to a non-existent type declaration
* @throws MalformedParameterizedTypeException if
* the underlying method's throws clause refers to a
* parameterized type that cannot be instantiated for any reason
* @since 1.5
*/
public Type[] getGenericExceptionTypes() {
// Type[] result;
// if (getSignature() != null &&
// ( (result = getGenericInfo().getExceptionTypes()).length > 0 ))
// return result;
// else
return getExceptionTypes();
}
/**
* Compares this Constructor against the specified object.
* Returns true if the objects are the same. Two Constructor objects are
* the same if they were declared by the same class and have the
* same formal parameter types.
*/
@Override
public boolean equals(Object obj) {
if (obj != null && obj instanceof Constructor) {
Constructor other = (Constructor)obj;
if (getDeclaringClass() == other.getDeclaringClass()) {
/* Avoid unnecessary cloning */
Class[] params1 = parameterTypes;
Class[] params2 = other.parameterTypes;
if (params1.length == params2.length) {
for (int i = 0; i < params1.length; i++) {
if (params1[i] != params2[i])
return false;
}
return true;
}
}
}
return false;
}
/**
* Returns a hashcode for this Constructor. The hashcode is
* the same as the hashcode for the underlying constructor's
* declaring class name.
*/
@Override
public int hashCode() {
return getDeclaringClass().getName().hashCode();
}
/**
* Returns a string describing this Constructor. The string is
* formatted as the constructor access modifiers, if any,
* followed by the fully-qualified name of the declaring class,
* followed by a parenthesized, comma-separated list of the
* constructor's formal parameter types. For example:
*
* public java.util.Hashtable(int,float)
*
*
* The only possible modifiers for constructors are the access
* modifiers public, protected or
* private. Only one of these may appear, or none if the
* constructor has default (package) access.
*/
@Override
public String toString() {
try {
StringBuffer sb = new StringBuffer();
int mod = getModifiers() & LANGUAGE_MODIFIERS;
if (mod != 0) {
sb.append(Modifier.toString(mod) + " ");
}
sb.append(Field.getTypeName(getDeclaringClass()));
sb.append("(");
Class[] params = parameterTypes; // avoid clone
for (int j = 0; j < params.length; j++) {
sb.append(Field.getTypeName(params[j]));
if (j < (params.length - 1))
sb.append(",");
}
sb.append(")");
Class[] exceptions = exceptionTypes; // avoid clone
if (exceptions.length > 0) {
sb.append(" throws ");
for (int k = 0; k < exceptions.length; k++) {
sb.append(exceptions[k].getName());
if (k < (exceptions.length - 1))
sb.append(",");
}
}
return sb.toString();
} catch (Exception e) {
return "<" + e + ">";
}
}
/**
* Returns a string describing this Constructor,
* including type parameters. The string is formatted as the
* constructor access modifiers, if any, followed by an
* angle-bracketed comma separated list of the constructor's type
* parameters, if any, followed by the fully-qualified name of the
* declaring class, followed by a parenthesized, comma-separated
* list of the constructor's generic formal parameter types. A
* space is used to separate access modifiers from one another and
* from the type parameters or return type. If there are no type
* parameters, the type parameter list is elided; if the type
* parameter list is present, a space separates the list from the
* class name. If the constructor is declared to throw
* exceptions, the parameter list is followed by a space, followed
* by the word "throws" followed by a
* comma-separated list of the thrown exception types.
*
*
The only possible modifiers for constructors are the access
* modifiers public, protected or
* private. Only one of these may appear, or none if the
* constructor has default (package) access.
*
* @return a string describing this Constructor,
* include type parameters
*
* @since 1.5
*/
public String toGenericString() {
try {
StringBuilder sb = new StringBuilder();
int mod = getModifiers() & LANGUAGE_MODIFIERS;
if (mod != 0) {
sb.append(Modifier.toString(mod) + " ");
}
Type[] typeparms = getTypeParameters();
if (typeparms.length > 0) {
boolean first = true;
sb.append("<");
for(Type typeparm: typeparms) {
if (!first)
sb.append(",");
if (typeparm instanceof Class)
sb.append(((Class)typeparm).getName());
else
sb.append(typeparm.toString());
first = false;
}
sb.append("> ");
}
sb.append(Field.getTypeName(getDeclaringClass()));
sb.append("(");
Type[] params = getGenericParameterTypes();
for (int j = 0; j < params.length; j++) {
sb.append((params[j] instanceof Class)?
Field.getTypeName((Class)params[j]):
(params[j].toString()) );
if (j < (params.length - 1))
sb.append(",");
}
sb.append(")");
Type[] exceptions = getGenericExceptionTypes();
if (exceptions.length > 0) {
sb.append(" throws ");
for (int k = 0; k < exceptions.length; k++) {
sb.append((exceptions[k] instanceof Class)?
((Class)exceptions[k]).getName():
exceptions[k].toString());
if (k < (exceptions.length - 1))
sb.append(",");
}
}
return sb.toString();
} catch (Exception e) {
return "<" + e + ">";
}
}
/**
* Uses the constructor represented by this Constructor object to
* create and initialize a new instance of the constructor's
* declaring class, with the specified initialization parameters.
* Individual parameters are automatically unwrapped to match
* primitive formal parameters, and both primitive and reference
* parameters are subject to method invocation conversions as necessary.
*
*
If the number of formal parameters required by the underlying constructor
* is 0, the supplied initargs array may be of length 0 or null.
*
*
If the constructor's declaring class is an inner class in a
* non-static context, the first argument to the constructor needs
* to be the enclosing instance; see The Java Language
* Specification, section 15.9.3.
*
*
If the required access and argument checks succeed and the
* instantiation will proceed, the constructor's declaring class
* is initialized if it has not already been initialized.
*
*
If the constructor completes normally, returns the newly
* created and initialized instance.
*
* @param initargs array of objects to be passed as arguments to
* the constructor call; values of primitive types are wrapped in
* a wrapper object of the appropriate type (e.g. a float
* in a {@link java.lang.Float Float})
*
* @return a new object created by calling the constructor
* this object represents
*
* @exception IllegalAccessException if this Constructor object
* enforces Java language access control and the underlying
* constructor is inaccessible.
* @exception IllegalArgumentException if the number of actual
* and formal parameters differ; if an unwrapping
* conversion for primitive arguments fails; or if,
* after possible unwrapping, a parameter value
* cannot be converted to the corresponding formal
* parameter type by a method invocation conversion; if
* this constructor pertains to an enum type.
* @exception InstantiationException if the class that declares the
* underlying constructor represents an abstract class.
* @exception InvocationTargetException if the underlying constructor
* throws an exception.
* @exception ExceptionInInitializerError if the initialization provoked
* by this method fails.
*/
@UnsafeNativeLong
public T newInstance(Object ... initargs)
throws InstantiationException, IllegalAccessException,
IllegalArgumentException, InvocationTargetException
{
return create(method, initargs);
}
@UnsafeNativeLong
private native T create(JavaScriptObject func, Object[] args)
/*-{
return func.apply(null, args);
}-*/;
/**
* Returns true if this constructor was declared to take
* a variable number of arguments; returns false
* otherwise.
*
* @return true if an only if this constructor was declared to
* take a variable number of arguments.
* @since 1.5
*/
public boolean isVarArgs() {
return (getModifiers() & Modifier.VARARGS) != 0;
}
/**
* Returns true if this constructor is a synthetic
* constructor; returns false otherwise.
*
* @return true if and only if this constructor is a synthetic
* constructor as defined by the Java Language Specification.
* @since 1.5
*/
public boolean isSynthetic() {
return Modifier.isSynthetic(getModifiers());
}
int getSlot() {
return slot;
}
String getSignature() {
return signature;
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
@Override
public A getAnnotation(Class annotationClass) {
if (annotationClass == null) throw new NullPointerException();
for (Annotation a : annos) {
if (a.annotationType() == annotationClass)
return (A)a;
}
return null;
}
/**
* @since 1.5
*/
@Override
public Annotation[] getDeclaredAnnotations() {
return annos;
}
/**
* Returns an array of arrays that represent the annotations on the formal
* parameters, in declaration order, of the method represented by
* this Constructor object. (Returns an array of length zero if the
* underlying method is parameterless. If the method has one or more
* parameters, a nested array of length zero is returned for each parameter
* with no annotations.) The annotation objects contained in the returned
* arrays are serializable. The caller of this method is free to modify
* the returned arrays; it will have no effect on the arrays returned to
* other callers.
*
* @return an array of arrays that represent the annotations on the formal
* parameters, in declaration order, of the method represented by this
* Constructor object
* @since 1.5
*/
public Annotation[][] getParameterAnnotations() {
Annotation[][] result = new Annotation[0][0];
return result;
}
}