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Diffstat (limited to 'libjava/java/lang/reflect/Constructor.java')
| -rw-r--r-- | libjava/java/lang/reflect/Constructor.java | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/libjava/java/lang/reflect/Constructor.java b/libjava/java/lang/reflect/Constructor.java new file mode 100644 index 000000000..adebc600a --- /dev/null +++ b/libjava/java/lang/reflect/Constructor.java @@ -0,0 +1,424 @@ +/* java.lang.reflect.Constructor - reflection of Java constructors + Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007 + Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.lang.reflect; + +import gnu.java.lang.reflect.MethodSignatureParser; +import java.lang.annotation.Annotation; + +/** + * The Constructor class represents a constructor of a class. It also allows + * dynamic creation of an object, via reflection. Invocation on Constructor + * objects knows how to do widening conversions, but throws + * {@link IllegalArgumentException} if a narrowing conversion would be + * necessary. You can query for information on this Constructor regardless + * of location, but construction access may be limited by Java language + * access controls. If you can't do it in the compiler, you can't normally + * do it here either.<p> + * + * <B>Note:</B> This class returns and accepts types as Classes, even + * primitive types; there are Class types defined that represent each + * different primitive type. They are <code>java.lang.Boolean.TYPE, + * java.lang.Byte.TYPE,</code>, also available as <code>boolean.class, + * byte.class</code>, etc. These are not to be confused with the + * classes <code>java.lang.Boolean, java.lang.Byte</code>, etc., which are + * real classes.<p> + * + * Also note that this is not a serializable class. It is entirely feasible + * to make it serializable using the Externalizable interface, but this is + * on Sun, not me. + * + * @author John Keiser + * @author Eric Blake <ebb9@email.byu.edu> + * @author Tom Tromey <tromey@redhat.com> + * @see Member + * @see Class + * @see java.lang.Class#getConstructor(Class[]) + * @see java.lang.Class#getDeclaredConstructor(Class[]) + * @see java.lang.Class#getConstructors() + * @see java.lang.Class#getDeclaredConstructors() + * @since 1.1 + * @status updated to 1.4 + */ +public final class Constructor<T> extends AccessibleObject + implements Member, GenericDeclaration +{ + private static final int CONSTRUCTOR_MODIFIERS + = Modifier.PRIVATE | Modifier.PROTECTED | Modifier.PUBLIC; + + /** + * This class is uninstantiable except from native code. + */ + private Constructor () + { + } + + /** + * Gets the class that declared this constructor. + * @return the class that declared this member + */ + public Class<T> getDeclaringClass () + { + return declaringClass; + } + + /** + * Gets the name of this constructor (the non-qualified name of the class + * it was declared in). + * @return the name of this constructor + */ + public String getName() + { + return declaringClass.getName(); + } + + /** + * Return the raw modifiers for this constructor. In particular + * this will include the synthetic and varargs bits. + * @return the constructor's modifiers + */ + private native int getModifiersInternal(); + + /** + * Gets the modifiers this constructor uses. Use the <code>Modifier</code> + * class to interpret the values. A constructor can only have a subset of the + * following modifiers: public, private, protected. + * + * @return an integer representing the modifiers to this Member + * @see Modifier + */ + public int getModifiers () + { + return getModifiersInternal() & CONSTRUCTOR_MODIFIERS; + } + + /** + * Return true if this constructor is synthetic, false otherwise. + * A synthetic member is one which is created by the compiler, + * and which does not appear in the user's source code. + * @since 1.5 + */ + public boolean isSynthetic() + { + return (getModifiersInternal() & Modifier.SYNTHETIC) != 0; + } + + /** + * Return true if this is a varargs constructor, that is if + * the constructor takes a variable number of arguments. + * @since 1.5 + */ + public boolean isVarArgs() + { + return (getModifiersInternal() & Modifier.VARARGS) != 0; + } + + /** + * Get the parameter list for this constructor, in declaration order. If the + * constructor takes no parameters, returns a 0-length array (not null). + * + * @return a list of the types of the constructor's parameters + */ + public Class<?>[] getParameterTypes () + { + if (parameter_types == null) + getType (); + return (Class<?>[]) parameter_types.clone(); + } + + /** + * Get the exception types this constructor says it throws, in no particular + * order. If the constructor has no throws clause, returns a 0-length array + * (not null). + * + * @return a list of the types in the constructor's throws clause + */ + public Class<?>[] getExceptionTypes () + { + if (exception_types == null) + getType(); + return (Class<?>[]) exception_types.clone(); + } + + /** + * Compare two objects to see if they are semantically equivalent. + * Two Constructors are semantically equivalent if they have the same + * declaring class and the same parameter list. + * + * @param o the object to compare to + * @return <code>true</code> if they are equal; <code>false</code> if not. + */ + public boolean equals (Object obj) + { + if (! (obj instanceof Constructor)) + return false; + Constructor c = (Constructor) obj; + return declaringClass == c.declaringClass && offset == c.offset; + } + + /** + * Get the hash code for the Constructor. The Constructor hash code is the + * hash code of the declaring class's name. + * + * @return the hash code for the object + */ + public int hashCode () + { + return declaringClass.getName().hashCode(); + } + + /** + * Get a String representation of the Constructor. A Constructor's String + * representation is "<modifier> <classname>(<paramtypes>) + * throws <exceptions>", where everything after ')' is omitted if + * there are no exceptions.<br> Example: + * <code>public java.io.FileInputStream(java.lang.Runnable) + * throws java.io.FileNotFoundException</code> + * + * @return the String representation of the Constructor + */ + public String toString() + { + if (parameter_types == null) + getType (); + StringBuffer b = new StringBuffer (); + int mods = getModifiers(); + if (mods != 0) + { + Modifier.toString(mods, b); + b.append(" "); + } + Method.appendClassName (b, declaringClass); + b.append("("); + for (int i = 0; i < parameter_types.length; ++i) + { + Method.appendClassName (b, parameter_types[i]); + if (i < parameter_types.length - 1) + b.append(","); + } + b.append(")"); + return b.toString(); + } + + static <X extends GenericDeclaration> + void addTypeParameters(StringBuilder sb, TypeVariable<X>[] typeArgs) + { + if (typeArgs.length == 0) + return; + sb.append('<'); + for (int i = 0; i < typeArgs.length; ++i) + { + if (i > 0) + sb.append(','); + sb.append(typeArgs[i]); + } + sb.append("> "); + } + + public String toGenericString() + { + StringBuilder sb = new StringBuilder(128); + Modifier.toString(getModifiers(), sb).append(' '); + addTypeParameters(sb, getTypeParameters()); + sb.append(getDeclaringClass().getName()).append('('); + Type[] types = getGenericParameterTypes(); + if (types.length > 0) + { + sb.append(types[0]); + for (int i = 1; i < types.length; ++i) + sb.append(',').append(types[i]); + } + sb.append(')'); + types = getGenericExceptionTypes(); + if (types.length > 0) + { + sb.append(" throws ").append(types[0]); + for (int i = 1; i < types.length; i++) + sb.append(',').append(types[i]); + } + return sb.toString(); + } + + /** + * Create a new instance by invoking the constructor. Arguments are + * automatically unwrapped and widened, if needed.<p> + * + * If this class is abstract, you will get an + * <code>InstantiationException</code>. If the constructor takes 0 + * arguments, you may use null or a 0-length array for <code>args</code>.<p> + * + * If this Constructor enforces access control, your runtime context is + * evaluated, and you may have an <code>IllegalAccessException</code> if + * you could not create this object in similar compiled code. If the class + * is uninitialized, you trigger class initialization, which may end in a + * <code>ExceptionInInitializerError</code>.<p> + * + * Then, the constructor is invoked. If it completes normally, the return + * value will be the new object. If it completes abruptly, the exception is + * wrapped in an <code>InvocationTargetException</code>. + * + * @param args the arguments to the constructor + * @return the newly created object + * @throws IllegalAccessException if the constructor could not normally be + * called by the Java code (i.e. it is not public) + * @throws IllegalArgumentException if the number of arguments is incorrect; + * or if the arguments types are wrong even with a widening + * conversion + * @throws InstantiationException if the class is abstract + * @throws InvocationTargetException if the constructor throws an exception + * @throws ExceptionInInitializerError if construction triggered class + * initialization, which then failed + */ + public native T newInstance (Object... args) + throws InstantiationException, IllegalAccessException, + IllegalArgumentException, InvocationTargetException; + + /** + * Returns an array of <code>TypeVariable</code> objects that represents + * the type variables declared by this constructor, in declaration order. + * An array of size zero is returned if this constructor has no type + * variables. + * + * @return the type variables associated with this constructor. + * @throws GenericSignatureFormatError if the generic signature does + * not conform to the format specified in the Virtual Machine + * specification, version 3. + * @since 1.5 + */ + public TypeVariable<Constructor<T>>[] getTypeParameters() + { + String sig = getSignature(); + if (sig == null) + return new TypeVariable[0]; + MethodSignatureParser p = new MethodSignatureParser(this, sig); + return p.getTypeParameters(); + } + + /** + * Return the String in the Signature attribute for this constructor. If there + * is no Signature attribute, return null. + */ + private native String getSignature(); + + /** + * Returns an array of <code>Type</code> objects that represents + * the exception types declared by this constructor, in declaration order. + * An array of size zero is returned if this constructor declares no + * exceptions. + * + * @return the exception types declared by this constructor. + * @throws GenericSignatureFormatError if the generic signature does + * not conform to the format specified in the Virtual Machine + * specification, version 3. + * @since 1.5 + */ + public Type[] getGenericExceptionTypes() + { + String sig = getSignature(); + if (sig == null) + return getExceptionTypes(); + MethodSignatureParser p = new MethodSignatureParser(this, sig); + return p.getGenericExceptionTypes(); + } + + /** + * Returns an array of <code>Type</code> objects that represents + * the parameter list for this constructor, in declaration order. + * An array of size zero is returned if this constructor takes no + * parameters. + * + * @return a list of the types of the constructor's parameters + * @throws GenericSignatureFormatError if the generic signature does + * not conform to the format specified in the Virtual Machine + * specification, version 3. + * @since 1.5 + */ + public Type[] getGenericParameterTypes() + { + String sig = getSignature(); + if (sig == null) + return getParameterTypes(); + MethodSignatureParser p = new MethodSignatureParser(this, sig); + return p.getGenericParameterTypes(); + } + + public <T extends Annotation> T getAnnotation(Class<T> annoClass) + { + Annotation[] annos = getDeclaredAnnotations(); + for (int i = 0; i < annos.length; ++i) + if (annos[i].annotationType() == annoClass) + return (T) annos[i]; + return null; + } + + public Annotation[] getDeclaredAnnotations() + { + Annotation[] result = getDeclaredAnnotationsInternal(); + if (result == null) + result = new Annotation[0]; + return result; + } + + public Annotation[][] getParameterAnnotations() + { + // FIXME: should check that we have the right number + // of parameters ...? + Annotation[][] result = getParameterAnnotationsInternal(); + if (result == null) + result = new Annotation[0][0]; + return result; + } + + private native Annotation[] getDeclaredAnnotationsInternal(); + private native Annotation[][] getParameterAnnotationsInternal(); + + // Update cached values from method descriptor in class. + private native void getType (); + + // Declaring class. + private Class<T> declaringClass; + + // Exception types. + private Class[] exception_types; + // Parameter types. + private Class[] parameter_types; + + // Offset in bytes from the start of declaringClass's methods array. + private int offset; +} |