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Diffstat (limited to 'libjava/java/lang/reflect/Method.java')
| -rw-r--r-- | libjava/java/lang/reflect/Method.java | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/libjava/java/lang/reflect/Method.java b/libjava/java/lang/reflect/Method.java new file mode 100644 index 000000000..878210abb --- /dev/null +++ b/libjava/java/lang/reflect/Method.java @@ -0,0 +1,501 @@ +// Method.java - Represent method of class or interface. + +/* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2006, 2007 Free Software Foundation + + This file is part of libgcj. + +This software is copyrighted work licensed under the terms of the +Libgcj License. Please consult the file "LIBGCJ_LICENSE" for +details. */ + +package java.lang.reflect; + +import gnu.gcj.RawData; +import gnu.java.lang.reflect.MethodSignatureParser; +import java.lang.annotation.Annotation; + +/** + * The Method class represents a member method of a class. It also allows + * dynamic invocation, via reflection. This works for both static and + * instance methods. Invocation on Method 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 Method regardless of location, but invocation 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#getMethod(String,Class[]) + * @see java.lang.Class#getDeclaredMethod(String,Class[]) + * @see java.lang.Class#getMethods() + * @see java.lang.Class#getDeclaredMethods() + * @since 1.1 + * @status updated to 1.4 + */ +public final class Method + extends AccessibleObject implements Member, GenericDeclaration +{ + static final int METHOD_MODIFIERS + = Modifier.ABSTRACT | Modifier.FINAL | Modifier.NATIVE + | Modifier.PRIVATE | Modifier.PROTECTED | Modifier.PUBLIC + | Modifier.STATIC | Modifier.STRICT | Modifier.SYNCHRONIZED; + + /** + * This class is uninstantiable. + */ + private Method () + { + } + + /** + * Gets the class that declared this method, or the class where this method + * is a non-inherited member. + * @return the class that declared this member + */ + public Class<?> getDeclaringClass() + { + return declaringClass; + } + + /** + * Gets the name of this method. + * @return the name of this method + */ + public native String getName (); + + /** + * Return the raw modifiers for this method. + * @return the method's modifiers + */ + private native int getModifiersInternal(); + + /** + * Gets the modifiers this method uses. Use the <code>Modifier</code> + * class to interpret the values. A method can only have a subset of the + * following modifiers: public, private, protected, abstract, static, + * final, synchronized, native, and strictfp. + * + * @return an integer representing the modifiers to this Member + * @see Modifier + */ + public int getModifiers() + { + return getModifiersInternal() & METHOD_MODIFIERS; + } + + /** + * Return true if this method is a bridge method. A bridge method + * is generated by the compiler in some situations involving + * generics and inheritance. + * @since 1.5 + */ + public boolean isBridge() + { + return (getModifiersInternal() & Modifier.BRIDGE) != 0; + } + + /** + * Return true if this method is synthetic, false otherwise. + * @since 1.5 + */ + public boolean isSynthetic() + { + return (getModifiersInternal() & Modifier.SYNTHETIC) != 0; + } + + /** + * Return true if this is a varargs method, that is if + * the method takes a variable number of arguments. + * @since 1.5 + */ + public boolean isVarArgs() + { + return (getModifiersInternal() & Modifier.VARARGS) != 0; + } + + /** + * Gets the return type of this method. + * @return the type of this method + */ + public Class<?> getReturnType () + { + if (return_type == null) + getType(); + return return_type; + } + + /** + * Get the parameter list for this method, in declaration order. If the + * method takes no parameters, returns a 0-length array (not null). + * + * @return a list of the types of the method's parameters + */ + public Class<?>[] getParameterTypes () + { + if (parameter_types == null) + getType(); + return (Class<?>[]) parameter_types.clone(); + } + + // Just like getParameterTypes, but don't clone the array. + // Package private for use by VMProxy. + final Class<?>[] internalGetParameterTypes () + { + if (parameter_types == null) + getType(); + return (Class<?>[]) parameter_types; + } + + /** + * Get the exception types this method says it throws, in no particular + * order. If the method has no throws clause, returns a 0-length array + * (not null). + * + * @return a list of the types in the method's throws clause + */ + public Class<?>[] getExceptionTypes () + { + if (exception_types == null) + getType(); + return (Class<?>[]) exception_types.clone(); + } + + // Just like getExceptionTypes, but don't clone the array. + // Package private for use by VMProxy. + final Class<?>[] internalGetExceptionTypes () + { + if (exception_types == null) + getType(); + return (Class<?>[]) exception_types; + } + + /** + * Compare two objects to see if they are semantically equivalent. + * Two Methods are semantically equivalent if they have the same declaring + * class, name, and parameter list. This ignores different exception + * clauses or return types. + * + * @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 Method)) + return false; + Method m = (Method) obj; + return declaringClass == m.declaringClass && offset == m.offset; + } + + /** + * Get the hash code for the Method. The Method hash code is the hash code + * of its name XOR'd with the hash code of its class name. + * + * @return the hash code for the object + */ + public int hashCode() + { + return getDeclaringClass().getName().hashCode() ^ getName().hashCode(); + } + + /** + * Get a String representation of the Method. A Method's String + * representation is "<modifiers> <returntype> + * <methodname>(<paramtypes>) throws <exceptions>", where + * everything after ')' is omitted if there are no exceptions.<br> Example: + * <code>public static int run(java.lang.Runnable,int)</code> + * + * @return the String representation of the Method + */ + public String toString() + { + if (parameter_types == null) + getType (); + + StringBuffer b = new StringBuffer (); + int mods = getModifiers(); + if (mods != 0) + { + Modifier.toString(mods, b); + b.append(" "); + } + appendClassName (b, return_type); + b.append(" "); + appendClassName (b, declaringClass); + b.append("."); + b.append(getName()); + b.append("("); + for (int i = 0; i < parameter_types.length; ++i) + { + appendClassName (b, parameter_types[i]); + if (i < parameter_types.length - 1) + b.append(","); + } + b.append(")"); + if (exception_types.length > 0) + { + b.append(" throws "); + for (int i = 0; i < exception_types.length; ++i) + { + appendClassName (b, exception_types[i]); + if (i < exception_types.length - 1) + b.append(","); + } + } + return b.toString(); + } + + public String toGenericString() + { + // 128 is a reasonable buffer initial size for constructor + StringBuilder sb = new StringBuilder(128); + Modifier.toString(getModifiers(), sb).append(' '); + Constructor.addTypeParameters(sb, getTypeParameters()); + sb.append(getGenericReturnType()).append(' '); + sb.append(getDeclaringClass().getName()).append('.'); + sb.append(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(); + } + + /** + * Invoke the method. Arguments are automatically unwrapped and widened, + * and the result is automatically wrapped, if needed.<p> + * + * If the method is static, <code>o</code> will be ignored. Otherwise, + * the method uses dynamic lookup as described in JLS 15.12.4.4. You cannot + * mimic the behavior of nonvirtual lookup (as in super.foo()). This means + * you will get a <code>NullPointerException</code> if <code>o</code> is + * null, and an <code>IllegalArgumentException</code> if it is incompatible + * with the declaring class of the method. If the method takes 0 arguments, + * you may use null or a 0-length array for <code>args</code>.<p> + * + * Next, if this Method enforces access control, your runtime context is + * evaluated, and you may have an <code>IllegalAccessException</code> if + * you could not acces this method in similar compiled code. If the method + * is static, and its class is uninitialized, you trigger class + * initialization, which may end in a + * <code>ExceptionInInitializerError</code>.<p> + * + * Finally, the method is invoked. If it completes normally, the return value + * will be null for a void method, a wrapped object for a primitive return + * method, or the actual return of an Object method. If it completes + * abruptly, the exception is wrapped in an + * <code>InvocationTargetException</code>. + * + * @param o the object to invoke the method on + * @param args the arguments to the method + * @return the return value of the method, wrapped in the appropriate + * wrapper if it is primitive + * @throws IllegalAccessException if the method could not normally be called + * by the Java code (i.e. it is not public) + * @throws IllegalArgumentException if the number of arguments is incorrect; + * if the arguments types are wrong even with a widening conversion; + * or if <code>o</code> is not an instance of the class or interface + * declaring this method + * @throws InvocationTargetException if the method throws an exception + * @throws NullPointerException if <code>o</code> is null and this field + * requires an instance + * @throws ExceptionInInitializerError if accessing a static method triggered + * class initialization, which then failed + */ + public native Object invoke (Object obj, Object... args) + throws 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 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 TypeVariable<Method>[] 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 method. 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 method, in declaration order. + * An array of size zero is returned if this method declares no + * exceptions. + * + * @return the exception types declared by this method. + * @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 method, in declaration order. + * An array of size zero is returned if this method takes no + * parameters. + * + * @return a list of the types of the method'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(); + } + + /** + * Returns the return type of this method. + * + * @return the return type of this method + * @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 getGenericReturnType() + { + String sig = getSignature(); + if (sig == null) + return getReturnType(); + MethodSignatureParser p = new MethodSignatureParser(this, sig); + return p.getGenericReturnType(); + } + + /** + * If this method is an annotation method, returns the default + * value for the method. If there is no default value, or if the + * method is not a member of an annotation type, returns null. + * Primitive types are wrapped. + * + * @throws TypeNotPresentException if the method returns a Class, + * and the class cannot be found + * + * @since 1.5 + */ + public native Object getDefaultValue(); + + 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(); + + private native void getType (); + + // Append a class name to a string buffer. We try to print the + // fully-qualified name, the way that a Java programmer would expect + // it to be written. Weirdly, Class has no appropriate method for + // this. + static void appendClassName (StringBuffer buf, Class k) + { + if (k.isArray ()) + { + appendClassName (buf, k.getComponentType ()); + buf.append ("[]"); + } + else + { + // This is correct for primitive and reference types. Really + // we'd like `Main$Inner' to be printed as `Main.Inner', I + // think, but that is a pain. + buf.append (k.getName ()); + } + } + + // Declaring class. + private Class declaringClass; + + // Exception types. + Class[] exception_types; + // Name cache. (Initially null.) + private String name; + // Parameter types. + Class[] parameter_types; + // Return type. + Class return_type; + + // Offset in bytes from the start of declaringClass's methods array. + private int offset; +} |