| /* |
| * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.beans; |
| |
| import java.lang.ref.Reference; |
| import java.lang.ref.WeakReference; |
| import java.lang.reflect.Method; |
| import java.util.List; |
| import java.util.ArrayList; |
| |
| /** |
| * A MethodDescriptor describes a particular method that a Java Bean |
| * supports for external access from other components. |
| */ |
| |
| public class MethodDescriptor extends FeatureDescriptor { |
| |
| private Reference<Method> methodRef; |
| |
| private String[] paramNames; |
| |
| private List params; |
| |
| private ParameterDescriptor parameterDescriptors[]; |
| |
| /** |
| * Constructs a <code>MethodDescriptor</code> from a |
| * <code>Method</code>. |
| * |
| * @param method The low-level method information. |
| */ |
| public MethodDescriptor(Method method) { |
| this(method, null); |
| } |
| |
| |
| /** |
| * Constructs a <code>MethodDescriptor</code> from a |
| * <code>Method</code> providing descriptive information for each |
| * of the method's parameters. |
| * |
| * @param method The low-level method information. |
| * @param parameterDescriptors Descriptive information for each of the |
| * method's parameters. |
| */ |
| public MethodDescriptor(Method method, |
| ParameterDescriptor parameterDescriptors[]) { |
| setName(method.getName()); |
| setMethod(method); |
| this.parameterDescriptors = parameterDescriptors; |
| } |
| |
| /** |
| * Gets the method that this MethodDescriptor encapsualtes. |
| * |
| * @return The low-level description of the method |
| */ |
| public synchronized Method getMethod() { |
| Method method = getMethod0(); |
| if (method == null) { |
| Class cls = getClass0(); |
| String name = getName(); |
| if ((cls != null) && (name != null)) { |
| Class[] params = getParams(); |
| if (params == null) { |
| for (int i = 0; i < 3; i++) { |
| // Find methods for up to 2 params. We are guessing here. |
| // This block should never execute unless the classloader |
| // that loaded the argument classes disappears. |
| method = Introspector.findMethod(cls, name, i, null); |
| if (method != null) { |
| break; |
| } |
| } |
| } else { |
| method = Introspector.findMethod(cls, name, params.length, params); |
| } |
| setMethod(method); |
| } |
| } |
| return method; |
| } |
| |
| private synchronized void setMethod(Method method) { |
| if (method == null) { |
| return; |
| } |
| if (getClass0() == null) { |
| setClass0(method.getDeclaringClass()); |
| } |
| setParams(getParameterTypes(getClass0(), method)); |
| this.methodRef = getSoftReference(method); |
| } |
| |
| private Method getMethod0() { |
| return (this.methodRef != null) |
| ? this.methodRef.get() |
| : null; |
| } |
| |
| private synchronized void setParams(Class[] param) { |
| if (param == null) { |
| return; |
| } |
| paramNames = new String[param.length]; |
| params = new ArrayList(param.length); |
| for (int i = 0; i < param.length; i++) { |
| paramNames[i] = param[i].getName(); |
| params.add(new WeakReference(param[i])); |
| } |
| } |
| |
| // pp getParamNames used as an optimization to avoid method.getParameterTypes. |
| String[] getParamNames() { |
| return paramNames; |
| } |
| |
| private synchronized Class[] getParams() { |
| Class[] clss = new Class[params.size()]; |
| |
| for (int i = 0; i < params.size(); i++) { |
| Reference ref = (Reference)params.get(i); |
| Class cls = (Class)ref.get(); |
| if (cls == null) { |
| return null; |
| } else { |
| clss[i] = cls; |
| } |
| } |
| return clss; |
| } |
| |
| /** |
| * Gets the ParameterDescriptor for each of this MethodDescriptor's |
| * method's parameters. |
| * |
| * @return The locale-independent names of the parameters. May return |
| * a null array if the parameter names aren't known. |
| */ |
| public ParameterDescriptor[] getParameterDescriptors() { |
| return parameterDescriptors; |
| } |
| |
| /* |
| * Package-private constructor |
| * Merge two method descriptors. Where they conflict, give the |
| * second argument (y) priority over the first argument (x). |
| * @param x The first (lower priority) MethodDescriptor |
| * @param y The second (higher priority) MethodDescriptor |
| */ |
| |
| MethodDescriptor(MethodDescriptor x, MethodDescriptor y) { |
| super(x,y); |
| |
| methodRef = x.methodRef; |
| if (y.methodRef != null) { |
| methodRef = y.methodRef; |
| } |
| params = x.params; |
| if (y.params != null) { |
| params = y.params; |
| } |
| paramNames = x.paramNames; |
| if (y.paramNames != null) { |
| paramNames = y.paramNames; |
| } |
| |
| parameterDescriptors = x.parameterDescriptors; |
| if (y.parameterDescriptors != null) { |
| parameterDescriptors = y.parameterDescriptors; |
| } |
| } |
| |
| /* |
| * Package-private dup constructor |
| * This must isolate the new object from any changes to the old object. |
| */ |
| MethodDescriptor(MethodDescriptor old) { |
| super(old); |
| |
| methodRef = old.methodRef; |
| params = old.params; |
| paramNames = old.paramNames; |
| |
| if (old.parameterDescriptors != null) { |
| int len = old.parameterDescriptors.length; |
| parameterDescriptors = new ParameterDescriptor[len]; |
| for (int i = 0; i < len ; i++) { |
| parameterDescriptors[i] = new ParameterDescriptor(old.parameterDescriptors[i]); |
| } |
| } |
| } |
| |
| void appendTo(StringBuilder sb) { |
| appendTo(sb, "method", this.methodRef); |
| if (this.parameterDescriptors != null) { |
| sb.append("; parameterDescriptors={"); |
| for (ParameterDescriptor pd : this.parameterDescriptors) { |
| sb.append(pd).append(", "); |
| } |
| sb.setLength(sb.length() - 2); |
| sb.append("}"); |
| } |
| } |
| } |