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1
33 package net.sf.jga.fn.property;
34
35 import java.lang.reflect.InvocationTargetException  ;
36 import java.lang.reflect.Method ;
37 import java.text.MessageFormat ;
38 import net.sf.jga.fn.BinaryFunctor;
39 import net.sf.jga.fn.EvaluationException;
40 import net.sf.jga.fn.UnaryFunctor;
41 import net.sf.jga.fn.adaptor.ChainBinary;
42 import net.sf.jga.fn.adaptor.ChainUnary;
43
44
56
57 public class InvokeNoArgMethod<T,R> extends UnaryFunctor<T,R> {
58
59 static final long serialVersionUID = -2651164047444243205L;
60
61 private String _methName;
63
64 private Class <T> _objclass;
66
67 private transient Method _meth;
69
70
74
75 public InvokeNoArgMethod(Class <T> objclass, String methName) {
76 if (methName == null || methName.length() == 0) {
77 String msg = "Must supply method name";
78 throw new IllegalArgumentException (msg);
79 }
80
81 if (objclass == null) {
82 String msg = "Must supply object class";
83 throw new IllegalArgumentException (msg);
84 }
85
86 _methName = methName;
87 _objclass = objclass;
88
89 try {
90 _meth = objclass.getMethod(_methName, new Class [0]);
91 }
92 catch (NoSuchMethodException x) {
93 String msg = "No such method: "+x.getMessage();
94 IllegalArgumentException iax = new IllegalArgumentException (msg);
95 iax.initCause(x);
96 throw iax;
97 }
98 }
99
100
105
106 public InvokeNoArgMethod(Class <T> objClass, Method method) {
107 if (method == null) {
108 String msg = "Must supply method";
109 throw new IllegalArgumentException (msg);
110 }
111
112 if (objClass == null) {
113 String msg = "Must supply object class";
114 throw new IllegalArgumentException (msg);
115 }
116
117 if (method.getParameterTypes().length != 0) {
118 String msg = "Method {0} takes arguments";
119 Object [] args = { method.getName() };
120 throw new IllegalArgumentException (MessageFormat.format(msg, args));
121 }
122
123 if (!method.getDeclaringClass().isAssignableFrom(objClass)) {
124 String msg = "Method {0} not defined for class {1}";
125 Object [] args = { method.getName(), objClass.getName() };
126 throw new IllegalArgumentException (MessageFormat.format(msg, args));
127 }
128
129 _objclass = objClass;
130 _meth = method;
131 _methName = method.getName();
132 }
133
134
137 public String getMethodName() {
138 return _methName;
139 }
140
141
144 public Class <R> getReturnType() {
145 return (Class <R>) _meth.getReturnType();
146 }
147
148
151 public synchronized Method getMethod() throws NoSuchMethodException {
152 if (_meth == null)
153 _meth = _objclass.getMethod(_methName, new Class [0]);
154
155 return _meth;
156 }
157
158
160
166 public R fn(T obj) {
167 try {
168 return (R) getMethod().invoke(obj, new Object [0]);
172 }
173 catch (NoSuchMethodException x) {
174 String msg = "No method {0} for class {1} that takes no arguments";
175 Object [] args = new Object []{_methName, _objclass.getName()};
176 throw new EvaluationException(MessageFormat.format(msg,args), x);
177 }
178 catch (ClassCastException x) {
179 String msg = "ClassCastException: " +_objclass +"." +_methName +"()";
180 throw new EvaluationException(msg, x);
181 }
182 catch (IllegalAccessException x) {
183 String msg = _objclass +"." +_methName +" is not accessible";
184 throw new EvaluationException(msg, x);
185 }
186 catch (InvocationTargetException x) {
187 String xmsg = x.getMessage();
188 String msg = "InvocationException: " +_objclass +"." +_methName
189 +"()"+(xmsg != null ? (":"+xmsg) : "");
190 throw new EvaluationException(msg, x);
191 }
192 }
193
194
195
199 public void accept(net.sf.jga.fn.Visitor v) {
200 if (v instanceof InvokeNoArgMethod.Visitor)
201 ((InvokeNoArgMethod.Visitor)v).visit(this);
202 else
203 v.visit(this);
204 }
205
206
208 public String toString() {
209 return "InvokeNoArgMethod("+_meth+")";
210 }
211
212
214
218 public interface Visitor extends net.sf.jga.fn.Visitor {
219 public void visit(InvokeNoArgMethod host);
220 }
221 }
222 |
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