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Java > Open Source Codes > org > python > core > PyGetSetDescr


1 package org.python.core;
2
3 import java.lang.reflect.InvocationTargetException JavaDoc;
4 import java.lang.reflect.Method JavaDoc;
5 import java.lang.reflect.Modifier JavaDoc;
6
7 public class PyGetSetDescr extends PyDescriptor {
8
9     private Method JavaDoc get_meth;
10     private Method JavaDoc set_meth;
11     private Class JavaDoc getset_type;
12
13     public PyGetSetDescr(PyType dtype, String JavaDoc name, Class JavaDoc c, String JavaDoc get, String JavaDoc set) {
14         this.name = name;
15         this.dtype = dtype;
16         try {
17             get_meth = c.getMethod(get, new Class JavaDoc[] {
18             });
19         } catch (NoSuchMethodException JavaDoc e) {
20             throw Py.SystemError("bogus getset spec");
21         }
22         if (Modifier.isStatic(get_meth.getModifiers()))
23             throw Py.SystemError("static getset not supported");
24         getset_type = get_meth.getReturnType();
25         if (set != null) {
26             try {
27                 set_meth = c.getMethod(set, new Class JavaDoc[] { getset_type });
28             } catch (NoSuchMethodException JavaDoc e) {
29                 throw Py.SystemError("bogus getset spec");
30             }
31             if (Modifier.isStatic(set_meth.getModifiers()))
32                 throw Py.SystemError("static getset not supported");
33
34         }
35     }
36
37     public PyGetSetDescr(String JavaDoc name, Class JavaDoc c, String JavaDoc get, String JavaDoc set) {
38         this(PyType.fromClass(c),name,c,get,set);
39     }
40     
41     public String JavaDoc toString() {
42         return "<attribute '"+name+"' of '"+dtype.fastGetName()+"' objects>";
43     }
44
45
46     /**
47      * @see org.python.core.PyObject#__get__(org.python.core.PyObject, org.python.core.PyObject)
48      */
49     public PyObject __get__(PyObject obj, PyObject type) {
50         try {
51             if (obj != null) {
52                 PyType objtype = obj.getType();
53                 if (objtype != dtype && !objtype.isSubType(dtype))
54                     throw get_wrongtype(objtype);
55                 Object JavaDoc v = get_meth.invoke(obj, new Object JavaDoc[0]);
56                 if (v == null) {
57                     obj.noAttributeError(name);
58                 }
59                 return Py.java2py(v);
60             }
61             return this;
62         } catch (IllegalArgumentException JavaDoc e) {
63             throw Py.JavaError(e);
64         } catch (IllegalAccessException JavaDoc e) {
65             throw Py.JavaError(e); // unexpected
66 } catch (InvocationTargetException JavaDoc e) {
67             throw Py.JavaError(e);
68         }
69     }
70
71     /**
72      * @see org.python.core.PyObject#__set__(org.python.core.PyObject, org.python.core.PyObject)
73      */
74     public void __set__(PyObject obj, PyObject value) {
75         try {
76             // obj != null
77 PyType objtype = obj.getType();
78             if (objtype != dtype && !objtype.isSubType(dtype))
79                 throw get_wrongtype(objtype);
80             Object JavaDoc converted = value.__tojava__(getset_type);
81             if (converted == Py.NoConversion) {
82                 throw Py.TypeError(""); // xxx
83 }
84             set_meth.invoke(obj, new Object JavaDoc[] { converted });
85
86         } catch (IllegalArgumentException JavaDoc e) {
87             throw Py.JavaError(e);
88         } catch (IllegalAccessException JavaDoc e) {
89             throw Py.JavaError(e); // unexpected
90 } catch (InvocationTargetException JavaDoc e) {
91             throw Py.JavaError(e);
92         }
93     }
94
95     /**
96      * @see org.python.core.PyObject#implementsDescrSet()
97      */
98     public boolean implementsDescrSet() {
99         return set_meth != null;
100     }
101
102     /**
103      * @see org.python.core.PyObject#isDataDescr()
104      */
105     public boolean isDataDescr() {
106         return true;
107     }
108
109 }
110
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