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Java > Open Source Codes > org > apache > commons > discovery > tools > ClassUtils


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61
62 package org.apache.commons.discovery.tools;
63
64 import java.lang.reflect.Method JavaDoc;
65 import java.lang.reflect.Modifier JavaDoc;
66
67 import org.apache.commons.discovery.log.DiscoveryLogFactory;
68 import org.apache.commons.logging.Log;
69
70
71 /**
72  * @author Richard A. Sitze
73  */
74 public class ClassUtils {
75     private static Log log = DiscoveryLogFactory.newLog(ClassUtils.class);
76     public static void setLog(Log _log) {
77         log = _log;
78     }
79
80     /**
81      * Get package name.
82      * Not all class loaders 'keep' package information,
83      * in which case Class.getPackage() returns null.
84      * This means that calling Class.getPackage().getName()
85      * is unreliable at best.
86      */
87     public static String JavaDoc getPackageName(Class JavaDoc clazz) {
88         Package JavaDoc clazzPackage = clazz.getPackage();
89         String JavaDoc packageName;
90         if (clazzPackage != null) {
91             packageName = clazzPackage.getName();
92         } else {
93             String JavaDoc clazzName = clazz.getName();
94             packageName = new String JavaDoc(clazzName.toCharArray(), 0, clazzName.lastIndexOf('.'));
95         }
96         return packageName;
97     }
98     
99     /**
100      * @return Method 'public static returnType methodName(paramTypes)',
101      * if found to be <strong>directly</strong> implemented by clazz.
102      */
103     public static Method JavaDoc findPublicStaticMethod(Class JavaDoc clazz,
104                                                 Class JavaDoc returnType,
105                                                 String JavaDoc methodName,
106                                                 Class JavaDoc[] paramTypes) {
107         boolean problem = false;
108         Method JavaDoc method = null;
109
110         // verify '<methodName>(<paramTypes>)' is directly in class.
111 try {
112             method = clazz.getDeclaredMethod(methodName, paramTypes);
113         } catch(NoSuchMethodException JavaDoc e) {
114             problem = true;
115             log.debug("Class " + clazz.getName() + ": missing method '" + methodName + "(...)", e);
116         }
117         
118         // verify 'public static <returnType>'
119 if (!problem &&
120             !(Modifier.isPublic(method.getModifiers()) &&
121               Modifier.isStatic(method.getModifiers()) &&
122               method.getReturnType() == returnType)) {
123             if (log.isDebugEnabled()) {
124                 if (!Modifier.isPublic(method.getModifiers())) {
125                     log.debug(methodName + "() is not public");
126                 }
127                 if (!Modifier.isStatic(method.getModifiers())) {
128                     log.debug(methodName + "() is not static");
129                 }
130                 if (method.getReturnType() != returnType) {
131                     log.debug("Method returns: " + method.getReturnType().getName() + "@@" + method.getReturnType().getClassLoader());
132                     log.debug("Should return: " + returnType.getName() + "@@" + returnType.getClassLoader());
133                 }
134             }
135             problem = true;
136             method = null;
137         }
138         
139         return method;
140     }
141 }
142
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