ClassLoaderUtil xref
1 /**
2 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
3 */
4 package net.sourceforge.pmd.dcd;
5
6 import java.lang.reflect.Constructor;
7 import java.lang.reflect.Field;
8 import java.lang.reflect.Method;
9
10 /**
11 * ClassLoader utilities. Useful for extracting additional details from a class
12 * hierarchy beyond the basic standard Java Reflection APIs.
13 */
14 public class ClassLoaderUtil {
15
16 public static final String CLINIT = "<clinit>";
17
18 public static final String INIT = "<init>";
19
20 public static String fromInternalForm(String internalForm) {
21 return internalForm.replace('/', '.');
22 }
23
24 public static String toInternalForm(String internalForm) {
25 return internalForm.replace('.', '/');
26 }
27
28 public static Class<?> getClass(String name) {
29 try {
30 return ClassLoaderUtil.class.getClassLoader().loadClass(name);
31 } catch (ClassNotFoundException e) {
32 throw new RuntimeException(e);
33 }
34 }
35
36 public static Field getField(Class<?> type, String name) {
37 try {
38 return myGetField(type, name);
39 } catch (NoSuchFieldException e) {
40 throw new RuntimeException(e);
41 }
42 }
43
44 private static Field myGetField(Class<?> type, String name) throws NoSuchFieldException {
45 // Scan the type hierarchy just like Class.getField(String) using
46 // Class.getDeclaredField(String)
47 try {
48 return type.getDeclaredField(name);
49 } catch (NoSuchFieldException e) {
50 // Try the super interfaces
51 for (Class<?> superInterface : type.getInterfaces()) {
52 try {
53 return myGetField(superInterface, name);
54 } catch (NoSuchFieldException e2) {
55 // Okay
56 }
57 }
58 // Try the super classes
59 if (type.getSuperclass() != null) {
60 return myGetField(type.getSuperclass(), name);
61 } else {
62 throw new NoSuchFieldException(type.getName() + "." + name);
63 }
64 }
65 }
66
67 public static Method getMethod(Class<?> type, String name, Class<?>... parameterTypes) {
68 try {
69 return myGetMethod(type, name, parameterTypes);
70 } catch (NoSuchMethodException e) {
71 throw new RuntimeException(e);
72 }
73 }
74
75 private static Method myGetMethod(Class<?> type, String name, Class<?>... parameterTypes)
76 throws NoSuchMethodException {
77 // Scan the type hierarchy just like Class.getMethod(String, Class[])
78 // using Class.getDeclaredMethod(String, Class[])
79 // System.out.println("type: " + type);
80 // System.out.println("name: " + name);
81 // System.out
82 // .println("parameterTypes: " + Arrays.toString(parameterTypes));
83 try {
84 // System.out.println("Checking getDeclaredMethod");
85 // for (Method m : type.getDeclaredMethods()) {
86 // System.out.println("\t" + m);
87 // }
88 return type.getDeclaredMethod(name, parameterTypes);
89 } catch (NoSuchMethodException e) {
90 try {
91 // Try the super classes
92 if (type.getSuperclass() != null) {
93 // System.out.println("Checking super: "
94 // + type.getSuperclass());
95 return myGetMethod(type.getSuperclass(), name, parameterTypes);
96 }
97 } catch (NoSuchMethodException e2) {
98 // Okay
99 }
100 // Try the super interfaces
101 for (Class<?> superInterface : type.getInterfaces()) {
102 try {
103 // System.out.println("Checking super interface: "
104 // + superInterface);
105 return myGetMethod(superInterface, name, parameterTypes);
106 } catch (NoSuchMethodException e3) {
107 // Okay
108 }
109 }
110 throw new NoSuchMethodException(type.getName() + '.' + getMethodSignature(name, parameterTypes));
111 }
112 }
113
114 public static Constructor<?> getConstructor(Class<?> type, String name, Class<?>... parameterTypes) {
115 try {
116 return type.getDeclaredConstructor(parameterTypes);
117 } catch (NoSuchMethodException e) {
118 throw new RuntimeException(e);
119 }
120 }
121
122 public static String getMethodSignature(String name, Class<?>... parameterTypes) {
123 StringBuilder builder = new StringBuilder(name);
124 if (!(name.equals(CLINIT) || name.equals(INIT))) {
125 builder.append('(');
126 if (parameterTypes != null && parameterTypes.length > 0) {
127 builder.append(parameterTypes[0].getName());
128 for (int i = 1; i < parameterTypes.length; i++) {
129 builder.append(", ").append(parameterTypes[i].getName());
130 }
131 }
132 builder.append(')');
133 }
134 return builder.toString();
135 }
136
137 public static Class<?>[] getParameterTypes(String... parameterTypeNames) {
138 Class<?>[] parameterTypes = new Class[parameterTypeNames.length];
139 for (int i = 0; i < parameterTypeNames.length; i++) {
140 parameterTypes[i] = getClass(parameterTypeNames[i]);
141 }
142 return parameterTypes;
143 }
144
145 public static boolean isOverridenMethod(Class<?> clazz, Method method, boolean checkThisClass) {
146 try {
147 if (checkThisClass) {
148 clazz.getDeclaredMethod(method.getName(), method.getParameterTypes());
149 return true;
150 }
151 } catch (NoSuchMethodException e) {
152 }
153 // Check super class
154 if (clazz.getSuperclass() != null) {
155 if (isOverridenMethod(clazz.getSuperclass(), method, true)) {
156 return true;
157 }
158 }
159 // Check interfaces
160 for (Class<?> anInterface : clazz.getInterfaces()) {
161 if (isOverridenMethod(anInterface, method, true)) {
162 return true;
163 }
164 }
165 return false;
166 }
167 }