|
1 package com.thoughtworks.xstream.converters.reflection;
2
3 import java.lang.reflect.Field  ;
4 import java.util.Iterator ;
5 import java.util.Map ;
6 import java.util.TreeMap ;
7
8 public class FieldDictionary {
9
10 private static final Map keyedByFieldNameCache = new TreeMap ();
11 private static final Map keyedByFieldKeyCache = new TreeMap ();
12
13 public Iterator serializableFieldsFor(Class cls) {
14 return buildMap(cls, true).values().iterator();
15 }
16
17 public Field field(Class cls, String name, Class definedIn) {
18 Map fields = buildMap(cls, definedIn != null);
19 Field field = (Field ) fields.get(definedIn != null ? (Object ) new FieldKey(name, definedIn) : (Object ) name);
20 if (field == null) {
21 throw new ObjectAccessException("No such field " + cls.getName() + "." + name);
22 } else {
23 return field;
24 }
25 }
26
27 private Map buildMap(Class cls, boolean tupleKeyed) {
28 final String clsName = cls.getName();
29 if (!keyedByFieldNameCache.containsKey(clsName)) {
30 final Map keyedByFieldName = new TreeMap ();
31 final Map keyedByFieldKey = new TreeMap ();
32 while (!Object .class.equals(cls)) {
33 Field [] fields = cls.getDeclaredFields();
34 for (int i = 0; i < fields.length; i++) {
35 Field field = fields[i];
36 if (field.getName().startsWith("this$")) {
37 continue;
38 }
39 field.setAccessible(true);
40 if (!keyedByFieldName.containsKey(field.getName())) {
41 keyedByFieldName.put(field.getName(), field);
42 }
43 keyedByFieldKey.put(new FieldKey(field.getName(), field.getDeclaringClass()), field);
44 }
45 cls = cls.getSuperclass();
46 }
47 keyedByFieldNameCache.put(clsName, keyedByFieldName);
48 keyedByFieldKeyCache.put(clsName, keyedByFieldKey);
49 }
50 return (Map ) (tupleKeyed ? keyedByFieldKeyCache.get(clsName) : keyedByFieldNameCache.get(clsName));
51 }
52
53 private static class FieldKey implements Comparable {
54 private String fieldName;
55 private Class declaringClass;
56 private Integer depth;
57
58 public FieldKey(String fieldName, Class declaringClass) {
59 this.fieldName = fieldName;
60 this.declaringClass = declaringClass;
61 Class c = declaringClass;
62 int i = 0;
63 while (c.getSuperclass() != null) {
64 i++;
65 c = c.getSuperclass();
66 }
67 depth = new Integer (i);
68 }
69
70 public int compareTo(Object o) {
71 FieldKey t = (FieldKey) o;
72 int result = fieldName.compareTo(t.fieldName);
73 if (result == 0) {
74 result = 0 - depth.compareTo(t.depth);
75 }
76 if (result == 0) {
77 result = declaringClass.getName().compareTo(t.declaringClass.getName());
78 }
79 return result;
80 }
81 }
82
83 }
84 |
Popular Tags |
Java API By Example, From Geeks To Geeks.