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1
17 package com.sun.syndication.io.impl;
18
19 import java.util.*;
20 import java.io.IOException  ;
21 import java.io.InputStream ;
22 import java.net.URL ;
23
24
29 public abstract class PluginManager {
30 private Map _pluginsMap;
31 private List _pluginsList;
32 private List _keys;
33
34
40 protected PluginManager(String propertyKey) {
41 loadPlugins(propertyKey);
42 _pluginsMap = Collections.unmodifiableMap(_pluginsMap);
43 _pluginsList = Collections.unmodifiableList(_pluginsList);
44 _keys = Collections.unmodifiableList(new ArrayList(_pluginsMap.keySet()));
45 }
46
47 protected abstract String getKey(Object obj);
48
49
50 protected List getKeys() {
51 return _keys;
52 }
53
54 protected List getPlugins() {
55 return _pluginsList;
56 }
57
58 protected Map getPluginMap() {
59 return _pluginsMap;
60 }
61
62 protected Object getPlugin(String key) {
63 return _pluginsMap.get(key);
64 }
65
66
68 private void loadPlugins(String key) {
69 List finalPluginsList = new ArrayList();
70 _pluginsList = new ArrayList();
71 _pluginsMap = new HashMap();
72 try {
73 Class [] classes = getClasses(key);
74 for (int i=0;i<classes.length;i++) {
75 Object obj = classes[i].newInstance();
76 _pluginsMap.put(getKey(obj),obj);
77 _pluginsList.add(obj); }
79 Iterator i = _pluginsMap.values().iterator();
80 while (i.hasNext()) {
81 finalPluginsList.add(i.next()); }
83
84 i = _pluginsList.iterator();
85 while (i.hasNext()) {
86 Object plugin = i.next();
87 if (!finalPluginsList.contains(plugin)) {
88 i.remove();
89 }
90 }
91 }
92 catch (Exception ex) {
93 throw new RuntimeException ("could not instanciate plugin ",ex);
94 }
95 }
96
97 private static final String MASTER_PLUGIN_FILE = "com/sun/syndication/rome.properties";
98 private static final String EXTRA_PLUGIN_FILE = "rome.properties";
99 private static final Properties[] PLUGINS_DEFS;
100
101 static {
102 PLUGINS_DEFS = loadAllProperties();
103 }
104
105 private static Properties[] loadAllProperties() {
106 ClassLoader classLoader = PluginManager.class.getClassLoader();
107 List allProps = new ArrayList();
108
109 try {
110 InputStream is = classLoader.getResourceAsStream(MASTER_PLUGIN_FILE);
112 allProps.add(loadProperties(is));
113 }
114 catch (IOException ex) {
115 throw new RuntimeException ("could not load Rome plugins file",ex);
116 }
117
118 try {
120 Enumeration urls = classLoader.getResources(EXTRA_PLUGIN_FILE);
121 while (urls.hasMoreElements()) {
122 URL url = (URL ) urls.nextElement();
123 try {
124 InputStream is = url.openStream();
125 allProps.add(loadProperties(is));
126 }
127 catch (IOException ex) {
128 throw new RuntimeException ("could not load Rome extensions plugins file ["+url.toString()+"] ",ex);
129 }
130 }
131 }
132 catch (IOException ex) {
133 throw new RuntimeException ("could not load fetch resources for Rome extensions plugins");
134 }
135
136 Properties[] array = new Properties[allProps.size()];
137 allProps.toArray(array);
138 return array;
139 }
140
141 private static Properties loadProperties(InputStream is) throws IOException {
142 Properties props = new Properties();
143 props.load(is);
144 return props;
145 }
146
147 private static List parseAndLoadClasses(String classNames) throws ClassNotFoundException {
148 ClassLoader classLoader = PluginManager.class.getClassLoader();
149 List classes = new ArrayList();
150 StringTokenizer st = new StringTokenizer(classNames,", ");
151 while (st.hasMoreTokens()) {
152 String className = st.nextToken();
153 Class mClass = classLoader.loadClass(className);
154 classes.add(mClass);
155 }
156 return classes;
157 }
158
159
168 private static Class [] getClasses(String pluginKey) throws ClassNotFoundException {
169 List classes = new ArrayList();
170 for (int i=0;i<PLUGINS_DEFS.length;i++) {
171 String classNames = PLUGINS_DEFS[i].getProperty(pluginKey);
172 if (classNames!=null) {
173 classes.addAll(parseAndLoadClasses(classNames));
174 }
175 }
176 Class [] array = new Class [classes.size()];
177 classes.toArray(array);
178 return array;
179 }
180
181
182
183 }
184 |
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