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1
4 package com.tc.util.factory;
5
6 import java.io.BufferedReader  ;
7 import java.io.IOException ;
8 import java.io.InputStream ;
9 import java.io.InputStreamReader ;
10
11 public abstract class AbstractFactory {
12 public static AbstractFactory getFactory(String id, Class defaultImpl) {
13 String factoryClassName = findFactoryClassName(id);
14 AbstractFactory factory = null;
15
16 if(factoryClassName != null) {
17 try {
18 factory = (AbstractFactory)Class.forName(factoryClassName).newInstance();
19 } catch(Exception e) {
20 throw new RuntimeException ("Could not instantiate '"+factoryClassName+"'", e);
21 }
22 }
23
24 if(factory == null) {
25 try {
26 factory = (AbstractFactory)defaultImpl.newInstance();
27 } catch(Exception e) {
28 throw new RuntimeException (e);
29 }
30 }
31
32 return factory;
33 }
34
35 private static String findFactoryClassName(String id) {
36 String serviceId = "META-INF/services/"+id;
37 InputStream is = null;
38
39 ClassLoader cl = AbstractFactory.class.getClassLoader();
40 if (cl != null) {
41 is = cl.getResourceAsStream(serviceId);
42 }
43
44 if (is == null) {
45 return System.getProperty(id);
46 }
47
48 BufferedReader rd;
49 try {
50 rd = new BufferedReader (new InputStreamReader (is, "UTF-8"));
51 } catch (java.io.UnsupportedEncodingException e) {
52 rd = new BufferedReader (new InputStreamReader (is));
53 }
54
55 String factoryClassName = null;
56 try {
57 factoryClassName = rd.readLine();
58 rd.close();
59 } catch(IOException x) {
60 return System.getProperty(id);
61 }
62
63 if (factoryClassName != null && !"".equals(factoryClassName)) {
64 return factoryClassName;
65 }
66
67 return System.getProperty(id);
68 }
69 }
70 |
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