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1
6
7 package com.memoire.vainstall;
8
9 import java.io.ByteArrayOutputStream  ;
10 import java.io.File ;
11 import java.io.FileInputStream ;
12 import java.io.IOException ;
13 import java.io.InputStream ;
14 import java.net.MalformedURLException ;
15 import java.net.URL ;
16 import java.util.Hashtable ;
17 import java.util.jar.JarInputStream ;
18 import java.util.zip.ZipEntry ;
19
20
24
25 public class VAClassLoader extends ClassLoader
26 {
27 public final static boolean DEBUG="yes".equals(System.getProperty("DEBUG"));
28
29
32 private Hashtable cache_;
33
34 private long offset_;
35 private File jarfile_;
36 private File dllFile_;
37
38
39
42 private Hashtable classes = new Hashtable ();
43
44 public VAClassLoader(File jarfile, Long offset)
45 {
46 super();
47 offset_=offset.longValue();
48 jarfile_=jarfile;
49 JarInputStream jar=null;
50 try {
51 cache_=new Hashtable ();
52 printDebug("VAClassLoader: loading classes from "+jarfile.getName()+" (offset "+offset_+")...");
53 FileInputStream stream=new FileInputStream (jarfile_);
54 stream.skip(offset_);
55 jar=new JarInputStream (stream);
56 ZipEntry entry=jar.getNextEntry();
57 byte[] data=null;
58 Class c=null;
59 while( entry!=null ) {
60 String entryName=entry.getName();
61 if( entryName.endsWith(".class") ) {
62
63 byte[] buffer = new byte[2048];
64 ByteArrayOutputStream bos = new ByteArrayOutputStream ();
65 while(true)
66 {
67 int read = jar.read(buffer);
68 if(read == -1)break;
69 bos.write(buffer, 0, read);
70 }
71 data = bos.toByteArray();
72 bos.close();
73 jar.closeEntry();
74 String className=entryName.replace('/', '.'); printDebug(" className="+className+" size="+data.length);
76
77 byte[] toCache = new byte[data.length];
78 System.arraycopy(data,0,toCache,0,data.length);
79 cache_.put(className, data);
80
81 }
82 entry=jar.getNextEntry();
83 }
84 } catch( Throwable t ) {
85 t.printStackTrace();
86 } finally {
87 printDebug(" closing jarFile.");
88 if( jar!=null ) try {jar.close();} catch( IOException e ) {System.err.println(e);}
89 }
90 }
91
92
93 public Class loadClass(String className)
94 throws ClassNotFoundException
95 {
96 return (loadClass(className, true));
97 }
98
99 public synchronized Class loadClass(String className,boolean resolveIt)
100 throws ClassNotFoundException
101 {
102
103 Class result;
104 byte[] classBytes;
105
106 result = (Class )classes.get(className);
108 if (result != null) {
109 return result;
110 }
111
112 try {
114 result = super.findSystemClass(className);
115 return result;
116 } catch (ClassNotFoundException e) {
117 }
118
119 printDebug(className);
122 classBytes = loadClassBytes(className);
123 if (classBytes == null) {
124 throw new ClassNotFoundException ();
125 }
126
127 result = defineClass(className, classBytes, 0, classBytes.length);
129 if (result == null) {
130 throw new ClassFormatError ();
131 }
132
133 if (resolveIt) resolveClass(result);
135
136 classes.put(className, result);
138 return result;
139 }
140
141
142 public synchronized InputStream getResourceAsStream(String name)
143 {
144 InputStream res=null;
145 JarInputStream jar=null;
146 try {
147 printDebug("VAClassLoader: loading resource "+name);
148 FileInputStream stream=new FileInputStream (jarfile_);
149 stream.skip(offset_);
150 jar=new JarInputStream (stream);
151 ZipEntry entry=jar.getNextEntry();
152 while( (entry!=null)&&
153 (!entry.getName().equals(name)) )
154 entry=jar.getNextEntry();
155 if( entry!=null ) {
156 res=jar;
157 }
158 } catch( IOException t ) {
159 System.err.println(t);
160 printDebug(" closing jarFile.");
161 if( jar!=null ) try {jar.close();} catch( IOException e ) {System.err.println(e);}
162 }
163 if( res==null ) printDebug(" not found");
164 else printDebug(" OK");
165 return res;
166 }
167
168 public synchronized URL getResource(String name)
169 {
170 URL res=null;
171 try {
172 printDebug("VAClassLoader: loading resource URL "+name);
173 String jarUrl=jarfile_.toURL().toString();
174 jarUrl="jar:"+jarUrl+"!"+name;
175 res=new URL (jarUrl);
176 } catch( MalformedURLException ex ) {
177 printDebug(" null URL");
178 res=null;
179 }
180 if( res==null ) printDebug(" not found");
181 else printDebug(" OK");
182 return res;
183 }
184
185 protected void finalize()
186 {
187 if( dllFile_.exists() ) dllFile_.delete();
188 }
189
190 public static void printDebug(String msg)
191 {
192 if(DEBUG) System.err.println(msg);
193 }
194
195 protected byte[] loadClassBytes (String className)
196 {
197 className = formatClassName(className);
199 printDebug("Trying to fetch="+className);
200 return (byte[])cache_.get(className);
202 }
203
204 protected String formatClassName(String className)
205 {
206 return className + ".class";
207 }
208
209 }
210
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