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|
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public class Util |
public class Util |
33 |
{ |
{ |
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public static InputStream getInputStream(String filename, String classpath) |
private String bootclasspath; |
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private String classpath; |
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private String userclasspath; |
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|
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public Util() |
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{ |
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classpath = System.getProperty("java.class.path"); |
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bootclasspath = System.getProperty("sun.boot.class.path"); |
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} |
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|
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/** |
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* Searches from the current working directory for a file |
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* package/classname.class unless the user supplied a classpath. If so then |
47 |
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* searches through the user supplied classpath. Finally searches the system |
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* classpath and bootclasspath. |
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* |
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* @param className the class to find |
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* @return a valid InputStream for reading the given class's class file |
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* @throws ClassNotFoundException if the class cannot be found |
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*/ |
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public InputStream findClass(String className) throws ClassNotFoundException |
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{ |
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InputStream is = null; |
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String filename = getFileNameFromClassName(className); |
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if (userclasspath != null) |
59 |
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{ |
60 |
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String path = getSearchPath(); |
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is = findClass(filename, path); |
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} |
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else |
64 |
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{ |
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is = findFile(filename); |
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} |
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if (is != null) |
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return is; |
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throw new ClassNotFoundException(className + " not found"); |
70 |
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} |
71 |
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|
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/** |
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* Attempt to get an InputStream for the specified filename. |
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* |
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* @param filename the filename to find in the specified path |
76 |
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* @param classpath the path or paths to search for the specified file |
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* @return <code>null</code> if the file cannot be found |
78 |
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*/ |
79 |
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private InputStream findClass(String filename, String classpath) |
80 |
{ |
{ |
81 |
StringTokenizer st = new StringTokenizer(classpath, File.pathSeparator); |
StringTokenizer st = new StringTokenizer(classpath, File.pathSeparator); |
82 |
while (st.hasMoreTokens()) |
while (st.hasMoreTokens()) |
123 |
} |
} |
124 |
return null; |
return null; |
125 |
} |
} |
|
} |
|
126 |
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|
127 |
|
/** |
128 |
|
* Attempt to get an InputStream for the specified filename. |
129 |
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* |
130 |
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* @param filename the filename to get an InputStream for |
131 |
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* @return <code>null</code> if the file cannot be found |
132 |
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*/ |
133 |
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private InputStream findFile(String filename) |
134 |
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{ |
135 |
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File f = new File(filename); |
136 |
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if (f.exists()) |
137 |
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{ |
138 |
|
try |
139 |
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{ |
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FileInputStream fis = new FileInputStream(f); |
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return new BufferedInputStream(fis); |
142 |
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} |
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catch (FileNotFoundException fe) |
144 |
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{ |
145 |
|
} |
146 |
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} |
147 |
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return null; |
148 |
|
} |
149 |
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|
150 |
|
/** |
151 |
|
* Class names of the form a.b.c, or simply c if the class has no package are |
152 |
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* the most common. Also support the use of filenames here, if the file exists |
153 |
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* relative to the current working directory or is absolute. |
154 |
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* |
155 |
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* @param className |
156 |
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* @return |
157 |
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*/ |
158 |
|
private String getFileNameFromClassName(String className) |
159 |
|
{ |
160 |
|
File f = new File(className); |
161 |
|
if (f.exists()) |
162 |
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return className; |
163 |
|
String filename = className.replace('.', '/'); |
164 |
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filename = filename + ".class"; |
165 |
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return filename; |
166 |
|
} |
167 |
|
|
168 |
|
/** |
169 |
|
* Used to set the user provided classpath. |
170 |
|
* |
171 |
|
* @param path the user classpath |
172 |
|
*/ |
173 |
|
public void setClasspath(String path) |
174 |
|
{ |
175 |
|
userclasspath = path; |
176 |
|
} |
177 |
|
|
178 |
|
/** |
179 |
|
* Returns the path used to find classes. To make it possible to |
180 |
|
* find classes from the user's provided classpath before finding |
181 |
|
* them in the system classpath the user's path will be first instead |
182 |
|
* of last as in Sun's implementation. |
183 |
|
* |
184 |
|
* @return the entire classpath |
185 |
|
*/ |
186 |
|
public String getSearchPath() |
187 |
|
{ |
188 |
|
StringBuffer buf = new StringBuffer(); |
189 |
|
if (userclasspath != null) |
190 |
|
buf.append(userclasspath); |
191 |
|
else |
192 |
|
{ |
193 |
|
if (bootclasspath != null) |
194 |
|
{ |
195 |
|
buf.append(bootclasspath); |
196 |
|
buf.append(File.pathSeparator); |
197 |
|
} |
198 |
|
buf.append(classpath); |
199 |
|
} |
200 |
|
return buf.toString(); |
201 |
|
} |
202 |
|
} |