moved the code to locate the source jar file.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@2291 71c3de6d-444a-0410-be80-ed276b4c234a

remoting/src/main/java/hudson/remoting/Which.java

+package hudson.remoting;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.URL;
+
+/**
+ * Locates where a given class is loaded from.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public class Which {
+    public static File jarFile(Class clazz) throws IOException {
+        String res = clazz.getClassLoader().getResource(clazz.getName().replace('.', '/') + ".class").toExternalForm();
+        if(res.startsWith("jar:")) {
+            res = res.substring(4,res.lastIndexOf('!')); // cut off jar: and the file name portion
+            return new File(decode(new URL(res).getPath()));
+        }
+
+        if(res.startsWith("file:")) {
+            // unpackaged classes
+            int n = clazz.getName().split("\\.").length; // how many slashes do wo need to cut?
+            for( ; n>0; n-- ) {
+                int idx = Math.max(res.lastIndexOf('/'), res.lastIndexOf('\\'));
+                res = res.substring(0,idx);
+            }
+
+            // won't work if res URL contains ' '
+            // return new File(new URI(null,new URL(res).toExternalForm(),null));
+            // won't work if res URL contains '%20'
+            // return new File(new URL(res).toURI());
+
+            return new File(decode(new URL(res).getPath()));
+        }
+
+        throw new IllegalArgumentException(res);
+    }
+
+    /**
+     * Decode '%HH'.
+     */
+    private static String decode(String s) {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        for( int i=0; i<s.length();i++ ) {
+            char ch = s.charAt(i);
+            if(ch=='%') {
+                baos.write(hexToInt(s.charAt(i+1))*16 + hexToInt(s.charAt(i+2)));
+                i+=2;
+                continue;
+            }
+            baos.write(ch);
+        }
+        try {
+            return new String(baos.toByteArray(),"UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new Error(e); // impossible
+        }
+    }
+
+    private static int hexToInt(int ch) {
+        return Character.getNumericValue(ch);
+    }
+}