Unify java path search

JavaConfig.java

@@ -0,0 +1,107 @@
+/* JavaConfig - tool for getting paths for current java environment.
+ * © 2011  Petr Písař <ppisar@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+class JavaConfig {
+  private static String output = "";
+
+
+  /*
+   * Append text to output with proper padding or terminates if text is null.
+   * @param text String to append.
+   */
+  private static void concatenate(String text) {
+    if (text == null) {
+      System.exit(2);
+    }
+    output = (output.equals("") ? ""  : output + " " ) + text;
+  }
+
+
+  /*
+   * Show usage message and terminates program with given @exit_code.
+   * @param exit_code code to return
+   * */
+  private static void usage(int exitCode) {
+    System.out.print(
+        "JavaConfig [OPTIONS]\n" +
+        "  --home         Output path to Java home\n" +
+        "  --libs-only-L  Output -L linker flags\n"
+    );
+    System.exit(exitCode);
+  }
+
+
+  /*
+   * @Return path to Java home or null in case of error.
+   */
+  public static String home() {
+    return System.getProperty("java.home");
+  }
+
+
+  /*
+   * @Return formated libary search path as -L compiler flag,
+   * null if error occured.
+   * */
+  public static String libsOnlyL() {
+    String value;
+    String paths[];
+   
+    if (null == (value = System.getProperty("java.library.path"))) {
+      return null;
+    }
+
+    paths = value.split(":");
+
+    for (int i = 0; i < paths.length; i++) {
+      if (paths[i].equals("")) {
+        continue;
+      }
+      
+      if (i == 0) {
+        value = "-L" + paths[i];
+      } else {
+        value = value + " -L" + paths[i];
+      }
+    }
+
+    return value;
+  }
+
+
+  /*
+   * Entry point to this class.
+   */
+  public static void main(String argv[]) {
+    if (argv.length < 1) {
+      usage(1);
+    }
+
+    for (int i = 0; i < argv.length; i++) {
+      if (argv[i].equals("--home")) {
+          concatenate(home());
+      } else if (argv[i].equals("--libs-only-L")) {
+          concatenate(libsOnlyL());
+      } else {
+          usage(1);
+      }
+    }
+
+    System.out.println(output);
+    System.exit(0);
+  }
+}