Added locale initialization from environment variables LC_ALL or LANG

Fixes #56

Author: pesse

src/main/java/org/utplsql/cli/Cli.java

@@ -9,12 +9,15 @@
 
 public class Cli {
 
-    public static final int DEFAULT_ERROR_CODE = 1;
+    static final int DEFAULT_ERROR_CODE = 1;
 
-    public static final String HELP_CMD = "-h";
-    public static final String RUN_CMD = "run";
+    static final String HELP_CMD = "-h";
+    private static final String RUN_CMD = "run";
 
     public static void main(String[] args) {
+
+        LocaleInitializer.initLocale();
+
         JCommander jc = new JCommander();
         // jc.addCommand(HELP_CMD, new HelpCommand());
         RunCommand runCmd = new RunCommand();

src/main/java/org/utplsql/cli/LocaleInitializer.java

@@ -0,0 +1,58 @@
+package org.utplsql.cli;
+
+import java.util.Locale;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/** This class makes sure the java locale is set according to the environment variables LC_ALL and LANG
+ * We experienced that, in some cases, the locale was not set as expected, therefore this class implements some clear
+ * rules:
+ *   1. If environment variable LC_ALL is set, we try to parse its content and set locale according to its value if valid
+ *   2. If environment variable LANG is set, we try to parse its content and set locale according to its value if valid
+ *   3. Otherwise we use default locale
+ *
+ *   @author pesse
+ */
+class LocaleInitializer {
+
+    private static final Pattern REGEX_LOCALE = Pattern.compile("^([a-zA-Z]+)[_-]([a-zA-Z]+)"); // We only need the very first part and are pretty forgiving in parsing
+
+    /** Sets the default locale according to the rules described above
+     *
+     */
+    static void initLocale() {
+        if ( !setDefaultLocale(System.getenv("LC_ALL")))
+            setDefaultLocale(System.getenv("LANG"));
+    }
+
+    /** Set the default locale from a given string like LC_ALL or LANG environment variable
+     *
+     * @param localeString Locale-string from LC_ALL or LANG, e.g "en_US.utf-8"
+     * @return true if successful, false if not
+     */
+    private static boolean setDefaultLocale( String localeString ) {
+        if ( localeString == null || localeString.isEmpty() )
+            return false;
+
+        try {
+            Matcher m = REGEX_LOCALE.matcher(localeString);
+            if (m.find()) {
+                StringBuilder sb = new StringBuilder();
+                sb.append(m.group(1));
+                if (m.group(2) != null)
+                    sb.append("-").append(m.group(2));
+
+                Locale l = new Locale.Builder().setLanguageTag(sb.toString()).build();
+                if ( l != null ) {
+                    Locale.setDefault(l);
+                    return true;
+                }
+            }
+        }
+        catch ( Exception e ) {
+            System.out.println("Could not get locale from " + localeString);
+        }
+
+        return false;
+    }
+}