Merge pull request #59 from utPLSQL/bugfix/nls_from_environment

Added locale initialization from environment variables NLS_LANG, LC_ALL or LANG

Fixes #56

Author: pesse

README.md

@@ -27,6 +27,17 @@ You can also download all development versions from [Bintray](https://bintray.co
 The latest CLI is always compatible with all database frameworks of the same minor version.
 For example CLI-3.0.4 is compatible with database framework 3.0.0-3.0.4 but not with database framework 2.x and 3.1.x.
 
+## Localization and NLS settings
+utPLSQL-cli will use the environment variables (in that order) "NLS_LANG", "LC_ALL" or "LANG" to change the locale and therefore the NLS settings.
+If neither environment variable is available, it will use the JVM default locale.
+
+Example: to change the NLS-settings to English American, you can do the following:
+```
+export LC_ALL=en_US.utf-8
+```
+
+The charset-part of LC_ALL is ignored.
+
 ## Usage
 
 `utplsql run <ConnectionURL> [-p=(ut_path|ut_paths)] [-f=format [-o=output_file] [-s] ...]`

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 +1,64 @@
+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 NLS_LANG is set, we try to parse its content and set locale according to its value if valid
+ *   2. If environment variable LC_ALL is set, we try to parse its content and set locale according to its value if valid
+ *   3. If environment variable LANG is set, we try to parse its content and set locale according to its value if valid
+ *   4. 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() {
+
+        boolean localeChanged = setDefaultLocale(System.getenv("NLS_LANG"));
+
+        if ( !localeChanged )
+            localeChanged = setDefaultLocale(System.getenv("LC_ALL"));
+        if ( !localeChanged )
+            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;
+    }
+}