Implement configurable currency formatting.

This commit enables users of different countries around the world to configure currency formatting displayed to users in a familiar manner.

Prior to this commit US formatting (symbols) was forced upon users. This is now configurable via locale values e.g. en-US, de, fr-ch.

This commit adds two new configurations:
- currency-format
- currency-symbol-format-locale

One method ISettings#getCurrencyFormat()

Essentials/src/com/earth2me/essentials/ISettings.java

@@ -8,6 +8,7 @@ import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.event.EventPriority;
 
 import java.math.BigDecimal;
+import java.text.NumberFormat;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -243,4 +244,6 @@ public interface ISettings extends IConf {
     boolean isSendFlyEnableOnJoin();
     
     boolean isWorldTimePermissions();
+    
+    NumberFormat getCurrencyFormat();
 }

Essentials/src/com/earth2me/essentials/Settings.java

@@ -6,6 +6,8 @@ import com.earth2me.essentials.signs.Signs;
 import com.earth2me.essentials.textreader.IText;
 import com.earth2me.essentials.textreader.SimpleTextInput;
 import com.earth2me.essentials.utils.FormatUtil;
+import com.earth2me.essentials.utils.NumberUtil;
+
 import net.ess3.api.IEssentials;
 import org.bukkit.ChatColor;
 import org.bukkit.configuration.ConfigurationSection;
@@ -14,13 +16,22 @@ import org.bukkit.event.EventPriority;
 import org.bukkit.inventory.ItemStack;
 
 import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.text.NumberFormat;
 import java.util.*;
+import java.util.Locale.Category;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import static com.earth2me.essentials.I18n.tl;
 
+import com.google.common.base.Preconditions;
+
 
 public class Settings implements net.ess3.api.ISettings {
     private final transient EssentialsConf config;
@@ -532,6 +543,8 @@ public class Settings implements net.ess3.api.ISettings {
         customQuitMessage = _getCustomQuitMessage();
         isCustomQuitMessage = !customQuitMessage.equals("none");
         muteCommands = _getMuteCommands();
+        
+        currencyFormat = _getCurrencyFormat();
     }
 
     private List<Integer> itemSpawnBl = new ArrayList<Integer>();
@@ -1163,4 +1176,47 @@ public class Settings implements net.ess3.api.ISettings {
     public boolean isWorldTimePermissions() {
         return config.getBoolean("world-time-permissions", false);
     }
+    
+    private NumberFormat currencyFormat;
+
+    private NumberFormat _getCurrencyFormat() {
+        String currencyFormatString = config.getString("currency-format", "#,##0.00");
+        
+        String symbolLocaleString = config.getString("currency-symbol-format-locale");
+        DecimalFormatSymbols decimalFormatSymbols;
+        if (symbolLocaleString != null) {
+            decimalFormatSymbols = DecimalFormatSymbols.getInstance(Locale.forLanguageTag(symbolLocaleString));
+        } else {
+            // Fallback to the JVM's default locale
+            decimalFormatSymbols = DecimalFormatSymbols.getInstance();
+        }
+
+        DecimalFormat currencyFormat = new DecimalFormat(currencyFormatString, decimalFormatSymbols);
+        currencyFormat.setRoundingMode(RoundingMode.FLOOR);
+        
+        // Updates NumberUtil#PRETTY_FORMAT field so that all of Essentials
+        // can follow a single format.
+        try {
+            Field field = NumberUtil.class.getDeclaredField("PRETTY_FORMAT");
+            field.setAccessible(true);
+            Field modifiersField = Field.class.getDeclaredField("modifiers");
+            modifiersField.setAccessible(true);
+            modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
+            field.set(null, currencyFormat);
+            modifiersField.setAccessible(false);
+            field.setAccessible(false);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            ess.getLogger().severe("Failed to apply custom currency format: " + e.getMessage());
+            if (isDebug()) {
+                e.printStackTrace();
+            }
+        }
+
+        return currencyFormat;
+    }
+
+    @Override
+    public NumberFormat getCurrencyFormat() {
+        return this.currencyFormat;
+    }
 }

Essentials/src/com/earth2me/essentials/utils/NumberUtil.java

@@ -15,6 +15,9 @@ import static com.earth2me.essentials.I18n.tl;
 public class NumberUtil {
     static DecimalFormat twoDPlaces = new DecimalFormat("#,###.##");
     static DecimalFormat currencyFormat = new DecimalFormat("#0.00", DecimalFormatSymbols.getInstance(Locale.US));
+    
+    // This field is likely to be modified in com.earth2me.essentials.Settings when loading currency format.
+    // This ensures that we can supply a constant formatting.
     static final NumberFormat PRETTY_FORMAT = NumberFormat.getInstance(Locale.US);
 
     static {

Essentials/src/config.yml

@@ -560,6 +560,19 @@ use-bukkit-permissions: false
 # Minimum acceptable amount to be used in /pay.
 minimum-pay-amount: 0.001
 
+# The format of currency, excluding symbols. See currency-sumbol-format-locale for symbol configuration.
+#
+# "#,##0.00" is how the majority of countries display currency.
+#currency-format: "#,##0.00"
+
+# Format currency symbols. Some locales use , and . interchangeably.
+# Some formats do not display properly in-game due to faulty Minecraft font rendering.
+#
+# For 1.234,50 use de-DE
+# For 1,234.50 use en-US
+# For 1'234,50 use fr-ch
+#currency-symbol-format-locale: en-US
+
 ############################################################
 # +------------------------------------------------------+ #
 # |                   EssentialsHelp                     | #