Add config and formatter data set to concurrent map

src/main/kotlin/com/cubetiqs/money/MoneyConfig.kt

@@ -1,5 +1,8 @@
 package com.cubetiqs.money
 
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ConcurrentMap
+
 /**
  * Default money config in static object.
  * Sample parse format: USD=1,KHR=4000,EUR=0.99
@@ -14,10 +17,10 @@ object MoneyConfig {
      * Key is the currency
      * Value is the rate
      */
-    private val config: MutableMap<String, Double> = mutableMapOf()
+    private val config: ConcurrentMap<String, Double> = ConcurrentHashMap()
 
     // use to format the money for each value, if have
-    private val configFormatter: MutableMap<String, MoneyFormatProvider> = mutableMapOf()
+    private val configFormatter: ConcurrentMap<String, MoneyFormatProvider> = ConcurrentHashMap()
 
     // use to identified for config dataset with prefix mode
     private var configPrefix: String = ""

src/main/kotlin/com/cubetiqs/money/MoneyExtension.kt

@@ -1,5 +1,7 @@
 package com.cubetiqs.money
 
+import java.util.*
+
 infix fun StdMoney.exchangeTo(currency: StdMoney.Currency): StdMoney {
     return MoneyExchangeUtils.exchange(this, currency)
 }
@@ -127,3 +129,8 @@ fun MoneyView.asStdMoney(): StdMoney {
         }
     }
 }
+
+// detect currency symbol, if needed
+fun StdMoney.Currency.findCurrency(): Currency? {
+    return Currency.getInstance(this.getCurrency())
+}

src/main/kotlin/com/cubetiqs/money/MoneyView.kt

@@ -4,9 +4,12 @@ open class MoneyView(
     private var value: Number? = null,
     private var currency: String? = null,
 ) : MoneyMixin {
+    private var _currency: StdMoney.Currency? = null
+
     constructor(money: StdMoney) : this() {
+        this._currency = money.getCurrency()
         this.value = money.getValue()
-        this.currency = money.getCurrency().getCurrency()
+        this.currency = this._currency?.getCurrency()
     }
 
     fun getValue(): Double {
@@ -17,6 +20,10 @@ open class MoneyView(
         return currency
     }
 
+    fun getSymbol(): String? {
+        return this._currency?.findCurrency()?.symbol
+    }
+
     fun getFormat(): String {
         return MoneyConfig
             .getFormatter(getCurrency())