Corrected exceptions and added alphabet methods

Author: rijnb

src/main/java/com/mapcode/Alphabet.java

@@ -17,6 +17,10 @@
 package com.mapcode;
 
 import javax.annotation.Nonnull;
+import java.util.HashSet;
+import java.util.Set;
+
+import static com.mapcode.CheckArgs.checkNonnull;
 
 /**
  * This enum defines all alphabets supported for mapcodes. Mapcodes can be safely converted between
@@ -38,12 +42,16 @@ public enum Alphabet {
     GURMUKHI(12),
     TIBETAN(13);
 
-    public final int code;
+    private final int code;
 
     private Alphabet(final int code) {
         this.code = code;
     }
 
+    public int getCode() {
+        return code;
+    }
+
     @Nonnull
     public static Alphabet fromCode(final int code) throws UnknownAlphabetException {
         for (final Alphabet alphabet : values()) {
@@ -54,12 +62,47 @@ public static Alphabet fromCode(final int code) throws UnknownAlphabetException
         throw new UnknownAlphabetException(code);
     }
 
-    public static class UnknownAlphabetException extends RuntimeException {
-        final int code;
+    /**
+     * Return alphabet from a string, which can be a numeric or alpha code.
+     *
+     * @param numericOrAlpha Alphabet. May be a numeric or alphanumeric code.
+     * @return Alphabet.
+     * @throws UnknownAlphabetException Thrown if incorrect numeric or alphanumeric code.
+     */
+    @Nonnull
+    public static Alphabet fromString(@Nonnull final String numericOrAlpha) throws UnknownAlphabetException {
+        checkNonnull("name", numericOrAlpha);
+        final String trimmed = numericOrAlpha.trim().toUpperCase();
+        try {
+            return fromCode(Integer.valueOf(numericOrAlpha));
+        } catch (final IllegalArgumentException ignored) {
+            // Ignore. Re-try as alpha code.
+        }
+        try {
+            return valueOf(trimmed);
+        } catch (final IllegalArgumentException ignored) {
+            throw new UnknownAlphabetException(trimmed);
+        }
+    }
+
+    /**
+     * Static checking of the static data structures.
+     */
+    static {
+        final String errorPrefix = "Initializing error: ";
+        final Set<Integer> alphabetCodeList = new HashSet<>();
+
+        for (final Alphabet alphabet : Alphabet.values()) {
+            final int alphabetCode = alphabet.getCode();
+            if ((alphabetCode < 0) || (alphabetCode >= Alphabet.values().length)) {
+                throw new ExceptionInInitializerError(errorPrefix + "alphabet code out of range: " + alphabetCode);
 
-        public UnknownAlphabetException(final int code) {
-            super();
-            this.code = code;
+            }
+            if (alphabetCodeList.contains(alphabetCode)) {
+                throw new ExceptionInInitializerError(errorPrefix + "non-unique alphabet code: " + alphabetCode);
+            }
+            alphabetCodeList.add(alphabet.getCode());
         }
+        assert alphabetCodeList.size() == Alphabet.values().length;
     }
 }

src/main/java/com/mapcode/Decoder.java

@@ -79,7 +79,7 @@ static Point decode(@Nonnull final String argMapcode,
             }
         }
 
-        final int ccode = territory.getTerritoryCode();
+        final int ccode = territory.getCode();
 
         final int from = DataAccess.dataFirstRecord(ccode);
         if (DataAccess.dataFlags(from) == 0) {

src/main/java/com/mapcode/Encoder.java

@@ -97,12 +97,12 @@ private static List<Mapcode> encode(final double argLatDeg, final double argLonD
                 continue;
             }
 
-            final int from = DataAccess.dataFirstRecord(currentEncodeTerritory.getTerritoryCode());
+            final int from = DataAccess.dataFirstRecord(currentEncodeTerritory.getCode());
             final Data mapcoderData = new Data(from);
             if (mapcoderData.getFlags() == 0) {
                 continue;
             }
-            final int upto = DataAccess.dataLastRecord(currentEncodeTerritory.getTerritoryCode());
+            final int upto = DataAccess.dataLastRecord(currentEncodeTerritory.getCode());
 
 
             final int i = subArea.getSubAreaID();

src/main/java/com/mapcode/Mapcode.java

@@ -87,7 +87,7 @@ public Mapcode(
 
         checkMapcodeCode("code", code);
         if (containsTerritory(code)) {
-            throw new IllegalArgumentException("code cannot territory information: " + code);
+            throw new IllegalArgumentException("Must not contain territory: " + code);
         }
         final String codeUppercase = code.toUpperCase();
         this.codePrecision2 = codeUppercase;
@@ -140,6 +140,7 @@ public String getCode() {
      * @param precision Precision. Range: 0..2.
      * @param alphabet  Alphabet.
      * @return Mapcode code.
+     * @throws IllegalArgumentException Thrown if precision is out of range (must be in [0, 2]).
      */
     @Nonnull
     public String getCode(final int precision, @Nullable final Alphabet alphabet) {
@@ -156,7 +157,7 @@ public String getCode(final int precision, @Nullable final Alphabet alphabet) {
     }
 
     @Nonnull
-    public String getCode(final int precision) {
+    public String getCode(final int precision) throws IllegalArgumentException {
         return getCode(precision, null);
     }
 
@@ -172,14 +173,15 @@ public String getCode(final int precision) {
      * @param precision Precision specifier. Range: [0, 2].
      * @param alphabet  Alphabet.
      * @return Full international mapcode.
+     * @throws IllegalArgumentException Thrown if precision is out of range (must be in [0, 2]).
      */
     @Nonnull
-    public String getCodeWithTerritoryFullname(final int precision, @Nullable final Alphabet alphabet) {
+    public String getCodeWithTerritoryFullname(final int precision, @Nullable final Alphabet alphabet) throws IllegalArgumentException {
         return territory.getFullName() + ' ' + getCode(precision, alphabet);
     }
 
     @Nonnull
-    public String getCodeWithTerritoryFullname(final int precision) {
+    public String getCodeWithTerritoryFullname(final int precision) throws IllegalArgumentException {
         return getCodeWithTerritoryFullname(precision, null);
     }
 
@@ -206,14 +208,15 @@ public String getCodeWithTerritoryFullname() {
      * @param precision Precision specifier. Range: [0, 2].
      * @param alphabet  Alphabet.
      * @return Short-hand international mapcode.
+     * @throws IllegalArgumentException Thrown if precision is out of range (must be in [0, 2]).
      */
     @Nonnull
-    public String getCodeWithTerritory(final int precision, @Nullable final Alphabet alphabet) {
+    public String getCodeWithTerritory(final int precision, @Nullable final Alphabet alphabet) throws IllegalArgumentException {
         return territory.toString() + ' ' + getCode(precision, alphabet);
     }
 
     @Nonnull
-    public String getCodeWithTerritory(final int precision) {
+    public String getCodeWithTerritory(final int precision) throws IllegalArgumentException {
         return getCodeWithTerritory(precision, null);
     }
 
@@ -389,12 +392,12 @@ static String convertMapcodeToPlainAscii(@Nonnull final String mapcode) {
      * @param mapcode  Mapcode (optionally with a territory) to be converted.
      * @param alphabet Alphabet to convert to, may contain Unicode characters.
      * @return Converted mapcode.
-     * @throws IllegalArgumentException If mapcode has incorrect syntax.
+     * @throws IllegalArgumentException Thrown if mapcode has incorrect syntax.
      */
     @Nonnull
     static String convertMapcodeToAlphabet(@Nonnull final String mapcode, @Nullable final Alphabet alphabet) throws IllegalArgumentException {
         checkMapcodeCode("mapcode", mapcode);
-        return (alphabet != null) ? Decoder.encodeUTF16(mapcode.toUpperCase(), alphabet.code) : mapcode.toUpperCase();
+        return (alphabet != null) ? Decoder.encodeUTF16(mapcode.toUpperCase(), alphabet.getCode()) : mapcode.toUpperCase();
     }
 
     /**

src/main/java/com/mapcode/SubArea.java

@@ -45,7 +45,7 @@ class SubArea {
 
     static {
         for (final Territory territory : Territory.values()) {
-            final int territoryCode = territory.getTerritoryCode();
+            final int territoryCode = territory.getCode();
             final int first = DataAccess.dataFirstRecord(territoryCode);
             final int last = DataAccess.dataLastRecord(territoryCode);