Remove unnecessary lazy initialization, create more singletons

Lazy initialization only makes sense for large objects or objects whose
creation is expensive, however this is not the case here.

Also removes redundant `{@inheritdoc}` javadoc comments because documentation
is inherited by default if no javadoc comment exists.

Author: Marcono1234

src/main/java/ca/weblite/objc/Client.java

@@ -13,15 +13,14 @@
  * outputs from messages.  There are two global instances of this class
  * that are used most often:</p>
  * <ol>
- *  <li><strong><code>Client.getInstance()</code></strong> : The default
- *      client with settings to coerce both inputs and outputs.  If you
- *      need to make a direct call to the Objective-C runtime, this
- *      is usually the client that you would use.
+ *  <li>{@link #getInstance()}: The default client with settings to coerce
+ *      both inputs and outputs.  If you need to make a direct call to the
+ *      Objective-C runtime, this is usually the client that you would use.
  *  </li>
- *  <li><strong><code>Client.getRawClient()</code></strong> : Reference
- *      to a simple client that is set to <em>not</em> coerce input and
- *      output. This is handy if you want to pass in the raw Pointers
- *      as parameters, and receive raw pointers as output.
+ *  <li>{@link #getRawClient()}: Reference to a simple client that is set to
+ *      <em>not</em> coerce input and output. This is handy if you want to
+ *      pass in the raw Pointers as parameters, and receive raw pointers as
+ *      output.
  *  </li>
  * </ol>
  *
@@ -35,42 +34,28 @@ public class Client {
      * Reference to the default client instance with type coercion enabled
      * for both inputs and outputs.
      */
-    private static volatile Client instance;
+    private static final Client instance = new Client(true, true);
 
     private Client(boolean coerceInputs, boolean coerceOutputs) {
         this.coerceInputs = coerceInputs;
         this.coerceOutputs = coerceOutputs;
     }
 
-    private Client() {
-        this(true, true);
-    }
-    
     /**
      * Retrieves the global reference to a client that has both input coercion
      * and output coercion enabled.
      *
      * @return Singleton instance.
      */
     public static Client getInstance() {
-        Client localInstance = instance;
-        if (localInstance == null) {
-            // Could also use dedicated lock for `instance` and `rawClient`, but likely not worth it
-            synchronized (Client.class) {
-                localInstance = instance;
-                if (localInstance == null) {
-                    instance = localInstance = new Client();
-                }
-            }
-        }
-        return localInstance;
+        return instance;
     }
 
     /**
      * Reference to a simple client that has type coercion disabled for both
      * inputs and outputs.
      */
-    private static volatile Client rawClient;
+    private static final Client rawClient = new Client(false, false);
 
     /**
      * Retrieves singleton instance to a simple client that has type coercion
@@ -79,19 +64,7 @@ public static Client getInstance() {
      * @return a {@link ca.weblite.objc.Client} object.
      */
     public static Client getRawClient(){
-        Client localInstance = rawClient;
-        
-        if (localInstance == null ){
-            synchronized(Client.class) {
-                localInstance = rawClient;
-                if (localInstance == null) {
-                    localInstance = new Client(false, false);
-                    rawClient = localInstance;
-                }
-            }
-            
-        }
-        return localInstance;
+        return rawClient;
     }
 
     /**

src/main/java/ca/weblite/objc/TypeMapper.java

@@ -5,8 +5,6 @@
 import ca.weblite.objc.mappers.ScalarMapping;
 import ca.weblite.objc.mappers.StringMapping;
 import ca.weblite.objc.mappers.StructureMapping;
-import java.util.HashMap;
-import java.util.Map;
 
 /**
  *
@@ -22,61 +20,48 @@
  * @since 1.1
  */
 public class TypeMapper implements TypeMapping {
-    
     /**
-     * Singleton instance to the TypeMapper
+     * Singleton instance of the TypeMapper
      */
-    private static TypeMapper instance;
+    public static final TypeMapper INSTANCE = new TypeMapper();
 
     /**
-     * Obtains the singleton instance of the TypeMapper
+     * Obtains the singleton instance of the TypeMapper, i.e. {@link #INSTANCE}.
      *
-     * @return a {@link ca.weblite.objc.TypeMapper} object.
+     * @return singleton {@code TypeMapper} object.
      */
     public static TypeMapper getInstance(){
-        if ( instance == null ){
-            instance = new TypeMapper();
-        }
-        return instance;
+        return INSTANCE;
     }
 
+    private TypeMapper() { }
 
     /**
      * Maps signatures to the corresponding TypeMapping object.  Signatures
      * are <a href="https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html">Objective-C type encodings</a>.
      */
-    Map<String, TypeMapping> mappers = new HashMap<String,TypeMapping>();
-    
-    /**
-     * <p>Constructor for TypeMapper.</p>
-     */
-    public TypeMapper(){
-        init();
-    }
-    
-    
-    private void init(){
-        addMapping(new ScalarMapping(), "cCiIsSfdlLqQB[:b?#v".split(""));
-        addMapping(new StringMapping(), "*".split(""));
-        addMapping(new PointerMapping(), "^");
-        addMapping(new NSObjectMapping(), "@");
-        addMapping(new StructureMapping(), "{");
-    }
-    
-    /**
-     * Adds a TypeMapping that is meant to handle one or more signatures.
-     *
-     * @param mapping The TypeMapping object meant to handle conversions for
-     * the given signatures.
-     * @param signatures One or more signatures following <a href="https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html">Objective-C type encodings</a>.
-     * @return Self for chaining.
-     */
-    public TypeMapper addMapping(TypeMapping mapping, String... signatures){
-        
-        for ( int i=0; i<signatures.length; i++){
-            mappers.put(signatures[i], mapping);
+    private static TypeMapping getMapping(char typeChar) {
+        switch (typeChar) {
+            case 'c': case 'C':
+            case 'i': case 'I':
+            case 's': case 'S':
+            case 'f': case 'd':
+            case 'l': case 'L':
+            case 'q': case 'Q':
+            case 'b': case 'B':
+            case '[': case ':': case '?': case '#': case 'v':
+                return ScalarMapping.INSTANCE;
+            case '*':
+                return StringMapping.INSTANCE;
+            case '^':
+                return PointerMapping.INSTANCE;
+            case '@':
+                return NSObjectMapping.INSTANCE;
+            case '{':
+                return StructureMapping.INSTANCE;
+            default:
+                throw new IllegalArgumentException("Unknown type: " + typeChar);
         }
-        return this;
     }
 
     /**
@@ -100,14 +85,9 @@ public Object cToJ(Object cVar, String signature, TypeMapping root) {
             signature = signature.substring(offset);
         }
 
-        String firstChar = signature.substring(0,1);
-        TypeMapping mapping = mappers.get(firstChar);
-        if ( mapping == null ){
-            // We couldn't find a mapper for this type
-            throw new RuntimeException("No mapper registered for type "+firstChar);
-        } else {
-            return mapping.cToJ(cVar, signature, root);
-        }
+        char typeChar = signature.charAt(0);
+        TypeMapping mapping = getMapping(typeChar);
+        return mapping.cToJ(cVar, signature, root);
     }
 
     /**
@@ -138,14 +118,9 @@ public Object jToC(Object jVar, String signature, TypeMapping root) {
             signature = signature.substring(offset);
         }
 
-        String firstChar = signature.substring(0,1);
-        TypeMapping mapping = mappers.get(firstChar);
-        if ( mapping == null ){
-            // We couldn't find a mapper for this type
-            throw new RuntimeException("No mapper registered for type "+firstChar);
-        } else {
-            return mapping.jToC(jVar, signature, root);
-        }
+        char typeChar = signature.charAt(0);
+        TypeMapping mapping = getMapping(typeChar);
+        return mapping.jToC(jVar, signature, root);
     }
 
 }

src/main/java/ca/weblite/objc/mappers/NSObjectMapping.java

@@ -16,17 +16,22 @@
  * @version $Id: $Id
  * @since 1.1
  */
-public class NSObjectMapping implements TypeMapping{
+public class NSObjectMapping implements TypeMapping {
+    /**
+     * Singleton instance.
+     */
+    public static final NSObjectMapping INSTANCE = new NSObjectMapping();
+    
+    private NSObjectMapping() { }
 
-    /** {@inheritDoc} */
     @Override
     public Object cToJ(Object cVar, String signature, TypeMapping root) {
         //System.out.println("Mapping NSObject to Java "+cVar+" sig: "+signature);
         Pointer cObj = Pointer.NULL;
         if ( Pointer.class.isInstance(cVar) ){
             cObj = (Pointer)cVar;
         } else if (long.class.isInstance(cVar) || Long.class.isInstance(cVar) ){
-            cObj = new Pointer((Long)cVar);
+            cObj = new Pointer((long) cVar);
         } else {
             return cVar;
         }
@@ -35,10 +40,7 @@ public Object cToJ(Object cVar, String signature, TypeMapping root) {
             return null;
         }
         String clsName = Runtime.INSTANCE.object_getClassName(cObj);
-        boolean isString = false;
-        if ( "NSString".equals(clsName) || "NSTaggedPointerString".equals(clsName) || "NSMutableString".equals(clsName) || "__NSCFString".equals(clsName)){
-            isString = true;
-        }
+        boolean isString = "NSString".equals(clsName) || "NSTaggedPointerString".equals(clsName) || "NSMutableString".equals(clsName) || "__NSCFString".equals(clsName);
 
 
         ////System.out.println("Checking if object is a string "+isString+", "+clsName);
@@ -53,7 +55,6 @@ public Object cToJ(Object cVar, String signature, TypeMapping root) {
         }
     }
 
-    /** {@inheritDoc} */
     @Override
     public Object jToC(Object jVar, String signature, TypeMapping root) {
         if ( jVar == null ){

src/main/java/ca/weblite/objc/mappers/PointerMapping.java

@@ -1,8 +1,5 @@
 package ca.weblite.objc.mappers;
 
-import java.util.HashMap;
-import java.util.Map;
-
 import com.sun.jna.Pointer;
 
 import ca.weblite.objc.TypeMapping;
@@ -15,26 +12,19 @@
  * @since 1.1
  */
 public class PointerMapping implements TypeMapping {
-    
-    Map<String,TypeMapping> mappers = new HashMap<String, TypeMapping>();
-    
     /**
-     * <p>Constructor for PointerMapping.</p>
+     * Singleton instance.
      */
-    public PointerMapping(){
-        
-        
-        
-    }
+    public static final PointerMapping INSTANCE = new PointerMapping();
+
+    private PointerMapping() { }
 
-    /** {@inheritDoc} */
     @Override
     public Object cToJ(Object cVar, String signature, TypeMapping root) {
         if ( Pointer.class.isInstance(cVar)) return cVar;
-        return new Pointer((Long)cVar);
+        return new Pointer((long) cVar);
     }
 
-    /** {@inheritDoc} */
     @Override
     public Object jToC(Object jVar, String signature, TypeMapping root) {
         // After some difficult deliberation I've decided that it is 

src/main/java/ca/weblite/objc/mappers/ScalarMapping.java

@@ -10,8 +10,13 @@
  * @since 1.1
  */
 public class ScalarMapping implements TypeMapping {
-
-    /** {@inheritDoc} */
+    /**
+     * Singleton instance.
+     */
+    public static final ScalarMapping INSTANCE = new ScalarMapping();
+    
+    private ScalarMapping() { }
+    
     @Override
     public Object cToJ(Object cVar, String signature, TypeMapping root) {
         //System.out.println("C to J for signature "+signature);
@@ -27,14 +32,13 @@ public Object cToJ(Object cVar, String signature, TypeMapping root) {
                 case 'c':
                     return (byte) cObj;
                 case 'B':
-                    return cObj > 0L ? true:false;
+                    return cObj > 0L;
             }
         }
 
         return cVar;
     }
 
-    /** {@inheritDoc} */
     @Override
     public Object jToC(Object jVar, String signature, TypeMapping root) {
         return jVar;

src/main/java/ca/weblite/objc/mappers/StringMapping.java

@@ -1,24 +1,29 @@
 package ca.weblite.objc.mappers;
 
-import ca.weblite.objc.TypeMapping;
 import com.sun.jna.Pointer;
 
+import ca.weblite.objc.TypeMapping;
+
 /**
  * <p>StringMapping class.</p>
  *
  * @author shannah
  * @version $Id: $Id
  * @since 1.1
  */
-public class StringMapping implements TypeMapping{
-
-    /** {@inheritDoc} */
+public class StringMapping implements TypeMapping {
+    /**
+     * Singleton instance.
+     */
+    public static final StringMapping INSTANCE = new StringMapping();
+    
+    private StringMapping() { }
+    
     @Override
     public Object cToJ(Object cVar, String signature, TypeMapping root) {
         return new Pointer((Long)cVar).getString(0);
     }
 
-    /** {@inheritDoc} */
     @Override
     public Object jToC(Object jVar, String signature, TypeMapping root) {
         return jVar;

src/main/java/ca/weblite/objc/mappers/StructureMapping.java

@@ -10,14 +10,18 @@
  * @since 1.1
  */
 public class StructureMapping implements TypeMapping {
+    /**
+     * Singleton instance.
+     */
+    public static final StructureMapping INSTANCE = new StructureMapping();
 
-    /** {@inheritDoc} */
+    private StructureMapping() { }
+    
     @Override
     public Object cToJ(Object cVar, String signature, TypeMapping root) {
         return cVar;
     }
 
-    /** {@inheritDoc} */
     @Override
     public Object jToC(Object jVar, String signature, TypeMapping root) {
         return jVar;