Add NamedNumber utility

src/main/java/com/blibli/oss/common/helper/util/NamedNumber.java

@@ -0,0 +1,111 @@
+package com.blibli.oss.common.helper.util;
+
+import java.io.Serializable;
+
+/**
+ * Common base class for dynamic named number (enum like).
+ * Example:
+ * <pre>
+ * public final class HttpStatusCode extends NamedNumber<Integer, HttpStatusCode> {
+ *
+ *      public static final HttpStatusCode NOT_FOUND =
+ *          new HttpStatusCode(404, "Not found.");
+ *
+ *      public static final HttpStatusCode OK =
+ *          new HttpStatusCode(20, "Ok.");
+ *
+ *      public static final HttpStatusCode UNKNOWN =
+ *          new HttpStatusCode(0, "Unknown Http Status Code.");
+ *
+ *      public HttpStatusCode(Integer value, String name) {
+ *          super(value, name);
+ *      }
+ *
+ *      private static final Map<Integer, HttpStatusCode> registry
+ *          = new HashMap<>();
+ *
+ *      public static final HttpStatusCode register(final HttpStatusCode httpStatusCode) {
+ *          registry.put(httpStatusCode.getValue(), httpStatusCode);
+ *          return httpStatusCode;
+ *      }
+ *
+ *      public static final HttpStatusCode valueOf(final int rawValue) {
+ *          HttpStatusCode httpStatusCode = registry.get(rawValue);
+ *          if (httpStatusCode == null) {
+ *              return UNKNOWN;
+ *          }
+ *          return httpStatusCode;
+ *      }
+ *
+ *      static {
+ *          registry.put(NOT_FOUND.getValue(), NOT_FOUND);
+ *          registry.put(OK.getValue(), OK);
+ *          registry.put(UNKNOWN.getValue(), UNKNOWN);
+ *      }
+ *
+ *  }
+ *  </pre>
+ * @see Enum
+ * @see Number
+ * @author Ardika Rommy Sanjaya
+ * @since 0.0.1
+ * @param <T> number.
+ * @param <U> named number.
+ */
+public abstract class NamedNumber<T extends Number, U extends NamedNumber<T, ?>> implements Serializable {
+
+    private static final long serialVersionUID = -7754849362562086047L;
+
+    private final T value;
+    private final String name;
+
+    protected NamedNumber(T value, String name) {
+        this.value = value;
+        this.name = name;
+    }
+
+    /**
+     * Returns the number of this {@code NamedNumber} object.
+     * @return returns the number of this {@code NamedNumber} object.
+     */
+    public T getValue() {
+        return this.value;
+    }
+
+    /**
+     * Returns the name of this {@code NamedNumber} object.
+     * @return returns the name of this {@code NamedNumber} object.
+     */
+    public String getName() {
+        return this.name;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) {
+            return true;
+        }
+        if (obj.getClass() != this.getClass()) {
+            return false;
+        }
+        if (!(obj instanceof NamedNumber)) {
+            return false;
+        }
+        return this.value.equals(this.getClass().cast(obj).getValue());
+    }
+
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return new StringBuilder("[Value: ")
+                .append(this.value)
+                .append(", Name: ")
+                .append(this.name)
+                .append("]").toString();
+    }
+
+}

src/test/java/com/blibli/oss/common/helper/NamedNumberTest.java

@@ -0,0 +1,44 @@
+package com.blibli.oss.common.helper;
+
+import com.blibli.oss.common.helper.config.HttpStatusCode;
+import org.junit.Test;
+
+import static junit.framework.Assert.assertEquals;
+
+/**
+ * @author Ardika Rommy Sanjaya
+ */
+public class NamedNumberTest {
+
+    public static final int NOT_FOUND_CODE = 404;
+    public static final int UNKNOWN_CODE = 10000;
+    public static final int INTERNAL_SERVER_ERROR_CODE = 500;
+
+    @Test
+    public void found() {
+        HttpStatusCode httpStatusCode = HttpStatusCode.valueOf(NOT_FOUND_CODE);
+        assertEquals(HttpStatusCode.NOT_FOUND.getValue(), httpStatusCode.getValue());
+    }
+
+    @Test
+    public void notFound() {
+        HttpStatusCode httpStatusCode = HttpStatusCode.valueOf(UNKNOWN_CODE);
+        assertEquals(HttpStatusCode.UNKNOWN.getValue(), httpStatusCode.getValue());
+    }
+
+    @Test
+    public void registerNewCode() {
+        /**
+         * Register http status code.
+         */
+        HttpStatusCode httpStatusCode = new HttpStatusCode(INTERNAL_SERVER_ERROR_CODE, "Internal Server Error.r");
+        HttpStatusCode.register(httpStatusCode);
+
+        /**
+         * Test
+         */
+        HttpStatusCode internalServerError = HttpStatusCode.valueOf(INTERNAL_SERVER_ERROR_CODE);
+        assertEquals(httpStatusCode.getValue(), internalServerError.getValue());
+    }
+
+}

src/test/java/com/blibli/oss/common/helper/config/HttpStatusCode.java

@@ -0,0 +1,47 @@
+package com.blibli.oss.common.helper.config;
+
+import com.blibli.oss.common.helper.util.NamedNumber;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author Ardika Rommy Sanjaya
+ */
+public final class HttpStatusCode extends NamedNumber<Integer, HttpStatusCode> {
+
+    private static final Map<Integer, HttpStatusCode> registry
+            = new HashMap<>();
+
+    public static final HttpStatusCode NOT_FOUND =
+            new HttpStatusCode(404, "Not found.");
+
+    public static final HttpStatusCode OK =
+            new HttpStatusCode(20, "OK.");
+
+    public static final HttpStatusCode UNKNOWN =
+            new HttpStatusCode(0, "Unknown Http Status Code.");
+
+    public HttpStatusCode(Integer value, String name) {
+        super(value, name);
+    }
+
+    public static final HttpStatusCode register(final HttpStatusCode httpStatusCode) {
+        registry.put(httpStatusCode.getValue(), httpStatusCode);
+        return httpStatusCode;
+    }
+
+    public static final HttpStatusCode valueOf(final int rawValue) {
+        HttpStatusCode httpStatusCode = registry.get(rawValue);
+        if (httpStatusCode == null) {
+            return UNKNOWN;
+        }
+        return httpStatusCode;
+    }
+
+    static {
+        registry.put(NOT_FOUND.getValue(), NOT_FOUND);
+        registry.put(OK.getValue(), OK);
+        registry.put(UNKNOWN.getValue(), UNKNOWN);
+    }
+
+}