#181: added Id

#177: improved
#163: improved

mmm-util-core/src/main/java/net/sf/mmm/util/lang/api/Id.java

@@ -0,0 +1,55 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package net.sf.mmm.util.lang.api;
+
+/**
+ * This is the interface for an ID that uniquely identifies an <em>entity</em> of a particular type.<br>
+ * An {@link Id} is build out of the following parts:
+ * <ul>
+ * <li>{@link #getId() object-id} - the ID that identifies the entity and is unique for a specific {@link #getType()
+ * type}.</li>
+ * <li>{@link #getType() type} - is the ID of the type of the identified entity.</li>
+ * <li>{@link #getRevision() revision} - the optional {@link #getRevision() revision} of the entity.</li>
+ * </ul>
+ * Just like the {@link #getId() primary key} the {@link #getRevision() revision} and {@link #getType() type} of an
+ * object do not change. This allows to create an instance of the identified object without additional costs (e.g.
+ * database lookup) by a dynamic proxy using lazy loading.<br>
+ * An {@link Id} has a compact {@link #toString() string representation} that can be converted back to an {@link Id}.
+ * Therefore, the implementation shall provide a {@link String}-arg constructor and a static {@code valueOf(String)}
+ * method.
+ *
+ * @param <E> the generic type of the identified entity.
+ *
+ * @see net.sf.mmm.util.lang.base.SimpleId
+ * @author hohwille
+ * @since 7.1.0
+ */
+public interface Id<E> extends Datatype {
+
+  /**
+   * @return the the <em>primary key</em> of the <em>entity</em>. It is only unique for a particular {@link #getType()
+   *         type} of an <em>entity</em>.
+   */
+  long getId();
+
+  /**
+   * @return the {@link Class} reflecting the <em>type</em> of the referenced <em>entity</em>.
+   */
+  Class<E> getType();
+
+  /**
+   * @return the optional revision of the <em>entity</em> referenced by this {@link Id} or {@code null} for the latest
+   *         revision. In case entities of this {@link #getType() type} will not be revision controlled, this method
+   *         will always return {@code null}.
+   */
+  Number getRevision();
+
+  /**
+   * @return the {@link String} representation of this {@link Id}. Will consist of {@link #getId() object-id},
+   *         {@link #getType() type} and {@link #getRevision() revision} separated with a specific separator. Segments
+   *         that are {@code null} will typically be omitted in the {@link String} representation.
+   */
+  @Override
+  String toString();
+
+}

mmm-util-core/src/main/java/net/sf/mmm/util/lang/base/AbstractId.java

@@ -0,0 +1,128 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package net.sf.mmm.util.lang.base;
+
+import java.util.Objects;
+
+import net.sf.mmm.util.lang.api.Id;
+
+/**
+ * This is the abstract base implementation of {@link Id}.
+ *
+ * @param <E> the generic type of the identified entity.
+ *
+ * @author hohwille
+ * @since 7.1.0
+ */
+public abstract class AbstractId<E> implements Id<E> {
+
+  private long objectId;
+
+  private Number revision;
+
+  private Class<E> type;
+
+  /**
+   * The constructor.
+   */
+  protected AbstractId() {
+    super();
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param type - see {@link #getType()}.
+   * @param objectId - see {@link #getId()}.
+   */
+  public AbstractId(Class<E> type, long objectId) {
+    this(type, objectId, null);
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param type - see {@link #getType()}.
+   * @param objectId - see {@link #getId()}.
+   * @param revision - see {@link #getRevision()}.
+   */
+  public AbstractId(Class<E> type, long objectId, Number revision) {
+    super();
+    this.type = type;
+    this.objectId = objectId;
+    this.revision = revision;
+  }
+
+  @Override
+  public long getId() {
+
+    return this.objectId;
+  }
+
+  @Override
+  public Class<E> getType() {
+
+    return this.type;
+  }
+
+  @Override
+  public Number getRevision() {
+
+    return this.revision;
+  }
+
+  @Override
+  public final int hashCode() {
+
+    return Objects.hash(Long.valueOf(this.objectId), this.type, this.revision);
+  }
+
+  @Override
+  public final boolean equals(Object obj) {
+
+    if (obj == this) {
+      return true;
+    }
+    if ((obj == null) || !(obj instanceof AbstractId)) {
+      return false;
+    }
+    AbstractId<?> other = (AbstractId<?>) obj;
+    if (this.objectId != other.objectId) {
+      return false;
+    }
+    if (!Objects.equals(this.type, other.type)) {
+      return false;
+    }
+    if (!Objects.equals(this.revision, other.revision)) {
+      return false;
+    }
+    return true;
+  }
+
+  @Override
+  public String toString() {
+
+    StringBuilder buffer = new StringBuilder(32);
+    toString(buffer);
+    return buffer.toString();
+  }
+
+  /**
+   * @see #toString()
+   * @param buffer the {@link StringBuilder} where to {@link StringBuilder#append(CharSequence) append} the string
+   *        representation to.
+   */
+  protected void toString(StringBuilder buffer) {
+
+    if (this.type != null) {
+      buffer.append(this.type.getSimpleName());
+      buffer.append(':');
+    }
+    buffer.append(this.objectId);
+    if (this.revision != null) {
+      buffer.append(':');
+      buffer.append(this.revision);
+    }
+  }
+
+}

mmm-util-core/src/main/java/net/sf/mmm/util/lang/base/SimpleId.java

@@ -0,0 +1,95 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package net.sf.mmm.util.lang.base;
+
+import javax.persistence.Id;
+
+/**
+ * This is a simple implementation of {@link Id}.
+ *
+ * @param <E> the generic type of the identified entity.
+ *
+ * @author hohwille
+ * @since 7.1.0
+ */
+public class SimpleId<E> extends AbstractId<E> {
+
+  /**
+   * The constructor.
+   */
+  protected SimpleId() {
+    super();
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param type - see {@link #getType()}.
+   * @param objectId - see {@link #getId()}.
+   */
+  public SimpleId(Class<E> type, long objectId) {
+    this(type, objectId, null);
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param type - see {@link #getType()}.
+   * @param objectId - see {@link #getId()}.
+   * @param revision - see {@link #getRevision()}.
+   */
+  public SimpleId(Class<E> type, long objectId, Number revision) {
+    super(type, objectId, revision);
+  }
+
+  /**
+   * @param <E> the generic type of the identified entity.
+   * @param type - see {@link #getType()}.
+   * @param id - see {@link #getId()}.
+   * @return a new instance of {@link SimpleId}.
+   */
+  public static <E> SimpleId<E> valueOf(Class<E> type, Long id) {
+
+    return valueOf(type, id, null);
+  }
+
+  /**
+   * @param <E> the generic type of the identified entity.
+   * @param type - see {@link #getType()}.
+   * @param id - see {@link #getId()}.
+   * @param revision - see {@link #getRevision()}.
+   * @return a new instance of {@link SimpleId}.
+   */
+  public static <E> SimpleId<E> valueOf(Class<E> type, Long id, Number revision) {
+
+    if (id == null) {
+      return null;
+    } else {
+      return valueOf(type, id.longValue(), revision);
+    }
+  }
+
+  /**
+   * @param <E> the generic type of the identified entity.
+   * @param type - see {@link #getType()}.
+   * @param id - see {@link #getId()}.
+   * @return a new instance of {@link SimpleId}.
+   */
+  public static <E> SimpleId<E> valueOf(Class<E> type, long id) {
+
+    return valueOf(type, id, null);
+  }
+
+  /**
+   * @param <E> the generic type of the identified entity.
+   * @param type - see {@link #getType()}.
+   * @param id - see {@link #getId()}.
+   * @param revision - see {@link #getRevision()}.
+   * @return a new instance of {@link SimpleId}.
+   */
+  public static <E> SimpleId<E> valueOf(Class<E> type, long id, Number revision) {
+
+    return new SimpleId<>(type, id, revision);
+  }
+
+}

mmm-util-core/src/main/java/net/sf/mmm/util/lang/base/datatype/adapter/jpa/SimpleIdAttributeConverter.java

@@ -0,0 +1,44 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package net.sf.mmm.util.lang.base.datatype.adapter.jpa;
+
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+
+import net.sf.mmm.util.lang.base.SimpleId;
+
+/**
+ * This is the implementation of {@link AttributeConverter} for {@link SimpleId}.
+ *
+ * @author Joerg Hohwiller (hohwille at users.sourceforge.net)
+ * @since 6.0.0
+ */
+@SuppressWarnings("rawtypes")
+@Converter(autoApply = true)
+// https://hibernate.atlassian.net/browse/HHH-8854
+public class SimpleIdAttributeConverter implements AttributeConverter<SimpleId, Long> {
+
+  /**
+   * The constructor.
+   */
+  public SimpleIdAttributeConverter() {
+
+    super();
+  }
+
+  @Override
+  public SimpleId convertToEntityAttribute(Long value) {
+
+    return SimpleId.valueOf(null, value);
+  }
+
+  @Override
+  public Long convertToDatabaseColumn(SimpleId datatype) {
+
+    if (datatype == null) {
+      return null;
+    }
+    return Long.valueOf(datatype.getId());
+  }
+
+}

mmm-util-property/src/main/java/net/sf/mmm/util/bean/api/BeanPrototypeBuilder.java

@@ -39,6 +39,24 @@ public interface BeanPrototypeBuilder extends AbstractBeanFactory {
    */
   Bean getPrototype(String qualifiedName);
 
+  /**
+   * Creates a {@link BeanAccess#isVirtual() virtual} prototype that allows dynamic beans at runtime (without an
+   * corresponding sub-interface existing as Java code).
+   *
+   * @see BeanFactory#createPrototype(Class)
+   *
+   * @param <BEAN> the generic type of the {@link Bean}.
+   * @param prototype the main prototype of the {@link Bean}.
+   * @param dynamic the {@link BeanAccess#isDynamic() dynamic flag} of the {@link Bean}.
+   * @param name the explicit {@link BeanAccess#getSimpleName() name} of the {@link Bean}.
+   * @param superBeanPrototypes the additional prototypes of the {@link Bean}s (mixins) that will also be inherited from
+   *        the prototype to create in addition to the given {@code prototype}. They have to be
+   *        {@link #getPrototype(Bean) prototypes}. The prototype to create must not result in cyclic inheritance or
+   *        inconsistent properties in case of multi-inheritance.
+   * @return the prototype instance of the specified {@link Bean}.
+   */
+  <BEAN extends Bean> BEAN createPrototype(BEAN prototype, String name, Bean... superBeanPrototypes);
+
   /**
    * Creates a {@link BeanAccess#isVirtual() virtual} prototype that allows dynamic beans at runtime (without an
    * corresponding sub-interface existing as Java code).
@@ -55,6 +73,10 @@ public interface BeanPrototypeBuilder extends AbstractBeanFactory {
    *        or inconsistent properties in case of multi-inheritance.
    * @return the prototype instance of the specified {@link Bean}.
    */
-  <BEAN extends Bean> BEAN createPrototype(Class<BEAN> type, String name, Bean... superBeanPrototypes);
+  default <BEAN extends Bean> BEAN createPrototype(Class<BEAN> type, String name, Bean... superBeanPrototypes) {
+
+    BEAN superPrototypeBean = getOrCreatePrototype(type);
+    return createPrototype(superPrototypeBean, name, superBeanPrototypes);
+  }
 
 }

mmm-util-property/src/main/java/net/sf/mmm/util/bean/api/Entity.java

@@ -2,6 +2,8 @@
  * http://www.apache.org/licenses/LICENSE-2.0 */
 package net.sf.mmm.util.bean.api;
 
+import net.sf.mmm.util.lang.api.Id;
+
 /**
  * This is the interface for an entity that may be loaded from or saved to a database. Typically you may want to use
  * {@link EntityBean} but for legacy technologies such as JPA you have to use standard Java Beans that can directly
@@ -11,11 +13,10 @@
  * <li>A {@link #getVersion() version}.</li>
  * </ul>
  *
- * @param <ID> the generic type of the {@link #getId() primary key}.
  * @author hohwille
  * @since 8.0.0
  */
-public interface Entity<ID> {
+public interface Entity {
 
   /** {@link net.sf.mmm.util.property.api.WritableProperty#getName() Property name} of {@link #getId() ID}. */
   String PROPERTY_NAME_ID = "Id";
@@ -27,12 +28,12 @@ public interface Entity<ID> {
    * @return the unique ID (primary key) of this entity or {@code null} if not available (e.g. entity is not
    *         persistent).
    */
-  ID getId();
+  Id<?> getId();
 
   /**
    * @param id the new {@link #getId() ID}.
    */
-  void setId(ID id);
+  void setId(Id<?> id);
 
   /**
    * @return the {@code version} of this entity. Whenever the {@link Entity} gets updated (a modification is saved and