improve DeepCopy util class

scm-core/src/main/java/sonia/scm/io/DeepCopy.java

@@ -56,57 +56,41 @@ import java.io.ObjectOutputStream;
  * @since 1.29
  * @see <a href="http://javatechniques.com/blog/faster-deep-copies-of-java-objects" target="_blank">http://javatechniques.com/blog/faster-deep-copies-of-java-objects</a>
  */
-public final class DeepCopy
-{
+public final class DeepCopy {
 
+  private DeepCopy() {
+  }
+  
   /**
    * Returns a copy of the object, or null if the object cannot
    * be serialized.
    *
-   * @param orig
-   * @param <T>
+   * @param orig object to copy
+   * @param <T> type of object to copy
    *
-   * @return
+   * @return deep copy of object
    *
    * @throws IOException
    */
   @SuppressWarnings("unchecked")
-  public static <T> T copy(T orig) throws IOException
-  {
-    T obj = null;
-
-    Closer closer = Closer.create();
-
-    try
-    {
-
+  public static <T> T copy(T orig) throws IOException {
+    try (Closer closer = Closer.create()) {
       // Write the object out to a byte array
-      FastByteArrayOutputStream fbos =
-        closer.register(new FastByteArrayOutputStream());
-      ObjectOutputStream out = closer.register(new ObjectOutputStream(fbos));
-
-      out.writeObject(orig);
-      out.flush();
-      out.close();
+      FastByteArrayOutputStream fbos = closer.register(new FastByteArrayOutputStream());
+      try (ObjectOutputStream out = new ObjectOutputStream(fbos)) {
+        out.writeObject(orig);
+        out.flush();
+      }
 
       // Retrieve an input stream from the byte array and read
       // a copy of the object back in.
       // use ScmObjectInputStream to solve ClassNotFoundException
       // for plugin classes
-      ObjectInputStream in =
-        closer.register(new ScmObjectInputStream(fbos.getInputStream()));
-
-      obj = (T) in.readObject();
-    }
-    catch (Exception ex)
-    {
+      ObjectInputStream in = closer.register(new ScmObjectInputStream(fbos.getInputStream()));
+      
+      return (T) in.readObject();
+    } catch (ClassNotFoundException ex) {
       throw new IOException("could not copy object", ex);
     }
-    finally
-    {
-      closer.close();
-    }
-
-    return obj;
   }
 }

scm-core/src/test/java/sonia/scm/io/DeepCopyTest.java

@@ -45,23 +45,20 @@ import java.io.IOException;
 import java.io.Serializable;
 
 /**
- *
+ * Unit tests for {@link DeepCopy}.
+ * 
  * @author Sebastian Sdorra
  */
-public class DeepCopyTest
-{
+public class DeepCopyTest {
 
   /**
-   * Method description
-   *
+   * Tests {@link DeepCopy#copy(Object)}.
    *
    * @throws IOException
    */
   @Test
-  public void testDeepCopy() throws IOException
-  {
-    Person orig = new Person("Tricia", "McMillan",
-                    new Address("Magrathea", "Mainstreet 3"));
+  public void testDeepCopy() throws IOException {
+    Person orig = new Person("Tricia", "McMillan", new Address("Magrathea", "Mainstreet 3"));
     Person copy = DeepCopy.copy(orig);
 
     assertNotSame(orig, copy);
@@ -69,73 +66,35 @@ public class DeepCopyTest
   }
 
   /**
-   * Method description
-   *
+   * Tests {@link DeepCopy#copy(Object)} with a non serializable object.
    *
    * @throws IOException
    */
   @Test(expected = IOException.class)
-  public void testDeepCopyNonSerializable() throws IOException
-  {
+  public void testDeepCopyNonSerializable() throws IOException {
     DeepCopy.copy(new NonSerializable());
   }
 
   //~--- inner classes --------------------------------------------------------
 
-  /**
-   * Class description
-   *
-   *
-   * @version        Enter version here..., 14/03/08
-   * @author         Enter your name here...
-   */
-  private static class Address implements Serializable
-  {
+  private static class Address implements Serializable {
 
-    /** Field description */
     private static final long serialVersionUID = 3200816222378286310L;
-
-    //~--- constructors -------------------------------------------------------
-
-    /**
-     * Constructs ...
-     *
-     */
+    
     public Address() {}
 
-    /**
-     * Constructs ...
-     *
-     *
-     * @param city
-     * @param street
-     */
-    public Address(String city, String street)
-    {
+    public Address(String city, String street) {
       this.city = city;
       this.street = street;
     }
 
-    //~--- methods ------------------------------------------------------------
-
-    /**
-     * Method description
-     *
-     *
-     * @param obj
-     *
-     * @return
-     */
     @Override
-    public boolean equals(Object obj)
-    {
-      if (obj == null)
-      {
+    public boolean equals(Object obj) {
+      if (obj == null) {
         return false;
       }
 
-      if (getClass() != obj.getClass())
-      {
+      if (getClass() != obj.getClass()) {
         return false;
       }
 
@@ -144,94 +103,40 @@ public class DeepCopyTest
       return Objects.equal(city, other.city)
         && Objects.equal(street, other.street);
     }
-
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
+    
     @Override
-    public int hashCode()
-    {
+    public int hashCode() {
       return Objects.hashCode(city, street);
     }
 
     //~--- get methods --------------------------------------------------------
 
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
-    public String getCity()
-    {
+    public String getCity() {
       return city;
     }
 
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
-    public String getStreet()
-    {
+    public String getStreet() {
       return street;
     }
 
     //~--- fields -------------------------------------------------------------
 
-    /** Field description */
     private String city;
 
-    /** Field description */
     private String street;
   }
 
-
-  /**
-   * Class description
-   *
-   *
-   * @version        Enter version here..., 14/03/08
-   * @author         Enter your name here...    
-   */
   private static class NonSerializable {}
 
+  private static class Person implements Serializable {
 
-  /**
-   * Class description
-   *
-   *
-   * @version        Enter version here..., 14/03/08
-   * @author         Enter your name here...
-   */
-  private static class Person implements Serializable
-  {
-
-    /** Field description */
     private static final long serialVersionUID = -2098386757802626539L;
 
     //~--- constructors -------------------------------------------------------
 
-    /**
-     * Constructs ...
-     *
-     */
     public Person() {}
 
-    /**
-     * Constructs ...
-     *
-     *
-     * @param firstname
-     * @param lastname
-     * @param address
-     */
-    public Person(String firstname, String lastname, Address address)
-    {
+    public Person(String firstname, String lastname, Address address) {
       this.firstname = firstname;
       this.lastname = lastname;
       this.address = address;
@@ -239,24 +144,13 @@ public class DeepCopyTest
 
     //~--- methods ------------------------------------------------------------
 
-    /**
-     * Method description
-     *
-     *
-     * @param obj
-     *
-     * @return
-     */
     @Override
-    public boolean equals(Object obj)
-    {
-      if (obj == null)
-      {
+    public boolean equals(Object obj) {
+      if (obj == null) {
         return false;
       }
 
-      if (getClass() != obj.getClass())
-      {
+      if (getClass() != obj.getClass()) {
         return false;
       }
 
@@ -267,62 +161,31 @@ public class DeepCopyTest
         && Objects.equal(address, other.address);
     }
 
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
     @Override
-    public int hashCode()
-    {
+    public int hashCode() {
       return Objects.hashCode(firstname, lastname, address);
     }
 
     //~--- get methods --------------------------------------------------------
 
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
-    public Address getAddress()
-    {
+    public Address getAddress() {
       return address;
     }
-
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
-    public String getFirstname()
-    {
+    
+    public String getFirstname() {
       return firstname;
     }
 
-    /**
-     * Method description
-     *
-     *
-     * @return
-     */
-    public String getLastname()
-    {
+    public String getLastname() {
       return lastname;
     }
 
     //~--- fields -------------------------------------------------------------
 
-    /** Field description */
     private Address address;
-
-    /** Field description */
+    
     private String firstname;
 
-    /** Field description */
     private String lastname;
   }
 }