ROASTER-101: Added SerialVersionUIDComputer

api/src/main/java/org/jboss/forge/roaster/model/util/SerialVersionUIDComputer.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.roaster.model.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.Serializable;
+import java.lang.reflect.Modifier;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.List;
+
+import org.jboss.forge.roaster.model.source.JavaClassSource;
+import org.jboss.forge.roaster.model.source.MemberSource;
+
+/**
+ * Computes the SerialVersion UID value
+ * 
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ */
+public class SerialVersionUIDComputer
+{
+
+   private SerialVersionUIDComputer()
+   {
+   }
+
+   /**
+    * This is not the official algorithm as defined in the JLS spec, but it is close
+    * 
+    * @see {@link java.io.ObjectStreamClass#getSerialVersionUID()}
+    * @return the computed serialVersionUID value
+    */
+   public static long compute(JavaClassSource source)
+   {
+      if (!source.hasInterface(Serializable.class))
+      {
+         return 0L;
+      }
+      try
+      {
+         ByteArrayOutputStream bout = new ByteArrayOutputStream();
+         DataOutputStream dout = new DataOutputStream(bout);
+
+         dout.writeUTF(source.getQualifiedName());
+         int classMods = 0;
+         if (source.isPublic())
+         {
+            classMods |= Modifier.PUBLIC;
+         }
+         if (source.isFinal())
+         {
+            classMods |= Modifier.FINAL;
+         }
+         if (source.isInterface())
+         {
+            classMods |= Modifier.INTERFACE;
+         }
+         if (source.isAbstract())
+         {
+            classMods |= Modifier.ABSTRACT;
+         }
+         dout.writeInt(classMods);
+
+         List<MemberSource<JavaClassSource, ?>> members = source.getMembers();
+         for (MemberSource<JavaClassSource, ?> member : members)
+         {
+            if (!member.isPrivate())
+            {
+               dout.writeUTF(member.getName());
+               dout.writeUTF(member.toString().replace('/', '.'));
+            }
+         }
+         dout.flush();
+         System.out.println(bout);
+         MessageDigest md = MessageDigest.getInstance("SHA");
+         byte[] hashBytes = md.digest(bout.toByteArray());
+         long hash = 0;
+         for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--)
+         {
+            hash = (hash << 8) | (hashBytes[i] & 0xFF);
+         }
+         return hash;
+      }
+      catch (IOException ex)
+      {
+         throw new InternalError(ex);
+      }
+      catch (NoSuchAlgorithmException ex)
+      {
+         throw new SecurityException(ex.getMessage());
+      }
+   }
+
+}

tests/src/test/java/org/jboss/forge/test/roaster/model/util/SerialVersionUIDComputerTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2016 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.test.roaster.model.util;
+
+import java.io.Serializable;
+
+import org.jboss.forge.roaster.Roaster;
+import org.jboss.forge.roaster.model.source.JavaClassSource;
+import org.jboss.forge.roaster.model.util.SerialVersionUIDComputer;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ *
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ */
+public class SerialVersionUIDComputerTest
+{
+
+   @Test
+   public void testNonSerializableSerialVersionUID() throws Exception
+   {
+      JavaClassSource type = Roaster.create(JavaClassSource.class).setName("Foo");
+      type.addMethod().setName("foo");
+      type.addField().setType(String.class).setName("bar");
+      Assert.assertEquals(0, SerialVersionUIDComputer.compute(type));
+   }
+
+   @Test
+   public void testSerialVersionUID1() throws Exception
+   {
+      JavaClassSource type = Roaster.create(JavaClassSource.class).setName("Foo").addInterface(Serializable.class);
+      type.addMethod().setName("foo");
+      type.addField().setType(String.class).setName("bar");
+      long result = 8297639620252560729L;
+      Assert.assertEquals(result, SerialVersionUIDComputer.compute(type));
+   }
+
+   @Test
+   public void testSerialVersionUID2() throws Exception
+   {
+      JavaClassSource type = Roaster.create(JavaClassSource.class).setName("Bar").addInterface(Serializable.class);
+      type.addMethod().setName("foo");
+      type.addField().setType(String.class).setName("bar");
+      long result = 6931690417956417438L;
+      Assert.assertEquals(result, SerialVersionUIDComputer.compute(type));
+   }
+}