add createId methods in GraphFactory (#45)

computer-api/src/main/java/com/baidu/hugegraph/computer/core/graph/GraphFactory.java

@@ -21,6 +21,7 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.UUID;
 
 import com.baidu.hugegraph.computer.core.graph.edge.Edge;
 import com.baidu.hugegraph.computer.core.graph.edge.Edges;
@@ -31,6 +32,12 @@
 
 public interface GraphFactory {
 
+    Id createId(long id);
+
+    Id createId(String id);
+
+    Id createId(UUID id);
+
     Vertex createVertex();
 
     <V extends Value<?>> Vertex createVertex(Id id, V value);

computer-core/src/main/java/com/baidu/hugegraph/computer/core/graph/BuiltinGraphFactory.java

@@ -23,6 +23,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.UUID;
 
 import com.baidu.hugegraph.computer.core.config.ComputerOptions;
 import com.baidu.hugegraph.computer.core.config.Config;
@@ -31,6 +32,9 @@
 import com.baidu.hugegraph.computer.core.graph.edge.Edge;
 import com.baidu.hugegraph.computer.core.graph.edge.Edges;
 import com.baidu.hugegraph.computer.core.graph.id.Id;
+import com.baidu.hugegraph.computer.core.graph.id.LongId;
+import com.baidu.hugegraph.computer.core.graph.id.Utf8Id;
+import com.baidu.hugegraph.computer.core.graph.id.UuidId;
 import com.baidu.hugegraph.computer.core.graph.properties.DefaultProperties;
 import com.baidu.hugegraph.computer.core.graph.properties.Properties;
 import com.baidu.hugegraph.computer.core.graph.value.Value;
@@ -45,6 +49,21 @@ public BuiltinGraphFactory(Config config) {
         this.config = config;
     }
 
+    @Override
+    public Id createId(long id) {
+        return new LongId(id);
+    }
+
+    @Override
+    public Id createId(String id) {
+        return new Utf8Id(id);
+    }
+
+    @Override
+    public Id createId(UUID id) {
+        return new UuidId(id);
+    }
+
     @Override
     public Vertex createVertex() {
         return new DefaultVertex(this);

computer-test/src/main/java/com/baidu/hugegraph/computer/core/graph/BuiltinGraphFactoryTest.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.baidu.hugegraph.computer.core.graph;
+
+import java.util.UUID;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.baidu.hugegraph.computer.core.UnitTestBase;
+import com.baidu.hugegraph.computer.core.graph.id.Id;
+import com.baidu.hugegraph.computer.core.graph.id.IdType;
+import com.baidu.hugegraph.computer.core.graph.id.LongId;
+import com.baidu.hugegraph.computer.core.graph.id.Utf8Id;
+import com.baidu.hugegraph.computer.core.graph.id.UuidId;
+
+public class BuiltinGraphFactoryTest extends UnitTestBase {
+
+    @Test
+    public void testCreateLongId() {
+        long value = 1L;
+        GraphFactory graphFactory = graphFactory();
+        Id id = graphFactory.createId(value);
+        Assert.assertEquals(IdType.LONG, id.type());
+        Assert.assertEquals(new LongId(value), id);
+    }
+
+    @Test
+    public void testCreateUtf8Id() {
+        String value = "John";
+        GraphFactory graphFactory = graphFactory();
+        Id id = graphFactory.createId(value);
+        Assert.assertEquals(IdType.UTF8, id.type());
+        Assert.assertEquals(new Utf8Id(value), id);
+    }
+
+    @Test
+    public void testCreateUuidId() {
+        UUID uuid = UUID.randomUUID();
+        GraphFactory graphFactory = graphFactory();
+        Id id = graphFactory.createId(uuid);
+        Assert.assertEquals(IdType.UUID, id.type());
+        Assert.assertEquals(new UuidId(uuid), id);
+    }
+}

computer-test/src/main/java/com/baidu/hugegraph/computer/core/graph/GraphTestSuite.java

@@ -63,6 +63,7 @@
     ListValueTest.class,
     ValueTypeTest.class,
     BuiltinValueFactoryTest.class,
+    BuiltinGraphFactoryTest.class,
     ContainerInfoTest.class,
     PartitionStatTest.class,
     HashPartitionerTest.class,