Введение в API Java OrientDB

@BeforeClass
public static void setup() {
    String orientDBFolder = System.getenv("ORIENTDB_HOME");
    graph = new OrientGraphNoTx("plocal:" + orientDBFolder +
      "/databases/exampleDB", "admin", "admin");
}

@BeforeClass
public static void init() {
    graph.createVertexType("Article");

    OrientVertexType writerType
      = graph.createVertexType("Writer");
    writerType.setStrictMode(true);
    writerType.createProperty("firstName", OType.STRING);
    // ...

    OrientVertexType authorType
      = graph.createVertexType("Author", "Writer");
    authorType.createProperty("level", OType.INTEGER).setMax("3");

    OrientVertexType editorType
      = graph.createVertexType("Editor", "Writer");
    editorType.createProperty("level", OType.INTEGER).setMin("3");

    Vertex vEditor = graph.addVertex("class:Editor");
    vEditor.setProperty("firstName", "Maxim");
    // ...

    Vertex vAuthor = graph.addVertex("class:Author");
    vAuthor.setProperty("firstName", "Jerome");
    // ...

    Vertex vArticle = graph.addVertex("class:Article");
    vArticle.setProperty("title", "Introduction to ...");
    // ...

    graph.addEdge(null, vAuthor, vEditor, "has");
    graph.addEdge(null, vAuthor, vArticle, "wrote");
}

long size = graph.countVertices();

@Test
public void givenexampleDB_checkWeHaveTwoWriters() {
    long size = graph.countVertices("Writer");

    assertEquals(2, size);
}

Iterable writers = graph.getVerticesOfClass("Writer");

@Test
public void givenexampleDB_getEditorWithLevelSeven() {
    String onlyEditor = "";
    for(Vertex v : graph.getVertices("Editor.level", 7)) {
        onlyEditor = v.getProperty("firstName").toString();
    }

    assertEquals("Maxim", onlyEditor);
}

@BeforeClass
public static void setup() {
    String orientDBFolder = System.getenv("ORIENTDB_HOME");
    db = new ODatabaseDocumentTx("plocal:"
      + orientDBFolder + "/databases/exampleDBTwo")
      .open("admin", "admin");
}

@Test
public void givenDB_whenSavingDocument_thenClassIsAutoCreated() {
    ODocument doc = new ODocument("Author");
    doc.field("name", "Paul");
    doc.save();

    assertEquals("Author", doc.getSchemaClass().getName());
}

long size = db.countClass("Author");

@Test
public void givenDB_whenSavingAuthors_thenWeGetOnesWithLevelSeven() {
    for (ODocument author : db.browseClass("Author")) author.delete();

    ODocument authorOne = new ODocument("Author");
    authorOne.field("firstName", "Leo");
    authorOne.field("level", 7);
    authorOne.save();

    ODocument authorTwo = new ODocument("Author");
    authorTwo.field("firstName", "Lucien");
    authorTwo.field("level", 9);
    authorTwo.save();

    List result = db.query(
      new OSQLSynchQuery("select * from Author where level = 7"));

    assertEquals(1, result.size());
}

for (ODocument author : db.browseClass("Author")) {
    author.delete();
}