使用Java驱动操作ArangoDB

前面说过怎样使用 ArangoDB 的 Web，Shell 和 Restful API 来操作数据库，今天看一下怎样使用Java语言来操作ArangoDB数据库。

首先创建一个Maven工程，添加 ArangoDB 的 Java 驱动库

        <dependency>
            <groupId>com.arangodb</groupId>
            <artifactId>arangodb-java-driver</artifactId>
            <version>6.5.0</version>
        </dependency>

完整的 pom.xml 文件内容如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>my.arangodbstudy</groupId>
    <artifactId>arangodbstudy</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>arangodbstudy</name>
    <url>http://maven.apache.org</url>

    <dependencies>
        <dependency>
            <groupId>com.arangodb</groupId>
            <artifactId>arangodb-java-driver</artifactId>
            <version>6.5.0</version>
        </dependency>
        
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>8</source>
                    <target>8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

下面写了一个简单的 Java 类，其中包含了一些常用的操作，如：创建/关闭连接，数据库操作，集合操作和文档操作等。

package my.arangodbstudy;

import com.arangodb.ArangoCollection;
import com.arangodb.ArangoDB;
import com.arangodb.ArangoDatabase;
import com.arangodb.entity.BaseDocument;
import com.arangodb.entity.CollectionEntity;
import com.arangodb.entity.DocumentCreateEntity;

import java.util.Collection;

public class SimpleTest {

    private static final String DB_HOST = "localhost";
    private static final int DB_PORT = 8529;
    private static final String DB_USERNAME = "root";
    private static final String DB_PASSWORD = "<password>";
    private static final String DB_NAME = "mydb";
    private static final String COLLECTION_NAME = "users";

    public static void main(String[] args) {
        // 构造ArangoDB实例
        ArangoDB arangoDB = new ArangoDB.Builder()
                .host(DB_HOST, DB_PORT)
                .user(DB_USERNAME)
                .password(DB_PASSWORD)
                .build();

        // 判断数据库存在，如果存在删除
        if (arangoDB.db(DB_NAME).exists()) {
            arangoDB.db(DB_NAME).drop();
        }

        // 创建数据库
        arangoDB.createDatabase(DB_NAME);
        System.out.println("arangodb databases: " + arangoDB.getDatabases());

        // 获取刚才创建的数据库
        ArangoDatabase db = arangoDB.db(DB_NAME);

        // 迭代打印数据库中的集合
        Collection<CollectionEntity> collectionEntities = db.getCollections();
        for (CollectionEntity collectionEntity: collectionEntities) {
            System.out.println(collectionEntity.getName());
        }

        // 创建集合
        CollectionEntity collectionEntity = db.createCollection(COLLECTION_NAME);
        System.out.println("collection name: " + collectionEntity.getName());

        // 获取创建的集合
        ArangoCollection collection = db.collection(COLLECTION_NAME);

        // 创建文档对象
        BaseDocument document = new BaseDocument();
        document.addAttribute("name", "user");
        document.addAttribute("age", 10);
        document.addAttribute("sex", 1);

        // 写入数据
        DocumentCreateEntity documentCreateEntity = collection.insertDocument(document);
        System.out.println("collection count: " + collection.count().getCount());

        // 查询
        document = collection.getDocument(documentCreateEntity.getKey(), BaseDocument.class);
        System.out.println("document: " + document);

        // 更新文档
        document.updateAttribute("sex", 0);
        collection.updateDocument(documentCreateEntity.getKey(), document);
        document = collection.getDocument(documentCreateEntity.getKey(), BaseDocument.class);
        System.out.println("document: " + document);

        // 删除文档
        collection.deleteDocument(documentCreateEntity.getKey());
        document = collection.getDocument(documentCreateEntity.getKey(), BaseDocument.class);
        System.out.println("document: " + document);

        // 删除集合
        collection.drop();

        // 删除数据库
        db.drop();

        // shutdown ArangoDB
        arangoDB.shutdown();
    }
}

另外，在ArangoDB中，也可以使用AQL来执行一些查询操作获取需要的集合，比如：

package my.arangodbstudy;

import com.arangodb.ArangoCollection;
import com.arangodb.ArangoCursor;
import com.arangodb.ArangoDB;
import com.arangodb.ArangoDatabase;
import com.arangodb.entity.BaseDocument;
import com.arangodb.entity.CollectionEntity;
import com.arangodb.entity.DocumentCreateEntity;
import com.arangodb.util.MapBuilder;

import java.util.Collection;
import java.util.Map;

public class SimpleAQLTest {

    private static final String DB_HOST = "localhost";
    private static final int DB_PORT = 8529;
    private static final String DB_USERNAME = "root";
    private static final String DB_PASSWORD = "<password>";
    private static final String DB_NAME = "mydb";
    private static final String COLLECTION_NAME = "users";

    public static void main(String[] args) {
        // 构造ArangoDB实例
        ArangoDB arangoDB = new ArangoDB.Builder()
                .host(DB_HOST, DB_PORT)
                .user(DB_USERNAME)
                .password(DB_PASSWORD)
                .build();

        // 判断数据库存在，如果存在删除
        if (arangoDB.db(DB_NAME).exists()) {
            arangoDB.db(DB_NAME).drop();
        }

        // 创建数据库
        arangoDB.createDatabase(DB_NAME);
        System.out.println("arangodb databases: " + arangoDB.getDatabases());

        // 获取刚才创建的数据库
        ArangoDatabase db = arangoDB.db(DB_NAME);

        // 创建集合
        CollectionEntity collectionEntity = db.createCollection(COLLECTION_NAME);
        System.out.println("collection name: " + collectionEntity.getName());

        // 获取创建的集合
        ArangoCollection collection = db.collection(COLLECTION_NAME);

        // 创建文档对象并写入
        for (int i = 0; i < 10; i++) {
            BaseDocument document = new BaseDocument();
            document.addAttribute("name", "user_" + i);
            document.addAttribute("age", 10 + i);
            document.addAttribute("sex", 1);
            collection.insertDocument(document);
        }
        System.out.println("collection count: " + collection.count().getCount());

        // 使用AQL查询文档
        String query = "FOR user IN " + COLLECTION_NAME +
                " FILTER user.name == @name || user.age >= @age " +
                " RETURN user";
        Map<String, Object> params = new MapBuilder()
                .put("name", "user_0")
                .put("age", 15)
                .get();
        ArangoCursor<BaseDocument> cursor = db.query(query, params, null, BaseDocument.class);
        cursor.forEachRemaining(document -> {
            System.out.println("document: " + document);
        });

        // 删除集合
        collection.drop();

        // 删除数据库
        db.drop();

        // shutdown ArangoDB
        arangoDB.shutdown();
    }
}