1. Intellij IDEA创建gradle工程

New -> Project -> Gradle ，勾选Java，选择Next；

GroupId和ArtifactId随便填，选择Next；

勾选“Create directories for empty content roots automatically”，选择“Use local gradle distribution”填入本地gradle路径，选择Next；

点击Finish。

创建完工程后，等工程自动刷新完。

刷新完后就能看到工程目录结构，自动创建了src/main/java

2. 添加mongodb库

修改build.gradle

dependencies {
    compile group: 'org.mongodb', name: 'mongo-java-driver', version: '3.4.1'
}

刷新gradle，可以在External Libraies中看到mongo-java-driver

3.代码连接mongodb

在src/main/java下创建一个package并添加一个class

public class MongoExample {
    public static void main(String args[]) {
        System.out.println("helloworld");
        try {
            MongoClient mongoClient = new MongoClient("localhost", 27017);
            MongoDatabase mongoDatabase = mongoClient.getDatabase("hello");
            /* Add collection */
            MongoCollection<Document> mongoCollection = mongoDatabase.getCollection("user");
            if (mongoCollection == null) {
                mongoDatabase.createCollection("user");
                mongoCollection = mongoDatabase.getCollection("user");
            }
            /* Insert document */
            mongoCollection.insertOne(new Document("user", "Alice").append("sex", "F"));
            List<Document> documents = new ArrayList<Document>();
            documents.add(new Document("user", "Bob").append("sex","M"));
            documents.add(new Document("user", "Chris").append("sex","F"));
            mongoCollection.insertMany(documents);
            /* Find documents */
            FindIterable<Document> findIterable = mongoCollection.find();
            MongoCursor<Document> mongoCursor = findIterable.iterator();
            while (mongoCursor.hasNext()) {
                System.out.println(mongoCursor.next());
            }
            mongoClient.close();
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }
    }
}

4. API接口说明

具体API说明参考链接手册

http://mongodb.github.io/mongo-java-driver/3.0/driver/getting-started/quick-tour/