Java连接MongoDB实现增删改查

一、安装MongoDB驱动
在maven项目pom.xml文件中添加以下代码注入依赖：

<dependency>
	<groupId>org.mongodb</groupId>
	<artifactId>mongodb-driver</artifactId>
	<version>3.12.7</version>
</dependency>

二、创建如下所示的test数据库和stu集合

三、创建javamongodb包和 MongoDBUtil客户端访问类

package javamongodb;

import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;

import java.util.logging.Level;
import java.util.logging.Logger;

public class MongoDBUtil {
    
    
    // 设置服务器地址和端口号
    public static String host = "localhost";
    public static int port = 27017;

    // 当类被加载时，静态代码块只执行一次，此处的作用是为了提高日志输出级别，减少日志输出
    static {
    
    
        Logger mongoLogger = Logger.getLogger("org.mongodb.driver");
        mongoLogger.setLevel(Level.SEVERE);
    }

    // 获取Mongo客户端
    public static MongoClient getMongoClient() {
    
    
        MongoClient mClient = null;
        try {
    
    
            mClient = new MongoClient(host, port);
            System.out.println("连接成功！");
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
        return mClient;
    }
    
    // 关闭mongo客户端
    public static void closeMongoClient(MongoClient mClient) {
    
    
        try {
    
    
            if (mClient != null) {
    
    
                mClient.close();
                System.out.println("释放资源！");
            }
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }
    
    // 获取数据库中的集合
    public static MongoCollection<Document> getCol(MongoClient mClient, String dbName, String colName) {
    
    
        MongoCollection<Document> col = null;
        try {
    
    
            MongoDatabase db = mClient.getDatabase(dbName);
            col = db.getCollection(colName);
        } catch (Exception e) {
    
    
            System.out.println("集合获取失败：" + e.getMessage());
        }
        return col;
    }
}

四、创建mongo工具类MongoDBTools

package javamongodb;

import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.Filters;
import org.bson.Document;
import org.bson.conversions.Bson;

import java.util.ArrayList;

public class MongoDBTools {
    
    
    public void insertOne(String name, String sex, int score) {
    
    
        MongoClient mClient = null;
        try {
    
    
            mClient = MongoDBUtil.getMongoClient();
            MongoCollection<Document> collection = MongoDBUtil.getCol(mClient, "test", "stu");
            Document doc = new Document("name", name).append("sex", sex).append("score", score);
            collection.insertOne(doc);
            System.out.println("文档添加成功！");
        } catch (Exception e) {
    
    
            System.out.println("文档添加失败：" + e.getMessage());
        } finally {
    
    
            if (mClient != null) {
    
    
                MongoDBUtil.closeMongoClient(mClient);
            }
        }
    }

    public void deleteByName(String name) {
    
    
        MongoClient mClient = null;
        try {
    
    
            mClient = MongoDBUtil.getMongoClient();
            MongoCollection<Document> collection = MongoDBUtil.getCol(mClient, "test", "stu");
            Bson filter = Filters.eq("name", name);
            collection.deleteMany(filter);
            System.out.println("文档删除成功！");
        } catch (Exception e) {
    
    
            System.out.println("文档删除失败：" + e.getMessage());
        } finally {
    
    
            if (mClient != null) {
    
    
                MongoDBUtil.closeMongoClient(mClient);
            }
        }
    }

    public void updateByName(String name, String updatedName, String sex, int score) {
    
    
        MongoClient mClient = null;
        try {
    
    
            mClient = MongoDBUtil.getMongoClient();
            MongoCollection<Document> collection = MongoDBUtil.getCol(mClient, "test", "stu");
            Bson filer = Filters.eq("name", name);
            Document doc = new Document("name", updatedName).append("sex", sex).append("score", score);
            collection.replaceOne(filer, doc);
            System.out.println("文档更新成功！");
        } catch (Exception e) {
    
    
            System.out.println("文档更新失败：" + e.getMessage());
        } finally {
    
    
            if (mClient != null) {
    
    
                MongoDBUtil.closeMongoClient(mClient);
            }
        }
    }

    public ArrayList<Document> findByName(String name) {
    
    
        MongoClient mClient = null;
        ArrayList<Document> arrLst = new ArrayList<>();
        try {
    
    
            mClient = MongoDBUtil.getMongoClient();
            MongoCollection<Document> collection = MongoDBUtil.getCol(mClient, "test", "stu");
            Bson filter = Filters.eq("name", name);
            FindIterable<Document> iterable = collection.find(filter);
            for (Document document : iterable) {
    
    
                arrLst.add(document);
            }
            System.out.println("文档查找成功！");
        } catch (Exception e) {
    
    
            System.out.println("文档查找失败：" + e.getMessage());
        } finally {
    
    
            if (mClient != null) {
    
    
                MongoDBUtil.closeMongoClient(mClient);
            }
        }
        return arrLst;
    }
}

五、创建测试类TestMongoDBTools
1、测试MongoDBTools类insertOne方法：


2、测试MongoDBTools类deleteByName方法


3、测试MongoDBTools类updateByName方法


4、测试MongoDBTools类findByName方法