Java ??? ?? ???? ??? ???? ???? ??? ??????

???? ??? ??? ?? ???? ??? ??? ??? ? ?? ?? ??? ?????. Java ??? ???? ??? ???? ???? ?? ??? ?????. ? ????? ? ?? ???? ??? ??? ??? ???? ?? ??? ???? Java?? ??? ???? ???? ??? ?????.

1. ??? ??????

??? ??????? ??? ???? ?? ???? ?? ? ?????. Java??? JDBC(Java Database Connectivity)? ???? ??? ??????? ???? ??? ? ????. ??? JDBC? ???? MySQL ??????? ???? ?? ??? ???? ??? ???? ??? ????.

import java.sql.*;

public class JDBCDemo {
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

        try {
            // 1. 加載數(shù)據(jù)庫驅(qū)動
            Class.forName("com.mysql.jdbc.Driver");

            // 2. 建立數(shù)據(jù)庫連接
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");

            // 3. 創(chuàng)建Statement對象
            stmt = conn.createStatement();

            // 4. 執(zhí)行SQL語句
            rs = stmt.executeQuery("SELECT * FROM users");

            // 5. 處理查詢結(jié)果
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String email = rs.getString("email");
                System.out.println("ID: " + id + ", Name: " + name + ", Email: " + email);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 6. 關(guān)閉數(shù)據(jù)庫連接
            try {
                if (rs != null) rs.close();
                if (stmt != null) stmt.close();
                if (conn != null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

? ?? ???? ?? ?????? ????? ????, ?????? ??? ????, SQL ?? ???? ????? ?????. ?? ??. ????? ???? ???? ?? ?????? ??? ????.

2. ???? ??????

??? ?????? ??? ???? ??????(NoSQL)? ??? ???? ?? ?? ?? ??? ?????. Java??? MongoDB, Redis ?? ?? ?? ???? NoSQL ??????? ??? ? ????. ??? ??? ???? ?? MongoDB? ???? ????.

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

public class MongoDBDemo {
    public static void main(String[] args) {
        MongoClient mongoClient = null;

        try {
            // 1. 建立MongoDB連接
            String connectionString = "mongodb://localhost:27017";
            MongoClientURI uri = new MongoClientURI(connectionString);
            mongoClient = new MongoClient(uri);

            // 2. 獲取數(shù)據(jù)庫
            MongoDatabase database = mongoClient.getDatabase("test");

            // 3. 獲取集合
            MongoCollection<Document> collection = database.getCollection("users");

            // 4. 插入記錄
            Document user = new Document("name", "John Doe")
                    .append("email", "john.doe@example.com");
            collection.insertOne(user);

            // 5. 查詢記錄
            Document query = new Document("name", "John Doe");
            Document result = collection.find(query).first();
            if (result != null) {
                String name = result.getString("name");
                String email = result.getString("email");
                System.out.println("Name: " + name + ", Email: " + email);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 6. 關(guān)閉MongoDB連接
            if (mongoClient != null) mongoClient.close();
        }
    }
}

?? ?? ???? ?? MongoDB ??? ???? ?????? ? ??? ??? ?????. ?? ?? ???? ???? ??? ?? ???? ?????. ????? MongoDB ??? ????.

??

? ????? ??? ?????? ? ???? ??????? ???? Java ??? ?? ???? ??? ???? ???? ???? ??? ?????. JDBC ?? ?? ?????? ???? ?????? ???? Java? ??? ??????? ???? ??? ? ????. ???? ??????? ?? NoSQL ??????? ??? Java ????? ?????? ???? ??? ??? ??? ? ????. ? ??? Java ??? ???? ??? ???? ???? ? ??? ??? ????.

? ??? Java ??? ?? ???? ??? ???? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!