如何在Java中使用数据库连接？实例详解

原创女爷i 2024-12-06 17:36 7阅读 0赞

在Java中，我们可以使用多种方式来建立数据库连接。这里以两个常用的数据库——MySQL和Oracle为例进行详细介绍。

1. 使用JDBC（Java Database Connectivity）：

这是最传统的方式，Java标准库提供了一套API来操作数据库。

- MySQL:
```java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class MySQLExample {
    private static final String URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String USER = "username";
    private static final String PASS = "password";

public static void main(String[] args) {
        try (Connection connection = DriverManager.getConnection(URL, USER, PASS)) {
            System.out.println("Database connection established.");
            // Perform operations here
        } catch (SQLException e) {
            System.err.println("Error connecting to database: " + e.getMessage());
        }
    }
}
```
- Oracle:
```java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class OracleExample {
    private static final String URL = "jdbc:oracle:thin:@localhost:1521:orcl";
    private static final String USER = "username";
    private static final String PASS = "password";

public static void main(String[] args) {
        try (Connection connection = DriverManager.getConnection(URL, USER, PASS))) {
            System.out.println("Database connection established.");
            // Perform operations here
        } catch (SQLException e) {
            System.err.println("Error connecting to database: " + e.getMessage());
        }
    }
}
```
2. 使用ORM（Object-Relational Mapping）工具：

现代Java开发中，通常会使用如Hibernate、MyBatis等ORM框架来操作数据库。

以Hibernate为例：

```java
import org.hibernate.Session;
import org.hibernate.Transaction;

public class HibernateExample {
    private Session session;

// ... getters and setters ...

public void connectToDatabase() throws SQLException {
        //... establish connection using Hibernate ...
        session = HibernateUtil.getSessionFactory().openSession();
    }

// ... perform operations with session ...
}
```
请根据你的实际数据库类型和使用工具选择合适的代码。