Java JDBC操作异常处理策略示例

原创分手后的思念是犯贱 2024-10-11 12:48 64阅读 0赞

在Java中，JDBC（Java Database Connectivity）是与数据库交互的API。在操作过程中可能会遇到各种异常，下面是一个基本的异常处理策略示例：

```java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class JDBCExample {

private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/testdb";
    private static final String USER = "username";
    private static final String PASSWORD = "password";

public static void main(String[] args) {
        Connection connection = null;
        
        try {
            // 注册JDBC驱动
            Class.forName("com.mysql.jdbc.Driver");

// 获取数据库连接
            connection = DriverManager.getConnection(DATABASE_URL, USER, PASSWORD));

// 如果成功，执行一条SQL语句
            if (connection != null) {
                System.out.println("Database connection established.");
                // 假设你要执行一个查询
                String query = "SELECT * FROM users";
                PreparedStatement statement = connection.prepareStatement(query);
                
                try (ResultSet resultSet = statement.executeQuery()) {
                    while (resultSet.next()) {
                        System.out.println(resultSet.getString("username") + " - " + resultSet.getInt("age"));
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
                System.out.println("An error occurred while connecting to the database.");
            } finally {
                // 关闭数据库连接
                if (connection != null) {
                    connection.close();
                }

System.out.println("Database connection closed.");
            }
        } catch (ClassNotFoundException | SQLException e) {
            System.out.println("An error occurred: " + e.getMessage());
        }

System.exit(0);
    }
}
```

这个示例首先处理`ClassNotFoundException`，这是在注册JDBC驱动时可能遇到的。然后是`SQLException`，这是连接数据库或执行SQL操作时可能出现的问题。

最后无论是否成功，都会关闭数据库连接。