上面代码中的getLastSyncTimeFromDb方法和saveLastSyncTimeToDb方法应该如何用java代码编写,
时间: 2024-03-09 14:46:15 浏览: 19
假设getLastSyncTimeFromDb方法返回一个字符串类型的时间戳,saveLastSyncTimeToDb方法接受一个字符串类型的时间戳作为参数,并将该时间戳保存到数据库中。
Java代码实现如下:
```java
import java.sql.*;
public class DatabaseHandler {
private Connection conn;
// 连接数据库
public void connect() throws SQLException {
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "username", "password");
}
// 从数据库中获取上次同步时间戳
public String getLastSyncTimeFromDb() throws SQLException {
String lastSyncTime = null;
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT last_sync_time FROM sync_table");
if (rs.next()) {
lastSyncTime = rs.getString("last_sync_time");
}
rs.close();
stmt.close();
return lastSyncTime;
}
// 将时间戳保存到数据库中
public void saveLastSyncTimeToDb(String lastSyncTime) throws SQLException {
PreparedStatement pstmt = conn.prepareStatement("UPDATE sync_table SET last_sync_time = ?");
pstmt.setString(1, lastSyncTime);
pstmt.executeUpdate();
pstmt.close();
}
// 关闭数据库连接
public void close() throws SQLException {
if (conn != null) {
conn.close();
}
}
}
```
使用示例:
```java
public static void main(String[] args) {
DatabaseHandler dbHandler = new DatabaseHandler();
try {
dbHandler.connect();
String lastSyncTime = dbHandler.getLastSyncTimeFromDb();
System.out.println("Last sync time: " + lastSyncTime);
// 进行同步操作
String newSyncTime = "2022-01-01 00:00:00";
dbHandler.saveLastSyncTimeToDb(newSyncTime);
System.out.println("Sync time updated to: " + newSyncTime);
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
dbHandler.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
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