写一段java监控sybase数据表变更的代码
时间: 2023-05-31 20:06:53 浏览: 54
下面是一个简单的Java代码示例,用于监控Sybase数据库表的变更。该代码使用JDBC连接到数据库,并使用JDBC的ResultSetMetaData类获取表的元数据信息,包括表名、列名、列类型等。然后,它使用Java的Timer类实现定时任务,定期检查表的元数据是否有变化。如果有变化,则输出变化信息。
```
import java.sql.*;
import java.util.Timer;
import java.util.TimerTask;
public class SybaseTableMonitor {
private static final String DRIVER_CLASS = "com.sybase.jdbc4.jdbc.SybDriver";
private static final String DB_URL = "jdbc:sybase:Tds:host:port/database";
private static final String DB_USER = "username";
private static final String DB_PASS = "password";
private String tableName;
private String[] columnNames;
private int[] columnTypes;
public SybaseTableMonitor(String tableName) {
this.tableName = tableName;
updateTableMetadata();
}
private void updateTableMetadata() {
try (Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM " + tableName + " WHERE 1=0")) {
ResultSetMetaData metadata = rs.getMetaData();
int columnCount = metadata.getColumnCount();
columnNames = new String[columnCount];
columnTypes = new int[columnCount];
for (int i = 1; i <= columnCount; i++) {
columnNames[i - 1] = metadata.getColumnName(i);
columnTypes[i - 1] = metadata.getColumnType(i);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public void startMonitoring(long intervalMs) {
Timer timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
checkTableMetadata();
}
}, 0, intervalMs);
}
private void checkTableMetadata() {
try (Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM " + tableName + " WHERE 1=0")) {
ResultSetMetaData metadata = rs.getMetaData();
int columnCount = metadata.getColumnCount();
if (columnCount != columnNames.length) {
System.out.println("Table structure has changed!");
updateTableMetadata();
return;
}
for (int i = 1; i <= columnCount; i++) {
if (!metadata.getColumnName(i).equals(columnNames[i - 1]) ||
metadata.getColumnType(i) != columnTypes[i - 1]) {
System.out.println("Table structure has changed!");
updateTableMetadata();
return;
}
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SybaseTableMonitor monitor = new SybaseTableMonitor("mytable");
monitor.startMonitoring(10000); // check every 10 seconds
}
}
```
请注意,在实际应用中,您可能需要更复杂的逻辑来处理表结构的变化,例如重新创建表或更新应用程序代码。此示例仅用于演示如何监视表结构的变化。