Java如何检索数据库中的可用目录？
下面的示例向您展示如何在MySQL数据库中获取可用的目录名称。可以DatabaseMetaData通过调用getCatalogs()方法从对象获得可用的目录名称。此方法返回一个ResultSet对象。我们对其进行迭代，并通过调用getString()方法获得模式名称，并将其TABLE_CAT作为列名称传递。
package org.nhooo.example.jdbc;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class MetadataGetCatalog {
private static final String URL = "jdbc:mysql://localhost";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
public static void main(String[] args) {
try (Connection connection =
DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
//获取DatabaseMetaData
DatabaseMetaData metadata = connection.getMetaData();
//检索此数据库中可用的架构名称
ResultSet rs = metadata.getCatalogs();
while (rs.next()) {
String catalog = rs.getString("TABLE_CAT");
System.out.println("Catalog: " + catalog);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}这里是MySQL数据库中可用的目录名称列表：
Catalog: nhooo Catalog: mediadb Catalog: mysql Catalog: performance_schema Catalog: sys
Maven依赖
<!-- https://search.maven.org/remotecontent?filepath=mysql/mysql-connector-java/8.0.17/mysql-connector-java-8.0.17.jar -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.17</version>
</dependency>