java实现输出数据表的所有字段

近期在做sql语句优化，需要获取表的所有字段，遇到表字段多的时候，一个个字段拷贝太麻烦，于是做了简单的实现，这样搞着好多了。代码如下：

package net.test;

import java.sql.*;

public class TestSQL {
    static String url = "jdbc:postgresql://192.168.1.20:5432/db";
    static String usr = "postgres";
    static String psd = "123456";
 
    public static void main(String args[]) {
       Connection conn = null;
       try {
           Class.forName("org.postgresql.Driver");
           conn = DriverManager.getConnection(url, usr, psd);
           Statement st = conn.createStatement();
           ResultSet rs = st.executeQuery("SELECT attname FROM pg_class c,pg_attribute a " +
                   "WHERE c.relname  = 'tb_Student' " +
                   "AND c.oid = a.attrelid AND a.attnum>0;");
           while (rs.next()) {
              System.out.println(rs.getString(1));
           }
           rs.close();
           st.close();
           conn.close();
       } catch (Exception e) {
           e.printStackTrace();
       }
    }
    
}