自己写了个PostgreSQL工具类

package com.demo.tools;

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

public class PostgreSQLUtils {
	
	private static final String DATABASE_NAME = "xsmt"; // 数据库名称
	private static final String USER_NAME = "postgres"; // 用户名
	private static final String PASS_WORD = "root";     // 密码
	private static Connection c = null; 				// 连接对象
	private static Statement stmt = null;				// SQL语句执行
	
	
	/**
	 * 获取连接
	 * @return
	 */
	public static Connection getConnection() {
		try {
			Class.forName("org.postgresql.Driver");
		} catch (ClassNotFoundException e1) {
			e1.printStackTrace();
		}
		try {
			c = DriverManager
					.getConnection("jdbc:postgresql://localhost:5432/"+DATABASE_NAME,USER_NAME,PASS_WORD);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return c;
	}
	
	public static void closeConnection() {
		  try {
				stmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	         try {
				c.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
	}
	
	
	/**
	 * 创建表
	 * @param sql 传入创建表的sql语句
	 * @return
	 */
	public static boolean createTable(String sql) {
		//Connection connection = PostgreSQLUtils.getConnection();
		//  String sql = "CREATE TABLE company " +
        //        "(ID INT PRIMARY KEY     NOT NULL," +
        //        " NAME           TEXT    NOT NULL, " +
        //        " AGE            INT     NOT NULL, " +
        //        " ADDRESS        CHAR(50), " +
        //        " SALARY         REAL)";
		PostgreSQLUtils.createTable(sql);
		System.out.println("创建成功");
		boolean flag = false;
		 try {
			stmt = c.createStatement();
			flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
			flag = false;
		}
         try {
			stmt.executeUpdate(sql);
		} catch (SQLException e) {
			e.printStackTrace();
			flag = false;
		}
        closeConnection();
		return flag;
         
	}
	

	/**
	 * 保存信息
	 * @param sql
	 * @return
	 */
	public static boolean save(String sql) {
//		Connection connection = PostgreSQLUtils.getConnection();
//		String sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)" + 
//				"VALUES (1, 'Paul', 32, 'California', 20000.00 );";
//		PostgreSQLUtils.save(sql);
		boolean flag = false;
		 try {
			stmt = c.createStatement();
			stmt.executeUpdate(sql);
			flag = true;
		} catch (SQLException e1) {
			e1.printStackTrace();
			flag = false;
		}
		 closeConnection();
		return flag;
	}
	
	
	/**
	 * 删除操作
	 * @param sql
	 * @return
	 */
	public static boolean delete(String sql) {
//		Connection connection = PostgreSQLUtils.getConnection();
//		String sql = "DELETE from COMPANY where ID=2;";
//		PostgreSQLUtils.delete(sql);
		boolean flag = false;
		 try {
			stmt = c.createStatement();
			stmt.executeUpdate(sql);
			flag = true;
		} catch (SQLException e1) {
			e1.printStackTrace();
			flag = false;
		}
		 closeConnection();
		return flag;
	}
	
	
	
	/**
	 * 更新操作
	 * @param sql
	 * @return
	 */
	public static boolean update(String sql) {
		//Connection connection = PostgreSQLUtils.getConnection();
		//String sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1;";
		//PostgreSQLUtils.update(sql);
		boolean flag = false;
		 try {
			stmt = c.createStatement();
			stmt.executeUpdate(sql);
			flag = true;
		} catch (SQLException e1) {
			e1.printStackTrace();
			flag = false;
		}
		 closeConnection();
		return flag;
	}
	
	
	
	
	
// 	<!-- https://mvnrepository.com/artifact/org.lucee/postgresql -->
//	<dependency>
//	    <groupId>org.lucee</groupId>
//	    <artifactId>postgresql</artifactId>
//	    <version>8.3-606.jdbc4</version>
//	</dependency>
	
}