原始jdbc连接，判断表是否存在？填入sql语句查询计数

需求，日志表命名格式为xxx+时间，判断前一天文件是否自动生成。

工具类：获取后缀时间详见日期时间工具类

代码：获取数据库连接，关闭连接，判断表是否存在

package utils;

import java.sql.*;
import java.util.Properties;

public class TableExistsUtils {
    private static Connection connection = null;

    /**
     * 获取数据库连接
     *
     * @return
     */
    public static Connection getConnection() {
        PreparedStatement pre = null;

        try {
            /**
             *  1.获取Driver实现类对象，使用反射
             */
            Class clazz = Class.forName("com.mysql.jdbc.Driver");
            Driver driver = (Driver) clazz.newInstance();
            /**
             * 2.提供要连接的数据库
             */
            String url = "jdbc:mysql://localhost:3306/ssm_mimi";
            /**
             * 3.提供连接需要的用户名和密码
             */
            Properties info = new Properties();
            info.setProperty("user", "root");
            info.setProperty("password", "123456");

            /**
             * 4.获取连接
             */

            connection = driver.connect(url, info);

        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;

    }

    /**
     * 关闭连接
     *
     * @param conn
     */
    public static void close(Connection connection, PreparedStatement pst) {
        if (pst != null) {
            try {
                pst.close();
                pst = null;//如果没有关掉我们将它手动赋值为null
            } catch (SQLException e) {
                e.printStackTrace();
            }

        }
        if (connection != null) {
            try {
                connection.close();
                connection = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 判断数据库中是否存在表
     *
     * @param code 表名
     * @param conn 连接
     * @return
     */
    public static boolean isExists(String code, Connection conn) {
        boolean result = false;
        try {
            DatabaseMetaData meta = conn.getMetaData();
            ResultSet set = meta.getTables(null, null, code, null);
            //判断数据库表是否存在
            if (set.next()) {
                result = true;
            } else {
                result = false;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;

    }

}

功能实现

import models.bean.TableExists;
import net.sf.oval.constraint.Past;
import play.jobs.Every;
import play.jobs.Job;
import utils.DateUtils;
import utils.TableExistsUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class TableExistsJob{
public void getTable(){
/**
         * 获取数据库连接
         */
        Connection connection = TableExistsUtils.getConnection();
        TableExists tableExists = new TableExists();
        /**
         * 得到前一天的表名
         */
        String yesterdayDateString = DateUtils.getYesterdayDateString();
        String tableName = "pvlogs_" + yesterdayDateString;
        /**
         * 创建对象赋值
         */
        tableExists.table_name = tableName;
        /**
         * 传入表名判断是否存在
         */
        boolean exists = TableExistsUtils.isExists(tableName, connection);
        if (exists) {
            String sql = "select count(*) from " + tableName;
            PreparedStatement past = null;
            try {
                past = connection.prepareStatement(sql);
                ResultSet resultSet = past.executeQuery();
                resultSet.next();
                int count = resultSet.getInt(1);
                tableExists.table_count = count;
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                TableExistsUtils.close(connection, past);
            }
        } else {
            tableExists.table_error = "数据表未及时更新！请尽快处理";
        }
        tableExists.save();
    }
}