uncle.config.DatabaseHelper Maven / Gradle / Ivy

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package uncle.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import uncle.utils.PropsUtil;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

/**
 * Created by jack on 2017/7/18.
 * 数据库操作助手类
 */
public class DatabaseHelper {
    private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseHelper.class);
    private static final String DRIVER;
    private static final String URL;
    private static final String USERNAME;
    private static final String PASSWORD;
    private static final ThreadLocal CONNECTION_HOLDER = new ThreadLocal();

    static {
        Properties conf = PropsUtil.loadProps("config.properties");
        DRIVER = conf.getProperty("jdbc.driver");
        URL = conf.getProperty("jdbc.url");
        USERNAME = conf.getProperty("jdbc.username");
        PASSWORD = conf.getProperty("jdbc.password");
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            LOGGER.error("can not load jdbc driver", e);
        }
    }


    /**
     * 获取数据库连接
     */
    public static Connection getConnection() {
        Connection conn = CONNECTION_HOLDER.get();//1
        if (conn == null) {
            try {
                conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
            } catch (SQLException e) {
                LOGGER.error("get connection failure", e);
            } finally {
                CONNECTION_HOLDER.set(conn);
            }
        }
        return conn;
    }

    /**
     * 关闭数据库连接
     */
    public static void closeConnection() {
        Connection conn = CONNECTION_HOLDER.get();//1
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                LOGGER.error("close connection failure", e);
                throw new RuntimeException(e);
            } finally {
                CONNECTION_HOLDER.remove();//3
            }
        }
    }

    /**
     * 开启事务
     */
    public static void beginTransaction() {
        Connection connection = getConnection();
        if (connection != null) {
            try {
                connection.setAutoCommit(false);
            } catch (SQLException e) {
                LOGGER.error("begin transaction failure", e);
                throw new RuntimeException(e);
            } finally {
                CONNECTION_HOLDER.set(connection);
            }
        }
    }

    /**
     * 提交事务
     */
    public static void commitTransaction() {
        Connection connection = getConnection();
        if (connection != null) {
            try {
                connection.commit();
                connection.close();
            } catch (SQLException e) {
                LOGGER.error("commit transaction failure", e);
                throw new RuntimeException(e);
            } finally {
                CONNECTION_HOLDER.remove();
            }

        }
    }

    /**
     * 回滚事务
     */
    public static void rollbackTransaction() {
        Connection connection = getConnection();
        if (connection != null) {
            try {
                connection.rollback();
                connection.close();
            } catch (SQLException e) {
                LOGGER.error("rollback transaction failure", e);
                throw new RuntimeException(e);
            } finally {
                CONNECTION_HOLDER.remove();
            }

        }
    }

}