JDBC MySQL连接

环境InterlliJ2016.3  MySQL5.7.12

gradle依赖库：

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.11'

    compile 'org.slf4j:slf4j-log4j12:1.7.21'

    compile 'mysql:mysql-connector-java:5.1.39'
}

DBService.java

package com.mind.core.db.impl;  
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

/**
 * 数据库服务
 * Created by Lovell on 16/6/18.
 */
public class DBService {
    private static Logger logger = LoggerFactory.getLogger(DBService.class);

    private static final String DB_CONFIG_FILE = "/db.properties";

    // 数据库服务器addr
    private String db_addr = null;

    // 数据库名称
    private String db_name = null;

    // 数据库连接数
    private short db_max_conn;

    // 数据库登录用户名
    private String db_username = null;

    // 数据库登录密码
    private String db_password = null;

    // 数据库连接
    private Connection connection;

    private static DBService dBService;
    public static DBService getInstance(){
        if (dBService == null) {
            dBService = new DBService();
        }
        return dBService;
    }

    public void start() throws IOException {
        Properties properties = new Properties();
        InputStream in = DBService.class.getClass().getResourceAsStream(DB_CONFIG_FILE);
        properties.load(in);
        db_username = String.valueOf(properties.getProperty("db_username"));
        db_password = String.valueOf(properties.getProperty("db_password"));
        String addr = String.valueOf(properties.getProperty("db_addr"));
        String db_name = String.valueOf(properties.getProperty("db_name"));
        if (addr == null || addr.length() == 0) {
            logger.error("配置的数据库ip地址错误!");
            System.exit(0);
        }

        String driver = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://"+ addr +"/" + db_name + "?characterEncoding=utf8&useSSL=false";

        try {

            // 加载驱动程序
            Class.forName(driver);

            // 连接数据库
            connection = DriverManager.getConnection(url, db_username, db_password);

            if (!connection.isClosed())
                System.out.println("Succeeded connecting to the Database!");

            } catch(ClassNotFoundException e) {
                System.out.println("Sorry, can't find the Driver!");
                e.printStackTrace();
            } catch(SQLException e) {
                e.printStackTrace();
            } catch(Exception e) {
                e.printStackTrace();
            }
    }

    public Connection getConnection() {
        return connection;
    }

    public boolean stop() throws SQLException {
        if (connection != null) {
            connection.close();
        }
        return true;
    }
}

MySQLTest.java

package com.mind.core.db.impl;

import java.sql.ResultSet;
import java.sql.Statement;

/**
 * Created by Lovell on 16/6/21.
 */
public class MySQLTest {
    public static void main(String[] args) throws Exception {
        DBService.getInstance().start();

        // statement用来执行SQL语句
        Statement statement = DBService.getInstance().getConnection().createStatement();

        // 要执行的SQL语句id和content是表review中的项。
        String sql = "select * from login where name='Lovell' and password='123456'";

        // 得到结果
        ResultSet rs = statement.executeQuery(sql);

        if(rs.next()){
            System.out.println("Logon");

        }else{
            System.out.println("Login Faild");
        }
        rs.close();

    }
}