MySQL プールされたカスタム インスタンスの分析

package com.funtester.db.mysql;
import com.funtester.base.interfaces.IMySqlBasic;
import com.funtester.config.SqlConstant;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
/**
 * mysql操作的基础类
 * <p>用于存储数据，多用于爬虫</p>
 */
public class FunMySql extends SqlBase implements IMySqlBasic {
    /**
     *  {@link SqlConstant#FUN_SQL_URL}会替换IP到URL
     */
    String url;
    /**
     * 库
     */
    String database;
    /**
     * 用户
     */
    String user;
    /**
     * 密码
     */
    String password;
    Connection connection;
    Statement statement;
    /**
     * 私有构造方法
     *
     * @param url      连接地址,包括端口
     * @param database 库
     * @param user     用户名
     * @param password 密码
     */
    public FunMySql(String url, String database, String user, String password) {
        this.url = url;
        this.database = database;
        this.user = user;
        this.password = password;
        getConnection(database);
    }
    /**
     * 初始化连接
     */
    @Override
    public void getConnection() {
        getConnection(EMPTY);
    }
    /**
     * 执行sql语句，非query语句，并不关闭连接
     *
     * @param sql
     */
    @Override
    public void executeUpdateSql(String sql) {
        SqlBase.executeUpdateSql(connection, statement, sql);
    }
    /**
     * 查询功能
     *
     * @param sql
     * @return
     */
    @Override
    public ResultSet executeQuerySql(String sql) {
        return SqlBase.executeQuerySql(connection, statement, sql);
    }
    /**
     * 关闭query连接
     */
    @Override
    public void over() {
        SqlBase.close(connection, statement);
    }
    @Override
    public void getConnection(String database) {
        if (connection == null)
            connection = SqlBase.getConnection(SqlConstant.FUN_SQL_URL.replace("ip", url).replace("database", database), user, password);
        if (statement == null) statement = SqlBase.getStatement(connection);
    }
}

    /**
     * 池化工厂类
     */
    private class FunTester extends BasePooledObjectFactory<FunMySql> {
        @Override
        FunMySql create() throws Exception {
            return new FunMySql(url, database, user, password)
        }
        @Override
        PooledObject<FunMySql> wrap(FunMySql obj) {
            return new DefaultPooledObject<FunMySql>(obj)
        }
        @Override
        void destroyObject(PooledObject<FunMySql> p) throws Exception {
            p.getObject().over()
            super.destroyObject(p)
        }
    }

/**
 * 自定义MySQL连接池对象
 */
class MysqlPool extends PoolConstant {
    private static final Logger logger = LogManager.getLogger(MysqlPool.class);
    /**
     * {@link com.funtester.config.SqlConstant#FUN_SQL_URL}会替换IP到URL*/
    String url;
    /**
     * 库
     **/
    String database;
    /**
     * 用户
     **/
    String user;
    /**
     * 密码
     **/
    String password;
    private GenericObjectPool<FunMySql> pool
    MysqlPool(String url, String database, String user, String password) {
        this.url = url
        this.database = database
        this.user = user
        this.password = password
        init()
    }
    /**
     * 初始化连接池
     * @return
     */
    def init() {
        GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig();
        poolConfig.setMaxTotal(MAX);
        poolConfig.setMinIdle(MIN_IDLE);
        poolConfig.setMaxIdle(MAX_IDLE);
        poolConfig.setMaxWaitMillis(MAX_WAIT_TIME);
        poolConfig.setMinEvictableIdleTimeMillis(MAX_IDLE_TIME);
        pool = new GenericObjectPool<FunMySql>(new FunTester(), poolConfig);
    }
}