scala实现代理模式

package com.linewell.modeldesgin.proxy

import com.linewell.modeldesgin.dao.AccessDAO

import scala.collection.mutable.ArrayBuffer

/**
* 代理模式
* Created by ctao on 2015/8/29.
*/
/**
* 抽象主题类：查询特质
*/
trait Searcher {
    def doSearch(id: String, pass: String, keyword: String): String
}

/**
* 身份验证业务单例对象
*/
object AccessValidator {
    /**
     * 验证方法
     * @param id 查询的id
     * @param pass 用户名
     * @return 用户是否合法
     */
    def validate(id: String, pass: String): Boolean = {
        println(s"数据库验证$id 是否为合法用户")
        val params = new ArrayBuffer[Any]()
        params += id
        val result = AccessDAO.checkUser(params)

        /**
         * 判断result.head获取第一个元素的name和result.head获取第一个元素的pass和传入的id和pass是否一致
         * 一致返回true，否则返回false
         */
        if (result.head.getOrElse("name", "null") == id && result.head.getOrElse("pass", "null").toString == pass) {
            println("登录成功")
            true
        } else {
            println("登录失败")
            false
        }
    }

}

/**
* 日志记录类
*/
object Logger {
    /**
     * 记录日志
     * @param id 登录id
     */
    def log(id: String): Unit = {
        val params = new ArrayBuffer[Any]()
        params += id
        val row = AccessDAO.insertLog(params)
        if (row > 0) {
            println(s"记录$id 到数据库")

        } else {
            println("出现异常")
        }

    }
}

/**
* 真实主题类：具体查询类
*/
object RealSearcher extends Searcher {
    /**
     * 复写查询方法
     * @param id 用户id
     * @param pass pass
     * @param keyword 关键字
     * @return 查询内容
     */
    override def doSearch(id: String, pass: String, keyword: String): String = {
        println(s"用户：$id 使用关键字$keyword 查询商务信息！")
        "具体内容"
    }
}

/**
* 代理主题类：代理查询类
*/
object ProxySearcher extends Searcher {
    /**
     * 真实查询对象
     */
    private val realSearcher = RealSearcher
    /**
     * 身份验证对象
     */
    private val accessValidator = AccessValidator
    /**
     * 日志对象
     */
    private val logger = Logger

    /**
     * 复写查询
     * @param id 用户id
     * @param pass 密码
     * @param keyword 关键字
     * @return 查询结果
     */
    override def doSearch(id: String, pass: String, keyword: String): String = {
        /**
         * 判断是否登录成功，如果登录成功则记录到数据库中，并执行真实查询类的查询方法
         */
        if (validate(id, pass)) {
            log(id)
            realSearcher.doSearch(id, pass, keyword)
        } else {
            null
        }
    }

    /**
     * 日志方法，使用日志对象的日志方法
     * @param id 用户id
     */
    def log(id: String): Unit = logger.log(id)

    /**
     * 身份验证类
     * @param id 用户id
     * @param pass 密码
     * @return 是否验证成功
     */
    def validate(id: String, pass: String): Boolean = accessValidator.validate(id, pass)
}



package com.linewell.modeldesgin.dao

import com.linewell.modeldesgin.DBUtil.MySQLDBConn

import scala.collection.mutable.ArrayBuffer

/**
* 代理帐号操作数据库对象
* Created by ctao on 2015/8/29.
*/
object AccessDAO {
    /**
     * 查询sql
     */
    private val sqlSelect = "select name,pass from user where name = ?"

    /**
     * 查询
     * @param params 参数列表
     * @return ArrayBuffer
     */
    def checkUser(params: ArrayBuffer[Any]) = MySQLDBConn.Result(sqlSelect, params)

    /**
     * 插入日志列表sql
     */
    private val sqlInsert = "insert into log(userid) values(?)"

    /**
     * 插入操作
     * @param params 参数
     * @return 受影响行数
     */
    def insertLog(params: ArrayBuffer[Any]) = MySQLDBConn.updateRow(sqlInsert, params)


}



package com.linewell.modeldesgin.DBUtil

import java.sql._

import scala.collection.mutable
import scala.collection.mutable.ArrayBuffer

/**
* Mysql数据库连接
* Created by ctao on 2015/8/29.
*/
object MySQLDBConn {
    try {
        /**
         * 加载驱动
         */
        classOf[com.mysql.jdbc.Driver]
    } catch {
        case e: ClassNotFoundException => e.printStackTrace()
    }

    /**
     * 获取数据库连接
     * @return 数据库连接
     */
    def connection(): Connection = DriverManager.getConnection(DBUtil.url, DBUtil.username, DBUtil.pass)

    /**
     * 返回查询的结果保存成ArrayBuffer
     * @param sql 执行sql语句
     * @param params 参数
     * @return ArrayBuffer
     */
    def Result(sql: String, params: ArrayBuffer[Any]): ArrayBuffer[mutable.HashMap[Any, Any]] = {
        var arrayBuffer = new ArrayBuffer[mutable.HashMap[Any, Any]]()
        var conn: Connection = null
        var prepare: PreparedStatement = null
        var rs: ResultSet = null
        try {
            conn = connection()
            prepare = conn.prepareStatement(sql)
            var i = 0
            if (params != null) {
                if (params.nonEmpty) {
                    for (s <- params) {
                        prepare.setObject(i + 1, s)
                        i += 1
                    }
                }
            }

            rs = prepare.executeQuery()
            while (rs.next()) {
                val md = rs.getMetaData
                val column = md.getColumnCount

                var rowData = new mutable.HashMap[Any, Any]()
                for (i <- 1 to column) {
                    rowData.put(md.getColumnName(i), rs.getObject(i))
                }
                arrayBuffer += rowData
            }

        } catch {
            case sql: SQLException => sql.printStackTrace()
        } finally {
            closeAll(conn, prepare, rs)
        }
        arrayBuffer

    }

    /**
     * 更新受影响行数
     * @param sql sql语句
     * @param params 参数
     * @return 受影响行数
     */
    def updateRow(sql: String, params: ArrayBuffer[Any]): Int = {
        var conn: Connection = null
        var prepare: PreparedStatement = null
        try {
            conn = connection()
            prepare = conn.prepareStatement(sql)
            var i = 0
            if (params != null) {
                if (params.nonEmpty) {
                    for (s <- params) {
                        prepare.setObject(i + 1, s)
                        i += 1
                    }
                }
            }
            return prepare.executeUpdate()
        } catch {
            case sql: SQLException => sql.printStackTrace()
        } finally {
            closeAll(conn, prepare, null)
        }
        -1
    }

    /**
     * 关闭数据库连接
     * @param conn 数据库连接
     */
    def closeConn(conn: Connection): Unit = {
        conn.close()
    }

    /**
     * 关闭resultSet
     * @param resultSet resultSet
     */
    def closeResultSet(resultSet: ResultSet): Unit = {
        resultSet.close()
    }

    /**
     * 关闭preparedStatement
     * @param preparedStatement preparedStatement
     */
    def closePreparedStatement(preparedStatement: PreparedStatement): Unit = {
        preparedStatement.close()
    }

    /**
     * 关闭全部
     * @param connection connection
     * @param preparedStatement preparedStatement
     * @param resultSet resultSet
     */
    def closeAll(connection: Connection, preparedStatement: PreparedStatement, resultSet: ResultSet): Unit = {
        if (connection != null) {
            closeConn(connection)
        }
        if (preparedStatement != null) {
            closePreparedStatement(preparedStatement)
        }
        if (resultSet != null) {
            closeResultSet(resultSet)
        }
    }


}

package com.linewell.modeldesgin.proxy

/**
* 测试客户端
* Created by ctao on 2015/8/29.
*/
object Client extends App {
    val searcher1: Searcher = ProxySearcher
    println(searcher1.doSearch("ctt", "12223", "hello"))
    val searcher2: Searcher = ProxySearcher
    println(searcher2.doSearch("ct", "12334", "helloworld"))

    print(searcher1.eq(searcher2))

}