scala实现设计模式之代理模式

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.daoimport com.linewell.modeldesgin.DBUtil.MySQLDBConnimport 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.DBUtilimport java.sql._import scala.collection.mutableimport 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))

}