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))

}