scala实现jetty启动webservice调用restapi的简单框架

# 代码结构
-ui
	-restapi
		-GatewayRestful.scala
		-GatewayRestfulApi.scala
		-RestfulActiveServers.scala
		-RestfulJobToServer.scala
	-server
		-InitServer.scala

GatewayRestfulApi 继承了 HttpServlet类

RestfulActiveServers、RestfulJobToServer继承了GatewayRestfulApi

GatewayRestful收集所有定义好的HttpServlet

InitServer在启动server的时候直接从GatewayRestful中获取到所有定义的HttpServlet。

使用

代码在最下方。

我把main函数定义在InitServer当中，端口随意定义了一个8099。

启动InitServer后，发起一个http的通信。比如我在RestfulActiveServers中定义的路径是/rest/activeServers

那么在网页中输入:

localhost:8099/rest/activeServers

可以看到最简单的信息”activeServers”，这是我们自己定义的返回结果。你可以根据自己需要去处理得到这个返回结果。

代码

// GatewayRestful.scala
package ui.restapi

import scala.collection.mutable.ArrayBuffer

object GatewayRestful {
  val services = new ArrayBuffer[GatewayRestfulApi]

  services += new RestfulActiveServers
  services += new RestfulJobToServer

  def initRestServices(): Seq[GatewayRestfulApi] = {
    services.toSeq
  }
}

// GatewayRestfulApi.scala
package ui.restapi

import javax.servlet.http.{HttpServlet, HttpServletRequest, HttpServletResponse}

abstract class GatewayRestfulApi extends HttpServlet {

  val CharacterEncoding = "utf-8"

  def getPath(): String

  @inline
  private def initResp(resp: HttpServletResponse): Unit = {
    resp.setHeader("content-type", "application/json;charset=UTF-8")
  }

  protected def restfulGet(req: HttpServletRequest): String = {
    throw new UnsupportedOperationException
  }

  final override def doGet(req: HttpServletRequest, resp: HttpServletResponse): Unit = {
    initResp(resp)
    try {
      resp.getOutputStream.write(restfulGet(req).getBytes(CharacterEncoding))
    } catch {
      case e: UnsupportedOperationException => resp.sendError(400)
      case e: Throwable => resp.sendError(400, e.getStackTraceString)
    }
  }

  protected def restfulPost(req: HttpServletRequest): String = {
    throw new UnsupportedOperationException
  }

  final override def doPost(req: HttpServletRequest, resp: HttpServletResponse): Unit = {
    resp.setCharacterEncoding(CharacterEncoding)
    try {
      resp.getOutputStream.write(restfulPost(req).getBytes(CharacterEncoding))
    } catch {
      case e: UnsupportedOperationException => resp.sendError(400)
      case e: Throwable => resp.sendError(400, e.getStackTraceString)
    }
  }

  protected def restfulDelete(req: HttpServletRequest): String = {
    throw new UnsupportedOperationException
  }

  final override def doDelete(req: HttpServletRequest, resp: HttpServletResponse): Unit = {
    resp.setCharacterEncoding(CharacterEncoding)
    try {
      resp.getOutputStream.write(restfulDelete(req).getBytes(CharacterEncoding))
    } catch {
      case e: UnsupportedOperationException => resp.sendError(400)
      case e: Throwable => resp.sendError(400, e.getStackTraceString)
    }
  }

  protected def restfulPut(req: HttpServletRequest): String = {
    throw new UnsupportedOperationException
  }

  final override def doPut(req: HttpServletRequest, resp: HttpServletResponse): Unit = {
    resp.setCharacterEncoding(CharacterEncoding)
    try {
      resp.getOutputStream.write(restfulPut(req).getBytes(CharacterEncoding))
    } catch {
      case e: UnsupportedOperationException => resp.sendError(400)
      case e: Throwable => resp.sendError(400, e.getStackTraceString)
    }
  }
}

// RestfulActiveServers.scala
package ui.restapi

import javax.servlet.http.HttpServletRequest
import scala.collection.mutable.ArrayBuffer

class RestfulActiveServers extends GatewayRestfulApi {
  override def getPath(): String = "/rest/activeServers"

  override protected def restfulGet(req: HttpServletRequest): String = {

    val list = new ArrayBuffer[String]()
    "activeServers"

  }
}

// RestfulJobToServer.scala
package ui.restapi


import javax.servlet.http.HttpServletRequest

class RestfulJobToServer extends GatewayRestfulApi {
  override def getPath(): String = "/rest/jobToServer/*"

  override protected def restfulGet(req: HttpServletRequest): String = {
    val param = req.getPathInfo
    val jobName = if (param != null && param.size > 0) param.substring(1) else ""
    "jobToServer"
  }
}

// InitServer.scala
package tools.ui.server

import org.eclipse.jetty.server.{Server, SessionManager}
import org.eclipse.jetty.server.session.{HashSessionManager, SessionHandler}
import org.eclipse.jetty.servlet.{ServletContextHandler, ServletHolder}
import tools.ui.restapi.GatewayRestful

/**
  * Top level user interface for a Spark application.
  */
class InitServer(port: Int) {

  initialize()

  def initialize() {

    var server: Server = new Server(port)
    var contextHandler: ServletContextHandler = new ServletContextHandler()

    try {
      var sm: SessionManager = new HashSessionManager()

      contextHandler.setSessionHandler(new SessionHandler(sm))
      GatewayRestful.initRestServices().foreach{ api =>
        val holder = new ServletHolder(api)
        contextHandler.addServlet(holder, api.getPath())
      }

      server.setHandler(contextHandler)
      server.start
    }catch {
      case e: Exception =>
        e.printStackTrace()
        server.stop
    }

  }
}

object InitServer {
  def main(args: Array[String]): Unit ={
    new InitServer(8099)
  }
}

赏

谢谢你请我吃糖果

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