Flex BlazeDS Java JDBC MySql 快速配置

从下往上:

1. Java – JDBC – MySql

1. 装好MySql, 启动服务.

2. 将mysql-connector-java-5.1.7-bin.jar 拖入WEB-INF/lib下.

搞定.

2. Java端BlazeDS配置

1. Java端:

将BlazeDS压缩包内的WEB-INF里面的东西拷贝工程内的WEB-INF下的相应位置中.[ Flex目录下有四个xml配置文件, lib下是需要使用的jar] 包括web.xm

2. 配置services-config.xml中channels标签中的内容:

  

        
            
        

        
            

                false
            
        

        
            

true
4
            
        

其中, http://localhost:8080/DepartmentManagement/ 是该Web工程的地址 [可在web-content下建立一空index.html, 运行后查看地址便可]

3. 编写Java类, 并配置remoting-config.xml文件的<service>标签下, 增加服务, 如下:

     

         com.insprise.guoliang.DepartmentManagement
       

3. Flex端建立工程

1. 建立 Flex与Java通信载体RemoteObject

为方便在整个工程中使用, 可建立一个Singleton – 关于AS中的Singleton可见: http://liguoliang.com/2008/10/128/

在该类中建立RemoteObject.

首先需要确定RemoteObject的destination, 在本例中 为”DepartmentManagement”; – 在remoting-config.xml中已配置.

其次需要确定ro的channel – 本例中为:”http://localhost:8080/DepartmentManagement/messagebroker/amf＂； － 在services-config.xml中已配置

代码:

	public static const DEFAULT_DEST:String = "DepartmentManagement";
	public static const DEFAULT_CHANNEL_URL:String = "http://localhost:8080/DepartmentManagement/messagebroker/amf";
	private static var _ro:RemoteObject;

	/**
	 * Constractor - Singleton
	 */
	 public function AppContext():void {
	 	throw new Error("AppContext is Singleton!");
	 }

	/**
	 * Get RemoteObject
	 */
	public static function getRemoteObject():RemoteObject {
		if(_ro == null) {
			_ro = createRemoteObject(DEFAULT_DEST, DEFAULT_CHANNEL_URL);
		}
		return _ro;
	}

	/**
	 * Constructs a new remote object with new channel.
	 * @param roDestination Destination of the RemoteObject; should match a destination name in the services-config.xml file.
	 * @param channelURI the URI used to create the whole endpoint URI for this channel; this uri can be relative uri (to the folder containing the SWF).
	 * @param channelId the id of the channel, if set to null, a random Id will be assigned.
	 */
	protected static function createRemoteObject(roDestination:String, channelURI:String, channelId:String = null):RemoteObject {
		var channelSet:ChannelSet = new ChannelSet();
		var channel:AMFChannel = new AMFChannel(channelId == null ? "channel-" : channelId, channelURI);	//Create new Channel
		channelSet.addChannel(channel);	

		var ro:RemoteObject = new RemoteObject(roDestination);
		ro.channelSet = channelSet;

		return ro;
	}

4 配置完成,.

在Java端建立相关的Class,

启动服务器.

在Flex端通过 Appcontext.getRemoteObject.getOperation(“方法名称”)来调用服务器端方法.

具体实例:

Java端的Class – 通过JDBC 读取 MySql中数据:

	/**
	 * Load all Department and return an ArrayList
	 * @return
	 */
	public ArrayList loadDepartments() {
		ArrayList departmentsAL = new ArrayList();
		log.info("Loading Departments...");
		try {
			//Get Connection
			Connection conn = JdbcUtilities.getConnection();
			//Create statement
			String sql = " SELECT * FROM Department d ORDER BY d.Department_ID";
			PreparedStatement ps = conn.prepareStatement(sql);

			ResultSet res = ps.executeQuery();
			log.debug("Exectuing: " + sql);
			while (res.next()) {
				int id = res.getInt("Department_ID");
				String name = res.getString("name");

				Department dp = new Department();
				dp.setId(id);
				dp.setName(name);
				departmentsAL.add(dp);
				log.debug("从数据库获得部门:  " + dp);
			}
			JdbcUtilities.closeConn(res, ps, conn);
			log.info("加载部门信息结束, 共加载部门: " + departmentsAL.size());
		} catch (Exception e) {
			log.error("SQL Error", e);
			throw new Error(e);
		}
		return departmentsAL;

	}

Flex端的代码:

		/**
	 * Load the Department's Employee
	 */

	private var op:AbstractOperation;
	public function loadEmployees():void {
		op = AppContext.getRemoteObject().getOperation("loadEmployees");	//获得Operation
		 op.arguments = [id];	//设定参数
		 var at:AsyncToken = op.send();	//Send
		 at.addResponder(this);	//为本实例增加responder

      }

Flex端responder剩余代码见:http://liguoliang.com/2009/02/777/

运行Flex工程, Flex取得RemoteObject, 然后通过channel建立到destination的连接,由Java读取数据库中信息, 并返回给Flex.

Flex端调用Java服务的过程

1. get Operation

2. set arguments

3. AddResponder, Send();

如下:

	private var op:AbstractOperation;
	public function loadEmployees():void {
		op = AppContext.getRemoteObject().getOperation("loadEmployees");	//获得Operation
		 op.arguments = [id];	//设定参数
		 op.send();
		 var at:AsyncToken = op.send();	//Send
		 at.addResponder(this);	//为本实例增加responder
      }
//使用当前类响应, 则应实现IResponder接口, 要实现两个方法, 如下:
//---------------------Responder-------------------------------
	public function result(responderResult:Object):void {
		var resultEvent:ResultEvent = responderResult as ResultEvent;//转换
		var ac:ArrayCollection = resultEvent.result as ArrayCollection;//获得Result
		log.debug("已读取到 " + this + "的职员列表, 职员数目为: " + ac.length);
	}

	public function fault(data:Object):void {
		throw new Error("远程操作失败");
	}

原先的错误方法:

	private var op:AbstractOperation;
	public function loadEmployees():void {
		op = AppContext.getRemoteObject().getOperation("loadEmployees");	//获得Operation
		 op.arguments = [id];	//设定参数
		 op.addEventListener(ResultEvent.RESULT, onSqlResult,false, 0, true);
		 op.send();
		// var at:AsyncToken = op.send();	//Send
		 //at.addResponder(this);	//为本实例增加responder
      }

	private function onSqlResult(e:ResultEvent):void {
		var ac:ArrayCollection = e.result as ArrayCollection;
		for each(var emp:Employee in ac) {
			emp.department = this;
			employeeAC.addItem(emp);
		}
		log.debug("已读取到 " + this + "的职员列表, 职员数目为: " + ac.length);
		op.removeEventListener(ResultEvent.RESULT, onSqlResult);//更错误的方法是没有remove Listener
	}

这样导致该方法被呼叫时, op都会被监听, 成功后取消监听, 如果不取消监听, 则会出现如下输出信息:
第一次调用:
[DEBUG] Department 已读取到 Dep1的职员列表, 职员数目为: 2

第二次调用:
[DEBUG] Department 已读取到 Dep1的职员列表, 职员数目为: 2
[DEBUG] Department 已读取到 Dep2的职员列表, 职员数目为: 2

第三次调用:
[DEBUG] Department 已读取到 Dep1的职员列表, 职员数目为: 0
[DEBUG] Department 已读取到 Dep2的职员列表, 职员数目为: 0
[DEBUG] Department 已读取到 Department3的职员列表, 职员数目为: 0

在此情况下, op可视为一类操作, 这样在使用op[他会有很多个实例, 会有很多个对应的监听函数]监听之后, 每个实例的Result的返回都会引发所有实例的Listener运行. 因此会出现上面的状况.

BlazeDS配置实例

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作者:http://liguoliang.com 欢迎访问:Adobe上海用户组: http://riashanghai.com ]

public class HelloWorld {
public String sayHello(String name) {
return "hello, " + name;
}
}

		HelloWorld

重新启动Tomcat;

<?xml version="1.0" encoding="utf-8"?>

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