Mule自带例子之flight-reservation

1 配置效果图

2 应用的配置文件

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

<mule xmlns:scripting="http://www.mulesoft.org/schema/mule/scripting" xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns:json="http://www.mulesoft.org/schema/mule/json"
    xmlns:ajax="http://www.mulesoft.org/schema/mule/ajax" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
    xmlns:spring="http://www.springframework.org/schema/beans" version="CE-3.4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/ajax http://www.mulesoft.org/schema/mule/ajax/current/mule-ajax.xsd
http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd
http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/scripting http://www.mulesoft.org/schema/mule/scripting/current/mule-scripting.xsd">


    <ajax:connector name="Ajax" serverUrl="http://0.0.0.0:9092/reservation" resourceBase="${app.home}/docroot" jsonCommented="true"    doc:name="Ajax" />

    <!-- 航班预定流，主要通过调用processReservation来完成航班信息的处理 -->
    <flow name="makeReservation">
        <ajax:inbound-endpoint channel="/searchFlights" connector-ref="Ajax" responseTimeout="10000" doc:name="Ajax" />
        <flow-ref name="processReservation" doc:name="processReservation"/>
    </flow>

    
    <!-- 
    航班预定信息处理流
        对航班的安排做的假设：
            航班号以3结尾，不可获得，直接抛出FlightUnavailableException异常
            航班号不是以3结尾，可进入下一步处理：
                航班号以2结尾，可取得座位信息'20A'；否则抛出没有座位信息异常'No seat info available'，并把'No seat info available'赋给座位信息部分            
     -->
    <flow name="processReservation">
    
        <json:json-to-object-transformer returnClass="org.mule.example.ReservationRequest" doc:name="JSON to ReservationRequest" />    
        
        <!-- 把请求的负载保存到session对象中（payload的类型为ReservationRequest） -->
        <set-session-variable variableName="reservationRequest" value="#[payload]" doc:name="Save orignal request in Session" />
        
        <!-- 设置响应消息的负载 -->
        <set-payload value="#[new org.mule.example.ReservationResponse()]" doc:name="Set ReservationResponse Payload" />
        
        <!-- 把请求消息中的flighs设置到响应消息中 （payload的类型为ReservationResponse） -->
        <expression-component doc:name="Add request flight to response">
            <![CDATA[payload.setFlights(reservationRequest.flights)]]>
        </expression-component>
        
        <set-variable variableName="totalPrice" value="#[0]" doc:name="Initialize totalPrice" /> <!-- 设置一个totalPrice变量，值为0 -->
        
        <!-- 迭代处理payload（payload的类型为ReservationResponse，里面有请求信息flights） -->
        <foreach collection="#[payload.flights]" doc:name="Foreach on flights">
            <scripting:transformer doc:name="Search flight availability">
                <scripting:script engine="Groovy"><![CDATA[
if (payload.flightNumber.endsWith('3'))
    throw new org.mule.example.FlightUnavailableException()
else
    payload]]>
                </scripting:script>
            </scripting:transformer>
            
            <!-- 
            此处声明了一个地址为vm://acquireFlightPriceQueue VM出站端点，即把响应消息扔到了acquireSeatsInfoQueue队列
            而acquireSeatsInfo流，在地址vm://acquireFlightPriceQueue上等待请求
            exchange-pattern="request-response" 表示该VM出站端点 等待acquireSeatsInfo流给的响应
            -->
            <vm:outbound-endpoint exchange-pattern="request-response" path="acquireSeatsInfoQueue" doc:name="Acquire Seats Info"/>
            <!-- 再把响应消息扔到了acquireFlightPriceQueue队列，等待响应 -->
            <vm:outbound-endpoint exchange-pattern="request-response" path="acquireFlightPriceQueue" doc:name="Acquire Flight Price" />
            
            <!-- 更新totalPrice变量的值，把本次迭代的票价加到总价中 -->
            <set-variable variableName="totalPrice" value="#[totalPrice + payload.ticketPrice]" doc:name="Add price to totalPrice" />
        </foreach>
        
        <expression-component doc:name="Add total price to reservation">
            <![CDATA[payload.totalPrice = flowVars['totalPrice']]]>
        </expression-component>
        <!-- 把响应对象转换为JSON, 航班预定处理结束 -->
        <json:object-to-json-transformer doc:name="Object to JSON" />
        
        
        <!-- 异常捕获区 -->
        <choice-exception-strategy doc:name="Choice Exception Strategy">    
            <!--  -->
            <catch-exception-strategy when="#[exception.causedBy(org.mule.example.FlightUnavailableException)]" doc:name="Catch Exception Strategy">
                <scripting:transformer doc:name="Add no avaiilability error">
                    <scripting:script engine="Groovy">
                        <![CDATA[
def payload = new org.mule.example.ReservationResponse()
payload.addError('There is no availability for the selected flight!')
payload]]>
                    </scripting:script>
                </scripting:transformer>
                <json:object-to-json-transformer doc:name="Object to JSON" />
            </catch-exception-strategy>
            
            <catch-exception-strategy doc:name="Catch Exception Strategy">
                <scripting:transformer doc:name="Add exception message">
                    <scripting:script engine="Groovy">
                        <![CDATA[                  
def payload = new org.mule.example.ReservationResponse()
payload.addError('Error processing request!')
payload]]>
                    </scripting:script>
                </scripting:transformer>
                <set-property propertyName="http.status" value="500" doc:name="Set http status 500" />
                <json:object-to-json-transformer doc:name="Object to JSON" />
            </catch-exception-strategy>
        </choice-exception-strategy>
    </flow>
    
    <!-- 
    应用启动时，该流服务随之启动，然后在vm://acquireFlightPriceQueue上等待请求
     -->
    <flow name="acquireSeatsInfo">
        <!-- 在acquireSeatsInfoQueue路径上等待输入座位信息 -->
        <vm:inbound-endpoint exchange-pattern="request-response" path="acquireSeatsInfoQueue" doc:name="VM"/>
        
        <!-- 使用脚本进行处理 -->
        <scripting:component doc:name="Acquire seats info service">
            <scripting:script engine="Groovy"><![CDATA[
if (payload.flightNumber.endsWith('2'))
    payload.seatInfo = '20A'
else
    throw new Exception('No seat info available')
payload]]></scripting:script>
        </scripting:component>
        
        <!-- 异常处理 -->
        <catch-exception-strategy doc:name="Catch Exception Strategy">
            <expression-component doc:name="Add no seat info available message"><![CDATA[payload.seatInfo = 'No seat info available']]></expression-component>    
        </catch-exception-strategy>
    </flow>
    
    
    <!-- 
    
    如：下面的path="acquireFlightPriceQueue"配置拼写不对
********************************************************************************
Message               : There is no receiver registered on connector "connector.VM.mule.default" for endpointUri vm://acquireFlightPriceQueue
Code                  : MULE_ERROR-0
在端点地址为vm://acquireFlightPriceQueue的连接器上没有注册接收者
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exception stack is:
1. There is no receiver registered on connector "connector.VM.mule.default" for endpointUri vm://acquireFlightPriceQueue (org.mule.api.transport.NoReceiverForEndpointException)
  org.mule.transport.vm.VMMessageDispatcher:85 (http://www.mulesoft.org/docs/site/current3/apidocs/org/mule/api/transport/NoReceiverForEndpointException.html)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Root Exception stack trace:
org.mule.api.transport.NoReceiverForEndpointException: There is no receiver registered on connector "connector.VM.mule.default" for endpointUri vm://acquireFlightPriceQueue
    at org.mule.transport.vm.VMMessageDispatcher.doSend(VMMessageDispatcher.java:85)
    at org.mule.transport.AbstractMessageDispatcher.process(AbstractMessageDispatcher.java:81)
    at org.mule.transport.AbstractConnector$DispatcherMessageProcessor.process(AbstractConnector.java:2627)
    + 3 more (set debug level logging or '-Dmule.verbose.exceptions=true' for everything)
********************************************************************************
    航班的票价计算怪怪的，编号*2： payload.ticketPrice = Integer.valueOf(payload.flightNumber) * 2
     -->
    <flow name="acquireFlightPrice">
        <vm:inbound-endpoint exchange-pattern="request-response" path="acquireFlightPriceQueue" doc:name="acquireFlightPrice"/>   
        <expression-component doc:name="acquireFlightPrice">
            <![CDATA[payload.ticketPrice = Integer.valueOf(payload.flightNumber) * 2]]>
        </expression-component>
    </flow>
</mule>

3 相关类定义

1）Flight -- 航班信息类

package org.mule.example;

import java.io.Serializable;

public class Flight implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = -841916700389246787L;

    private String flightNumber;
    private String seatInfo;
    private Double ticketPrice;

    public String getFlightNumber() {
        return flightNumber;
    }

    public void setFlightNumber(String flightNumber) {
        this.flightNumber = flightNumber;
    }

    public String getSeatInfo() {
        return seatInfo;
    }

    public void setSeatInfo(String seatInfo) {
        this.seatInfo = seatInfo;
    }

    public Double getTicketPrice() {
        return ticketPrice;
    }

    public void setTicketPrice(Double ticketPrice) {
        this.ticketPrice = ticketPrice;
    }
}

2）ReservationRequest -- 请求消息负载内容类

package org.mule.example;

import java.io.Serializable;

public class ReservationRequest implements Serializable {
    
    /**
     * 
     */
    private static final long serialVersionUID = 3502244785792589115L;
    
    private Flight[] flights;
    
    public Flight[] getFlights() {
        return flights;
    }
    
    public void setFlights(Flight[] flights) {
        this.flights = flights;
    }
}

3）ReservationResponse 响应消息负载内容类

package org.mule.example;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class ReservationResponse implements Serializable {
    
    private List<String> errors = new ArrayList<String>();
    
    private Flight[] flights;
    public Double totalPrice;
    
    
    public Double getTotalPrice() {
        return totalPrice;
    }
    public void setTotalPrice(Double totalPrice) {
        this.totalPrice = totalPrice;
    }

    public List<String> getErrors() {
        return errors;
    }
    public void setErrors(List<String> errors) {
        this.errors = errors;
    }

    public Flight[] getFlights() {
        return flights;
    }
    public void setFlights(Flight[] flights) {
        this.flights = flights;
    }
    
    //------ 添加错误信息---------------------
    public void addError(String error) {
        errors.add(error);
    }
    
    //------- 原始请求对象---------------------
    private ReservationRequest originalRequest;


    public ReservationRequest getOriginalRequest() {
        return originalRequest;
    }

    public void setOriginalRequest(ReservationRequest originalRequest) {
        this.originalRequest = originalRequest;
    }
}

4）FlightUnavailableException 异常类

package org.mule.example;

public class FlightUnavailableException extends Exception {

}

4 Ajax访问页面

1）index.html

<!DOCTYPE html>
<html>
<head>
    <link href="flight-reservation.css" rel="stylesheet" type="text/css"/>
    <script type="text/javascript" src="mule-resource/js/mule.js"></script>
    <script type="text/javascript" src="flight-reservation.js"></script>
</head>
<body onload="onload();">
<div class="content">
    <div class="flightReservationHeader"> Flight Reservation System </div>
    <div id="title"> Search Best Flight </div>
    <div class="searchBox">
        <form id="searchFlight">
            <div class="cities">
                <div id="origin">
                    <div>Origin</div>
                    <select class="origin" id="originCity">
                        <option value=""></option>
                        <option value="BUE">Buenos Aires (BUE)</option>
                    </select>
                </div>
                <div id="destination">
                    <div>Destination</div>
                    <select class="destination" id="destinationCity">
                        <option value=""></option>
                        <option value="MOW">Moscu (MOW) </option>
                        <option value="HKG">Hong Kong (HKG) </option>
                        <option value="TW">Tai Wang (TW)</option>
                    </select>
                </div>
            </div>
        </form>
        <div id="makeSearch">
            <input id="searchButton" type="button" value="Search" onClick="makeSearch(dojo.byId('originCity').value, dojo.byId('destinationCity').value)">
        </div>
    </div>
    <div class="response">
        <div id="error"><div id="errorMessage"></div></div>
        <div id="searchResults"></div>
    </div>
</div>
</body>
</html>

2) flight-reservation.js

function onload() {
    dojo.byId("error").style.display = "none";
    dojo.byId("searchResults").style.display = "none";
}

//发送航班请求
function makeSearch(origin, destination) {
    var request="";
        
    if (origin == "BUE" && destination == "MOW") 
    {
        
        var request = {
                "flights": [
                        {"flightNumber":912},
                        {"flightNumber":1022},
                        {"flightNumber":732}
                           ]
                    };
        mule.rpc("/searchFlights", JSON.stringify(request), processResponse);    
    } 
    else if (origin == "BUE" && destination == "HKG") 
    {
        var request = {
                "flights":[
                        {"flightNumber":822},
                        {"flightNumber":1133}
                          ]
                    };
        mule.rpc("/searchFlights", JSON.stringify(request), processResponse);
    } 
    else if (origin == "BUE" && destination == "TW")
    {
        var request = {
                "flights":[
                        {"flightNumber":822},
                        {"flightNumber":1004}
                          ]
                    };
        mule.rpc("/searchFlights", JSON.stringify(request), processResponse);
    }
    else 
    {
        var request={"Invalid Request":[]};
        mule.rpc("/searchFlights", JSON.stringify(request), processResponse);
    }
}


//处理响应
function processResponse(message) {
    resp = JSON.parse("[" + message.data + "]")[0];
    
    if(resp.errors == "") 
    {
        dojo.byId("error").style.display = "none";
        dojo.byId("searchResults").style.display = "block";

        var results = "<table class='results'>";
        results += "<th>Flight Number</th><th>Seat assignment</th><th>Price</th>"
        
        for(var i = 0; i < resp.flights.length;i++) 
        {
            results +="<tr><td>" + resp.flights[i].flightNumber + "</td><td>" + resp.flights[i].seatInfo + "</td><td>$" + resp.flights[i].ticketPrice + "</td></tr>";
        }
        
        results += "<tr><td colspan='3'><div id='totalPrice'>Total price is $" + resp.totalPrice + "</div></td><tr>"
        results += "</table>";

        dojo.byId("searchResults").innerHTML = results;
    } 
    else 
    {
        dojo.byId("error").style.display = "block";
        dojo.byId("searchResults").style.display = "none";
        dojo.byId("errorMessage").innerHTML = resp.errors;
    }
}

3) flight-reservation.css

.content {
    padding: 20px 0 20px 50px;
    width: 620px;
    color: #003399;
    background-color: #F8F8FF
}

.flightReservationHeader {
    text-align: center;
    font-weight: bold;
    padding-bottom: 20px;
    font-size: 1.8em;
}

#title {
    padding-top: 5px;
    font-weight: bold;
    background-color: #E8EDFF;
    width: 150px;
    height: 25px;
    border: 2px solid #B9C9FE;
    text-align: center
}

.searchBox {
    width: 550px;
    background-color: #E8EDFF;
    border: 2px solid #B9C9FE;
    position: relative;
    padding-bottom: 30px;
    padding-top: 20px
}

.cities {
    padding: 10px 35px 10px 35px
}

#origin {
    float: left;
    padding-right: 50px
}

.origin {
    width: 215px
}

.destination {
    width: 215px
}

#destination {
    float: left
}

#makeSearch {
    clear: both;
    padding: 20px 0 10px 40px;
    position: relative;
}

#searchButton {
    background-color: #B9C9FE
}

#error {
    width: 550px;
    height: 50px;
    color: #FF0000;
    text-align: center;
    background-color: #FFDAB9;
    border: 2px solid #FF0000;
    display: none
}

#errorMessage {
    padding: 10px
}

.response {
    padding-top: 30px
}

.response table {
    width: 550px;
}

.response table th {
    background: none repeat scroll 0 0 #B9C9FE;
    border-bottom: 1px solid #FFFFFF;
    border-top: 4px solid #AABCFE;
    color: #003399;
    padding: 8px
}

.response table td {
    background: none repeat scroll 0 0 #E8EDFF;
    border-bottom: 1px solid #FFFFFF;
    border-top: 1px solid transparent;
    color: #666699;
    padding: 8px;
}

#totalPrice {
    float: right;
    font-weight: bold
}

5 执行效果分析

1）flights编号都以'2'结尾，所以正常运行

2）该请求包含了一个以'3'结尾的航班编号，触发该航班不可得异常

3）尾号为2的航班，分配的座位都是'20A'；尾号为3的航班，不可得；尾号不是2、3的航班没座位