Programming Design Notes

Google 剛剛出的新服務 - Google Cloud SQL，可能有太多人抱怨認為 Google App Engine 的 Datastore 太難用，而且現有的 App 移植到 Google App Engine 最大問題也是 Datastore。傳統的應用程式大多數使用 Relational Database Management System (RDBMS) 關聯式資料庫管理系統作為儲存資料的系統，但 RDBMS 是比較難去擴展整個系統，起初可以靠升級系統硬件去加強效能，但硬件升級愈高，性價比愈低。而 Google App Engine 的 Datastore 是 NoSQL Database，擴展系統是一件很容易的事，可以買 5 台中級機器去組成整個系統，不夠可以再加上去，可以無限地伸延 (理論上)。NoSQL Database 是沒有 Join Table 之類的語法，你只能靠應用程式層面實現 Join Table，這會提高應用程式開發難度。

Google Cloud SQL 是用來解決傳統的應用程式移植或對使用 RDBMS 有開發經驗的程式員有多一個選擇。而 Google Cloud SQL 底層是使用 MySQL 實作的。

打開 Google Cloud SQL 的 Console 是這個樣子:

而容量方面有三個選擇，分別是 1GB, 5GB 和 10GB
試試新增一個 MySQL Instance (暫時只有 Google App Engine 可以存取到，只需加入 GAE 的 ID 就可以了):

處理中:

完成後看一看 Log:

再到 Prompt 看看:

新增一個 Database，命名為 mydb:

再新增一個 Table 命名為 User:

我發現每一次只可以輸入一行指令，有分號隔著也不行，希望遲點會改善。
當然 Google Cloud SQL 有提供 Import 的功能，但檔案一定要存放在 Google Cloud Storage 上。




Import 成功後就試試旗選取一埋資料:

再試試 Join Table:

一樣沒有問題。

SQL 檔案: sampledatabase.sql

要申請 Google Cloud SQL 可到 https://code.google.com/apis/console/，然後選取 Service 再在 Google Cloud SQL 按一下 Request access，填好表格後就等 Google 回覆就可以用了 (我是等了兩天才有回覆)。
遲一點再在 GAE 上試用。

以前我喜歡使用 Spring + Spring Web MVC 來打造 RESTful 應用程式，但 Spring 的起動有點慢，如果放上 Google App Engine 上經常令用戶等待很久才載入到頁面。

今次選用了 Guice + Jersey 的組合。Guice 是一個輕量級的容器，設定上比起 Spring 更簡單，起動或注入速度亦比 Spring 快。而 Jersey 則是一個為 RESTful web service 而設的一個 Framework。

Gucie 官方網址: http://code.google.com/p/google-guice/
Jersey 官方網址: http://jersey.java.net/

因為手上的電腦沒有安裝 Application Server，只好拿 GAE 的 Development Server 來測試。

首先下載 Guice : http://code.google.com/p/google-guice/downloads/detail?name=guice-3.0.zip&can=2&q= (現時為止最新版本為 3.0)

打開後將 aopalliance.jar, guice-3.0.jar, guice-servlet-3.0.jar 和 javax.inject.jar 加到 WEB-INF/lib 中並加到 Class path。

然後下載 Jersey 所需的 Jar (現時為止最新版本為 1.9):

1. jersey-server.jar
2. jersey-core.jar
3. asm.jar
4. jersey-guice-1.9-SNAPSHOT.jar

將以上的檔案一樣是放到 WEB-INF/lib 並加到 Class path。

首先建立一個 class，每一次連接 http://www.xyzdomainname.com 都會顯示 I am Index page:

package com.ctlok.pro.controller;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/")
public class CommonController {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String index(){
        return "I am Index page";
    }
    
}

@Path 是設定這個 class 會處理的 URL，可以放在 Class 或 Method。而 Jersey 會搜尋出在 Class 上有 @Path 的類別然後處理。
@GET 是設定這個 Method 處理那一種請求，一共有 5 種方式: GET, POST, HEAD, PUT, DELETE。
@Produces 則是回傳資料的類型，可以是 Text, XML, JSON, HTML 等等。

然後再去建立一個 Guice 的 Module class 並設定 Jersey:

package com.ctlok.pro;

import java.util.HashMap;
import java.util.Map;

import com.ctlok.pro.controller.CommonController;
import com.google.inject.servlet.RequestScoped;
import com.google.inject.servlet.ServletModule;
import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;

public class WebModule extends ServletModule {

    @Override
    protected void configureServlets(){
        bind(CommonController.class).in(RequestScoped.class);
        
        Map<String, String> parameters = new HashMap<String, String>(); 
        parameters.put("com.sun.jersey.config.property.packages", "com.ctlok.pro.controller");
        serve("/*").with(GuiceContainer.class, parameters);
    }
    
}

然後設定 Guice 起動時的注入器:

package com.ctlok.pro;

import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.servlet.GuiceServletContextListener;

public class AppConfig extends GuiceServletContextListener{

    @Override
    protected Injector getInjector() {
        return Guice.createInjector(new WebModule());
    }

}

在 web.xml 設定好 Guice Filter和 Listener:

<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
 <listener>
  <listener-class>com.ctlok.pro.AppConfig</listener-class>
 </listener>
 <filter>
  <filter-name>guiceFilter</filter-name>
  <filter-class>com.google.inject.servlet.GuiceFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>guiceFilter</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>
</web-app>

打開 http://localhost:8888 後即可看到 “I am Index page”.

如要增加 URL，可以在 CommonController 加入:

@GET
@Path("user/{userId}/{userName}")
@Produces(MediaType.TEXT_PLAIN)
public String getUser(@PathParam("userId") String userId, @PathParam("userName") String userName){
    return "User ID: " + userId + ", user name: " + userName;
}

你可能有點疑問，@Path 在 Class 已經設家了，現在又有一個 @Path 在 method 上，那 Jersey 會怎麼決定。
其實 Jersey 會將 class 的 @Path value 加上 method 的 @Path value，即是 “/” + “user/{userId}/{userName}”。

打開 http://localhost:8888/user/123/lawrence 顯示:User ID: 123, user name: lawrence

其實 Jersey 的 Method 不一定返回 String 可以是一個 Object 或 Jersey 定義 的 Response。以下例字示範如何顯示一個 JSP 頁面，並由 Controller 將 Model 傳給 View (JSP):

先在 WEB-INF 新增一個 views 資料夾並新增一個 example.jsp，JSP 內容如下:

<?xml version="1.0" encoding="utf-8"?>
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>Guice + Jersey + JSP</title>
 </head>
 <body>
  <c:out value="${it.msg}" />
 </body>
</html>

在 Controller 內也增加一個 Method:

@GET
@Path("jsp")
@Produces(MediaType.TEXT_HTML)
public Response getJsp(){
    Map<String, Object> model = new HashMap<String, Object>();
    model.put("msg", "Hello World!");
    return Response.ok(new Viewable("/WEB-INF/views/example.jsp", model)).build();
}

打開 http://localhost:8888/jsp 顯示: Hello World!

完整的 CommonController:

package com.ctlok.pro.controller;

import java.util.HashMap;
import java.util.Map;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.sun.jersey.api.view.Viewable;

@Path("/")
public class CommonController {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String index() {
        return "I am Index page";
    }

    @GET
    @Path("user/{userId}/{userName}")
    @Produces(MediaType.TEXT_PLAIN)
    public String getUser(@PathParam("userId") String userId,
            @PathParam("userName") String userName) {
        return "User ID: " + userId + ", user name: " + userName;
    }

    @GET
    @Path("jsp")
    @Produces(MediaType.TEXT_HTML)
    public Response getJsp() {
        Map<String, Object> model = new HashMap<String, Object>();
        model.put("msg", "Hello World!");
        return Response.ok(new Viewable("/WEB-INF/views/example.jsp", model))
                .build();
    }

}

範例: Guice-Jersey.zip
密碼: pro.ctlok.com 相關書籍:

在公司有個項目是使用 JSF 作為 View，感覺十分差。JSF 給我的感覺: 運行慢，吃資源，限制又多。實在不太喜歡 JSF。

在進行 Street Test 時，發覺 Server 上的 Memory 用得異常地多。經調查後發現 RichFaces 其中一個 Object - AjaxStateHolder 佔用大量 Memory。如果是使用 3.2.0.SR1 之前的版本更加嚴重，Session 隨時佔用 1 Gigabytes 的 Memory。

解決方法就是在 web.xml 加入以下設定:

<context-param>
    <param-name>com.sun.faces.numberOfViewsInSession</param-name>
    <param-value>1</param-value>
</context-param>

<context-param>
    <param-name>com.sun.faces.numberOfLogicalViews</param-name>
    <param-value>1</param-value>
</context-param>

因為每運行一次 JSF 的 View 時都會將這個 View 放到 Session 內，而且同一個 View 亦會再儲存多一次在 Session，因為這些 Session 仍然在使用中，JVM GC 無法將不用的 View 回收，做成 Memory 使用量不斷增加。

限制 View 數量後就可以解決這個問題。

RichFaces bug: https://issues.jboss.org/browse/RF-3878

相關書籍:

上一篇已經介紹過使用 Bottom Up 的方法來開發 Web Service: Java 使用 Bottom Up 和 JAX-WS 來部署 Web Service。今次當然是使用 Top Down 的方法，個人認為 Top Down 其實比 Bottom Up 方法更好，原因是自動產生出來的 XML Schema 和 WSDL 不太好。雖然是方便，但有很多細節地方不能自己操作到，所以我是比較喜歡 Top Down 的。


使用 Top Down 一定要懂 XML Schema 和 Web Services Description Language。

XML Schema: http://www.w3schools.com/schema/default.asp
Web Services Description Language: http://www.w3schools.com/WSDL/default.asp

這次的 Web Service 功能是客戶端 (Web service client) 送出一個 Employee Id list 到 服務器端 (Web service provider)。

首先建立一個 WAR project，然後在 web root 目錄 加入 company.xsd 和 company.wsdl。

以下是 company.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://pro.ctlok.com/company" xmlns:tns="http://pro.ctlok.com/company"
    elementFormDefault="qualified">

    <xs:simpleType name="EmployeeId">
        <xs:restriction base="xs:string">
            <xs:length value="7" />
            <xs:pattern value="E[0-9]{7}" />
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="EmployeeTitle">
        <xs:restriction base="xs:string">
            <xs:enumeration value="CEO" />
            <xs:enumeration value="Manger" />
            <xs:enumeration value="Supervisor" />
            <xs:enumeration value="Clerk" />
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="EmployeeInfo">
        <xs:sequence>
            <xs:element name="eid" type="tns:EmployeeId"
                minOccurs="0" nillable="false" />
            <xs:element name="firstName" type="xs:string"
                minOccurs="0" nillable="false" />
            <xs:element name="lastName" type="xs:string"
                minOccurs="0" nillable="false" />
            <xs:element name="age" type="xs:unsignedShort"
                minOccurs="0" nillable="false" />
            <xs:element name="title" type="tns:EmployeeTitle"
                minOccurs="0" nillable="false" />
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="EmployeeInfoWrapper">
        <xs:sequence>
            <xs:element name="employeeInfo" type="tns:EmployeeInfo"
                minOccurs="0" maxOccurs="unbounded" nillable="false" />
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="EmployeeIdWrapper">
        <xs:sequence>
            <xs:element name="eid" type="tns:EmployeeId"
                minOccurs="0" maxOccurs="unbounded" nillable="false" />
        </xs:sequence>
    </xs:complexType>

    <xs:element name="EmployeeIdList" type="tns:EmployeeIdWrapper" />
    <xs:element name="EmployeeInfoList" type="tns:EmployeeInfoWrapper" />

</xs:schema>

以下則是 company.wsdl:

<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions name="Company" targetNamespace="http://pro.ctlok.com/company"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://pro.ctlok.com/company"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    
    <wsdl:types>
        <xsd:schema>
            <xsd:import namespace="http://pro.ctlok.com/company"
                schemaLocation="company.xsd" />
        </xsd:schema>
    </wsdl:types>
    
    <wsdl:message name="employeeLookupRequest">
        <wsdl:part element="tns:EmployeeIdList" name="employeeIdList" />
    </wsdl:message>
    
    <wsdl:message name="employeeLookupResponse">
        <wsdl:part element="tns:EmployeeInfoList" name="employeeInfoList" />
    </wsdl:message>
    
    <wsdl:portType name="employeeLookupService">
        <wsdl:operation name="employeeLookup">
            <wsdl:input message="tns:employeeLookupRequest" />
            <wsdl:output message="tns:employeeLookupResponse" />
        </wsdl:operation>
    </wsdl:portType>
    
    <wsdl:binding name="employeeLookupBinding" type="tns:employeeLookupService">
        <soap:binding style="document"
            transport="http://schemas.xmlsoap.org/soap/http" />
        <wsdl:operation name="employeeLookup">
            <soap:operation
                soapAction="http://pro.ctlok.com/company/employeeLookup" />
            <wsdl:input>
                <soap:body use="literal" />
            </wsdl:input>
            <wsdl:output>
                <soap:body use="literal" />
            </wsdl:output>
        </wsdl:operation>
    </wsdl:binding>
    
    <wsdl:service name="employeeLookupService">
        <wsdl:port binding="tns:employeeLookupBinding" name="employeeLookupPort">
            <soap:address location="http://localhost:9080/WebService" />
        </wsdl:port>
    </wsdl:service>
    
</wsdl:definitions>

現在完成了 Web Service 的介面了，但要將 Web Service 的 Object 轉為 Java Class 才可以。幸好有工具可以替我們完成這項工作，不用一個一個手動建立。使用 JAXB compiler 幫我們將 WSDL 內用到的 Object 轉為 Java Class。在 Windows 打開 CMD 輸入以下指令:

xjc -wsdl company.wsdl -p com.ctlok.pro.ws.model

*** 如果你不能執行 xjc，請查看 System Path 有沒有加入 %JAVA_HOME%/bin 。 ***

• -wsdl 是 wsdl 檔案存放的位置
• -p 是產生出來的 Java class 所在 package

想知更多指令可參考: JAXB Using

執行指令後會看到有 6 個 .java 檔案，分別是:

1. EmployeeIdWrapper
2. EmployeeInfo
3. EmployeeInfoWrapper
4. EmployeeTitle
5. ObjectFactory
6. package-info

EmployeeIdWrapper:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//


package com.ctlok.pro.ws.model;

import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;


/**
 * <p>Java class for EmployeeIdWrapper complex type.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * 
 * <pre>
 * &lt;complexType name="EmployeeIdWrapper">
 *   &lt;complexContent>
 *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *       &lt;sequence>
 *         &lt;element name="eid" type="{http://pro.ctlok.com/company}EmployeeId" maxOccurs="unbounded" minOccurs="0"/>
 *       &lt;/sequence>
 *     &lt;/restriction>
 *   &lt;/complexContent>
 * &lt;/complexType>
 * </pre>
 * 
 * 
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "EmployeeIdWrapper", propOrder = {
    "eid"
})
public class EmployeeIdWrapper {

    protected List<String> eid;

    /**
     * Gets the value of the eid property.
     * 
     * <p>
     * This accessor method returns a reference to the live list,
     * not a snapshot. Therefore any modification you make to the
     * returned list will be present inside the JAXB object.
     * This is why there is not a <CODE>set</CODE> method for the eid property.
     * 
     * <p>
     * For example, to add a new item, do as follows:
     * <pre>
     *    getEid().add(newItem);
     * </pre>
     * 
     * 
     * <p>
     * Objects of the following type(s) are allowed in the list
     * {@link String }
     * 
     * 
     */
    public List<String> getEid() {
        if (eid == null) {
            eid = new ArrayList<String>();
        }
        return this.eid;
    }

}

EmployeeInfo:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//


package com.ctlok.pro.ws.model;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlSchemaType;
import javax.xml.bind.annotation.XmlType;


/**
 * <p>Java class for EmployeeInfo complex type.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * 
 * <pre>
 * &lt;complexType name="EmployeeInfo">
 *   &lt;complexContent>
 *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *       &lt;sequence>
 *         &lt;element name="eid" type="{http://pro.ctlok.com/company}EmployeeId" minOccurs="0"/>
 *         &lt;element name="firstName" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
 *         &lt;element name="lastName" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
 *         &lt;element name="age" type="{http://www.w3.org/2001/XMLSchema}unsignedShort" minOccurs="0"/>
 *         &lt;element name="title" type="{http://pro.ctlok.com/company}EmployeeTitle" minOccurs="0"/>
 *       &lt;/sequence>
 *     &lt;/restriction>
 *   &lt;/complexContent>
 * &lt;/complexType>
 * </pre>
 * 
 * 
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "EmployeeInfo", propOrder = {
    "eid",
    "firstName",
    "lastName",
    "age",
    "title"
})
public class EmployeeInfo {

    protected String eid;
    protected String firstName;
    protected String lastName;
    @XmlSchemaType(name = "unsignedShort")
    protected Integer age;
    protected EmployeeTitle title;

    /**
     * Gets the value of the eid property.
     * 
     * @return
     *     possible object is
     *     {@link String }
     *     
     */
    public String getEid() {
        return eid;
    }

    /**
     * Sets the value of the eid property.
     * 
     * @param value
     *     allowed object is
     *     {@link String }
     *     
     */
    public void setEid(String value) {
        this.eid = value;
    }

    /**
     * Gets the value of the firstName property.
     * 
     * @return
     *     possible object is
     *     {@link String }
     *     
     */
    public String getFirstName() {
        return firstName;
    }

    /**
     * Sets the value of the firstName property.
     * 
     * @param value
     *     allowed object is
     *     {@link String }
     *     
     */
    public void setFirstName(String value) {
        this.firstName = value;
    }

    /**
     * Gets the value of the lastName property.
     * 
     * @return
     *     possible object is
     *     {@link String }
     *     
     */
    public String getLastName() {
        return lastName;
    }

    /**
     * Sets the value of the lastName property.
     * 
     * @param value
     *     allowed object is
     *     {@link String }
     *     
     */
    public void setLastName(String value) {
        this.lastName = value;
    }

    /**
     * Gets the value of the age property.
     * 
     * @return
     *     possible object is
     *     {@link Integer }
     *     
     */
    public Integer getAge() {
        return age;
    }

    /**
     * Sets the value of the age property.
     * 
     * @param value
     *     allowed object is
     *     {@link Integer }
     *     
     */
    public void setAge(Integer value) {
        this.age = value;
    }

    /**
     * Gets the value of the title property.
     * 
     * @return
     *     possible object is
     *     {@link EmployeeTitle }
     *     
     */
    public EmployeeTitle getTitle() {
        return title;
    }

    /**
     * Sets the value of the title property.
     * 
     * @param value
     *     allowed object is
     *     {@link EmployeeTitle }
     *     
     */
    public void setTitle(EmployeeTitle value) {
        this.title = value;
    }

}

EmployeeInfoWrapper:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//


package com.ctlok.pro.ws.model;

import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;


/**
 * <p>Java class for EmployeeInfoWrapper complex type.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * 
 * <pre>
 * &lt;complexType name="EmployeeInfoWrapper">
 *   &lt;complexContent>
 *     &lt;restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
 *       &lt;sequence>
 *         &lt;element name="employeeInfo" type="{http://pro.ctlok.com/company}EmployeeInfo" maxOccurs="unbounded" minOccurs="0"/>
 *       &lt;/sequence>
 *     &lt;/restriction>
 *   &lt;/complexContent>
 * &lt;/complexType>
 * </pre>
 * 
 * 
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "EmployeeInfoWrapper", propOrder = {
    "employeeInfo"
})
public class EmployeeInfoWrapper {

    protected List<EmployeeInfo> employeeInfo;

    /**
     * Gets the value of the employeeInfo property.
     * 
     * <p>
     * This accessor method returns a reference to the live list,
     * not a snapshot. Therefore any modification you make to the
     * returned list will be present inside the JAXB object.
     * This is why there is not a <CODE>set</CODE> method for the employeeInfo property.
     * 
     * <p>
     * For example, to add a new item, do as follows:
     * <pre>
     *    getEmployeeInfo().add(newItem);
     * </pre>
     * 
     * 
     * <p>
     * Objects of the following type(s) are allowed in the list
     * {@link EmployeeInfo }
     * 
     * 
     */
    public List<EmployeeInfo> getEmployeeInfo() {
        if (employeeInfo == null) {
            employeeInfo = new ArrayList<EmployeeInfo>();
        }
        return this.employeeInfo;
    }

}

EmployeeTitle:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//


package com.ctlok.pro.ws.model;

import javax.xml.bind.annotation.XmlEnum;
import javax.xml.bind.annotation.XmlEnumValue;
import javax.xml.bind.annotation.XmlType;


/**
 * <p>Java class for EmployeeTitle.
 * 
 * <p>The following schema fragment specifies the expected content contained within this class.
 * <p>
 * <pre>
 * &lt;simpleType name="EmployeeTitle">
 *   &lt;restriction base="{http://www.w3.org/2001/XMLSchema}string">
 *     &lt;enumeration value="CEO"/>
 *     &lt;enumeration value="Manger"/>
 *     &lt;enumeration value="Supervisor"/>
 *     &lt;enumeration value="Clerk"/>
 *   &lt;/restriction>
 * &lt;/simpleType>
 * </pre>
 * 
 */
@XmlType(name = "EmployeeTitle")
@XmlEnum
public enum EmployeeTitle {

    CEO("CEO"),
    @XmlEnumValue("Manger")
    MANGER("Manger"),
    @XmlEnumValue("Supervisor")
    SUPERVISOR("Supervisor"),
    @XmlEnumValue("Clerk")
    CLERK("Clerk");
    private final String value;

    EmployeeTitle(String v) {
        value = v;
    }

    public String value() {
        return value;
    }

    public static EmployeeTitle fromValue(String v) {
        for (EmployeeTitle c: EmployeeTitle.values()) {
            if (c.value.equals(v)) {
                return c;
            }
        }
        throw new IllegalArgumentException(v);
    }

}

ObjectFactory:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//


package com.ctlok.pro.ws.model;

import javax.xml.bind.JAXBElement;
import javax.xml.bind.annotation.XmlElementDecl;
import javax.xml.bind.annotation.XmlRegistry;
import javax.xml.namespace.QName;


/**
 * This object contains factory methods for each 
 * Java content interface and Java element interface 
 * generated in the com.ctlok.pro.ws.model package. 
 * <p>An ObjectFactory allows you to programatically 
 * construct new instances of the Java representation 
 * for XML content. The Java representation of XML 
 * content can consist of schema derived interfaces 
 * and classes representing the binding of schema 
 * type definitions, element declarations and model 
 * groups.  Factory methods for each of these are 
 * provided in this class.
 * 
 */
@XmlRegistry
public class ObjectFactory {

    private final static QName _EmployeeIdList_QNAME = new QName("http://pro.ctlok.com/company", "EmployeeIdList");
    private final static QName _EmployeeInfoList_QNAME = new QName("http://pro.ctlok.com/company", "EmployeeInfoList");

    /**
     * Create a new ObjectFactory that can be used to create new instances of schema derived classes for package: com.ctlok.pro.ws.model
     * 
     */
    public ObjectFactory() {
    }

    /**
     * Create an instance of {@link EmployeeIdWrapper }
     * 
     */
    public EmployeeIdWrapper createEmployeeIdWrapper() {
        return new EmployeeIdWrapper();
    }

    /**
     * Create an instance of {@link EmployeeInfoWrapper }
     * 
     */
    public EmployeeInfoWrapper createEmployeeInfoWrapper() {
        return new EmployeeInfoWrapper();
    }

    /**
     * Create an instance of {@link EmployeeInfo }
     * 
     */
    public EmployeeInfo createEmployeeInfo() {
        return new EmployeeInfo();
    }

    /**
     * Create an instance of {@link JAXBElement }{@code <}{@link EmployeeIdWrapper }{@code >}}
     * 
     */
    @XmlElementDecl(namespace = "http://pro.ctlok.com/company", name = "EmployeeIdList")
    public JAXBElement<EmployeeIdWrapper> createEmployeeIdList(EmployeeIdWrapper value) {
        return new JAXBElement<EmployeeIdWrapper>(_EmployeeIdList_QNAME, EmployeeIdWrapper.class, null, value);
    }

    /**
     * Create an instance of {@link JAXBElement }{@code <}{@link EmployeeInfoWrapper }{@code >}}
     * 
     */
    @XmlElementDecl(namespace = "http://pro.ctlok.com/company", name = "EmployeeInfoList")
    public JAXBElement<EmployeeInfoWrapper> createEmployeeInfoList(EmployeeInfoWrapper value) {
        return new JAXBElement<EmployeeInfoWrapper>(_EmployeeInfoList_QNAME, EmployeeInfoWrapper.class, null, value);
    }

}

package-info:

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.3 in JDK 1.6 
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> 
// Any modifications to this file will be lost upon recompilation of the source schema. 
// Generated on: 2011.06.23 at 04:28:35 PM CST 
//

@javax.xml.bind.annotation.XmlSchema(namespace = "http://pro.ctlok.com/company", elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)
package com.ctlok.pro.ws.model;

將這些 Java Class 複製到 WAR project 內。

再建立一個 Java Class - EmployeeLookupService:

package com.ctlok.pro.ws;

import java.util.HashMap;
import java.util.Map;

import javax.jws.WebMethod;
import javax.jws.WebParam;
import javax.jws.WebResult;
import javax.jws.WebService;
import javax.jws.soap.SOAPBinding;
import javax.xml.bind.annotation.XmlSeeAlso;

import com.ctlok.pro.ws.model.EmployeeIdWrapper;
import com.ctlok.pro.ws.model.EmployeeInfo;
import com.ctlok.pro.ws.model.EmployeeInfoWrapper;
import com.ctlok.pro.ws.model.EmployeeTitle;
import com.ctlok.pro.ws.model.ObjectFactory;

@WebService(
        name = "employeeLookupService", 
        serviceName = "employeeLookupService", 
        portName = "employeeLookupPort", 
        targetNamespace= "http://pro.ctlok.com/company",
        wsdlLocation = "company.wsdl")
@SOAPBinding(parameterStyle = SOAPBinding.ParameterStyle.BARE)
@XmlSeeAlso({ObjectFactory.class})
public class EmployeeLookupService {
    
    private Map<String, EmployeeInfo> infoMap;
    
    public EmployeeLookupService(){
        infoMap = new HashMap<String, EmployeeInfo>();
        
        EmployeeInfo info1 = new EmployeeInfo();
        info1.setEid("E1000000");
        info1.setFirstName("Lawrence");
        info1.setLastName("Cheung");
        info1.setAge(24);
        info1.setTitle(EmployeeTitle.CEO);
        
        EmployeeInfo info2 = new EmployeeInfo();
        info2.setEid("E1524125");
        info2.setFirstName("Tom");
        info2.setLastName("Wong");
        info2.setAge(22);
        info2.setTitle(EmployeeTitle.CLERK);
        
        EmployeeInfo info3 = new EmployeeInfo();
        info3.setEid("E7452145");
        info3.setFirstName("John");
        info3.setLastName("Lee");
        info3.setAge(29);
        info3.setTitle(EmployeeTitle.MANGER);
        
        EmployeeInfo info4 = new EmployeeInfo();
        info4.setEid("E6523547");
        info4.setFirstName("Katty");
        info4.setLastName("Choi");
        info4.setAge(24);
        info4.setTitle(EmployeeTitle.SUPERVISOR);
        
        
        infoMap.put(info1.getEid(), info1);
        infoMap.put(info2.getEid(), info2);
        infoMap.put(info3.getEid(), info3);
        infoMap.put(info4.getEid(), info4);
    }

    @WebMethod(operationName="employeeLookup")
    @WebResult(name = "EmployeeInfoList", partName = "employeeInfoList")
    public EmployeeInfoWrapper employeeLookup(
            @WebParam(name = "EmployeeIdList", partName = "employeeIdList") 
            EmployeeIdWrapper employeeIdWrapper){
        
        EmployeeInfoWrapper employeeInfoWrapper = new EmployeeInfoWrapper();
        
        for (String eid: employeeIdWrapper.getEid()){
            EmployeeInfo info = infoMap.get(eid);
            
            if (info == null)
                info = new EmployeeInfo();
            
            employeeInfoWrapper.getEmployeeInfo().add(info);
        }
        
        return employeeInfoWrapper;
        
    }

}

完成了 Web Service Provider。

@SOAPBinding(parameterStyle = SOAPBinding.ParameterStyle.BARE)

以上這句注解很重要，預設是 WRAPPED，即是 JAX-WS 會替你自動包裝好 List Object，但我們在 XML Schema 已經設定了 Wrapper，所以不用設定為 WRAPPED。

————– 分隔線 ————–

@XmlSeeAlso({ObjectFactory.class})

以上的注解則是確保 JAXB 正常運作，由 XML 轉為 Object 或 Object 轉為 XML。

————– 分隔線 ————–

@WebResult(name = "EmployeeInfoList", partName = "employeeInfoList")

以上的注解對應 WSDL 內的:

<wsdl:message name="employeeLookupRequest">
    <wsdl:part element="tns:EmployeeIdList" name="employeeIdList" />
</wsdl:message>

————– 分隔線 ————–

@WebResult(name = "EmployeeInfoList", partName = "employeeInfoList")

以上的注解則對應 WSDL 內的:

<wsdl:message name="employeeLookupResponse">
    <wsdl:part element="tns:EmployeeInfoList" name="employeeInfoList" />
</wsdl:message>

現在將 WAR project 放上 Application Server 並運行 http://localhost/employeeLookupService?wsdl。如果發現找不到 wsdl 檔案即是 wsdl 放的位置不正確。

成功找到後可以使用 soapUI 去測試一下，傳送以下 SOAP XML 到 Server:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:com="http://pro.ctlok.com/company">
   <soapenv:Header/>
   <soapenv:Body>
      <com:EmployeeIdList>
         <!--Zero or more repetitions:-->
         <com:eid>E1000000</com:eid>
         <com:eid>E1524125</com:eid>
      </com:EmployeeIdList>
   </soapenv:Body>
</soapenv:Envelope>

Server 回傳以下 XML 即代表成功設定:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
   <soapenv:Body>
      <EmployeeInfoList xmlns="http://pro.ctlok.com/company">
         <employeeInfo>
            <eid>E1000000</eid>
            <firstName>Lawrence</firstName>
            <lastName>Cheung</lastName>
            <age>24</age>
            <title>CEO</title>
         </employeeInfo>
         <employeeInfo>
            <eid>E1524125</eid>
            <firstName>Tom</firstName>
            <lastName>Wong</lastName>
            <age>22</age>
            <title>Clerk</title>
         </employeeInfo>
      </EmployeeInfoList>
   </soapenv:Body>
</soapenv:Envelope>

有時間再講解一下 Java Web Service Client 如何設定。

相閞書籍:

舊模板加了太多東西，令頁面載入的時間比較長。今次換了一個比較簡潔的模板，看上去的感覺比較舒服一點，再加上停用一些載入時間較長的 Fancy box，Sexy Bookmark 等等，並使用新的方法去載入 Syntax Highlighter， 希望令載入時間更加快。


更新 Log:

1. Add popular posts widget
2. Update jQuery to 1.6.1
3. Update Syntax Highlighter
4. Update Facebook javascript API
5. Update Facebook Like box (iframe -> XFBML)
6. Update Facebook Like box style
7. Update Facebook Like (iframe -> XFBML)
8. Update Google Adsense style
9. Update Google Adsense custom search
10. Remove Fancy Box
11. Remove BloggerAds banner

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