DWR通过Annotation与spring整合

 

      DWR 2.0 增加了一个很有趣的新特性，Annotation，因此可以摆脱了dwr.xml里面的配置.同时也可以方便的和spring整合.

  从官方网站下载dwr.jar包。然后将它放在你webapp的WEB-INF/lib目录下。 修改web.xml

 

  
< servlet > 
         < servlet-name > dwr-invoker </ servlet-name > 
         < servlet-class > 
            org.directwebremoting.servlet.DwrServlet
         </ servlet-class > 
         < init-param > 
             < param-name > debug </ param-name > 
             < param-value > true </ param-value > 
         </ init-param > 
         < init-param > 
             < param-name > logLevel </ param-name > 
             < param-value > DEBUG </ param-value > 
         </ init-param > 
         < init-param > 
             < param-name > classes </ param-name > 
             < param-value > 
       com.spring.User,com.beans.Book
             </ param-value > 
         </ init-param > 
     </ servlet > 
 
     < servlet-mapping > 
         < servlet-name > dwr-invoker </ servlet-name > 
         < url-pattern > /dwr/* </ url-pattern > 
     </ servlet-mapping > 
 
     < context-param > 
         < param-name > contextConfigLocation </ param-name > 
         < param-value > 
            /WEB-INF/beans.xml
         </ param-value > 
     </ context-param > 
     < listener > 
         < listener-class > 
            org.springframework.web.context.ContextLoaderListener
         </ listener-class > 
     </ listener >
 

       beans.xml是spring的配置文件.org.springframework.web.context.ContextLoaderListener是一个监听器.

<  init-param  >  
              <  param-name  >  classes  </  param-name  >  
              <  param-value  >  
       com.spring.User,com.beans.Book
              </  param-value  >  
          </  init-param  >  

param-value:参数为被注解的类. 

编写相关类          
  com.beans.Book:

@DataTransferObject(converter=BeanConverter.class)
public   class  Book {
    @RemoteProperty
     private  String name;
    @RemoteProperty
     private  String author;

     public  String getAuthor() {
         return  author;
    }

     public   void  setAuthor(String author) {
         this .author  =  author;
    }

     public  String getName() {
         return  name;
    }

     public   void  setName(String name) {
         this .name  =  name;
    }
}
        @DataTransferObject: 标注在客户端和服务器之间转换类.对应dwr.xml中的<convert>标签.
               注解的源代码:
                     

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface DataTransferObject
{
    /**
     * Converter that converts instance of the class (default: bean converter).
     */
    Class<? extends Converter> converter() default BeanConverter.class;

    /**
     * Parameters for the converter.
     */
    Param[] params() default {};
}
         关于annotation可以看这篇文章,java元数据
        @RemoteProperty :标注在类中需要转换的属性.
            源代码:
                  

@Target({ ElementType.FIELD, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface RemoteProperty
{
}

       如果使用dwr.xml配置,可以这样:
      

<convert converter="bean" match="com.beans.Book">
  <param name="include" value="name, author"/>
</convert>

 User:

@RemoteProxy(name="user",creator=SpringCreator.class,
        creatorParams={
            @Param(name="beanName",value="user")
            })
@DataTransferObject(converter=BeanConverter.class)
public class User {
    @RemoteProperty 
    private String welcome;
    @RemoteProperty 
    private String username;
    @RemoteProperty 
    private String address;
    @RemoteProperty 
    private List<Book> books;
    @RemoteProperty
    private int age;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
    @RemoteMethod
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getWelcome() {
        return welcome;
    }

    public void setWelcome(String welcome) {
        this.welcome = welcome;
    }
    @RemoteMethod
    public List<Book> getBooks() {
        return books;
    }
    
    public void setBooks(List<Book> books) {
        this.books = books;
    }
    @RemoteMethod
    public User getUser(String welcome) {
        this.welcome = welcome;
        return this;
    }

}

      @RemoteProxy:标注要给远程调用的类.
               RemoteProxy的name设置创造出来的对象的名字,creator指定使用那种创造器,例子中使用SpringCreator.creatorParams指定创造器的其他参数.不同的创造器参数是不同的.
      @RemoteMethod:标注给远程调用的方法

4.修改beans.xml
      

<bean id="remote" class="com.spring.Remote"></bean>
    <bean id="user" class="com.spring.User" 
            p:username="windfree" p:address="anhui hefei" p:age="25">
        <property name="books">
            <list>
                <ref bean="C"/>
               <ref bean="java"/>
            </list>
        </property>
    </bean>
    <bean id="java" class="com.beans.Book" p:name="java" p:author="mypure"></bean>
    <bean id="C" class="com.beans.Book" p:name="C" p:author="zgliu"></bean>
   其中p为spring2.0中提供的标签.
5.html页面
      

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <title>SpringUserInfo.html</title>
        <script type='text/javascript' src='/DWRExample/dwr/interface/user.js'></script>
        <script type='text/javascript' src='/DWRExample/dwr/engine.js'></script>
        <script type='text/javascript' src='/DWRExample/dwr/util.js'></script>
        <script type="text/javascript">
        function test(){
            user.getUser("Hello",callback);   
        }
        var cellFuncs = [
              function(data) { return data.name; },
              function(data) { return data.author; },
            ];
        function callback(user){
            //alert(user.books)
             DWRUtil.setValue('result',"欢迎你！"+"   姓名："+user.username+",年龄："+user.age+"，住址："+user.address);   
             DWRUtil.addRows('tableInfo',user.books,cellFuncs,
                     { escapeHtml:false ,
                   rowCreator:function(options) {
                        var row = document.createElement("tr");
                        var index = options.rowIndex * 50;
                        row.style.color = "rgb(" + index + ",0,0)";
                        return row;
                      },
                  cellCreator:function(options) {
                    var td = document.createElement("td");
                    var index = 255 - (options.rowIndex * 50);
                    td.style.backgroundColor = "rgb(" + index + ",255,255)";
                    td.style.fontWeight = "bold";
                    return td;
                  }
             })
        }
    </script>

    </head>

    <body>
              
        <input id="jbutton" type="button" value="取得信息" onclick="test()" />
        <br>
        <div id="result"></div><br>
        <table border="1">
            <thead><tr>
                <th>书名</th><th>姓名</th>                
            </tr></thead>
            <tbody id="tableInfo">
            </tbody>
        </table>
    </body>
</html>

      其中使用了util.js中的一些函数.