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Liferay7 BPM门户开发之17: Portlet 生命周期

Portlet 生命周期

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init() =〉 render() =〉 processAction() =〉 processEvent() =〉 serveResource() =〉destroy()

  • init()

    在Liferay容器部署portlet时,启动portlet实例化

    init有两个写法:

    •  public void init() throws PortletException
    •  public void init(PortletConfig config) throws PortletException

      PortletConfig对象用于读取portlet配置(定义在portlet.xml)

  • render()

    HTML的UI输出,是最常用到的方法了,一个例子

@Override public void render(RenderRequest request, RenderResponse response)   throws PortletException, IOException {  _log.info(" 做些你自己定义的事情");  super.render(request, response); }

    值得注意的是:

    • 在render()的一般最后一行,需要写这句:super.render(request,response),如果不写会不能正常工作,会造成GenericPortlet继承链的断裂(render() 在GenericPortlet中被重写);
    • Portlet不能直接访问ServletRequest和ServletResponse;
    • RenderRequest和RenderResponse是接口,继承于PortletRequest和PortletResponse;
    • 如果一个页面有多个Portlets,当每次页面刷新,所有Portlets实例的render()就会被全部调用一次;
    • 有趣的是,Portlet规范并没有一个排序的机制,去安排这些Portlets的render()顺序,这证明了Portlet的独立性,如果要定制开发时序的加载,那必须自己去实现一个GenericPortlet的子类,或者直接扩展MVCPortlet,增加一个加载队列。
  • processAction()

    action 处理,后面再详细介绍,这里只要知道ActionRequest也是一个接口继承

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  • processEvent()

    监听时间处理

  • serveResource()

    通过resource URL处理资源

  • destroy()

    portlet卸载时的处理

    

Portlet 容器负责的工作

  • 装载portlet类
  • 创建portlet实例
  • 初始化
  • 向portlet实例发送用户请求(request)
  • 销毁实例(当容器卸载portlet)

Portlet和Servlet的区别

见:

Liferay7 BPM门户开发之15: Liferay开发体系简介

 

Portlet类的层次

  • GenericPortlet实现了Portlet接口;
  • LiferayPortlet是GenericPortlet的子类,并且提供了一些额外方法;
  • MVCPortlet继承与LiferayPortlet.提供了用于MVC架构的一些方法;
  • UserCustomPortlet (用户定义portlet)继承与MVCPorrtlet;

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URLs 传递

  • Portlet在开发调试时不如servlet中那样方便直接,无法定义静态指定地址url,而是通过以下几种方式:
    •   Render URL:call render method,用于界面控制
    •   Action URL:call action method,用于服务调用
    •   Resource URL:call serve resource method,用于访问资源

 

Render 阶段

首先,介绍Render URL,有四种方式:

方式1、Portlet Tag (portlet:renderURL)

view.jsp

<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %>

<%@page import="com.liferay.portal.kernel.portlet.LiferayPortletMode"%>
<%@page import="com.liferay.portal.kernel.portlet.LiferayWindowState"%>

<portlet:renderURL var="renderUrl"  windowState="<%=LiferayWindowState.NORMAL.toString() %>" copyCurrentRenderParameters="true" portletMode="<%=LiferayPortletMode.VIEW.toString()%>"> <portlet:param name="param" value="XXXXXX"/></portlet:renderURL> <a href="${renderUrl}">RenderURL Created by Portlet Tag</a>
render()
private static final Log _log = LogFactoryUtil.getLog(YourPortlet.class.getName());  @Override public void render(RenderRequest request, RenderResponse response)   throws PortletException, IOException {  _log.info(" This is render method");  String data = request.getParameter("param");  String data1= ParamUtil.getString(request, "param","");  super.render(request, response); }

最终会实际产生以下URL:

http://localhost:8080/web/portletTest/test?

  • p_p_id=renderURLbyportletTag_WAR_renderURLbyportlet
  • &p_p_lifecycle=0
  • &p_p_state=normal
  • &p_p_mode=view
  • &p_p_col_id=column-1
  • &p_p_col_count=1
  • &_renderURLbyportletTag_WAR_renderURLbyportlet_param=XXXXXX

p_p_id 是portlet Id

p_p_lifecycle是生命周期的当前阶段,定义是:0 – render;1 – action;2 – serve resource;

p_p_col_id是多列布局中的当前页第几列;

p_p_col_count是当前页的布局总列数;

最后一个就是用户定自定url参数了,由jsp传递;

 

方式2、PortletURLFactoryUtil 方式

这种是服务端直接控制,jsp基本不用写什么逻辑,后台控比较喜欢用

render()

@Overridepublic void render(RenderRequest request, RenderResponse response)  throws PortletException, IOException {   _log.info(" This is render method of RenderURLByJavaAPIPortlet");   String data = request.getParameter("param");   String data1= ParamUtil.getString(request, "param","");      ThemeDisplay themeDisplay = (ThemeDisplay)request.getAttribute(WebKeys.THEME_DISPLAY);   PortletURL renderUrl =  PortletURLFactoryUtil.create(request, themeDisplay.getPortletDisplay().getId(), themeDisplay.getPlid(), PortletRequest.RENDER_PHASE);   renderUrl.setWindowState(LiferayWindowState.NORMAL);   renderUrl.setPortletMode(LiferayPortletMode.VIEW);   renderUrl.setParameter("param", "This parameter comes from Render URL generated with Java API");   request.setAttribute("renderUrlByJavaAPI", renderUrl.toString());     super.render(request, response); }

其中,plid 是page layout id

在jsp中,只用一行代码:

<a href="http://www.mamicode.com/${renderUrlByJavaAPI}">Render Url created by Java API</a>

还有一种灵活方式,即可以由jsp来直接输出

<%@ taglib uri="http://liferay.com/tld/theme" prefix="liferay-theme" %><liferay-theme:defineObjects/><% PortletURL renderUrlFromJSP = renderResponse.createRenderURL(); renderUrlFromJSP.setParameter("param1", "This portletULR is created with API in JSP"); renderUrlFromJSP.setWindowState(LiferayWindowState.NORMAL); renderUrlFromJSP.setPortletMode(LiferayPortletMode.VIEW); %><a href="<%=renderUrlFromJSP%>">Render Url created by JSP</a>

 

方式3:Liferay Tag (liferay-portlet:renderURL)

 view.jsp<%@ taglib uri="http://liferay.com/tld/portlet" prefix="liferay-portlet" %><liferay-portlet:renderURL var="openPortletURL" copyCurrentRenderParameters="true" portletMode="<%=LiferayPortletMode.VIEW.toString() %>"   windowState="<%=LiferayWindowState.NORMAL.toString()%>">  <liferay-portlet:param name="param" value="This is from Liferay TAG"/></liferay-portlet:renderURL> <a href="${openPortletURL}">Render Url created by Liferay TAG in JSP</a>

render() 同第一种写法(Portlet Tag方式)

方式4:JavaScript (by AUI)

view.jsp<%@page import="com.liferay.portal.kernel.portlet.LiferayWindowState"%><%@page import="com.liferay.portal.kernel.portlet.LiferayPortletMode"%><%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %><%@ taglib uri="http://liferay.com/tld/aui" prefix="aui" %><%@ taglib uri="http://liferay.com/tld/theme" prefix="liferay-theme" %> <liferay-theme:defineObjects/><portlet:defineObjects /> <a id="renderURLWithJS" href=""> This render URL link is created with Javascript</a> <aui:script>AUI().use(‘liferay-portlet-url‘, function(A) {var renderUrl1 = Liferay.PortletURL.createRenderURL();renderUrl1.setWindowState("<%=LiferayWindowState.NORMAL.toString() %>");renderUrl1.setParameter("param","This value comes from Javascript");renderUrl1.setPortletMode("<%=LiferayPortletMode.VIEW %>");renderUrl1.setPortletId("<%=themeDisplay.getPortletDisplay().getId() %>"); A.one("#renderURLWithJS").set(‘href‘,renderUrl1.toString());alert("renderUrl1 is ->"+renderUrl1.toString());alert(A.one("#renderURLWithJS").attr("href")); }); </aui:script> 这种比较不常用

render() 同第一种写法(Portlet Tag方式)

 

action 阶段

在涉及页面处理业务逻辑,或其他Portlet交互,或者Form提交Action时,就需要我们定义Action方法,actionURL 就是用来传递Action的id

它是和jsp一对一对应的,比如jsp中:

view.jsp<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %> <portlet:defineObjects />User Name is : <b> ${userName}</b><portlet:actionURL name="actionMethod1" var="sampleActionMethodURL"></portlet:actionURL> <form action="${sampleActionMethodURL}" method="post">    UserName :-<input type="text" name="userName"><br>    <input type="submit" value="Submit"> </form> <portlet:actionURL name="addName" var="addNameUrl"></portlet:actionURL> <a href="${addNameUrl}">Add Name</a>

前提还要定义portlet.xml

portlet.xml首先要定义<portlet-name>custom-liferaymvc</portlet-name><display-name>Custom Liferaymvc</display-name><portlet-class>com.companyname.portlet.CustomMVCPortlet</portlet-class><init-param>  <name>view-jsp</name>  <value>/jsp/view.jsp</value></init-param>

 

编写一个继承MVCPortlet的类

@ProcessAction(name="addName") public void addName(ActionRequest actionRequest,   ActionResponse actionResponse) throws IOException, PortletException, PortalException, SystemException{  actionRequest.setAttribute("userName", "Wangxin"); }@ProcessAction(name="actionMethod1")public void sampleActionMethod(ActionRequest request, ActionResponse response)                throws IOException, PortletException, PortalException, SystemException{            _log.info("This is sampleActionMethod ...");String userName = ParamUtil.get(actionRequest, "userName", StringPool.BLANK);  actionRequest.setAttribute("userName", userName);        }

 

如果跟踪一下,会是自动产生以下url:

http://localhost:8080/web/home?p_auth=e6cvA8tX
&p_p_id=testactionmethod_WAR_testactionmethodportlet
&p_p_lifecycle=1
&p_p_state=normal
&p_p_mode=view
&p_p_col_id=column-1
&_testactionmethod_WAR_testactionmethodportlet_javax.portlet.action=actionMethod1

 

另外PortletURLFactoryUtil 是一种后台产生action url的常用方式

java code:    @Override    public void render(RenderRequest request, RenderResponse response)            throws PortletException, IOException {                  ThemeDisplay themeDisplay = (ThemeDisplay)request.getAttribute(WebKeys.THEME_DISPLAY);          PortletURL actionUrl =  PortletURLFactoryUtil.create(request, themeDisplay.getPortletDisplay().getId(), themeDisplay.getPlid(), PortletRequest.ACTION_PHASE);          actionUrl.setWindowState(LiferayWindowState.NORMAL);          actionUrl.setPortletMode(LiferayPortletMode.VIEW);          actionUrl.setParameter("javax.portlet.action", "actionMethodByJavaApi");          actionUrl.setParameter("sampleParam", "This parameter comes from Action URL generated with Java API");          request.setAttribute("actionUrlByJavaAPI", actionUrl.toString());        super.render(request, response);    }     @ProcessAction(name="actionMethodByJavaApi")    public void actionMethodByJavaApi(ActionRequest request, ActionResponse response)            throws IOException, PortletException, PortalException, SystemException{        String sampleParam = ParamUtil.get(request, "sampleParam", "defaultValue");        _log.info("Sample Param is ::"+sampleParam);    } view.jsp<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %><portlet:defineObjects /><a href=http://www.mamicode.com/"${actionUrlByJavaAPI}">Action Url created by Java API in Portlet Class</a><br>

还有两种方式就不介绍了:
liferay-portlet:actionURL 和 JavaScript (AUI module – Liferay.PortletURL)

一个portlet交互的流程图

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resource 阶段

Render & action是最早被定义的规范,见portlet specification 1.0 (JSR-168).
resource serving 被定义于portlet specification 2.0 (JSR-286)
一句话概括serve resource做的事情:动态产生输出到客户端,负责向客户端发送动态内容
比如:下载文件,发送一个excle报表,发送xml、json文件......,这些在Render 周期是无法实现的

serve resource过程

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这里有比较好的介绍:
http://www.oracle.com/technetwork/java/jsr286-2-141964.html

Liferay7 BPM门户开发之17: Portlet 生命周期