自己写struts2分页标签

来源：互联网发布：上海驿友微盒软件编辑：程序博客网时间：2024/05/01 05:28

想自己做标签的朋友可以来看一下.

这几天一直在研究Web分页,可能有的朋友会觉得这很简单,我想说的是,把任何简单的事做好就是不简单.我也正在努力着.

因为在用struts2写一个东西,分页用得比较频繁,所以决定自己写一个分页标签,编入自己的类库,准备一用它很多年,拷贝好带身边:)

这里把源码跟大家分享,希望对某些朋友有用.其实我一直觉得标签和.net里服务器控件是一回事.struts2的高扩展性为我们自己实现标签提供了很大的便捷.OK,进入主题

实现自定义struts2标签分三个部分:

1.定义标签在这步要创建标签说明文件 *.tld

2.实现标签组件这里只需继承struts2中的组件类和标签类就行了

3.用freemarker渲染标签这步要创建一个*.ftl文件.同时我把相关分页逻辑也写在了这里

这个标签是用在struts2环境里的,所以需要你的项目需要引入struts2的常用包.这里就不多说了.

下面是效果图

下面是源代码:

在/web-inf下建立tlds文件夹,在其中新建iThink.tld文件(名字随个人喜好),内容如下:

Code:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
<tlib-version>2.2.3</tlib-version>
<jsp-version>1.2</jsp-version>
<short-name>ithink</short-name>
<uri>/ithink-tags</uri>
<display-name>"iThink Tags"</display-name>
<description><![CDATA["iThink is a student team. iThink Tags supports custom components that usually used in web develop"]]></description>
<tag>
<name>pager</name>
<tag-class>org.icim.pager.struts2.PagerTag</tag-class>
<body-content>JSP</body-content>
<attribute>
<name>totalRecord</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[总记录数]]></description>
</attribute>
<attribute>
<name>totalPage</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[总页数]]></description>
</attribute>
<attribute>
<name>curPage</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[当前页号]]></description>
</attribute>
<attribute>
<name>pageLimit</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[每版最多显示的页数,最好为奇数]]></description>
</attribute>
<attribute>
<name>url</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[翻页时的请求地址,如:list?page={page},其中的{page}会被动态地替换]]></description>
</attribute>
<attribute>
<name>curCssClass</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[当前页的span标签的cssClass]]></description>
</attribute>
<attribute>
<name>showTotalPage</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[是否显示总页数,默认为"true"]]></description>
</attribute>
<attribute>
<name>showTotalRecord</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[是否显示总记录数,只有设置了总记录数属性的时候才有效,默认为"false"]]></description>
</attribute>
<attribute>
<name>directJumpType</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description><![CDATA[直接跳转的方式,"goto"或"select",默认为none]]></description>
</attribute>
<attribute>
<name>accesskey</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html accesskey attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>cssClass</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The css class to use for element]]></description>
</attribute>
<attribute>
<name>cssStyle</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The css style definitions for element to use]]></description>
</attribute>
<attribute>
<name>disabled</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html disabled attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>id</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[id for referencing element. For UI and form tags it will be used as HTML id attribute]]></description>
</attribute>
<attribute>
<name>key</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the key (name, value, label) for this particular component]]></description>
</attribute>
<attribute>
<name>label</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Label expression used for rendering a element specific label]]></description>
</attribute>
<attribute>
<name>labelposition</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Define label position of form element (top/left)]]></description>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The name to set for element]]></description>
</attribute>
<attribute>
<name>onblur</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[ Set the html onblur attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onchange</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onchange attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onclick</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onclick attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>ondblclick</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html ondblclick attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onfocus</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onfocus attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onkeydown</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onkeydown attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onkeypress</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onkeypress attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onkeyup</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onkeyup attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onmousedown</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onmousedown attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onmousemove</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onmousemove attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onmouseout</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onmouseout attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onmouseover</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onmouseover attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onmouseup</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onmouseup attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>onselect</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html onselect attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>required</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[If set to true, the rendered element will indicate that input is required]]></description>
</attribute>
<attribute>
<name>requiredposition</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Define required position of required form element (left|right)]]></description>
</attribute>
<attribute>
<name>tabindex</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html tabindex attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>template</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The template (other than default) to use for rendering the element]]></description>
</attribute>
<attribute>
<name>templateDir</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The template directory.]]></description>
</attribute>
<attribute>
<name>theme</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[The theme (other than default) to use for rendering the element]]></description>
</attribute>
<attribute>
<name>title</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the html title attribute on rendered html element]]></description>
</attribute>
<attribute>
<name>tooltip</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the tooltip of this particular component]]></description>
</attribute>
<attribute>
<name>tooltipConfig</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Set the tooltip configuration]]></description>
</attribute>
<attribute>
<name>value</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
<description><![CDATA[Preset the value of input element.]]></description>
</attribute>
</tag>
<tag>
<name>textfield</name>
<tag-class>org.apache.struts2.views.jsp.ui.TextFieldTag</tag-class>
<body-content>JSP</body-content>
<description><![CDATA[Render an HTML input field of type text]]></description>
</tag>
</taglib>

原UIBean通用的属性我是直接从struts2源代码包里面copy来的.支持属性非常丰富.呵呵

建立组件类和标签类:

Pager.java:

Code:

/***********************************************************************
*
* Pager.java
*
* @creator Bruce Tsai
* @create-time Jun 12, 2009 10:53:38 PM
***********************************************************************/
package org.icim.pager.struts2;
import org.apache.struts2.components.UIBean;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;
import com.opensymphony.xwork2.util.ValueStack;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* struts2版的分页标签
*
*/
@StrutsTag(name = "pager", tldTagClass = "org.icim.pager.struts2.PagerTag", description = "struts2 pager by ithink")
public class Pager extends UIBean {
final public static String TEMPLATE = "pager";
protected String totalRecord;
protected String totalPage;
protected String curPage;
protected String pageLimit;
protected String url;
protected String curCssClass;
protected String showTotalPage;
protected String showTotalRecord;
protected String directJumpType;
public Pager(ValueStack stack, HttpServletRequest request,
HttpServletResponse response) {
super(stack, request, response);
}
/**
* 用于返回模板的名字，Struts2会自动在后面加入.ftl扩展名以找到特定的模板文件。
*/
@Override
protected String getDefaultTemplate() {
return TEMPLATE;
}
/**
* 设置UIBean的属性，一般Tag中有几个这样的属性，这里就有几个 StrutsTagAttribute注解，说明该属性是int类型，这一步很重要
*
* @param totalPage
*/
@StrutsTagAttribute(description = "total records", type = "Long")
public void setTotalRecord(String totalRecord) {
this.totalRecord = totalRecord;
}
@StrutsTagAttribute(description = "total pages", type = "Integer")
public void setTotalPage(String totalPage) {
this.totalPage = totalPage;
}
@StrutsTagAttribute(description = "current page", type = "Integer")
public void setCurPage(String curPage) {
this.curPage = curPage;
}
@StrutsTagAttribute(description = "how many pages in a panel once", type = "Integer")
public void setPageLimit(String pageLimit) {
this.pageLimit = pageLimit;
}
@StrutsTagAttribute(description = "url to be linked", type = "String")
public void setUrl(String url) {
this.url = url;
}
@StrutsTagAttribute(description = "css style of current page", type = "String")
public void setCurCssClass(String curCssClass) {
this.curCssClass = curCssClass;
}
@StrutsTagAttribute(description = "whether to show totalPage", type = "Boolean", defaultValue = "true")
public void setShowTotalPage(String showTotalPage) {
this.showTotalPage = showTotalPage;
}
@StrutsTagAttribute(description = "whether to show currentPage", type = "Boolean", defaultValue = "false")
public void setShowTotalRecord(String showTotalRecord) {
this.showTotalRecord = showTotalRecord;
}
// TODO 直接页面跳转
// 这里的directJumpType默认值为none，可选值为 'select', 'goto'
@StrutsTagAttribute(description = "show type of direct jump type. such as select,textbox which can lead going to a page directly", type = "String", defaultValue = "none")
public void setDirectJumpType(String directJumpType) {
this.directJumpType = directJumpType;
}
/**
* 重写evaluateExtraParams（）方法，在UIBean初始化后会调用这个方法来初始化设定参数，如addParameter方法，会在freemarker里的parameters里加入一个key
* value。这里要注意findString，还有相关的findxxxx方法，它们是已经封装好了的解释ognl语法的工具，具体是怎么样的，大家可以查看一下UIBean的api
* doc
*/
@Override
protected void evaluateExtraParams() {
super.evaluateExtraParams();
// findValue()方法本身已对OGNL进行了处理
if (totalRecord != null) {
addParameter("totalRecord", findValue(totalRecord));
}
if (totalPage != null) {
addParameter("totalPage", findValue(totalPage));
}
if (curPage != null) {
addParameter("curPage", findValue(curPage));
}
if (pageLimit != null) {
addParameter("pageLimit", findValue(pageLimit));
}
if (url != null) {
addParameter("url", findValue(url, String.class));
}
if (curCssClass != null) {
addParameter("curCssClass", findValue(curCssClass,String.class));
}
if (showTotalPage != null) {
addParameter("showTotalPage", findValue(showTotalPage,
Boolean.class));
}
if (showTotalRecord != null) {
addParameter("showTotalRecord", findValue(showTotalRecord,Boolean.class));
}
if (directJumpType != null) {
addParameter("directJumpType", findValue(directJumpType));
}
}
}

PagerTag.java:

Code:

/***********************************************************************
*
* PagerTag.java
*
* @creator Bruce Tsai
* @create-time Jun 13, 2009 12:08:53 AM
***********************************************************************/
package org.icim.pager.struts2;
import org.apache.struts2.views.jsp.ui.AbstractUITag;
import org.apache.struts2.components.Component;
import com.opensymphony.xwork2.util.ValueStack;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* struts2 版分页标签
*/
public class PagerTag extends AbstractUITag {
private static final long serialVersionUID = 719669934024053141L;
protected String totalRecord;
protected String totalPage;
protected String curPage;
protected String pageLimit;
protected String url;
protected String curCssClass;
protected String showTotalPage;
protected String showTotalRecord;
protected String directJumpType;
protected void populateParams() {
super.populateParams();
Pager pager = (Pager) component;
pager.setTotalRecord(totalRecord);
pager.setTotalPage(totalPage);
pager.setCurPage(curPage);
pager.setPageLimit(pageLimit);
pager.setUrl(url);
pager.setCurCssClass(curCssClass);
pager.setShowTotalPage(showTotalPage);
pager.setShowTotalRecord(showTotalRecord);
pager.setDirectJumpType(directJumpType);
}
@Override
public Component getBean(ValueStack stack, HttpServletRequest request,
HttpServletResponse response) {
return new Pager(stack, request, response);
}
public void setTotalRecord(String totalRecord){
this.totalRecord = totalRecord;
}
public void setTotalPage(String totalPage) {
this.totalPage = totalPage;
}
public void setCurPage(String curPage) {
this.curPage = curPage;
}
public void setPageLimit(String pageLimit) {
this.pageLimit = pageLimit;
}
public void setUrl(String url) {
this.url = url;
}
public void setCurCssClass(String curCssClass) {
this.curCssClass = curCssClass;
}
public void setShowTotalPage(String showTotalPage) {
this.showTotalPage = showTotalPage;
}
public void setShowTotalRecord(String showTotalRecord) {
this.showTotalRecord = showTotalRecord;
}
public void setDirectJumpType(String directJumpType) {
this.directJumpType = directJumpType;
}
}

在类文件根目录下(在myeclipse中是在src目录下,发布后会copy到web-inf/classes/ 里)建立template/simple/ 目录,里面创建pager.ftl文件,内容如下:

Code:

<#--显示总记录数,只有同时设置了总记录数和显示总记录数时才有效-->
<#if (parameters.totalRecord?exists) && (parameters.showTotalRecord?exists) && (parameters.showTotalRecord == true)>
${parameters.totalRecord}<#rt/>
</#if>
<#--打印选择页的面板 -->
<#--首先,当parameters.pageLimit为空时将其设定为total-->
<#if (parameters.pageLimit?exists)>
<#assign limit = parameters.pageLimit />
<#else>
<#assign limit = parameters.totalPage />
</#if>
<@pagePanel cur=parameters.curPage total=parameters.totalPage url=parameters.url limitlimit=limit />
<#--打印选择页的面板结束-->
<#--显示总页数-->
<#if parameters.showTotalPage?exists && (parameters.showTotalPage == true)>
..${parameters.totalPage}<#rt/>
</#if>
<#--打印翻页面板的宏,配合printPage,printButton-->
<#macro pagePanel cur total limit url curCssClass = "cur_page"><#--curCssClass默认值为cur_page-->
<#--limit的中间数-->
<#assign l_mid = (limit/2)?int + 1 />
<#--total的中间数-->
<#assign t_mid = (total/2)?int />
<#--情况一：总页数小于等于限制显示页数，这时显示所有页-->
<#if total <= limit>
<@printButton direct="left" valuable = false />
<@printPage left = 1 right = total curcur = cur urlurl = url curCssClasscurCssClass = curCssClass />
<@printButton direct="right" valuable = false />
<#else>
<#--情况二：总页数大于限制显示页数，这时又分三种情况-->
<#--情况1:显示的limit个页号在total个页面中偏向左端,1作为最左边的页号,当前页没能显示在中间,偏左,例:
total = 20,cur = 2,limit = 5.显示的页面为:1 [2] 3 4 5
这种情况 cur <= l_mid
-->
<#if cur <= l_mid>
<@printButton direct="left" valuable = false />
<@printPage left = 1 right = limit curcur = cur urlurl = url curCssClasscurCssClass = curCssClass />
<@printButton direct="right" valuable = true />
<#--情况2:显示的limit个页号在total个页面中偏向右端,total作为最右边的页号,当前页没能显示在中间,偏右,例:
total = 20,cur = 19,limit = 5.显示的页面为:16 17 18 [19] 20
这种情况 cur > total - l_mid
-->
<#elseif (cur > (total - l_mid))>
<@printButton direct="left" valuable = true />
<@printPage left = (total - limit + 1) right = total curcur = cur urlurl = url curCssClasscurCssClass = curCssClass />
<@printButton direct="right" valuable = false />
<#--在中间的情况-->
<#else>
<@printButton direct="left" valuable = true />
<@printPage left = (cur - l_mid + 1) right = (cur + l_mid -1) curcur = cur urlurl = url curCssClasscurCssClass = curCssClass />
<@printButton direct="right" valuable = true />
</#if>
</#if>
</#macro>
<#--根据最左与最右的页号来打印所显示的页面，当前页为的cssStyle为curCssClass-->
<#macro printPage left right cur url curCssClass>
<#list left..right as p>
<#if p == cur>
${p}<#rt/>
<#else>
<a href = "<@makeURL text=url page=p />">${p}</a><#rt/>
</#if>
</#list>
</#macro>
<#--翻页控制按钮,direct选择"left"或"right",avaluable设置是否有链接-->
<#macro printButton direct valuable = true>
<#if direct == "left">
<#if valuable>
<a href="<@makeURL text=parameters.url page=1 />"> << </a><#rt/>
<a href="<@makeURL text=parameters.url page=parameters.curPage-1 />"> < </a><#rt/>
<#else>
<<<#rt/>
<<#rt/>
</#if>
<#else>
<#if valuable>
<a href="<@makeURL text=parameters.url page=parameters.curPage+1 />"> > </a><#rt/>
<a href="<@makeURL text=parameters.url page=parameters.totalPage />"> >> </a><#rt/>
<#else>
><#rt/>
>><#rt/>
</#if>
</#if>
</#macro>
<#--产生动态URL的宏-->
<#macro makeURL text page>
<#if text?last_index_of("{page}") < 0>
${text}?page=${page}
<#else>
${text?replace("{page}",page)}
</#if>
</#macro>

感觉freemarker用起来挺方便的,我花了一个上午粗略地学了一下.有兴趣可以看这篇笔记:FreeMarker详解:http://student.csdn.net/space.php?uid=46942&do=blog&id=4769

最后,需要在你的struts.xml配置文件里做如下设置

Code:

<constant name="struts.ui.theme" value="simple" />

也就是对应之前建立的theme/simple目录

好了,标签部分就做完了.下面就是使用标签.建立test.jsp

Code:

<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%@ taglib prefix="ithink" uri="/ithink-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>pager tag test</title>
</head>
<body>
<div class="pagination">
<ithink:pager curPage="3" totalPage="88"
url="listPaper.action?pno={page}" pageLimit="9" showTotalPage="true"
totalRecord="1988" showTotalRecord="true" />
</div>
</body>
</html>

还需要为它设置CSS样式:

Code:

/*---------------------pagination-----------------------------*/
div.pagination {
padding:5px;
margin:5px;
text-align:center;
float:left;
font-size:12px;
}
div.pagination a {
padding: 2px 5px 2px 5px;
margin-right: 2px;
border: 1px solid #ddd;
text-decoration: none;
color: #d8325d;
}
div.pagination a:hover, div.pagination a:active {
border:1px solid #ddd;
color: #fff;
background-color: #d8325d;
}
div.pagination span.cur_page {
padding: 2px 5px 2px 5px;
margin-right: 2px;
border: 1px solid #ddd;
font-weight: bold;
background-color: #d8325d;
color: #FFF;
}
div.pagination span {
padding: 2px 5px 2px 5px;
margin-right: 2px;
border: 1px solid #ddd;
text-decoration: none;
color: #d8325d;
}

到此一切都OVER了.如果你觉得我的实现不能满足要求,完全可以自己再写一个pager.ftl.比如说显示:第一页上一页下一页最后一页,只要在使用标签时指定theme属性,比如说"text",然后再在theme/text目录下重新写一个pager.ftl就行了

其中directJump属性所指的值还没有实现,希望有兴趣的朋友能一起完善它.