Struts2分页-自定义标签-类似百度分页

最新推荐文章于 2019-10-20 18:42:07 发布

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#Struts2自定义标签实现类似百度分页

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本文介绍如何在Eclipse环境下使用Struts2框架自定义分页标签，包括配置web.xml、创建自定义tld文件、实现PageTag类及Pages逻辑类等内容，并提供了具体的代码示例。

备份一下，以后继续学习

1.类似百度的数字分页

我做的例子是Eclipse环境下的

这是我的结构图:

以下是代码:

1 . web.xml

<?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" id="WebApp_ID" version="2.5">
  
  <filter>
		<filter-name>struts2</filter-name>
		<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	<jsp-config>
		<taglib>
			<taglib-uri>/WEB-INF/struts-tags.tld</taglib-uri>
			<taglib-location>/WEB-INF/struts-tags.tld</taglib-location>
		</taglib>
	</jsp-config>
	
  
</web-app>

我自定义的tld文件

2 . wangs.tld

<?xml version="1.0" encoding="UTF-8"?>
<!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>wangs</short-name>
	<uri>/wangs</uri>
        <tag>
            <name>pages</name>
            <tag-class>com.wangs.tag.PageTag</tag-class>
            <body-content>empty</body-content>
            <attribute>
                <name>cpage</name>
                <required>true</required>
                <rtexprvalue>true</rtexprvalue>
            </attribute>
            <attribute>
                <name>total</name>
                <required>true</required>
                <rtexprvalue>true</rtexprvalue>
            </attribute>
            <attribute>
                <name>visitUrl</name>
                <required>true</required>
                <rtexprvalue>true</rtexprvalue>
            </attribute>
            <attribute>
                <name>styleClass</name>
                <required>false</required>
                <rtexprvalue>true</rtexprvalue>
            </attribute>
            <attribute>
                <name>theme</name>
                <required>false</required>
                <rtexprvalue>true</rtexprvalue>
            </attribute>
        </tag>
</taglib>

3 . struts-tags.tld 从struts2-core-2.1.8.1.jar 中复制

4 . struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
	"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
	"http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
	<package name="TagDemo" namespace="/" extends="struts-default">	
		<action name="list"
			class="action.DemoAction" method="execute">
			<result name="success">/list.jsp</result>
		</action>
	</package>
</struts>

5 . PageTag.java Bean

package com.wangs.tag;

import com.opensymphony.xwork2.util.ValueStack;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.components.Component;
import org.apache.struts2.views.jsp.ComponentTagSupport;

/**
 * 分页标签
 */
public class PageTag extends ComponentTagSupport {

	private String cpage;
	private String total;
	private String visitUrl;
	private String styleClass;
	private String theme;

	public void setCpage(String cpage) {
		this.cpage = cpage;
	}

	public void setTotal(String total) {
		this.total = total;
	}

	public void setVisitUrl(String visitUrl) {
		this.visitUrl = visitUrl;
	}

	public void setStyleClass(String styleClass) {
		this.styleClass = styleClass;
	}

	public void setTheme(String theme) {
		this.theme = theme;
	}

	@Override
	public Component getBean(ValueStack arg0, HttpServletRequest arg1,
			HttpServletResponse arg2) {
		return new Pages(arg0, arg1);
	}

	protected void populateParams() {
		super.populateParams();

		Pages pages = (Pages) component;
		pages.setCpage(cpage);
		pages.setTotal(total);
		pages.setVisitUrl(visitUrl);
		pages.setStyleClass(styleClass);
		pages.setTheme(theme);

	}
}

6 . Pages.java 逻辑类

package com.wangs.tag;

import com.opensymphony.xwork2.util.ValueStack;
import java.io.IOException;
import java.io.Writer;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.components.Component;

/**
 * 分页逻辑
 */
public class Pages extends Component {

	private HttpServletRequest request;
	private String cpage;
	private String total;
	private String visitUrl;
	private String styleClass;
	private String theme;
	
	public String getCpage() {
		return cpage;
	}

	public void setCpage(String cpage) {
		this.cpage = cpage;
	}

	public String getTotal() {
		return total;
	}

	public void setTotal(String total) {
		this.total = total;
	}

	public String getVisitUrl() {
		return visitUrl;
	}

	public void setVisitUrl(String visitUrl) {
		this.visitUrl = visitUrl;
	}

	public String getStyleClass() {
		return styleClass;
	}

	public void setStyleClass(String styleClass) {
		this.styleClass = styleClass;
	}

	public String getTheme() {
		return theme;
	}

	public void setTheme(String theme) {
		this.theme = theme;
	}

	public Pages(ValueStack arg0, HttpServletRequest request) {
		super(arg0);
		this.request = request;
	}

	@Override
	public boolean start(Writer writer) {
		boolean result = super.start(writer);
		try {
			StringBuilder str = new StringBuilder();
			boolean isValid = true;

			// 从ValueStack中取出数值
			if (isValid) {
				if (total.startsWith("%{") && total.endsWith("}")) {
					total = total.substring(2, total.length() - 1);
					total = (String) this.getStack().findValue(total);
					isValid = total == null ? false : true;
				} else {
					isValid = false;
				}
			}
			if (isValid) {
				if (cpage.startsWith("%{") && cpage.endsWith("}")) {
					cpage = cpage.substring(2, cpage.length() - 1);
					cpage = (String) this.getStack().findValue(cpage);
					isValid = cpage == null ? false : true;
				} else {
					isValid = false;
				}
			}
			if (isValid) {
				if (visitUrl.startsWith("%{") && visitUrl.endsWith("}")) {
					visitUrl = visitUrl.substring(2, visitUrl.length() - 1);
					visitUrl = (String) this.getStack().findValue(visitUrl);
					isValid = visitUrl == null ? false : true;
				} else {
					isValid = false;
				}
			}

			if (isValid) {
				Integer cpageInt = Integer.valueOf(cpage);
				str.append("<span ");
				if (styleClass != null) {
					str.append(" class='" + styleClass + "'>");
				} else {
					str.append(">");
				}

				// 文本样式
				if (theme == null || "text".equals(theme)) {
					// 当前页与总页数相等
					if (cpage.equals(total)) {
						// 如果total = 1，则无需分页，显示“[第1页] [共1页]”
						if ("1".equals(total)) {
							str.append("[第 " + cpage + " 页]");
							str.append("&nbsp;[共 " + total + " 页]");
						} else {
							// 到达最后一页,显示“[首页] [上一页] [末页]”
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=1&total=" + total + "&visitUrl="
									+ visitUrl);
							str.append("'>[首页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt - 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>[上一页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + total + "&total=" + total
									+ "&visitUrl=" + visitUrl);
							str.append("'>[末页]</a>");
						}
					} else {
						// 当前页与总页数不相同
						if ("1".equals(cpage)) {
							// 第一页，显示“[首页] [下一页] [末页]”
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=1&total=" + total + "&visitUrl="
									+ visitUrl);
							str.append("'>[首页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt + 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>[下一页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + total + "&total=" + total
									+ "&visitUrl=" + visitUrl);
							str.append("'>[末页]</a>");
						} else {
							// 不是第一页，显示“[首页] [上一页] [下一页] [末页]”
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=1&total=" + total + "&visitUrl="
									+ visitUrl);
							str.append("'>[首页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt - 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>[上一页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt + 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>[下一页]</a> <a href='");
							str.append(visitUrl);
							str.append("?cpage=" + total + "&total=" + total
									+ "&visitUrl=" + visitUrl);
							str.append("'>[末页]</a>");
						}
					}
				} else if ("number".equals(theme)) { // 数字样式 [1 2 3 4 5 6 7 8 9
														// 10 > >>]
					Integer totalInt = Integer.valueOf(total);

					// 如果只有一页，则无需分页
					str.append("[&nbsp;");
					if (totalInt == 1) {
						str.append("<strong>1</strong>&nbsp;");
					} else {
						// 计算一共分几组
						int group = (totalInt - 1) / 10 + 1;
						// 当前第几组
						int cgroup = (cpageInt - 1) / 10 + 1;

						if (cgroup > 1) {
							// 当前不是第一组，要显示“<< <”
							// <<：返回前一组第一页
							// <：返回前一页
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=" + ((cgroup - 2) * 10 + 1)
									+ "&total=" + total + "&visitUrl=" + visitUrl);
							str.append("'>&laquo;</a>&nbsp;");
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt - 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>&#8249;</a>&nbsp;");
						}
						// 10个为一组显示
						for (int i = (cgroup - 1) * 10 + 1; i <= totalInt
								&& i <= cgroup * 10; i++) {
							if (cpageInt == i) { // 当前页要加粗显示
								str.append("<strong>");
							}
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=" + i + "&total=" + total
									+ "&visitUrl=" + visitUrl);
							str.append("'>" + i + "</a>&nbsp;");
							if (cpageInt == i) {
								str.append("</strong>");
							}
						}
						// 如果多于1组并且不是最后一组，显示“> >>”
						if (group > 1 && cgroup != group) {
							// >>：返回下一组最后一页
							// >：返回下一页
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage=" + (cpageInt + 1) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>&#8250;</a>&nbsp;");
							str.append("<a href='");
							str.append(visitUrl);
							str.append("?cpage="
									+ ((cgroup * 10 + 10) > totalInt ? totalInt
											: (cgroup * 10 + 10)) + "&total="
									+ total + "&visitUrl=" + visitUrl);
							str.append("'>&raquo;</a>&nbsp;");
						}
					}
					str.append("]");
				}
				str.append("</span>");
			}

			writer.write(str.toString());

		} catch (IOException ex) {
			Logger.getLogger(Pages.class.getName()).log(Level.SEVERE, null, ex);
		}
		return result;
	}
}

7 . DemoAction.java

package action;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionSupport;

public class DemoAction extends ActionSupport {

	private static final long serialVersionUID = 2120921059932936210L;

	private String cpage;
	private String total;
	private String visitUrl;

	public String execute() {
		// 测试地址:
		// (1).当前页第一页,共5页
		// http://localhost:8080/TagDemo/list?cpage=1&total=5&visitUrl=list
		// (2).当前页第一页,共18页
		// http://localhost:8080/TagDemo/list?cpage=1&total=18&visitUrl=list
		return Action.SUCCESS;
	}

	public String getCpage() {
		return cpage;
	}

	public void setCpage(String cpage) {
		this.cpage = cpage;
	}

	public String getTotal() {
		return total;
	}

	public void setTotal(String total) {
		this.total = total;
	}

	public String getVisitUrl() {
		return visitUrl;
	}

	public void setVisitUrl(String visitUrl) {
		this.visitUrl = visitUrl;
	}

}

8 . 页面 list.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="wangs" uri="/WEB-INF/wangs.tld"%>
<%@ taglib prefix="s" uri="/WEB-INF/struts-tags.tld"%>

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <link href="css/style.css" rel="stylesheet" type="text/css"/>
        <title>List</title>
    </head>
    <body>
        共 <s:property value="total"/> 页 第 <s:property value="cpage"/> 页<br><br>
        <wangs:pages cpage="%{cpage}" total="%{total}" visitUrl="%{visitUrl}" styleClass="page" theme="text"/>
    </body>
</html>

theme 控制分页的形式：1.类似百度的数字分页 2.[ 首页下一页末页 ] 的文字分页

参考一: http://tangshuo.iteye.com/blog/189447

参考二: http://tangshuo.iteye.com/blog/189820