JSP自定义分页标签TAG

淡淡的烟草味﹌ 2022-08-23 11:51 116阅读 0赞

首先我们需要在WEB-INF/tld/目录下创建page.tld文件

<?xml version="1.0" encoding="ISO-8859-1"?>
    <taglib>
    	<tlib-version>1.0</tlib-version>
    	<jsp-version>1.2</jsp-version>
    	<short-name>page</short-name>
    	<uri>http://www.kevin.com/taglibs/page</uri>
    	<tag>
    		<name>htmlPage</name>
    		<tag-class>com.lss.common.tag.PageTag</tag-class>
    		<body-content>JSP</body-content>
    		<description>htmlPage Tag</description>
    		<attribute>
    			<name>pageNo</name>
    			<required>false</required>
    			<rtexprvalue>true</rtexprvalue>
    		</attribute>
    		<attribute>
    			<name>pageSize</name>
    			<required>false</required>
    			<rtexprvalue>true</rtexprvalue>
    		</attribute>
    		<attribute>
    			<name>totalSum</name>
    			<required>true</required>
    			<rtexprvalue>true</rtexprvalue>
    		</attribute>
    		<attribute>
    			<name>url</name>
    			<required>true</required>
    			<rtexprvalue>true</rtexprvalue>
    		</attribute>
    		<attribute>
    			<name>showPage</name>
    			<required>false</required>
    			<rtexprvalue>true</rtexprvalue>
    		</attribute>
    	</tag>
    </taglib>

package com.lss.common.tag;
    
    import java.io.IOException;
    
    import javax.servlet.jsp.JspException;
    import javax.servlet.jsp.JspWriter;
    import javax.servlet.jsp.tagext.TagSupport;
    
    import com.lss.common.page.HtmlPage;
    import com.lss.common.page.Page;
    import com.lss.common.page.VariablePage;
    
    /**
     * 分页处理标签
     * 
     * @description
     * @DATE 2012-3-11下午09:08:46
     */
    public class PageTag extends TagSupport {
    	private int pageNo;
    	private int pageSize = 10;
    	private int totalSum;
    	private int showPage = 10;
    	private String url;
    
    	public int getPageNo() {
    		return pageNo;
    	}
    
    	public void setPageNo(int pageNo) {
    		this.pageNo = pageNo;
    	}
    
    	public int getPageSize() {
    		return pageSize;
    	}
    
    	public void setPageSize(int pageSize) {
    		this.pageSize = pageSize;
    	}
    
    	public int getTotalSum() {
    		return totalSum;
    	}
    
    	public void setTotalSum(int totalSum) {
    		this.totalSum = totalSum;
    	}
    
    	public int getShowPage() {
    		return showPage;
    	}
    
    	public void setShowPage(int showPage) {
    		this.showPage = showPage;
    	}
    
    	public String getUrl() {
    		return url;
    	}
    
    	public void setUrl(String url) {
    		this.url = url;
    	}
    
    	@Override
    	public int doEndTag() throws JspException {
    		if (pageSize == 0) {
    			return TagSupport.SKIP_PAGE;// 不显示分页
    		} else if (pageSize > totalSum) {
    			return TagSupport.SKIP_BODY;// 不显示分页
    		}
    		JspWriter out = pageContext.getOut();
    		try {
    			if (url.indexOf(";jsessionid=") == -1) {
    				if (url.indexOf("?") == -1) {
    					url += ";jsessionid=" + pageContext.getSession().getId() + "?pageNo=";
    				} else {
    					url = url.replaceFirst("\\?", ";jsessionid=" + pageContext.getSession().getId() + "?");
    					if (url.indexOf("pageNo=") == -1) {
    						url += "&pageNo=";
    					}
    				}
    			}
    			url = pageContext.getServletContext().getContextPath() + url;
    			VariablePage variablePage = new VariablePage(pageNo, totalSum, pageSize, url);
    			variablePage.setShowPageNum(showPage);
    			Page page = new HtmlPage(variablePage);
    			out.print(page.getFirstNo() + "  " + page.getBackpageNum() + "  " + page.pagination() + "  " + page.getNextpageNum() + "  " + page.getLastNo());
    		} catch (IOException ex) {
    			ex.printStackTrace();
    		}
    		return super.doEndTag();
    	}
    
    	@Override
    	public void release() {
    		url = null;
    		pageNo = 0;
    		totalSum = 0;
    		pageSize = 10;
    		super.release();
    	}
    
    	private static final long serialVersionUID = -2642907859641024483L;
    }

/**
     * HTML 分页类
     * 
     * @description
     * @DATE 2012-3-11下午10:33:14
     */
    public class HtmlPage extends Page {
    	public HtmlPage(VariablePage variablePage) {
    		super(variablePage);
    	}
    
    	public String pagination() {
    		String printNo = "";
    		// 如果已分页；并且页数小于等于要显示的页数
    		if (variablePage.totalPage > 1 && variablePage.totalPage <= variablePage.showPageNum) {
    			return displayAll();
    			// 如果分页数：大于显示的页码数
    		} else if (variablePage.totalPage > 1 && variablePage.totalPage > variablePage.showPageNum) {
    			if (variablePage.pageNo == 1) {// 当前页等于第一页
    				return fromFirstPagePrint();
    			} else if (variablePage.pageNo == variablePage.totalPage) {// 当前页等于最后一页
    				return fromLastPagePrint();
    			} else {// 如果当前页：即不是首页也不是尾页
    				if (variablePage.showPageNum % 2 == 0) {// 可以平分页码
    					int print$No = variablePage.showPageNum / 2;
    					if (variablePage.pageNo >= print$No) {
    						int index$No = variablePage.pageNo - print$No;
    						if (variablePage.pageNo + print$No >= variablePage.totalPage) {
    							return fromLastPagePrint();
    						} else {
    							if (index$No == 0)
    								index$No = 1;
    							for (int i = index$No; i < (variablePage.showPageNum + index$No); i++) {
    								if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL
    									printNo += (i + variablePage.split);
    								} else {
    									printNo += (buildA(variablePage, i) + variablePage.split);
    								}
    							}
    						}
    					} else {
    						return fromFirstPagePrint();
    					}
    				} else {// 打印页数不是偶数时：
    					int print$No = variablePage.showPageNum / 2 + 1;
    					if (variablePage.pageNo >= print$No && variablePage.pageNo + print$No < variablePage.totalPage) {
    						int index$No = variablePage.pageNo - print$No + 1;
    						for (int i = index$No; i < variablePage.showPageNum + index$No; i++) {
    							if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL
    								printNo += (i + variablePage.split);
    							} else {
    								printNo += (buildA(variablePage, i) + variablePage.split);
    							}
    						}
    					} else if (variablePage.pageNo <= print$No) {// 从第一页开始
    						return fromFirstPagePrint();
    					} else {
    						return fromLastPagePrint();
    					}
    				}
    			}
    			return (printNo);
    		} else {
    			return "1";
    		}
    	}
    
    	public String getBackpageNum() {
    		if (variablePage.pageNo <= 1) {
    			return buildSpan("上一页", variablePage);
    		} else {
    			return buildA("上一页", (variablePage.url + (variablePage.pageNo - 1)));
    		}
    	}
    
    	public String getNextpageNum() {
    		if (variablePage.pageNo >= variablePage.totalPage) {
    			return buildSpan("下一页", variablePage);
    		} else {
    			return buildA("下一页", variablePage.url + (variablePage.pageNo + 1));
    		}
    	}
    
    	public String buildSpan(String text, VariablePage variablePage) {
    		return "<span style=\"color:gray;\">" + text + "</span>";
    	}
    
    	public String buildA(String text, String url) {
    		return "<a href=\"" + url + "\">" + text + "</a>";
    	}
    
    	public String buildA(VariablePage variablePage, int num) {
    		return ("<a href=\"" + variablePage.url + num + "\">" + num + "</a>");
    	}
    }

public abstract class Page {
    	protected VariablePage variablePage;
    
    	public Page(VariablePage variablePage) {
    		this.variablePage = variablePage;
    		calculateTotalPage();
    	}
    
    	public int getStartIndex() {
    		return (getValidpageNum() - 1) * variablePage.pageSize;
    	}
    
    	public String getBackpageNum() {
    		if (variablePage.pageNo <= 1) {
    			return buildSpan("上一页", variablePage);
    		} else {
    			return buildA("上一页", variablePage.getUrl() + (variablePage.pageNo - 1));
    		}
    	}
    
    	public String getNextpageNum() {
    		if (variablePage.pageNo >= variablePage.totalPage) {
    			return buildSpan("下一页", variablePage);
    		} else {
    			return buildA("下一页", variablePage.getUrl() + (variablePage.pageNo + 1));
    		}
    	}
    
    	/**
    	 * 计算总页数
    	 */
    	private void calculateTotalPage() {
    		if (variablePage.totalSum % variablePage.pageSize == 0) {
    			variablePage.totalPage = variablePage.totalSum / variablePage.pageSize;
    		} else {
    			variablePage.totalPage = variablePage.totalSum / variablePage.pageSize + 1;
    		}
    		if (variablePage.totalPage < variablePage.pageNo) {
    			variablePage.pageNo = variablePage.totalPage;
    		} else if (variablePage.pageNo < 1) {
    			variablePage.pageNo = 1;
    		}
    	}
    
    	protected String displayAll() {
    		StringBuilder sBuilder = new StringBuilder(10);
    		sBuilder.append(variablePage.split);
    		for (int i = 1; i <= variablePage.totalPage; i++) {
    			if (i == variablePage.pageNo) {
    				sBuilder.append(i + variablePage.split);
    			} else {
    				sBuilder.append(buildA(variablePage, i) + variablePage.split);
    			}
    		}
    		return sBuilder.toString();
    	}
    
    	/**
    	 * 抽象出分页方法
    	 * 
    	 * @return
    	 */
    	public abstract String pagination();
    
    	/**
    	 * 实现从第一页开始打印
    	 * 
    	 * @return
    	 */
    	protected final String fromFirstPagePrint() {
    		StringBuffer buffer = new StringBuffer(100);
    		for (int i = 1; i <= variablePage.showPageNum; i++) {
    			if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL
    				buffer.append(i + variablePage.split);
    			} else {
    				buffer.append(buildA(variablePage, i) + variablePage.split);
    			}
    		}
    		return buffer.toString();
    	}
    
    	/**
    	 * 实现从最后一页开始打印
    	 * 
    	 * @return
    	 */
    	protected final String fromLastPagePrint() {
    		StringBuffer buffer = new StringBuffer(100);
    		int startPage = variablePage.totalPage - (variablePage.showPageNum - 1);
    		for (int i = startPage; i <= variablePage.totalPage; i++) {
    			if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL
    				buffer.append(i + variablePage.split);
    			} else {
    				buffer.append(buildA(variablePage, i) + variablePage.split);
    			}
    		}
    		return buffer.toString();
    	}
    
    	public String getFirstNo() {
    		if (isExistsPagination()) {
    			return buildA("首页", variablePage.url + 1);
    		} else {
    			return buildSpan("首页", variablePage);
    		}
    	}
    
    	/**
    	 * 判断是否存在分页
    	 * 
    	 * @return
    	 */
    	private boolean isExistsPagination() {
    		if (variablePage.totalSum > 1 && variablePage.totalPage > 1) {
    			return true;
    		}
    		return false;
    	}
    
    	public String getLastNo() {
    		if (isExistsPagination()) {
    			return buildA("尾页", variablePage.url + variablePage.totalPage);
    		} else {
    			return buildSpan("尾页", variablePage);
    		}
    	}
    
    	protected int getValidpageNum() {
    		if (variablePage.totalPage < variablePage.pageNo) {
    			return variablePage.pageNo = variablePage.totalPage;
    		} else if (variablePage.pageNo < 1) {
    			return variablePage.pageNo = 1;
    		} else {
    			return variablePage.pageNo;
    		}
    	}
    
    	public VariablePage getPageContant() {
    		return this.variablePage;
    	}
    
    	public abstract String buildSpan(String text, VariablePage variablePage);
    
    	public abstract String buildA(String text, String url);
    
    	public abstract String buildA(VariablePage variablePage, int num);
    	
    	public String printModifyPageSize(int pageSize){
    		StringBuilder builder=new StringBuilder(100);
    		builder.append("每页<input type='text' id='pageSize' style='width:20px' maxlength='2' name='pageSize'");
    		if(pageSize>0){
    			builder.append(" value='"+pageSize+"' ");
    		}
    		builder.append("/>条");
    		return builder.toString();
    	}
    }

/**
     * 分页基础变量
     * 
     * @description
     * @DATE 2012-3-11下午10:34:00
     */
    public class SimpleVariable {
    	/**
    	 * 显示页码
    	 */
    	protected int showPageNum = 10;
    	/**
    	 * 连接URL
    	 */
    	protected String url = null;
    	/**
    	 * 当前页码
    	 */
    	protected int pageNo = 1;
    	/**
    	 * 总页码
    	 */
    	protected int totalPage = 1;
    	/**
    	 * 总条数
    	 */
    	protected int totalSum = 0;
    	/**
    	 * 每页显示条数
    	 */
    	protected int pageSize = 10;
    
    	public String getUrl() {
    		return url;
    	}
    
    	public void setUrl(String url) {
    		this.url = url;
    	}
    
    	public int getTotalPage() {
    		return totalPage;
    	}
    
    	public void setTotalPage(int totalPage) {
    		this.totalPage = totalPage;
    	}
    
    	public int getTotalSum() {
    		return totalSum;
    	}
    
    	public void setTotalSum(int totalSum) {
    		this.totalSum = totalSum;
    	}
    
    	public int getPageSize() {
    		return pageSize;
    	}
    
    	public void setPageSize(int pageSize) {
    		this.pageSize = pageSize;
    	}
    
    	public int getShowPageNum() {
    		return showPageNum;
    	}
    
    	public void setShowPageNum(int showPageNum) {
    		this.showPageNum = showPageNum;
    	}
    
    	public int getPageNo() {
    		return pageNo;
    	}
    
    	public void setPageNo(int pageNo) {
    		this.pageNo = pageNo;
    	}
    }

/**
     * 分页变量
     * 
     * @description
     * @DATE 2012-3-11下午10:34:08
     */
    public class VariablePage extends SimpleVariable {
    	protected String split = "  ";
    	protected String style = "class='page'";
    
    	public VariablePage(int pageNo, int totalSum, int pageSize, String url) {
    		pageNo = pageNo < 1 ? 1 : pageNo;
    		super.pageNo = pageNo;
    		this.totalSum = totalSum;
    		this.url = url;
    		this.pageSize = pageSize;
    	}
    
    	public VariablePage(int pageNum, int totalSum, String url) {
    		pageNum = pageNum < 1 ? 1 : pageNum;
    		super.pageNo = pageNum;
    		this.totalSum = totalSum;
    		this.url = url;
    	}
    
    	public String getSplit() {
    		return split;
    	}
    
    	public void setSplit(String split) {
    		this.split = split;
    	}
    
    }

\#需要使用该分页标签的JSP 使用方法如下：

JSP 头部引入

<%@tagliburi=*"http://www.kevin.com/taglibs/page"*prefix=*"page"*%>

使用以下标签生成分页HTML代码

<page:htmlPagepageNo=*"*$\{pageNo\}*"*url=*"your\_url"*  totalSum=*"*$\{totalSum\}*"*showPage=*"10"*pageSize=*"12"*/>