jsp 自定义分页标签

网络整理 - 07-27

花了一上午简单研究了下自定义标签。就弄了个自定义的分页标签。代码没有怎么仔细优化。先贴上来，：）

1,标签的实现类NumenTag.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;

/** *//**
* 自定义的分页标签
*
* @author 马万林
*
*/
public class NumenTag extends TagSupport {

private String url = null;

private Result result;

private String page = null;

private String[] p;

private Map kv = new HashMap();

private List key = null;

    /** *//**
     * 分离参数
     * @param params
     */
    public void setParams(String params) {
        key = new ArrayList();
        p = params.split(";");
        for (int i = 0; p.length>1&&i < p.length; i++) {
            kv.put(p[i].split(":")[0], p[i].split(":")[1]);
            key.add(p[i].split(":")[0]);
        }
    }

    /** *//**
     * 分页的结果
     * @param result
     */
    public void setResult(String result) {
        this.result = (Result) pageContext.getRequest().getAttribute("result");
        this.page = (String) pageContext.getRequest().getAttribute("page");
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public int doStartTag() throws JspException {
        StringBuffer sb = null;
        if (result != null && result.getContent() != null
                && result.getContent().size() > 0) {
            sb = new StringBuffer("分页: ");
            if (result.getPage().getHasPrePage()){
                sb.append("<a href='").append(url);
                if (url.indexOf("?") == -1)
                    sb.append("?page=1");
                else
                    sb.append("&page=1");
                linkParams(sb);
                sb.append("'>").append("首页").append("</a>").append(" | ");
                sb.append("<a href='").append(url);
                if (url.indexOf("?") == -1)
                    sb.append("?page=").append(
                            result.getPage().getPreviousPage());
                else
                    sb.append("&page=").append(
                            result.getPage().getPreviousPage());
                linkParams(sb);
                sb.append("'>").append("上页").append("</a>").append(" | ");
            }
            if (result.getPage().getHasNextPage()) {
                sb.append("<a href='").append(url);
                if (url.indexOf("?") == -1)
                    sb.append("?page=").append(result.getPage().getNextPage());
                else
                    sb.append("&page=").append(result.getPage().getNextPage());
                linkParams(sb);
                sb.append("'>").append("下页").append("</a>").append(" | ");
                sb.append("<a href='").append(url);
                if (url.indexOf("?") == -1)
                    sb.append("?page=").append(result.getPage().getTotalPage());
                else
                    sb.append("&page=").append(result.getPage().getTotalPage());
                linkParams(sb);
                sb.append("'>").append("尾页").append("</a>");
            }
            sb
                    .append(" 跳转到:<select >");
            int s = result.getPage().getTotalCount();
            for (int i = 1; i <= s; i++) {
                sb.append("<option value=").append(i);
                if (Integer.parseInt(page) == i)
                    sb.append(" selected");
                sb.append(">第").append(i).append("页</option>");
            }
            sb.append("</select>");
            sb.append("<script language=javascript>");
            sb.append("function goPage(page){").append("window.location='")
                    .append(url);
            if (url.indexOf("?") == -1)
                sb.append("?page='+").append("page");
            else
                sb.append("&page='+").append("page");
            sb.append("+'");
            linkParams(sb);
            sb.append("';");
            sb.append("}");
            sb.append("</script>");
        }
        try {
            if (sb != null) {
                JspWriter out = pageContext.getOut();
                out.print(sb);
            }
        } catch (Exception e) {
            throw new JspException(e);
        }
        return EVAL_PAGE;
    }

    /** *//**
     * 链接参数处理
     * @param sb
     */
    private void linkParams(StringBuffer sb) {
        for (int i = 0; i < key.size(); i++) {
            sb.append("&").append(key.get(i)).append("=").append(
                    kv.get(key.get(i)));
        }
    }

}

2,标签定义文件numentag.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>1.0</tlib-version>
    <jsp-version>1.2</jsp-version>
    <short-name>numen</short-name>
    
    <tag>
        <name>out</name>
        <tag-class>cn.cityyouth.util.NumenTag</tag-class>
        <body-content>empty</body-content>
        <attribute>
            <name>url</name>
            <required>true</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>result</name>
            <required>true</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>params</name>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
    </tag>
</taglib>

3.js

<%@ page contentType="text/html; charset=utf-8"%>
<%@ include file="/common/taglibs.jsp"%>
<%@ taglib uri="/WEB-INF/numentag.tld" prefix="n"%>
<html>
<head>
</head>
<body>
<table>
<tr><td>
<n:out url="test.do" result="result" params="${type}"/>
</td></tr>
</table>
</body>
</html>