一个相当好的自定义标签---分页(一) -优快云博客

本文链接：https://blog.youkuaiyun.com/aguang110/article/details/83884395

发现在系统中有好多写得很好的代码,也不知道是哪位前辈留下来的.整理一下...
自定义分页标签库

1:在配置文件中配置

< taglib >

< taglib-uri > /WEB-INF/self-html.tld </ taglib-uri >

< taglib-location > /WEB-INF/self-html.tld </ taglib-location >

</ taglib >

2:在self-html.tld中page标签的配置

< tag >

< name > page </ name >

< tagclass > com.jbbis.netedu.common.util.taglib.PageTag </ tagclass >

< bodycontent > empty </ bodycontent >

< info > tag here </ info >

< attribute >

< name > name </ name >

< required > true </ required >

< rtexprvalue > false </ rtexprvalue >

</ attribute >

< attribute >

< name > pageNum </ name >

< required > false </ required >

< rtexprvalue > false </ rtexprvalue >

</ attribute >

< attribute >

< name > method </ name >

< required > false </ required >

< rtexprvalue > false </ rtexprvalue >

</ attribute >

< attribute >

< name > methodValue </ name >

< required > false </ required >

< rtexprvalue > true </ rtexprvalue >

</ attribute >

< attribute >

< name > form </ name >

< required > true </ required >

< rtexprvalue > false </ rtexprvalue >

</ attribute >

< attribute >

< name > action </ name >

< required > flase </ required >

< rtexprvalue > true </ rtexprvalue >

</ attribute >

< attribute >

< name > returnLevel </ name >

< required > flase </ required >

< rtexprvalue > true </ rtexprvalue >

</ attribute >

</ tag >

其实从这儿也可以看到在PageTag文件中是一些什么值了...

3:PageTag中的具体操作(精华全部在这儿啦)

/**/ /*

* Created on 2004-6-25

package com.jbbis.netedu.common.util.taglib;

import java.io.IOException;

import javax.servlet.jsp.JspException;

import javax.servlet.jsp.JspWriter;

import javax.servlet.jsp.tagext.TagSupport;

import com.jbbis.netedu.common.page.NullPage;

import com.jbbis.netedu.common.page.Page;

/** */ /**

* @author leo_deng

public class PageTag extends TagSupport

{

/**//* (non-Javadoc)

* @see javax.servlet.jsp.tagext.Tag#doStartTag()

private String name;

private String pageNum="pageNum";

private String method="method";

private String methodValue;

private String form="mainForm";

private String action;

private String returnLevel;

private final int CONST_FIRST=1;

private final int CONST_NEXT=2;

private final int CONST_PRIOR=3;

private final int CONST_LAST=4;

public int doStartTag() throws JspException

{

// TODO Auto-generated method stub

try

{

JspWriter out = pageContext.getOut() ;

Page page=(Page)pageContext.getRequest().getAttribute(name);

if(page==null)

page=NullPage.instance();

out.print(getHtml(page.getPageNumber(),page.getPageCount()));

out.print(getJs(page.getPageNumber(),page.getPageCount()));

//jspwriter是一个隐含对象，用于向jsp网页输出内容。输出的目标由

// pagecontext.getout提供

//向jsp网页上下文输出

}catch(IOException ioException)

{

throw new JspException(ioException.getMessage() );

}//catch

return(SKIP_BODY);

}

/**//*

* <

* <!--

* function page_next(){

* form.action=""

* form.pageNum=""

* form.method.value=""

* form.submit;

* }

* function page_prior()

* function page_first()

* funciotn page_last()

* //-->

* <div class="listbox_page">

第<input class="page_number" name="pageNum" value=""> <img src="page_go.gif" class="page_go">页

共 <span class="page_sum">1000</span> 页

</div>

* */

private String getJs(int pageNum,int totalNum)

{

StringBuffer sb=new StringBuffer();

sb.append("\n<script language=\"JavaScript\">\n<!--");

sb.append(printFunction("page_first",pageNum,totalNum,CONST_FIRST));

sb.append(printFunction("page_next",pageNum,totalNum,CONST_NEXT));

sb.append(printFunction("page_prior",pageNum,totalNum,CONST_PRIOR));

sb.append(printFunction("page_last",pageNum,totalNum,CONST_LAST));

getGoJs(sb,pageNum,totalNum);

sb.append("\n //-->\n</script>");

return sb.toString();

}

private void getGoJs(StringBuffer sb,int pageNum,int totalNum)

{

sb.append("function page_go(obj){\n");

sb.append("var page_number=document.getElementById(\"page_number\");\n");

sb.append("if( page_number.value != new Number(page_number.value))return alert(\"请输入正确的页数\");\n");

sb.append("if(page_number.value<1) page_number.value=1;if(page_number.value>");

sb.append(totalNum);

sb.append(")page_number.value=");

sb.append(totalNum);

sb.append(";\n");

sb.append("if(page_number.value!="+pageNum+")");

sb.append("submitForPageNum(obj);\n");

sb.append("}");

}

private StringBuffer printFunction(String function,int pageNumber,int totalNumber,int pageConst)

{

StringBuffer sb=new StringBuffer();

sb.append("\nfunction "+function+"(){");

sb.append("\nevent.returnValue=false;");

sb.append(printAction());

sb.append(printMethod());

//sb.append("\n"+this.form+".submit();\n}");

if(totalNumber>1)

{

switch(pageConst)

{

case CONST_FIRST:

if(pageNumber>1)

{

sb.append(printPageNum(String.valueOf(1)));

sb.append("\n submitForPageNum("+this.form+");");

}

break;

case CONST_LAST:

if(pageNumber<totalNumber)

{

sb.append(printPageNum(String.valueOf(totalNumber)));

sb.append("\n submitForPageNum("+this.form+");");

}

break;

case CONST_PRIOR:

if(pageNumber>1)

{

sb.append(printPageNum(String.valueOf(pageNumber-1)));

sb.append("\n submitForPageNum("+this.form+");");

}

break;

case CONST_NEXT:

if(pageNumber<totalNumber)

{

sb.append(printPageNum(String.valueOf(pageNumber+1)));

sb.append("\n submitForPageNum("+this.form+");");

}

break;

}

sb.append("\n}");

return sb;

}

/**//*

private StringBuffer printFunction(String function,String pageNum,int pageConst){

StringBuffer sb=new StringBuffer();

sb.append("\nfunction "+function+"(){");

sb.append("\nevent.returnValue=false;");

sb.append(printAction());

sb.append(printMethod());

sb.append(printPageNum(pageNum));

//sb.append("\n"+this.form+".submit();\n}");

sb.append("\n submitForPageNum("+this.form+");\n}");

sb.append("\n}");