SSH自定义标签
一、标签处理类：
package cn.conris.sys.form; import java.io.IOException; import java.util.Enumeration; import javax.servlet.http.HttpServletRequest; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspWriter; import javax.servlet.jsp.tagext.SimpleTagSupport; import javax.servlet.jsp.tagext.TagSupport; import cn.conris.sys.utils.PropertyUtil; public class PageTag extends TagSupport { private int pageSize = PropertyUtil.getPageSize(); // 每页要显示的记录数 private int pageNo = PropertyUtil.getPageNumber(); // 页号 private int recordCount; // 总记录数 private String url; // 目的地URL public void setPageSize(int pageSize) { this.pageSize = pageSize; } public void setPageNo(int pageNo) { this.pageNo = pageNo; } public void setRecordCount(int recordCount) { this.recordCount = recordCount; } public void setUrl(String url) { this.url = url; } // 主要的逻辑 @Override public int doStartTag() throws JspException { if(recordCount == 0){ return super.doStartTag(); } // 总页数 int pageCount = (recordCount + pageSize - 1) / pageSize; // 页号越界处理 if (pageNo > pageCount) { pageNo = pageCount; } if (pageNo < 1) { pageNo = 1; } StringBuilder sb = new StringBuilder(); sb.append("<form name='pageController' id='pageController' action='' method='post'> ") .append("<input type='hidden' id='pageNo' name='pageNo' value='" + pageNo + "' /> "); //------------------------------------ 获取所有請求中的参数 HttpServletRequest request = (HttpServletRequest) pageContext .getRequest(); Enumeration<String> enumeration = request.getParameterNames(); String name = null; String value = null; //把请求中的所有参数当作隐藏表单域在页面中写出) while (enumeration.hasMoreElements()) { name = enumeration.nextElement(); value = request.getParameter(name); // 去除页号 if (name.equals("pageNo")) { if (null != value && !"".equals(value)) { pageNo = Integer.parseInt(value); } continue; } sb.append("<input type='hidden' name='") .append(name) .append("' value='") .append(value) .append("'/> "); } //---------------------------------------------------- sb.append(" 共" + pageCount + "页, ") .append("当前第" + pageNo + "页  "); if (pageNo == 1) { sb.append("首页"); sb.append(" "); sb.append("上一页 "); } else { sb.append("<a href='#' onclick='turnOverPage(1)'>首页</a> "); sb.append(" "); sb.append("<a href='#' onclick='turnOverPage(") .append((pageNo - 1)).append(")'>上一页</a> "); } sb.append(" "); if (pageNo == pageCount) { sb.append("下一页"); sb.append(" "); sb.append("尾页 "); } else { sb.append("<a href='#' onclick='turnOverPage(") .append((pageNo + 1)).append(")'>下一页</a> "); sb.append(" "); sb.append("<a href='#' onclick='turnOverPage(").append(pageCount) .append(")'>尾页</a> "); } sb.append(" 跳到<select style='width:80px;' onChange='turnOverPage(this.value)'> "); for (int i = 1; i <= pageCount; i++) { if (i == pageNo) { sb.append(" <option value='") .append(i) .append("' selected='selected'>第") .append(i) .append("页</option> "); } else { sb.append(" <option value='") .append(i) .append("'>第") .append(i) .append("页</option> "); } } sb.append("</select> "); sb.append("  "); sb.append("</form> "); // 生成提交表单的JS sb.append("<script language='javascript'>"); // sb.append(" //翻页函数/t/n"); sb.append(" function turnOverPage(no){"); sb.append(" var form = document.pageController;"); // sb.append(" //页号越界处理"); sb.append(" if(no").append(">").append(pageCount).append(") {"); sb.append(" no=").append(pageCount).append(";"); sb.append(" }"); sb.append(" if(no").append("< 1){"); sb.append(" no=1;"); sb.append(" }"); sb.append(" form.").append("pageNo").append(".value=no;"); sb.append(" form.action='").append(url).append("';"); sb.append(" form.submit();"); sb.append(" }"); sb.append("</script>"); try { pageContext.getOut().println(sb.toString()); } catch (IOException e) { e.printStackTrace(); } return super.doStartTag(); } }
二、标签库描述文件：
<?xml version="1.0" encoding="UTF-8"?> <taglib version="2.0" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee web-jsptaglibrary_2_0.xsd"> <tlib-version>2.0</tlib-version> <short-name>my</short-name> <uri>http://conris/ModelSystem</uri> <tag> <description>通用分页标签</description> <name>pager</name> <tag-class>cn.conris.sys.form.PageTag</tag-class> <body-content>empty</body-content> <attribute> <name>pageNo</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>recordCount</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>pageSize</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>url</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib>
三\配置web.xml
<!-- 配置自定义标签 -->
<jsp-config>
<taglib>
<taglib-uri>/mytaglib</taglib-uri>
<taglib-location>/WEB-INF/classes/pageTag.tld</taglib-location>
</taglib>
</jsp-config>
四\把pageSize写在了配置文件里面，这样可以灵活的修改配置。
pageSize=5
pageNumber=1
读取配置文件的工具类
package cn.conris.sys.utils; import java.io.IOException; import java.io.InputStream; import java.util.Properties; public class PropertyUtil { private static Properties p = new Properties(); private static InputStream inputStream = null; static { inputStream = PropertyUtil.class .getResourceAsStream("/page.properties"); try { p.load(inputStream); } catch (IOException e) { e.printStackTrace(); } } public static int getPageSize() { return Integer.parseInt(p.getProperty("pageSize")); } public static int getPageNumber() { return Integer.parseInt(p.getProperty("pageNumber")); } public static void main(String[] args) { System.out.println(getPageSize()); } }
五,action处理类
public String listmap() { String name = extendAttribute.getName(); String type = extendAttribute.getType(); List<ExtendAttribute> list = null; Map<String, String> maps = new HashMap<String, String>(); if (name != null && !name.equals("")) { maps.put("name", name); } if (type != null && !type.equals("")) { maps.put("type", type); } list = extendAttributeService.find(maps); String pageNoStr = request.getParameter("pageNo"); int pageNo = PropertyUtil.getPageNumber(); if (pageNoStr != null && !pageNoStr.equals("")) { pageNo = Integer.parseInt(pageNoStr); } int recordCount = list.size(); int pageSize = PropertyUtil.getPageSize(); int startNo = (pageNo - 1) * pageSize; List<ExtendAttribute> result = null; if (recordCount <= pageSize) { result = list; } else { if(startNo + pageSize>recordCount){ result = list.subList(startNo, recordCount); }else{ result = list.subList(startNo, startNo + pageSize); } } request.setAttribute("recordCount", recordCount); request.setAttribute("pageNo", pageNo); request.setAttribute("pageSize", pageSize); request.setAttribute("list", result); // request.setAttribute("list", list); return "success"; }
六\引用分页标签
<div class="pagination pagination-centered"> <mytag:pager pageNo="${pageNo}" recordCount="${recordCount}" pageSize="${pageSize}" url="ExtendAttributeAction_listmap.action" /> </div>
七\条件查询时,把条件值回显,支持条件分页.
原理:点击分页条,调用action方法后会执行doStartTag()方法,标签会自动添加表单中所有属性值.
action中:
request.setAttribute("recordCount", recordCount); request.setAttribute("pageNo", pageNo); request.setAttribute("pageSize", pageSize); request.setAttribute("list", result); // request.setAttribute("list", list); request.setAttribute("name", name); request.setAttribute("type", type);
jsp回显:
<form id="serach" class="form-search" action="ExtendAttributeAction_listmap.action" method="post"> 扩展属性名称： <input type="text" class="input-medium span2" name="name" value="${name }"> 扩展属性类型： <select class="drop_down" name="type"> <c:choose> <c:when test="${type=='int'}"> <option value="">全部</option> <option value="int" selected="selected">整型</option> <option value="float">浮点型</option> <option value="varchar(256)">字符串型</option> </c:when> <c:when test="${type=='float'}"> <option value="">全部</option> <option value="int">整型</option> <option value="float" selected="selected">浮点型</option> <option value="varchar(256)">字符串型</option> </c:when> <c:when test="${type=='varchar(256)'}"> <option value="">全部</option> <option value="int">整型</option> <option value="float">浮点型</option> <option value="varchar(256)" selected="selected">字符串型</option> </c:when> <c:otherwise> <option value="">全部</option> <option value="int">整型</option> <option value="float">浮点型</option> <option value="varchar(256)">字符串型</option> </c:otherwise> </c:choose> </select> <button type="submit" class="btn"> <i class="icon-search"></i> 搜索 </button> </form>
