jsp 自定义标签-SimpleTagSupport 使用笔记

项目需求：jsp页面自定义搜索行,点击a标签搜索分类，重新刷新页面，select标签加载数据后由js控制搜索请求链接。

内容：搜索行主要包括A标签 和select标签，a标签生成时带href，具体内容由request获取的属性和属性值生成。select标签实现页面刷新时加载初始化数据即可。

这里只需要实现三个自定义标签即可：

1.父标签：

selectlineTag,主要存放表示搜索指定分类的初始化值。

2.子标签：

ATag:a标签，搜索某类的指定值，点击后带上这个标签代表的查询分类值，请求后台查询。

SelectTag:select标签。

custom.tld 放在WEB-INF/文件夹下，自定义标签所需jar包：jsp-api.jar,servlet-api.jar

<taglib>
<tlib-version>1.0</tlib-version>
<jsp-version>2.0</jsp-version>
<short-name>search row tld</short-name>
<tag>
<name>searchline</name>
<tag-class>com.test.tag.SearchlineTag</tag-class>
<body-content>scriptless</body-content>
<attribute>
<name>defaulvalue</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>选择行的默认值（选择行包括a 和select标签，默认值包括这些标签对应的值）。缺省值：""。</description>
</attribute>
<attribute>
<name>defaultcls</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>行选择其子项被选中时的class样式缺省值：""。</description>
</attribute>
<attribute>
<name>basehref</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>子项a标签href搜索链接地址：""。</description>
</attribute>
<attribute>
<name>defaultsplit</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>默认值分组符号，有时候默认值对应多个组件的值，多个select时用到：""。</description>
</attribute>
</tag>

<tag>
<name>select</name>
<tag-class>com.test.tag.selectTag</tag-class>
<body-content>scriptless</body-content>
<attribute>
<name>type</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>select类型，值：num|""。num数值时数据可以传start下拉选框的开始范围,end,step每个下拉项步长。属性缺省值：""。</description>
</attribute>
<attribute>
<name>displayField</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>缺省值：""。</description>
</attribute>
<attribute>
<name>valueField</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>缺省值：""。</description>
</attribute>
<attribute>
<name>defaultValNo</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>对应父标签defaultvalue中的值第几个值，"杭州-下城区",0:杭州，1：下城区。缺省值：""。</description>
</attribute>
<attribute>
<name>defaultValNo</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>对应父标签defaultvalue中的值第几个值，"杭州-下城区",0:杭州，1：下城区。缺省值：""。</description>
</attribute>
<attribute>
<name>cls</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>select标签本身需要带有的样式。缺省值：""。</description>
</attribute>
<attribute>
<name>style</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>。缺省值：""。</description>
</attribute>
<attribute>
<name>data</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>select标签数据内容。缺省值：""。</description>
</attribute>
<attribute>
<name>show</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>初始化时是否展示这个select html标签，show可选值：select 有选中值时显示,all 显示,no 不显示。 缺省值：""。</description>
</attribute>
<attribute>
<name>start</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>type属性为num时，如年份表示option中年份开始时间。 缺省值：""。</description>
</attribute>
<attribute>
<name>end</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>type属性为num时，如年份表示option中年份结束时间。 缺省值：""。</description>
</attribute>
<attribute>
<name>step</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>type属性为num时，表示option中年份值步长。 缺省值：""。</description>
</attribute>
<attribute>
<name>prompText</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>下拉框不代表任何选中的值,一般放在下拉选框的第一个选项，如“请选择”</description>
</attribute>
</tag>
<tag>
<name>a</name>
<tag-class>com.test.tag.ATag</tag-class>
<body-content>scriptless</body-content>
<attribute>
<name>type</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>href标记的属性值。缺省值：""。</description>
</attribute>
<attribute>
<name>cls</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>a标签的样式。缺省值：""。</description>
</attribute>
<attribute>
<name>needhref</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>是否需要href标签，根据父标签的basehref生成。缺省值：""。</description>
</attribute>
<attribute>
<name>text</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>a标签的文本内容。缺省值：""。</description>
</attribute>
<attribute>
<name>key</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>查询中a标签代表的字段名，生成href时在basehref基础上修改。缺省值：""。</description>
</attribute>
<attribute>
<name>value</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>a标签的值和其父标签的defaultvalue对应，且和key对应。缺省值：""。</description>
</attribute>
<attribute>
<name>basehref</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
<description>父级标签带了，这里就不需要了。搜索链接地址：""。</description>
</attribute>
</tag>
</taglib>

父级标签：searchlineTag

package com.test.tag;

import java.io.IOException;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.SimpleTagSupport;

public class SearchlineTag extends SimpleTagSupport {
private String label;
private String basehref;
private String defaultcls;
private String defaulvalue;
private String defaultsplit;

public String getDefaultsplit() {
if (defaultsplit == null || "".equals(defaultsplit)) {
return "-";
}
return defaultsplit;
}

//此处省略 get/set....
public void doTag() throws JspException, IOException {

//SearchlineTag 标签作用显示标签体，以及作为其他两个标签的父标签；
getJspBody().invoke(null);
}

}

子标签：A标签实现

public class ATag extends SimpleTagSupport {

private String key;
private String value;
private String text;
private String needhref;
private String type;
private String cls;
private String basehref;

//此处省略 get/set.....

public void doTag() throws JspException, IOException {
PageContext pageContext = (PageContext) this.getJspContext();
ServletRequest request = pageContext.getRequest();
JspFragment jspFragment = this.getJspBody();
String content = "";
if (this.te
ddab
xt != null) {
content = this.text;
}
SearchlineTag parent = null;

if (getParent() instanceof SearchlineTag) {
parent = (SearchlineTag) getParent();
} else {
// 如果在父级和子标签中还嵌套了其他标签如<c:if>要访问父级以上的标签就用这个。
parent = (SearchlineTag) ATag.findAncestorWithClass(this, SearchlineTag.class);
}

String hrefstr = "";
String clsStr = "";
String adefaultv = "";
String defaultcls = "";
String pbasehref = "";
if (parent != null) {
adefaultv = parent.getDefaulvalue();
defaultcls = parent.getDefaultcls();
pbasehref = parent.getBasehref();
}

if (adefaultv.equals(this.value) && defaultcls != "") {
clsStr = " class ='" + (this.cls != null ? this.cls : "") + " " + defaultcls + "'";
} else {
clsStr = " class ='" + (this.cls != null ? this.cls : "") + "'";
}
if ("false".equals(this.needhref)) {
hrefstr = " href='javascript:void(0);' ";
} else if ("true".equals(this.needhref)) {
if (this.basehref != null) {
pbasehref = this.basehref;
}
hrefstr = " href='" + replaceHref(pbasehref, this.key, this.value) + "' ";
}

JspWriter out = getJspContext().getOut();
String outstr = "";
outstr = "<a ";
outstr += hrefstr + clsStr;
outstr += ">" + content + "</a>";
out.println(outstr);

}

//替换搜索链接中标签代表的键和值
public String replaceHref(String baseHref, String replaceKey, String replaceValue) {

if (replaceKey == null || "".equals(replaceKey)) {
return baseHref;
}
if (replaceValue == null) {
replaceValue = "";
}
String[] bhref = baseHref.split("\\?");
String[] paramhref = null;
List newParam = new ArrayList();
boolean ischecked = false;
String newHref = "";
if (bhref.length > 1) {
paramhref = bhref[1].split("&");
}

if (paramhref != null) {
int size = paramhref.length;
for (int i = 0; i < size; i++) {
String ps = paramhref[i];
String[] ins = ps.split("=");
if (replaceKey.equals(ins[0])) {
String inns = "" + ins[0] + "=" + replaceValue;
newParam.add(inns);
ischecked = true;
} else {
newParam.add(ps);
}
}
}

if (!ischecked) {
newParam.add("" + replaceKey + "=" + replaceValue);
}
int newsize = newParam.size();
for (int k = 0; k < newsize; k++) {
newHref += newParam.get(k).toString();
if (k < newsize - 1) {
newHref += "&";
}
}
return bhref[0] + "?" + newHref;
}
}

select标签实现：

public class selectTag extends SimpleTagSupport {
private String data;
private String key;
private String value;
private String text;
private String cls;
private String style;
private String valueField;
private String displayField;
private String defaultValNo;
private String show;
private String start;
private String end;
private String step;
private String type;
private String prompText;

//此处省略get/set。。。 z这里吧属性和tld中的属性对应

public void doTag() throws JspException, IOException {
PageContext pageContext = (PageContext) this.getJspContext();
ServletRequest request = pageContext.getRequest();
String selectdata = this.data != null ? this.data : "[]";
String content = "";
String clsStr = "";
Integer startsel = null;
Integer endsel = null;
Integer stepsel = null;
if (this.start != null) {
try {
startsel = Integer.parseInt(this.start);
} catch (Exception e) {
}
}

if (this.end != null) {
try {
endsel = Integer.parseInt(this.end);
} catch (Exception e) {
}
}
if (this.step != null) {
try {
stepsel = Integer.parseInt(this.step);
} catch (Exception e) {
}
}

if (this.text != null) {
content = this.text;
}
if (this.valueField == null) {
this.valueField = "value";
}
if (this.displayField == null) {
this.displayField = "text";
}
if (this.defaultValNo == null) {
this.defaultValNo = "0";
}
if (this.cls == null) {
this.cls = "";
} else {
clsStr = " class='" + this.cls + "'";
}

if (this.style == null) {
this.style = "";
}

if (this.show == null) {
this.show = "all";
}
if (this.type == null) {
this.type = "";
}
SearchlineTag parent = null;
if (getParent() instanceof SearchlineTag) {
parent = (SearchlineTag) getParent();
} else {
parent = (SearchlineTag) ATag.findAncestorWithClass(this, SearchlineTag.class);
}

String optionstr = "";
String seloptionstr = "";
String adefaultv = "";
String defaultcls = "";
String pbasehref = "";
String defaultsplit = "-";
String[] adefaultvs = null;
if (parent != null) {
adefaultv = parent.getDefaulvalue();
defaultcls = parent.getDefaultcls();
pbasehref = parent.getBasehref();
defaultsplit = parent.getDefaultsplit();
}
if (adefaultv != null && !"".equals(adefaultv)) {
adefaultvs = adefaultv.split(defaultsplit);// defaultsplit:"-"
int index = Integer.parseInt(this.defaultValNo);
if (index < adefaultvs.length) {
adefaultv = adefaultvs[index];
} else {
adefaultv = null;
}
}

if (!"".equals(selectdata)) {
JSONArray datajson = JSONArray.fromObject(selectdata);
int size = datajson.size();
for (int k = 0; k < size; k++) {
Map map2 = (Map) datajson.get(k);
String val = (String) map2.get(this.valueField);
String textv = (String) map2.get(this.displayField);
if (adefaultv != null && val.equals(adefaultv)) {
seloptionstr = "<option value='" + val + "' selected>" + textv + "</option>";
}

optionstr += "<option value='" + val + "' >" + textv + "</option>";
}
}

if ("num".equals(this.type) && ("[]".equals(selectdata) || "".equals(selectdata)) && startsel != null
&& endsel != null && stepsel != null) {// year
// 的值是数值类型select。
Integer numV = null;
try {
numV = Integer.parseInt(adefaultv);
} catch (Exception e) {
numV = null;
}
if (stepsel < 0) {
for (int k = startsel; k >= endsel; k = k + (stepsel)) {

if (adefaultv != null && numV != null && k == numV) {
seloptionstr = "<option value='" + k + "' selected>" + k + "</option>";
}
optionstr += "<option value='" + k + "' >" + k + "</option>";
}
} else if (stepsel > 0) {
for (int k = startsel; k <= endsel; k = k + stepsel) {
if (adefaultv != null && numV != null && k == numV) {
seloptionstr = "<option value='" + k + "' selected>" + k + "</option>";
}
optionstr += "<option value='" + k + "' >" + k + "</option>";
}
} else {
if (adefaultv != null && numV != null && startsel == numV) {
seloptionstr = "<option value='" + startsel + "' selected>" + startsel + "</option>";
}
optionstr += "<option value='" + startsel + "' >" + startsel + "</option>";
}
}

JspWriter out = getJspContext().getOut();
String outstr = "";
if ("no".equals(this.show) || ("select".equals(this.show) && "".equals(seloptionstr))) {
clsStr += "  style='" + this.style + ";display:none;'";
} else if (!"".equals(this.style)) {
clsStr += "  style='" + this.style + "'";
}
if (this.prompText != null) {
if ("".equals(seloptionstr)) {// 未有选中值，提示的内容默认选中。
seloptionstr = "<option value='请选择' selected>" + this.prompText + "</option>";
} else {
seloptionstr += "<option   value='请选择' >" + this.prompText + "</option>";
}
}
outstr = "<select ";
outstr += clsStr;
outstr += ">" + seloptionstr + optionstr + "</select>";
out.println(outstr);
}
}

jsp使用：

<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib uri="/WEB-INF/custom.tld" prefix="cst" %>
<%@page import="java.net.URLEncoder"%>
<%@page import="java.util.*"%>
<%@page import="java.text.*"%>
<%@page import="net.sf.json.JSONArray"%>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title></title>
</head>
<body >

<%
request.setCharacterEncoding("UTF-8");
//String key = java.net.URLEncoder.encode(request.getParameter("key"), "UTF-8");
String key ="a";//搜索关键字
String area = "";
String time= "";//生成时间
String issue_time ="2014-2017";//发布时间
String pageses= "";
String parentarea = "";
String subarea = "";
request.setAttribute("parentarea","[{\"name\":\"杭州\"},{\"name\":\"绍兴\"},{\"name\":\"湖州\"}]");
request.setAttribute("subarea","[{\"name\":\"拱墅区\"},{\"name\":\"西湖区\"},{\"name\":\"上城区\"}]");

String basehref="search?key="+key+"&area="+area+"&time="+time
+"&issue_time="+issue_time+"&pageses="+pageses;
String yeardata="";
Date myDate = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");
String startyear= dateFormat.format(myDate.getTime());
request.setAttribute("start",startyear);
request.setAttribute("end",Integer.parseInt(startyear)-100);
String hasLogin = request.getAttribute("isLogin") != null ? request.getAttribute("isLogin").toString() : "";
%>
<div class="area">
<span>地        区：</span>
<cst:searchline  defaultcls="onclick" defaulvalue="<%=area%>" defaultsplit="-" basehref="<%=basehref %>"  >
<cst:a needhref="true"   key="area" value=""  text="不限" ></cst:a>
<cst:select prompText="请选择" cls="regon" defaultValNo="0"  data="${parentarea}" displayField="text" valueField="value">
</cst:select>
<cst:select  prompText="请选择" cls="regonin" defaultValNo="1" show="select" data="${subarea}" displayField="text" valueField="value" >
</cst:select>
</cst:searchline>
</div>
<div class="issue_time">
<span>发布时间：</span>
<cst:searchline  defaultcls="onclick" defaulvalue="<%=issue_time%>" defaultsplit="-" basehref="<%=basehref %>"  >
<cst:a needhref="true"   key="issue_time" value=""  text="不限" ></cst:a>
<cst:a needhref="true"   key="issue_time" value="本月"  text="本月" ></cst:a>
<cst:a needhref="true"   key="issue_time" value="本年"  text="本年" ></cst:a>
<cst:a needhref="true"   key="issue_time" value="近三年"  text="近三年" ></cst:a>
<cst:a needhref="true"   key="issue_time" value="近五年"  text="近五年" ></cst:a>
<cst:a needhref="true"   key="issue_time" value="五年以上"  text="五年以上" ></cst:a>
<em class="confim">
<cst:select cls="yeah3" prompText ="请选择" defaultValNo="0" type="num" start="${start}" end="${end}" step="-1">
</cst:select>
<cst:select  cls="yeah4" prompText ="请选择" defaultValNo="1" type="num"  start="${start}" end="${end}" step="-1" >
</cst:select>年</em>		<i id="confim">确认</i>
</cst:searchline>
</div>

<div class="time">
<span>生成时间：</span>
<cst:searchline  defaultcls="onclick" defaulvalue="<%=time%>" defaultsplit="-" basehref="<%=basehref %>"  >
<cst:a needhref="true"   key="time" value=""  text="不限" ></cst:a>
<cst:a needhref="true"   key="time" value="本月"  text="本月" ></cst:a>
<cst:a needhref="true"   key="time" value="本年"  text="本年" ></cst:a>
<cst:a needhref="true"   key="time" value="近三年"  text="近三年" ></cst:a>
<cst:a needhref="true"   key="time" value="近五年"  text="近五年" ></cst:a>
<cst:a needhref="true"   key="time" value="五年以上"  text="五年以上" ></cst:a>
<em class="confim">
<cst:select cls="yeah1" prompText ="请选择"   defaultValNo="0" type="num" start="${start}" end="${end}" step="-1">
</cst:select>
<cst:select  cls="yeah2" prompText ="请选择"  defaultValNo="1" type="num"  start="${start}" end="${end}" step="-1" >
</cst:select>年</em>		<i id="confim">确认</i>
</cst:searchline>
</div>
</body>
</html>

el表达式可参考：http://blog.csdn.net/zdwzzu2006/article/details/4672383

el存取变量数据，如${name}，表示取出某一范围中名称为name的变量，如果未指定范围，它会从Page、request、session、application范围查找。

jsp2tag标签: http://www.ibm.com/developerworks/cn/java/j-lo-jsp2tag/