Java 如何生成';返回搜索结果';JSTL的url或JSP中的自定义库,包含所有参数并指定排除参数?
我想在JSP中生成一个返回搜索结果的“”url。我使用JSTL taglib,它可以工作:Java 如何生成';返回搜索结果';JSTL的url或JSP中的自定义库,包含所有参数并指定排除参数?,java,jsp,jstl,taglib,Java,Jsp,Jstl,Taglib,我想在JSP中生成一个返回搜索结果的“”url。我使用JSTL taglib,它可以工作: <c:url var="backUrl" value="list.html"> <c:forEach items="${param}" var="currentParam"> <c:param name="${currentParam.key}" value="${currentParam.value}"/> </c:forEach
<c:url var="backUrl" value="list.html">
<c:forEach items="${param}" var="currentParam">
<c:param name="${currentParam.key}" value="${currentParam.value}"/>
</c:forEach>
</c:url>
<a href="${backUrl}">< return to search results / list</a>
我希望有一个更好的解决方案,例如使用一行代码生成反向链接的自定义库,示例如下:
<tagname:url var="backUrl" value="list.html" includeAllParams="true" excludeParams="id, question"/>
<a href="${backUrl}">< return to search results / list</a>
因为,我想使用exclude参数重新使用此代码:
<c:url var="backUrl" value="list.html">
<c:forEach items="${param}" var="currentParam">
<c:if test="${currentParam.key ne 'id'}">
<c:param name="${currentParam.key}" value="${currentParam.value}"/>
</c:if>
</c:forEach>
</c:url>
<a href="${backUrl}">< return to search results / list</a>
我的问题是什么是最佳实践,以及如何创建自定义库以生成一行链接:
<tagname:url var="backUrl" value="list.html" includeAllParams="true" excludeParams="id, question"/>
谢谢。好的,我已经创建了一个自定义选项卡: 类别:
package com.test;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import org.apache.taglibs.standard.lang.support.ExpressionEvaluatorManager;
import org.apache.taglibs.standard.tag.el.core.UrlTag;
public class CustomUrlTag extends UrlTag {
private static final long serialVersionUID = 1L;
private String includeAllParams;
private String excludeParams;
public CustomUrlTag() {
init();
}
@Override
public int doStartTag() throws JspException {
return super.doStartTag();
}
@Override
public int doEndTag() throws JspException {
if (isIncludeAllParam()) {
final HttpServletRequest request = (HttpServletRequest) this.pageContext.getRequest();
// iterate over request parameters
final List<String> requestParameterNames = Collections.list((Enumeration<String>) request.getParameterNames());
// exclude parameters
if (null != excludeParams) {
for (final String currentExcludeParam : excludeParams.split("[,]")) {
requestParameterNames.remove(currentExcludeParam);
}
}
for (final String parameterName : requestParameterNames) {
// add parameters
addParameter(parameterName, request.getParameter(parameterName));
}
}
return super.doEndTag();
}
@Override
public void release() {
super.release();
init();
}
private void init() {
includeAllParams = null;
}
private boolean isIncludeAllParam() throws JspException {
final Object r = ExpressionEvaluatorManager.evaluate("includeAllParams", includeAllParams,
java.lang.Boolean.class, this, pageContext);
if (r != null) {
return ((Boolean) r).booleanValue();
}
return false;
}
public void setIncludeAllParams(String includeAllParams) {
this.includeAllParams = includeAllParams;
}
public void setExcludeParams(String excludeParams) {
this.excludeParams = excludeParams;
}
}
package.com.test;
导入java.util.Collections;
导入java.util.Enumeration;
导入java.util.List;
导入javax.servlet.http.HttpServletRequest;
导入javax.servlet.jsp.JspException;
导入org.apache.taglibs.standard.lang.support.ExpressionEvaluationManager;
导入org.apache.taglibs.standard.tag.el.core.UrlTag;
公共类CustomUrlTag扩展了UrlTag{
私有静态最终长serialVersionUID=1L;
私有字符串includealParams;
私有字符串排除参数;
公共CustomUrlTag(){
init();
}
@凌驾
public int doStartTag()抛出JSPEException{
返回super.doStartTag();
}
@凌驾
public int doEndTag()抛出JspException{
如果(isIncludeAllParam()){
最终HttpServletRequest=(HttpServletRequest)this.pageContext.getRequest();
//迭代请求参数
final List requestParameterNames=Collections.List((枚举)request.getParameterNames());
//排除参数
if(null!=排除参数){
for(最终字符串currentExcludeParam:excludeParams.split(“[,])){
requestParameterNames.remove(currentExcludeParam);
}
}
for(最终字符串参数名称:RequestParameterName){
//添加参数
addParameter(parameterName,request.getParameter(parameterName));
}
}
返回super.doEndTag();
}
@凌驾
公开无效释放(){
super.release();
init();
}
私有void init(){
includealParams=null;
}
私有布尔值isIncludeAllParam()抛出JSPEException{
最终对象r=expressioneValuationManager.evaluate(“includealParams”,includealParams,
java.lang.Boolean.class,this,pageContext);
如果(r!=null){
返回((布尔)r).booleanValue();
}
返回false;
}
公共void集合includealParams(字符串includealParams){
this.includealParams=includealParams;
}
public void setExcludeParams(字符串excludeParams){
this.excludeParams=excludeParams;
}
}
tld:
创建带有可选查询参数的URL。
自定义URL
com.test.CustomUrlTag
JSP
已导出的作用域变量的名称
已处理的url。作用域变量的类型为
一串
变量
假的
假的
要处理的URL。
价值
真的
真的
includealParams
真的
真的
排除参数
假的
真的
在jsp中:
<%@ taglib prefix="thePrefix" uri="http://www.test.com/project/tags" %>
<thePrefix:customUrl var="backUrl" value="list.html" includeAllParams="true" excludeParams="id"/>
那么,问题到底是什么?最佳做法是什么?如何创建自定义库以生成一行链接:也许您可以编写自己的标记。
<%@ taglib prefix="thePrefix" uri="http://www.test.com/project/tags" %>
<thePrefix:customUrl var="backUrl" value="list.html" includeAllParams="true" excludeParams="id"/>