Java tutorial
/* * Copyright 2004-2005 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.codehaus.groovy.grails.web.taglib.jsp; import org.apache.commons.lang.StringUtils; import org.codehaus.groovy.grails.web.taglib.GrailsTagRegistry; import org.codehaus.groovy.grails.web.taglib.RenderInputTag; import org.codehaus.groovy.grails.web.pages.GroovyPage; import org.springframework.beans.InvalidPropertyException; import org.springframework.web.servlet.tags.RequestContextAwareTag; import org.springframework.web.util.ExpressionEvaluationUtils; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspTagException; import java.io.Writer; import java.util.Map; import java.util.HashMap; /** * A JSP facade that delegates to the Grails RenderInputTag (@see * org.codehaus.groovy.grails.web.taglib.RenderInputTag). * * @author Graeme Rocher */ public class JspRenderInputTag extends RequestContextAwareTag { private static final long serialVersionUID = 2807429431970194614L; private String bean; private String property; @Override protected int doStartTagInternal() throws Exception { if (StringUtils.isBlank(property)) { throw new JspTagException("Tag [renderInput] missing required attribute [property]"); } if (StringUtils.isBlank(bean)) { throw new JspTagException("Tag [renderInput] missing required attribute [bean]"); } if (!ExpressionEvaluationUtils.isExpressionLanguage(bean)) { throw new JspTagException("Attribute [bean] of tag [renderInput] must be a JSTL expression"); } @SuppressWarnings("unused") Writer out = pageContext.getOut(); try { Object beanInstance = ExpressionEvaluationUtils.evaluate("bean", bean, Object.class, pageContext); if (beanInstance == null) { throw new JspTagException("Bean [" + bean + "] referenced by tag [renderInput] cannot be null"); } GrailsTagRegistry tagRegistry = GrailsTagRegistry.getInstance(); Map<String, Object> tagContext = new HashMap<String, Object>(); tagContext.put(GroovyPage.REQUEST, pageContext.getRequest()); tagContext.put(GroovyPage.RESPONSE, pageContext.getResponse()); tagContext.put(GroovyPage.SERVLET_CONTEXT, pageContext.getServletContext()); RenderInputTag tag = (RenderInputTag) tagRegistry.newTag(RenderInputTag.TAG_NAME); tag.init(tagContext); tag.setBean(beanInstance); tag.setProperty(property); tag.doStartTag(); } catch (InvalidPropertyException ipe) { throw new JspException("Attribute [property] with value [" + property + "] is not a valid property of bean [" + bean + "] in tag [renderInput]", ipe); } return SKIP_BODY; } public String getBean() { return bean; } public void setBean(String bean) { this.bean = bean; } public String getProperty() { return property; } public void setProperty(String property) { this.property = property; } }