<diego:with object="${Man}"> <diego:output property="name"/> </diego:with> |
<diego:with object="${people}"> <!--表示取得一个对象--> <diego:withCollection property="men"> <!--表示取得对象里的一个属性,这个属性是个 Collection,Collection里添加了许多man,每个man有名字和年龄--> <diego:output property="name"/> <!--取得name属性并显示--> </diego:withCollection> </diego:with> |
import org.apache.commons.beanutils.PropertyUtils; ...... property = PropertyUtils.getProperty(currentClass, propertyName); |
package diegoyun; import java.io.IOException; import javax.servlet.jsp.JspException; import javax.servlet.jsp.tagext.BodyTagSupport; import org.apache.taglibs.standard.lang.support.ExpressionEvaluatorManager; /** * @author chenys */ public class WithTag extends BodyTagSupport { private Object value = null; private Object output = null; public void setOutput(Object output) { this.output = output; } public Object getValue() { return value; } public void setValue(Object value)throws JspException { this.value = ExpressionEvaluatorManager.evaluate("value", value.toString(), Object.class, this, pageContext); } public int doStartTag() { return EVAL_BODY_INCLUDE; } public int doEndTag()throws JspException { try { pageContext.getOut().print(output); } catch (IOException e) { throw new JspException(e); } return EVAL_PAGE; } } |
package diegoyun; import javax.servlet.jsp.JspException; import javax.servlet.jsp.tagext.BodyTagSupport; import org.apache.commons.beanutils.PropertyUtils; /** * @author chenys */ public class NestedOutputTag extends BodyTagSupport { private String property = null; public void setProperty(String property) { this.property = property; } public int doEndTag()throws JspException { WithTag parent =(WithTag)getParent(); if(parent==null) throw new JspException("Can not find parent Tag "); try { Object propertyValue = PropertyUtils.getProperty(parent.getValue(), property); parent.setOutput(propertyValue); } catch (Exception e) { throw new JspException(e); } return EVAL_PAGE; } } |
package diegoyun.vo; /** * @author chenys */ public class Man { private String name = null; private int age = 0; public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } } |
<!--WithTag--> <tag> <name>with</name> <tag-class>diegoyun.WithTag</tag-class> <body-content>JSP</body-content> <attribute> <name>value</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> <!--OutputTag3--> <tag> <name>nestedout</name> <tag-class>diegoyun.NestedOutputTag</tag-class> <body-content>empty</body-content> <attribute> <name>property</name> <required>false</required> <rtexprvalue>false</rtexprvalue> </attribute> </tag> |
<%@ page language="java" %> <%@ page import="diegoyun.vo.*"%> <%@ taglib uri="/WEB-INF/tlds/diego.tld" prefix="diego"%> <html> <body bgcolor="#FFFFFF"> <% Man man = new Man(); man.setName("diego"); request.setAttribute("man",man); %> Test nested tag: <br> <diego:with value="${man}"> <diego:nestedout property="name"/> </diego:with> </body> </html> |
Test nested tag: diego |