一、值栈简介：
二、OGNL引入：
com.cy.action.HelloAction.java:
package com.cy.action; import java.util.Map; import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.ValueStack; public class HelloAction extends ActionSupport{
private static final long serialVersionUID = 1L; @Override
public String execute() throws Exception {
ActionContext actionContext = ActionContext.getContext();
ValueStack valueStack = actionContext.getValueStack();
valueStack.set("name", "张三(valueStack)");
valueStack.set("age", 11); Map<String, Object> session = actionContext.getSession();
session.put("name", "王五(session)");
session.put("age", 13); Map<String, Object> application = actionContext.getApplication();
application.put("name", "赵六(application)");
application.put("age", 14); return SUCCESS;
} }
struts.xml:
<struts>
<package name="manage" namespace="/" extends="struts-default">
<action name="hello" class="com.cy.action.HelloAction">
<result name="success">success.jsp</result>
</action>
</package>
</struts>
success.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
request.setAttribute("name", "李四(request)");
request.setAttribute("age", 12); pageContext.setAttribute("name", "小沛(page)");
pageContext.setAttribute("age", "18");
%>
</head>
<body>
获取狭义上的值栈数据：<s:property value="name"/>
<s:property value="age"/><br>
请求参数：<s:property value="#parameters.name"/>
<s:property value="#parameters.age"/><br>
request：<s:property value="#request.name"/>
<s:property value="#request.age"/><br>
session：<s:property value="#session.name"/>
<s:property value="#session.age"/><br>
application：<s:property value="#application.name"/>
<s:property value="#application.age"/><br>
attr取值：<s:property value="#attr.name"/>
<s:property value="#attr.age"/><br>
</body>
</html>
测试结果：
三、OGNL访问复杂对象：
四、OGNL访问静态属性和静态方法：
com.cy.model.Student.java:
package com.cy.model;
public class Student {
private String name;
private int age;
public Student() {
super();
// TODO Auto-generated constructor stub
}
public Student(String name, int age) {
super();
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
com.cy.common.MyStatic.java:静态属性和静态方法：
package com.cy.common;
public class MyStatic {
public static final String str = "好好学习";
public static String print(){
return "天天向上";
}
}
com.cy.action.HelloAction.java中存入javaBean、List、Map:
package com.cy.action; import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map; import com.cy.model.Student;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.ValueStack; public class HelloAction extends ActionSupport{
private static final long serialVersionUID = 1L; private Student student;
private List<Student> students;
private Map<String,Student> studentMap; public Map<String, Student> getStudentMap() {
return studentMap;
} public void setStudentMap(Map<String, Student> studentMap) {
this.studentMap = studentMap;
} public List<Student> getStudents() {
return students;
} public void setStudents(List<Student> students) {
this.students = students;
} public Student getStudent() {
return student;
} public void setStudent(Student student) {
this.student = student;
} @Override
public String execute() throws Exception {
ActionContext actionContext = ActionContext.getContext();
ValueStack valueStack = actionContext.getValueStack();
valueStack.set("name", "张三(valueStack)");
valueStack.set("age", 11); Map<String, Object> session = actionContext.getSession();
session.put("name", "王五(session)");
session.put("age", 13); Map<String, Object> application = actionContext.getApplication();
application.put("name", "赵六(application)");
application.put("age", 14); student = new Student("小八", 15); students=new ArrayList<Student>();
students.add(new Student("老九",13));
students.add(new Student("老十",14)); studentMap=new HashMap<String,Student>();
studentMap.put("goodStudent", new Student("学霸",20));
studentMap.put("badStudent", new Student("学渣",19)); return SUCCESS;
} }
struts.xml配置，开启ognl允许访问静态方法：
<struts>
<!-- 允许OGNL访问静态方法 -->
<constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant> <package name="manage" namespace="/" extends="struts-default">
<action name="hello" class="com.cy.action.HelloAction">
<result name="success">success.jsp</result>
</action> </package> </struts>
success.jsp，通过ognl来取值：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
ognl访问javaBean对象：<s:property value="student.name"/>
<s:property value="student.age"/><br>
ognl访问List集合：<s:property value="students[0].name"/>
<s:property value="students[0].age"/>
<s:property value="students[1].name"/>
<s:property value="students[1].age"/><br/>
ognl访问Map：<s:property value="studentMap['goodStudent'].name"/>
<s:property value="studentMap['goodStudent'].age"/>
<s:property value="studentMap['badStudent'].name"/>
<s:property value="studentMap['badStudent'].age"/><br/> ognl访问静态属性：<s:property value="@com.cy.common.MyStatic@str"/><br>
<!-- 访问静态方法，有些封装好的Util工具，转换等，就可以直接调用了 -->
ognl访问静态方法：<s:property value="@com.cy.common.MyStatic@print()"/>
</body>
</html>
测试：
---------