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struts2学习(7)值栈简介与OGNL引入
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：
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struts2学习(7)值栈简介与OGNL引入
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