Struts2进阶学习3
OGNL表达式与Struts2的整合
核心配置文件与页面
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<struts> <package name="show" namespace="/" extends="struts-default" >
<action name="ShowAction" class="com.struts2.action.ShowAction" method="execute" >
<result name="success" type="dispatcher" >/show.jsp</result>
</action> <action name="ShowAction2" class="com.struts2.action.ShowAction" method="getParam" >
<result name="success" type="dispatcher" >/form.jsp</result>
</action> <action name="redirect" class="com.struts2.action.RedirectAction" method="redirect" >
<result name="success" type="redirectAction" >
<param name="namespace">/</param>
<param name="actionName">ShowAction</param>
<!-- 路径携带参数;以及利用OGNL表达式动态绑定参数 -->
<param name="name">${name}</param>
</result>
</action>
</package> </struts>
struts.xml
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/ShowAction">
name:<input type="text" name="name"/><br>
<input type="submit" value="提交"/>
</form>
</body>
</html>
form
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<s:debug></s:debug>
</body>
</html>
show
package com.struts2.pojo; /**
* @author: 肖德子裕
* @date: 2018/11/20 21:05
* @description:
*/
public class User {
private String name;
private Integer age; /**
* 回音方法：传什么值返回什么值，一般用于测试
* @param o
* @return
*/
public static Object test(Object o){
return o;
} public User() {
} public User(String name, Integer age) {
this.name = name;
this.age = age;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public Integer getAge() {
return age;
} public void setAge(Integer age) {
this.age = age;
}
}
User
OGNL表达式基本语法
package com.struts2.ognl; import com.struts2.pojo.User;
import ognl.Ognl;
import ognl.OgnlContext;
import org.junit.Test; import java.util.HashMap;
import java.util.Map; /**
* @author: 肖德子裕
* @date: 2018/11/20 21:03
* @description: 测试OGNL表达式(对象视图导航语言)，支持比EL表达式更丰富的语法
*/
public class Demo {
/**
* OGNL基本语法
* @throws Exception
*/
@Test
public void test() throws Exception{
//准备Root（可放置任意对象）
User rootUser=new User("xdzy",18);
//准备Context（放置map）
Map<String,User> context=new HashMap<String,User>();
context.put("user1",new User("jack",17));
context.put("user2",new User("rose",27));
//准备OGNLContext
OgnlContext oc=new OgnlContext();
oc.setRoot(rootUser);
oc.setValues(context); //书写OGNL
//获取rootUser的name和age(第一个参数就是OGNL的语法)
String rootName = (String) Ognl.getValue("name", oc, oc.getRoot());
Integer age = (Integer) Ognl.getValue("age", oc, oc.getRoot());
System.out.println(rootName);
System.out.println(age); //获取context的name与age
String name = (String) Ognl.getValue("#user1.name", oc, oc.getRoot());
System.out.println(name); //对rootUser属性进行赋值
String rootName1 = (String) Ognl.getValue("name='张三'", oc, oc.getRoot());
System.out.println(rootName1); //对context属性进行赋值
String name1 = (String) Ognl.getValue("#user1.name='李四'", oc, oc.getRoot());
System.out.println(name1); //调用rootUser的属性方法
Ognl.getValue("setName('王五')", oc, oc.getRoot());
String rootName2 = (String) Ognl.getValue("getName()", oc, oc.getRoot());
System.out.println(rootName2); //调用context的属性方法
String name2 = (String) Ognl.getValue("#user1.setName('赵六'),#user1.getName()", oc, oc.getRoot());
System.out.println(name2); //调用静态方法;访问静态属性
String name3 = (String) Ognl.getValue("@com.struts2.pojo.User@test('hello')", oc, oc.getRoot());
Double pi = (Double) Ognl.getValue("@java.lang.Math@PI", oc, oc.getRoot());
System.out.println(name3);
System.out.println(pi);
} /**
* OGNL基本语法2
* @throws Exception
*/
@Test
public void test2() throws Exception{
//准备Root（可放置任意对象）
User rootUser=new User("xdzy",18);
//准备Context（放置map）
Map<String,User> context=new HashMap<String,User>();
context.put("user1",new User("jack",17));
context.put("user2",new User("rose",27));
//准备OGNLContext
OgnlContext oc=new OgnlContext();
oc.setRoot(rootUser);
oc.setValues(context); //书写OGNL
//通过OGNL创建list
Integer size = (Integer) Ognl.getValue("{'肖','德','子','裕'}.size()", oc, oc.getRoot());
System.out.println(size);
//通过OGNL创建map
Integer size1 = (Integer) Ognl.getValue("#{'name':'xdzy','age':12}.size()", oc, oc.getRoot());
String name = (String) Ognl.getValue("#{'name':'xdzy','age':12}['name']", oc, oc.getRoot());
Integer age = (Integer) Ognl.getValue("#{'name':'xdzy','age':12}.get('age')", oc, oc.getRoot());
System.out.println(size1);
System.out.println(name);
System.out.println(age);
}
}
Demo
测试整合使用
package com.struts2.action; import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;
import com.opensymphony.xwork2.util.ValueStack;
import com.struts2.pojo.User; /**
* @author: 肖德子裕
* @date: 2018/11/21 9:40
* @description: 测试OGNL表达式与struts2结合
* OGNL表达式的root在struts2中为栈,栈中保存的是当前访问的action
* 队列：先进先出；栈：先进后出(list)
* OGNL表达式的root在struts2中为ActionContext
* implements Preparable：在参数赋值之前实现
*/
public class ShowAction extends ActionSupport implements ModelDriven<User> {
/**
* 重写默认方法
* @return
* @throws Exception
*/
@Override
public String execute() throws Exception {
System.out.println("hello action");
return SUCCESS;
} private User user=new User(); /**
* 如果在参数赋值之前压栈，将无法获取参数值
* @return
*/
public String getParam(){
System.out.println(user);
return SUCCESS;
} /**
* 该拦截器在参数赋值之前实现，所以可以获取参数值
* @throws Exception
*/
/*@Override
public void prepare() throws Exception {
//获取值栈
ValueStack stack = ActionContext.getContext().getValueStack();
//压入栈顶
stack.push(user);
}*/ @Override
public User getModel() {
return user;
}
}
ShowAction
package com.struts2.action; import com.opensymphony.xwork2.ActionSupport; /**
* @author: 肖德子裕
* @date: 2018/11/21 10:40
* @description: 重定向时携带参数
*/
public class RedirectAction extends ActionSupport {
private String name; public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String redirect(){
name="xdzy";
return SUCCESS;
}
}
RedirectAction