Structs2 ognl说明

下面是struts.xml中的配置

<constant name="struts.enable.DynamicMethodInvocation" value="false"/>

<constant name="struts.devMode" value="true"/>

<constant name="struts.ognl.allowStaticMethodAccess" value="true"/>

<include file="/com/java/login/struts2/action/ognl.xml"/>

以下是ognl.xml的配置

OGNL使用介绍:

<%@ taglib uri="/struts-tags" prefix="s" %>

<body>
<ol>
<li>访问值栈中的action的普通属性:　userName= <s:property value="userName" /></li>
<li>访问值栈中对象的普通属性(get set方法):　<s:property value="user.age" /></li>
<li>什么叫OGNL:Object Graph Navigation Language -对象图导航语言</li>
<li>访问值栈中对象的普通属性:　<s:property value="cat.friend.name"/></li>
<li>访问值栈中对象的普通方法:　<s:property value="password.length()"/></li>
<li>访问值栈中对象的普通方法:　<s:property value="cat.miaomiao()"/></li>
<li>访问值栈中action的普通方法:　<s:property value="method()"/></li>
<hr/>
<li>访问静态方法:　<s:property value="@com.java.login.struts2.action.Test@getValue()"/></li>
<li>访问静态属性: <s:property value="@com.java.login.struts2.action.Test@STR"/></li>

<li>访问Math类的静态方法: <s:property value="@@max(2,3)"/></li>
<hr/>
<li>访问普通类的构造方法:　<s:property value="new com.java.login.struts2.pojo.User()" /></li>
<hr/>
<li>访问List: <s:property value="users"/> </li>
<li>访问List中某个元素: <s:property value="users[1]"/></li>
<li>访问List中元素某个属性的集合: <s:property value="users.{age}"/></li>
<li>访问List中元素某个属性的集合中的特定值: <s:property value="users.{age}[0]"/></li>
<hr/>
<li>访问Set:　<s:property value="dogs"/></li>
<li>访问Set中某个元素:　<s:property value="dogs[1]"/></li>
<hr/>
<li>访问Map: <s:property value="dogMap"/></li>
<li>访问Map中某个元素: <s:property value="dogMap.dog101"/> | <s:property value="dogMap['dog102']"/> | </li>
<li>访问Map中所有的Key: <s:property value="dogMap.keys"/></li>
<li>访问Map中所有的Value: <s:property value="dogMap.values"/></li>
<li>访问容器的大小: <s:property value="dogMap.size()"/></li>
<hr>
<li>投影(过滤): <s:property value="users.{?#this.age==1}[0]"/></li>
<li>投影(^开始的那个): <s:property value="users.{^#this.age>1}.{age}"/></li>
<li>投影($结尾的那个): <s:property value="users.{$#this.age>1}.{age}"/></li>
<li>投影(判断): <s:property value="users.{$#this.age>1}.{age}==null"/></li>
<hr>
<li>[]:<s:property value="[0]"/></li>
</ol>
<s:debug></s:debug>
</body>

上边与Action交互的类:

public class OgnlAction extends ActionSupport {

private static final long serialVersionUID = 1L;

private Cat cat;

private Map<String, Dog> dogMap = new HashMap<String, Dog>();

private Set<Dog> dogs = new HashSet<Dog>();

// 成员变量
private String password;

// 实体对象
private User user;

private String userName;

private List<User> users = new ArrayList<User>();

public OgnlAction() {
  users.add(new User(1));
  users.add(new User(11));
  users.add(new User(12));
  users.add(new User(13));

  dogs.add(new Dog("dog1"));
  dogs.add(new Dog("dog2"));
  dogs.add(new Dog("dog3"));

  dogMap.put("dog100", new Dog("dog100"));
  dogMap.put("dog101", new Dog("dog101"));
  dogMap.put("dog102", new Dog("dog102"));
}

@Override
public String execute() throws Exception {
return "success";
}

public Cat getCat() {
return cat;
}

public Map<String, Dog> getDogMap() {
return dogMap;
}

public Set<Dog> getDogs() {
return dogs;
}

public String getPassword() {
return password;
}

public User getUser() {
return user;
}

public String getUserName() {
return userName;
}

public List<User> getUsers() {
return users;
}

public String method() {
return "Hello";
}

public void setCat(Cat cat) {
this.cat = cat;
}

public void setDogMap(Map<String, Dog> dogMap) {
this.dogMap = dogMap;
}

public void setDogs(Set<Dog> dogs) {
this.dogs = dogs;
}

public void setPassword(String password) {
this.password = password;
}

public void setUser(User user) {
this.user = user;
}

public void setUserName(String userName) {
this.userName = userName;
user.setUserName(userName);
}

public void setUsers(List<User> users) {
this.users = users;
}
}