Struts2的OGNL经典实例

来源：互联网发布：大数据培训机构排名编辑：程序博客网时间：2024/05/29 15:16

OGNL：对象图导航语言，是一种功能强大的表达式语言，它通过简单一致的语法，不但可以任意存取对象的属性还可以调用对象的方法，能够遍历整个对象的结构图，实现对象属性类型的转换等功能。

之前写过一篇博客：http://blog.csdn.net/tjcyjd/article/details/6850203，在此不多研究了，贴出一个OGNL实例，比较全面，比较经典，分享一下。

先看看Jsp页面ognl_info.jsp：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%@ taglib uri="/struts-tags" prefix="s" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>OGNL的使用</title>  </head>  <body><h3>OGNL的使用</h3><hr/> 访问Action中的普通属性: <s:property value="loginname"/><br/> 访问Action中的对象属性: <s:property value="user.birthday"/><br/> 访问Action中的Set属性: <s:property value="courseSet.toArray()[0]"/><br/> 访问Action中的List属性: <s:property value="list[0]"/><br/> 访问Action中的Map属性的键: <s:property value="map.keys.toArray()[1]"/><br/> 访问Action中的Map属性的值: <s:property value="map.values.toArray()[1]"/><br/>访问Action中的Map属性的指定键对应的值: <s:property value="map['z']"/><br/> 访问Action中的Map属性的大小: <s:property value="map.size"/><br/> <hr/>访问ActionContext中的普通属性：<s:property value="#inte"/><br/>访问ActionContext中的对象属性：<s:property value="#user2.loginname"/><br/><hr/>访问Action中的普通方法：<s:property value="getAppName()"/><br/>访问ActionContext中的某个对象上的普通方法：<s:property value="#user2.info()"/><br/><hr/>访问静态属性：<s:property value="@java.lang.Math@PI"/><br/>访问静态方法：<s:property value="@java.lang.Math@floor(44.56)"/><br/>访问Math类中的静态方法：<s:property value="@@floor(44.56)"/><br/><hr/>调用java.util.Date的构造方法：<s:date name="new java.util.Date()" format="yyyy-MM-dd HH:mm:ss"/><br/>调用java.util.Date的构造方法创建对象，再调用它的方法：<s:property value="new java.util.Date().getTime()"/><br/><hr/>投影查询：获取userList中所有loginname的列表:<s:property value="userList.{loginname}"/><br/>选择查询：获取userList中所有score大于60的loginname列表：<s:property value="userList.{?#this.score>60.0}.{loginname}"/><br/>选择查询：获取userList中所有score大于60并且gender为true的loginname列表：<s:property value="userList.{?(#this.score>60.0 && #this.gender)}.{loginname}"/><br/>选择查询：获取userList中所有score大于60并且gender为true的第一个元素的loginname：<s:property value="userList.{^(#this.score>60.0 && #this.gender)}.{loginname}"/><br/>选择查询：获取userList中所有score大于60并且gender为true的最后一个元素的loginname：<s:property value="userList.{$(#this.score>60.0 && #this.gender)}.{loginname}"/><br/><hr/>访问名为xxx的请求参数对应的第一个值：<s:property value="#parameters.xxx[0]"/><br/>访问通过ActionContext中放入Request中的属性：<s:property value="#request.reqAtt"/><br/>访问通过ServletActionContext中放入Request中的属性：<s:property value="#request.reqAtt2"/><br/>访问通过ActionContext中放入Session中的属性：<s:property value="#session.sesAtt"/><br/>访问通过ServletActionContext中放入Session中的属性：<s:property value="#session.sesAtt2"/><br/>访问通过ActionContext中放入ServletContext中的属性：<s:property value="#application.appAtt"/><br/>访问通过ServletActionContext中放入ServletContext中的属性：<s:property value="#application.appAtt2"/><br/>直接访问属性域中指定名称的属性对应的值：<s:property value="#attr.sesAtt2"/><br/><br/><br/><hr/><s:iterator value="userList" status="vs"><s:if test="%{#vs.odd}"><span style="color: red"><s:property value="#vs.index"/>: <s:property value="loginname"/>,<s:date name="birthday" format="yyyy-MM-dd HH:mm:ss"/><br/></span></s:if><s:else><span style="color: blue"><s:property value="#vs.index"/>: <s:property value="loginname"/>,<s:date name="birthday" format="yyyy-MM-dd HH:mm:ss"/><br/></span></s:else></s:iterator><hr/><s:debug/>  </body></html>

User实体类User.java:

package com.tjcyjd.web.action;import java.util.Date;/** * 实体类 *  *  */public class User {private Integer id;private String loginname;private Double score;private Boolean gender;private Character cha;private Date birthday;public User() {}public User(Integer id, String loginname, Double score, Boolean gender,Character cha, Date birthday) {this.id = id;this.loginname = loginname;this.score = score;this.gender = gender;this.cha = cha;this.birthday = birthday;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getLoginname() {return loginname;}public void setLoginname(String loginname) {this.loginname = loginname;}public Double getScore() {return score;}public void setScore(Double score) {this.score = score;}public Boolean getGender() {return gender;}public void setGender(Boolean gender) {this.gender = gender;}public Character getCha() {return cha;}public void setCha(Character cha) {this.cha = cha;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public String info() {return "User [birthday=" + birthday + ", cha=" + cha + ", gender="+ gender + ", id=" + id + ", loginname=" + loginname+ ", score=" + score + "]";}}

Action类OGNLAction:

package com.tjcyjd.web.action;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.LinkedHashSet;import java.util.List;import java.util.Map;import java.util.Set;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;/** * OGNL Action类 *  */public class OGNLAction extends ActionSupport {private static final long serialVersionUID = -2554018432709689579L;private String loginname;private String pwd;private User user;private Set<String> courseSet;private List<String> list;private Map<String, String> map;private List<User> userList;public String execute() throws Exception {this.loginname = "李晓红";this.user = new User(123, "柳梦璃", 88.9, true, 'B', new Date());this.courseSet = new LinkedHashSet<String>();this.courseSet.add("corejava");this.courseSet.add("JSP/Servlet");this.courseSet.add("S2SH");this.list = new ArrayList<String>(this.courseSet);this.map = new HashMap<String, String>();this.map.put("x", "xxx");this.map.put("y", "yyy");this.map.put("z", "zzz");ActionContext context = ActionContext.getContext();context.put("uname", "云天河");context.put("inte", Integer.valueOf(888888));context.put("user2",new User(123, "韩菱纱", 99.1, false, 'B', new Date()));this.userList = new ArrayList<User>();this.userList.add(new User(1, "zs", 48.9, true, 'D', new Date()));this.userList.add(new User(2, "ls", 68.1, true, 'C', new Date()));this.userList.add(new User(3, "ww", 78.2, false, 'B', new Date()));this.userList.add(new User(4, "zl", 88.3, true, 'A', new Date()));// -----------------------------------------------------------------// 推荐方式:不会跟Servlet API耦合context.put("reqAtt", "往ActionContext中put的属性");context.getSession().put("sesAtt", "往ActionContext.getSession()中put的属性");context.getApplication().put("appAtt","往ActionContext.getApplication()中put的属性");ServletActionContext.getRequest().setAttribute("reqAtt2","Request作用域中的属性");ServletActionContext.getRequest().getSession().setAttribute("sesAtt2","Session作用域中的属性");ServletActionContext.getServletContext().setAttribute("appAtt2","Application作用域中的属性");return SUCCESS;}public String getAppName() {return "这是OGNL的使用示例代码";}public String getLoginname() {return loginname;}public void setLoginname(String loginname) {this.loginname = loginname;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public User getUser() {return user;}public void setUser(User user) {this.user = user;}public Set<String> getCourseSet() {return courseSet;}public void setCourseSet(Set<String> courseSet) {this.courseSet = courseSet;}public List<String> getList() {return list;}public void setList(List<String> list) {this.list = list;}public Map<String, String> getMap() {return map;}public void setMap(Map<String, String> map) {this.map = map;}public List<User> getUserList() {return userList;}public void setUserList(List<User> userList) {this.userList = userList;}}