struts OGNL表达式-白红宇

struts OGNL表达式

阅读量：5856 次

发布时间：2019-06-19

本文共 4699 字，大约阅读时间需要 15 分钟。

OGNLContext对象有两部分构成

　　一部分是ROOT：可以放置任何对象作为ROOT

　　另外一部分Context：必须是Map形式（键值对）

OGNL表达式操作

package cn.future.a_ognl;import java.util.HashMap;import java.util.Map;import ognl.Ognl;import ognl.OgnlContext;import ognl.OgnlException;import org.junit.Test;import cn.future.domain.User;public class Demo {        @Test    //取出Root中的值    public void fun() throws OgnlException{        //OGNL表达式        //准备ROOT        User userRoot = new User("ms",25);        //准备Context        Map
     
       contextMap = new HashMap
      
       ();        contextMap.put("user1", new User("AAA",10));        contextMap.put("user2", new User("BBB",11));        //书写OGNL        OgnlContext oc = new OgnlContext();        oc.setRoot(userRoot);        oc.setValues(contextMap);        //OGNL取值        //取root中userRoot对象的name属性        String name = (String) Ognl.getValue("name", oc, oc.getRoot());        int age = (Integer) Ognl.getValue("age", oc, oc.getRoot());        System.out.println(name);        System.out.println(age);    }        @Test    //取出Context中的值    public void fun1() throws OgnlException{        //OGNL表达式        //准备ROOT        User userRoot = new User("ms",25);        //准备Context        Map
       
         contextMap = new HashMap
        
         ();        contextMap.put("user1", new User("AAA",10));        contextMap.put("user2", new User("BBB",11));        //书写OGNL        OgnlContext oc = new OgnlContext();        oc.setRoot(userRoot);        oc.setValues(contextMap);        //OGNL取值        //取User1对象的name属性        String name = (String) Ognl.getValue("#user1.name", oc, oc.getRoot());        int age = (Integer) Ognl.getValue("#user1.age", oc, oc.getRoot());        System.out.println(name);        System.out.println(age);    }        @Test    //为属性赋值    public void fun2() throws OgnlException{        //OGNL表达式        //准备ROOT        User userRoot = new User("ms",25);        //准备Context        Map
         
           contextMap = new HashMap
          
           (); contextMap.put("user1", new User("AAA",10)); contextMap.put("user2", new User("BBB",11)); //书写OGNL OgnlContext oc = new OgnlContext(); oc.setRoot(userRoot); oc.setValues(contextMap); //OGNL取值 //给Roog中userRoot对象的name属性赋值 Ognl.getValue("name='grf'", oc, oc.getRoot());//赋值 有返回值，返回值是name的值 String name = (String) Ognl.getValue("name='grf',name", oc, oc.getRoot());//即赋值又取值 //给Context中user1的name属性赋值 Ognl.getValue("#user1.name='grf'", oc, oc.getRoot()); } @Test //为属性赋值(set get) public void fun3() throws OgnlException{ //OGNL表达式 //准备ROOT User userRoot = new User("ms",25); //准备Context Map
           
             contextMap = new HashMap
            
             (); contextMap.put("user1", new User("AAA",10)); contextMap.put("user2", new User("BBB",11)); //书写OGNL OgnlContext oc = new OgnlContext(); oc.setRoot(userRoot); oc.setValues(contextMap); //OGNL取值 //给Roog中userRoot对象的name属性赋值 Ognl.getValue("setName('grf')", oc, oc.getRoot());//赋值 返回值为null String name = (String) Ognl.getValue("getName()", oc, oc.getRoot());//即赋值又取值 //给Context中user1的name属性赋值 Ognl.getValue("#user1.setName('grf'),#user1.getName()", oc, oc.getRoot()); } @Test //调用静态方法，或者静态属性 public void fun4() throws OgnlException{ //OGNL表达式 //准备ROOT User userRoot = new User("ms",25); //准备Context Map
             
               contextMap = new HashMap
              
               (); contextMap.put("user1", new User("AAA",10)); contextMap.put("user2", new User("BBB",11)); //书写OGNL OgnlContext oc = new OgnlContext(); oc.setRoot(userRoot); oc.setValues(contextMap); //OGNL取值 //给Roog中userRoot对象的name属性赋值 Double pi = (Double) Ognl.getValue("@java.lang.Math@PI", oc, oc.getRoot());//赋值 返回值为null System.out.println(pi); } @Test //创建集合 list|map public void fun5() throws OgnlException{ //OGNL表达式 //准备ROOT User userRoot = new User("ms",25); //准备Context Map
               
                 contextMap = new HashMap
                
                 (); contextMap.put("user1", new User("AAA",10)); contextMap.put("user2", new User("BBB",11)); //书写OGNL OgnlContext oc = new OgnlContext(); oc.setRoot(userRoot); oc.setValues(contextMap); //OGNL取值 //创建list Ognl.getValue("{'aaa','bbb','ccc','ddd'}", oc, oc.getRoot()); Integer listSize = (Integer) Ognl.getValue("{'aaa','bbb','ccc','ddd'}.size()", oc, oc.getRoot()); String listName = (String) Ognl.getValue("{'aaa','bbb','ccc','ddd'}[0]", oc, oc.getRoot()); String listName1 = (String) Ognl.getValue("{'aaa','bbb','ccc','ddd'}.get(1)", oc, oc.getRoot()); //创建map Ognl.getValue("#{'name':'ms','age',25}", oc, oc.getRoot()); Integer mapSize = (Integer) Ognl.getValue("#{'name':'ms','age',25}.size()", oc, oc.getRoot()); String mapName = (String) Ognl.getValue("#{'name':'ms','age',25}[name]", oc, oc.getRoot()); Integer mapAge = (Integer) Ognl.getValue("#{'name':'ms','age',25}.get('age')", oc, oc.getRoot()); }}