OGNL入门

package org.darkness.ognl.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit.framework.TestCase;
import ognl.Ognl;

import org.darkness.oa.model.Person;
import org.darkness.oa.model.User;

public class OgnlTest extends TestCase {
	
	// ***************** root对象的概念 ******************* //
	public void testOgnl_01() throws Exception{
		User user = new User();
		user.setUsername("暗之幻影");
		
		//相当于调用user.getUsername()方法
		String value = (String)Ognl.getValue("username", user);
		System.out.println(value);
	}
	
	public void testOgnl_02() throws Exception{
		User user = new User();
		Person p = new Person();
		p.setName("暗之幻影");
		user.setPerson(p);
		
		//相当于调用user.getPerson().getName()方法
		String value = (String)Ognl.getValue("person.name", user);
		System.out.println(value);
	}
	
	public void testOgnl_03() throws Exception{
		User user = new User();
		Person p = new Person();
		p.setName("暗之幻影");
		user.setPerson(p);
		
		//可以使用#root来引用根对象，相当于调用user.getPerson().getName()方法
		String value = (String)Ognl.getValue("#root.person.name", user);
		System.out.println(value);
	}
	
	// *********************** context的概念 **********************//
	public void testOgnl_04() throws Exception{
		Person p1 = new Person();
		Person p2 = new Person();
		p1.setName("风");
		p2.setName("云");

		Map<String,Person> context = new HashMap<String,Person>();
		context.put("p1", p1);
		context.put("p2", p2);
		
		// 需要加上#才表示到context中取数据，否则表示从根目录下取值
		String value = (String)Ognl.getValue("#p1.name + ',' + #p2.name", context, new Object());
		System.out.println(value);
	}
	
	public void testOgnl_05() throws Exception{
		Person p1 = new Person();
		Person p2 = new Person();
		p1.setName("风");
		p2.setName("云");
		
		Map<String,Person> context = new HashMap<String,Person>();
		context.put("p1", p1);
		context.put("p2", p2);
		
		User root = new User();
		root.setUsername("雨");
		
		String value = (String)Ognl.getValue("#p1.name + ',' + #p2.name + ',' + username", context, root);
		System.out.println(value);
	}
	
	// ******************* OGNL赋值操作 ************************//
	public void testOgnl_06() throws Exception{
		User user = new User();
		
		//给root对象的属性赋值，相当于调用user.setUsername()
		Ognl.setValue("username", user, "暗之幻影");
		
		System.out.println(user.getUsername());
	}
	
	public void testOgnl_07() throws Exception{
		User user = new User();

		Map<String, User> context = new HashMap<String, User>();
		context.put("u", user);
		
		//给context中的对象属性赋值，相当于调用user.setUsername()
		Ognl.setValue("#u.username", context, new Object(), "暗之幻影");
		
		System.out.println(user.getUsername());
	}
	
	public void testOgnl_08() throws Exception{
		User user = new User();
		
		Map<String, User> context = new HashMap<String, User>();
		context.put("u", user);
		
		//给context中的对象属性赋值，相当于调用user.setUsername()
		//在表达式中使用=赋值操作符来赋值
		Ognl.getValue("#u.username = '暗之幻影'",context, new Object());
		
		System.out.println(user.getUsername());
	}
	
	public void testOgnl_09() throws Exception{
		User user = new User();
		Person p = new Person();
		
		Map<String,Object> context = new HashMap<String,Object>();
		context.put("u", user);
		context.put("p", p);
		
		//给context中的对象属性赋值，相当于调用user.setUsername()
		//在表达式中使用=赋值操作符来赋值
		Ognl.getValue("#u.username = '风',#p.name = '云'",context, new Object());
		
		System.out.println(user.getUsername()+","+p.getName());
	}
	
	//****************** 使用OGNL调用对象的方法 **********************//
	public void testOgnl_10() throws Exception{
		User user = new User();
		user.setUsername("暗之幻影");
		
		String value = (String)Ognl.getValue("getUsername()", user);
		System.out.println(value);
	}
	
	public void testOgnl_11() throws Exception{
		User user = new User();
		
		Ognl.getValue("setUsername('暗之幻影')", user);
		System.out.println(user.getUsername());
	}
	
	// ******************* OGNL调用类变量、静态方法 *************************//
	public void testOgnl_12() throws Exception{
		User user = new User();
		
		Ognl.getValue("setUsername('暗之幻影')", user);
		Ognl.getValue("@[email protected](username)", user);
	}
	
	public void testOgnl_13() throws Exception{
		User user = new User();
		
		Ognl.getValue("setUsername('暗之幻影')", user);
		Ognl.getValue("@[email protected](@org.darkness.struts2.test.Utils@toLowerCase(username))", user);
	}
	
	// ********************* OGNL中的this表达式 **********************//
	public void testOgnl_14() throws Exception{
		Object root = new Object();
		Map context = new HashMap();
		
		List values = new ArrayList();
		for(int i=0; i<11; i++){
			values.add(i);
		}
		context.put("values", values);
		
		Ognl.getValue("@[email protected](#values.size.(#this > 10 ? \"大于10\" : '不大于10'))", context, root);
		
	}
	
	public void testOgnl_15() throws Exception{
		User user = new User();
		
		Ognl.getValue("setUsername('暗之幻影')", user);
		Ognl.getValue("@[email protected](#this.username)", user);
	}
	
	public void testOgnl_16() throws Exception{
		User user = new User();
		
		Ognl.getValue("setUsername('暗之幻影')", user);
		Ognl.getValue("@[email protected](username.(#this.toLowerCase()))", user);
	}
	
	// ******************* 如何把表达式的解释结果作为另外一个表达式,OGNL中括号的使用 **********************//
	public void testOgnl_17() throws Exception{
		Object root = new Object();
		Map context = new HashMap();
		User u = new User();
		u.setUsername("暗之幻影");
		context.put("u", u);
		context.put("fact", "username");
		
		/**
		 * 1、首先把#fact表达式进行解释，得到一个值：username
		 * 2、解释括号中的表达式#u，其结果是user对象
		 * 3、把括号中表达式的结果作为root对象，解释在第一步中得到的结果（即把第一步的结果看成另外一个表达式） 
		 */
		String value = (String)Ognl.getValue("#fact(#u)", context, root);
		System.out.println(value);
	}
	
	public void testOgnl_18() throws Exception{
		Person person = new Person();
		Map context = new HashMap();
		User u = new User();
		u.setUsername("暗之幻影");
		context.put("u", u);
		
		/**
		 * 相当于调用person这个根对象的fact方法，并把#u的解释结果作为参数传入此方法 
		 */
		String value = (String)Ognl.getValue("fact(#u)", context, person);
		System.out.println(value); //输出是 "暗之幻影,"
	}
	
	public void testOgnl_19() throws Exception{
		Person person = new Person();
		Map context = new HashMap();
		User u = new User();
		u.setUsername("暗之幻影");
		context.put("u", u);
		
		/**
		 * 1、先计算表达式fact，得到结果是：username
		 * 2、解释括号中的表达式#u，其结果是user对象
		 * 3、把括号中表达式的结果作为root对象，解释在第一步中得到的结果（即把第一步的结果看成另外一个表达式）
		 */
		String value = (String)Ognl.getValue("(fact)(#u)", context, person);
		System.out.println(value); //输出"暗之幻影"
	}
	
	// ********************* OGNL访问集合元素 **************************//
	public void testOgnl_20() throws Exception{
		Object root = new Object();
		Map context = new HashMap();
		
		//用OGNL创建List对象
		List listvalue = (List)Ognl.getValue("{123,'暗之幻影','风之水影'}", context, root);
		context.put("listvalue", listvalue);
		
		//用OGNL创建数组
		int[] intarray= (int[])Ognl.getValue("new int[]{23,45,67}", context, root);
		context.put("intarray", intarray);
		
		//用OGNL创建Map对象
		Map mapvalue = (Map)Ognl.getValue("#{'listvalue':#listvalue,'intarray':#intarray}", context, root);
		context.put("mapvalue", mapvalue);
		
		Ognl.getValue("@[email protected](#listvalue[0])", context, root);
		Ognl.getValue("@[email protected](#intarray[1])", context, root);
		Ognl.getValue("@[email protected](#mapvalue['intarray'][2])", context, root);
		Ognl.getValue("@[email protected](#mapvalue.intarray[0])", context, root);
	}
}