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package com.lxy.test;

import ognl.OgnlContext;
import ognl.OgnlException;

public class Demo1 {
    /**
     * @param args
     * @throws OgnlException
     */
    public static void main(String[] args)  {
        Employee e = new Employee();
        e.setName("小李");

        Manager m = new Manager();
        m.setName("张经理");

        // 创建OGNL下文,而OGNL上下文实际上就是一个Map对象
        OgnlContext ctx = new OgnlContext();

        // 将员工和经理放到OGNL上下文当中去
        ctx.put("employee", e);
        ctx.put("manager", m);
        ctx.setRoot(e);// 设置OGNL上下文的根对象

        /** ********************** 取值操作 *************************** */
        // 表达式name将执行e.getName()，因为e对象是根对象(请注意根对象和非根对象表达式的区别)
        String employeeName = (String) OnglExpression.getValue("name", ctx, e);
        System.out.println(employeeName);

        // 表达式#manager.name将执行m.getName()，注意：如果访问的不是根对象那么必须在前面加上一个名称空间，例如：#manager.name
        String managerName = (String) OnglExpression.getValue("#manager.name",
                ctx, e);
        System.out.println(managerName);

        // 当然根对象也可以使用#employee.name表达式进行访问
        employeeName = (String) OnglExpression.getValue("#employee.name", ctx,
                e);
        System.out.println(employeeName);

        /** ********************** 赋值操作 *************************** */
        OnglExpression.setValue("name", ctx, e, "小明");
        employeeName = (String) OnglExpression.getValue("name", ctx, e);
        System.out.println(employeeName);

        OnglExpression.setValue("#manager.name", ctx, e, "孙经理");
        managerName = (String) OnglExpression.getValue("#manager.name", ctx, e);
        System.out.println(managerName);

        OnglExpression.setValue("#employee.name", ctx, e, "小芳");
        employeeName = (String) OnglExpression.getValue("name", ctx, e);
        System.out.println(employeeName);
    }

}

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package com.lxy.test;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.util.ValueStack;

public class Demo7 extends ActionSupport{
    /**
     * 
     * 值栈的使用
     * 
     */
    public String ognl1() {
        // 栈：表示一个先进后出的数据结构
        ValueStack vs = ActionContext.getContext().getValueStack();
        // push方法把项压入栈顶
        vs.push(new Employee("zs", 22));
        vs.push(new Employee("ls", 22));
        vs.push(new Employee("ww", 22));

        // pop方法移除栈顶对象并作为此函数的值返回该对象
        Employee e = (Employee) vs.pop();
        System.out.println(e.getName());
        e = (Employee) vs.pop();
        System.out.println(e.getName());
        e = (Employee) vs.pop();
        System.out.println(e.getName());
        return "bookEdit";
    }

    /**
     * 此例用于模拟struts2的值栈计算过程
     * 
     * @param args
     */
    public String ognl2() {
        ValueStack vs = ActionContext.getContext().getValueStack();
        vs.push(new Employee("张雇员", 2000));// 1
        vs.push(new Student("小明同学", "s001"));// 0
        System.out.println(vs.findValue("name"));
        System.out.println(vs.findValue("salary2"));
        ActionContext ac = ActionContext.getContext();
        return "bookEdit";
    }
}