Action 类通过可以实现某些特定的接口, 让 Struts2 框架在运行时向 Action 实例注入 parameters, request, session 和 application 对应的 Map 对象

public class TestAwareAction implements ApplicationAware, SessionAware, RequestAware,

    ParameterAware{

    public String execute(){

        //1. 向 application 中加入一个属性: applicationKey2 - applicationValue2

        application.put("applicationKey2", "applicationValue2");

        //2. 从 application 中读取一个属性 date, 并打印.

        System.out.println(application.get("date"));

        return "success";

    }

    public String save(){

        return null;

    }

    private Map<String, Object> application;

    @Override

    public void setApplication(Map<String, Object> application) {

        this.application = application;

    }

    @Override

    public void setParameters(Map<String, String[]> parameters) {

    }

    @Override

    public void setRequest(Map<String, Object> request) {

        // TODO Auto-generated method stub

    }

    @Override

    public void setSession(Map<String, Object> session) {

        // TODO Auto-generated method stub

    }

}