JAVAEE学习——struts2_02：结果跳转方式、访问servletAPI方式、获得参数以及封装、练习:添加客户

一、结果跳转方式

        <action name="Demo1Action" class="cn.itheima.a_result.Demo1Action" method="execute" >
            <result name="success" type="dispatcher" >/hello.jsp</result>
        </action>

        <action name="Demo2Action" class="cn.itheima.a_result.Demo2Action" method="execute" >
            <result name="success" type="redirect" >/hello.jsp</result>
        </action>

        <action name="Demo3Action" class="cn.itheima.a_result.Demo3Action" method="execute" >
             <result name="success" type="chain">
                     <!-- action的名字 -->
                 <param name="actionName">Demo1Action</param>
                     <!-- action所在的命名空间 -->
                 <param name="namespace">/</param>
             </result>
        </action>

        <action name="Demo4Action" class="cn.itheima.a_result.Demo4Action" method="execute" >
            <result  name="success"  type="redirectAction">
                 <!-- action的名字 -->
                 <param name="actionName">Demo1Action</param>
                 <!-- action所在的命名空间 -->
                 <param name="namespace">/</param>
            </result>
        </action>

二、访问servletAPI方式

　　1.原理

　　

　　2.通过ActionContext（推荐）

//如何在action中获得原生ServletAPI
public class Demo5Action extends ActionSupport {

    public String execute() throws Exception {
        //request域=> map (struts2并不推荐使用原生request域)
        //不推荐
        Map<String, Object> requestScope = (Map<String, Object>) ActionContext.getContext().get("request");
        //推荐
        ActionContext.getContext().put("name", "requestTom");
        //session域 => map
        Map<String, Object> sessionScope = ActionContext.getContext().getSession();
        sessionScope.put("name", "sessionTom");
        //application域=>map
        Map<String, Object> applicationScope = ActionContext.getContext().getApplication();
        applicationScope.put("name", "applicationTom");
        
        return SUCCESS;
    }    
}

　　3.通过ServletActionContext

//如何在action中获得原生ServletAPI
public class Demo6Action extends ActionSupport {
    //并不推荐
    public String execute() throws Exception {
        //原生request
        HttpServletRequest request = ServletActionContext.getRequest();
        //原生session
        HttpSession session = request.getSession();
        //原生response
        HttpServletResponse response = ServletActionContext.getResponse();
        //原生servletContext
        ServletContext servletContext = ServletActionContext.getServletContext();
        return SUCCESS;
    }
}

　　4.通过实现接口方式

//如何在action中获得原生ServletAPI
public class Demo7Action extends ActionSupport implements ServletRequestAware {
    
    private HttpServletRequest request;

    public String execute() throws Exception { 
        
        System.out.println("原生request:"+request);
        return SUCCESS;
    }

    @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request = request;
    }

}

三、如何获得参数

　　1.扩展

　　　　1.1 strutsMVC

　　　　　　　　

             1.2 Action生命周期

 　　　　　　1.2.1 每次请求到来时,都会创建一个新的Action实例

　　　　　　 1.2.2 Action是线程安全的.可以使用成员变量接收参数

　　2.属性驱动获得参数

    <form action="${pageContext.request.contextPath}/Demo8Action">
        用户名:<input type="text" name="name" /><br>
        年龄:<input type="text" name="age" /><br>
        生日:<input type="text" name="birthday" /><br>
        <input type="submit" value="提交" />
    </form>

    //准备与参数键名称相同的属性
    private String name;
    //自动类型转换 只能转换8大基本数据类型以及对应包装类
    private Integer age;
    //支持特定类型字符串转换为Date ,例如 yyyy-MM-dd
    private Date   birthday;
    

    public String execute() throws Exception { 
        
        System.out.println("name参数值:"+name+",age参数值:"+age+",生日:"+birthday);
        
        return SUCCESS;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name;
    }


    public Integer getAge() {
        return age;
    }


    public void setAge(Integer age) {
        this.age = age;
    }


    public Date getBirthday() {
        return birthday;
    }


    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

　　3.对象驱动

    <form action="${pageContext.request.contextPath}/Demo9Action">
        用户名:<input type="text" name="user.name" /><br>
        年龄:<input type="text" name="user.age" /><br>
        生日:<input type="text" name="user.birthday" /><br>
        <input type="submit" value="提交" />
    </form>

public class Demo9Action extends ActionSupport  {
    //准备user对象
    private User user;

    public String execute() throws Exception { 
        
        System.out.println(user);
        
        return SUCCESS;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }
}

　　4.模型驱动

    <form action="${pageContext.request.contextPath}/Demo10Action">
        用户名:<input type="text" name="name" /><br>
        年龄:<input type="text" name="age" /><br>
        生日:<input type="text" name="birthday" /><br>
        <input type="submit" value="提交" />
    </form>

public class Demo10Action extends ActionSupport implements ModelDriven<User> {
    //准备user 成员变量
    private User user =new User();

    public String execute() throws Exception { 
        
        System.out.println(user);
        
        return SUCCESS;
    }

    @Override
    public User getModel() {
        return user;
    }
}

四、集合类型参数封装

　　1.List和Map

    <form action="${pageContext.request.contextPath}/Demo11Action" method="post" >
        list:<input type="text" name="list" /><br>
        list:<input type="text" name="list[3]" /><br>
        map:<input type="text" name="map['haha']" /><br>
        <input type="submit" value="提交" />
    </form>

public class Demo11Action extends ActionSupport  {
    //list
    private List<String> list;
    //Map
    private Map<String,String> map;
    
    
    public String execute() throws Exception { 
        
        System.out.println("list:"+list);
        System.out.println("map:"+map);
        
        return SUCCESS;
    }

    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;
    }

}

五、练习:添加客户

　　注意:struts和hibernate包在合并时.javassist-3.18.1-GA.jar包是重复的,删除版本低的.

     实现步骤：

　　

public class CustomerAction extends ActionSupport implements ModelDriven<Customer> {
    private CustomerService cs = new CustomerServiceImpl();
    private Customer customer = new Customer();
    
    //添加客户
    public String add() throws Exception {
        //1 调用Service
        cs.save(customer);
        //2 重定向到列表action方法
        return "toList";
    }
}

    <package name="crm" namespace="/" extends="struts-default" >
        <action name="CustomerAction_*" class="cn.itheima.web.action.CustomerAction" method="{1}" >
            <result name="list" >/jsp/customer/list.jsp</result>
            <result name="toList" type="redirectAction">
                 <param name="actionName">CustomerAction_list</param>
                 <param name="namespace">/</param>
             </result>
        </action>
    </package>