Spring IOC 實現用戶登錄驗證機制

架構設計

• Model：User 實體類
• Controller：TestUtil 繼承 AbstractController
• 配置：applicationContext.xml 定義 Bean 並自動裝配

1. 實體類 User

public class User {
    private String username, password;
    // getter/setter 省略
}

2. 控制器 TestUtil

public class TestUtil extends AbstractController {
    private User user;
    public void setUser(User user) { this.user = user; }

    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest req, HttpServletResponse resp) {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        if (username.equals(user.getUsername()) && password.equals(user.getPassword())) {
            return new ModelAndView("yes");
        }
        return new ModelAndView("Error");
    }
}

3. Spring 配置 applicationContext.xml

<beans>
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <bean id="user" class="com.importnew.User">
        <property name="username" value="admin"/>
        <property name="password" value="123"/>
    </bean>

    <bean id="testUtil" class="com.importnew.TestUtil" autowire="byName">
        <property name="user" ref="user"/>
    </bean>
</beans>

4. web.xml 配置 DispatcherServlet

<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/applicationContext.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

運行流程

1. 啟動項目，Spring 容器讀取配置，實例化 user 並注入 testUtil
2. 用戶訪問 /login.do?username=admin&password=123
3. DispatcherServlet 分發到 TestUtil，驗證通過轉向 yes.jsp，失敗轉向 Error.jsp

依賴提示

需引入 spring-webmvc JAR 以支持 AbstractController。