Spring MVC 頁面跳轉方式全總結：原生 API、ModelAndView、ModelMap 與 重導向/轉發語法

基礎配置

<!-- web.xml -->
<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<!-- dispatcher-servlet.xml -->
<context:component-scan base-package="com.xxx" />
<!-- 視圖解析器 (有無影響跳轉寫法) -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    <property name="prefix" value="/WEB-INF/jsp/"/>
    <property name="suffix" value=".jsp"/>
</bean>

1. 原生 Servlet API 方式

1.1 直接輸出響應

@RequestMapping("/resp")
public void handle(HttpServletRequest req, HttpServletResponse resp) throws Exception {
    resp.getWriter().println("hello HttpServletResponse");
}

1.2 sendRedirect 重導向

@RequestMapping("/resp")
public void handle(HttpServletRequest req, HttpServletResponse resp) throws Exception {
    resp.sendRedirect("index.jsp"); // 瀏覽器 URL 變化
}

1.3 forward 轉發

@RequestMapping("/resp")
public void handle(HttpServletRequest req, HttpServletResponse resp) throws Exception {
    req.setAttribute("message", "it's forward");
    req.getRequestDispatcher("index.jsp").forward(req, resp); // URL 不變
}

2. 返回 String 視圖名 (有/無視圖解析器)

3. ModelAndView 方式 (需視圖解析器)

@Controller
public class HelloController implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse resp) {
        ModelAndView mv = new ModelAndView();
        mv.addObject("msg", "hello myfirst mvc"); // 模型數據
        mv.setViewName("hello");                  // 視圖名 → /WEB-INF/jsp/hello.jsp
        return mv;
    }
}

4. ModelMap / Model 方式 (現代推薦)

@RequestMapping("/modelmap")
public String modelHello(String name, ModelMap map) {
    map.addAttribute("name", name);
    return "index.jsp"; // 無視圖解析器時寫全名；有解析器寫邏輯名
}

也可用 Model、@ModelAttribute 綁定表單對象。

核心差異總結

關鍵前綴語法

• forward:viewName → RequestDispatcher.forward()
• redirect:viewName → HttpServletResponse.sendRedirect()
• 有視圖解析器時，viewName 為邏輯名；無解析器時為物理路徑