SpringMVC方法返回值多种情况代码实例

@Controller
@RequestMapping("/user")
public class HelloController {
  @RequestMapping("/hello")
  public ModelAndView hello() {
    ModelAndView mv = new ModelAndView("hello");
    mv.addObject("username", "javaboy");
    return mv;
  }
}

<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>javax.servlet-api</artifactId>
  <version>4.0.1</version>
</dependency>

@RequestMapping("/hello2")
public void hello2(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  req.getRequestDispatcher("/jsp/hello.jsp").forward(req,resp);//服务器端跳转
}

@RequestMapping("/hello2")
public void hello2(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  req.getRequestDispatcher("/jsp/hello.jsp").forward(req,resp);//服务器端跳转
}

@RequestMapping("/hello3")
public void hello3(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  resp.sendRedirect("/hello.jsp");
}

@RequestMapping("/hello3")
public void hello3(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  resp.setStatus(302);
  resp.addHeader("Location", "/jsp/hello.jsp");
}

@RequestMapping("/hello4")
public void hello4(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  resp.setContentType("text/html;charset=utf-8");
  PrintWriter out = resp.getWriter();
  out.write("hello javaboy!");
  out.flush();
  out.close();
}

@RequestMapping("/hello5")
public String hello5(Model model) {
  model.addAttribute("username", "javaboy");//这是数据模型
  return "hello";//表示去查找一个名为 hello 的视图
}

@RequestMapping("/hello5")
public String hello5() {
  return "forward:/jsp/hello.jsp";
}

@RequestMapping("/hello5")
public String hello5() {
  return "redirect:/user/hello";
}

@RequestMapping("/hello5")
@ResponseBody
public String hello5() {
  return "redirect:/user/hello";
}

@RequestMapping(value = "/hello5",produces = "text/html;charset=utf-8")
@ResponseBody
public String hello5() {
  return "Java 语言程序设计";
}