SpringMVC的Controller层参数绑定以及返回值

当客户端通过get或post请求发送来的参数通过Controller中方法的参数接受，叫做参数绑定

Controller方法的返回值1：返回void类型

[java] view plain copy

print ?

1. @RequestMapping(“/test_void.action”)  
2. public void controller01(HttpServletRequest request,HttpServletResponse response) throws Exception{  
3. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>request.setCharacterEncoding(“utf-8”);  
4. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>String username = request.getParameter(“username”);//通过HttpServletRequest获得请求参数  
5.     System.out.println(”用户名:”+username);  
6.     request.setAttribute(”username”,username);  
7.     User u = new User();  
8. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>u.setUsername(username);  
9. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>userService.insertUser(u);//插入数据库  
10.     request.getRequestDispatcher(”/WEB-INF/jsp/success.jsp”).forward(request, response);//转发  
11. }  

@RequestMapping("/test_void.action")
public void controller01(HttpServletRequest request,HttpServletResponse response) throws Exception{
  request.setCharacterEncoding("utf-8");
  String username = request.getParameter("username");//通过HttpServletRequest获得请求参数
    System.out.println("用户名:"+username);
    request.setAttribute("username",username);
    User u = new User();
  u.setUsername(username);
  userService.insertUser(u);//插入数据库
    request.getRequestDispatcher("/WEB-INF/jsp/success.jsp").forward(request, response);//转发
}

Controller方法的返回值2：返回ModelAndView

[java] view plain copy

print ?

1. @RequestMapping(“/test_modelandview.action”)  
2. public ModelAndView controller02(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);//转码，Tomcat默认是iso-8859-1  
4.     String username = request.getParameter(”username”);  
5.     System.out.println(”用户名:”+username);  
6.     ModelAndView modelAndView = new ModelAndView();<span style=“margin:0px;padding:0px;white-space:pre;”>   </span>//new一个ModelAndView  
7.     modelAndView.addObject(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>//相当于request.setAttribute(attrName,attrValue);  
8.     modelAndView.setViewName(”WEB-INF/jsp/success.jsp”);//视图跳转  
9.     return modelAndView;  
10. }  

@RequestMapping("/test_modelandview.action")
public ModelAndView controller02(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");//转码，Tomcat默认是iso-8859-1
    String username = request.getParameter("username");
    System.out.println("用户名:"+username);
    ModelAndView modelAndView = new ModelAndView();   //new一个ModelAndView
    modelAndView.addObject("username",username);  //相当于request.setAttribute(attrName,attrValue);
    modelAndView.setViewName("WEB-INF/jsp/success.jsp");//视图跳转
    return modelAndView;
}

Controller方法的返回值3：返回String类型（逻辑视图）

[java] view plain copy

print ?

1. @RequestMapping(“/test_string.action”)  
2. public String controller03(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//转码  
4.     String username = request.getParameter(”username”);  
5.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//设置请求参数  
6.     System.out.println(”用户名:”+username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>  
7.     return “/WEB-INF/jsp/success.jsp”;<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//返回String类型，代表逻辑视图  
8. }     

@RequestMapping("/test_string.action")
public String controller03(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");    //转码
    String username = request.getParameter("username");
    request.setAttribute("username",username);    //设置请求参数
    System.out.println("用户名:"+username);  
    return "/WEB-INF/jsp/success.jsp";    //返回String类型，代表逻辑视图
}   

Controller方法的返回值4：方法的参数是Model，返回值是String类型（逻辑视图）

[html] view plain copy

print ?

1. @RequestMapping(“/test_model.action”)  
2. public String controller04(HttpServletRequest request,Model model) throws Exception{  
3. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>request.setCharacterEncoding(“utf-8”);  
4. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>String username = request.getParameter(“username”);  
5. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>model.addAttribute(“username”, username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>//等价于request.setAttribute(attrName,attrValue);  
6. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>System.out.println(“用户名:”+username);  
7. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>return ”/WEB-INF/jsp/success.jsp”;<span style=“margin:0px;padding:0px;white-space:pre;”> </span>//返回String类型，跳转到逻辑视图  
8. }  

@RequestMapping("/test_model.action")
public String controller04(HttpServletRequest request,Model model) throws Exception{
  request.setCharacterEncoding("utf-8");
  String username = request.getParameter("username");
  model.addAttribute("username", username);  //等价于request.setAttribute(attrName,attrValue);
  System.out.println("用户名:"+username);
  return "/WEB-INF/jsp/success.jsp"; //返回String类型，跳转到逻辑视图
}

Controller方法的返回值5：返回重定向redirect后的逻辑视图名

[java] view plain copy

print ?

1. @RequestMapping(“/test_redirect.action”)  
2. public String controller05(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);  
4.     String username = request.getParameter(”username”);  
5.     User u = new User();  
6.     u.setUsername(username);  
7.     userService.insertUser(u);  
8.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//由于是redirect，所以请求参数失效  
9.     return “redirect:/controller/test_model.action”;//redirect：重定向到一个Controller里  
10. }  

@RequestMapping("/test_redirect.action")
public String controller05(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");
    String username = request.getParameter("username");
    User u = new User();
    u.setUsername(username);
    userService.insertUser(u);
    request.setAttribute("username",username);    //由于是redirect，所以请求参数失效
    return "redirect:/controller/test_model.action";//redirect：重定向到一个Controller里
}

Controller方法的返回值6：返回farward转发后的逻辑视图名

[java] view plain copy

print ?

1. @RequestMapping(“/test_forword.action”)  
2.     public String controller06(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);  
4.     String username = request.getParameter(”username”);  
5.     User u = new User();  
6.     u.setUsername(username);  
7.     userService.insertUser(u);  
8.     System.out.println(”用户名:”+username);  
9.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//由于是转发，所以请求参数有效  
10.     return “forward:/controller/test_model.action”;//转发，跳转到一个Controller里  
11. }  

@RequestMapping("/test_forword.action")
    public String controller06(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");
    String username = request.getParameter("username");
    User u = new User();
    u.setUsername(username);
    userService.insertUser(u);
    System.out.println("用户名:"+username);
    request.setAttribute("username",username);    //由于是转发，所以请求参数有效
    return "forward:/controller/test_model.action";//转发，跳转到一个Controller里
}

参数绑定

参数绑定的第一种方法：绑定普通类型

[java] view plain copy

print ?

1. //参数绑定的第一种方法：客户端提交的请求的input的name属性会和Controller方法的参数名字一致才会绑定  
2. @RequestMapping(“/test_parambinding01.action”)  
3. public void controller07(HttpServletRequest request,HttpServletResponse response,String username,String password) throws Exception{  
4.     //必须进行转码  
5.     username = new String(username.getBytes(“iso8859-1”),“UTF-8”);  
6.     request.setAttribute(”username”,username);  
7.     request.getRequestDispatcher(”/WEB-INF/jsp/success.jsp”).forward(request, response);      
8. }  

//参数绑定的第一种方法：客户端提交的请求的input的name属性会和Controller方法的参数名字一致才会绑定
@RequestMapping("/test_parambinding01.action")
public void controller07(HttpServletRequest request,HttpServletResponse response,String username,String password) throws Exception{
    //必须进行转码
    username = new String(username.getBytes("iso8859-1"),"UTF-8");
    request.setAttribute("username",username);
    request.getRequestDispatcher("/WEB-INF/jsp/success.jsp").forward(request, response);    
}

参数绑定的第二种方法：绑定pojo类

[java] view plain copy

print ?

1. //参数绑定的第二种方法:客户端的input标签的那么属性必须和User的属性名对应才可以映射成功  
2. @RequestMapping(“/test_parambinding02.action”)  
3. public ModelAndView controller08(HttpServletRequest request,User user) throws Exception{  
4.     //必须进行转码  
5.     user.setUsername(new String(user.getUsername().getBytes(“iso-8859-1”),“utf-8”));  
6.     userService.insertUser(user);  
7.     ModelAndView modelAndView = new ModelAndView();  
8.     request.setCharacterEncoding(”utf-8”);  
9.     modelAndView.addObject(”username”,user.getUsername());  
10.     modelAndView.addObject(”password”,user.getPassword());  
11.     modelAndView.setViewName(”/WEB-INF/jsp/success.jsp”);  
12.     return modelAndView;  
13. }  

//参数绑定的第二种方法:客户端的input标签的那么属性必须和User的属性名对应才可以映射成功
@RequestMapping("/test_parambinding02.action")
public ModelAndView controller08(HttpServletRequest request,User user) throws Exception{
    //必须进行转码
    user.setUsername(new String(user.getUsername().getBytes("iso-8859-1"),"utf-8"));
    userService.insertUser(user);
    ModelAndView modelAndView = new ModelAndView();
    request.setCharacterEncoding("utf-8");
    modelAndView.addObject("username",user.getUsername());
    modelAndView.addObject("password",user.getPassword());
    modelAndView.setViewName("/WEB-INF/jsp/success.jsp");
    return modelAndView;
}

参数绑定的第三种方法：当input的name与controller的参数名不一致时，可以采用@RequestParam注解

[java] view plain copy

print ?

1. @RequestMapping(“test_RequestParam.action”)  
2. //将客户端的请求参数”username”与”uname”绑定  
3. public ModelAndView controller09(@RequestParam(value=“username”) String uname,@RequestParam(value=“password”)String pwd) throws Exception{  
4.     uname = new String(uname.getBytes(“iso-8859-1”),“utf-8”);     
5.     ModelAndView modelAndView = new ModelAndView();  
6.     modelAndView.addObject(”username”,uname);  
7.     modelAndView.setViewName(”/WEB-INF/jsp/success.jsp”);  
8.     return modelAndView;  
9. }  

@RequestMapping("test_RequestParam.action")
//将客户端的请求参数"username"与"uname"绑定
public ModelAndView controller09(@RequestParam(value="username") String uname,@RequestParam(value="password")String pwd) throws Exception{
    uname = new String(uname.getBytes("iso-8859-1"),"utf-8");   
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.addObject("username",uname);
    modelAndView.setViewName("/WEB-INF/jsp/success.jsp");
    return modelAndView;
}

                </div>

当客户端通过get或post请求发送来的参数通过Controller中方法的参数接受，叫做参数绑定

Controller方法的返回值1：返回void类型

[java] view plain copy

print ?

1. @RequestMapping(“/test_void.action”)  
2. public void controller01(HttpServletRequest request,HttpServletResponse response) throws Exception{  
3. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>request.setCharacterEncoding(“utf-8”);  
4. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>String username = request.getParameter(“username”);//通过HttpServletRequest获得请求参数  
5.     System.out.println(”用户名:”+username);  
6.     request.setAttribute(”username”,username);  
7.     User u = new User();  
8. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>u.setUsername(username);  
9. <span style=”margin:0px;padding:0px;white-space:pre;”>  </span>userService.insertUser(u);//插入数据库  
10.     request.getRequestDispatcher(”/WEB-INF/jsp/success.jsp”).forward(request, response);//转发  
11. }  

@RequestMapping("/test_void.action")
public void controller01(HttpServletRequest request,HttpServletResponse response) throws Exception{
  request.setCharacterEncoding("utf-8");
  String username = request.getParameter("username");//通过HttpServletRequest获得请求参数
    System.out.println("用户名:"+username);
    request.setAttribute("username",username);
    User u = new User();
  u.setUsername(username);
  userService.insertUser(u);//插入数据库
    request.getRequestDispatcher("/WEB-INF/jsp/success.jsp").forward(request, response);//转发
}

Controller方法的返回值2：返回ModelAndView

[java] view plain copy

print ?

1. @RequestMapping(“/test_modelandview.action”)  
2. public ModelAndView controller02(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);//转码，Tomcat默认是iso-8859-1  
4.     String username = request.getParameter(”username”);  
5.     System.out.println(”用户名:”+username);  
6.     ModelAndView modelAndView = new ModelAndView();<span style=“margin:0px;padding:0px;white-space:pre;”>   </span>//new一个ModelAndView  
7.     modelAndView.addObject(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>//相当于request.setAttribute(attrName,attrValue);  
8.     modelAndView.setViewName(”WEB-INF/jsp/success.jsp”);//视图跳转  
9.     return modelAndView;  
10. }  

@RequestMapping("/test_modelandview.action")
public ModelAndView controller02(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");//转码，Tomcat默认是iso-8859-1
    String username = request.getParameter("username");
    System.out.println("用户名:"+username);
    ModelAndView modelAndView = new ModelAndView();   //new一个ModelAndView
    modelAndView.addObject("username",username);  //相当于request.setAttribute(attrName,attrValue);
    modelAndView.setViewName("WEB-INF/jsp/success.jsp");//视图跳转
    return modelAndView;
}

Controller方法的返回值3：返回String类型（逻辑视图）

[java] view plain copy

print ?

1. @RequestMapping(“/test_string.action”)  
2. public String controller03(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//转码  
4.     String username = request.getParameter(”username”);  
5.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//设置请求参数  
6.     System.out.println(”用户名:”+username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>  
7.     return “/WEB-INF/jsp/success.jsp”;<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//返回String类型，代表逻辑视图  
8. }     

@RequestMapping("/test_string.action")
public String controller03(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");    //转码
    String username = request.getParameter("username");
    request.setAttribute("username",username);    //设置请求参数
    System.out.println("用户名:"+username);  
    return "/WEB-INF/jsp/success.jsp";    //返回String类型，代表逻辑视图
}   

Controller方法的返回值4：方法的参数是Model，返回值是String类型（逻辑视图）

[html] view plain copy

print ?

1. @RequestMapping(“/test_model.action”)  
2. public String controller04(HttpServletRequest request,Model model) throws Exception{  
3. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>request.setCharacterEncoding(“utf-8”);  
4. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>String username = request.getParameter(“username”);  
5. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>model.addAttribute(“username”, username);<span style=“margin:0px;padding:0px;white-space:pre;”>  </span>//等价于request.setAttribute(attrName,attrValue);  
6. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>System.out.println(“用户名:”+username);  
7. <span style=“margin:0px;padding:0px;white-space:pre;”>  </span>return ”/WEB-INF/jsp/success.jsp”;<span style=“margin:0px;padding:0px;white-space:pre;”> </span>//返回String类型，跳转到逻辑视图  
8. }  

@RequestMapping("/test_model.action")
public String controller04(HttpServletRequest request,Model model) throws Exception{
  request.setCharacterEncoding("utf-8");
  String username = request.getParameter("username");
  model.addAttribute("username", username);  //等价于request.setAttribute(attrName,attrValue);
  System.out.println("用户名:"+username);
  return "/WEB-INF/jsp/success.jsp"; //返回String类型，跳转到逻辑视图
}

Controller方法的返回值5：返回重定向redirect后的逻辑视图名

[java] view plain copy

print ?

1. @RequestMapping(“/test_redirect.action”)  
2. public String controller05(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);  
4.     String username = request.getParameter(”username”);  
5.     User u = new User();  
6.     u.setUsername(username);  
7.     userService.insertUser(u);  
8.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//由于是redirect，所以请求参数失效  
9.     return “redirect:/controller/test_model.action”;//redirect：重定向到一个Controller里  
10. }  

@RequestMapping("/test_redirect.action")
public String controller05(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");
    String username = request.getParameter("username");
    User u = new User();
    u.setUsername(username);
    userService.insertUser(u);
    request.setAttribute("username",username);    //由于是redirect，所以请求参数失效
    return "redirect:/controller/test_model.action";//redirect：重定向到一个Controller里
}

Controller方法的返回值6：返回farward转发后的逻辑视图名

[java] view plain copy

print ?

1. @RequestMapping(“/test_forword.action”)  
2.     public String controller06(HttpServletRequest request) throws Exception{  
3.     request.setCharacterEncoding(”utf-8”);  
4.     String username = request.getParameter(”username”);  
5.     User u = new User();  
6.     u.setUsername(username);  
7.     userService.insertUser(u);  
8.     System.out.println(”用户名:”+username);  
9.     request.setAttribute(”username”,username);<span style=“margin:0px;padding:0px;white-space:pre;”>    </span>//由于是转发，所以请求参数有效  
10.     return “forward:/controller/test_model.action”;//转发，跳转到一个Controller里  
11. }  

@RequestMapping("/test_forword.action")
    public String controller06(HttpServletRequest request) throws Exception{
    request.setCharacterEncoding("utf-8");
    String username = request.getParameter("username");
    User u = new User();
    u.setUsername(username);
    userService.insertUser(u);
    System.out.println("用户名:"+username);
    request.setAttribute("username",username);    //由于是转发，所以请求参数有效
    return "forward:/controller/test_model.action";//转发，跳转到一个Controller里
}

参数绑定

参数绑定的第一种方法：绑定普通类型

[java] view plain copy

print ?

1. //参数绑定的第一种方法：客户端提交的请求的input的name属性会和Controller方法的参数名字一致才会绑定  
2. @RequestMapping(“/test_parambinding01.action”)  
3. public void controller07(HttpServletRequest request,HttpServletResponse response,String username,String password) throws Exception{  
4.     //必须进行转码  
5.     username = new String(username.getBytes(“iso8859-1”),“UTF-8”);  
6.     request.setAttribute(”username”,username);  
7.     request.getRequestDispatcher(”/WEB-INF/jsp/success.jsp”).forward(request, response);      
8. }  

//参数绑定的第一种方法：客户端提交的请求的input的name属性会和Controller方法的参数名字一致才会绑定
@RequestMapping("/test_parambinding01.action")
public void controller07(HttpServletRequest request,HttpServletResponse response,String username,String password) throws Exception{
    //必须进行转码
    username = new String(username.getBytes("iso8859-1"),"UTF-8");
    request.setAttribute("username",username);
    request.getRequestDispatcher("/WEB-INF/jsp/success.jsp").forward(request, response);    
}

参数绑定的第二种方法：绑定pojo类

[java] view plain copy

print ?

1. //参数绑定的第二种方法:客户端的input标签的那么属性必须和User的属性名对应才可以映射成功  
2. @RequestMapping(“/test_parambinding02.action”)  
3. public ModelAndView controller08(HttpServletRequest request,User user) throws Exception{  
4.     //必须进行转码  
5.     user.setUsername(new String(user.getUsername().getBytes(“iso-8859-1”),“utf-8”));  
6.     userService.insertUser(user);  
7.     ModelAndView modelAndView = new ModelAndView();  
8.     request.setCharacterEncoding(”utf-8”);  
9.     modelAndView.addObject(”username”,user.getUsername());  
10.     modelAndView.addObject(”password”,user.getPassword());  
11.     modelAndView.setViewName(”/WEB-INF/jsp/success.jsp”);  
12.     return modelAndView;  
13. }  

//参数绑定的第二种方法:客户端的input标签的那么属性必须和User的属性名对应才可以映射成功
@RequestMapping("/test_parambinding02.action")
public ModelAndView controller08(HttpServletRequest request,User user) throws Exception{
    //必须进行转码
    user.setUsername(new String(user.getUsername().getBytes("iso-8859-1"),"utf-8"));
    userService.insertUser(user);
    ModelAndView modelAndView = new ModelAndView();
    request.setCharacterEncoding("utf-8");
    modelAndView.addObject("username",user.getUsername());
    modelAndView.addObject("password",user.getPassword());
    modelAndView.setViewName("/WEB-INF/jsp/success.jsp");
    return modelAndView;
}

参数绑定的第三种方法：当input的name与controller的参数名不一致时，可以采用@RequestParam注解

[java] view plain copy

print ?

1. @RequestMapping(“test_RequestParam.action”)  
2. //将客户端的请求参数”username”与”uname”绑定  
3. public ModelAndView controller09(@RequestParam(value=“username”) String uname,@RequestParam(value=“password”)String pwd) throws Exception{  
4.     uname = new String(uname.getBytes(“iso-8859-1”),“utf-8”);     
5.     ModelAndView modelAndView = new ModelAndView();  
6.     modelAndView.addObject(”username”,uname);  
7.     modelAndView.setViewName(”/WEB-INF/jsp/success.jsp”);  
8.     return modelAndView;  
9. }  

@RequestMapping("test_RequestParam.action")
//将客户端的请求参数"username"与"uname"绑定
public ModelAndView controller09(@RequestParam(value="username") String uname,@RequestParam(value="password")String pwd) throws Exception{
    uname = new String(uname.getBytes("iso-8859-1"),"utf-8");   
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.addObject("username",uname);
    modelAndView.setViewName("/WEB-INF/jsp/success.jsp");
    return modelAndView;
}

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