Question

springmvc 获取请求参数的几种方式

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Answer 1

1. 几种页面跳转方式

1.1 通过HttpServletResponse的API直接输出（不需要配置渲染器）
案例： @Controller
public class RequestController{
@RequestMapping("/resp")
public void handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {
resp.getWriter().println("hello HttpServletResponse");
}
1.2 使用HttpServletResponse 重定向到另一个视图(其他不变 )
@RequestMapping("/resp")
public void handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {
resp.sendRedirect("index.jsp");
}
}
1.3 使用HttpServletRequest 转发（默认访问/下的index.jsp页面 不受渲染器的影响）
@RequestMapping("/resp")
public void handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {
req.setAttribute("message","it's forword ");
req.getRequestDispatcher("index.jsp").forward(req,resp);
}
1.4直接返回jsp页面的名称（无渲染器）
@RequestMapping("/nice")
public String hello1(){
//转发方式1
return "home.jsp";
//转发方式2
return "forward:index.jsp";
//重定向方式
return "redirect:index.jsp";
}
1.5 使用modelandview 需要视图解析器 能指定跳转页面
public class HelloController implements Controller {
@Override
public ModelAndView handleRequest(javax.servlet.http.HttpServletRequest httpServletRequest,
javax.servlet.http.HttpServletResponse httpServletResponse) throws Exception {
ModelAndView mv = new ModelAndView();
//封装要显示到视图的数据
mv.addObject("msg","hello myfirst mvc");
//视图名
mv.setViewName("hello");
return mv;
}
}
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<!--结果视图的前缀-->
<property name="prefix" value="/WEB-INF/jsp/"/>
<!--结果视图的后缀-->
<property name="suffix" value=".jsp"/>
</bean>
1.6
//通过modelmap方式
@RequestMapping("/modelmap")
public String modelHello(String name,ModelMap map){
map.addAttribute("name",name);
System.out.println(name);
return "index.jsp";
}
2. 获取页面参数的几种方式
1、直接把表单的参数写在Controller相应的方法的形参中
案例：
/**
* 1.直接把表单的参数写在Controller相应的方法的形参中
*/
@RequestMapping("/add")
public String add(String username,String password) {
System.out.println("username is:"+username);
System.out.println("password is:"+password);
return "index";
}
2、通过HttpServletRequest接收
案例：
/**
* 2、通过HttpServletRequest接收
*/
@RequestMapping("/add")
public String add(HttpServletRequest request) {
String username=request.getParameter("username");
String password=request.getParameter("password");
System.out.println("username is:"+username);
System.out.println("password is:"+password);
return "index";
}
3、通过一个bean来接收
案例：
public class User {
private Long id;
private String username;
private String password;
public User(){}
public Long getId() {
return id;
}
public String getUsername() {
return username;
}
public String getPassword() {
return password;
}
public void setId(Long id) {
this.id = id;
}
public void setUsername(String username) {
this.username = username;
}
public void setPassword(String password) {
this.password = password;
}
}
/**
* 3、通过一个bean来接收
*/
@RequestMapping("/add")
public String add(User user) {
System.out.println("username is:"+user.getUsername());
System.out.println("password is:"+user.getPassword());
return "index";
}
4、通过@PathVariable获取路径中的参数
案例：
/**
* 4、通过@PathVariable获取路径中的参数
* @param username
* @param password
* @return
*/
@RequestMapping(value="/add/{username}/{password}",method=RequestMethod.GET)
public String addUser4(@PathVariable String username,@PathVariable String password) {
System.out.println("username is:"+username);
System.out.println("password is:"+password);
return "index";
}
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