SpringMVC入门

三层架构
- 表现层，业务层，数据访问层
MVC
- Model：模型层
- View：视图层
- Controller：控制层
核心组件
- 前端控制器：DispatcherServlet

接受HTTPget请求传参的两种方式

@Controller
@RequestMapping("/alpha")
public class AlphaController{
    
	//方式1
    @RequestMapping(path = "/students", method = RequestMethod.GET)
    @ResponseBody
    public String getStudents(
            @RequestParam(name="current", required = false, defaultValue = "1") int current,
            @RequestParam(name="limit", required = false, defaultValue = "10") int limit){

        System.out.println(current);
        System.out.println(limit);
        return "some students";
    }
	
    //方式2
    @RequestMapping(path = "/student/{id}", method = RequestMethod.GET)
    @ResponseBody
    public String getStudent(@PathVariable("id") int id){
        System.out.println(id);
        return "a student";
    }
}

接受HTTPpost请求提交数据

@RequestMapping(path = "/student", method = RequestMethod.POST)
@ResponseBody
public String saveStudent(String name, int age){
    System.out.println(name);
    System.out.println(age);
    return "success";
}

利用thymeleaf向浏览器显示动态数据

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Teacher</title>
</head>
<body>
    <p th:text="${name}"></p>
    <p th:text="${age}"></p>
</body>
</html>

方式1
@RequestMapping(path = "/teacher", method = RequestMethod.GET)
public ModelAndView getTeacher(){
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.addObject("name", "张三");
    modelAndView.addObject("age", 30);
    modelAndView.setViewName("/demo/view");
    return modelAndView;
}

方式2
@RequestMapping(path = "/school", method = RequestMethod.GET)
public String getSchool(Model model){
    model.addAttribute("name", "寄大学");
    model.addAttribute("age", 7);
    return "/demo/view";
}

向浏览器返回Json格式数据举例

@RequestMapping(path = "/emp", method = RequestMethod.GET)
@ResponseBody
public Map<String, Object> getEmp(){
    Map<String, Object> emp = new HashMap<>();
    emp.put("name", "张三");
    emp.put("age", 30);
    emp.put("salary", 9000);
    return emp;
}