springmvc学习笔记(常用注解)

springmvc学习笔记(常用注解)

1. @Controller

@Controller

@Controller

DispatcherServlet

@Controller

@RequestMapping

<!-- 扫描包路径com.lizj.controller下的所有类, 将带有注解的类注册到spring容器中 -->
<context:component-scan base-package="com.lizj.controller" />

<!-- 视图解释器 -->
<!-- 配置的视图解析器为InternalResourceViewResolver, 并为其添加了前缀prefix和后缀suffix属性 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!-- 前缀 -->
<property name="prefix" value="/WEB-INF/jsp/" />
<!-- 后缀 -->
<property name="suffix" value=".jsp" />
</bean>

@Controller

/**
* 基于注解的控制器
*/
@Controller
public class HelloController {

}

2. @RequestMapping

2.1 @RequestMapping注解

@RequestMapping

@RequestMapping

/**
* 基于注解的控制器
*/
@Controller
public class HelloController {

@RequestMapping("/hello")
public String sayHello(HttpServletRequest request) {
model.addAttribute("message", "Hello World");
return "helloworld";
}
}

@RequestMapping

@RequestMapping

@RequestMapping

@RequestMapping("/user")
@RequestMapping(value="/user")

多个请求地址映射到同一个方法
@RequestMapping(value={"/user", "/customer"})

// 此方法只处理POST请求.
@RequestMapping(value="/user", method=RequestMethod.POST)

// 此方法既支持POST请求, 又支持GET请求
@RequestMapping(value="/user", method={RequestMethod.POST,RequestMethod.GET})

2.2 支持的方法参数类型

javax.servlet.ServletRequest

javax.servlet.http.HttpServletRequest

javax.servlet.ServletResponse

javax.servlet.http.HttpServletResponse

javax.servlet.http.HttpSession

org.springframework.web.context.request.WebRequest

org.springframework.web.context.request.NativeWebRequeset

java.util.Locale

java.io.InputStream

java.io.Reader

Servlet API

java.io.OutputSteam

java.io.Writer

Servlet API

java.security.Principal

org.springframework.http.HttpEntity<T>

org.springframework.web.servlet.mvc.support.RedirectAttributes

org.springframework.validation.Errors

org.springframework.validation.BindingResult

org.springframework.web.bind.support.SessionStatus

org.springframework.web.util.UriComponentsBuilder

@PathVariable

@MatrixVariable

java.util.Map

org.springframework.io.Model

org.springframework.ui.ModelMap

@RequestParam

@RequestHeader

@RequestBody

HttpMessageConverter

@RequestPart

Errors

BindingResult

org.springframework.ui.Model

java.util.Map

Model

/*
* springmvc中controller中的方法参数, 支持大多数常用的数据类型,
* 如: String, int....
*/
// 需要注意的是, 此处请求参数名必须与方法参数名一致, 否则获取不到参数值, 后面@RequestParam再做详细解释
@RequestMapping("/get")
public String getUser(String id, Model model) {
User user = null;
for(int i=0; i<userList.size(); i++) {
User u = userList.get(i);
if(u.getId().equals(id)) {
user = u;
break ;
}
}
if(user == null) {
user = new User();
user.setId("001");
user.setName("张三");
user.setAge(18);
user.setSex("男");
}
// 向model中添加数据
model.addAttribute("user", user);
// 返回视图名称
return "user/oneuser";
}

2.3 支持的方法返回类型

org.springframework.web.servlet.ModelAndView

org.springframework.ui.Model

java.util.Map<K, V>

org.springframework.web.servlet.View

java.lang.String

HttpEntity<?>

ResponseEntity<?>

java.util.concurrent.Callable

org.springframework.web.context.request.async.DeferredResult<?>

void

ModelAndView

ModelAndview

// 添加模型数据
addObject(String attributeName, Object attributeValue);
// 设置视图
setViewName(String viewName);

3. @RequestParam

@RequestParam

@RequestParam

@RequestMapping(value="/add", method=RequestMethod.POST)
public String add(@RequestParam("name") String name,
@RequestParam("author") String author) {

}

@RequestParam

4. @PathVariable

@PathVariable

String

@RequestMapping(value="/book/{bookId}")
public ModelAndView get(@PathVariable int bookId)

5. @RequestHeader

@RequestHeader

@RequestHeader

public void testRequestHeader(
@RequestHeader("User-Agent") String userAgent,
@RequestHeader("Accept") String[] accepts) {
// ...
}

6. @CookieValue

@CookieValue

@CookieValue

7. @SessionAttributes

@SessionAttributes

Model

session

@SessionAttributes

@SessionAttributes

8. @ModelAttribute

@ModelAttribute

@ModelAttribute

String

value

@ModelAttribute

Controller

Controller

@ModelAttribute

@ModelAttribute("paramName")
public String getParam(@RequestParam("param") String param) {
return param;
}

param

paramName

model

model

@ModelAttribute
// 这次没有使用@ModelAttribute注解的value属性
public User getUserById(String userId) {
return userService.getUserById(userId);
}

@RuquestParam

User

@ModelAttribute

value

value

value

@ModelAttribute

@ModelAttribute
public void getUserById(String userId, Model model) {
model.addAttribute("user", userService.getUserById(userId));
}

Model

@ModelAttribute

@RequestMapping

@RequestMapping("/show")
@ModelAttribute("username")
public String show(String userId) {
User user = userService.getUserById(userId);
return user.getName();
}

@ModelAttribute

@RequestMapping

show

Model

Model

@ModelAttribute

value

username

@RequestMapping

value

/show

show

@ModelAttribute

@ModelAttribute
public User getUserById(String userId) {
return userService.getUserById(userId);
}

@RequestMapping("/show")
public String show(@ModelAttribute User user) {
return "mac/test05";
}

@ModelAttribute

getUserById()

Model

user

User

show

@ModelAttribute

user

Model

9. @RequestBody 和 @ResponseBody

9.1 @RequestBody

@RequestBody

@RequestBody

ContentType

@RequestParam

@ModelAttribute

@RequestBody

@RequestBody

@RequestBody

9.2 @ResponseBody

@ResponseBody

Controller

9.3 示例

9.3.1 springmvc-servlet.xml

<!-- 自动注册RequestMappingHandlerMapping和RequestMappingHandlerAdapter -->
<mvc:annotation-driven />

<!-- DispatcherServlet会拦截所有请求, 会将静态文件(如js文件)的请求看成路径, 就会找不到对应的静态文件 -->
<!-- 此配置将使用默认的servlet响应静态文件, 避免出现上述情况 -->
<mvc:default-servlet-handler/>

org.springframework.web.servlet.HandlerMapping=org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,\org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping

org.springframework.web.servlet.HandlerAdapter=org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,\org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,\org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter

9.3.2 pom.xml

<!-- jackson -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.6.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.6.2</version>
</dependency>