Spring Boot 特性以及代码模板实例

1. SpringBoot工程
2. 参数解析
3. HTTP Method
4. Request / Response / Session
5. Error/重定向
6. Logger
7. IoC
8. AOP/Aspect

 

1：SpringBoot工程

 

框架学习，首先接触看官方文档：（先看做什么，官方的文档细节先忽略，用到去查找）

start.spring.io

 

//controller演示

public class IndexController {

@RequestMapping(path = {"/","/index"})

@ResponseBody

public String Index( ) {

return " name ";

}

}

 

2：参数解析

//controller携带参数的演示,路径里面的参数可以解析到函数里面

@RequestMapping(value = "/profile/{groupId}/{userId}")

@ResponseBody

public String profile(@PathVariable("groupId") String groupId,

@PathVariable("userId") int userId,

@RequestParam(value = "type", defaultValue = "1") int type,

@RequestParam(value = "key", defaultValue = "nowcoder") String key) {

return String.format("{%s},{%d},{%d},{%s}", groupId, userId, type, key);

}

 

//设置 type =

//设置 key =

//controller携带参数，并且携带@requestparam

@RequestMapping(value = "/profile/{groupId}/{userId}")

@ResponseBody

public String profile(@PathVariable("groupId") String groupId,

@PathVariable("userId") int userId,

@RequestParam(value = "type", defaultValue = "1") int type,

@RequestParam(value = "key", defaultValue = "nowcoder") String key) {

return String.format("{%s},{%d},{%d},{%s}", groupId, userId, type, key);

}

 

 

 

3：HTTP Method

HTTP Method（代码演示）

GET 获取接口信息

HEAD 紧急查看接口HTTP的头

POST 提交数据到服务器

PUT 支持幂等性的POST //执行两次是一样的结果；

 

DELETE 删除服务器上的资源

OPITIONS 查看支持的方法

可以设置get post

Fidder web debugger工具

 

4：Request / Response / Session

 

request HttpServletResponse

参数解析 response.addCookie(new

Cookie(key, value));

response.addHeader(key, value);

cookie读取

http请求字段

文件上传

HttpServletRequest

request.getHeaderNames();

request.getMethod()

request.getPathInfo()

request.getQueryString()

response

页面内容返回

cookie下发

http字段设置，headers

 

 

5：Error/重定向

 

//重定向

//301：永久转移

//302：临时转移

 

//异常的统一处理

@RequestMapping(path = {"/admin"}, method = {RequestMethod.GET})

@ResponseBody

public String admin(@RequestParam("key") String key) {

if ("admin".equals( key )) {

return "hello admin";

}

throw new IllegalArgumentException( "参数不对" );

}

 

@ExceptionHandler()

@ResponseBody

public String error(Exception e) {

return "出现了错误error:" + e.getMessage();

}

6：IoC 控制反转：无需关注对象的初始化（享元模式）

servicecs包下面：通过标记@Services来设置对象，

controller包下面：通过@Autowired，直接引入对象无需初始化。不需要new Services中的对象；

 

 

7：AOP/Aspect 面向切面

@Aspect

@Component

public class LogAspect {

private static final Logger logger = LoggerFactory.getLogger(LogAspect.class);

 

@Before("execution(* com.nowcoder.controller.*Controller.*(..))")

public void beforeMethod(JoinPoint joinPoint) {

StringBuilder sb = new StringBuilder();

for (Object arg : joinPoint.getArgs()) {

sb.append("arg:" + arg.toString() + "|");

}//切点打印参数

logger.info("before method:" + sb.toString());

}

 

@After("execution(* com.nowcoder.controller.IndexController.*(..))")

public void afterMethod() {

logger.info("after method" + new Date());

}

}