web路由的java简单实现思路

https://juejin.cn/pins/recommended
协议://地址/端口/路由地址
                我们只关注这里就可以了
前面的容器处理了
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2.1定义注解
2.2系统初始化的时候扫描注解，解解析路由缓存起来
2.3接收请求的时候由自定义过滤器进行拦截
2.4解析请求的路径，并匹配缓存的路由，处理业务
2.5注意对于业务处理的action进行单例实例化
2.6目前这里这里处理方法还只是servlet的request,response只是个例子了解下流程
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@Retention(RetentionPolicy.RUNTIME)
public @interface PathAnnotation {
    String path();//这里是路径
    String type();//这里是类型
}
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这里就是遍历读取class文件，找到注解为PathAnnotation的类
解析路径然后缓存起来
//路由对应的实体类
public class Route {
  /** 路径*/
  private String path;
  /** 执行方法*/
  private String method;
  /** 方法类型*/
  private String type;
  /** action控制类*/
  private Object action;
 } 
 /**
 * 扫描的class类,解析路径缓存起来routeList
 * @param path
 * @return
 * @throws IllegalAccessException
 * @throws InstantiationException
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public void addAllRoutes(Set<Class> actionClass) throws InstantiationException, IllegalAccessException {
if (null != actionClass) {
 for (Class cls : actionClass) {
  PathAnnotation pa = (PathAnnotation) cls.getAnnotation(PathAnnotation.class);
  String routPath = "";
  if (null != pa) {
   routPath = pa.path();
  }
  Method[] methods = cls.getMethods();
  for (Method m : methods) {
   pa = m.getAnnotation(PathAnnotation.class);
   if (null == pa) {
      continue;
  }
  routPath += "/" + pa.path();
  Route rt = new Route(routPath, m.getName(), pa.type(), BeanUtil.getBeanUtil().getObj(cls));
        logger.info("加载路由：" + rt.toString());
        routeList.add(rt);
      }
    }
   }
}
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/**
 * 这里是个匹配的路径内容
 * 这里的匹配路径所有的都根据/来的
 * @param rs
 * @param path
 * @return
 */
public static  Route findRoute(Routes rs,String path) {
  if(null==rs||rs.getRouteList().size()<1) {
    return null;
  }else {
    List<Route> allRoute=rs.getRouteList();
    //首先要把路径给格式化为标准的路径
               if(null==path) {
            return null;
               }else {
                /**
                 * 1.这里首先要去掉开始的项目地址，然后把字符\转换为/
                 * 2.如何是/结尾的要去掉
                 * 3.开始的项目地址如何去掉
                 * 4.项目路径匹配返回正常的路由
                 */  
                String currentPath=path.trim().replace('\\', '/');
                if(currentPath.endsWith("/")) {
                   currentPath=currentPath.substring(0,currentPath.length()-1);
                }
                if(currentPath.startsWith("/")) {
                   currentPath=currentPath.substring(1,currentPath.length()); 
                }
                for(Route rt:allRoute) {
                        if(rt.getPath().equals(currentPath)) {
                                return rt;
                        }
                }
               }
        return null;
  }
}
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<filter>
  <filter-name>pingpang</filter-name>
  <filter-class>com.pingpang.core.Core</filter-class>
  <init-param>
     <param-name>autoPackage</param-name>
           <!--这里是扫描的包路径-->
     <param-value>com.pingpang.test</param-value>
     </init-param>
</filter>
<filter-mapping>
  <filter-name>pingpang</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>
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//路由注解的测试
@PathAnnotation(path = "hello", type = "")
public class PingPangTest {
  @PathAnnotation(path = "test", type = "")
  public void helloWord(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
        System.out.println("-----------");
        request.getRequestDispatcher("/login.jsp").forward(request, response);
   }
}
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