Route order

在默认情况下routes的排序是按照添加添加进router的顺序进行排序的.

当router接受到一个请求时, router会遍历自身的每一个route查看是否与请求匹配,如果匹配的话,该route的handler就会被调用.

如果handler随后调用了下一个handler, 那么下一个与之匹配的route也会被调用.

  1. Route route1 = router.route("/some/path/").handler(routingContext -> {
  3.   HttpServerResponse response = routingContext.response();
  4.   // enable chunked responses because we will be adding data as
  5.   // we execute over other handlers. This is only required once and
  6.   // only if several handlers do output.
  7.   response.setChunked(true);
  9.   response.write("route1\n");
  11.   // Now call the next matching route
  12.   routingContext.next();
  13. });
  15. Route route2 = router.route("/some/path/").handler(routingContext -> {
  17.   HttpServerResponse response = routingContext.response();
  18.   response.write("route2\n");
  20.   // Now call the next matching route
  21.   routingContext.next();
  22. });
  24. Route route3 = router.route("/some/path/").handler(routingContext -> {
  26.   HttpServerResponse response = routingContext.response();
  27.   response.write("route3");
  29.   // Now end the response
  30.   routingContext.response().end();
  31. });

在上面的例子中，输出结果为：

  1. route1
  2. route2
  3. route3

/some/path开头的请求都是按照刚才的那个顺序进行route调用的.

如果你想要改变route的调用顺序,你可以使用order()方法,向其指定一个指定值.

Routes在router中的位置是按照他们添加进去的时间顺序进行排序的, 而且他们的位置是从0开始的.

当然像上文所说的,你还可以调用order()方法改变这个排序. 需要注意的是序号可以是负数, 例如你想要某个route在序号0的route之前执行,你就可以将某个route序号指定为-1.

下例中我们改变了route2的序号,确保他在route1之前执行.

  1. Route route1 = router.route("/some/path/").handler(routingContext -> {
  3.   HttpServerResponse response = routingContext.response();
  4.   response.write("route1\n");
  6.   // Now call the next matching route
  7.   routingContext.next();
  8. });
  10. Route route2 = router.route("/some/path/").handler(routingContext -> {
  12.   HttpServerResponse response = routingContext.response();
  13.   // enable chunked responses because we will be adding data as
  14.   // we execute over other handlers. This is only required once and
  15.   // only if several handlers do output.
  16.   response.setChunked(true);
  18.   response.write("route2\n");
  20.   // Now call the next matching route
  21.   routingContext.next();
  22. });
  24. Route route3 = router.route("/some/path/").handler(routingContext -> {
  26.   HttpServerResponse response = routingContext.response();
  27.   response.write("route3");
  29.   // Now end the response
  30.   routingContext.response().end();
  31. });
  33. // Change the order of route2 so it runs before route1
  34. route2.order(-1);

接下来我们就看到了我们所期望的结果

  1. route2
  2. route1
  3. route3

如果俩个route有相同的序号,那么他们会按照添加的顺序进行执行. 你还可以通过调用last()方法将某个route放到最后一个.