1.说明
在当前类中编写回退方法会使得代码变得冗余耦合度高，我们可以将回退方法抽取出来到一个指定类中
2.新增 BuyBlockHandler
代码如下：
public class BuyBlockHandler {
// sentinel 回退
public static String buyBlock(@PathVariable String name, @PathVariable Integer count, BlockException e) {
return String.format("【进入 blockHandler 方法】购买%d 份%s 失败，当前购买人数过多，请稍后再试", count, name);
}
}
3.新增 BuyFallBack
代码如下：
public class BuyFallBack {
// sentinel 回退
public static ResponseEntity<String> buyBlock(@PathVariable String name, @PathVariable Integer count, BlockException e) {
return ResponseEntity.ok(String.format("【进入 BuyFallBack 方法】购买%d份%s 失败，当前购买人数过多，请稍后再试", count, name));
}
}
4.改造 BuyController
@RestController
public class BuyController {
@Autowired
private RestTemplate restTemplate;
@GetMapping("buy/{name}/{count}")
@SentinelResource( value = "buy", fallback = "buyFallback", fallbackClass = BuyFallBack.class , blockHandler = "buyBlock", blockHandlerClass = BuyBlockHandler.class , )
public ResponseEntity<String> buy(@PathVariable String name, @PathVariable Integer count) {
if (count >= 20) {
throw new IllegalArgumentException("购买数量过多");
}
if ("miband".equalsIgnoreCase(name)) {
throw new NullPointerException("已售罄");
}
Map<String, Object> params = new HashMap<>(2);
params.put("name", name);
params.put("count", count);
return ResponseEntity.ok( this.restTemplate.getForEntity("http://sentinel-provider/goods/buy/{name}/{count}", String.class, params).getBody());
}
}