Update Sentinel annotation AOP demo

Signed-off-by: Eric Zhao <[email protected]>

Author: sczyh30

sentinel-demo/sentinel-demo-annotation-spring-aop/src/main/java/com/alibaba/csp/sentinel/demo/annotation/aop/controller/DemoController.java

@@ -19,6 +19,8 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
@@ -31,8 +33,16 @@ public class DemoController {
     private TestService service;
 
     @GetMapping("/foo")
-    public String foo() throws Exception {
+    public String apiFoo(@RequestParam(required = false) Long t) throws Exception {
+        if (t == null) {
+            t = System.currentTimeMillis();
+        }
         service.test();
-        return service.hello(System.currentTimeMillis());
+        return service.hello(t);
+    }
+
+    @GetMapping("/baz/{name}")
+    public String apiBaz(@PathVariable("name") String name) {
+        return service.helloAnother(name);
     }
 }

sentinel-demo/sentinel-demo-annotation-spring-aop/src/main/java/com/alibaba/csp/sentinel/demo/annotation/aop/service/ExceptionUtil.java

@@ -23,6 +23,12 @@
 public final class ExceptionUtil {
 
     public static void handleException(BlockException ex) {
+        // Handler method that handles BlockException when blocked.
+        // The method parameter list should match original method, with the last additional
+        // parameter with type BlockException. The return type should be same as the original method.
+        // The block handler method should be located in the same class with original method by default.
+        // If you want to use method in other classes, you can set the blockHandlerClass
+        // with corresponding Class (Note the method in other classes must be static).
         System.out.println("Oops: " + ex.getClass().getCanonicalName());
     }
 }

sentinel-demo/sentinel-demo-annotation-spring-aop/src/main/java/com/alibaba/csp/sentinel/demo/annotation/aop/service/TestService.java

@@ -23,4 +23,6 @@ public interface TestService {
     void test();
 
     String hello(long s);
+
+    String helloAnother(String name);
 }

sentinel-demo/sentinel-demo-annotation-spring-aop/src/main/java/com/alibaba/csp/sentinel/demo/annotation/aop/service/TestServiceImpl.java

@@ -33,14 +33,35 @@ public void test() {
     }
 
     @Override
-    @SentinelResource(value = "hello", blockHandler = "exceptionHandler")
+    @SentinelResource(value = "hello", fallback = "helloFallback")
     public String hello(long s) {
+        if (s < 0) {
+            throw new IllegalArgumentException("invalid arg");
+        }
         return String.format("Hello at %d", s);
     }
 
-    public String exceptionHandler(long s, BlockException ex) {
+    @Override
+    @SentinelResource(value = "helloAnother", defaultFallback = "defaultFallback",
+        exceptionsToIgnore = {IllegalStateException.class})
+    public String helloAnother(String name) {
+        if (name == null || "bad".equals(name)) {
+            throw new IllegalArgumentException("oops");
+        }
+        if ("foo".equals(name)) {
+            throw new IllegalStateException("oops");
+        }
+        return "Hello, " + name;
+    }
+
+    public String helloFallback(long s, Throwable ex) {
         // Do some log here.
         ex.printStackTrace();
         return "Oops, error occurred at " + s;
     }
+
+    public String defaultFallback() {
+        System.out.println("Go to default fallback");
+        return "default_fallback";
+    }
 }