gracefully fail with unsupported HTTP methods

Author: tangiel

endpoints-framework/src/main/java/com/google/api/server/spi/dispatcher/HttpMethod.java

@@ -15,6 +15,9 @@
  */
 package com.google.api.server.spi.dispatcher;
 
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
+
 /**
  * Possible HTTP methods for use in the dispatcher.
  */
@@ -23,5 +26,22 @@ enum HttpMethod {
   POST,
   PUT,
   DELETE,
-  PATCH
+  PATCH;
+
+  private static final ImmutableMap<String, HttpMethod> STRING_TO_ENUM =
+      ImmutableMap.<String, HttpMethod>builder()
+          .put("GET", GET)
+          .put("POST", POST)
+          .put("PUT", PUT)
+          .put("DELETE", DELETE)
+          .put("PATCH", PATCH)
+          .build();
+
+  /**
+   * Returns an {@link HttpMethod} corresponding to a string value, or null if it doesn't exist.
+   */
+  public static HttpMethod fromString(String method) {
+    Preconditions.checkNotNull(method, "method");
+    return STRING_TO_ENUM.get(method.toUpperCase());
+  }
 }

endpoints-framework/src/main/java/com/google/api/server/spi/dispatcher/PathDispatcher.java

@@ -42,12 +42,14 @@ private PathDispatcher(Builder<ContextT> builder) {
   public boolean dispatch(String httpMethod, String path, ContextT context) throws IOException {
     Preconditions.checkNotNull(httpMethod, "httpMethod");
     Preconditions.checkNotNull(path, "path");
-    Result<DispatcherHandler<ContextT>> result =
-        trie.resolve(HttpMethod.valueOf(httpMethod.toUpperCase()), path);
-    if (result != null) {
-      context.setRawPathParameters(result.getRawParameters());
-      result.getResult().handle(context);
-      return true;
+    HttpMethod method = HttpMethod.fromString(httpMethod);
+    if (method != null) {
+      Result<DispatcherHandler<ContextT>> result = trie.resolve(method, path);
+      if (result != null) {
+        context.setRawPathParameters(result.getRawParameters());
+        result.getResult().handle(context);
+        return true;
+      }
     }
     return false;
   }

endpoints-framework/src/test/java/com/google/api/server/spi/dispatcher/PathDispatcherTest.java

@@ -121,4 +121,10 @@ public void builderNullHandler() {
       // expected
     }
   }
+
+  @Test
+  public void methodNotKnown() throws IOException {
+    PathDispatcher<DispatcherContext> dispatcher = PathDispatcher.builder().build();
+    assertThat(dispatcher.dispatch("INVALID", "test/one/two/3", context)).isFalse();
+  }
 }