Provide details when schema resource is invalid

spring-graphql/src/main/java/org/springframework/graphql/execution/DefaultGraphQlSourceBuilder.java

@@ -46,6 +46,7 @@
 import graphql.schema.idl.TypeDefinitionRegistry;
 import graphql.schema.idl.WiringFactory;
 
+import graphql.schema.idl.errors.SchemaProblem;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -184,7 +185,7 @@ private void registerDefaultTypeResolver(TypeDefinitionRegistry registry, Runtim
 
 	private TypeDefinitionRegistry parseSchemaResource(Resource schemaResource) {
 		Assert.notNull(schemaResource, "'schemaResource' not provided");
-		Assert.isTrue(schemaResource.exists(), "'schemaResource' does not exist");
+		Assert.isTrue(schemaResource.exists(), "'schemaResource' must exist: " + schemaResource);
 		try {
 			try (InputStream inputStream = schemaResource.getInputStream()) {
 				return new SchemaParser().parse(inputStream);
@@ -193,6 +194,9 @@ private TypeDefinitionRegistry parseSchemaResource(Resource schemaResource) {
 		catch (IOException ex) {
 			throw new IllegalArgumentException("Failed to load schema resource: " + schemaResource);
 		}
+		catch (SchemaProblem ex) {
+			throw new InvalidSchemaResourceException(schemaResource.getDescription(), ex);
+		}
 	}
 
 	private GraphQLSchema applyTypeVisitors(GraphQLSchema schema) {

spring-graphql/src/main/java/org/springframework/graphql/execution/InvalidSchemaResourceException.java

@@ -0,0 +1,44 @@
+package org.springframework.graphql.execution;
+
+import graphql.GraphQLException;
+import graphql.schema.idl.errors.SchemaProblem;
+
+
+/**
+ * Indicates that the Resource in {@link GraphQlSource.Builder} is invalid.
+ *
+ * @author GenKui Du
+ * @since 1.0.0
+ */
+public class InvalidSchemaResourceException extends GraphQLException {
+
+    private final String resourceDescription;
+
+    private final SchemaProblem schemaProblem;
+
+    public InvalidSchemaResourceException(String resourceDescription, SchemaProblem schemaProblem) {
+        super(
+                String.format("invalid schema, resource = %s, errors = %s", resourceDescription, schemaProblem.getErrors()),
+                schemaProblem
+        );
+        this.resourceDescription = resourceDescription;
+        this.schemaProblem = schemaProblem;
+    }
+
+    public String getResourceDescription() {
+        return resourceDescription;
+    }
+
+    public SchemaProblem getSchemaProblem() {
+        return schemaProblem;
+    }
+
+    @Override
+    public String toString() {
+        return "InvalidSchemaResourceException{" +
+                "resourceDescription='" + resourceDescription + '\'' +
+                ", schemaProblem=" + schemaProblem +
+                '}';
+    }
+
+}