improved REST-API error handling for broken request body JSON

src/main/java/net/hostsharing/hsadminng/config/JsonObjectMapperConfiguration.java

@@ -1,5 +1,6 @@
 package net.hostsharing.hsadminng.config;
 
+import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import org.openapitools.jackson.nullable.JsonNullableModule;
@@ -16,6 +17,7 @@ public class JsonObjectMapperConfiguration {
     public Jackson2ObjectMapperBuilder customObjectMapper() {
         return new Jackson2ObjectMapperBuilder()
                 .modules(new JsonNullableModule(), new JavaTimeModule())
+                .featuresToEnable(JsonParser.Feature.ALLOW_COMMENTS)
                 .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
     }
 }

src/main/java/net/hostsharing/hsadminng/errors/CustomErrorResponse.java

@@ -0,0 +1,51 @@
+package net.hostsharing.hsadminng.errors;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.context.request.WebRequest;
+
+import java.time.LocalDateTime;
+
+@Getter
+class CustomErrorResponse {
+
+    static ResponseEntity<CustomErrorResponse> errorResponse(
+            final WebRequest request,
+            final HttpStatus httpStatus,
+            final String message) {
+        return new ResponseEntity<>(
+                new CustomErrorResponse(request.getContextPath(), httpStatus, message), httpStatus);
+    }
+
+    static String firstMessageLine(final Throwable exception) {
+        if (exception.getMessage() != null) {
+            return firstLine(exception.getMessage());
+        }
+        return "ERROR: [500] " + exception.getClass().getName();
+    }
+
+    static String firstLine(final String message) {
+        return message.split("\\r|\\n|\\r\\n", 0)[0];
+    }
+
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss")
+    private final LocalDateTime timestamp;
+
+    private final String path;
+
+    private final int status;
+
+    private final String error;
+
+    private final String message;
+
+    CustomErrorResponse(final String path, final HttpStatus status, final String message) {
+        this.timestamp = LocalDateTime.now();
+        this.path = path;
+        this.status = status.value();
+        this.error = status.getReasonPhrase();
+        this.message = message;
+    }
+}

src/main/java/net/hostsharing/hsadminng/errors/RestResponseEntityExceptionHandler.java

@@ -1,13 +1,12 @@
 package net.hostsharing.hsadminng.errors;
 
-import com.fasterxml.jackson.annotation.JsonFormat;
-import lombok.Getter;
 import org.iban4j.Iban4jException;
 import org.springframework.core.NestedExceptionUtils;
 import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.lang.Nullable;
 import org.springframework.orm.jpa.JpaObjectRetrievalFailureException;
 import org.springframework.orm.jpa.JpaSystemException;
 import org.springframework.web.bind.MethodArgumentNotValidException;
@@ -17,11 +16,12 @@ import org.springframework.web.context.request.WebRequest;
 import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
 
 import javax.persistence.EntityNotFoundException;
-import java.time.LocalDateTime;
 import java.util.NoSuchElementException;
 import java.util.Optional;
 import java.util.regex.Pattern;
 
+import static net.hostsharing.hsadminng.errors.CustomErrorResponse.*;
+
 @ControllerAdvice
 public class RestResponseEntityExceptionHandler
         extends ResponseEntityExceptionHandler {
@@ -73,6 +73,16 @@ public class RestResponseEntityExceptionHandler
 
     @Override
     @SuppressWarnings("unchecked,rawtypes")
+    protected ResponseEntity handleExceptionInternal(
+            Exception exc, @Nullable Object body, HttpHeaders headers, HttpStatus status, WebRequest request) {
+
+        final var response = super.handleExceptionInternal(exc, body, headers, status, request);
+        return errorResponse(request, response.getStatusCode(),
+                Optional.ofNullable(response.getBody()).map(Object::toString).orElse(firstMessageLine(exc)));
+    }
+
+    //@ExceptionHandler({ MethodArgumentNotValidException.class })
+    @SuppressWarnings("unchecked,rawtypes")
     protected ResponseEntity handleMethodArgumentNotValid(
             MethodArgumentNotValidException exc,
             HttpHeaders headers,
@@ -126,45 +136,4 @@ public class RestResponseEntityExceptionHandler
         return Optional.empty();
     }
 
-    private static ResponseEntity<CustomErrorResponse> errorResponse(
-            final WebRequest request,
-            final HttpStatus httpStatus,
-            final String message) {
-        return new ResponseEntity<>(
-                new CustomErrorResponse(request.getContextPath(), httpStatus, message), httpStatus);
-    }
-
-    private String firstMessageLine(final Throwable exception) {
-        if (exception.getMessage() != null) {
-            return firstLine(exception.getMessage());
-        }
-        return "ERROR: [500] " + exception.getClass().getName();
-    }
-
-    private String firstLine(final String message) {
-        return message.split("\\r|\\n|\\r\\n", 0)[0];
-    }
-}
-
-@Getter
-class CustomErrorResponse {
-
-    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss")
-    private final LocalDateTime timestamp;
-
-    private final String path;
-
-    private final int status;
-
-    private final String error;
-
-    private final String message;
-
-    public CustomErrorResponse(final String path, final HttpStatus status, final String message) {
-        this.timestamp = LocalDateTime.now();
-        this.path = path;
-        this.status = status.value();
-        this.error = status.getReasonPhrase();
-        this.message = message;
-    }
 }

src/test/java/net/hostsharing/hsadminng/hs/office/bankaccount/HsOfficeBankAccountControllerAcceptanceTest.java

@@ -136,7 +136,7 @@ class HsOfficeBankAccountControllerAcceptanceTest {
                         .port(port)
                     .when()
                         .post("http://localhost/api/hs/office/bankaccounts")
-                    .then().assertThat()
+                    .then().log().all().assertThat()
                         .statusCode(201)
                         .contentType(ContentType.JSON)
                         .body("uuid", isUuidValid())
@@ -346,7 +346,10 @@ class HsOfficeBankAccountControllerAcceptanceTest {
         jpaAttempt.transacted(() -> {
             context.define("superuser-alex@hostsharing.net", null);
             tempBankAccountUuids.addAll(
-              bankAccountRepo.findByOptionalHolderLike("some temp acc").stream().map(HsOfficeBankAccountEntity::getUuid).toList()
+                    bankAccountRepo.findByOptionalHolderLike("some temp acc")
+                            .stream()
+                            .map(HsOfficeBankAccountEntity::getUuid)
+                            .toList()
             );
         });
         tempBankAccountUuids.forEach(uuid -> {

src/test/java/net/hostsharing/hsadminng/test/cust/TestCustomerControllerAcceptanceTest.java

@@ -247,6 +247,26 @@ class TestCustomerControllerAcceptanceTest {
             context.define("superuser-fran@hostsharing.net");
             assertThat(testCustomerRepository.findCustomerByOptionalPrefixLike("uuu")).hasSize(0);
         }
+
+        @Test
+        void invalidRequestBodyJson_raisesClientError() {
+
+            RestAssured // @formatter:off
+                .given()
+                    .header("current-user", "superuser-alex@hostsharing.net")
+                    .contentType(ContentType.JSON)
+                    .body("{]") // deliberately invalid JSON
+                    .port(port)
+                .when()
+                    .post("http://localhost/api/test/customers")
+                .then().assertThat()
+                    .statusCode(400)
+                    .contentType(ContentType.JSON)
+                    .body("message", containsString("JSON parse error: Unexpected close marker ']': expected '}'"))
+                    .body("message", containsString("line: 1, column: 1"));
+            // @formatter:on
+        }
+
     }
 
     private UUID toCleanup(final UUID tempPartnerUuid) {
@@ -262,7 +282,9 @@ class TestCustomerControllerAcceptanceTest {
                 System.out.println("DELETING temporary partner: " + uuid);
                 final var entity = testCustomerRepository.findByUuid(uuid);
                 final var count = testCustomerRepository.deleteByUuid(uuid);
-                System.out.println("DELETED temporary partner: " + uuid + (count > 0 ? " successful" : " failed") + " (" + entity.map(TestCustomerEntity::getPrefix).orElse("???") + ")");
+                System.out.println(
+                        "DELETED temporary partner: " + uuid + (count > 0 ? " successful" : " failed") + " (" + entity.map(
+                                TestCustomerEntity::getPrefix).orElse("???") + ")");
             }).assertSuccessful();
         });
     }