fix: apply json schema validation correctly

src/main/java/edu/kit/datamanager/pit/typeregistry/AttributeInfo.java

@@ -3,6 +3,7 @@
 import edu.kit.datamanager.pit.typeregistry.schema.SchemaInfo;
 import org.everit.json.schema.Schema;
 import org.everit.json.schema.ValidationException;
+import org.json.JSONObject;
 
 import java.util.Collection;
 import java.util.Objects;
@@ -29,8 +30,12 @@ public boolean validate(String value) {
     }
 
     private boolean validate(Schema schema, String value) {
+        Object toValidate = value;
+        if (value.startsWith("{")) {
+            toValidate = new JSONObject(value);
+        }
         try {
-            schema.validate(value);
+            schema.validate(toValidate);
         } catch (ValidationException e) {
             return false;
         }

src/main/java/edu/kit/datamanager/pit/typeregistry/schema/SchemaSetGenerator.java

@@ -12,8 +12,8 @@
 import java.util.stream.Collectors;
 
 public class SchemaSetGenerator {
-    private final Set<SchemaGenerator> GENERATORS;
-    private final AsyncLoadingCache<String, Set<SchemaInfo>> CACHE;
+    protected final Set<SchemaGenerator> GENERATORS;
+    protected final AsyncLoadingCache<String, Set<SchemaInfo>> CACHE;
 
     public SchemaSetGenerator(ApplicationProperties props) {
         GENERATORS = Set.of(

src/test/java/edu/kit/datamanager/pit/typeregistry/schema/SchemaSetGeneratorTest.java

@@ -0,0 +1,46 @@
+package edu.kit.datamanager.pit.typeregistry.schema;
+
+import edu.kit.datamanager.pit.configuration.ApplicationProperties;
+import edu.kit.datamanager.pit.typeregistry.AttributeInfo;
+import org.everit.json.schema.Schema;
+import org.everit.json.schema.ValidationException;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.net.URI;
+import java.util.NoSuchElementException;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SchemaSetGeneratorTest {
+
+    static ApplicationProperties properties;
+    static SchemaSetGenerator generator;
+
+    @BeforeAll
+    static void setup() throws Exception {
+        properties = new ApplicationProperties();
+        properties.setExpireAfterWrite(10);
+        properties.setMaximumSize(1000);
+        properties.setTypeRegistryUri(new URI("https://typeapi.lab.pidconsortium.net").toURL());
+        properties.setHandleBaseUri(new URI("https://hdl.handle.net").toURL());
+        generator = new SchemaSetGenerator(properties);
+    }
+
+    /**
+     * @throws ValidationException if a schema fails to validate
+     * @throws NoSuchElementException if no schema is found
+     */
+    @Test
+    void testChecksumValidation() throws ValidationException, NoSuchElementException {
+        // generated test for this error message: Reason:\nAttribute 21.T11148/92e200311a56800b3e47 has a non-complying value { \"sha256sum\": \"sha256 c50624fd5ddd2b9652b72e2d2eabcb31a54b777718ab6fb7e44b582c20239a7c\" }
+        Set<SchemaInfo> schemaInfos = generator.generateFor("21.T11148/92e200311a56800b3e47").join();
+        AttributeInfo attributeInfo = new AttributeInfo("21.T11148/92e200311a56800b3e47", "name", "typeName", schemaInfos);
+        assertTrue(attributeInfo.validate("{ \"sha256sum\": \"sha256 c50624fd5ddd2b9652b72e2d2eabcb31a54b777718ab6fb7e44b582c20239a7c\" }"));
+        // This is currently not supported, but would be nice to have:
+        assertFalse(attributeInfo.validate("\"sha256 c50624fd5ddd2b9652b72e2d2eabcb31a54b777718ab6fb7e44b582c20239a7c\""));
+    }
+}