Adding custom message support in the schema

src/main/java/com/networknt/schema/ErrorMessageType.java

@@ -35,4 +35,8 @@ public interface ErrorMessageType {
      */
     MessageFormat getMessageFormat();
 
+    default String getCustomMessage() {
+        return null;
+    }
+
 }

src/main/java/com/networknt/schema/FormatKeyword.java

@@ -68,4 +68,11 @@ public JsonValidator newValidator(String schemaPath, JsonNode schemaNode, JsonSc
     public String getValue() {
         return type.getValue();
     }
+
+    @Override
+    public void setCustomMessage(String message) {
+        type.setCustomMessage(message);
+    }
+
+
 }

src/main/java/com/networknt/schema/JsonMetaSchema.java

@@ -180,7 +180,8 @@ public static JsonMetaSchema getInstance() {
                             new NonValidationKeyword("$comment"),
                             new NonValidationKeyword("contentMediaType"),
                             new NonValidationKeyword("contentEncoding"),
-                            new NonValidationKeyword("examples")
+                            new NonValidationKeyword("examples"),
+                            new NonValidationKeyword("message")
                     ))
                     .build();
         }
@@ -374,8 +375,9 @@ public String getIdKeyword() {
         return idKeyword;
     }
 
+
     public JsonValidator newValidator(ValidationContext validationContext, String schemaPath, String keyword /* keyword */, JsonNode schemaNode,
-                                      JsonSchema parentSchema) {
+                                      JsonSchema parentSchema, String customMessage) {
 
         try {
             Keyword kw = keywords.get(keyword);
@@ -385,6 +387,7 @@ public JsonValidator newValidator(ValidationContext validationContext, String sc
                 }
                 return null;
             }
+            kw.setCustomMessage(customMessage);
             return kw.newValidator(schemaPath, schemaNode, parentSchema, validationContext);
         } catch (InvocationTargetException e) {
             if (e.getTargetException() instanceof JsonSchemaException) {

src/main/java/com/networknt/schema/JsonSchema.java

@@ -208,19 +208,21 @@ private Map<String, JsonValidator> read(JsonNode schemaNode) {
         Map<String, JsonValidator> validators = new HashMap<String, JsonValidator>();
         if (schemaNode.isBoolean()) {
             if (schemaNode.booleanValue()) {
-                JsonValidator validator = validationContext.newValidator(getSchemaPath(), "true", schemaNode, this);
+                final String customMessage = getCustomMessage(schemaNode, "true");
+                JsonValidator validator = validationContext.newValidator(getSchemaPath(), "true", schemaNode, this, customMessage);
                 validators.put(getSchemaPath() + "/true", validator);
             } else {
-                JsonValidator validator = validationContext.newValidator(getSchemaPath(), "false", schemaNode, this);
+                final String customMessage = getCustomMessage(schemaNode, "false");
+                JsonValidator validator = validationContext.newValidator(getSchemaPath(), "false", schemaNode, this, customMessage);
                 validators.put(getSchemaPath() + "/false", validator);
             }
         } else {
             Iterator<String> pnames = schemaNode.fieldNames();
             while (pnames.hasNext()) {
                 String pname = pnames.next();
                 JsonNode nodeToUse = pname.equals("if") ? schemaNode : schemaNode.get(pname);
-
-                JsonValidator validator = validationContext.newValidator(getSchemaPath(), pname, nodeToUse, this);
+                String customMessage = getCustomMessage(schemaNode, pname);
+                JsonValidator validator = validationContext.newValidator(getSchemaPath(), pname, nodeToUse, this, customMessage);
                 if (validator != null) {
                     validators.put(getSchemaPath() + "/" + pname, validator);
 
@@ -234,6 +236,24 @@ private Map<String, JsonValidator> read(JsonNode schemaNode) {
         return validators;
     }
 
+    private String getCustomMessage(JsonNode schemaNode, String pname) {
+        final JsonSchema parentSchema = getParentSchema();
+        final JsonNode message = getMessageNode(schemaNode, parentSchema);
+        if(message != null && message.get(pname) != null) {
+            return message.get(pname).asText();
+        }
+        return null;
+    }
+
+    private JsonNode getMessageNode(JsonNode schemaNode, JsonSchema parentSchema) {
+        JsonNode nodeContainingMessage;
+        if (parentSchema == null)
+            nodeContainingMessage  = schemaNode;
+        else
+            nodeContainingMessage = parentSchema.schemaNode;
+        return nodeContainingMessage.get("message");
+    }
+
     /************************ START OF VALIDATE METHODS **********************************/
 
     public Set<ValidationMessage> validate(JsonNode jsonNode, JsonNode rootNode, String at) {

src/main/java/com/networknt/schema/Keyword.java

@@ -22,5 +22,9 @@
 public interface Keyword {
     String getValue();
 
+    default void setCustomMessage(String message) {
+        //setCustom message
+    }
+
     JsonValidator newValidator(String schemaPath, JsonNode schemaNode, JsonSchema parentSchema, ValidationContext validationContext) throws JsonSchemaException, Exception;
 }

src/main/java/com/networknt/schema/ValidationContext.java

@@ -53,8 +53,8 @@ public ValidationContext(URIFactory uriFactory, URNFactory urnFactory, JsonMetaS
     }
 
     public JsonValidator newValidator(String schemaPath, String keyword /* keyword */, JsonNode schemaNode,
-                                      JsonSchema parentSchema) {
-        return metaSchema.newValidator(this, schemaPath, keyword, schemaNode, parentSchema);
+                                      JsonSchema parentSchema, String customMessage) {
+        return metaSchema.newValidator(this, schemaPath, keyword, schemaNode, parentSchema, customMessage);
     }
 
     public String resolveSchemaId(JsonNode schemaNode) {

src/main/java/com/networknt/schema/ValidationMessage.java

@@ -16,6 +16,8 @@
 
 package com.networknt.schema;
 
+import org.apache.commons.lang3.StringUtils;
+
 import java.text.MessageFormat;
 import java.util.Arrays;
 import java.util.Map;
@@ -114,7 +116,8 @@ public void setType(String type) {
     public static ValidationMessage of(String type, ErrorMessageType errorMessageType, String at, String... arguments) {
         ValidationMessage.Builder builder = new ValidationMessage.Builder();
         builder.code(errorMessageType.getErrorCode()).path(at).arguments(arguments)
-                .format(errorMessageType.getMessageFormat()).type(type);
+                .format(errorMessageType.getMessageFormat()).type(type)
+                .customMessage(errorMessageType.getCustomMessage());
         return builder.build();
     }
 
@@ -132,6 +135,7 @@ public static class Builder {
         private String[] arguments;
         private Map<String, Object> details;
         private MessageFormat format;
+        private String customMessage;
 
         public Builder type(String type) {
             this.type = type;
@@ -163,6 +167,11 @@ public Builder format(MessageFormat format) {
             return this;
         }
 
+        public Builder customMessage(String customMessage) {
+            this.customMessage = customMessage;
+            return this;
+        }
+
         public ValidationMessage build() {
             ValidationMessage msg = new ValidationMessage();
             msg.setType(type);
@@ -179,7 +188,12 @@ public ValidationMessage build() {
                         objs[i] = arguments[i - 1];
                     }
                 }
-                msg.setMessage(format.format(objs));
+                if(StringUtils.isNotBlank(customMessage)) {
+                    msg.setMessage(customMessage);
+                } else {
+                    msg.setMessage(format.format(objs));
+                }
+
             }
 
             return msg;

src/main/java/com/networknt/schema/ValidatorTypeCode.java

@@ -87,6 +87,7 @@ public JsonValidator newValidator(String schemaPath, JsonNode schemaNode, JsonSc
     private final String value;
     private final String errorCode;
     private final MessageFormat messageFormat;
+    private String customMessage;
     private final String errorCodeKey;
     private final Class validator;
     private final long versionCode;
@@ -99,6 +100,7 @@ private ValidatorTypeCode(String value, String errorCode, MessageFormat messageF
         this.errorCodeKey = value + "ErrorCode";
         this.validator = validator;
         this.versionCode = versionCode;
+        this.customMessage = null;
     }
 
     public static List<ValidatorTypeCode> getNonFormatKeywords(SpecVersion.VersionFlag versionFlag) {
@@ -148,6 +150,14 @@ public MessageFormat getMessageFormat() {
         return messageFormat;
     }
 
+    public void setCustomMessage(String message) {
+        this.customMessage = message;
+    }
+
+    public String getCustomMessage() {
+        return customMessage;
+    }
+
     public String getErrorCodeKey() {
         return errorCodeKey;
     }

src/test/java/com/networknt/schema/Issue426Test.java

@@ -0,0 +1,42 @@
+package com.networknt.schema;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.InputStream;
+import java.util.Set;
+
+/**
+ * Validating custom message
+ */
+public class Issue426Test {
+    protected JsonSchema getJsonSchemaFromStreamContentV7(InputStream schemaContent) {
+        JsonSchemaFactory factory = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V7);
+        return factory.getSchema(schemaContent);
+    }
+
+    protected JsonNode getJsonNodeFromStreamContent(InputStream content) throws Exception {
+        ObjectMapper mapper = new ObjectMapper();
+        return mapper.readTree(content);
+    }
+
+    @Test
+    public void shouldWorkV7() throws Exception {
+        String schemaPath = "/schema/issue426-v7.json";
+        String dataPath = "/data/issue426.json";
+        InputStream schemaInputStream = getClass().getResourceAsStream(schemaPath);
+        JsonSchema schema = getJsonSchemaFromStreamContentV7(schemaInputStream);
+        InputStream dataInputStream = getClass().getResourceAsStream(dataPath);
+        JsonNode node = getJsonNodeFromStreamContent(dataInputStream);
+        Set<ValidationMessage> errors = schema.validate(node);
+        Assert.assertEquals(2, errors.size());
+        final JsonNode message = schema.schemaNode.get("message");
+        for(ValidationMessage error : errors) {
+            //validating custom message
+            Assert.assertEquals(message.get(error.getType()).asText(),  error.getMessage());
+        }
+    }
+}
+

src/test/resources/data/issue426.json

@@ -0,0 +1,9 @@
+{
+  "firstName": {},
+  "foo": [
+    1,
+    2,
+    3,
+    4
+  ]
+}

src/test/resources/schema/issue426-v7.json

@@ -0,0 +1,20 @@
+{
+  "$id": "https://example.com/person.schema.json",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "Person",
+  "type": "object",
+  "properties": {
+    "firstName": {
+      "type": "string",
+      "description": "The person's first name."
+    },
+    "foo": {
+      "type": "array",
+      "maxItems": 3
+    }
+  },
+  "message": {
+    "maxItems" : "MaxItem must be 3 only",
+    "type" : "Invalid type"
+  }
+}