Use Bean Validation (JSR 303) annotations for resolving JSON schema validation constraints

pom.xml

@@ -55,6 +55,11 @@ JSON Schema (http://tools.ietf.org/html/draft-zyp-json-schema-03) version 3 gene
       <artifactId>jackson-databind</artifactId>
       <version>${version.jackson.core}</version>
     </dependency>
+    <dependency>
+      <groupId>javax.validation</groupId>
+      <artifactId>validation-api</artifactId>
+      <version>1.1.0.Final</version>
+    </dependency>
 
   </dependencies>
   <build>

src/main/java/com/fasterxml/jackson/module/jsonSchema/customProperties/ValidationSchemaFactoryWrapper.java

@@ -0,0 +1,88 @@
+package com.fasterxml.jackson.module.jsonSchema.customProperties;
+
+import com.fasterxml.jackson.databind.BeanProperty;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor;
+import com.fasterxml.jackson.module.jsonSchema.JsonSchema;
+import com.fasterxml.jackson.module.jsonSchema.factories.*;
+import com.fasterxml.jackson.module.jsonSchema.types.ArraySchema;
+import com.fasterxml.jackson.module.jsonSchema.types.NumberSchema;
+import com.fasterxml.jackson.module.jsonSchema.types.ObjectSchema;
+import com.fasterxml.jackson.module.jsonSchema.types.StringSchema;
+import com.fasterxml.jackson.module.jsonSchema.validation.AnnotationConstraintResolver;
+import com.fasterxml.jackson.module.jsonSchema.validation.ValidationConstraintResolver;
+
+/**
+ * @author cponomaryov
+ */
+public class ValidationSchemaFactoryWrapper extends SchemaFactoryWrapper {
+
+    private ValidationConstraintResolver constraintResolver;
+
+    private static class ValidationSchemaFactoryWrapperFactory extends WrapperFactory {
+        @Override
+        public SchemaFactoryWrapper getWrapper(SerializerProvider p) {
+            SchemaFactoryWrapper wrapper = new ValidationSchemaFactoryWrapper();
+            wrapper.setProvider(p);
+            return wrapper;
+        }
+
+        @Override
+        public SchemaFactoryWrapper getWrapper(SerializerProvider p, VisitorContext rvc) {
+            SchemaFactoryWrapper wrapper = new ValidationSchemaFactoryWrapper();
+            wrapper.setProvider(p);
+            wrapper.setVisitorContext(rvc);
+            return wrapper;
+        }
+    }
+
+    public ValidationSchemaFactoryWrapper() {
+        this(new AnnotationConstraintResolver());
+    }
+
+    public ValidationSchemaFactoryWrapper(ValidationConstraintResolver constraintResolver) {
+        super(new ValidationSchemaFactoryWrapperFactory());
+        this.constraintResolver = constraintResolver;
+    }
+
+    @Override
+    public JsonObjectFormatVisitor expectObjectFormat(JavaType convertedType) {
+        return new ObjectVisitorDecorator((ObjectVisitor) super.expectObjectFormat(convertedType)) {
+            private JsonSchema getPropertySchema(BeanProperty writer) {
+                return ((ObjectSchema) getSchema()).getProperties().get(writer.getName());
+            }
+
+            @Override
+            public void optionalProperty(BeanProperty writer) throws JsonMappingException {
+                super.optionalProperty(writer);
+                addValidationConstraints(getPropertySchema(writer), writer);
+            }
+
+            @Override
+            public void property(BeanProperty writer) throws JsonMappingException {
+                super.property(writer);
+                addValidationConstraints(getPropertySchema(writer), writer);
+            }
+        };
+    }
+
+    private JsonSchema addValidationConstraints(JsonSchema schema, BeanProperty prop) {
+        if (schema.isArraySchema()) {
+            ArraySchema arraySchema = schema.asArraySchema();
+            arraySchema.setMaxItems(constraintResolver.getArrayMaxItems(prop));
+            arraySchema.setMinItems(constraintResolver.getArrayMinItems(prop));
+        } else if (schema.isNumberSchema()) {
+            NumberSchema numberSchema = schema.asNumberSchema();
+            numberSchema.setMaximum(constraintResolver.getNumberMaximum(prop));
+            numberSchema.setMinimum(constraintResolver.getNumberMinimum(prop));
+        } else if (schema.isStringSchema()) {
+            StringSchema stringSchema = schema.asStringSchema();
+            stringSchema.setMaxLength(constraintResolver.getStringMaxLength(prop));
+            stringSchema.setMinLength(constraintResolver.getStringMinLength(prop));
+        }
+        return schema;
+    }
+
+}

src/main/java/com/fasterxml/jackson/module/jsonSchema/factories/ObjectVisitorDecorator.java

@@ -0,0 +1,57 @@
+package com.fasterxml.jackson.module.jsonSchema.factories;
+
+import com.fasterxml.jackson.databind.BeanProperty;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitable;
+import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor;
+import com.fasterxml.jackson.module.jsonSchema.JsonSchema;
+
+/**
+ * @author cponomaryov
+ */
+public class ObjectVisitorDecorator implements JsonObjectFormatVisitor, JsonSchemaProducer {
+
+    protected ObjectVisitor objectVisitor;
+
+    public ObjectVisitorDecorator(ObjectVisitor objectVisitor) {
+        this.objectVisitor = objectVisitor;
+    }
+
+    @Override
+    public JsonSchema getSchema() {
+        return objectVisitor.getSchema();
+    }
+
+    @Override
+    public SerializerProvider getProvider() {
+        return objectVisitor.getProvider();
+    }
+
+    @Override
+    public void setProvider(SerializerProvider serializerProvider) {
+        objectVisitor.setProvider(serializerProvider);
+    }
+
+    @Override
+    public void optionalProperty(BeanProperty writer) throws JsonMappingException {
+        objectVisitor.optionalProperty(writer);
+    }
+
+    @Override
+    public void optionalProperty(String name, JsonFormatVisitable handler, JavaType propertyTypeHint) throws JsonMappingException {
+        objectVisitor.optionalProperty(name, handler, propertyTypeHint);
+    }
+
+    @Override
+    public void property(BeanProperty writer) throws JsonMappingException {
+        objectVisitor.property(writer);
+    }
+
+    @Override
+    public void property(String name, JsonFormatVisitable handler, JavaType propertyTypeHint) throws JsonMappingException {
+        objectVisitor.property(name, handler, propertyTypeHint);
+    }
+
+}

src/main/java/com/fasterxml/jackson/module/jsonSchema/validation/AnnotationConstraintResolver.java

@@ -0,0 +1,66 @@
+package com.fasterxml.jackson.module.jsonSchema.validation;
+
+import com.fasterxml.jackson.databind.BeanProperty;
+
+import javax.validation.constraints.*;
+import java.math.BigDecimal;
+
+/**
+ * @author cponomaryov
+ */
+public class AnnotationConstraintResolver implements ValidationConstraintResolver {
+
+    private Size getSizeAnnotation(BeanProperty prop) {
+        return prop.getAnnotation(Size.class);
+    }
+
+    private Integer getMaxSize(BeanProperty prop) {
+        Size sizeAnnotation = getSizeAnnotation(prop);
+        return sizeAnnotation != null && sizeAnnotation.max() != Integer.MAX_VALUE ? sizeAnnotation.max() : null;
+    }
+
+    private Integer getMinSize(BeanProperty prop) {
+        Size sizeAnnotation = getSizeAnnotation(prop);
+        return sizeAnnotation != null && sizeAnnotation.min() != 0 ? sizeAnnotation.min() : null;
+    }
+
+    @Override
+    public Integer getArrayMaxItems(BeanProperty prop) {
+        return getMaxSize(prop);
+    }
+
+    @Override
+    public Integer getArrayMinItems(BeanProperty prop) {
+        return getMinSize(prop);
+    }
+
+    @Override
+    public Double getNumberMaximum(BeanProperty prop) {
+        Max maxAnnotation = prop.getAnnotation(Max.class);
+        if (maxAnnotation != null) {
+            return (double) maxAnnotation.value();
+        }
+        DecimalMax decimalMaxAnnotation = prop.getAnnotation(DecimalMax.class);
+        return decimalMaxAnnotation != null ? new BigDecimal(decimalMaxAnnotation.value()).doubleValue() : null;
+    }
+
+    @Override
+    public Double getNumberMinimum(BeanProperty prop) {
+        Min minAnnotation = prop.getAnnotation(Min.class);
+        if (minAnnotation != null) {
+            return (double) minAnnotation.value();
+        }
+        DecimalMin decimalMinAnnotation = prop.getAnnotation(DecimalMin.class);
+        return decimalMinAnnotation != null ? new BigDecimal(decimalMinAnnotation.value()).doubleValue() : null;
+    }
+
+    @Override
+    public Integer getStringMaxLength(BeanProperty prop) {
+        return getMaxSize(prop);
+    }
+
+    @Override
+    public Integer getStringMinLength(BeanProperty prop) {
+        return getMinSize(prop);
+    }
+}

src/main/java/com/fasterxml/jackson/module/jsonSchema/validation/ValidationConstraintResolver.java

@@ -0,0 +1,22 @@
+package com.fasterxml.jackson.module.jsonSchema.validation;
+
+import com.fasterxml.jackson.databind.BeanProperty;
+
+/**
+ * @author cponomaryov
+ */
+public interface ValidationConstraintResolver {
+
+    Integer getArrayMaxItems(BeanProperty prop);
+
+    Integer getArrayMinItems(BeanProperty prop);
+
+    Double getNumberMaximum(BeanProperty prop);
+
+    Double getNumberMinimum(BeanProperty prop);
+
+    Integer getStringMaxLength(BeanProperty prop);
+
+    Integer getStringMinLength(BeanProperty prop);
+
+}