CustomJackson2HttpMessageConverter.java

/*
 * Copyright 2026 Global Crop Diversity Trust
 * Licensed under the Apache License, Version 2.0
 * See LICENSE file in project root folder or http://www.apache.org/licenses/LICENSE-2.0
 */

package org.gringlobal.custom.json.converter;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;

import org.gringlobal.custom.json.IgnoreEntityRefHttpMessage;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageConversionException;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.util.StreamUtils;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
import org.jetbrains.annotations.NotNull;

public class CustomJackson2HttpMessageConverter extends MappingJackson2HttpMessageConverter {

	private final ObjectMapper defaultObjectMapper;

	public CustomJackson2HttpMessageConverter(ObjectMapper defaultObjectMapper) {
		super();
		this.defaultObjectMapper = defaultObjectMapper;
	}

	@Override
	@NotNull public Object read(@NotNull Type type, Class<?> contextClass, @NotNull HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
		if (inputMessage instanceof IgnoreEntityRefHttpMessage) {
			JavaType javaType = getJavaType(type, contextClass);
			return readJavaType(javaType, inputMessage);
		}
		return super.read(type, contextClass, inputMessage);
	}

	private Object readJavaType(JavaType javaType, HttpInputMessage inputMessage) throws IOException {
		try {
			InputStream inputStream = StreamUtils.nonClosing(inputMessage.getBody());
			return defaultObjectMapper.readValue(inputStream, javaType);
		}
		catch (InvalidDefinitionException ex) {
			throw new HttpMessageConversionException("Type definition error: " + ex.getType(), ex);
		}
		catch (JsonProcessingException ex) {
			throw new HttpMessageNotReadableException("JSON parse error: " + ex.getOriginalMessage(), ex, inputMessage);
		}
	}
}