EchoService.java

/*
 * Copyright (c) 2007-2026 MetaSolutions AB
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.entrystore.rest.springboot.service;

import lombok.RequiredArgsConstructor;
import org.entrystore.rest.springboot.configuration.EchoProperties;
import org.entrystore.rest.springboot.model.exception.TextareaHtmlResponseException;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.nio.charset.StandardCharsets;

@Service
@RequiredArgsConstructor
public class EchoService {

	private final EchoProperties echoProperties;

	public String readFileContentsAsString(MultipartFile file) {

		// We don't echo payloads bigger than the configured cap
		long maxFileSize = echoProperties.maxFileSize().toBytes();
		if (file.getSize() > maxFileSize) {
			throw new TextareaHtmlResponseException("Received file size (of " + file.getSize()
					+ "B) exceeds maximum allowed size of: " + maxFileSize + "B", HttpStatus.PAYLOAD_TOO_LARGE);
		}

		try {
			return file.getResource().getContentAsString(StandardCharsets.UTF_8);
		} catch (IOException e) {
			throw new TextareaHtmlResponseException("Unable to read file content", HttpStatus.BAD_REQUEST, e);
		}
	}
}