com.trenako.web.images.MultipartFileValidator.java Source code

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Here is the source code for com.trenako.web.images.MultipartFileValidator.java

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/*
 * Copyright 2012 the original author or authors.
 * 
 * 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 com.trenako.web.images;

import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;
import org.springframework.web.multipart.MultipartFile;

import com.trenako.AppGlobals;

/**
 * A custom validator for {@code MultipartFile}.
 * <p>
 * Validation is checking the {@code size} and {@code contentType}
 * for the uploaded file. Validation for empty files will always succeeds.
 * </p>
 *
 * @author Carlo Micieli
 */
@Component
public class MultipartFileValidator implements Validator {
    @Override
    public boolean supports(Class<?> clazz) {
        return MultipartFile.class.isAssignableFrom(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        // skip validation for empty files.
        if (target == null)
            return;

        MultipartFile file = (MultipartFile) target;
        if (file.isEmpty())
            return;

        // validate file size
        if (file.getSize() > AppGlobals.MAX_UPLOAD_SIZE) {
            errors.reject("uploadFile.size.range.notmet", "Invalid media size. Max size is 512 Kb");
        }

        // validate content type
        MediaType contentType = MediaType.parseMediaType(file.getContentType());
        if (!AppGlobals.ALLOWED_MEDIA_TYPES.contains(contentType.toString())) {
            errors.reject("uploadFile.contentType.notvalid", "Invalid media type");
        }
    }
}