FileUploadSizeValidator.java

package fr.openwide.core.wicket.more.util.validate.validators;

import java.util.List;

import org.apache.wicket.markup.html.form.FormComponent;
import org.apache.wicket.markup.html.form.upload.FileUpload;
import org.apache.wicket.util.lang.Bytes;
import org.apache.wicket.validation.IValidatable;
import org.apache.wicket.validation.IValidator;
import org.apache.wicket.validation.ValidationError;

/**
 * Checks that, for each uploaded file, the file size is smaller than or equal to a maximum expected size. 
 * 
 * <p>
 * Resource key: {@code <class.simpleName>}
 * </p>
 * 
 * <p>
 * Error Message Variables:
 * <ul>
 * <li>the default variables (see {@link FormComponent})</li>
 * <li>{@code maximum}: the maximum allowed value (as a {@link Bytes} object - see {@link BytesConverter} to display)</li>
 * <li>{@code clientFileName}: the name of the invalid file</li>
 * <li>{@code size}: the size of the invalid file (as a {@link Bytes} object - see {@link BytesConverter} to display)</li>
 * </ul>
 * </p>
 */
public class FileUploadSizeValidator implements IValidator<List<FileUpload>> {
	
	private static final long serialVersionUID = 3922765020138195477L;
	
	protected final Bytes maximum;
	
	private String errorResourceKey;
	
	public FileUploadSizeValidator(Bytes maximum) {
		this.maximum = maximum;
	}
	
	/**
	 * Allows subclasses to decorate reported errors
	 * 
	 * @param error
	 * @param validatable
	 * @return decorated error
	 */
	protected ValidationError decorate(ValidationError error, IValidatable<List<FileUpload>> validatable) {
		return error;
	}

	@Override
	public void validate(IValidatable<List<FileUpload>> validatable) {
		for (FileUpload fileUpload : validatable.getValue()) {
			Bytes fileSize = Bytes.bytes(fileUpload.getSize());
			if (fileSize.greaterThan(maximum)) {
				ValidationError error = new ValidationError();
				if (errorResourceKey != null) {
					error.addKey(errorResourceKey);
				}
				error.addKey(this);
				error.setVariable("maximum", maximum);
				error.setVariable("clientFileName", fileUpload.getClientFileName());
				error.setVariable("size", fileSize);
				validatable.error(error);
			}
		}
	}

	public FileUploadSizeValidator setErrorResourceKey(String errorResourceKey) {
		this.errorResourceKey = errorResourceKey;
		return this;
	}

}