SHA-1 Calculator FXML (JavaFX+FXML) / http://inaz2.hatenablog.com/entry/2016/04/26/203503

FileInfo.java

package application;

import javafx.beans.property.SimpleStringProperty;

public class FileInfo {
	private final SimpleStringProperty path = new SimpleStringProperty();
	private final SimpleStringProperty sha1sum = new SimpleStringProperty();

	public FileInfo(String path, String sha1sum) {
		setPath(path);
		setSha1sum(sha1sum);
	}

	public String getPath() {
		return path.get();
	}

	public void setPath(String newPath) {
		path.set(newPath);
	}

	public String getSha1sum() {
		return sha1sum.get();
	}

	public void setSha1sum(String newSha1sum) {
		sha1sum.set(newSha1sum);
	}

	public SimpleStringProperty sha1sumProperty() {
		return sha1sum;
	}
}

Main.java

package application;
	
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.fxml.FXMLLoader;


public class Main extends Application {
	@Override
	public void start(Stage primaryStage) {
		try {
			primaryStage.setTitle("SHA-1 Calculator FXML");
			
			BorderPane root = (BorderPane)FXMLLoader.load(getClass().getResource("MainWindow.fxml"));
			Scene scene = new Scene(root,600,400);  // expanded default size
			scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
			primaryStage.setScene(scene);
			primaryStage.show();
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) {
		launch(args);
	}
}

MainWindow.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.collections.FXCollections?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.cell.PropertyValueFactory?>
<?import javafx.scene.layout.BorderPane?>

<BorderPane xmlns="http://javafx.com/javafx/8.0.65" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.MainWindowController">
	<center>
		<TableView fx:id="tableView" editable="true" onDragDropped="#handleDragDropped" onDragOver="#handleDragOver">
			<columnResizePolicy>
				<TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
			</columnResizePolicy>
			<columns>
				<TableColumn fx:id="filePathCol" text="File Path">
					<cellValueFactory><PropertyValueFactory property="path" /></cellValueFactory>
				</TableColumn>
				<TableColumn fx:id="sha1sumCol" text="sha1sum">
					<cellValueFactory><PropertyValueFactory property="sha1sum" /></cellValueFactory>
				</TableColumn>
			</columns>
			<items>
				<FXCollections fx:factory="observableArrayList" />
			</items>
		</TableView>
	</center>
</BorderPane>

MainWindowController.java

package application;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

import javafx.collections.ObservableList;
import javafx.concurrent.Task;
import javafx.fxml.FXML;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.TransferMode;

public class MainWindowController {
	@FXML private TableView<FileInfo> tableView;
	@FXML private TableColumn<FileInfo, String> filePathCol;
	@FXML private TableColumn<FileInfo, String> sha1sumCol;

	@FXML private void initialize() {
		filePathCol.setCellFactory(TextFieldTableCell.forTableColumn());
		sha1sumCol.setCellFactory(TextFieldTableCell.forTableColumn());
	}
	
	public void handleDragOver(DragEvent event) {
		Dragboard db = event.getDragboard();
		if (db.hasFiles()) {
			event.acceptTransferModes(TransferMode.COPY);
		} else {
			event.consume();
		}
	}

	public void handleDragDropped(DragEvent event) {
		ObservableList<FileInfo> data = tableView.getItems();
		Dragboard db = event.getDragboard();
		boolean success = false;
		if (db.hasFiles()) {
			success = true;
			for (File file : db.getFiles()) {
				FileInfo fileinfo = new FileInfo(file.getAbsolutePath(), "");
				data.add(fileinfo);
				SHA1CalculationTask task = new SHA1CalculationTask(fileinfo);
				fileinfo.sha1sumProperty().bind(task.messageProperty());
				new Thread(task).start();
			}
		}
		event.setDropCompleted(success);
		event.consume();
	}

	class SHA1CalculationTask extends Task<Void> {
		private final FileInfo fileinfo;

		public SHA1CalculationTask(FileInfo fileinfo) {
			this.fileinfo = fileinfo;
		}

		@Override
		protected Void call() throws Exception {
			MessageDigest md = null;
			try {
				md = MessageDigest.getInstance("SHA-1");
			} catch (NoSuchAlgorithmException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			// update digest with each 8MB chunk
			String path = fileinfo.getPath();
			long totalBytes = (new File(path)).length();
			long currentBytes = 0;
			try (FileInputStream istream = new FileInputStream(path)) {
				byte[] buf = new byte[8*1024*1024];
				int n;
				while ((n = istream.read(buf, 0, buf.length)) != -1) {
					md.update(Arrays.copyOf(buf, n));
					currentBytes += n;
					String message = String.format("calculating %d%%...", 100 * currentBytes / totalBytes);
					updateMessage(message);
				}
			} catch (IOException e) {
				e.printStackTrace();
			}

			byte[] digest = md.digest();
			StringBuilder sb = new StringBuilder();
			for (byte b : digest) {
				sb.append(String.format("%02x", b));
			}
			updateMessage(sb.toString());
			return null;
		}
	}
}