Copy SSH private key to Termux

Thu, 22 Aug 2024 08:40:10 +0200

Termux is a beautiful terminal emulator Android app. As I am working mostly on the command line I wanted to be able to do the same on phone. And most importantly in a case of emergency where I don’t have access to my computer I want to able to access my servers and run some commands. This requires to setup existing SSH private keys in the Termux.

I haven’t found a good tutorial that explains how to do this. It’s actually very easy.

First you need to able to access your private key file from your phone. In my case I uploaded the file id_ed25519 to my private Nextcloud. On my phone I access the file and choose Termux to open the file.

Termux then shows this dialog:

You choose Open Directory. The file is saved in ~/download.

Before we move the file to the correct location. Make sure that you have installed the openssh package.

apt update && apt upgrade
pkg install openssh

This will create the ssh folder in your home directory and provide the ssh command.

You can then move the file.

Now you can access your server using the private ssh key.

Note that you cannot change the username in Termux and therefore need to provide the username on the server in the ssh command.

Build a Java 3-tier application from scratch – Part 6: Client view

Thu, 02 Apr 2015 07:13:31 +0000

Welcome to the final part of my tutorial. In this last part we are going to write our view and run the client application.

The client application consists of a login and a data pane. When you’ve successfully logged in, the visibility of these panes will be switched. That’s all you have to know. In case you want to use scene builder to create the client GUI here’s a picture of what you have to build:

View

If you’re too lazy simply copy the fxml definitions.

Update the Home fxml markup file.

Home.fxml

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

<?import javafx.scene.image.*?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.paint.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.text.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="342.0" prefWidth="528.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.issueman.client.HomeView">
   <effect>
      <Glow />
   </effect>
   <children>
      <Pane fx:id="pnData" prefHeight="342.0" prefWidth="528.0" visible="false">
         <children>
            <TableView fx:id="tvEmployer" onMouseClicked="#clickTableView" prefHeight="342.0" prefWidth="317.0">
               <columns>
                  <TableColumn fx:id="tcId" prefWidth="50.0" text="ID" />
                  <TableColumn fx:id="tcName" prefWidth="135.0" text="Name" />
                  <TableColumn fx:id="tcCompany" prefWidth="131.0" text="Company" />
               </columns>
            </TableView>
            <TextField fx:id="txName" layoutX="327.0" layoutY="83.0" />
            <TextField fx:id="txCompany" layoutX="327.0" layoutY="127.0" />
            <Button fx:id="btAdd" layoutX="327.0" layoutY="171.0" mnemonicParsing="false" onAction="#clickAdd" text="Add" />
            <Button fx:id="btUpdate" layoutX="374.0" layoutY="171.0" mnemonicParsing="false" onAction="#clickUpdate" text="Update" />
            <Button fx:id="btDelete" layoutX="443.0" layoutY="171.0" mnemonicParsing="false" onAction="#clickDelete" text="Delete" />
         </children>
      </Pane>
      <Pane fx:id="pnLogin" prefHeight="342.0" prefWidth="528.0">
         <children>
            <TextField fx:id="txUsername" layoutX="171.0" layoutY="104.0" />
            <PasswordField fx:id="pfPassword" layoutX="171.0" layoutY="140.0" />
            <Button fx:id="btLogin" layoutX="236.0" layoutY="190.0" mnemonicParsing="false" onAction="#clickLogin" text="Login" />
         </children>
      </Pane>
   </children>
</AnchorPane>

Every view requires a controller, see there fx:controller="ch.issueman.client.HomeView". I’ve called this controller <view name>View.java in order to avoid using the word controller too much.

Upate the view handler.

HomeView.java

package ch.issueman.client;

import java.net.URL;
import java.util.ResourceBundle;

import javafx.collections.FXCollections;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.Pane;
import ch.issueman.common.Employer;
import ch.issueman.common.User;

public class HomeView implements Initializable {

	private static Controller<Employer, Integer> controller = new Controller<Employer, Integer>(Employer.class, null);

	@FXML
	private Button btAdd;

	@FXML
	private Button btUpdate;

	@FXML
	private Button btDelete;

	@FXML
	private Button btLogin;
	
	@FXML
	private Pane pnLogin;
	
	@FXML
	private Pane pnData;
	
	@FXML
	private TextField txUsername;
	
	@FXML
	private TextField txName;
	
	@FXML
	private TextField txCompany;
	
	@FXML
	private PasswordField pfPassword;
	
	@FXML
	private TableView<Employer> tvEmployer;

	@FXML
	private TableColumn<Employer, Integer> tcId;

	@FXML
	private TableColumn<Employer, String> tcName;
	
	@FXML
	private TableColumn<Employer, String> tcCompany;
	
	public void initialize(URL arg0, ResourceBundle arg1) {
		tcId.setCellValueFactory(new PropertyValueFactory<Employer, Integer>("id"));
		tcName.setCellValueFactory(new PropertyValueFactory<Employer, String>("name"));
		tcCompany.setCellValueFactory(new PropertyValueFactory<Employer, String>("company"));
		refreshPersonTable();
	}

	public void refreshPersonTable() {
		tvEmployer.setItems(FXCollections.observableArrayList(controller.getAll()));
	}

	@FXML
	public void clickTableView() {
		Employer e = tvEmployer.getSelectionModel().getSelectedItem();
		txName.textProperty().set(e.getName());
		txCompany.textProperty().set(e.getCompany());
	}

	@FXML
	public void clickAdd() {
		controller.persist(new Employer(txName.getText(), txCompany.getText()));
		refreshPersonTable();
	}

	@FXML
	public void clickUpdate() {
		Employer e = tvEmployer.getSelectionModel().getSelectedItem();
		e.setName(txName.getText());
		e.setCompany(txCompany.getText());
		controller.update(e);
		refreshPersonTable();
	}

	@FXML
	public void clickDelete() {
		Employer e = tvEmployer.getSelectionModel().getSelectedItem();
		controller.delete(e);
		refreshPersonTable();
	}
	
	@FXML
	public void clickLogin(){
		User user = new User("", txUsername.getText(), pfPassword.getText(), "");
		controller = new Controller<Employer, Integer>(Employer.class, user);
		if(controller.login()){
			pnData.setVisible(true);
			pnLogin.setVisible(false);
		}else{
			txUsername.setText("");
			pfPassword.setText("");
		}
	}
}

Make sure that you understand this class, it’s not that difficult. Every GUI components is connected to variables and every action (click, focus, etc.) requires a method in the view handler.

Finally open the command line.

Navigate to the project directory: cd <project>
Start the webservice: gradle jettyRun
Run the App.java file within eclipse.
Open the browser on http://localhost:8080/webservice/user copy the login data from one of the users and login in with your client.

If you did everything right you should see the employer entities.

Congratulations :D in case you got this far you are a professional Java developer from now on.

Thanks for joining and a nice feedback in comments section.

Download Code

You can download the project from here: https://codeberg.org/janikvonrotz/issue-manager/releases/tag/v2.2

3-Tier on Janik von Rotz

Copy SSH private key to Termux

Build a Java 3-tier application from scratch – Part 6: Client view

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