JustDoIt

Just do it

To-do management application for java. School project for the lecture web -based database applications at DHBW Karlsruhe.

Brief description

This is an example of a server-side MVC web application realized in Java. The application sets up on the "Jakarta Enterprise Edition" (formerly "Java Enterprise Edition") and therefore runs in a specially designed application server. All application logic is implemented by the server, so that a completely server-generated HTML page is called up for each URL pattern of the application and displayed in the browser.

Notes on the deployment

Used technologies

During the development we used a specially configured Tomee server. The derby database was used as a database. Both are contained in our files that are uploaded to the project delivery. The app uses Maven as a build tool and package management. In this way, the APIs necessary for Jakarta, but no further dependencies, are integrated into the project. The source code of the application is structured as follows:

• Servlets serve as a controller layer and receive all HTTP inquiries.
• Enterprise Java Beans serve as a model layer and capsules the professional application logic.
• Persistence Entities model the data model and are used for all database access.
• Java Server Pages and various static files form the view and generate the HTML code displayed on the screen.

The following development tools are used:

• Netbeans: Integrated development environment for Java and other languages
• Maven: Build tool and management of dependencies
• Git: version management for working together on the source code
• Tomee: Application server for the local testing of the application
• Derby: SQL database implemented in Java for testing the application

Configuration of user authentication

In the classes justdoit.common.jpa.user and justdoit.common.ejb.userbean, the user administration was realized. The application manages a separate table in the database in which the users, passwords and assigned user groups are saved.

However, authentication and authorization are carried out by the application server, which must be configured accordingly. This means that the application server must know in which tables the users are saved. This is based on the settings in the file /Web Pages/WEB-INF/web.xml .

There are the application -specific settings that require actions which permits require. In the end, the following line is

    <realm-name>justdoit</realm-name>

assigned the realm. Realm is only a nice term for any database with users, your passwords and permissions.

In the Tomee, this happens through the following lines in the conf/server.xml configuration file: The definition of the realm is done by the following lines in the file /Web Pages/META-INF/context.xml :

    <Realm
            className      = "org.apache.catalina.realm.DataSourceRealm"

            dataSourceName = "Default-Database-Unmanaged"
            userTable      = "justdoit.justdoit_user"
            userNameCol    = "username"
            userCredCol    = "password_hash"

            userRoleTable  = "justdoit.user_group"
            roleNameCol    = "groupname"
        >
            <CredentialHandler
                className = "org.apache.catalina.realm.MessageDigestCredentialHandler"
                algorithm = "SHA-256"
            />
    </Realm>

The database connection mentioned under dataSourceName must be defined as follows in the File conf/tomee.xml :

    <Resource id="Derby-Sample-Managed" type="javax.sql.DataSource">
        JdbcDriver = org.apache.derby.jdbc.ClientDriver
        JdbcUrl    = jdbc:derby://localhost:1527/sample
        UserName   = app
        Password   = app
        JtaManaged = true
    </Resource>

    <Resource id="Derby-Sample-Unmanaged" type="javax.sql.DataSource">
        JdbcDriver = org.apache.derby.jdbc.ClientDriver
        JdbcUrl    = jdbc:derby://localhost:1527/sample
        UserName   = app
        Password   = app
        JtaManaged = false
    </Resource>

The example is based on the derby example database, which is part of Netbeans.

Notes on email shipping

The email shipping is implemented with the Javamail API. Part of the required settings is saved in a JSON file: src/main/resources/mailConfig.json

 {
    "from": "",
    "host": "",
    "port": "",
    "username": "",
    "password": ""
}

• from : Address that should be displayed as the sender address.
• host : Address of the postal exit gender (SMTP server)
• port : Port of the output server (SMTP server)
• username : Username of the account at the mail provider
• password : Password of the account at the mail provider

copyright

This project is licensed under Creative Commons name 4.0 International

© 2018 - 2019 André Göller, Tim Schneider, Ansgar Lichter