alex-eyk / properties-provider

Library for loading .properties files

properties-provider

The library can help you load properties files and work with files from a directory with a .jar file.

Loading .properties files

1. Create class

First, you need to create a class with the same fields that the .properties file contains. Example:

    @PropertiesPath("jarpath:/config.properties")
    public class Config {
        
        @Property(name = "server.threads", defaultValue = "4")
        private int threads;
        
        public int getThreads() {
            return threads;
        }
        
    }

In this case, the .properties file is located in the same folder as the .jar file and its name – config.properties. If the file is located in the folder with application resources, the path should be written as follows: res:/config.properties. The file from the example contains one field with the server.threads key, which has an integer value. If such a file does not exist, it will be created automatically using default values.

2. Create instance of class

To create an instance of the previously created class, you should use the method createInstance of the PropertiesProvider object, passing it as an argument the class whose instance you want to create.

    final PropertiesProvider propertiesProvider = new PropertiesProvider();
    final Config config = propertiesProvider.createInstance(Config.class);

Getting files from a directory with a .jar file

To get files from a directory with a .jar file, use getFileFromJarDirectoryPath(String filename, Class<?> clazz) static function of the JarUtils class.

    public class SomeClass {
    
        private void someFunction() {
            final File configFile = JarUtils.getFileFromJarDirectoryPath("config.properties", getClass());
            
        }
    
        private static void someStaticFunction() {
            final File configFile = JarUtils.getFileFromJarDirectoryPath("config.properties", SomeClass.class);
            
        }
    }

Jar file path

You can use getJarLocation(Class<?> clazz) static function of the JarUtils class to get the path directly to the .jar file. If the class is in the file system (file with the .class extension), then the path to the base directory will be returned, otherwise (if the class is in the Jar file) the path to the Jar file will be returned.

    public class SomeClass {
    
        private void someFunction() {
            final URL jarLocation = JarUtils.getJarLocation(getClass());
            
        }
    
        private static void someStaticFunction() {
            final URL jarLocation = JarUtils.getJarLocation(SomeClass.class);
            
        }
    }

Other possibilities

JarUtils class also contains File urlToFile(URL url) and File urlToFile(String url) functions. These functions are equivalent to the following code:

    final File file = new File(url)

However, the functions of the JarUtils class additionally handle the situation when the url begins with "jar: file:" by returning the path to the .jar file.

Install

1. Download latest release
2. Move the downloaded file to the libs folder of your project. If such folder does not exist, create it.
3. Add dependency to your build.gradle file

    dependencies {
        implementation files('libs/PropertiesProvider-1.0.2.jar')
    
    }

or add all dependency from libs folder

    dependencies {
        implementation fileTree(dir: 'libs', include: ['*.jar'])
        
    }