Manifold : Properties

Many Java applications incorporate properties resource files (*.properties files) as a means of separating configurable text from code:

resources/abc/MyProperties.properties:

my.chocolate = Chocolate
my.chocolate.dark = Dark Chocolate
my.chocolate.milk = Milk Chocolate

Unfortunately access to these files requires boilerplate library code and the use of hard-coded strings:

Properties myProperties = new Properties();
myProperties.load(getClass().getResourceAsStream("/abc/MyProperties.properties"));

println(myProperties.getProperty("my.chocolate.dark"));

With the Properties type manifold we can access properties directly using simple, type-safe code:

println(abc.MyProperties.my.chocolate.dark);

Behind the scenes the properties type manifold creates a Java class for the properties file, which reflects its hierarchy of properties. As you develop your application, changes you make in the file are immediately available in your code with no user intervention in between -- no code gen files and no compiling between changes.

IDE Support

Manifold is fully supported in IntelliJ IDEA and Android Studio.

Install

Get the Manifold plugin directly from within the IDE via:

Settings ➜ Plugins ➜ Marketplace ➜ search: Manifold

Sample Project

Experiment with the Manifold Sample Project via:

File ➜ New ➜ Project from Version Control ➜ Git

Enter: https://github.com/manifold-systems/manifold-sample-project.git

Use the plugin to really boost your productivity. Use code completion to conveniently access properties. Make changes to your Properties files and use the changes immediately, no compilation! Find usages of any element in your Properties files. Perform rename refactors to quickly and safely make project-wide changes.

Setup

Building this project

The manifold-properties project is defined with Maven. To build it install Maven and run the following command.

mvn compile

Using this project

The manifold-properties dependency works with all build tooling, including Maven and Gradle. It also works with Java versions 8 - 21.

Binaries

If you are not using Maven or Gradle, you can download the latest binaries here.

Gradle

Note, if you are targeting Android, please see the Android docs.

Note, if you are using Kotlin, please see the Kotlin docs.

Here is a sample build.gradle script. Change targetCompatibility and sourceCompatibility to your desired Java version (8 - 21), the script takes care of the rest.

plugins {
    id 'java'
}

group 'systems.manifold'
version '1.0-SNAPSHOT'

targetCompatibility = 11
sourceCompatibility = 11

repositories {
    jcenter()
    maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' }
}

dependencies {
    testImplementation 'junit:junit:4.12'
    // Add manifold to -processorpath for javac
    annotationProcessor 'systems.manifold:manifold-properties:2024.1.34'
    compileOnly 'systems.manifold:manifold-rt:2024.1.34'
}

if (JavaVersion.current() != JavaVersion.VERSION_1_8 &&
    sourceSets.main.allJava.files.any {it.name == "module-info.java"}) {
    tasks.withType(JavaCompile) {
        // if you DO define a module-info.java file:
        options.compilerArgs += ['-Xplugin:Manifold', '--module-path', it.classpath.asPath]
    }
} else {
    tasks.withType(JavaCompile) {
        // If you DO NOT define a module-info.java file:
        options.compilerArgs += ['-Xplugin:Manifold']
    }
}

Use with accompanying settings.gradle file:

rootProject.name = 'MyProject'

If you are using module-info files, you must declare a static dependency on manifold.

module MyProject {
    requires static manifold;
}

Maven

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>my-properties-app</artifactId>
    <version>0.1-SNAPSHOT</version>

    <name>My Properties App</name>

    <properties>
        <!-- set latest manifold version here --> 
        <manifold.version>2024.1.34</manifold.version>
    </properties>

    <dependencies>
        <dependency>
            <!-- Necessary only during compile-time to resolve generated source-level annotations -->
            <groupId>systems.manifold</groupId>
            <artifactId>manifold-rt</artifactId>
            <version>${manifold.version}</version>
            <scope>provided</scope> <!-- dependency is only applied during compile-time for manifold-properties -->
        </dependency>
    </dependencies>

    <!--Add the -Xplugin:Manifold argument for the javac compiler-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                    <encoding>UTF-8</encoding>
                    <compilerArgs>
                        <!-- Configure manifold plugin-->
                        <arg>-Xplugin:Manifold</arg>
                    </compilerArgs>
                    <!-- Add the processor path for the plugin -->
                    <annotationProcessorPaths>
                        <path>
                            <groupId>systems.manifold</groupId>
                            <artifactId>manifold-properties</artifactId>
                            <version>${manifold.version}</version>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

If you are using module-info files, you must declare a static dependency on manifold.

module my.properties.app {
    requires static manifold;
}

Javadoc

manifold-properties:

License

Open source Manifold is free and licensed under the Apache 2.0 license.

Versioning

For the versions available, see the tags on this repository.

Author

• Scott McKinney