props4j

Comfortable Properties for Java

Simple and useful properties tools with no dependencies.

Cases

Props with auto convert values

import base.props4j.impl.MapProps;

MapProps props = new MapProps();
props.putVal("key1", 1);
props.putVal("key2", "val2");
props.putVal("key3", true);

String strVal_1 = props.strVal("key1"); //"1"
long longVal_1 = props.longVal("key1"); //1L
Boolean boolVal_1 = props.boolVal("key1"); //false

Default values for empty keys or bad values

int defVal =  props.intVal("unknown-key", 42); //42

File props with updates check

import base.props4j.impl.FileProps;
import java.io.File;

File file = new File("test.properties");
writeToFile(file, "key1 = 1");

FileProps props = new FileProps(file);
int val = props.intVal("key1"); //1

//update file
writeToFile(file, "key1 = 2");

Thread.sleep(...);

int newVal = props.intVal("key1"); //2

MultiProps for many sources

import base.props4j.impl.FileProps;
import base.props4j.impl.MultiProps;

MultiProps props = new MultiProps();
props.addSource(new FileProps(file1));
props.addSource(new FileProps(file2));

Enum for keys!

import base.props4j.DefValKey;

public enum Keys implements DefValKey {
	
	planets_in_solar_system(8),
	is_frog_green(true),
	myName("Evgeny"),
	star_wars_episodes_count(999.999d),
	...
}


MapProps props = new MapProps();
int defVal = Keys.planets_in_solar_system.intFrom(props); //8
		
props.putVal(planets_in_solar_system, 9);
int updatedVal = Keys.planets_in_solar_system.intFrom(props); //9

Expressions ${...} in values

props.putVal("url", "127.0.0.1");
props.putVal("link1", "${url}/some1");
props.putVal("link2", "${url}/some2");

String link1 = props.strVal("link1"); // 127.0.0.1/some1
String link2 = props.strVal("link2"); // 127.0.0.1/some2

Code examples

• Example 1: Simple MapProps and basic get-put methods
• Example 2: FileProps for file properties
• Example 3: FileProps and file updated check
• Example 4: MultiProps for many props sources
• Example 5: Java Enums are best keys for props!
• Example 6: Expressions ${...} in values

Production ready

Props4j has been successfully used on Cheapchat.me and in open source live-chat-engine project.

Installation to your project

Java 8 is required (sources can easily be ported to Java 6 or 7 -- but I'm on Java 8 now :))

by Maven

via stackoverflow

<dependencies>
	<dependency>
		<groupId>com.github.edolganov</groupId>
		<artifactId>props4j</artifactId>
		<version>1.0</version>
	</dependency>
</dependencies>

<repositories>
	<repository>
		<id>jitpack.io</id>
		<url>https://jitpack.io</url>
	</repository>
</repositories>

by Release build

Download and add props4j-1.0.jar to your project's classpath