Utility

A collection of helpful utility functions and classes.

By Tom Ansill

Contents

• Utility - Collection of commonly used functions.

  • bytesToHex(byte[]) - Converts a byte array to hexidecimal string.
  • hexToBytes(String) - Converts a hexidecimal string to byte array.
  • format(String,Object,Object...) - Formats string, replaces any '{}' with object's toString() representation.
  • f(String,Object,Object...) - Shorthand function for format(String,Object,Object...).
  • simpleToString(Object) - toString() implementation for the lazy. It will create a string with class name and its fields. Example: MyDogClass(name="fido", color="Brown", age=1). In toString() of your classes, you just put Utility.simpleToString(this).
  • sensibleToString(Object object) - Simply adds double quotation marks between a String if input Object is a string, otherwise, returns toString() of non-String object. This function help to solve my minor beef with String's toString() implementation where one can easily confuse with null or "null" when object automatically gets converted to String in like System.out.println("Hello " + nullableString).
  • generateString(long) - Generates a random sequence of string. The characters in the random string will be alphanumeric [a-zA-z0-9].
  • generateString(Random, long) - Generates a random sequence of string with provided random generator. The characters in the random string will be alphanumeric [a-zA-z0-9].

• ResourceUtility - Collection of functions related to reading resources within .jar files.

  • getAllFilesInResource(Class<?>,String,boolean) - Scans all resources inside .jar file that owns the input Class<?> and outputs a Set<String> of path of resources.
  • getResourceListing(Class<?>,String) - Returns a listing of specified path in the .jar that owns the input Class<?>. NOTE: This is not same as getResource(String) because directories are not a thing in .jar files. All of the files are flattened into a single big root directory. Meaning if you export a .jar file and attempt to find a directory in it with just getResource(String), it wouldn't work.
  • getResourceFileContent(Class<?>,String) - Reads entire file in .jar that owns the input Class<?> and output it as String.

• Version - Class to detect and interpret versions in Jars. Assuming the Jar file will have manifest file that has version on it. Class will attempt to find it and interpret it. First it looks at package's getImplementationVersion(), then getSpecificationVersion(), finally, as last-resort, it will look for verison.properties in the resources. If that fails, then it will just output X.Y.Z.

• ExCollectors - Extended Collectors utility class for more terminal Stream functions.

  • toMap() - Convenience function of Collectors.toMap(K,V) if you are already streaming Map.Entry<K,V>. Equivalent to Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue).
  • toConcurrentMap() - Same as toMap() but as ConcurrentMap.

• function/* - Package of lambda functions

  • RunnableWithException - Variant of Runnable that throws Exception.
  • ConsumerWithException - Variant of Consumer that throws Exception.
  • FunctionWithException - Variant of Function that throws Exception.
  • SupplierWithException - Variant of Supplier that throws Exception.
  • BiConsumerWithException - Variant of BiConsumer that throws Exception.
  • BiFunctionWithException - Variant of BiFunction that throws Exception.
  • TriConsumer - Extension of Consumer but with 3 parameters.
  • TriConsumerWithException - Variant of TriConsumer that throws Exception.
  • TriFunction - Extension of Function but with 3 parameters.
  • TriFunctionWithException - Variant of TriFunction that throws Exception.
  • QuadConsumer - Extension of Consumer but with 4 parameters.
  • QuadConsumerWithException - Variant of QuadConsumer that throws Exception.
  • QuadFunction - Extension of Function but with 4 parameters.
  • QuadFunctionWithException - Variant of QuadFunction that throws Exception.

Prerequisites

• Java 8 or better
• Java Validation Library

Download and Install

Package Repository

The library is availble for download on Sonatype public Maven repository (https://oss.sonatype.org/#nexus):The library is availble for download on Sonatype public Maven repository (https://oss.sonatype.org/#nexus):

Utility (Utility, ResourceUtility, ExCollectors, and functions/*)

<dependency>
  <groupId>com.ansill.utility</groupId>
  <artifactId>utility</artifactId>
  <version>0.1.1</version>
</dependency>

Version

<dependency>
  <groupId>com.ansill.utility</groupId>
  <artifactId>version</artifactId>
  <version>0.1.1</version>
</dependency>

Build and Install

Maven (or other similar build tools) is needed to build and install JavaUtility

$ git clone https://github.com/tomansill/javautility
$ cd javautility
$ mvn install