Juno

Juno is a utility library designed to simplify common tasks in Java and Android development. It provides a set of helpful methods for data conversion, string manipulation, collections handling, file I/O, and more.

Installation

To include Juno in your project using Gradle, add the following dependency:

dependencies {
  implementation 'com.github.jesusbmx:juno:1.0.3'
}

Alternatively, you can download the JAR file directly from JitPack:

Download juno.jar

Documentation

Convert

int i = Convert.toInt("1", -1); // 1
float f = Convert.toFloat("1.1"); // 1.1f
double d = Convert.toDouble("2.2"); // 2.2d
double l = Convert.toLong("1000"); // 1000L
String str = Convert.toString(f, ""); // "1.1"
boolean bool = Convert.toBool("true"); // true

Base64

Encoding and decoding in Base64:

String encodeBase64 = Convert.toBase64("Hello world");
System.out.println(encodeBase64); // SGVsbG8gd29ybGQ=

String decodeBase64 = Convert.fromBase64(encodeBase64);
System.out.println(decodeBase64); // Hello world

Strings

Validate if a string is empty:

String txt = null;
if (Strings.isEmpty(txt)) {
  System.out.println("txt is empty");
}

Assign default value if null:

txt = Validate.ifNull(txt, "Hello world");
System.out.printf("txt = '%s'\n", txt); // txt = 'hello world'

Abbreviate a string:

txt = Strings.abbreviate(txt, 7);
System.out.printf("txt = '%s'\n", txt); // txt = 'hello...'

Trim and capitalize a string:

String name = "jesus   ";
name = Strings.trim(name);
name = Strings.capitalize(name);
System.out.printf("name = '%s'\n", name);  // name = 'John'

Get a substring between two characters:

System.out.println(Strings.subStr("[Hello world]", "[", "]")); // Hello world

Numbers

Validate if a value is numeric and convert it:

String number = "-892768237.50";
if (Numbers.isNumber(number)) {
  System.out.printf("'%f' is number\n", Convert.toDouble(number)); // '-892768237.500000' is number
} else {
  System.out.printf("'%s' not is number\n", number);
}

Convert numeric strings to integers and floats:

String str = "10.80";

int i = Convert.toInt(str);
System.out.printf("i = '%d'\n", i); // i = '10'

float f = Convert.toFloat(str);
System.out.printf("f = '%f'\n", f); // f = '10.800000'

Round a number to a specified number of decimal places:

double round = Numbers.roundAvoid(948.856099955012, 2);
System.out.println(round); // 948.86

Lists, Arrays

List<String> strList = Lists.listOf("1", "2", "3", "7", "9");
List<Integer> intList = Lists.map(strList, (String it) -> Convert.toInt(it) );

if (Lists.hasIndex(strList, 2)) {
    System.out.printf("list[2] = '%s'\n", strList.get(2)); // list[2] = '3'
}

if (Lists.isEmpty(strList)) {
    System.out.println("list is empty");
}

System.out.println(Lists.getValueOrDefault(strList, 50, "defaultVal")); // defaultVal

System.out.println(Strings.join(strList)); // 1,2,3,7,9
System.out.println(Strings.join(strList, (element) -> "\"" + element.toString() + "\"" )); // "1","2","3","7","9"

boolean some = Lists.some(strList, (element) -> element.equals("7") );
System.out.println(some); // true

boolean every = Lists.every(intList, (element) -> element % 2 == 0 );
System.out.println(every); // false

String find = Lists.find(strList, (element) -> element.equals("9") );
System.out.println(find); // 9

List<Integer> filter = Lists.filter(intList, (element) -> element > 5 );
System.out.println(Strings.join(filter, ",")); // 7,9

List<String> fill = Lists.fill(strList, "z");
System.out.println(Strings.join(fill, ",")); // z,z,z,z,z

Maps

Create and manipulate maps:

final Map<String, Integer> map = Maps.of(
    "one", 1, 
    "two", 2, 
    "three", 3
);

System.out.println(map); // {one=1, two=2, three=3}
System.out.println(Maps.getValueOrDefault(map, "one", -1)); // 1

Map<Integer, String> convertedMap2 = Maps.convert(
    map,
    entry -> entry.getValue(),
    entry -> entry.getKey() + "-" + entry.getValue()
);
System.out.println(convertedMap2); // {1=one-1, 2=two-2, 3=three-3}

Get values from a map with default values:

int intValue = Maps.getInt(map, "one", 0);
System.out.println(intValue); // 1

float floatValue = Maps.getFloat(map, "nonexistentKey", 0.0f);
System.out.println(floatValue); // 0.0

double doubleValue = Maps.getDouble(map, "two", 2.5);
System.out.println(doubleValue); // 2.0

boolean boolValue = Maps.getBoolean(map, "nonexistentKey", false);
System.out.println(boolValue); // false

Date

String sDate = "2023-04-30 19:10:02";
        
Calendar date = Dates.parseCalendar(sDate, "yyyy-MM-dd");
System.out.println(Dates.dateTimeFormat(date)); // 2023-04-30 00:00:00

Date dateTime = Dates.parseDate(sDate, "yyyy-MM-dd HH:mm:ss");
System.out.println(Dates.dateTimeFormat(dateTime)); // 2023-04-30 19:10:02


System.out.println(Dates.dateFormat(new Date())); // 2023-05-03
System.out.println(Dates.dateTimeFormat(new Date())); // 2023-05-03 12:31:47
System.out.println(Dates.format("yyyy-MM-dd HH:mm:ss", new Date())); // 2023-05-03 12:31:47


Calendar cDate = Dates.calendarWithoutTime(); // get date without time
System.out.println(Dates.dateTimeFormat(cDate)); // 2023-05-03 00:00:00

Calendar cDateTime = Dates.calendarWithTime(); // get date and time
System.out.println(Dates.dateTimeFormat(cDateTime)); // 2023-05-03 12:31:47

// ISO_8601_24H_FULL_FORMAT
Date date_iso_8601 = Dates.parseDate("2023-06-20T19:18:11.000Z", 
        "yyyy-MM-dd'T'HH:mm:ss.SSSXXX");

System.out.println(Dates.dateTimeFormat(date_iso_8601)); // 2023-06-20 13:18:11

Async Await

Async<String> read(final File file) {
  return new AsyncCallable<>(() -> {
    //throw new Exception("error");
    return Files.readString(file);
  });
}

Run tasks asynchronously

File file = new File("/home/user/a.txt");

read(file).execute((String result) -> {
  System.out.println(result);

}, (Exception error) -> {
  System.err.println(error);

});

Run tasks synchronously

try {
  File file = new File("/home/user/a.txt");

  String result = read(file).await();
  System.out.println(result);

} catch(Exception error) {
  System.err.println(error);
}

Async Sender

Async<String> read(final File file) {
  return new AsyncSender<>((sender) -> {
    //sender.reject(throw new Exception("error"));
    String result = Files.readString(file);
    sender.resolve(result);
  });
}

Abstract Async

Async<String> read(final File file) {
  return new AbstractAsync<String>() {
    @Override
    public String call() throws Exception {
      //throw new Exception("error");
      return Files.readString(file);
    }
 };
}

EventManager

EventManager receiver = EventManager.get("MyHandler");
receiver.on("log", (EventMessage<String> evt) -> {
    System.out.println(evt.getValue());
});

EventManager sender = EventManager.get("MyHandler");
sender.send("log", "Hola mundo");

EventManager receiver = EventManager.get("MyHandler");
receiver.once("status", (EventMessage<Integer> evt) -> {
    System.out.println(evt.getValue());
});

EventManager sender = EventManager.get("MyHandler");
sender.send("status", 200);

Paths

String basePath = "/home";

System.out.println(Paths.join('/', Arrays.of(
    basePath, "User/Desktop", "file.txt"
))); // /home/User/Desktop/file.txt

basePath = "/home/User/Documents/";

System.out.println(Paths.join('/', Arrays.of(
    basePath, "file.txt"
))); // /home/User/Documents/file.txt

basePath = "/home/User";

System.out.println(Paths.join('/', Arrays.of(
    basePath, "Downloads", "file.txt"
))); // /home/User/Downloads/file.txt

System.out.println(Paths.join('/', Arrays.of(
    "/home", "User2", "Downloads", "file.txt"
))); // /home/User2/Downloads/file.txt

System.out.println(Paths.join('/', Arrays.of(
    "/home", "User2", "Downloads"
))); // /home/User2/Downloads

IO

String path = "/etc/hola.txt";
File f = new File(path);

Files.write(f, "Hola mundo\n", /*append*/true, "UTF-8");

String str = Files.readString(f);
System.out.println(str);

System.out.printf("parent: %s\n", Files.getParent(path));
System.out.printf("name: %s\n", Files.getName(path));
System.out.printf("extension: %s\n", Files.getExtension(path));
System.out.printf("base name: %s\n", Files.getBaseName(path));

> Hola mundo
>
> parent: /etc/
> name: hola.txt
> extension: txt
> base name: hola

Read bytes.

byte[] bytes = Files.readByteArray(new File("/etc/hola.txt"));

Copy

Files.copy("/etc/hola.txt", "/etc/hola-copy.txt");

FileInputStream in = null;
FileOutputStream out = null;
try {
  in = new FileInputStream("/etc/hola.txt");
  out = new FileOutputStream("/etc/hola-copy.txt");
  Files.copy(in, out);

} finally {
  Files.closeQuietly(in);
  Files.closeQuietly(out);
}

Validate

String a = null;
String b = "b";
System.out.println(Validate.eq(a, b));
System.out.println(Validate.isNull(null));
System.out.println(Validate.isNotNull(null));

> false
> true
> false

License

Copyright 2018 juno, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.