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.
To include Juno in your project using Gradle, add the following dependency:
dependencies {
implementation 'com.github.jesusbmx:juno:1.0.6'
}
Alternatively, you can download the JAR file directly from JitPack:
Download juno.jar
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"); // trueEncoding 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 worldValidate 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 worldValidate 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); // 948.86List<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,zCreate 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); // falseString 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
/*Date date_iso_8601 = Dates.parseDate("2023-06-20T19:18:11.000Z",
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX");*/
Date date_iso_8601 = Dates.parseIso8601Compat("2023-06-20T19:18:11.000Z");
System.out.println(Dates.dateTimeFormat(date_iso_8601)); // 2023-06-20 13:18:11Defining a task
Task<String> read(final File file) {
return new AsyncTask<>(() -> {
//throw new Exception("error");
return Files.readString(file);
});
}Run tasks asynchronously
It runs in the background and reports the result via callbacks:
File file = new File("/home/user/a.txt");
read(file).async(
(String result) -> {
System.out.println(result);
},
(Exception error) -> {
System.err.println(error);
}
);Run tasks synchronously
It runs in a blocking manner and returns the result directly or throws an exception:
try {
File file = new File("/home/user/a.txt");
String result = read(file).sync();
System.out.println(result);
} catch(Exception error) {
System.err.println(error);
}AsyncSender allows you to implement a task by manually resolving or rejecting its result:
Task<String> read(final File file) {
return new AsyncSender<>((sender) -> {
//sender.reject(throw new Exception("error"));
String result = Files.readString(file);
sender.resolve(result);
});
}Task<String> read(final File file) {
return new AbstractTask<String>() {
@Override
public String call() throws Exception {
//throw new Exception("error");
return Files.readString(file);
}
};
}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);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/DownloadsString 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: holaRead 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);
}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
> falseCopyright 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.