Java

Java

1. Java

Java

java.util.ArrayList
java.util.LinkedList
java.util.HashMap Map
java.util.Vector
java.util.HashSet Set
java.util.Scanner
java.util.regex.Pattern
java.util.regex.Macher
IO/NIO java.io.File
java.nio.file.Files
java.io.InputStream
java.io.OutputStream
java.lang.Thread
java.util.concurrent.ExecutorService
java.time.LocalDate
java.time.LocalDateTime
java.time.ZonedDateTime
java.util.Date
java.text.SimpleDateFormat
java.util.Calendar
java.util.GregorianCalendar
java.time.Instant
java.time.ChronoUnit
java.time.Period
java.time.Duration
java.net.URL URL
java.net.Socket

2.

Java

JSON Jackson JSON / https://github.com/FasterXML/jackson
Gson Google JSON https://github.com/google/gson
JUnit Java https://junit.org/junit5/
Mockito Mock https://site.mockito.org/
Log4j https://logging.apache.org/log4j/
SLF4J https://www.slf4j.org/
Web Spring Framework https://spring.io/projects/spring-framework
Spring Boot https://spring.io/projects/spring-boot
Hibernate ORM https://hibernate.org/
MyBatis SQL https://mybatis.org/mybatis-3/
Maven https://maven.apache.org/
Gradle https://gradle.org/

3.

3.1

3.2

  • LTS ()

4.

4.1 Jackson JSON

import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonExample {
    public static void main(String[] args) {
        ObjectMapper mapper = new ObjectMapper();
        try {
            // JSON
            String json = mapper.writeValueAsString(new User("", 25));
            System.out.println(json);
           
            // JSON
            User user = mapper.readValue(json, User.class);
            System.out.println(user);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

4.2 JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class CalculatorTest {
    @Test
    void testAdd() {
        Calculator calc = new Calculator();
        assertEquals(5, calc.add(2, 3));
    }
}