Руководство по пакетам в Java

ru/topjava/startjava/lesson1/

ru.topjava.startjava.lesson1

package ru.topjava.startjava.lesson1;

> tree /F
src
 └──ru
    └──topjava
       └───startjava
           └──lesson1
                MyFirstApp.java

package ru.topjava.startjava.lesson1;

public class MyFirstApp {

    public static void main(String[] args) {
        System.out.println("Я познаю Java!");
        System.out.println("Я программист.");
    }
}

> where /R C:\ src.zip
C:\Program Files\BellSoft\LibericaJDK-20\lib\src.zip
C:\Program Files\JetBrains\IntelliJ IDEA 2022.3\lib\ant\src.zip

org.springframework.beans.factory

org.springframework.context

src/main/java/org/springframework/
src/main/kotlin/org/springframework
src/test/java/org/springframework/
src/test/kotlin/org/springframework/

ru.topjava.basejava.exception
ru.topjava.basejava.sql
ru.topjava.basejava.storage.serializer

package ru.topjava.example;

class SomeClass {
    void method() {
        ...
    }
}

hyphenated-name.example.org → org.example.hyphenated_name
example.int → int_.example
123name.example.com → com.example._123name

java.io
jakarta.enterprise.lang.model
org.hibernate.action.internal
com.apple.quicktime.v3

org.springframework.kafka.aot
org.hibernate.beanvalidation
gov.whitehouse.socks.mousefinder

import java.util.Scanner;

java.util.Scanner console = new java.util.Scanner(java.lang.System.in);

Scanner console = new Scanner(System.in);

import java.util.Arrays;
import org.springframework.beans.BeansException;
import ru.topjava.basejava.storage.ArrayStorage;

import static java.lang.Math.max;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static ru.topjava.basejava.storage.DataStreamSerializer;

import java.util.*;
import jakarta.annotation.*;
import org.springframework.beans.factory.config.*

package ru.topjava.startjava.lesson1;

import java.lang.*;
import ru.topjava.startjava.lesson1.*;

public class MyFirstApp {

    public static void main(String[] args) {
        System.out.println("Я познаю Java!");
        System.out.println("Я программист");
    }
}

> md out & ls -a
./  ../  .git/  .gitignore  out/  src/

javac [options] [source-files]

> javac -d out/ src/ru/topjava/startjava/lesson1/*.java

> javac -d out/ src/ru/topjava/startjava/lesson1/MyFirstApp.java

package ru.topjava.clinic.animal;

public class Dog {

    private String name;

    public Dog(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void bark() {
        System.out.println("Bark! Bark! Bark!");
    }
}

package ru.topjava.clinic.person;

import ru.topjava.clinic.animal.Dog;

public class Owner {

    private String name;
    private Dog dog;

    public Owner(String name, Dog dog) {
        this.name = name;
        this.dog = dog;
    }

    public String toString() {
        return name + " и " + dog.getName();
    }
}

package ru.topjava.clinic;

import ru.topjava.clinic.animal.Dog;
import ru.topjava.clinic.person.Owner;

public class Main {
    public static void main(String[] args) {
        Dog dog = new Dog("Spike");
        Owner owner = new Owner("John", dog);

        System.out.println("Меня и мою собаку зовут " + owner);
        System.out.println("Голос, " + dog.getName());
        dog.bark();
    }
}

> tree /F src
src
└───ru
    └───topjava
        └───clinic
            │   Main.java
            │
            ├───animal
            │       Dog.java
            │
            └───person
                    Owner.java

javac -d out/ src/ru/topjava/clinic/animal/Dog.java src/ru/topjava/clinic/person/Owner.java src/ru/topjava/clinic/Main.java

javac -d out/ -sourcepath src/ src/ru/topjava/clinic/Main.java

java [options] [mainclass]

> java -cp out/ ru.topjava.startjava.lesson1.MyFirstApp

Я познаю Java!
Я программист.

java -cp out/ ru.topjava.clinic.Main

Меня и мою собаку зовут John и Spike
Голос, Spike
Bark! Bark! Bark!

javac -d out/ -sourcepath src/ src/ru/topjava/clinic/Main.java
java -cp out/ ru.topjava.clinic.Main

java src\ru\topjava\clinic\Main.java

Меня и мою собаку зовут John и Spike
Голос, Spike
Bark! Bark! Bark!

> javac @argfile

-d ..\..\..\..\out
Dog.java
Person.java
Main.java

-d D:\Java\StartJava\out
Dog.java
Person.java
Main.java

> javac @options

> javac @options *.java

> javac '@options'

find ./src/ -type f -name "*.java" > sources

> cat sources
./src/ru/topjava/clinic/Dog.java
./src/ru/topjava/clinic/Main.java
./src/ru/topjava/clinic/Person.java

dir src\*.java /S /B > sources

javac @options @sources

> shopt globstar
globstar        off

> shopt -s globstar

> shopt -u globstar

> javac -d out/ src/**/*.java

> javac -d out/ -sourcepath src/ src/**/*.java

> find ./src/ -type f -name "*.java" -exec javac -d ./out/ '{}' +

> java @argfile

-cp ..\..\..\..\out
ru.topjava.clinic.Main

-cp D:\Java\StartJava\out
ru.topjava.clinic.Main

> java @optionsj

ru.topjava.abc
ru.topjava.def
ru.topjava.ghi

package ru.topjava.abc;

import ru.topjava.def.Message;
import ru.topjava.ghi.Message;

public class Main {

    public static void main(String[] args) {
        Message msg1 = new Message();
        msg1.print();

        Message msg2 = new Message();
        msg2.print();
    }
}

package ru.topjava.def;

public class Message {

    public void print() {
        System.out.println("def.Message");
    }
}

package ru.topjava.ghi;

public class Message {

    public void print() {
        System.out.println("ghi.Message");
    }
}

> javac -d out/ src/ru/topjava/**/*.java

> javac -d out/ -sourcepath src/ru/topjava/ src/ru/topjava/abc/Main.java

src\ru\topjava\abc\Main.java:4: error: a type with the same simple name is already defined by the single-type-import of Message
import ru.topjava.ghi.Message;
^
src\ru\topjava\abc\Main.java:9: error: reference to Message is ambiguous
        Message msg1 = new Message();
        ^
  both class ru.topjava.def.Message in ru.topjava.def and class ru.topjava.ghi.Message in ru.topjava.ghi match
src\ru\topjava\abc\Main.java:9: error: reference to Message is ambiguous
        Message msg1 = new Message();
                           ^
  both class ru.topjava.def.Message in ru.topjava.def and class ru.topjava.ghi.Message in ru.topjava.ghi match
src\ru\topjava\abc\Main.java:12: error: reference to Message is ambiguous
        Message msg2 = new Message();
        ^
  both class ru.topjava.def.Message in ru.topjava.def and class ru.topjava.ghi.Message in ru.topjava.ghi match
src\ru\topjava\abc\Main.java:12: error: reference to Message is ambiguous
        Message msg2 = new Message();
                           ^
  both class ru.topjava.def.Message in ru.topjava.def and class ru.topjava.ghi.Message in ru.topjava.ghi match
5 errors

package ru.topjava.abc;

public class Main {

    public static void main(String[] args) {
        ru.topjava.def.Message msg1 = new ru.topjava.def.Message();
        msg1.print();

        ru.topjava.ghi.Message msg2 = new ru.topjava.ghi.Message();
        msg2.print();
    }
}

> javac -d out/ src/ru/topjava/**/*.java
> java -cp out/ ru.topjava.abc.Main
def.Message
ghi.Message