The selection cannot be launched eclipse java ошибка - ErrorsMaster.ru - большая энциклопедия ошибок и их решений

I have looked everywhere on the internet and tried everything the forums say to do and nothing works.
This error keeps coming up. I have tried running my java project (not for android) even the drop down run as button doesn’t work because it says «none applicable».

Jon Clements

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asked Sep 15, 2014 at 23:24

Eclipse needs to see a main method in one of your project’s source files in order to determine what kind of project it is so that it can offer the proper run options:

public static void main(String[] args)

Without that method signature (or with a malformed version of that method signature), the Run As menu item will not present any run options.

answered Sep 15, 2014 at 23:54

MarsAtomicMarsAtomic

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Check, you might have written this statement wrong.

public static void main(String Args[])

I have also just started java and was facing the same error and it was occuring as i didn’t put [] after args.
so check ur statment.

ncica

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answered Aug 31, 2015 at 17:17

Click on the drop down next to the Run button, After that choose Run Configuration, shows three option, for example i choose java application add class(Name of the class of your project) in that then Click on the ok button …Run your application

Neeraj

answered Jun 23, 2015 at 12:32

When you create a new class file, try to mark the check box near

public static void main(String[] args) {

this will help you to fix the problem.

Leon Adler

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answered Jan 10, 2016 at 18:39

Emre TuranEmre Turan

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click on the project that you want to run on the left side in package explorer and then click the Run button.

answered Mar 4, 2016 at 2:17

Make sure the «m» in main() is lowercase this would also cause java not to see your main method, I’ve done that several times unfortunately.

answered Jul 29, 2015 at 19:02

FRANKFRANK

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It happens when sometimes we copy or import the project from somewhere. The source folder is a big thing to concern about.

One simple technique is, create a new project, inside the source folder, create a new class and paste the content over there.

It will work…

Hope it helps.

answered Nov 18, 2015 at 6:05

NishNish

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Have you checked if:

You created a class file under src folder in your JAVA project?(not file)
Did you name your class as the same name of your class file?

I am a newbie who try to run a helloworld example and just got the same error as yours, and these work for me.

answered Sep 2, 2018 at 19:21

Check if the filename is same as the classname used by your program.

eg.:

class Dfs{ psvm(String[] args){}}

filename should be Dfs.java

ncica

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answered Feb 17, 2018 at 14:30

XciAXciA

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Check there might be build error in problem message view.

answered Apr 2 at 7:11

yu yang Jianyu yang Jian

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Источник

The ‘Selection Cannot be Launched’ error in Eclipse is a common issue faced by Java developers. This comprehensive guide will walk you through the steps to resolve this error and get you back to coding in no time. Below, you’ll find a step-by-step solution for tackling this error, as well as an FAQ section to address any additional questions you may have.

Overview of the ‘Selection Cannot be Launched’ Error
Step-by-Step Solution
Step 1: Ensure the Correct Java Version is Installed
Step 2: Configure the Build Path
Step 3: Set the Main Class
Step 4: Configure the Run Configuration
FAQs
Related Links

Overview of the ‘Selection Cannot be Launched’ Error

The ‘Selection Cannot be Launched’ error in Eclipse typically occurs when the IDE is unable to find the main class or the Java Runtime Environment (JRE) to execute the Java application. This can be caused by various factors, such as incorrect Java version, misconfigured build path, or missing main class declaration.

Step-by-Step Solution

Follow these steps to resolve the ‘Selection Cannot be Launched’ error in Eclipse:

Step 1: Ensure the Correct Java Version is Installed

Open the Eclipse IDE and navigate to Window > Preferences.

In the Preferences window, expand the Java menu and click on Installed JREs.

Check if the installed JRE version matches the required version for your project. If not, click on Add to browse and add the correct JRE version.

Step 2: Configure the Build Path

Right-click on your project in the Project Explorer and select Properties.

In the Properties window, click on Java Build Path in the left pane.

Navigate to the Libraries tab and ensure that the correct JRE System Library is added. If not, click on Add Library to add the required JRE System Library.

Step 3: Set the Main Class

Ensure that your Java application has a main class with the proper main method signature:

public static void main(String[] args)

If your application is missing the main class or the main method, add them accordingly.

Step 4: Configure the Run Configuration

Click on the Run menu in the Eclipse IDE and select Run Configurations.

In the Run Configurations window, double-click on Java Application to create a new configuration.

Under the Main tab, click on Search next to the Main class field and select the main class of your Java application.

Click on Apply and then Run to execute your Java application without the ‘Selection Cannot be Launched’ error.

FAQs

Q1: How do I change the Java compiler version for my project in Eclipse?

Open the Properties window for your project by right-clicking on the project in the Project Explorer and selecting Properties. Click on Java Compiler in the left pane and check the Enable project-specific settings checkbox. Then, select the desired compiler version from the Compiler compliance level dropdown menu.

Q2: Can I have multiple Java versions installed on my system?

Yes, you can have multiple Java versions installed on your system. You can configure the Java version for each project in Eclipse by following the steps mentioned in Step 1: Ensure the Correct Java Version is Installed.

Q3: How do I update the JRE System Library in Eclipse?

To update the JRE System Library in Eclipse, follow the steps mentioned in Step 2: Configure the Build Path.

Q4: What should I do if the ‘Selection Cannot be Launched’ error persists even after following the steps in this guide?

Ensure that your project files and dependencies are up-to-date and error-free. You can also try creating a new Java project and importing the existing source files into the new project to resolve any hidden configuration issues.

Q5: How do I change the default JRE in Eclipse?

To change the default JRE in Eclipse, navigate to Window > Preferences > Java > Installed JREs, select the desired JRE from the list, and click on Apply and Close.

Eclipse Official Documentation
Java Build Path Configuration in Eclipse
Run Configurations in Eclipse

Источник

This tutorial demonstrates the Eclipse error The selection cannot be launched, and there are no recent launches in Java.

Eclipse `The selection cannot be launched` Error

When using Eclipse, an error The selection cannot be launched can occur. While we have a selection of classes and no class has the main method, this error will occur in Eclipse because Eclipse will only run the set of classes or an application when it finds the main class.

Eclipse needs to see the main method in one of the project files. Otherwise, it cannot run the application.

The main method should be properly defined as below.

public static void main(String[] args)

Without a proper definition of the main method, Eclipse will throw the The selection cannot be launched. Here is an example.

package delftstack;

public class Example {

    public static void main(String[] args[]) throws IOException {

       System.out.println("This is Delftstack.com");
    }
}

The code above will throw The selection cannot be launched because the main method is not properly defined. Here is the correct version of the code.

package delftstack;

public class Example {

    public static void main(String[] args) throws IOException {

       System.out.println("This is Delftstack.com");
    }
}

The [] is given to the String keyword in the main method statement. Now, this code will work properly.

See output:

Источник

I’ve been trying to do processing in eclipse by downloading processing and running it with eclipse. Every time I try to run anything it says «This selection cannot be launched and there are no recent launches» I’ve looked around for the same problem but none of them are for processing and mostly just for default java or android I’ve tried to make a run configuration but to no avail.
code

import processing.core.PApplet;
import processing.core.PImage;


public class processing extends PApplet
{
PImage background;
PImage paddleImage;

public void setup()
{
    size(800, 600);
    background = loadImage("background.png");
    paddleImage = loadImage("paddle.png");
}
public void draw()
{
    background(background);
}
public class Paddle
{
    PImage sprite;
    float xPos;
    float yPos;

    public Paddle(PImage paddleSprite, float xStart, float yStart)
    {
        sprite = paddleSprite;
        xPos = xStart;
        yPos = yStart;
    }
}
}

Pshemo

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asked Aug 5, 2016 at 19:47

If you’re running in eclipse, you need a main() method.

public static void main(String... args){
    String[] pArgs = {"MySketch"};
    MySketch mySketch = new MySketch();
    PApplet.runSketch(pArgs, mySketch);
}

This code assumes you have a class named MySketch that extends PApplet.

answered Aug 5, 2016 at 20:20

Kevin WorkmanKevin Workman

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Источник

Я только что начал программирование на Android, поэтому загрузил Eclipse и начал работу.

Создал мой первый проект после учебника отсюда: http://developer.android.com/training/basics/firstapp/creating-project.html#CommandLine

И когда я был на следующем уроке для запуска этого приложения отсюда: http://developer.android.com/training/basics/firstapp/running-app.html

Я сделал, как они сказали. Подключено мое устройство через USB, включена также отладка USB, но когда я нажал кнопку «Запуск на eclipse», вы получили указанную выше ошибку.

Что я сделал неправильно?

Ответ 1

Eclipse не может решить, что вы хотите запустить, и поскольку вы ничего не запускали раньше, он не может попробовать повторить запуск этого.

Вместо того, чтобы щелкнуть зеленую кнопку «запустить», щелкните раскрывающийся список рядом с ним и выберите «Запустить конфигурации». На вкладке Android убедитесь, что он установлен в вашем проекте. На вкладке «Цель» установите галочку и параметры, соответствующие целевому устройству. Затем нажмите «Выполнить». Следите за вкладкой «Консоль» в Eclipse — это позволит вам узнать, что происходит. После того, как вы установили свой набор настроек запуска, вы можете просто нажать зеленую кнопку «запустить» в следующий раз.

Иногда получить все, чтобы поговорить с вашим устройством, может быть проблематичным для начала. Рассмотрите возможность использования AVD (т.е. Эмулятора) в качестве альтернативы, по крайней мере, для начала, если у вас есть проблемы. Вы можете легко создать его в меню Window → Android Virtual Device Manager в Eclipse.

Чтобы просмотреть ход выполнения вашего проекта, который был установлен и запущен на вашем устройстве, проверьте консоль.
Это панель внутри Eclipse с вкладками «Проблемы/Javadoc/Декларация/Консоль/LogCat» и т.д. Она может быть сведена к минимуму — проверьте лоток в правом нижнем углу. Или просто используйте Window/Show View/Console в меню, чтобы оно стало на первый план. Есть две консоли, Android и DDMS — есть выпадающий список, где вы можете переключаться.

Ответ 2

Выполните следующие действия, чтобы запустить приложение на подключенном устройстве.
1. Измените каталоги в корневой части вашего Android-проекта и выполните:
ant debug
2. Убедитесь, что каталог Android SDK platform-tools/ включен в переменную среды PATH, затем выполните: adb install bin/<*your app name*>-debug.apk
На вашем устройстве найдите <*your app name*> и откройте его.

Обратитесь Запуск приложения

Источник

Table of Contents

Overview of the ‘Selection Cannot be Launched’ Error

Step-by-Step Solution

Step 1: Ensure the Correct Java Version is Installed

Step 2: Configure the Build Path

Step 3: Set the Main Class

Step 4: Configure the Run Configuration

FAQs

Q1: How do I change the Java compiler version for my project in Eclipse?

Q2: Can I have multiple Java versions installed on my system?

Q3: How do I update the JRE System Library in Eclipse?

Q4: What should I do if the ‘Selection Cannot be Launched’ error persists even after following the steps in this guide?

Q5: How do I change the default JRE in Eclipse?

Eclipse The selection cannot be launched Error

Ответ 1

Ответ 2

Eclipse `The selection cannot be launched` Error