There are no problems with the lines of code, but what is bothering me would be this pile of information that appears in the Output window. I would like to see only the result of the code, written as I marked it in red:
You are freely choosing to write to the Output window in NetBeans, where other NetBeans processes also write their output, so arguably what you want to achieve is not reasonable or prudent, and there is some output in that window which you probably cannot suppress anyway.
That said, a simple change which may help a lot is to suppress all Maven output except error messages by adding the --quiet setting:
Tools > Options > Java > and click the Maven tab
Select Execution from the Categories tab, and enter --quiet in the Global Execution Options field.
Click Apply and OK.
That should get rid of most of the Maven output in the Output window, but note that:
Other NetBeans processes may will still write to it.
That --quiet setting is global, and will apply to all Maven projects you run within NetBeans.
An alternative approach is to direct all Maven output to a file using --log-file {filename} in the Global Execution Options field. You can couple this with the --quiet setting. For example: --log-file d:\temp\mvn1.txt --quiet which will create a file named mvn1.txt which only contains your output.
Yet another possible approach is to direct your application's output to a file independently of Maven. See this answer for how to do that for simple PrintStream ouput.
Related
I am a java beginner, the first java IDE I downloaded was Visual Studio Code, it was very easy to use and everything is auto configured. But it kind overheats my laptop all the time, so I want to try IDEA, so far it's a very good experience, except when I open a java file and tried to run it in IDEA, it always pops out this run configuration window and I don't understand how to configure it. In visual Studio Code I can open any java file any time and run without any issues, but now I have to go through creating projects every time. Is there any solution for this?
From how the file icon looks:
your file is not recognized as the part of the sources of your project. Check the project settings to ensure that source directories are correctly set.
I'd also recommend you to look up and follow the conventions for the directory structure of java projects.
Once you've fixed the problem with sources, you'll see "run" icon next to your class, main method, or when you're right clicking the file.
Command-line
To run a single file, there is no need for an IDE.
In Java 11 and later, the java tool at the command-line can both compile and execute a single-file Java class. See JEP 330: Launch Single-File Source-Code Programs.
If your class named HelloWorld were in a file named HelloWorld.java, on a console type:
java HelloWorld.java
To be clear: The java command-line tool really only executes Java apps, while the javac command-line tool compiles Java source code. As a convenience, the java tool was enhanced to effectively call javac on your behalf for a single-file.
JShell
If you just want to run a few lines of Java, try JShell, the REPL tool bundled with Java 9 and later.
See:
Java Shell User’s Guide by Oracle
JEP 222: jshell: The Java Shell (Read-Eval-Print Loop)
Search to learn more and find tutorials.
BlueJ
Using an IDE such as IntelliJ, NetBeans, or Eclipse can be a daunting task for the new student of Java. Those IDEs are heavy-duty tools designed for professional programmers.
I recommend using an IDE designed for beginners. BlueJ comes to mind, designed specifically for educational purposes. BlueJ makes getting started with Java easier.
If you insist on using IntelliJ, read on.
If using IntelliJ, define a project
IntelliJ is not designed to work with single files. IntelliJ expects you to work within a project.
I strongly recommend learning the basics of Maven to create and drive your new project. By defining your project in Maven, the configuration is independent of any one IDE. You can move your project between major IDEs such as IntelliJ, NetBeans, and Eclipse.
Maven is also very useful for downloading needed libraries ("dependencies") that you may want to leverage in your work. And Maven is good at packaging your Java app as a JAR (or WAR or EAR).
In IntelliJ, choose "New Project". In the New Project window, click the Maven item on left. Check the Create from archetype box. Scroll the list to find item for org.apache.maven.archetypes:maven-archetype-quickstart. Under that, choose the "RELEASE" item. Click Next button.
In Name field, enter something like MyFirstProject. Click Next button.
On the Maven settings page, just click Finish.
Wait a moment for IntelliJ to download some stuff and configure your project. Eventually you should see a BUILD SUCCESS message in the Run pane.
You will also see a pom.xml file displayed. The POM contains your settings for Maven to run your project, in XML format.
Change the <maven.compiler.source> and <maven.compiler.target> elements to the version of Java you are using. The current version is Java 17.
After editing the pom.xml, look for a little floating windoid with a tiny Maven icon. Click the icon to have Maven process your changed POM. Wait a moment.
In the Project pane, navigate to the App file. There you see code to print “Hello World!”. Let's run that code now. Click the green triangle button on the left, in the gutter, next to the main method line. A pop-up menu appears offering a Run item. Choose that item to run the app immediately.
Down in the Run pane, you should see the results, the Hello World! text.
At this point you can add your single file to the org.example package seen in the Project pane.
By the way, you can change that package name by context-clicking and choosing Refactor > Rename….
Later, learn to use the Run/debug configurations feature of IntelliJ.
Know that you need not create a new project for each time you want to do a little experiment. Create one project for such experiments. Keep adding new .java class files for each experiment. Delete old class files you no longer need.
Eventually, I suggest updating the versions of various items in your POM. The QuickStart archetype is not configured for the latest versions (for reasons I cannot fathom).
And when you learn about unit testing, replace JUnit 4 in the POM with JUnit Jupiter (Aggregator) to use JUnit 5. One of the benefits of using Maven is that you can easily switch out dependencies such as going from JUnit 4 to JUnit 5.
The IDE needs to know what's called the entry point of the program, i.e. where to start running your code. That's what the "Edit Configuration" window is wanting you to do.
If your file "Lab3.java" is in a package, make sure to fully specify that in the field you have in red. Otherwise without knowing how your project is structured (as the other answer alludes to), it's difficult to pinpoint what we're missing here.
When you create your IntelliJ project, add a directory /src right at the root of your project. Right click on that folder and tell IntelliJ that you wish to mark it as a source root. The directory should turn blue in color.
Put your packages under /src. IntelliJ will know that those are Java files.
When you want to run a class with a main method, choose Run->Edit Configurations. Tell IntelliJ that you want to add an Application. It should prompt you with the classes that have main methods in them. You'll have no trouble running them.
Use Maven or Graddle. Make sure the project is configured with the build tool enabled and integrated, it will do basic things automatically. If you are not sure, please create a new project and add your files in. Steps:
Open the IDE
New Project
Choose from the left side bar "Maven" or "Graddle"
Give it a name and the location in your machine.
Click Finish
Now you have the project ready. You need the appropriate method to run in java. A main class. In IntelliJ you can just type "main" and the auto-complete will add it for you, make sure you inside the curly brackets of the class {}. More info about the main class. You seem to have this nailed down.
Lastly make sure you have a JDK installed in the IDE. I am pretty sure this is your issue here, make sure to use one of the option IntelliJ provides. A full guide from the developers is here and should satisfy your needs. I would suggest OpenJDK for a beginner, because that served me well at the beginning, at the end of the day its your choice.
I start coding java with VScode recently. I have a simple problem. The problem is that I do not want the output to be like that. In other words, I do not want the program to run in the terminal as shown below. I just want the statements to be printed alone. Here, I just want (Hello world) only to be printed with nothing else. I googled how to run a java program and I found that the output must appear in either OUTPUT or DEBUG CONSOLE.
Can anyone please help me?. NOTE: I installed java 14 as well as all needed extensions in VScode for java.
If your code needn't input data, you can add this in the launch.json:
"console": "internalConsole"
The default value is:
"console": "integratedTerminal"
I do not suggest install the 'Code-Runner' extension, because it will compile the java file under the same folder of the java file, and mix them up.
And I recommended you to get used to the outputs, the outputs can provide useful information, let you know what's exactly the vscode does. If you run into some problems, you will need this information to help you to solve the problem.
In this case, you can just press Command F5 (Mac) or other keybindings (https://code.visualstudio.com/docs/getstarted/keybindings). This runs the program in your IDE. Otherwise, you can create a launch.json file to configure your debugging.
What you want to do is follow the instruction in Run and Debug Java in VS Code to setup a launch.json file. This defines how your code is launched and where the output from that debug session goes. You can customize the Debug output that appears by adding and configuring the User Settings for the Microsoft Java Debugger
Here are some things which you can do:
If you have installed all necessary extension packs, then the editor would display an option to Run & Debug the class on the code itself. (rare cases but it appeared while working in Linux)
Else type javac <name.java> in the terminal(output will be displayed in Terminal tab)
Or install the code runner extension which is available in VS Code Marketplace (that would display results in output tab easily)
I'm interested in being able to automatically clear the terminal every time I run my code (Java program with a main method that may or may not have packages inside the file). Code Runner only runs single class Java files and doesn't work with Java files that have packages so I'm not interested in that.
At the momement I'm running all my Java files by clicking on the "Run and Debug" button in VS Code. I'm aware that I can manually clear the console using Command + K (Mac) but doing this for every run feels repetitive so I'm looking for a way to do this automatically. Every time I click that run and debug button I'd like for it to clear the console before running an code. Is there also anyway to show a run button that maps to VS Code's "Run and Debug Button (Similar to the way Code Runner does it by displaying a run/triangle icon (left a screenshot below). Currently I have to make two clicks in order to click "Run and Debug".
I'm only looking for a solution that doesn't involve changing any Java files so something that involves changing settings/using an extension/related on VS code. I'm not looking to modify any Java file. Code Runner has the functionality I desire (clear terminal automatically) but doesn't work with all types of Java files so it again can't be used.
You could just put this line in your java file to clear the terminal.
For Windows:
Runtime.getRuntime().exec("cls");
For Linux:
Runtime.getRuntime().exec("clear");
If you can modify your output you can print an ANSI clear screen escape sequence before printing your first line of output.
System.out.println("\033[2J\033[1;1H");
Note, this will only work with VTE based terminals like Terminal.app, iTerm, almost all linux terminal emulators, Windows Powershell etc.
This problem is really becoming frustrating for me. I have this plugin which has a command, which works perfectly during runtime. When I click on the command during runtime, it does what it is expected to do (create a .cfg file from a .c file). After installation, I am encountering two issues:
The handler does not fire after I click on the command.
Nothing is printed on the console. I have another plugin whose handlers do what is expected of them after installation, but they fail to print any output to the console.
Where am I going wrong? Could someone please help?
Thank you.
Note: When I click on the command, the control actually goes into the handler class. It is just that it does nothing.
The Eclipse console shows the output of programs you are testing, it does not show the output of any plugins installed in Eclipse.
The output of things like System.out.print are discarded unless Eclipse is started with the -consoleLog option (and even then the output is not put in the console).
A plugin can use the various console APIs to create a console for output or to access an existing console.
I'm working with a Java program that has multiple components (with Eclipse & Ant at the moment).
Is there some way to start multiple programs with one launch configuration? I have an Ant target that does the job (launches multiple programs) but there are things I would like to do:
I would like to debug the programs with Eclipse, hence the need for Eclipse launch.
I would like to see the outputs for the programs at separate consoles.
Also other ways to launch multiple Java programs "with one click" with separate consoles and/or debugging would be ok.
['multiple launch part':]
If you have an ant launch configuration which does what you want, you can always transform it into a java launcher calling ant.
Main Class: org.apache.tools.ant.Main
-Dant.home=${resource_loc:/myPath/apache_ant}
-f ${resource_loc:/myProject/config/myFile-ant.xml}
You can then launch this ant session as a regular java application, with all eclipse debugging facilities at your disposal.
Add to your classpath in the User Entries section (before your project and default path):
ant.jar
ant-launcher.jar
[Multiple console part]
May be a possible solution would be to make sure your ant launcher actually launches the different application in their own JVM process (one javaw.exe for each application)
That way, you could use the ability of the native eclipse console to switch between different process.
The Console view clearly separates output from each distinct "process" and keeps them in several "buffers". The Console has a built-in "switch" feature that will automatically switch the view to display the buffer of the last process that performed output, however you can easily switch the display to any "process buffer" you want to look at.
To switch the Console "buffer" display, just click on the black "Down arrow" next to the 4th toolbar button from the right in the Console View's title bar (the button
that resembles a computer screen):
this will show a pop-down menu listing the "names" of all active process buffers, preceded by an "order number".
The one currently displayed will have a check-mark before its "order number". You can switch the view to another display buffer simply by clicking on its name.
The question and selected answer here are both 6 years old.
Eclipse Launch Groups provides UI to run multiple launch configs. Launch Groups is apparently part of CDT but can be installed separately without CDT by installing "C/C++ Remote Launch" (org.eclipse.cdt.launch.remote).
There's actually a ticket opened at Eclipse site which requests this very same functionality. One of the contributors there proposed a plugin which allows grouping more launch configurations (possibly of different types) and start all of them with one mouse click.
Although the plugin functionality is limited, it does a great job. Source code is included so you can make changes as necessary. You will have to open it as a PDE project in your Eclipse and export it as a JAR, then place the JAR file in your Eclipse' plugins folder. A bit cumbersome but you do this only one time. After that restart your Eclipse and look for "Basic Workflow" in your launch configurations dialog.
Plugin source is available here: https://bugs.eclipse.org/bugs/show_bug.cgi?id=39900#attach_177951