Error: class X is public should be declared in a file named X.java

The name of the public class within a file has to be the same as the name of that file.

So if your file declares class WeatherArray, it needs to be named WeatherArray.java

This happens when you have 1 name for the Java class on hard disk and another name of Java class in the code!!

For example, I renamed my MainActivity class to MainnActivity only (!) in the code. I got this error immediately.

There is also a visual indicator in the Project tab of Android Studio - a class inside a class, like you have nested classed, but with an error indicator.

The solution is to simply rename class name in the Project tab (SHIFT + F6) to match the name in the Java code.

I had the same problem but solved it when I realized that I didn't compile it with the correct casing. You may have been doing

javac Weatherarray.java

when it should have been

javac WeatherArray.java

You named your file as Main.java. name your file as WeatherArray.java and compile.

Just experience this issue today. Thanks to viewBinding.

Problem was the autoGenerated binding. I had two xml files

• one_two.xml
• onetwo.xml

Solution # 1 : Just use

tools:viewBindingIgnore="true"

in any one file.

Solution # 2 :

Rename the xml file

your file is named Main.java where it should be

WeatherArray.java

Yes! When you face these type of problem then try to following points

• Check Your .java file name and class name.
• If Class name and public class name are not the same then RENAME class name.

I my case, I was using syncthing. It created a duplicate that I was not aware of and my compilation was failing.

To avoid this error you should follow the following steps:

1) You should make a new java class

2) Name that class

3) And a new java class is made

I encountered the same error once. It was really funny. I had created a backup of the .java file with different filename but the same class name. And kept on trying to build it till I checked all the files in my folder.

In my case (using IntelliJ) I copy and pasted and renamed the workspace, and I am still using the old path to compile the new project.

In this case this particular error will happen too, if you have the same error you can check if you have done the similar things.

The terminal is not case sensitive when writing "Javac [x].java", so make sure what you write in the terminal matches the filename and class name.

My class name and file name were both "MainClass", but I was compiling using "Mainclass". Notice I forgot to make the "c" capital.

From Ubuntu command line:

//WeatherArray.java
public class WeatherArray {
  public static void main(String[] args) {
    System.out.println("....Hello World");
}}

ls

WeatherArray.java

javac WeatherArray.java

ls

WeatherArray.java WeatherArray.class

java WeatherArray

....Hello World

Of course if you name your java file with different name than WeatherArray, you need to take out public and it would be:

// Sunny.java
class WeatherArray {
   public static void main(String[] args) {
      System.out.println("....Hello World"); }}
// javac Sunny.java; java WeatherArray

If you make WeatherArray class from public to default.

public class WeatherArray =====> class WeatherArray

then you do not get any error and you can easily compile your code by just writing

==> javac any_name_you_assign_to_file.java

Now a WeatherArray.class will generate.

To run your code you have to use class name

==> java WeatherArray

Compile WeatherArray.java instead of Main.java

This error comes if you have not saved your source code with the same name of your public class name.

If your class name is the same as the filename then check that it does not contain any zero width character

I accidentally copied a class name with invisible whitespace which caused this exception

Eclipse was able to build the file and Gradle was not

This can be very confusing

Check to make sure you don't have two identical -- or very nearly identical -- files in your res/layout folder.

This solution is based on my experience with Kotlin, but probably should also work for Java.

In my resource files I had 2 files : item_alert_edit.xml and item_alertedit.xml. The compiler converts these files to .java and for some reason removes the _, so effectively both files will have the same name. I solved it by renaming one of the files to be different and this solved the error for me. Clean build, etc did not work for me.

public class Main {
    public static void main(String[] args) {
        Employee employee = new Employee(1, "John Doe", "Software Engineer", 50000.0, "1234567890");

        employee.updateName("John Doe Jr.");
        employee.updatePosition("Senior Software Engineer");

        // Attempt to update salary without authorization
        employee.updateSalary(60000.0, "INVALID_CODE"); // Unauthorized access denied!

        // Update salary with authorization
        employee.updateSalary(60000.0, "AUTHORIZED");

        // Retrieve and display employee details
        System.out.println("Employee ID: " + employee.getEmployeeID());
        System.out.println("Name: " + employee.getName());
        System.out.println("Position: " + employee.getPosition());
        System.out.println("Salary: " + employee.getSalary());
        System.out.println("Bank Account Number: " + employee.getBankAccountNumber());
    }
}

java: class Main is public, should be declared in a file named Main.java.solve thsi error in the above code

The answer is quite simple. It lies in your admin rights. before compiling your java code you need to open the command prompt with run as administrator. then compile your code. no need to change anything in your code. the name of the class need to be the same as the name of the java file.. that's it!!

error example:

public class MaainActivity extends Activity {

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Get the view from activity_main.xml
    setContentView(R.layout.activity_main);

  }
}

correct example:just make sure that you written correct name of activity that is"main activity"

public class MainActivity extends Activity {


  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Get the view from activity_main.xml
    setContentView(R.layout.activity_main);

  }
}

when you named your file WeatherArray.java,maybe you have another file on hard disk ,so you can rename WeatherArray.java as ReWeatherArray.java, then rename ReWeatherArray.java as WeatherArray.java. it will be ok.