Java编译报错：'{' expected 问题原因咨询

Hey there! Let's break down exactly why you're running into this compilation error.

错误的核心原因 #

The error message Main.java:3: error: '{' expected might make you think you forgot a curly brace at first glance, but the real problem is in your class definition line:

public class Bister.java {

In Java, class names cannot include the .java file extension. That .java suffix is only for your actual file name (like Bister.java), not the name of the class inside the file. When the compiler sees Bister.java as a class name, it gets confused—dots in identifiers are reserved for package structures (e.g., com.myapp.Bister), not file extensions. This invalid class name breaks the compiler's ability to parse the code structure properly, leading it to throw a misleading "missing brace" error.

修正后的代码示例 #

If your file is named Bister.java, your class definition should remove the .java suffix entirely, like this:

public class Bister {
    // Your class logic goes here
    public static void main(String[] args) {
        // Example main method
        System.out.println("Fixed the error!");
    }
}

额外提醒 #

• For public classes, the file name must exactly match the class name (Java is case-sensitive!). So if your class is Bister, the file must be named Bister.java—not bister.java or BisterClass.java.

内容的提问来源于stack exchange，提问作者Powiux