Java通配符导入失败，非通配符导入正常问题咨询

Hey there, let's break down why you're hitting that "bad source file" error and fix it step by step! The core problem here is a mismatch between your package declarations and directory structure, plus missing compile-time flags that help the compiler find your classes.

What's Going Wrong? #

1. Incorrect Source File Placement: Your Foo.java and Bar.java declare package hoge.fuga;, but they're sitting directly in the src/ directory. Java requires source files for a package hoge.fuga to live in a src/hoge/fuga/ subdirectory—this is how the compiler maps package names to file system paths.
2. Missing Compilation Context: You're not telling the compiler where to output compiled class files or where to look for existing classes, so it can't resolve the hoge.fuga package properly.

Step-by-Step Fix #

1. Fix Your Directory Structure

Move Foo.java and Bar.java into the correct subdirectory under src/. Your final structure should look like this:

+ src/
  - Senario.java  // Rename to match your class name (capital S—Java is case-sensitive!)
  + hoge/
    + fuga/
      - Foo.java   // package hoge.fuga;
      - Bar.java   // package hoge.fuga;
+ hoge/
  + fuga/
    - Foo.class
    - Bar.class

Pro tip: Windows might ignore filename case, but Java doesn't—keeping filenames matching class names avoids cross-platform headaches later.

2. Compile the hoge.fuga Package Classes

Open Command Prompt, navigate to the src/ directory, and run this command:

javac -d .. hoge/fuga/Foo.java hoge/fuga/Bar.java

• The -d .. flag tells the compiler to output compiled .class files to the parent directory (matching your existing hoge/fuga/ structure outside src/).

3. Compile Senario.java

Still in the src/ directory, run this command to compile your main class:

javac -cp .. Senario.java

• The -cp .. flag adds the parent directory to the classpath, so the compiler can find the hoge.fuga package classes you just compiled.

Test It Out #

After compiling, you can run your class with:

java -cp .. Senario

This should resolve the imports and run without errors!

内容的提问来源于stack exchange，提问作者mogami74