Why is importing from the default package in Java considered bad practice?

Importing Classes from the Default Package in Java

Importing classes from the default package in Java is generally not recommended and is considered poor coding practice. Classes not declared within a specific package are automatically assigned to the default package, which lacks a unique identifier. This can lead to naming conflicts and difficulties in accessing these classes across different modules or applications.

Syntax to Import Default Package Classes

Despite the recommendation against importing default package classes, it is technically possible to do so in certain cases. However, there is no specific syntax defined in Java for importing such classes. Instead, you can use the following workaround:

<code class="java">import static <fully-qualified-class-name>;</code>

Example

Consider the following code:

MyClass.java (in the default package)

<code class="java">// No package declaration

public class MyClass {
    // ...
}</code>

OtherClass.java (in a specific package)

<code class="java">package com.example.myproject;

import static com.example.myproject.defaults.MyClass;

public class OtherClass {
    MyClass instance = new MyClass();
    // ...
}</code>

In this example, the OtherClass imports the MyClass from the default package using the static import syntax with the fully qualified class name. However, this approach should be avoided whenever possible and is only recommended for legacy code or in extremely rare scenarios.

Best Practice

The recommended practice in Java is to define all classes within specific packages to avoid name collisions and improve maintainability. The default package should only be used for very simple example programs or as an intermediary step during refactoring.

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