In which situations should checked exception types be used?

Checked exceptions in Java should be used in situations where an error is expected and must be either handled or explicitly propagated further. This helps to make the developer think about possible errors and take appropriate measures.

Typical use cases:

• Input/output errors (e.g., FileNotFoundException)
• Errors when working with databases
• Errors related to network operations

Checked exceptions are suitable for situations where:

• The error is not fatal and can be recovered from
• Explicit notification of the calling code about a potential problem is required

Example:

public void readFile(String path) throws IOException {
    FileReader reader = new FileReader(path);
    // ...
}

Here, IOException is a checked exception, and the calling method must either handle it or declare it further.