AssignmentToCatchBlockParameter - Intellij Community

Reports assignments to, catch block parameters.

Changing a catch block parameter is very confusing and should be discouraged.

The quick-fix adds a declaration of a new variable.

Example:

void processFile(String fileName) throws Exception {
    try {
      doProcessFile(fileName);
    } catch(Exception ex) {
      if (ex instanceof UncheckedIOException) {
        // Warning: catch block parameter reassigned
        ex = ((UncheckedIOException) ex).getCause();
      }
      throw ex;
    }
  }

After the quick-fix is applied:

void processFile(String fileName) throws Exception {
    try {
      doProcessFile(fileName);
    } catch(Exception ex) {
      Exception unwrapped = ex;
      if (unwrapped instanceof UncheckedIOException) {
        unwrapped = ((UncheckedIOException)
          unwrapped).getCause();
      }
      throw unwrapped;
    }
  }