* This exception indicates that an external command or process execution encountered an error.
 */
public class CommandExecutionException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructor with error message.
     * @param message The error message describing the command execution failure.
     */
    public CommandExecutionException(final String message) {

 * that don't declare ServletException in their throws clause.
 */
public class ServletRuntimeException extends RuntimeException {

    /** Serial version UID for serialization compatibility. */
    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ServletRuntimeException wrapping the given ServletException.
     *
     * @param e The ServletException to wrap
     */

 * This exception is used for errors during theme installation, uninstallation, or configuration.
 */
public class ThemeException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ThemeException with the specified message and cause.
     *
     * @param message the exception message
     * @param cause the underlying cause of this exception

 * This exception is used for errors during thumbnail creation and processing.
 */
public class ThumbnailGenerationException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new ThumbnailGenerationException with the specified message and cause.
     *
     * @param message the exception message

      "path": {
        "type": "keyword"
      },
      "generator": {
        "type": "keyword"
      },
      "target": {
        "type": "keyword"
      },
      "createdTime": {
        "type": "long"
      },
      "createdBy": {
        "type": "keyword"
      }
    }

 * This exception wraps underlying search engine errors and provides
 * meaningful error messages for troubleshooting.
 */
public class SearchEngineClientException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /**
     * Constructs a new SearchEngineClientException with the specified message and cause.
     *
     * @param message the detail message explaining the exception

        }
    }

    @Test
    public void test_longMessageHandling() {
        // Test handling of long messages
        StringBuilder longMessage = new StringBuilder();
        for (int i = 0; i < 1000; i++) {
            longMessage.append("Long message part ").append(i).append(" ");
        }
        String message = longMessage.toString();

 * This exception indicates that the required container or a specific component within it cannot be accessed.
 */
public class ContainerNotAvailableException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /** The name of the component that is not available. */
    private String componentName;

    /**
     * Constructor with component name.

    }

    private void setupMockConfig(String fesenUrl, String username, String password, String certificateAuthorities) {
        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            private static final long serialVersionUID = 1L;

            @Override
            public String getFesenHttpSslCertificateAuthorities() {
                return certificateAuthorities;
            }

            @Override

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user-facing features, what will the API look like?
* What test cases should it have? What could go wrong?
* How will it roughly be implemented? We'll happily provide code pointers to save you time.

We may ask you to answer these questions directly in the GitHub issue or (for large changes) in a shared Google Doc.