This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Shell 3.3.1! |
Command Catalog
The CommandCatalog
interface defines how command registrations exist in
a shell application. It is possible to dynamically register and de-register
commands, which gives flexibility for use cases where possible commands
come and go, depending on a shell’s state. Consider the following example:
CommandRegistration registration = CommandRegistration.builder().build();
catalog.register(registration);
Command Resolver
You can implement the CommandResolver
interface and define a bean to dynamically
resolve mappings from a command’s name to its CommandRegistration
instances. Consider
the following example:
static class CustomCommandResolver implements CommandResolver {
List<CommandRegistration> registrations = new ArrayList<>();
CustomCommandResolver() {
CommandRegistration resolved = CommandRegistration.builder()
.command("resolve command")
.build();
registrations.add(resolved);
}
@Override
public List<CommandRegistration> resolve() {
return registrations;
}
}
A current limitation of a CommandResolver is that it is used every time commands are resolved.
Thus, we advise not using it if a command resolution call takes a long time, as it would
make the shell feel sluggish.
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Command Catalog Customizer
You can use the CommandCatalogCustomizer
interface to customize a CommandCatalog
.
Its main use is to modify a catalog. Also, within spring-shell
auto-configuration, this
interface is used to register existing CommandRegistration
beans into a catalog.
Consider the following example:
static class CustomCommandCatalogCustomizer implements CommandCatalogCustomizer {
@Override
public void customize(CommandCatalog commandCatalog) {
CommandRegistration registration = CommandRegistration.builder()
.command("resolve command")
.build();
commandCatalog.register(registration);
}
}
You can create a CommandCatalogCustomizer
as a bean, and Spring Shell handles the rest.