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#169 factory for instantiating declaratively registered subcommands
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Also reduced duplicate tracing for #83 reflective type converters.
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@remkop
remkop committed Dec 19, 2017
1 parent a87159e commit 24c1bc6
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Showing 2 changed files with 204 additions and 60 deletions.
161 changes: 102 additions & 59 deletions src/main/java/picocli/CommandLine.java
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Original file line number Diff line number Diff line change
Expand Up @@ -157,14 +157,25 @@ public class CommandLine {
private List<String> versionLines = new ArrayList<String>();

/**
* Constructs a new {@code CommandLine} interpreter with the specified annotated object.
* Constructs a new {@code CommandLine} interpreter with the specified annotated object and a default subcommand factory.
* When the {@link #parse(String...)} method is called, fields of the specified object that are annotated
* with {@code @Option} or {@code @Parameters} will be initialized based on command line arguments.
* @param command the object to initialize from the command line arguments
* @throws InitializationException if the specified command object does not have a {@link Command}, {@link Option} or {@link Parameters} annotation
*/
public CommandLine(Object command) {
interpreter = new Interpreter(command);
this(command, new DefaultFactory());
}
/**
* Constructs a new {@code CommandLine} interpreter with the specified annotated object and object factory.
* When the {@link #parse(String...)} method is called, fields of the specified object that are annotated
* with {@code @Option} or {@code @Parameters} will be initialized based on command line arguments.
* @param command the object to initialize from the command line arguments
* @param factory the factory used to create instances of {@linkplain Command#subcommands() subcommands} that are registered declaratively with annotation attributes
* @throws InitializationException if the specified command object does not have a {@link Command}, {@link Option} or {@link Parameters} annotation
*/
public CommandLine(Object command, IFactory factory) {
interpreter = new Interpreter(command, factory);
}

/** Registers a subcommand with the specified name. For example:
Expand Down Expand Up @@ -209,7 +220,7 @@ public CommandLine(Object command) {
* @see Command#subcommands()
*/
public CommandLine addSubcommand(String name, Object command) {
CommandLine subcommandLine = toCommandLine(command);
CommandLine subcommandLine = toCommandLine(command, interpreter.factory);
subcommandLine.parent = this;
interpreter.commands.put(name, subcommandLine);
subcommandLine.interpreter.initParentCommand(this.interpreter.command);
Expand Down Expand Up @@ -338,7 +349,7 @@ public List<String> getUnmatchedArguments() {
* @since 0.9.7
*/
public static <T> T populateCommand(T command, String... args) {
CommandLine cli = toCommandLine(command);
CommandLine cli = toCommandLine(command, new DefaultFactory());
cli.parse(args);
return command;
}
Expand Down Expand Up @@ -675,7 +686,7 @@ public List<Object> parseWithHandlers(IParseResultHandler handler, PrintStream o
* @throws IllegalArgumentException if the specified command object does not have a {@link Command}, {@link Option} or {@link Parameters} annotation
*/
public static void usage(Object command, PrintStream out) {
toCommandLine(command).usage(out);
toCommandLine(command, new DefaultFactory()).usage(out);
}

/**
Expand All @@ -687,7 +698,7 @@ public static void usage(Object command, PrintStream out) {
* @throws IllegalArgumentException if the specified command object does not have a {@link Command}, {@link Option} or {@link Parameters} annotation
*/
public static void usage(Object command, PrintStream out, Help.Ansi ansi) {
toCommandLine(command).usage(out, ansi);
toCommandLine(command, new DefaultFactory()).usage(out, ansi);
}

/**
Expand All @@ -699,7 +710,7 @@ public static void usage(Object command, PrintStream out, Help.Ansi ansi) {
* @throws IllegalArgumentException if the specified command object does not have a {@link Command}, {@link Option} or {@link Parameters} annotation
*/
public static void usage(Object command, PrintStream out, Help.ColorScheme colorScheme) {
toCommandLine(command).usage(out, colorScheme);
toCommandLine(command, new DefaultFactory()).usage(out, colorScheme);
}

/**
Expand Down Expand Up @@ -1068,7 +1079,7 @@ public CommandLine setExpandAtFiles(boolean expandAtFiles) {
private static boolean empty(Text txt) { return txt == null || txt.plain.toString().trim().length() == 0; }
private static String str(String[] arr, int i) { return (arr == null || arr.length == 0) ? "" : arr[i]; }
private static boolean isBoolean(Class<?> type) { return type == Boolean.class || type == Boolean.TYPE; }
private static CommandLine toCommandLine(Object obj) { return obj instanceof CommandLine ? (CommandLine) obj : new CommandLine(obj);}
private static CommandLine toCommandLine(Object obj, IFactory factory) { return obj instanceof CommandLine ? (CommandLine) obj : new CommandLine(obj, factory);}
private static boolean isMultiValue(Field field) { return isMultiValue(field.getType()); }
private static boolean isMultiValue(Class<?> cls) { return cls.isArray() || Collection.class.isAssignableFrom(cls) || Map.class.isAssignableFrom(cls); }
private static Class<?>[] getTypeAttribute(Field field) {
Expand Down Expand Up @@ -1706,6 +1717,31 @@ public interface ITypeConverter<K> {
*/
K convert(String value) throws Exception;
}

/**
* Subcommands registered declaratively on a parent command with the {@link Command#subcommands()} annotation
* are instantiated by a factory.
*/
public interface IFactory {
/**
* Creates and returns an instance of the specified class.
* @param cls the class to instantiate
* @return the new instance
* @throws Exception an exception detailing what went wrong when creating the instance
*/
Object create(Class<?> cls) throws Exception;
}
private static class DefaultFactory implements IFactory {
public Object create(Class<?> cls) throws Exception {
try {
return cls.newInstance();
} catch (Exception ex) {
Constructor<?> constructor = cls.getDeclaredConstructor();
constructor.setAccessible(true);
return constructor.newInstance();
}
}
}
/** Describes the number of parameters required and accepted by an option or a positional parameter.
* @since 0.9.7
*/
Expand Down Expand Up @@ -1941,11 +1977,63 @@ private class Interpreter {
private final List<Field> requiredFields = new ArrayList<Field>();
private final List<Field> positionalParametersFields = new ArrayList<Field>();
private final Object command;
private final IFactory factory;
private boolean isHelpRequested;
private String separator = Help.DEFAULT_SEPARATOR;
private int position;

Interpreter(Object command) {
Interpreter(Object command, IFactory factory) {
this.command = Assert.notNull(command, "command");
this.factory = Assert.notNull(factory, "factory");
Class<?> cls = command.getClass();
String declaredName = null;
String declaredSeparator = null;
boolean hasCommandAnnotation = false;
while (cls != null) {
init(cls, requiredFields, optionName2Field, singleCharOption2Field, positionalParametersFields);
if (cls.isAnnotationPresent(Command.class)) {
hasCommandAnnotation = true;
Command cmd = cls.getAnnotation(Command.class);
declaredSeparator = (declaredSeparator == null) ? cmd.separator() : declaredSeparator;
declaredName = (declaredName == null) ? cmd.name() : declaredName;
CommandLine.this.versionLines.addAll(Arrays.asList(cmd.version()));

for (Class<?> sub : cmd.subcommands()) {
Command subCommand = sub.getAnnotation(Command.class);
if (subCommand == null || Help.DEFAULT_COMMAND_NAME.equals(subCommand.name())) {
throw new InitializationException("Subcommand " + sub.getName() +
" is missing the mandatory @Command annotation with a 'name' attribute");
}
try {
CommandLine commandLine = toCommandLine(factory.create(sub), factory);
commandLine.parent = CommandLine.this;
commands.put(subCommand.name(), commandLine);
commandLine.interpreter.initParentCommand(command);
}
catch (InitializationException ex) { throw ex; }
catch (NoSuchMethodException ex) { throw new InitializationException("Cannot instantiate subcommand " +
sub.getName() + ": the class has no constructor", ex); }
catch (Exception ex) {
throw new InitializationException("Could not instantiate and add subcommand " +
sub.getName() + ": " + ex, ex);
}
}
}
cls = cls.getSuperclass();
}
separator = declaredSeparator != null ? declaredSeparator : separator;
CommandLine.this.commandName = declaredName != null ? declaredName : CommandLine.this.commandName;
Collections.sort(positionalParametersFields, new PositionalParametersSorter());
validatePositionalParameters(positionalParametersFields);

if (positionalParametersFields.isEmpty() && optionName2Field.isEmpty() && !hasCommandAnnotation) {
throw new InitializationException(command + " (" + command.getClass() +
") is not a command: it has no @Command, @Option or @Parameters annotations");
}
registerBuiltInConverters();
}

private void registerBuiltInConverters() {
converterRegistry.put(Object.class, new BuiltIn.StringConverter());
converterRegistry.put(String.class, new BuiltIn.StringConverter());
converterRegistry.put(StringBuilder.class, new BuiltIn.StringBuilderConverter());
Expand Down Expand Up @@ -2002,55 +2090,6 @@ private class Interpreter {
BuiltIn.registerIfAvailable(converterRegistry, tracer, "java.time.ZoneOffset", "of", String.class);

BuiltIn.registerIfAvailable(converterRegistry, tracer, "java.nio.file.Path", "java.nio.file.Paths", "get", String.class, String[].class);

this.command = Assert.notNull(command, "command");
Class<?> cls = command.getClass();
String declaredName = null;
String declaredSeparator = null;
boolean hasCommandAnnotation = false;
while (cls != null) {
init(cls, requiredFields, optionName2Field, singleCharOption2Field, positionalParametersFields);
if (cls.isAnnotationPresent(Command.class)) {
hasCommandAnnotation = true;
Command cmd = cls.getAnnotation(Command.class);
declaredSeparator = (declaredSeparator == null) ? cmd.separator() : declaredSeparator;
declaredName = (declaredName == null) ? cmd.name() : declaredName;
CommandLine.this.versionLines.addAll(Arrays.asList(cmd.version()));

for (Class<?> sub : cmd.subcommands()) {
Command subCommand = sub.getAnnotation(Command.class);
if (subCommand == null || Help.DEFAULT_COMMAND_NAME.equals(subCommand.name())) {
throw new InitializationException("Subcommand " + sub.getName() +
" is missing the mandatory @Command annotation with a 'name' attribute");
}
try {
Constructor<?> constructor = sub.getDeclaredConstructor();
constructor.setAccessible(true);
CommandLine commandLine = toCommandLine(constructor.newInstance());
commandLine.parent = CommandLine.this;
commands.put(subCommand.name(), commandLine);
commandLine.interpreter.initParentCommand(command);
}
catch (InitializationException ex) { throw ex; }
catch (NoSuchMethodException ex) { throw new InitializationException("Cannot instantiate subcommand " +
sub.getName() + ": the class has no constructor", ex); }
catch (Exception ex) {
throw new InitializationException("Could not instantiate and add subcommand " +
sub.getName() + ": " + ex, ex);
}
}
}
cls = cls.getSuperclass();
}
separator = declaredSeparator != null ? declaredSeparator : separator;
CommandLine.this.commandName = declaredName != null ? declaredName : CommandLine.this.commandName;
Collections.sort(positionalParametersFields, new PositionalParametersSorter());
validatePositionalParameters(positionalParametersFields);

if (positionalParametersFields.isEmpty() && optionName2Field.isEmpty() && !hasCommandAnnotation) {
throw new InitializationException(command + " (" + command.getClass() +
") is not a command: it has no @Command, @Option or @Parameters annotations");
}
}

private void initParentCommand(Object parent) {
Expand Down Expand Up @@ -2970,9 +3009,13 @@ static void registerIfAvailable(Map<Class<?>, ITypeConverter<?>> registry, Trace
Method method = factory.getDeclaredMethod(factoryMethodName, paramTypes);
registry.put(cls, new ReflectionConverter(method, paramTypes));
} catch (Exception e) {
tracer.info("Could not register converter for %s: %s%n", fqcn, e.toString());
if (!traced.contains(fqcn)) {
tracer.debug("Could not register converter for %s: %s%n", fqcn, e.toString());
}
traced.add(fqcn);
}
}
static Set<String> traced = new HashSet<String>();
static class ReflectionConverter implements ITypeConverter<Object> {
private final Method method;
private Class<?>[] paramTypes;
Expand Down
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