querqy.elasticsearch.ConfigUtils Maven / Gradle / Ivy

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package querqy.elasticsearch;

import org.elasticsearch.SpecialPermission;
import querqy.trie.TrieMap;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collection;
import java.util.HashSet;
import java.util.Map;
import java.util.Optional;

public interface ConfigUtils {


    static String getStringArg(final Map config, final String name, final String defaultValue) {
        final String value = (String) config.get(name);
        return value == null ? defaultValue : value;
    }

    static Optional getStringArg(final Map config, final String name) {
        return Optional.ofNullable((String) config.get(name));
    }

    static > Optional getEnumArg(final Map config, final String name,
                                                  final Class enumClass) {
        final String value = (String) config.get(name);
        return (value == null) ? Optional.empty() : Optional.of(Enum.valueOf(enumClass, value));
    }


    static  T getArg(final Map config, final String name, final T defaultValue) {
        return (T) config.getOrDefault(name, defaultValue);
    }

    static TrieMap getTrieSetArg(final Map config, final String name) {
        final TrieMap result = new TrieMap<>();
        final Collection collectionArg = (Collection) config.get(name);
        if (collectionArg != null) {
            for (final String word : new HashSet<>(collectionArg)) {
                result.put(word, Boolean.TRUE);
            }
        }
        return result;
    }

    static  V getInstanceFromArg(final Map config, final String name, final V defaultValue) {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPermission(new SpecialPermission());
        }


        return AccessController.doPrivileged(
            (PrivilegedAction) () -> {
                final String classField = (String) config.get(name);
                if (classField == null) {
                    return defaultValue;
                }

                final String className = classField.trim();
                if (className.isEmpty()) {
                    return defaultValue;
                }

                try {
                    return (V) Class.forName(className).getDeclaredConstructor().newInstance();
                } catch (final Exception e) {
                    throw new RuntimeException(e);
                }
            });

    }

}