    001package com.typesafe.config.impl;
    002
    003import java.beans.BeanInfo;
    004import java.beans.IntrospectionException;
    005import java.beans.Introspector;
    006import java.beans.PropertyDescriptor;
    007import java.lang.reflect.Field;
    008import java.lang.reflect.InvocationTargetException;
    009import java.lang.reflect.Method;
    010import java.lang.reflect.ParameterizedType;
    011import java.lang.reflect.Type;
    012import java.util.ArrayList;
    013import java.util.HashMap;
    014import java.util.List;
    015import java.util.Map;
    016import java.time.Duration;
    017
    018import com.typesafe.config.Config;
    019import com.typesafe.config.ConfigObject;
    020import com.typesafe.config.ConfigList;
    021import com.typesafe.config.ConfigException;
    022import com.typesafe.config.ConfigMemorySize;
    023import com.typesafe.config.ConfigValue;
    024import com.typesafe.config.ConfigValueType;
    025import com.typesafe.config.Optional;
    026
    027/**
    028 * Internal implementation detail, not ABI stable, do not touch.
    029 * For use only by the {@link com.typesafe.config} package.
    030 */
    031public class ConfigBeanImpl {
    032
    033    /**
    034     * This is public ONLY for use by the "config" package, DO NOT USE this ABI
    035     * may change.
    036     * @param <T> type of the bean
    037     * @param config config to use
    038     * @param clazz class of the bean
    039     * @return the bean instance
    040     */
    041    public static <T> T createInternal(Config config, Class<T> clazz) {
    042        if (((SimpleConfig)config).root().resolveStatus() != ResolveStatus.RESOLVED)
    043            throw new ConfigException.NotResolved(
    044                    "need to Config#resolve() a config before using it to initialize a bean, see the API docs for Config#resolve()");
    045
    046        Map<String, AbstractConfigValue> configProps = new HashMap<String, AbstractConfigValue>();
    047        Map<String, String> originalNames = new HashMap<String, String>();
    048        for (Map.Entry<String, ConfigValue> configProp : config.root().entrySet()) {
    049            String originalName = configProp.getKey();
    050            String camelName = ConfigImplUtil.toCamelCase(originalName);
    051            // if a setting is in there both as some hyphen name and the camel name,
    052            // the camel one wins
    053            if (originalNames.containsKey(camelName) && !originalName.equals(camelName)) {
    054                // if we aren't a camel name to start with, we lose.
    055                // if we are or we are the first matching key, we win.
    056            } else {
    057                configProps.put(camelName, (AbstractConfigValue) configProp.getValue());
    058                originalNames.put(camelName, originalName);
    059            }
    060        }
    061
    062        BeanInfo beanInfo = null;
    063        try {
    064            beanInfo = Introspector.getBeanInfo(clazz);
    065        } catch (IntrospectionException e) {
    066            throw new ConfigException.BadBean("Could not get bean information for class " + clazz.getName(), e);
    067        }
    068
    069        try {
    070            List<PropertyDescriptor> beanProps = new ArrayList<PropertyDescriptor>();
    071            for (PropertyDescriptor beanProp : beanInfo.getPropertyDescriptors()) {
    072                if (beanProp.getReadMethod() == null || beanProp.getWriteMethod() == null) {
    073                    continue;
    074                }
    075                beanProps.add(beanProp);
    076            }
    077
    078            // Try to throw all validation issues at once (this does not comprehensively
    079            // find every issue, but it should find common ones).
    080            List<ConfigException.ValidationProblem> problems = new ArrayList<ConfigException.ValidationProblem>();
    081            for (PropertyDescriptor beanProp : beanProps) {
    082                Method setter = beanProp.getWriteMethod();
    083                Class<?> parameterClass = setter.getParameterTypes()[0];
    084
    085                ConfigValueType expectedType = getValueTypeOrNull(parameterClass);
    086                if (expectedType != null) {
    087                    String name = originalNames.get(beanProp.getName());
    088                    if (name == null)
    089                        name = beanProp.getName();
    090                    Path path = Path.newKey(name);
    091                    AbstractConfigValue configValue = configProps.get(beanProp.getName());
    092                    if (configValue != null) {
    093                        SimpleConfig.checkValid(path, expectedType, configValue, problems);
    094                    } else {
    095                        if (!isOptionalProperty(clazz, beanProp)) {
    096                            SimpleConfig.addMissing(problems, expectedType, path, config.origin());
    097                        }
    098                    }
    099                }
    100            }
    101
    102            if (!problems.isEmpty()) {
    103                throw new ConfigException.ValidationFailed(problems);
    104            }
    105
    106            // Fill in the bean instance
    107            T bean = clazz.newInstance();
    108            for (PropertyDescriptor beanProp : beanProps) {
    109                Method setter = beanProp.getWriteMethod();
    110                Type parameterType = setter.getGenericParameterTypes()[0];
    111                Class<?> parameterClass = setter.getParameterTypes()[0];
    112                String configPropName = originalNames.get(beanProp.getName());
    113                // Is the property key missing in the config?
    114                if (configPropName == null) {
    115                    // If so, continue if the field is marked as @{link Optional}
    116                    if (isOptionalProperty(clazz, beanProp)) {
    117                        continue;
    118                    }
    119                    // Otherwise, raise a {@link Missing} exception right here
    120                    throw new ConfigException.Missing(beanProp.getName());
    121                }
    122                Object unwrapped = getValue(clazz, parameterType, parameterClass, config, configPropName);
    123                setter.invoke(bean, unwrapped);
    124            }
    125            return bean;
    126        } catch (InstantiationException e) {
    127            throw new ConfigException.BadBean(clazz.getName() + " needs a public no-args constructor to be used as a bean", e);
    128        } catch (IllegalAccessException e) {
    129            throw new ConfigException.BadBean(clazz.getName() + " getters and setters are not accessible, they must be for use as a bean", e);
    130        } catch (InvocationTargetException e) {
    131            throw new ConfigException.BadBean("Calling bean method on " + clazz.getName() + " caused an exception", e);
    132        }
    133    }
    134
    135    // we could magically make this work in many cases by doing
    136    // getAnyRef() (or getValue().unwrapped()), but anytime we
    137    // rely on that, we aren't doing the type conversions Config
    138    // usually does, and we will throw ClassCastException instead
    139    // of a nicer error message giving the name of the bad
    140    // setting. So, instead, we only support a limited number of
    141    // types plus you can always use Object, ConfigValue, Config,
    142    // ConfigObject, etc.  as an escape hatch.
    143    private static Object getValue(Class<?> beanClass, Type parameterType, Class<?> parameterClass, Config config,
    144            String configPropName) {
    145        if (parameterClass == Boolean.class || parameterClass == boolean.class) {
    146            return config.getBoolean(configPropName);
    147        } else if (parameterClass == Integer.class || parameterClass == int.class) {
    148            return config.getInt(configPropName);
    149        } else if (parameterClass == Double.class || parameterClass == double.class) {
    150            return config.getDouble(configPropName);
    151        } else if (parameterClass == Long.class || parameterClass == long.class) {
    152            return config.getLong(configPropName);
    153        } else if (parameterClass == String.class) {
    154            return config.getString(configPropName);
    155        } else if (parameterClass == Duration.class) {
    156            return config.getDuration(configPropName);
    157        } else if (parameterClass == ConfigMemorySize.class) {
    158            return config.getMemorySize(configPropName);
    159        } else if (parameterClass == Object.class) {
    160            return config.getAnyRef(configPropName);
    161        } else if (parameterClass == List.class) {
    162            return getListValue(beanClass, parameterType, parameterClass, config, configPropName);
    163        } else if (parameterClass == Map.class) {
    164            // we could do better here, but right now we don't.
    165            Type[] typeArgs = ((ParameterizedType)parameterType).getActualTypeArguments();
    166            if (typeArgs[0] != String.class || typeArgs[1] != Object.class) {
    167                throw new ConfigException.BadBean("Bean property '" + configPropName + "' of class " + beanClass.getName() + " has unsupported Map<" + typeArgs[0] + "," + typeArgs[1] + ">, only Map<String,Object> is supported right now");
    168            }
    169            return config.getObject(configPropName).unwrapped();
    170        } else if (parameterClass == Config.class) {
    171            return config.getConfig(configPropName);
    172        } else if (parameterClass == ConfigObject.class) {
    173            return config.getObject(configPropName);
    174        } else if (parameterClass == ConfigValue.class) {
    175            return config.getValue(configPropName);
    176        } else if (parameterClass == ConfigList.class) {
    177            return config.getList(configPropName);
    178        } else if (parameterClass.isEnum()) {
    179            @SuppressWarnings("unchecked")
    180            Enum enumValue = config.getEnum((Class<Enum>) parameterClass, configPropName);
    181            return enumValue;
    182        } else if (hasAtLeastOneBeanProperty(parameterClass)) {
    183            return createInternal(config.getConfig(configPropName), parameterClass);
    184        } else {
    185            throw new ConfigException.BadBean("Bean property " + configPropName + " of class " + beanClass.getName() + " has unsupported type " + parameterType);
    186        }
    187    }
    188
    189    private static Object getListValue(Class<?> beanClass, Type parameterType, Class<?> parameterClass, Config config, String configPropName) {
    190        Type elementType = ((ParameterizedType)parameterType).getActualTypeArguments()[0];
    191
    192        if (elementType == Boolean.class) {
    193            return config.getBooleanList(configPropName);
    194        } else if (elementType == Integer.class) {
    195            return config.getIntList(configPropName);
    196        } else if (elementType == Double.class) {
    197            return config.getDoubleList(configPropName);
    198        } else if (elementType == Long.class) {
    199            return config.getLongList(configPropName);
    200        } else if (elementType == String.class) {
    201            return config.getStringList(configPropName);
    202        } else if (elementType == Duration.class) {
    203            return config.getDurationList(configPropName);
    204        } else if (elementType == ConfigMemorySize.class) {
    205            return config.getMemorySizeList(configPropName);
    206        } else if (elementType == Object.class) {
    207            return config.getAnyRefList(configPropName);
    208        } else if (elementType == Config.class) {
    209            return config.getConfigList(configPropName);
    210        } else if (elementType == ConfigObject.class) {
    211            return config.getObjectList(configPropName);
    212        } else if (elementType == ConfigValue.class) {
    213            return config.getList(configPropName);
    214        } else if (((Class<?>) elementType).isEnum()) {
    215            @SuppressWarnings("unchecked")
    216            List<Enum> enumValues = config.getEnumList((Class<Enum>) elementType, configPropName);
    217            return enumValues;
    218        } else if (hasAtLeastOneBeanProperty((Class<?>) elementType)) {
    219            List<Object> beanList = new ArrayList<Object>();
    220            List<? extends Config> configList = config.getConfigList(configPropName);
    221            for (Config listMember : configList) {
    222                beanList.add(createInternal(listMember, (Class<?>) elementType));
    223            }
    224            return beanList;
    225        } else {
    226            throw new ConfigException.BadBean("Bean property '" + configPropName + "' of class " + beanClass.getName() + " has unsupported list element type " + elementType);
    227        }
    228    }
    229
    230    // null if we can't easily say; this is heuristic/best-effort
    231    private static ConfigValueType getValueTypeOrNull(Class<?> parameterClass) {
    232        if (parameterClass == Boolean.class || parameterClass == boolean.class) {
    233            return ConfigValueType.BOOLEAN;
    234        } else if (parameterClass == Integer.class || parameterClass == int.class) {
    235            return ConfigValueType.NUMBER;
    236        } else if (parameterClass == Double.class || parameterClass == double.class) {
    237            return ConfigValueType.NUMBER;
    238        } else if (parameterClass == Long.class || parameterClass == long.class) {
    239            return ConfigValueType.NUMBER;
    240        } else if (parameterClass == String.class) {
    241            return ConfigValueType.STRING;
    242        } else if (parameterClass == Duration.class) {
    243            return null;
    244        } else if (parameterClass == ConfigMemorySize.class) {
    245            return null;
    246        } else if (parameterClass == List.class) {
    247            return ConfigValueType.LIST;
    248        } else if (parameterClass == Map.class) {
    249            return ConfigValueType.OBJECT;
    250        } else if (parameterClass == Config.class) {
    251            return ConfigValueType.OBJECT;
    252        } else if (parameterClass == ConfigObject.class) {
    253            return ConfigValueType.OBJECT;
    254        } else if (parameterClass == ConfigList.class) {
    255            return ConfigValueType.LIST;
    256        } else {
    257            return null;
    258        }
    259    }
    260
    261    private static boolean hasAtLeastOneBeanProperty(Class<?> clazz) {
    262        BeanInfo beanInfo = null;
    263        try {
    264            beanInfo = Introspector.getBeanInfo(clazz);
    265        } catch (IntrospectionException e) {
    266            return false;
    267        }
    268
    269        for (PropertyDescriptor beanProp : beanInfo.getPropertyDescriptors()) {
    270            if (beanProp.getReadMethod() != null && beanProp.getWriteMethod() != null) {
    271                return true;
    272            }
    273        }
    274
    275        return false;
    276    }
    277
    278    private static boolean isOptionalProperty(Class beanClass, PropertyDescriptor beanProp) {
    279        Field field = getField(beanClass, beanProp.getName());
    280        return (field.getAnnotationsByType(Optional.class).length > 0);
    281    }
    282
    283    private static Field getField(Class beanClass, String fieldName) {
    284        try {
    285            Field field = beanClass.getDeclaredField(fieldName);
    286            field.setAccessible(true);
    287            return field;
    288        } catch (NoSuchFieldException e) {
    289            // Don't give up yet. Try to look for field in super class, if any.
    290        }
    291        beanClass = beanClass.getSuperclass();
    292        if (beanClass == null) {
    293            return null;
    294        }
    295        return getField(beanClass, fieldName);
    296    }
    297}