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.HashSet;
015import java.util.List;
016import java.util.Map;
017import java.time.Duration;
018import java.util.Set;
019
020import com.typesafe.config.Config;
021import com.typesafe.config.ConfigObject;
022import com.typesafe.config.ConfigList;
023import com.typesafe.config.ConfigException;
024import com.typesafe.config.ConfigMemorySize;
025import com.typesafe.config.ConfigValue;
026import com.typesafe.config.ConfigValueType;
027import com.typesafe.config.Optional;
028
029/**
030 * Internal implementation detail, not ABI stable, do not touch.
031 * For use only by the {@link com.typesafe.config} package.
032 */
033public class ConfigBeanImpl {
034
035    /**
036     * This is public ONLY for use by the "config" package, DO NOT USE this ABI
037     * may change.
038     * @param <T> type of the bean
039     * @param config config to use
040     * @param clazz class of the bean
041     * @return the bean instance
042     */
043    public static <T> T createInternal(Config config, Class<T> clazz) {
044        if (((SimpleConfig)config).root().resolveStatus() != ResolveStatus.RESOLVED)
045            throw new ConfigException.NotResolved(
046                    "need to Config#resolve() a config before using it to initialize a bean, see the API docs for Config#resolve()");
047
048        Map<String, AbstractConfigValue> configProps = new HashMap<String, AbstractConfigValue>();
049        Map<String, String> originalNames = new HashMap<String, String>();
050        for (Map.Entry<String, ConfigValue> configProp : config.root().entrySet()) {
051            String originalName = configProp.getKey();
052            String camelName = ConfigImplUtil.toCamelCase(originalName);
053            // if a setting is in there both as some hyphen name and the camel name,
054            // the camel one wins
055            if (originalNames.containsKey(camelName) && !originalName.equals(camelName)) {
056                // if we aren't a camel name to start with, we lose.
057                // if we are or we are the first matching key, we win.
058            } else {
059                configProps.put(camelName, (AbstractConfigValue) configProp.getValue());
060                originalNames.put(camelName, originalName);
061            }
062        }
063
064        BeanInfo beanInfo = null;
065        try {
066            beanInfo = Introspector.getBeanInfo(clazz);
067        } catch (IntrospectionException e) {
068            throw new ConfigException.BadBean("Could not get bean information for class " + clazz.getName(), e);
069        }
070
071        try {
072            List<PropertyDescriptor> beanProps = new ArrayList<PropertyDescriptor>();
073            for (PropertyDescriptor beanProp : beanInfo.getPropertyDescriptors()) {
074                if (beanProp.getReadMethod() == null || beanProp.getWriteMethod() == null) {
075                    continue;
076                }
077                beanProps.add(beanProp);
078            }
079
080            // Try to throw all validation issues at once (this does not comprehensively
081            // find every issue, but it should find common ones).
082            List<ConfigException.ValidationProblem> problems = new ArrayList<ConfigException.ValidationProblem>();
083            for (PropertyDescriptor beanProp : beanProps) {
084                Method setter = beanProp.getWriteMethod();
085                Class<?> parameterClass = setter.getParameterTypes()[0];
086
087                ConfigValueType expectedType = getValueTypeOrNull(parameterClass);
088                if (expectedType != null) {
089                    String name = originalNames.get(beanProp.getName());
090                    if (name == null)
091                        name = beanProp.getName();
092                    Path path = Path.newKey(name);
093                    AbstractConfigValue configValue = configProps.get(beanProp.getName());
094                    if (configValue != null) {
095                        SimpleConfig.checkValid(path, expectedType, configValue, problems);
096                    } else {
097                        if (!isOptionalProperty(clazz, beanProp)) {
098                            SimpleConfig.addMissing(problems, expectedType, path, config.origin());
099                        }
100                    }
101                }
102            }
103
104            if (!problems.isEmpty()) {
105                throw new ConfigException.ValidationFailed(problems);
106            }
107
108            // Fill in the bean instance
109            T bean = clazz.newInstance();
110            for (PropertyDescriptor beanProp : beanProps) {
111                Method setter = beanProp.getWriteMethod();
112                Type parameterType = setter.getGenericParameterTypes()[0];
113                Class<?> parameterClass = setter.getParameterTypes()[0];
114                String configPropName = originalNames.get(beanProp.getName());
115                // Is the property key missing in the config?
116                if (configPropName == null) {
117                    // If so, continue if the field is marked as @{link Optional}
118                    if (isOptionalProperty(clazz, beanProp)) {
119                        continue;
120                    }
121                    // Otherwise, raise a {@link Missing} exception right here
122                    throw new ConfigException.Missing(beanProp.getName());
123                }
124                Object unwrapped = getValue(clazz, parameterType, parameterClass, config, configPropName);
125                setter.invoke(bean, unwrapped);
126            }
127            return bean;
128        } catch (InstantiationException e) {
129            throw new ConfigException.BadBean(clazz.getName() + " needs a public no-args constructor to be used as a bean", e);
130        } catch (IllegalAccessException e) {
131            throw new ConfigException.BadBean(clazz.getName() + " getters and setters are not accessible, they must be for use as a bean", e);
132        } catch (InvocationTargetException e) {
133            throw new ConfigException.BadBean("Calling bean method on " + clazz.getName() + " caused an exception", e);
134        }
135    }
136
137    // we could magically make this work in many cases by doing
138    // getAnyRef() (or getValue().unwrapped()), but anytime we
139    // rely on that, we aren't doing the type conversions Config
140    // usually does, and we will throw ClassCastException instead
141    // of a nicer error message giving the name of the bad
142    // setting. So, instead, we only support a limited number of
143    // types plus you can always use Object, ConfigValue, Config,
144    // ConfigObject, etc.  as an escape hatch.
145    private static Object getValue(Class<?> beanClass, Type parameterType, Class<?> parameterClass, Config config,
146            String configPropName) {
147        if (parameterClass == Boolean.class || parameterClass == boolean.class) {
148            return config.getBoolean(configPropName);
149        } else if (parameterClass == Integer.class || parameterClass == int.class) {
150            return config.getInt(configPropName);
151        } else if (parameterClass == Double.class || parameterClass == double.class) {
152            return config.getDouble(configPropName);
153        } else if (parameterClass == Long.class || parameterClass == long.class) {
154            return config.getLong(configPropName);
155        } else if (parameterClass == String.class) {
156            return config.getString(configPropName);
157        } else if (parameterClass == Duration.class) {
158            return config.getDuration(configPropName);
159        } else if (parameterClass == ConfigMemorySize.class) {
160            return config.getMemorySize(configPropName);
161        } else if (parameterClass == Object.class) {
162            return config.getAnyRef(configPropName);
163        } else if (parameterClass == List.class) {
164            return getListValue(beanClass, parameterType, parameterClass, config, configPropName);
165        } else if (parameterClass == Set.class) {
166            return getSetValue(beanClass, parameterType, parameterClass, config, configPropName);
167        } else if (parameterClass == Map.class) {
168            // we could do better here, but right now we don't.
169            Type[] typeArgs = ((ParameterizedType)parameterType).getActualTypeArguments();
170            if (typeArgs[0] != String.class || typeArgs[1] != Object.class) {
171                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");
172            }
173            return config.getObject(configPropName).unwrapped();
174        } else if (parameterClass == Config.class) {
175            return config.getConfig(configPropName);
176        } else if (parameterClass == ConfigObject.class) {
177            return config.getObject(configPropName);
178        } else if (parameterClass == ConfigValue.class) {
179            return config.getValue(configPropName);
180        } else if (parameterClass == ConfigList.class) {
181            return config.getList(configPropName);
182        } else if (parameterClass.isEnum()) {
183            @SuppressWarnings("unchecked")
184            Enum enumValue = config.getEnum((Class<Enum>) parameterClass, configPropName);
185            return enumValue;
186        } else if (hasAtLeastOneBeanProperty(parameterClass)) {
187            return createInternal(config.getConfig(configPropName), parameterClass);
188        } else {
189            throw new ConfigException.BadBean("Bean property " + configPropName + " of class " + beanClass.getName() + " has unsupported type " + parameterType);
190        }
191    }
192
193    private static Object getSetValue(Class<?> beanClass, Type parameterType, Class<?> parameterClass, Config config, String configPropName) {
194        return new HashSet((List) getListValue(beanClass, parameterType, parameterClass, config, configPropName));
195    }
196
197    private static Object getListValue(Class<?> beanClass, Type parameterType, Class<?> parameterClass, Config config, String configPropName) {
198        Type elementType = ((ParameterizedType)parameterType).getActualTypeArguments()[0];
199
200        if (elementType == Boolean.class) {
201            return config.getBooleanList(configPropName);
202        } else if (elementType == Integer.class) {
203            return config.getIntList(configPropName);
204        } else if (elementType == Double.class) {
205            return config.getDoubleList(configPropName);
206        } else if (elementType == Long.class) {
207            return config.getLongList(configPropName);
208        } else if (elementType == String.class) {
209            return config.getStringList(configPropName);
210        } else if (elementType == Duration.class) {
211            return config.getDurationList(configPropName);
212        } else if (elementType == ConfigMemorySize.class) {
213            return config.getMemorySizeList(configPropName);
214        } else if (elementType == Object.class) {
215            return config.getAnyRefList(configPropName);
216        } else if (elementType == Config.class) {
217            return config.getConfigList(configPropName);
218        } else if (elementType == ConfigObject.class) {
219            return config.getObjectList(configPropName);
220        } else if (elementType == ConfigValue.class) {
221            return config.getList(configPropName);
222        } else if (((Class<?>) elementType).isEnum()) {
223            @SuppressWarnings("unchecked")
224            List<Enum> enumValues = config.getEnumList((Class<Enum>) elementType, configPropName);
225            return enumValues;
226        } else if (hasAtLeastOneBeanProperty((Class<?>) elementType)) {
227            List<Object> beanList = new ArrayList<Object>();
228            List<? extends Config> configList = config.getConfigList(configPropName);
229            for (Config listMember : configList) {
230                beanList.add(createInternal(listMember, (Class<?>) elementType));
231            }
232            return beanList;
233        } else {
234            throw new ConfigException.BadBean("Bean property '" + configPropName + "' of class " + beanClass.getName() + " has unsupported list element type " + elementType);
235        }
236    }
237
238    // null if we can't easily say; this is heuristic/best-effort
239    private static ConfigValueType getValueTypeOrNull(Class<?> parameterClass) {
240        if (parameterClass == Boolean.class || parameterClass == boolean.class) {
241            return ConfigValueType.BOOLEAN;
242        } else if (parameterClass == Integer.class || parameterClass == int.class) {
243            return ConfigValueType.NUMBER;
244        } else if (parameterClass == Double.class || parameterClass == double.class) {
245            return ConfigValueType.NUMBER;
246        } else if (parameterClass == Long.class || parameterClass == long.class) {
247            return ConfigValueType.NUMBER;
248        } else if (parameterClass == String.class) {
249            return ConfigValueType.STRING;
250        } else if (parameterClass == Duration.class) {
251            return null;
252        } else if (parameterClass == ConfigMemorySize.class) {
253            return null;
254        } else if (parameterClass == List.class) {
255            return ConfigValueType.LIST;
256        } else if (parameterClass == Map.class) {
257            return ConfigValueType.OBJECT;
258        } else if (parameterClass == Config.class) {
259            return ConfigValueType.OBJECT;
260        } else if (parameterClass == ConfigObject.class) {
261            return ConfigValueType.OBJECT;
262        } else if (parameterClass == ConfigList.class) {
263            return ConfigValueType.LIST;
264        } else {
265            return null;
266        }
267    }
268
269    private static boolean hasAtLeastOneBeanProperty(Class<?> clazz) {
270        BeanInfo beanInfo = null;
271        try {
272            beanInfo = Introspector.getBeanInfo(clazz);
273        } catch (IntrospectionException e) {
274            return false;
275        }
276
277        for (PropertyDescriptor beanProp : beanInfo.getPropertyDescriptors()) {
278            if (beanProp.getReadMethod() != null && beanProp.getWriteMethod() != null) {
279                return true;
280            }
281        }
282
283        return false;
284    }
285
286    private static boolean isOptionalProperty(Class beanClass, PropertyDescriptor beanProp) {
287        Field field = getField(beanClass, beanProp.getName());
288        return field != null ? field.getAnnotationsByType(Optional.class).length > 0 : beanProp.getReadMethod().getAnnotationsByType(Optional.class).length > 0;
289    }
290
291    private static Field getField(Class beanClass, String fieldName) {
292        try {
293            Field field = beanClass.getDeclaredField(fieldName);
294            field.setAccessible(true);
295            return field;
296        } catch (NoSuchFieldException e) {
297            // Don't give up yet. Try to look for field in super class, if any.
298        }
299        beanClass = beanClass.getSuperclass();
300        if (beanClass == null) {
301            return null;
302        }
303        return getField(beanClass, fieldName);
304    }
305}