LabelGetterFactory.java
package com.gh.mygreen.xlsmapper.fieldaccessor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.util.Map;
import java.util.Optional;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.gh.mygreen.xlsmapper.util.ArgUtils;
import com.gh.mygreen.xlsmapper.util.Utils;
/**
* {@link LabelGetter}のインスタンスを作成する。
*
* @since 2.0
* @author T.TSUCHIE
*
*/
public class LabelGetterFactory {
private static final Logger log = LoggerFactory.getLogger(LabelGetterFactory.class);
/**
* フィールドのラベル情報を取得するためのアクセッサを作成します。
* @param beanClass フィールドが定義されているクラス情報
* @param fieldName フィールドの名称
* @return ラベル情報のgetterが存在しない場合は空を返す。
* @throws IllegalArgumentException {@literal beanClass == null or fieldName == null}
* @throws IllegalArgumentException {@literal fieldName.isEmpty() = true}
*/
public Optional<LabelGetter> create(final Class<?> beanClass, final String fieldName) {
ArgUtils.notNull(beanClass, "beanClass");
ArgUtils.notEmpty(fieldName, "fieldName");
// フィールド Map labelsの場合
Optional<LabelGetter> LabelGetter = createMapField(beanClass, fieldName);
if(LabelGetter.isPresent()) {
return LabelGetter;
}
// setter メソッドの場合
LabelGetter = createMethod(beanClass, fieldName);
if(LabelGetter.isPresent()) {
return LabelGetter;
}
// フィールド + labelの場合
LabelGetter = createField(beanClass, fieldName);
if(LabelGetter.isPresent()) {
return LabelGetter;
}
return Optional.empty();
}
private Optional<LabelGetter> createMapField(final Class<?> beanClass, final String fieldName) {
final Field labelsField;
try {
labelsField = beanClass.getDeclaredField("labels");
labelsField.setAccessible(true);
} catch (NoSuchFieldException | SecurityException e) {
// フィールドが見つからない場合は、何もしない。
return Optional.empty();
}
if(!Map.class.isAssignableFrom(labelsField.getType())) {
return Optional.empty();
}
final ParameterizedType type = (ParameterizedType) labelsField.getGenericType();
final Class<?> keyType = (Class<?>) type.getActualTypeArguments()[0];
final Class<?> valueType = (Class<?>) type.getActualTypeArguments()[1];
if(keyType.equals(String.class) && valueType.equals(String.class)) {
return Optional.of(new LabelGetter() {
@SuppressWarnings("unchecked")
@Override
public Optional<String> get(final Object beanObj) {
ArgUtils.notNull(beanObj, "beanObj");
try {
Map<String, String> labelsMapObj = (Map<String, String>) labelsField.get(beanObj);
if(labelsMapObj == null) {
return Optional.empty();
}
return Optional.ofNullable(labelsMapObj.get(fieldName));
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new RuntimeException("fail access labels field.", e);
}
}
});
} else {
// タイプが一致しない場合
log.warn("not match generics type of labels. key type:{}, value type:{}.", keyType.getName(), valueType.getName());
return Optional.empty();
}
}
private Optional<LabelGetter> createMethod(final Class<?> beanClass, final String fieldName) {
final String labelMethodName = "get" + Utils.capitalize(fieldName) + "Label";
final Method method;
try {
method = beanClass.getDeclaredMethod(labelMethodName);
method.setAccessible(true);
} catch (NoSuchMethodException | SecurityException e) {
return Optional.empty();
}
if(method.getReturnType().equals(String.class)) {
return Optional.of(new LabelGetter() {
@Override
public Optional<String> get(final Object beanObj) {
ArgUtils.notNull(beanObj, "beanObj");
try {
final String address = (String)method.invoke(beanObj);
return Optional.ofNullable(address);
} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
throw new RuntimeException("fail access labels getter method.", e);
}
}
});
}
return Optional.empty();
}
private Optional<LabelGetter> createField(final Class<?> beanClass, final String fieldName) {
final String labelFieldName = fieldName + "Label";
final Field labelField;
try {
labelField = beanClass.getDeclaredField(labelFieldName);
labelField.setAccessible(true);
} catch (NoSuchFieldException | SecurityException e) {
return Optional.empty();
}
if(labelField.getType().equals(String.class)) {
return Optional.of(new LabelGetter() {
@Override
public Optional<String> get(final Object beanObj) {
ArgUtils.notNull(beanObj, "beanObj");
try {
final String address = (String) labelField.get(beanObj);
return Optional.ofNullable(address);
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new RuntimeException("fail access label field.", e);
}
}
});
}
return Optional.empty();
}
}