CommentGetterFactory.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 CommentGetter}のインスタンスを作成する。
*
* @since 2.0
* @author T.TSUCHIE
*
*/
public class CommentGetterFactory {
private static final Logger log = LoggerFactory.getLogger(CommentGetterFactory.class);
/**
* フィールドのコメント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 コメント情報の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<CommentGetter> create(final Class<?> beanClass, final String fieldName) {
ArgUtils.notNull(beanClass, "beanClass");
ArgUtils.notEmpty(fieldName, "fieldName");
// フィールド Map commentsの場合
Optional<CommentGetter> CommentGetter = createMapField(beanClass, fieldName);
if(CommentGetter.isPresent()) {
return CommentGetter;
}
// setter メソッドの場合
CommentGetter = createMethod(beanClass, fieldName);
if(CommentGetter.isPresent()) {
return CommentGetter;
}
// フィールド + commentの場合
CommentGetter = createField(beanClass, fieldName);
if(CommentGetter.isPresent()) {
return CommentGetter;
}
return Optional.empty();
}
private Optional<CommentGetter> createMapField(final Class<?> beanClass, final String fieldName) {
final Field commentsField;
try {
commentsField = beanClass.getDeclaredField("comments");
commentsField.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(commentsField.getType())) {
return Optional.empty();
}
final ParameterizedType type = (ParameterizedType) commentsField.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 CommentGetter() {
@SuppressWarnings("unchecked")
@Override
public Optional<String> get(final Object beanObj) {
ArgUtils.notNull(beanObj, "beanObj");
try {
Map<String, String> commentsMapObj = (Map<String, String>) commentsField.get(beanObj);
if(commentsMapObj == null) {
return Optional.empty();
}
return Optional.ofNullable(commentsMapObj.get(fieldName));
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new RuntimeException("fail access comments field.", e);
}
}
});
} else {
// タイプが一致しない場合
log.warn("not match generics type of comments. key type:{}, value type:{}.", keyType.getName(), valueType.getName());
return Optional.empty();
}
}
private Optional<CommentGetter> createMethod(final Class<?> beanClass, final String fieldName) {
final String commentMethodName = "get" + Utils.capitalize(fieldName) + "Comment";
final Method method;
try {
method = beanClass.getDeclaredMethod(commentMethodName);
method.setAccessible(true);
} catch (NoSuchMethodException | SecurityException e) {
return Optional.empty();
}
if(method.getReturnType().equals(String.class)) {
return Optional.of(new CommentGetter() {
@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 comments getter method.", e);
}
}
});
}
return Optional.empty();
}
private Optional<CommentGetter> createField(final Class<?> beanClass, final String fieldName) {
final String commentFieldName = fieldName + "Comment";
final Field commentField;
try {
commentField = beanClass.getDeclaredField(commentFieldName);
commentField.setAccessible(true);
} catch (NoSuchFieldException | SecurityException e) {
return Optional.empty();
}
if(commentField.getType().equals(String.class)) {
return Optional.of(new CommentGetter() {
@Override
public Optional<String> get(final Object beanObj) {
ArgUtils.notNull(beanObj, "beanObj");
try {
final String comment = (String) commentField.get(beanObj);
return Optional.ofNullable(comment);
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new RuntimeException("fail access comment field.", e);
}
}
});
}
return Optional.empty();
}
}