io.datarouter.binarydto.internal.BinaryDtoMetadataParser Maven / Gradle / Ivy
/*
* Copyright © 2009 HotPads ([email protected])
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.datarouter.binarydto.internal;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import io.datarouter.binarydto.dto.BaseBinaryDto;
import io.datarouter.scanner.Scanner;
public class BinaryDtoMetadataParser>{
private final T dto;
public BinaryDtoMetadataParser(T dto){
this.dto = dto;
}
public List listFields(){
return anyIndexSpecified()
? listFieldsByIndex()
: listFieldsAlphabetically();
}
private List listFieldsByIndex(){
Field[] fields = new Field[maxFieldIndex() + 1];
scanFields()
.map(BinaryDtoFieldMetadataParser::new)
.forEach(metadata -> {
int index = metadata.getRequiredIndex();
if(index < 0){
String message = String.format("index=%s cannot be negative", index);
throw new IllegalArgumentException(message);
}
if(fields[index] != null){
String message = String.format("index=%s already specified", index);
throw new IllegalArgumentException(message);
}
fields[index] = metadata.getField();
});
return Arrays.asList(fields);
}
private List listFieldsAlphabetically(){
return scanFields()
.each(field -> {
if(new BinaryDtoFieldMetadataParser<>(field).hasIndex()){
String message = String.format(
"Classes extending %s cannot have BinaryDtoField index specified. Field=%s",
getClass().getCanonicalName(),
field.getName());
throw new IllegalArgumentException(message);
}
})
.sort(Comparator.comparing(Field::getName))
.list();
}
private Scanner scanFields(){
return BinaryDtoReflectionTool.scanFieldsIncludingSuperclasses(dto.getClass());
}
private boolean anyIndexSpecified(){
return scanFields()
.map(BinaryDtoFieldMetadataParser::new)
.anyMatch(BinaryDtoFieldMetadataParser::hasIndex);
}
private int maxFieldIndex(){
return scanFields()
.map(BinaryDtoFieldMetadataParser::new)
.map(BinaryDtoFieldMetadataParser::getRequiredIndex)
.findMax(Comparator.naturalOrder())
.orElseThrow();
}
}