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Java library to map flat record - ResultSet, csv - to java object with minimum configuration and low footprint.
package org.simpleflatmapper.map.mapper;
import org.simpleflatmapper.map.MappingContext;
import org.simpleflatmapper.map.MappingException;
import org.simpleflatmapper.map.SourceFieldMapper;
import org.simpleflatmapper.util.Enumerable;
import org.simpleflatmapper.util.ErrorHelper;
import org.simpleflatmapper.util.Function;
import org.simpleflatmapper.util.Predicate;
public class DiscriminatorEnumerable implements Enumerable {
private final PredicatedMapperWithContext[] discriminatorMappers;
private final Enumerable sourceEnumerable;
private final Function errorMessageGenerator;
private T currentValue;
private T nextValue;
private SourceFieldMapper currentMapper;
private MappingContext currentMappingContext;
public DiscriminatorEnumerable(
PredicatedMapperWithContext[] discriminatorMappers,
Enumerable sourceEnumerable,
Function errorMessageGenerator) {
this.discriminatorMappers = discriminatorMappers;
this.sourceEnumerable = sourceEnumerable;
this.errorMessageGenerator = errorMessageGenerator;
}
@Override
public boolean next() {
try {
currentValue = nextValue;
nextValue = null;
while (sourceEnumerable.next()) {
checkMapper();
S source = sourceEnumerable.currentValue();
if (currentMappingContext.broke(source)) {
if (currentValue == null) {
currentValue = currentMapper.map(source, currentMappingContext);
} else {
nextValue = currentMapper.map(source, currentMappingContext);
return true;
}
} else {
currentMapper.mapTo(source, currentValue, currentMappingContext);
}
}
return currentValue != null;
} catch (Exception e) {
ErrorHelper.rethrow(e);
return false;
}
}
public T currentValue() {
return currentValue;
}
private void checkMapper() {
for(PredicatedMapperWithContext pmm : discriminatorMappers ) {
if (pmm.predicate.test(sourceEnumerable.currentValue())) {
if (pmm.mapper != currentMapper) {
markAsBroken();
currentMapper = pmm.mapper;
currentMappingContext = pmm.mappingContext;
}
return;
}
}
mapperNotFound();
}
private void mapperNotFound() {
CharSequence errorMessage = errorMessageGenerator.apply(sourceEnumerable.currentValue());
throw new MappingException("No mapper found for " + errorMessage);
}
private void markAsBroken() {
for(PredicatedMapperWithContext pmm : discriminatorMappers ) {
pmm.mappingContext.markAsBroken();
}
}
public static class PredicatedMapperWithContext {
private final Predicate predicate;
private final SourceFieldMapper mapper;
private final MappingContext mappingContext;
public PredicatedMapperWithContext(Predicate predicate, SourceFieldMapper mapper, MappingContext mappingContext) {
this.predicate = predicate;
this.mapper = mapper;
this.mappingContext = mappingContext;
}
}
}