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The Fastnate Data Importer for offline SQL generation
package org.fastnate.data.csv;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import lombok.Getter;
import lombok.Setter;
import org.apache.commons.lang.ClassUtils;
import org.apache.commons.lang.StringUtils;
import org.fastnate.data.DataProvider;
import org.fastnate.data.util.ClassUtil;
import org.fastnate.generator.EntitySqlGenerator;
import org.fastnate.generator.context.EntityClass;
import org.fastnate.generator.context.GeneratorContext;
import org.fastnate.generator.context.ModelException;
import org.fastnate.generator.context.Property;
import org.fastnate.generator.context.SingularProperty;
/**
* Base class for converters that create SQL files from CSV files.
*
* @author Tobias Liefke
*
* @param
* The type of the generated objects
*/
public abstract class AbstractCsvDataProvider extends AbstractCsvReader implements DataProvider {
private static final Map, CsvPropertyConverter> PROPERTY_CONVERTER = new HashMap<>();
static {
PROPERTY_CONVERTER.put(Number.class, new CsvNumberConverter());
PROPERTY_CONVERTER.put(Boolean.class, new CsvBooleanConverter());
PROPERTY_CONVERTER.put(Date.class, new CsvDateConverter());
PROPERTY_CONVERTER.put(Enum.class, new CsvEnumConverter());
PROPERTY_CONVERTER.put(Character.class, new CsvCharacterConverter());
}
@Getter
private final Collection entities = new ArrayList<>();
private final Map> columnConverter = new HashMap<>();
private final Map columnProperties = new HashMap<>();
/** Indicates to ignore any column that can't be mapped to a property. */
@Getter
@Setter
private boolean ignoreUnknownColumns;
/**
* Initializes the converter from a path.
*
* @param importPath
* the path to a CSV file or to a directory that contains the *.csv files
*/
protected AbstractCsvDataProvider(final File importPath) {
super(importPath);
}
/**
* Defines the mapping from a column name to a property name.
*
* Only necessary, if column name is not equal to property name
*
* @param column
* the name of the column
* @param property
* the name of the property
*/
public void addColumnMapping(final String column, final String property) {
this.columnProperties.put(column, property);
}
/**
* Registers the converter to use for a specific column.
*
* Only nessecary, if the default converters are not enough for a specific column.
*
* @param column
* the name of the column
* @param converter
* used to convert that column from CSV to a Java value
*/
public void addConverter(final String column, final CsvPropertyConverter converter) {
this.columnConverter.put(column, converter);
}
/**
* Converts a column value to a property value and sets that property for an entity.
*
* @param entity
* the entity to modify
* @param column
* the name of the current column
* @param value
* the value of the property (converts the property, if nessecary)
* @return {@code true} if an appropriate property was found, {@code false} if a matching property was not found and
* {@code #isIgnoreUnknownColumns()} is {@code true}
*
* @throws IllegalArgumentException
* if a matching property was not found or the was not converted
*/
protected boolean applyColumn(final E entity, final String column, final String value) {
String property = this.columnProperties.get(column);
if (property == null) {
property = column;
}
final String setter = "set" + StringUtils.capitalize(property);
try {
// Try to find method
for (final Method method : entity.getClass().getMethods()) {
if (method.getName().equals(setter) && method.getParameterTypes().length == 1
&& !Modifier.isStatic(method.getModifiers())) {
// Now convert and apply to property
method.invoke(entity, convertColumn(column, method.getParameterTypes()[0], value));
return true;
}
}
if (!this.ignoreUnknownColumns) {
throw new IllegalArgumentException("Could not find a public method '" + setter + "' in "
+ entity.getClass());
}
return false;
} catch (final IllegalAccessException | InvocationTargetException e) {
throw new IllegalArgumentException(e);
}
}
/**
* Starts the generation of the SQL file from the list of CSV files.
*/
@Override
public void buildEntities() throws IOException {
this.entities.addAll(readImportFiles());
}
/**
* Tries to convert the given string to a value of the given type for the given column.
*
* @param column
* the name of the column
* @param targetType
* the target type
* @param value
* the string representation of the value
* @return the value for the property
*/
@SuppressWarnings("unchecked")
protected T convertColumn(final String column, final Class targetType, final String value) {
CsvPropertyConverter converter = (CsvPropertyConverter) this.columnConverter.get(column);
if (converter == null) {
if (String.class == targetType) {
return (T) value;
}
converter = findConverter(targetType);
if (converter == null) {
throw new IllegalArgumentException("Could not find a converter for " + targetType);
}
}
return (T) converter.convert(targetType, value);
}
/**
* Builds one or more entities from the given row.
*
* @param row
* contains the mapping from the header names to the current row data
* @return the list of entities from that row
*/
@Override
protected Collection createEntities(final Map row) {
return Collections.singleton(createEntity(row));
}
/**
* Creates a new empty entity for the current converter.
*
* Used by the default implementation of {@link #createEntities(Map)}.
*
* @return the new entity
*/
@SuppressWarnings("unchecked")
protected E createEntity() {
try {
return getEntityClass().getConstructor().newInstance();
} catch (final InstantiationException | IllegalAccessException | InvocationTargetException e) {
throw new IllegalStateException(e);
} catch (final NoSuchMethodException e) {
throw new ModelException("Could not find public no-arg constructor for " + getEntityClass(), e);
}
}
/**
* Builds one entity from the given row.
*
* @param row
* contains the mapping from the header names to the current row data
* @return the created and filled entity
*/
protected E createEntity(final Map row) {
final E entity = createEntity();
for (final Map.Entry column : row.entrySet()) {
applyColumn(entity, column.getKey(), column.getValue());
}
return entity;
}
@SuppressWarnings("unchecked")
private CsvPropertyConverter findConverter(final Class targetType) {
if (targetType == null) {
return null;
}
if (targetType.isPrimitive()) {
return findConverter(ClassUtils.primitiveToWrapper(targetType));
}
CsvPropertyConverter converter = (CsvPropertyConverter) PROPERTY_CONVERTER
.get(targetType);
if (converter == null) {
converter = findConverter(targetType.getSuperclass());
if (converter == null) {
for (final Class interf : targetType.getInterfaces()) {
converter = findConverter((Class) interf);
if (converter != null) {
return converter;
}
}
}
}
return converter;
}
/**
* The class of the created entities.
*
* @return the entity class
*/
protected Class getEntityClass() {
return ClassUtil.getActualTypeBinding(getClass(), AbstractCsvDataProvider.class, 0);
}
/**
* Defaults to 0.
*/
@Override
public int getOrder() {
return 0;
}
/**
* Maps the table columns of the singular properties to the CSV columns.
*
* Useful if the CSV file is a database export.
*/
protected void useTableColumns() {
final EntityClass description = new GeneratorContext().getDescription(getEntityClass());
for (final Property property : description.getAllProperties()) {
if (property instanceof SingularProperty) {
final SingularProperty singularProperty = (SingularProperty) property;
if (singularProperty.isTableColumn() && singularProperty.getColumn() != null) {
this.columnProperties.put(singularProperty.getColumn(), singularProperty.getAttribute().getName());
}
}
}
}
/**
* Writes all created entities.
*/
@Override
public void writeEntities(final EntitySqlGenerator sqlGenerator) throws IOException {
sqlGenerator.write(this.entities);
}
}