org.junit.jupiter.params.converter.DefaultArgumentConverter Maven / Gradle / Ivy
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/*
* Copyright 2015-2020 the original author or authors.
*
* All rights reserved. This program and the accompanying materials are
* made available under the terms of the Eclipse Public License v2.0 which
* accompanies this distribution and is available at
*
* https://www.eclipse.org/legal/epl-v20.html
*/
package org.junit.jupiter.params.converter;
import static java.util.Arrays.asList;
import static java.util.Collections.unmodifiableList;
import static java.util.Collections.unmodifiableMap;
import static org.apiguardian.api.API.Status.INTERNAL;
import static org.junit.platform.commons.util.ReflectionUtils.getWrapperType;
import java.io.File;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.nio.charset.Charset;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Duration;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.MonthDay;
import java.time.OffsetDateTime;
import java.time.OffsetTime;
import java.time.Period;
import java.time.Year;
import java.time.YearMonth;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.util.Collections;
import java.util.Currency;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.UUID;
import java.util.function.Function;
import org.apiguardian.api.API;
import org.junit.platform.commons.util.Preconditions;
import org.junit.platform.commons.util.ReflectionUtils;
/**
* {@code DefaultArgumentConverter} is the default implementation of the
* {@link ArgumentConverter} API.
*
* The {@code DefaultArgumentConverter} is able to convert from strings to a
* number of primitive types and their corresponding wrapper types (Byte, Short,
* Integer, Long, Float, and Double), date and time types from the
* {@code java.time} package, and some additional common Java types such as
* {@link File}, {@link BigDecimal}, {@link BigInteger}, {@link Currency},
* {@link Locale}, {@link URI}, {@link URL}, {@link UUID}, etc.
*
*
If the source and target types are identical the source object will not
* be modified.
*
* @since 5.0
* @see org.junit.jupiter.params.converter.ArgumentConverter
*/
@API(status = INTERNAL, since = "5.0")
public class DefaultArgumentConverter extends SimpleArgumentConverter {
public static final DefaultArgumentConverter INSTANCE = new DefaultArgumentConverter();
private static final List stringToObjectConverters = unmodifiableList(asList( //
new StringToPrimitiveConverter(), //
new StringToEnumConverter(), //
new StringToJavaTimeConverter(), //
new StringToCommonJavaTypesConverter(), //
new FallbackStringToObjectConverter() //
));
private DefaultArgumentConverter() {
// nothing to initialize
}
@Override
public Object convert(Object source, Class targetType) {
if (source == null) {
if (targetType.isPrimitive()) {
throw new ArgumentConversionException(
"Cannot convert null to primitive value of type " + targetType.getName());
}
return null;
}
if (ReflectionUtils.isAssignableTo(source, targetType)) {
return source;
}
return convertToTargetType(source, toWrapperType(targetType));
}
private Object convertToTargetType(Object source, Class targetType) {
if (source instanceof String) {
Optional converter = stringToObjectConverters.stream().filter(
candidate -> candidate.canConvert(targetType)).findFirst();
if (converter.isPresent()) {
try {
return converter.get().convert((String) source, targetType);
}
catch (Exception ex) {
if (ex instanceof ArgumentConversionException) {
// simply rethrow it
throw (ArgumentConversionException) ex;
}
// else
throw new ArgumentConversionException(
"Failed to convert String \"" + source + "\" to type " + targetType.getName(), ex);
}
}
}
throw new ArgumentConversionException("No implicit conversion to convert object of type "
+ source.getClass().getName() + " to type " + targetType.getName());
}
private static Class toWrapperType(Class targetType) {
Class wrapperType = getWrapperType(targetType);
return wrapperType != null ? wrapperType : targetType;
}
interface StringToObjectConverter {
boolean canConvert(Class targetType);
Object convert(String source, Class targetType) throws Exception;
}
private static class StringToPrimitiveConverter implements StringToObjectConverter {
private static final Map, Function> CONVERTERS;
static {
Map, Function> converters = new HashMap<>();
converters.put(Boolean.class, Boolean::valueOf);
converters.put(Character.class, source -> {
Preconditions.condition(source.length() == 1, () -> "String must have length of 1: " + source);
return source.charAt(0);
});
converters.put(Byte.class, Byte::decode);
converters.put(Short.class, Short::decode);
converters.put(Integer.class, Integer::decode);
converters.put(Long.class, Long::decode);
converters.put(Float.class, Float::valueOf);
converters.put(Double.class, Double::valueOf);
CONVERTERS = unmodifiableMap(converters);
}
@Override
public boolean canConvert(Class targetType) {
return CONVERTERS.containsKey(targetType);
}
@Override
public Object convert(String source, Class targetType) {
return CONVERTERS.get(targetType).apply(source);
}
}
private static class StringToEnumConverter implements StringToObjectConverter {
@Override
public boolean canConvert(Class targetType) {
return targetType.isEnum();
}
@Override
public Object convert(String source, Class targetType) throws Exception {
return valueOf(targetType, source);
}
@SuppressWarnings({ "unchecked", "rawtypes" })
private Object valueOf(Class targetType, String source) {
return Enum.valueOf(targetType, source);
}
}
private static class StringToJavaTimeConverter implements StringToObjectConverter {
private static final Map, Function> CONVERTERS;
static {
Map, Function> converters = new HashMap<>();
converters.put(Duration.class, Duration::parse);
converters.put(Instant.class, Instant::parse);
converters.put(LocalDate.class, LocalDate::parse);
converters.put(LocalDateTime.class, LocalDateTime::parse);
converters.put(LocalTime.class, LocalTime::parse);
converters.put(MonthDay.class, MonthDay::parse);
converters.put(OffsetDateTime.class, OffsetDateTime::parse);
converters.put(OffsetTime.class, OffsetTime::parse);
converters.put(Period.class, Period::parse);
converters.put(Year.class, Year::parse);
converters.put(YearMonth.class, YearMonth::parse);
converters.put(ZonedDateTime.class, ZonedDateTime::parse);
converters.put(ZoneId.class, ZoneId::of);
converters.put(ZoneOffset.class, ZoneOffset::of);
CONVERTERS = Collections.unmodifiableMap(converters);
}
@Override
public boolean canConvert(Class targetType) {
return CONVERTERS.containsKey(targetType);
}
@Override
public Object convert(String source, Class targetType) throws Exception {
return CONVERTERS.get(targetType).apply(source);
}
}
private static class StringToCommonJavaTypesConverter implements StringToObjectConverter {
private static final Map, Function> CONVERTERS;
static {
Map, Function> converters = new HashMap<>();
// java.lang
converters.put(Class.class, StringToCommonJavaTypesConverter::toClass);
// java.io and java.nio
converters.put(File.class, File::new);
converters.put(Charset.class, Charset::forName);
converters.put(Path.class, Paths::get);
// java.net
converters.put(URI.class, URI::create);
converters.put(URL.class, StringToCommonJavaTypesConverter::toURL);
// java.math
converters.put(BigDecimal.class, BigDecimal::new);
converters.put(BigInteger.class, BigInteger::new);
// java.util
converters.put(Currency.class, Currency::getInstance);
converters.put(Locale.class, Locale::new);
converters.put(UUID.class, UUID::fromString);
CONVERTERS = Collections.unmodifiableMap(converters);
}
@Override
public boolean canConvert(Class targetType) {
return CONVERTERS.containsKey(targetType);
}
@Override
public Object convert(String source, Class targetType) throws Exception {
return CONVERTERS.get(targetType).apply(source);
}
private static Class toClass(String type) {
//@formatter:off
return ReflectionUtils
.tryToLoadClass(type)
.getOrThrow(cause -> new ArgumentConversionException(
"Failed to convert String \"" + type + "\" to type " + Class.class.getName(), cause));
//@formatter:on
}
private static URL toURL(String url) {
try {
return new URL(url);
}
catch (MalformedURLException ex) {
throw new ArgumentConversionException(
"Failed to convert String \"" + url + "\" to type " + URL.class.getName(), ex);
}
}
}
}