/*
* Copyright 2014-2017 the original author or authors.
*
* 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 org.springframework.data.geo.format;
import java.text.ParseException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.Metric;
import org.springframework.data.geo.Metrics;
import org.springframework.format.Formatter;
import org.springframework.util.StringUtils;
/**
* Converter to create {@link Distance} instances from {@link String} representations. The supported format is a decimal
* followed by whitespace and a metric abbreviation. We currently support the following abbreviations:
* {@value #SUPPORTED_METRICS}.
*
* @author Oliver Gierke
* @author Christoph Strobl
*/
public enum DistanceFormatter implements Converter<String, Distance>, Formatter<Distance> {
INSTANCE;
private static final Map<String, Metric> SUPPORTED_METRICS;
private static final String INVALID_DISTANCE = "Expected double amount optionally followed by a metrics abbreviation (%s) but got '%s'!";
static {
Map<String, Metric> metrics = new LinkedHashMap<>();
for (Metric metric : Metrics.values()) {
metrics.put(metric.getAbbreviation(), metric);
metrics.put(metric.toString().toLowerCase(Locale.US), metric);
}
SUPPORTED_METRICS = Collections.unmodifiableMap(metrics);
}
/*
* (non-Javadoc)
* @see org.springframework.core.convert.converter.Converter#convert(java.lang.Object)
*/
@Override
public final Distance convert(String source) {
return source == null ? null : doConvert(source.trim().toLowerCase(Locale.US));
}
/*
* (non-Javadoc)
* @see org.springframework.format.Printer#print(java.lang.Object, java.util.Locale)
*/
@Override
public String print(Distance distance, Locale locale) {
return distance == null ? null : String.format("%s%s", distance.getValue(), distance.getUnit().toLowerCase(locale));
}
/*
* (non-Javadoc)
* @see org.springframework.format.Parser#parse(java.lang.String, java.util.Locale)
*/
@Override
public Distance parse(String text, Locale locale) throws ParseException {
return !StringUtils.hasText(text) ? null : doConvert(text.trim().toLowerCase(locale));
}
/**
* Converts the given {@link String} source into a distance. Expects the source to reflect the {@link Metric} as held
* in the {@link #SUPPORTED_METRICS} map.
*
* @param source must not be {@literal null}.
* @return
*/
private static Distance doConvert(String source) {
for (Entry<String, Metric> metric : SUPPORTED_METRICS.entrySet()) {
if (source.endsWith(metric.getKey())) {
return fromString(source, metric);
}
}
try {
return new Distance(Double.parseDouble(source));
} catch (NumberFormatException o_O) {
throw new IllegalArgumentException(String.format(INVALID_DISTANCE,
StringUtils.collectionToCommaDelimitedString(SUPPORTED_METRICS.keySet()), source));
}
}
/**
* Creates a {@link Distance} from the given source String and the {@link Metric} detected.
*
* @param source the raw source {@link String}, must not be {@literal null} or empty.
* @param metric the {@link Metric} detected keyed by the keyword it was detected for, must not be {@literal null}.
* @return
*/
private static Distance fromString(String source, Entry<String, Metric> metric) {
String amountString = source.substring(0, source.indexOf(metric.getKey()));
try {
return new Distance(Double.parseDouble(amountString), metric.getValue());
} catch (NumberFormatException o_O) {
throw new IllegalArgumentException(String.format(INVALID_DISTANCE,
StringUtils.collectionToCommaDelimitedString(SUPPORTED_METRICS.keySet()), source));
}
}
}