org.springframework.boot.bind.RelaxedNames Maven / Gradle / Ivy
/*
* Copyright 2012-2017 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.boot.bind;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.springframework.util.StringUtils;
/**
* Generates relaxed name variations from a given source.
*
* @author Phillip Webb
* @author Dave Syer
* @see RelaxedDataBinder
* @see RelaxedPropertyResolver
*/
public final class RelaxedNames implements Iterable {
private static final Pattern CAMEL_CASE_PATTERN = Pattern.compile("([^A-Z-])([A-Z])");
private static final Pattern SEPARATED_TO_CAMEL_CASE_PATTERN = Pattern
.compile("[_\\-.]");
private final String name;
private final Set values = new LinkedHashSet();
/**
* Create a new {@link RelaxedNames} instance.
* @param name the source name. For the maximum number of variations specify the name
* using dashed notation (e.g. {@literal my-property-name}
*/
public RelaxedNames(String name) {
this.name = (name == null ? "" : name);
initialize(RelaxedNames.this.name, this.values);
}
@Override
public Iterator iterator() {
return this.values.iterator();
}
private void initialize(String name, Set values) {
if (values.contains(name)) {
return;
}
for (Variation variation : Variation.values()) {
for (Manipulation manipulation : Manipulation.values()) {
String result = name;
result = manipulation.apply(result);
result = variation.apply(result);
values.add(result);
initialize(result, values);
}
}
}
/**
* Name variations.
*/
enum Variation {
NONE {
@Override
public String apply(String value) {
return value;
}
},
LOWERCASE {
@Override
public String apply(String value) {
return value.isEmpty() ? value : value.toLowerCase();
}
},
UPPERCASE {
@Override
public String apply(String value) {
return value.isEmpty() ? value : value.toUpperCase();
}
};
public abstract String apply(String value);
}
/**
* Name manipulations.
*/
enum Manipulation {
NONE {
@Override
public String apply(String value) {
return value;
}
},
HYPHEN_TO_UNDERSCORE {
@Override
public String apply(String value) {
return value.indexOf('-') != -1 ? value.replace('-', '_') : value;
}
},
UNDERSCORE_TO_PERIOD {
@Override
public String apply(String value) {
return value.indexOf('_') != -1 ? value.replace('_', '.') : value;
}
},
PERIOD_TO_UNDERSCORE {
@Override
public String apply(String value) {
return value.indexOf('.') != -1 ? value.replace('.', '_') : value;
}
},
CAMELCASE_TO_UNDERSCORE {
@Override
public String apply(String value) {
if (value.isEmpty()) {
return value;
}
Matcher matcher = CAMEL_CASE_PATTERN.matcher(value);
if (!matcher.find()) {
return value;
}
matcher = matcher.reset();
StringBuffer result = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(result, matcher.group(1) + '_'
+ StringUtils.uncapitalize(matcher.group(2)));
}
matcher.appendTail(result);
return result.toString();
}
},
CAMELCASE_TO_HYPHEN {
@Override
public String apply(String value) {
if (value.isEmpty()) {
return value;
}
Matcher matcher = CAMEL_CASE_PATTERN.matcher(value);
if (!matcher.find()) {
return value;
}
matcher = matcher.reset();
StringBuffer result = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(result, matcher.group(1) + '-'
+ StringUtils.uncapitalize(matcher.group(2)));
}
matcher.appendTail(result);
return result.toString();
}
},
SEPARATED_TO_CAMELCASE {
@Override
public String apply(String value) {
return separatedToCamelCase(value, false);
}
},
CASE_INSENSITIVE_SEPARATED_TO_CAMELCASE {
@Override
public String apply(String value) {
return separatedToCamelCase(value, true);
}
};
private static final char[] SUFFIXES = new char[] { '_', '-', '.' };
public abstract String apply(String value);
private static String separatedToCamelCase(String value,
boolean caseInsensitive) {
if (value.isEmpty()) {
return value;
}
StringBuilder builder = new StringBuilder();
for (String field : SEPARATED_TO_CAMEL_CASE_PATTERN.split(value)) {
field = (caseInsensitive ? field.toLowerCase() : field);
builder.append(
builder.length() == 0 ? field : StringUtils.capitalize(field));
}
char lastChar = value.charAt(value.length() - 1);
for (char suffix : SUFFIXES) {
if (lastChar == suffix) {
builder.append(suffix);
break;
}
}
return builder.toString();
}
}
/**
* Return a {@link RelaxedNames} for the given source camelCase source name.
* @param name the source name in camelCase
* @return the relaxed names
*/
public static RelaxedNames forCamelCase(String name) {
StringBuilder result = new StringBuilder();
for (char c : name.toCharArray()) {
result.append(Character.isUpperCase(c) && result.length() > 0
&& result.charAt(result.length() - 1) != '-'
? "-" + Character.toLowerCase(c) : c);
}
return new RelaxedNames(result.toString());
}
}