/*
* 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.actuate.endpoint.mvc;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.regex.Pattern;
/**
* Utility class that can be used to filter source data using a name regular expression.
* Detects if the name is classic "single value" key or a regular expression. Subclasses
* must provide implementations of {@link #getValue(Object, String)} and
* {@link #getNames(Object, NameCallback)}.
*
* @param <T> the source data type
* @author Phillip Webb
* @author Sergei Egorov
* @author Andy Wilkinson
* @since 1.3.0
*/
abstract class NamePatternFilter<T> {
private static final String[] REGEX_PARTS = { "*", "$", "^", "+", "[" };
private final T source;
NamePatternFilter(T source) {
this.source = source;
}
public Map<String, Object> getResults(String name) {
if (!isRegex(name)) {
Object value = getValue(this.source, name);
Map<String, Object> result = new HashMap<>();
result.put(name, value);
return result;
}
Pattern pattern = Pattern.compile(name);
ResultCollectingNameCallback resultCollector = new ResultCollectingNameCallback(
pattern);
getNames(this.source, resultCollector);
return resultCollector.getResults();
}
private boolean isRegex(String name) {
for (String part : REGEX_PARTS) {
if (name.contains(part)) {
return true;
}
}
return false;
}
protected abstract void getNames(T source, NameCallback callback);
protected abstract Object getValue(T source, String name);
protected abstract Object getOptionalValue(T source, String name);
/**
* Callback used to add a name.
*/
interface NameCallback {
void addName(String name);
}
/**
* {@link NameCallback} implementation to collect results.
*/
private class ResultCollectingNameCallback implements NameCallback {
private final Pattern pattern;
private final Map<String, Object> results = new LinkedHashMap<>();
ResultCollectingNameCallback(Pattern pattern) {
this.pattern = pattern;
}
@Override
public void addName(String name) {
if (this.pattern.matcher(name).matches()) {
Object value = getOptionalValue(NamePatternFilter.this.source, name);
if (value != null) {
this.results.put(name, value);
}
}
}
public Map<String, Object> getResults() {
return this.results;
}
}
}