/*
* 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.env;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.json.JsonParser;
import org.springframework.boot.json.JsonParserFactory;
import org.springframework.core.Ordered;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.core.env.StandardEnvironment;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.context.support.StandardServletEnvironment;
/**
* An {@link EnvironmentPostProcessor} that parses JSON from
* {@code spring.application.json} or equivalently {@code SPRING_APPLICATION_JSON} and
* adds it as a map property source to the {@link Environment}. The new properties are
* added with higher priority than the system properties.
*
* @author Dave Syer
* @author Phillip Webb
* @since 1.3.0
*/
public class SpringApplicationJsonEnvironmentPostProcessor
implements EnvironmentPostProcessor, Ordered {
private static final String SERVLET_ENVIRONMENT_CLASS = "org.springframework.web."
+ "context.support.StandardServletEnvironment";
/**
* The default order for the processor.
*/
public static final int DEFAULT_ORDER = Ordered.HIGHEST_PRECEDENCE + 5;
private static final Log logger = LogFactory
.getLog(SpringApplicationJsonEnvironmentPostProcessor.class);
private int order = DEFAULT_ORDER;
@Override
public int getOrder() {
return this.order;
}
public void setOrder(int order) {
this.order = order;
}
@Override
public void postProcessEnvironment(ConfigurableEnvironment environment,
SpringApplication application) {
String json = environment.resolvePlaceholders(
"${spring.application.json:${SPRING_APPLICATION_JSON:}}");
if (StringUtils.hasText(json)) {
processJson(environment, json);
}
}
private void processJson(ConfigurableEnvironment environment, String json) {
try {
JsonParser parser = JsonParserFactory.getJsonParser();
Map<String, Object> map = parser.parseMap(json);
if (!map.isEmpty()) {
addJsonPropertySource(environment,
new MapPropertySource("spring.application.json", flatten(map)));
}
}
catch (Exception ex) {
logger.warn("Cannot parse JSON for spring.application.json: " + json, ex);
}
}
/**
* Flatten the map keys using period separator.
* @param map The map that should be flattened
* @return the flattened map
*/
private Map<String, Object> flatten(Map<String, Object> map) {
Map<String, Object> result = new LinkedHashMap<>();
flatten(null, result, map);
return result;
}
private void flatten(String prefix, Map<String, Object> result,
Map<String, Object> map) {
prefix = (prefix == null ? "" : prefix + ".");
for (Map.Entry<String, Object> entry : map.entrySet()) {
extract(prefix + entry.getKey(), result, entry.getValue());
}
}
@SuppressWarnings("unchecked")
private void extract(String name, Map<String, Object> result, Object value) {
if (value instanceof Map) {
flatten(name, result, (Map<String, Object>) value);
}
else if (value instanceof Collection) {
int index = 0;
for (Object object : (Collection<Object>) value) {
extract(name + "[" + index + "]", result, object);
index++;
}
}
else {
result.put(name, value);
}
}
private void addJsonPropertySource(ConfigurableEnvironment environment,
PropertySource<?> source) {
MutablePropertySources sources = environment.getPropertySources();
String name = findPropertySource(sources);
if (sources.contains(name)) {
sources.addBefore(name, source);
}
else {
sources.addFirst(source);
}
}
private String findPropertySource(MutablePropertySources sources) {
if (ClassUtils.isPresent(SERVLET_ENVIRONMENT_CLASS, null) && sources
.contains(StandardServletEnvironment.JNDI_PROPERTY_SOURCE_NAME)) {
return StandardServletEnvironment.JNDI_PROPERTY_SOURCE_NAME;
}
return StandardEnvironment.SYSTEM_PROPERTIES_PROPERTY_SOURCE_NAME;
}
}