/*
* Copyright 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.integration.json;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
/**
* Extremely simple JSON serializer. Only handles top level
* properties accessed by getters.
*
* @author Gary Russell
* @since 5.0
*
*/
public final class SimpleJsonSerializer {
private static final Log logger = LogFactory.getLog(SimpleJsonSerializer.class);
private SimpleJsonSerializer() {
super();
}
/**
* Convert the bean to JSON with the provided properties.
* @param bean the object to serialize.
* @param propertiesToExclude the property names to ignore.
* @return the JSON.
*/
public static String toJson(Object bean, String... propertiesToExclude) {
PropertyDescriptor[] propertyDescriptors = BeanUtils.getPropertyDescriptors(bean.getClass());
Set<String> excluded = new HashSet<>(Arrays.asList(propertiesToExclude));
excluded.add("class");
final StringBuilder stringBuilder = new StringBuilder("{");
final Object[] emptyArgs = new Object[0];
for (PropertyDescriptor descriptor : propertyDescriptors) {
String propertyName = descriptor.getName();
Method readMethod = descriptor.getReadMethod();
if (!excluded.contains(propertyName) && readMethod != null) {
stringBuilder.append(toElement(propertyName)).append(":");
Object result;
try {
result = readMethod.invoke(bean, emptyArgs);
}
catch (InvocationTargetException | IllegalAccessException | IllegalArgumentException e) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to serialize property " + propertyName, e);
}
result = e.getMessage();
}
stringBuilder.append(toElement(result)).append(",");
}
}
stringBuilder.setLength(stringBuilder.length() - 1);
stringBuilder.append("}");
if (stringBuilder.length() == 1) {
return null;
}
else {
return stringBuilder.toString();
}
}
private static String toElement(Object result) {
if (result instanceof Number || result instanceof Boolean) {
return result.toString();
}
else {
return "\"" + result.toString() + "\"";
}
}
}