org.springframework.integration.json.SimpleJsonSerializer.java Source code

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Here is the source code for org.springframework.integration.json.SimpleJsonSerializer.java

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/*
 * 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() + "\"";
        }
    }

}