com.github.dactiv.common.bundle.JacksonBundle.java Source code

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Here is the source code for com.github.dactiv.common.bundle.JacksonBundle.java

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/**
 * Copyright (c) 2005-2012 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.github.dactiv.common.bundle;

import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.util.JSONPObject;
import com.fasterxml.jackson.module.jaxb.JaxbAnnotationModule;

/**
 * jackson 
 * 
 * @author calvin
 *
 */
@SuppressWarnings("unchecked")
public class JacksonBundle {

    private static Logger logger = LoggerFactory.getLogger(JacksonBundle.class);

    private ObjectMapper mapper;

    /**
     * 
     * 
     * 
     */
    public JacksonBundle() {
        this(null);
    }

    /**
     * ?Jackson{@link Include}ObjectMapper
     * 
     */
    public JacksonBundle(Include include) {
        mapper = new ObjectMapper();
        if (include != null) {
            mapper.setSerializationInclusion(include);
        }
        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
    }

    /**
     * ??ObjectMapper
     * 
     * <p>
      * :
      * <ul>
      *    <li>
      *         {@link java.util.Collections}  {@link java.util.Map} ? <code>isEmpty()</code>??
      *    </li>
      *    <li>
      *         Java0
      *    </li>
      *    <li>
      *       String? <code>length()</code>??,0
      *    </li>
      * </ul>
      * </p>
      * ?
      * <p>
      * ????{@link JsonSerializer}{@link JsonSerializer#isEmpty(Object)}?
      * ?json???
     * </p>
     * @return {@link JacksonBundle}
     */
    public static JacksonBundle nonEmptyMapper() {

        return new JacksonBundle(Include.NON_EMPTY);
    }

    /**
     * ???jsonObjectMapper
     * 
     * @return {@link JacksonBundle}
     */
    public static JacksonBundle alwaysMapper() {
        return new JacksonBundle(Include.ALWAYS);
    }

    /**
     * ??(null)ObjectMapper
     * 
     * @return {@link JacksonBundle}
     */
    public static JacksonBundle nonNullMapper() {
        return new JacksonBundle(Include.NON_NULL);
    }

    /**
     * ???JsonObjectMapper, ?
     * 
     * @return {@link JacksonBundle}
     */
    public static JacksonBundle nonDefaultMapper() {
        return new JacksonBundle(Include.NON_DEFAULT);
    }

    /** 
     * json?.
      * <pre>
      * jsonnull"null",null. json"[]",?. 
      * ??List/Map,?List&lt;String&gt;???: 
      * List&lt;MyBean&gt; beanList = binder.getMapper().readValue(listString, new TypeReference&lt;List&lt;MyBean&gt;&gt;() {});
      * </pre>
      * 
      * @param json json
      * @param tragetClass ?Class
      * 
      * @return <T>
      */
    public <T> T fromJson(String json, Class<T> tragetClass) {
        if (StringUtils.isEmpty(json)) {
            return null;
        }

        try {
            return mapper.readValue(json, tragetClass);
        } catch (IOException e) {
            logger.warn("parse json string error:" + json, e);
            return null;
        }
    }

    /**
    * ?????CollectionList<Bean>, createCollectionType,?.
    * @see #createCollectionType(Class, Class...)
    */
    public <T> T fromJson(String jsonString, JavaType javaType) {
        if (StringUtils.isEmpty(jsonString)) {
            return null;
        }

        try {
            return (T) mapper.readValue(jsonString, javaType);
        } catch (IOException e) {
            logger.warn("parse json string error:" + jsonString, e);
            return null;
        }
    }

    /**
     * Collection Type:
     * <p>
     * ArrayList<MyBean>, constructCollectionType(ArrayList.class,MyBean.class)
     * HashMap<String,MyBean>, (HashMap.class,String.class, MyBean.class)
     * </p>
     */
    public JavaType createCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {
        return mapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);
    }

    /**
     * JSON??BeanBean?.
     */
    public <T> T update(String jsonString, T object) {
        try {
            return (T) mapper.readerForUpdating(object).readValue(jsonString);
        } catch (JsonProcessingException e) {
            logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
        } catch (IOException e) {
            logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
        }
        return null;
    }

    /**
     * ??json,Null,"null". ??,"[]".
     * 
     * @param target ?json
     */
    public String toJson(Object target) {

        try {
            return mapper.writeValueAsString(target);
        } catch (IOException e) {
            logger.warn("write to json string error:" + target, e);
            return null;
        }
    }

    /** 
     * ?,??Timestamp.
     * 
     * @param pattern ?
     */
    public void setDateFormat(String pattern) {
        if (StringUtils.isNotBlank(pattern)) {
            DateFormat dateFormat = new SimpleDateFormat(pattern);
            mapper.getSerializationConfig().with(dateFormat);
            mapper.getDeserializationConfig().with(dateFormat);
        }
    }

    /**
     * ??JSONP?
     * 
     * @param function jsonp??
     * @param target ?jsonp
     */
    public String toJsonP(String function, Object target) {
        return toJson(new JSONPObject(function, target));
    }

    /**
     * ?EnumtoString??Enum,falseEnumname()?Enum, false.
     */
    public void enableEnumUseToString() {
        mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
        mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
    }

    /**
     * ?JaxbAnnotation,POJOannotation?Jackson?.
     * jaxbannotation,??jackson.
     */
    public void enableJaxbAnnotation() {
        JaxbAnnotationModule module = new JaxbAnnotationModule();
        mapper.registerModule(module);
    }

    /** 
     * ?Mapper??API. 
     * 
     * @return {@link ObjectMapper}
     */
    public ObjectMapper getMapper() {
        return mapper;
    }
}