com.cnksi.core.tools.mapper.JsonMapper.java Source code

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Here is the source code for com.cnksi.core.tools.mapper.JsonMapper.java

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/**
 * Copyright (c) 2005-2012 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */

package com.cnksi.core.tools.mapper;

import java.io.IOException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.cnksi.core.tools.utils.JStringUtils;
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.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.util.JSONPObject;
import com.fasterxml.jackson.module.jaxb.JaxbAnnotationModule;

/**
 * ??JacksonJSON String<->Java ObjectMapper.
 * 
 * ???, ??builder.
 * 
 * @author calvin
 */
@SuppressWarnings("all")
public class JsonMapper {

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

    private ObjectMapper mapper;

    public JsonMapper() {

        this(null);
    }

    public JsonMapper(Include include) {

        mapper = new ObjectMapper();
        //?
        if (include != null) {
            mapper.setSerializationInclusion(include);
        }
        //JSONJava
        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
    }

    /**
     * ??Null?Empty(List.isEmpty)JsonMapper,?.
     */
    public static JsonMapper nonEmptyMapper() {

        return new JsonMapper(Include.NON_EMPTY);
    }

    /**
     * ???JsonMapper, ??
     */
    public static JsonMapper nonDefaultMapper() {

        return new JsonMapper(Include.NON_DEFAULT);
    }

    /**
     * Object?POJO?Collection
     * Null, "null".
     * ??, "[]".
     */
    public String toJson(Object object) {

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

    /**
     * ???POJO?CollectionList<String>.
     * 
     * JSONNull"null", Null.
     * JSON"[]", ?.
     * 
     * ?????CollectionList<MyBean>, fromJson(String,JavaType)
     * @see #fromJson(String, JavaType)
     */
    public <T> T fromJson(String jsonString, Class<T> clazz) {

        if (JStringUtils.isEmpty(jsonString)) {
            return null;
        }

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

    /**
     * ?????CollectionList<Bean>, createCollectionType,?.
     * @see #createCollectionType(Class, Class...)
     */
    public <T> T fromJson(String jsonString, JavaType javaType) {

        if (JStringUtils.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:
     * ArrayList<MyBean>, constructCollectionType(ArrayList.class,MyBean.class)
     * HashMap<String,MyBean>, (HashMap.class,String.class, MyBean.class)
     */
    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;
    }

    /**
     * JSONP?.
     */
    public String toJsonP(String functionName, Object object) {

        return toJson(new JSONPObject(functionName, object));
    }

    /**
     * ?EnumtoStringEnum,
     * FalseEnumname()Enum, ?False.
     * ??Mapper, ?.
     */
    public void enableEnumUseToString() {

        mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
        mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
    }

    /**
     * ?JaxbAnnotationPOJOannotation?Jackson?
     * jaxbannotation??jackson
     */
    public void enableJaxbAnnotation() {

        JaxbAnnotationModule module = new JaxbAnnotationModule();
        mapper.registerModule(module);
    }

    /**
     * ?Mapper??API.
     */
    public ObjectMapper getMapper() {

        return mapper;
    }
}