JacksonUtils

Posted 2020-11-29 f-society

package com.intfish.resourceserver.util;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;
import com.intfish.resourceserver.config.DoubleSerializer;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.List;
import java.util.Map;
import java.util.TimeZone;

public class JacksonUtils {
    private final static ObjectMapper OBJECT_MAPPER;
    static{
        OBJECT_MAPPER = new ObjectMapper();
        // 设置时区
        OBJECT_MAPPER.setTimeZone(TimeZone.getTimeZone("GMT+8"));
        // 设置时间格式
        OBJECT_MAPPER.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

        JavaTimeModule javaTimeModule = new JavaTimeModule();
        /** 序列化配置,针对java8 时间 **/
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        /** 反序列化配置,针对java8 时间 **/
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

        /** 声明自定义模块,配置double类型序列化配置 **/
        SimpleModule module = new SimpleModule("DoubleSerializer", new Version(1, 0, 0, ""));
        // 注意Double和double需要分配配置
        module.addSerializer(Double.class, new DoubleSerializer());
        module.addSerializer(double.class, new DoubleSerializer());

        /** 注册模块 **/
        OBJECT_MAPPER.registerModule(javaTimeModule)
                .registerModule(module)
                .registerModule(new Jdk8Module())
                .registerModule(new ParameterNamesModule());
    }

    private JacksonUtils() {

    }

    public static ObjectMapper getInstance() {
        return OBJECT_MAPPER;
    }

    /**
     * javaBean、列表数组转换为json字符串
     */
    public static String obj2json(Object obj) throws Exception {
        return OBJECT_MAPPER.writeValueAsString(obj);
    }

    /**
     * javaBean、列表数组转换为json字符串,忽略空值
     */
    public static String obj2jsonIgnoreNull(Object obj) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.writeValueAsString(obj);
    }

    /**
     * json 转JavaBean
     */
    public static <T> T json2pojo(String jsonString, Class<T> clazz) throws Exception {
        OBJECT_MAPPER.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
        return OBJECT_MAPPER.readValue(jsonString, clazz);
    }

    /**
     * json字符串转换为map
     */
    public static Map<String, Object> json2map(String jsonString) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        return mapper.readValue(jsonString, new TypeReference<Map<String, Object>>() {});
    }

    /**
     * json字符串转换为map
     */
    public static <T> Map<String, T> json2map(String jsonString, Class<T> clazz) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        Map<String, T> map = mapper.readValue(jsonString, new TypeReference<Map<String, T>>() {});
        return map;
    }

    /**
     * 深度转换json成map
     *
     * @param json
     * @return
     */
    public static Map<String, Object> json2mapDeeply(String json) throws Exception {
        return json2MapRecursion(json, OBJECT_MAPPER);
    }

    /**
     * 把json解析成list，如果list内部的元素存在jsonString，继续解析
     *
     * @param json
     * @param mapper 解析工具
     * @return
     * @throws Exception
     */
    private static List<Object> json2ListRecursion(String json, ObjectMapper mapper) throws Exception {
        if (json == null) {
            return null;
        }

        List<Object> list = mapper.readValue(json, List.class);

        for (Object obj : list) {
            if (obj != null && obj instanceof String) {
                String str = (String) obj;
                if (str.startsWith("[")) {
                    obj = json2ListRecursion(str, mapper);
                } else if (obj.toString().startsWith("{")) {
                    obj = json2MapRecursion(str, mapper);
                }
            }
        }

        return list;
    }
    public static <T> T json2ObjectList(String json,  Class<T> valueType) throws IOException {
        ObjectMapper mapper = JacksonUtils.getInstance();
        return mapper.readValue(json, valueType);
    }

    /**
     * 把json解析成map，如果map内部的value存在jsonString，继续解析
     *
     * @param json
     * @param mapper
     * @return
     * @throws Exception
     */
    private static Map<String, Object> json2MapRecursion(String json, ObjectMapper mapper) throws Exception {
        if (json == null) {
            return null;
        }

        Map<String, Object> map = mapper.readValue(json, Map.class);

        for (Map.Entry<String, Object> entry : map.entrySet()) {
            Object obj = entry.getValue();
            if (obj != null && obj instanceof String) {
                String str = ((String) obj);

                if (str.startsWith("[")) {
                    List<?> list = json2ListRecursion(str, mapper);
                    map.put(entry.getKey(), list);
                } else if (str.startsWith("{")) {
                    Map<String, Object> mapRecursion = json2MapRecursion(str, mapper);
                    map.put(entry.getKey(), mapRecursion);
                }
            }
        }

        return map;
    }

    /**
     * 与javaBean json数组字符串转换为列表
     */
    public static <T> List<T> json2list(String jsonArrayStr) throws Exception {

        List<T> lst = (List<T>) OBJECT_MAPPER.readValue(jsonArrayStr, List.class);
        return lst;
    }

    public static <T> List<T> json2list(String jsonArrayStr, TypeReference<List<T>> typeReference) throws Exception {
        List<T> lst = OBJECT_MAPPER.readValue(jsonArrayStr, typeReference);
        return lst;
    }


    /**
     * 获取泛型的Collection Type
     *
     * @param collectionClass 泛型的Collection
     * @param elementClasses  元素类
     * @return JavaType Java类型
     * @since 1.0
     */
    public static JavaType getCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {
        return OBJECT_MAPPER.getTypeFactory().constructParametricType(collectionClass, elementClasses);
    }


    /**
     * map  转JavaBean
     */
    public static <T> T map2pojo(Map map, Class<T> clazz) {
        return OBJECT_MAPPER.convertValue(map, clazz);
    }

    /**
     * map 转json
     *
     * @param map
     * @return
     */
    public static String mapToJson(Map map) {
        try {
            return OBJECT_MAPPER.writeValueAsString(map);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }
    /**
     * map 转json
     *
     * @param object
     * @return
     */
    public static String objectToJson(Object object) {
        try {
            return OBJECT_MAPPER.writeValueAsString(object);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * map  转JavaBean
     */
    public static <T> T obj2pojo(Object obj, Class<T> clazz) {
        return OBJECT_MAPPER.convertValue(obj, clazz);
    }


}

DoubleSerializer.java

package com.intfish.resourceserver.config;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;
import java.math.BigDecimal;

public class DoubleSerializer extends JsonSerializer<Double> {
    @Override
    public void serialize(Double value, JsonGenerator gen, SerializerProvider serializers)
            throws IOException {
        BigDecimal d = new BigDecimal(value.toString());
        gen.writeNumber(d.stripTrailingZeros().toPlainString());
    }

    @Override
    public Class<Double> handledType() {
        return Double.class;
    }
}