JSON 解析工具的封装(Java)

Z时代
2024-01-10
分类：综合

java

JSON 自封装工具类

JSON 解析工具的封装（Java）

　　一直想有一个属于自己的JSON工具，今天终于弄好了.....

　　　1.添加pom依赖包

<!--json解析-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.7.4</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.7.4</version>
        </dependency>

　　2.JSONUtils.java

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.*;
/**
 * Created by 杨永生 on 2017/4/26.
 */
public class JSONUtils {
    private final static ObjectMapper objectMapper = new ObjectMapper();
    static {
        //去掉默认的时间戳格式
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        //设置为中国上海时区
        objectMapper.setTimeZone(TimeZone.getTimeZone("GMT+8"));
        objectMapper.configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false);
        //空值不序列化
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        //反序列化时，属性不存在的兼容处理
        objectMapper.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        //序列化时，日期的统一格式
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
        objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        //单引号处理
        objectMapper.configure(com.fasterxml.jackson.core.JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
    }
    private JSONUtils() {
    }
    public static ObjectMapper getInstance() {
        return objectMapper;
    }
    /**
     * javaBean,list,array convert to json string
     */
    public static String obj2json(Object obj){
        try {
            return objectMapper.writeValueAsString(obj);
        }catch (Exception e){
            e.printStackTrace();
        }
        return "";
    }
    public static <T> T obj2obj(Object obj, Class<T> clazz){
        try {
           String str=obj2json(obj);
            return json2pojo(str,clazz);
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
    /**
     * json string convert to javaBean
     */
    public static <T> T json2pojo(String jsonStr, Class<T> clazz) {
        try {
            return objectMapper.readValue(jsonStr, clazz);
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
    /**
     * json string convert to map
     */
    public static <T> Map<String, Object> json2map(String jsonStr)
            throws Exception {
        return objectMapper.readValue(jsonStr, Map.class);
    }
    public static <T> T fromJson(TypeReference<T> tr,byte[] content){
        T t=null;
        try {
            t = objectMapper.readValue(content,0, content.length, tr);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return t;
    }
    /**
     * json string convert to map with javaBean
     */
    public static <T> Map<String, T> json2map(String jsonStr, Class<T> clazz)
            throws Exception {
        Map<String, Map<String, Object>> map = objectMapper.readValue(jsonStr,
                new TypeReference<Map<String, T>>() {
                });
        Map<String, T> result = new HashMap<String, T>();
        for (Map.Entry<String, Map<String, Object>> entry : map.entrySet()) {
            result.put(entry.getKey(), map2pojo(entry.getValue(), clazz));
        }
        return result;
    }
    /**
     * json array string convert to list with javaBean
     */
    public static <T> List<T> json2list(String jsonArrayStr, Class<T> clazz)
            throws Exception {
        List<Map<String, Object>> list = objectMapper.readValue(jsonArrayStr,
                new TypeReference<List<T>>() {
                });
        List<T> result = new ArrayList<T>();
        for (Map<String, Object> map : list) {
            result.add(map2pojo(map, clazz));
        }
        return result;
    }
    /**
     * map convert to javaBean
     */
    public static <T> T map2pojo(Map map, Class<T> clazz) {
        return objectMapper.convertValue(map, clazz);
    }
}