问题背景
因为经常用到fastjson，但fastjson里面有些转换没有，自己写了一个工具类，方便快捷进行转换
注意事项：
Fastjson转换
1 FastjsonUtils工具转换类
package com.yg.fastjson.utils;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.serializer.SimpleDateFormatSerializer;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import java.util.*;
* @Author suolong
* @Date 2022/3/19 11:24
* @Version 1.5
@Slf4j
public final class FastjsonUtils {
//fastjson格式转换器
private static SerializeConfig config;
static {
config = new SerializeConfig();
config.put(Date.class, new SimpleDateFormatSerializer("yyyy-MM-dd HH:mm:ss"));
private static final SerializerFeature[] features = {
// 输出空置字段
SerializerFeature.WriteMapNullValue,
// list字段如果为null，输出为[]，而不是null
SerializerFeature.WriteNullListAsEmpty,
// 数值字段如果为null，输出为0，而不是null
SerializerFeature.WriteNullNumberAsZero,
// Boolean字段如果为null，输出为false，而不是null
SerializerFeature.WriteNullBooleanAsFalse,
// 字符类型字段如果为null，输出为""，而不是null
SerializerFeature.WriteNullStringAsEmpty
* Object TO Json String 字符串输出
public static String toJSONString(Object object) {
try {
return JSON.toJSONString(object, config, features);
} catch (Exception e) {
log.error("JsonUtil | method=toJSON() | 对象转为Json字符串 Error！" + e.getMessage(), e);
return null;
* Object TO Json String Json-lib兼容的日期输出格式
public static String toJSONLib(Object object) {
try {
return JSON.toJSONString(object, config, features);
} catch (Exception e) {
log.error("JsonUtil | method=toJSONLib() | 对象转为Json字符串 Json-lib兼容的日期输出格式 Error！" + e.getMessage(), e);
return null;
* 转换为数组 Object
public static Object[] toArray(String text) {
try {
return toArray(text, null);
} catch (Exception e) {
log.error("JsonUtil | method=toArray() | 将json格式的数据转换为数组 Object Error！" + e.getMessage(), e);
return null;
* 转换为数组 （可指定类型）
public static <T> Object[] toArray(String text, Class<T> clazz) {
try {
return JSON.parseArray(text, clazz).toArray();
} catch (Exception e) {
log.error("JsonUtil | method=toArray() | 将json格式的数据转换为数组 （可指定类型） Error！" + e.getMessage(), e);
return null;
* List转换为JSONArray
public static JSONArray toJSONArray(List<?> list) {
try {
String json = toJSONString(list);
return JSONArray.parseArray(json);
} catch (Exception e) {
log.error("JsonUtil | method=toJSONArray() | 将list格式的数据转换为JSONArray Object Error！" + e.getMessage(), e);
return null;
* 重载类型为String
* Json 转为 Jave Bean, 再使用Bean类型进行强转
public static <T> T toBean(String text, Class<T> clazz) {
try {
return JSON.parseObject(text, clazz);
} catch (Exception e) {
log.error("JsonUtil | method=toBean() | Json 转为 Jave Bean Error！" + e.getMessage(), e);
return null;
* 重载类型为JSONObject
* Json 转为 Jave Bean, 再使用Bean类型进行强转
public static <T> T toBean(JSONObject text, Class<T> clazz) {
try {
String json = toJSONString(text);
return toBean(json, clazz);
} catch (Exception e) {
log.error("JsonUtil | method=toBean() | Json 转为 Jave Bean Error！" + e.getMessage(), e);
return null;
* 重载类型为String
* Json 转为 Map，JSON.parseObject转换的类型为JSONObject，但是JSONObject实现了Map接口
public static Map<?, ?> toMap(String json) {
try {
return JSON.parseObject(json);
} catch (Exception e) {
log.error("JsonUtil | method=toMap() | Json 转为 Map {},{}" + e.getMessage(), e);
return null;
* 重载类型为JSONObject
* Json 转为 Map，JSON.parseObject转换的类型为JSONObject，但是JSONObject实现了Map接口
public static Map<?, ?> toMap(JSONObject json) {
try {
return JSON.parseObject(JSON.toJSONString(json));
} catch (Exception e) {
log.error("JsonUtil | method=toMap() | Json 转为 Map {},{}" + e.getMessage(), e);
return null;
* 重载类型为String
* Json 转为 Map，JSON.parseObject转换的类型为JSONObject，但是JSONObject实现了Map接口
public static HashMap<?, ?> toHashMap(String json) {
try {
Map<?, ?> map = toMap(json);
return new HashMap<>(map);
} catch (Exception e) {
log.error("JsonUtil | method=toMap() | Json 转为 Map {},{}" + e.getMessage(), e);
return null;
* 重载类型为JSONObject
* Json 转为 Map，JSON.parseObject转换的类型为JSONObject，但是JSONObject实现了Map接口
public static HashMap<?, ?> toHashMap(JSONObject json) {
try {
Map<?, ?> map = toMap(json);
return new HashMap<>(map);
} catch (Exception e) {
log.error("JsonUtil | method=toMap() | Json 转为 Map {},{}" + e.getMessage(), e);
return null;
* 重载类型为String
* Json 转 List,Class 集合中泛型的类型，非集合本身，可json-lib兼容的日期格式
public static <T> List<T> toList(String text, Class<T> clazz) {
try {
return JSON.parseArray(text, clazz);
} catch (Exception e) {
log.error("JsonUtil | method=toList() | Json 转为 List {},{}" + e.getMessage(), e);
return null;
* 重载类型为JSONObject
* Json 转 List,Class 集合中泛型的类型，非集合本身，可json-lib兼容的日期格式
public static <T> List<T> toList(JSONArray text, Class<T> clazz) {
try {
String json = toJSONString(text);
return toList(json, clazz);
} catch (Exception e) {
log.error("JsonUtil | method=toList() | Json 转为 List {},{}" + e.getMessage(), e);
return null;
* 重载类型为String
* Json 转 List,Class 集合中泛型的类型，非集合本身，可json-lib兼容的日期格式
public static <T> ArrayList<T> toArrayList(String text, Class<T> clazz) {
try {
List<T> list = toList(text, clazz);
assert list != null;
return new ArrayList<>(list);
} catch (Exception e) {
log.error("JsonUtil | method=toList() | Json 转为 List {},{}" + e.getMessage(), e);
return null;
* 重载类型为JSONObject,clazz为list里面的类型
* Json 转 List,Class 集合中泛型的类型，非集合本身，可json-lib兼容的日期格式
public static <T> ArrayList<T> toArrayList(JSONArray text, Class<T> clazz) {
try {
List<T> list = toList(text, clazz);
assert list != null;
return new ArrayList<>(list);
} catch (Exception e) {
log.error("JsonUtil | method=toList() | Json 转为 List {},{}" + e.getMessage(), e);
return null;
* 重载类型为String
* 从json字符串获取指定key的字符串
public static Object getValueFromJson(final String json, final String key) {
try {
if (StringUtils.isBlank(json) || StringUtils.isBlank(key)) {
return null;
return JSON.parseObject(json).getString(key);
} catch (Exception e) {
log.error("JsonUtil | method=getStringFromJson() | 从json获取指定key的字符串 Error！" + e.getMessage(), e);
return null;
* 重载类型为JSONObject
* 从json字符串获取指定key的字符串
public static Object getValueFromJson(final JSONObject json, final String key) {
try {
String text = toJSONString(json);
return getValueFromJson(text, key);
} catch (Exception e) {
log.error("JsonUtil | method=getStringFromJson() | 从json获取指定key的字符串 Error！" + e.getMessage(), e);
return null;
2 测试main函数
package com.yg.fastjson.service;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.yg.fastjson.response.Response;
import com.yg.fastjson.utils.FastjsonUtils;
import com.yg.fastjson.utils.JsonUtils;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
* @Author suolong
* @Date 2022/3/18 17:55
* @Version 1.0
public class FastjsonTest {
public static void main(String[] args) {
List<HashMap<Integer, Integer>> arrayList = new ArrayList<>();
for (int i = 0; i < 5; i++) {
HashMap<Integer, Integer> hashMap = new HashMap<>();
hashMap.put(i + 11, i + 10);
hashMap.put(i + 21, i + 10);
hashMap.put(i + 31, i + 10);
arrayList.add(hashMap);
//将List转为JSONString
String jsonString = FastjsonUtils.toJSONString(arrayList);
System.out.println(jsonString);
//将List转为JSONArray
JSONArray jsonArray = FastjsonUtils.toJSONArray(arrayList);
System.out.println(jsonArray.toString());
//将JSONArray转为List
List<HashMap> hpList= FastjsonUtils.toList(jsonArray, HashMap.class);
System.out.println(hpList.get(0).getClass());
//将JSONArray转为ArrayList
ArrayList<HashMap> arrayList1 = FastjsonUtils.toArrayList(jsonArray, HashMap.class);
System.out.println(arrayList1.get(0).get(11+""));
//将string转为bean
Response<String> boy = Response.success("you are a cool boy");
String s = JSON.toJSONString(boy);
Response response = FastjsonUtils.toBean(s, Response.class);
System.out.println(response);
3 代码中测试Bean转换的response类
package com.yg.fastjson.response;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletResponse;
import java.io.Serializable;
public class Response<T> implements Serializable {
private static final long serialVersionUID = -1222614520893986846L;
private T data;
* 错误码
private String code;
* 错误信息
private String msg;
public Response() {}
public Response(T data, String code, String msg) {
this.data = data;
this.code = code;
this.msg = msg;
public T getData() {
return data;
public void setData(T data) {
this.data = data;
public String getCode() {
return code;
public void setCode(String code) {
this.code = code;
public String getMsg() {
return msg;
public void setMsg(String msg) {
this.msg = msg;
public static <T> Response<T> success(T data){
return new Response<T>(data, ResponseCode.SUCESS, "ok");
public static <T> Response<T> success(T data, ResultCode resultCode){
return new Response<T>(data, resultCode.getCode(), resultCode.getMsg());
public static <T> Response<T> notFound(){
return new Response<T>(null, ResponseCode.FAIL, "server error");
// public static <T> Response<T> internalError(){
// return new Response<T>(null, ResultCode.CODE_98.getCode(), ResultCode.CODE_98.getMsg());
// }
* 系统异常，为了不影响客户，返回数据未查的
* @param <T>
* @return
public static <T> Response<T> internalError(){
return new Response<T>(null, ResultCode.CODE_02.getCode(), ResultCode.CODE_02.getMsg());
public static <T> Response<T> internalError(String msg){
//setResponseStatus(500);
return new Response<T>(null, ResponseCode.FAIL, msg);
public static <T> Response<T> needLoginError(String msg){
setResponseStatus(500);
return new Response<T>(null, ResponseCode.NEEDLOGIN, msg);
private static void setResponseStatus(int i) {
ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
if (servletRequestAttributes == null) {
//log.warn("failed to set response, because can't get HttpServletResponse");
return;
final HttpServletResponse response = servletRequestAttributes.getResponse();
if (response == null) {
//log.warn("failed to set response, because can't get HttpServletResponse");
return;
response.setStatus(i);
@Override
public String toString() {
return "Response [data:" + data + ", code:" + code + ", message:" + msg + "]";
package com.yg.fastjson.response;
public class ResponseCode {
* 表明该请求被成功地完成，所请求的资源发送到客户端。
public static final String SUCESS = "200";
* 系统执行错误
public static final String FAIL = "500";
* 系统执行错误
public static final String NEEDLOGIN = "401";
package com.yg.fastjson.response;
public enum ResultCode {
//00：成功，01：入参存在非法null，02：数据未查得，98：系统异常
CODE_00("00","成功"),
CODE_01("01","入参存在非法null"),
CODE_02("02","数据未查得"),
CODE_03("03","非规定的调用时间"),
CODE_98("98","系统异常"),
CODE_401("401","未登录");
private String code;
private String msg;
ResultCode(String code, String msg) {
this.code = code;
this.msg = msg;
public String getCode() {
return code;
public String getMsg() {
return msg;
这个工具类挺好用的，有新的转法我会及时更新
作为程序员第 78 篇文章，每次写一句歌词记录一下，看看人生有几首歌的时间，wahahaha ...