基于jackson封装的json字符串与javaBean对象转换工具

一、概述

带有API接口交互的web项目开发过程中，json字符串与javaBean对象之间的相互转换是比较常见的需求，基于jackson ObjectMapper 实现的工具类较好的满足了此需求。

二、编码实现

1. pom文件引入组件

<dependency><groupId>org.springframework</groupId><artifactId>spring-webflux</artifactId><version>5.2.3.RELEASE</version></dependency><dependency><groupId>io.projectreactor.netty</groupId><artifactId>reactor-netty</artifactId><version>0.9.4.RELEASE</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.12.1</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.10.2</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.10</version></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.5</version></dependency><dependency><groupId>org.junit.jupiter</groupId><artifactId>junit-jupiter-api</artifactId><version>5.5.2</version><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version><scope>provided</scope></dependency>

2. 核心代码

JsonBeanUtils

import java.io.IOException;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;/*** JsonBean转换工具* * @author 00fly**/
public class JsonBeanUtils
{private static ObjectMapper objectMapper = new ObjectMapper();/*** bean转json字符串* * @param bean* @return* @throws IOException*/public static String beanToJson(Object bean)throws IOException{String jsonText = objectMapper.writeValueAsString(bean);return objectMapper.readTree(jsonText).toPrettyString();}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, Class<T> clazz)throws IOException{return objectMapper.readValue(jsonText, clazz);}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, JavaType javaType)throws IOException{return objectMapper.readValue(jsonText, javaType);}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, TypeReference<T> typeRef)throws IOException{return objectMapper.readValue(jsonText, typeRef);}
}

三、功能测试

1. 测试文件

jdbc.properties

druid.username=sa
druid.password=
druid.url=jdbc:h2:mem:hello;database_to_upper=false
druid.driverClassName=org.h2.Driver

data.json

{"code": 200,"message": "success","traceId": "fcd55497-864a-4d74-9db0-69a04655184f","data": {"list": [{"articleId": 135418954,"title": "java解析json复杂数据的两种思路","description": "萌新小明最近新开了CSDN博客，蠢蠢欲动，迫不及待的发表了几篇工作中积累下来的解决问题的涂鸦之作，看着访问量慢慢涨起来，心中暗暗窃喜。现在小明想每天23点记录一下每篇文章的访问量。。。","url": "https://blog.csdn.net/qq_16127313/article/details/135418954","type": 1,"top": false,"forcePlan": false,"viewCount": 828,"commentCount": 0,"editUrl": "https://editor.csdn.net/md?articleId=135418954","postTime": "2024-01-06 14:11:40","diggCount": 16,"formatTime": "前天 14:11","picList": ["https://img-blog.csdnimg.cn/direct/a409a0f4555c459fa05c00fd9ee0ea8c.png"],"collectCount": 19},{"articleId": 135244727,"title": "java lambda表达式训练题一","description": "Lambda 表达式，也可称为闭包，它是推动 Java 8 发布的最重要新特性。Lambda 允许把函数作为一个方法的参数（函数作为参数传递进方法中）。使用 Lambda 表达式可以使代码变的更加简洁紧凑。","url": "https://blog.csdn.net/qq_16127313/article/details/135244727","type": 1,"top": false,"forcePlan": false,"viewCount": 1238,"commentCount": 0,"editUrl": "https://editor.csdn.net/md?articleId=135244727","postTime": "2023-12-27 18:07:30","diggCount": 7,"formatTime": "2023.12.27","picList": ["https://img-blog.csdnimg.cn/direct/d59c68b950754e879914b5319cd1b53f.png"],"collectCount": 8},{"articleId": 135173565,"title": "二维码初体验 com.google.zxing 实现续 - web api封装","description": "在 二维码初体验 com.google.zxing 实现 我们实现了二维码的生成，但是大部分情况下，二维码的相关功能是作为API接口来提供服务的。我们下面便演示在springboot、Knife4j下封装api接口来实现二维码生成功能。如何使用下面的备份文件恢复成原始的项目代码，请移步查阅：神奇代码恢复工具-over-","url": "https://blog.csdn.net/qq_16127313/article/details/135173565","type": 1,"top": false,"forcePlan": false,"viewCount": 1904,"commentCount": 0,"editUrl": "https://editor.csdn.net/md?articleId=135173565","postTime": "2023-12-23 20:17:11","diggCount": 23,"formatTime": "2023.12.23","picList": ["https://img-blog.csdnimg.cn/direct/f0c994ca789a495a8c8c03d86d626f24.jpeg"],"collectCount": 23},{"articleId": 135167613,"title": "二维码初体验 com.google.zxing 实现","description": "Java 操作二维码的开源项目很多，如 SwetakeQRCode、BarCode4j、Zxing 等，这边以Zxing 为例进行介绍。选择需要生成QR原始文件，支持 “清除空白行及空格” 以减少二维码图片大小。支持输入文本内容，直接生成二维码代码结构QrCodeUI: 完整版本代码SimpleQrCodeUI：简化版本代码如何使用下面的备份文件恢复成原始的项目代码，请移步查阅：神奇代码恢复工具-over-","url": "https://blog.csdn.net/qq_16127313/article/details/135167613","type": 1,"top": false,"forcePlan": false,"viewCount": 1286,"commentCount": 0,"editUrl": "https://editor.csdn.net/md?articleId=135167613","postTime": "2023-12-23 13:52:23","diggCount": 6,"formatTime": "2023.12.23","picList": ["https://img-blog.csdnimg.cn/direct/d3eeac85857543869dce8967c570bdc4.jpeg"],"collectCount": 11},{"articleId": 135135799,"title": "【随笔】MD5加密字符串、文件apache、springframework实现","description": "【代码】【随笔】MD5加密字符串、文件commons-codec、springframework实现。","url": "https://blog.csdn.net/qq_16127313/article/details/135135799","type": 1,"top": false,"forcePlan": false,"viewCount": 1721,"commentCount": 0,"editUrl": "https://editor.csdn.net/md?articleId=135135799","postTime": "2023-12-21 17:29:54","diggCount": 9,"formatTime": "2023.12.21","picList": ["https://img-blog.csdnimg.cn/direct/dc26b7f1c731494f80c8c3b3badfa95d.jpeg"],"collectCount": 9}],"total": 72}
}

2. 测试代码

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Properties;import org.apache.commons.io.IOUtils;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.type.TypeFactory;import lombok.Data;
import lombok.extern.slf4j.Slf4j;/*** JsonBeanUtils测试*/
@Slf4j
public class JsonBeanUtilsTest
{static String jsonText;static Properties properties;static WebClient webClient;static String url;@BeforeAllpublic static void init(){try{properties = PropertiesLoaderUtils.loadProperties(new ClassPathResource("jdbc.properties"));jsonText = IOUtils.toString(new ClassPathResource("data.json").getURL(), StandardCharsets.UTF_8);webClient = WebClient.builder().codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)).build();url = "https://blog.csdn.net/community/home-api/v1/get-business-list?page=1&size=5&businessType=blog&username=qq_16127313";}catch (IOException e){log.error(e.getMessage(), e);}}@Testpublic void propsTest()throws IOException{String propsJson = JsonBeanUtils.beanToJson(properties);log.info("propsJson : {} ", propsJson);log.info("properties: {} ", JsonBeanUtils.jsonToBean(propsJson, Properties.class));}@Testpublic void beanToJson001()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);log.info("blogData: {} ", blogData);log.info("blogData: {} ", JsonBeanUtils.beanToJson(blogData));log.info("blogData.data: {} ", JsonBeanUtils.beanToJson(blogData.getData()));log.info("blogData.data.list: {} ", JsonBeanUtils.beanToJson(blogData.getData().getList()));}@Testpublic void beanToJson002()throws IOException{String resp = webClient.get().uri(url).acceptCharset(StandardCharsets.UTF_8).accept(MediaType.APPLICATION_JSON).retrieve().bodyToMono(String.class).block();BlogData blogData = JsonBeanUtils.jsonToBean(resp, BlogData.class);String jsonText = JsonBeanUtils.beanToJson(blogData);log.info("blogData: {} ", blogData);log.info("jsonText: {} ", jsonText);}/*** 测试 JsonBeanUtils.jsonToBean(String jsonText, JavaType javaType)* * @throws IOException*/@Testpublic void jsonToBean001()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);String jsonStr = JsonBeanUtils.beanToJson(blogData.getData().getList());// List<SubList>JavaType javaType = TypeFactory.defaultInstance().constructParametricType(List.class, SubList.class);List<SubList> dataEntitys = JsonBeanUtils.jsonToBean(jsonStr, javaType);log.info("dataEntitys: {} ", dataEntitys);}/*** 测试 JsonBeanUtils.jsonToBean(String jsonText, TypeReference<T> typeRef)* * @throws IOException*/@Testpublic void jsonToBean002()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);String jsonStr = JsonBeanUtils.beanToJson(blogData.getData().getList());// List<SubList>TypeReference<List<SubList>> typeRef = new TypeReference<List<SubList>>(){};List<SubList> dataEntitys = JsonBeanUtils.jsonToBean(jsonStr, typeRef);log.info("dataEntitys: {} ", dataEntitys);}
}@Data
class BlogData
{private Integer code;private String message;private String traceId;private Record data;
}@Data
class Record
{private List<SubList> list;private Long total;
}@Data
class SubList
{String articleId;String title;String description;String url;Integer type;String top;String forcePlan;Long viewCount;Long commentCount;String editUrl;String postTime;Long diggCount;String formatTime;Object picList;Long collectCount;
}

四，完整代码

如何使用下面的备份文件恢复成原始的项目代码，请移步查阅：神奇代码恢复工具

//goto pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.fly</groupId><artifactId>base</artifactId><version>0.0.1</version><name>base</name><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><java.version>1.8</java.version><skipTests>true</skipTests></properties><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-webflux</artifactId><version>5.2.3.RELEASE</version></dependency><dependency><groupId>io.projectreactor.netty</groupId><artifactId>reactor-netty</artifactId><version>0.9.4.RELEASE</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.12.1</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.10.2</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.10</version></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.5</version></dependency><dependency><groupId>org.junit.jupiter</groupId><artifactId>junit-jupiter-api</artifactId><version>5.5.2</version><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version><scope>provided</scope></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.10.1</version><configuration><source>1.8</source><target>1.8</target><encoding>UTF-8</encoding></configuration></plugin></plugins></build>
</project>
//goto src\main\java\com\fly\core\utils\JsonBeanUtils.java
package com.fly.core.utils;import java.io.IOException;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;/*** JsonBean转换工具* * @author 00fly**/
public class JsonBeanUtils
{private static ObjectMapper objectMapper = new ObjectMapper();/*** bean转json字符串* * @param bean* @return* @throws IOException*/public static String beanToJson(Object bean)throws IOException{String jsonText = objectMapper.writeValueAsString(bean);return objectMapper.readTree(jsonText).toPrettyString();}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, Class<T> clazz)throws IOException{return objectMapper.readValue(jsonText, clazz);}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, JavaType javaType)throws IOException{return objectMapper.readValue(jsonText, javaType);}/*** json字符串转bean* * @param jsonText* @return* @throws IOException*/public static <T> T jsonToBean(String jsonText, TypeReference<T> typeRef)throws IOException{return objectMapper.readValue(jsonText, typeRef);}
}
//goto src\main\resources\log4j2.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration status="off" monitorInterval="0"><appenders><console name="Console" target="system_out"><patternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" /></console></appenders><loggers><root level="INFO"><appender-ref ref="Console" /></root></loggers>
</configuration>
//goto src\test\java\com\fly\core\utils\JsonBeanUtilsTest.java
package com.fly.core.utils;import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Properties;import org.apache.commons.io.IOUtils;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.type.TypeFactory;import lombok.Data;
import lombok.extern.slf4j.Slf4j;/*** JsonBeanUtils测试*/
@Slf4j
public class JsonBeanUtilsTest
{static String jsonText;static Properties properties;static WebClient webClient;static String url;@BeforeAllpublic static void init(){try{properties = PropertiesLoaderUtils.loadProperties(new ClassPathResource("jdbc.properties"));jsonText = IOUtils.toString(new ClassPathResource("data.json").getURL(), StandardCharsets.UTF_8);webClient = WebClient.builder().codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)).build();url = "https://blog.csdn.net/community/home-api/v1/get-business-list?page=1&size=5&businessType=blog&username=qq_16127313";}catch (IOException e){log.error(e.getMessage(), e);}}@Testpublic void propsTest()throws IOException{String propsJson = JsonBeanUtils.beanToJson(properties);log.info("propsJson : {} ", propsJson);log.info("properties: {} ", JsonBeanUtils.jsonToBean(propsJson, Properties.class));}@Testpublic void beanToJson001()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);log.info("blogData: {} ", blogData);log.info("blogData: {} ", JsonBeanUtils.beanToJson(blogData));log.info("blogData.data: {} ", JsonBeanUtils.beanToJson(blogData.getData()));log.info("blogData.data.list: {} ", JsonBeanUtils.beanToJson(blogData.getData().getList()));}@Testpublic void beanToJson002()throws IOException{String resp = webClient.get().uri(url).acceptCharset(StandardCharsets.UTF_8).accept(MediaType.APPLICATION_JSON).retrieve().bodyToMono(String.class).block();BlogData blogData = JsonBeanUtils.jsonToBean(resp, BlogData.class);String jsonText = JsonBeanUtils.beanToJson(blogData);log.info("blogData: {} ", blogData);log.info("jsonText: {} ", jsonText);}/*** 测试 JsonBeanUtils.jsonToBean(String jsonText, JavaType javaType)* * @throws IOException*/@Testpublic void jsonToBean001()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);String jsonStr = JsonBeanUtils.beanToJson(blogData.getData().getList());// List<SubList>JavaType javaType = TypeFactory.defaultInstance().constructParametricType(List.class, SubList.class);List<SubList> dataEntitys = JsonBeanUtils.jsonToBean(jsonStr, javaType);log.info("dataEntitys: {} ", dataEntitys);}/*** 测试 JsonBeanUtils.jsonToBean(String jsonText, TypeReference<T> typeRef)* * @throws IOException*/@Testpublic void jsonToBean002()throws IOException{BlogData blogData = JsonBeanUtils.jsonToBean(jsonText, BlogData.class);String jsonStr = JsonBeanUtils.beanToJson(blogData.getData().getList());// List<SubList>TypeReference<List<SubList>> typeRef = new TypeReference<List<SubList>>(){};List<SubList> dataEntitys = JsonBeanUtils.jsonToBean(jsonStr, typeRef);log.info("dataEntitys: {} ", dataEntitys);}
}@Data
class BlogData
{private Integer code;private String message;private String traceId;private Record data;
}@Data
class Record
{private List<SubList> list;private Long total;
}@Data
class SubList
{String articleId;String title;String description;String url;Integer type;String top;String forcePlan;Long viewCount;Long commentCount;String editUrl;String postTime;Long diggCount;String formatTime;Object picList;Long collectCount;
}
//goto src\test\resources\jdbc.properties
druid.username=sa
druid.password=
druid.url=jdbc:h2:mem:hello;database_to_upper=false
druid.driverClassName=org.h2.Driver
//goto src\test\resources\log4j2.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration status="off" monitorInterval="0"><appenders><console name="Console" target="system_out"><patternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" /></console></appenders><loggers><root level="INFO"><appender-ref ref="Console" /></root></loggers>
</configuration>

---

有任何问题和建议，都可以向我提问讨论,大家一起进步，谢谢!

-over-