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;
    
    @BeforeAll
    public 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);
        }
    }
    
    @Test
    public void propsTest()
        throws IOException
    {
        String propsJson = JsonBeanUtils.beanToJson(properties);
        log.info("propsJson : {} ", propsJson);
        log.info("properties: {} ", JsonBeanUtils.jsonToBean(propsJson, Properties.class));
    }
    
    @Test
    public 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()));
    }
    
    @Test
    public 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
     */
    @Test
    public 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
     */
    @Test
    public 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;
    
    @BeforeAll
    public 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);
        }
    }
    
    @Test
    public void propsTest()
        throws IOException
    {
        String propsJson = JsonBeanUtils.beanToJson(properties);
        log.info("propsJson : {} ", propsJson);
        log.info("properties: {} ", JsonBeanUtils.jsonToBean(propsJson, Properties.class));
    }
    
    @Test
    public 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()));
    }
    
    @Test
    public 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
     */
    @Test
    public 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
     */
    @Test
    public 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>

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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-