SpringBoot整合Jackson的過程詳解
環(huán)境參考
- Jdk: 1.8
- Springboot: 2.7.6
- Jackson: 2.13.4
整合步驟
一、引入 Maven 依賴
<?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.liboshuai</groupId>
<artifactId>springboot-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot-example</name>
<description>springboot-example</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<!--spring boot版本-->
<spring-boot.version>2.7.6</spring-boot.version>
<!--maven-compiler-plugin-->
<maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
</properties>
<dependencies>
<!---################## 主要關注這個 ##################-->
<!--spring boot web依賴-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--spring boot test依賴-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<finalName>${project.artifactId}-${project.version}</finalName>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>application-${profilesActive}.properties</include>
<include>application.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>${spring-boot.version}</version>
<configuration>
<mainClass>com.liboshuai.springbootexample.SpringbootExampleApplication</mainClass>
<layout>ZIP</layout>
</configuration>
<executions>
<execution>
<id>repackage</id>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- 指定jdk版本,和指定編碼 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
因為是Springboot-web項目,所以直接引入Springboot-web依賴即可,Jackson的相關依賴被包含在Springboot-web中。
二、在springboot的配置文件中新增配置項內容如下:
# 日期格式化 spring.jackson.date-format=yyyy-MM-dd HH:mm:ss # 設置時區(qū) spring.jackson.time-zone=GMT+8 # 設置空如何序列化 spring.jackson.default-property-inclusion=non_null # 格式化輸出 spring.jackson.serialization.indent_output=true # 忽略無法轉換的對象 spring.jackson.serialization.fail_on_empty_beans=false # 允許對象忽略json中不存在的屬性 spring.jackson.deserialization.fail_on_unknown_properties=false # 允許出現(xiàn)特殊字符和轉義符 spring.jackson.parser.allow_unquoted_control_chars=true # 允許出現(xiàn)單引號 spring.jackson.parser.allow_single_quotes=true
三、新增工具類JsonUtil
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.List;
/**
* @Author liboshuai
* @Date 2023/12/18 18:03
*/
@Slf4j
public class JsonUtil {
private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
private static final ObjectMapper OBJECT_MAPPER_SNAKE_CASE = new ObjectMapper();
// 日期格式化
private static final String STANDARD_FORMAT = "yyyy-MM-dd HH:mm:ss";
static {
//對象的所有字段全部列入
OBJECT_MAPPER.setSerializationInclusion(JsonInclude.Include.ALWAYS);
//取消默認轉換timestamps形式
OBJECT_MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
//忽略空Bean轉json的錯誤
OBJECT_MAPPER.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
//所有的日期格式都統(tǒng)一為以下的樣式,即yyyy-MM-dd HH:mm:ss
OBJECT_MAPPER.setDateFormat(new SimpleDateFormat(STANDARD_FORMAT));
//忽略 在json字符串中存在,但是在java對象中不存在對應屬性的情況。防止錯誤
OBJECT_MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
}
static {
//對象的所有字段全部列入
OBJECT_MAPPER_SNAKE_CASE.setSerializationInclusion(JsonInclude.Include.ALWAYS);
//取消默認轉換timestamps形式
OBJECT_MAPPER_SNAKE_CASE.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
//忽略空Bean轉json的錯誤
OBJECT_MAPPER_SNAKE_CASE.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
//所有的日期格式都統(tǒng)一為以下的樣式,即yyyy-MM-dd HH:mm:ss
OBJECT_MAPPER_SNAKE_CASE.setDateFormat(new SimpleDateFormat(STANDARD_FORMAT));
//忽略 在json字符串中存在,但是在java對象中不存在對應屬性的情況。防止錯誤
OBJECT_MAPPER_SNAKE_CASE.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
//轉換為下劃線
OBJECT_MAPPER_SNAKE_CASE.setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE);
}
private JsonUtil() {
}
/**
* 對象轉Json格式字符串
*
* @param obj 對象
* @return Json格式字符串
*/
public static <T> String obj2String(T obj) {
if (obj == null) {
return null;
}
try {
return obj instanceof String ? (String) obj : OBJECT_MAPPER.writeValueAsString(obj);
} catch (JsonProcessingException e) {
log.warn("Parse Object to String error : {}", e.getMessage());
return null;
}
}
/**
* 對象轉file
* @param fileName
* @param obj
*/
public static void obj2File(String fileName,Object obj){
if (obj == null){
return;
}
try {
OBJECT_MAPPER.writeValue(new File(fileName),obj);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 對象轉Json格式字符串; 屬性名從駝峰改為下劃線形式
*
* @param obj 對象
* @return Json格式字符串
*/
public static <T> String obj2StringFieldSnakeCase(T obj) {
if (obj == null) {
return null;
}
try {
ObjectMapper objectMapper = OBJECT_MAPPER_SNAKE_CASE;
return obj instanceof String ? (String) obj : objectMapper.writeValueAsString(obj);
} catch (JsonProcessingException e) {
log.warn("Parse Object to String error : {}", e.getMessage());
return null;
}
}
/**
* 字符串轉換為自定義對象; 屬性名從下劃線形式改為駝峰
*
* @param str 要轉換的字符串
* @param clazz 自定義對象的class對象
* @return 自定義對象
*/
public static <T> T string2ObjFieldLowerCamelCase(String str, Class<T> clazz) {
if (StringUtils.isEmpty(str) || clazz == null) {
return null;
}
try {
ObjectMapper objectMapper = OBJECT_MAPPER_SNAKE_CASE;
return clazz.equals(String.class) ? (T) str : objectMapper.readValue(str, clazz);
} catch (Exception e) {
log.warn("Parse String to Object error : {}", e.getMessage());
return null;
}
}
/**
* 字符串轉換為自定義對象(List); 屬性名從下劃線形式改為駝峰
*
* @param str 要轉換的字符串
* @param typeReference 自定義對象的typeReference List 對象
* @return 自定義對象
*/
public static <T> List<T> string2ListFieldLowerCamelCase(String str, TypeReference<List<T>> typeReference) {
if (StringUtils.isEmpty(str) || typeReference == null) {
return null;
}
try {
ObjectMapper objectMapper = OBJECT_MAPPER_SNAKE_CASE;
return objectMapper.readValue(str, typeReference);
} catch (Exception e) {
log.warn("Parse String to Object error : {}", e.getMessage());
return null;
}
}
/**
* 對象轉Json格式字符串(格式化的Json字符串)
*
* @param obj 對象
* @return 美化的Json格式字符串
*/
public static <T> String obj2StringPretty(T obj) {
if (obj == null) {
return null;
}
try {
return obj instanceof String ? (String) obj : OBJECT_MAPPER.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
} catch (JsonProcessingException e) {
log.warn("Parse Object to String error : {}", e.getMessage());
return null;
}
}
/**
* 字符串轉換為自定義對象
*
* @param str 要轉換的字符串
* @param clazz 自定義對象的class對象
* @return 自定義對象
*/
public static <T> T string2Obj(String str, Class<T> clazz) {
if (StringUtils.isEmpty(str) || clazz == null) {
return null;
}
try {
return clazz.equals(String.class) ? (T) str : OBJECT_MAPPER.readValue(str, clazz);
} catch (Exception e) {
log.warn("Parse String to Object error : {}", e.getMessage());
return null;
}
}
/**
* 字符串轉換為自定義字段轉為list
* @param str
* @param typeReference
* @param <T>
* @return
*/
public static <T> T string2Obj(String str, TypeReference<T> typeReference) {
if (StringUtils.isEmpty(str) || typeReference == null) {
return null;
}
try {
return (T) (typeReference.getType().equals(String.class) ? str : OBJECT_MAPPER.readValue(str, typeReference));
} catch (IOException e) {
log.warn("Parse String to Object error", e);
return null;
}
}
public static <T> T string2Obj(String str, Class<?> collectionClazz, Class<?>... elementClazzes) {
JavaType javaType = OBJECT_MAPPER.getTypeFactory().constructParametricType(collectionClazz, elementClazzes);
try {
return OBJECT_MAPPER.readValue(str, javaType);
} catch (IOException e) {
log.warn("Parse String to Object error : {}" + e.getMessage());
return null;
}
}
}
整合完畢
使用案例
創(chuàng)建實體類User,用于后續(xù)測試
import lombok.Data;
import java.util.List;
@Data
public class User {
private String username;
private Integer age;
private List<String> info;
private Long userId;
}
Java對象轉Json
@Test
void obj2string(){
User user = new User();
user.setUsername("clllb");
user.setAge(24);
user.setUserId(1L);
List<String> infoList = new ArrayList<>();
infoList.add("有一百萬");
infoList.add("發(fā)大財");
user.setInfo(infoList);
String json = JacksonUtil.obj2String(user);
System.out.println(json);
}
輸出結果:
{"username":"clllb","age":24,"info":["有一百萬","發(fā)大財"],"userId":1}
Java對象轉Json(駝峰轉下劃線)
@Test
void obj2sringSnakeCase(){
User user = new User();
user.setUsername("clllb");
user.setAge(24);
user.setUserId(11L);
List<String> infoList = new ArrayList<>();
infoList.add("有一百萬");
infoList.add("發(fā)大財");
user.setInfo(infoList);
String json = JacksonUtil.obj2StringFieldSnakeCase(user);
System.out.println(json);
}
輸出結果:
{"username":"clllb","age":24,"info":["有一百萬","發(fā)大財"],"user_id":11}
Java對象轉file對象
@Test
void obj2file(){
User user = new User();
user.setUsername("clllb");
user.setAge(24);
user.setUserId(1L);
List<String> infoList = new ArrayList<>();
infoList.add("有一百萬");
infoList.add("發(fā)大財");
user.setInfo(infoList);
String fileName = "ccccc";
JacksonUtil.obj2File(fileName,user);
}
輸出結果為一個文件,如下圖所示:

Json轉Java對象(下劃線轉駝峰)
@Test
void string2obj(){
String json = "{\"username\":\"clllb\",\"age\":24,\"info\":[\"有一百萬\",\"發(fā)大財\"],\"userId\":11}";
User user = JacksonUtil.string2Obj(json, User.class);
System.out.println(user);
}
輸出結果:
User(username=clllb, age=24, info=[有一百萬, 發(fā)大財], userId=11)
Json轉Java對象集合
@Test
void string2objList(){
String json = "[{\"username\":\"clllb\",\"age\":24,\"info\":[\"有一百萬\",\"發(fā)大財\"],\"userId\":11},\n" +
"{\"username\":\"陳老老老板\",\"age\":25,\"info\":[\"有一千萬\",\"發(fā)大大財\"],\"userId\":12}]";
List<User> user = JacksonUtil.string2Obj(json, new TypeReference<List<User>>(){});
user.forEach(System.out::println);
}
輸出結果:
User(username=clllb, age=24, info=[有一百萬, 發(fā)大財], userId=11)
User(username=陳老老老板, age=25, info=[有一千萬, 發(fā)大大財], userId=12)
Json轉Java對象集合(下劃線轉駝峰)
@Test
void string2objSnakeCase(){
String json = "[{\"username\":\"clllb\",\"age\":24,\"info\":[\"有一百萬\",\"發(fā)大財\"],\"user_id\":11},\n" +
"{\"username\":\"陳老老老板\",\"age\":25,\"info\":[\"有一千萬\",\"發(fā)大大財\"],\"user_id\":12}]";
List<User> user = JacksonUtil.string2ListFieldLowerCamelCase(json, new TypeReference<List<User>>(){});
user.forEach(System.out::println);
}
輸出結果:
User(username=clllb, age=24, info=[有一百萬, 發(fā)大財], userId=11)
User(username=陳老老老板, age=25, info=[有一千萬, 發(fā)大大財], userId=12)
以上就是SpringBoot整合Jackson的過程詳解的詳細內容,更多關于SpringBoot整合Jackson的資料請關注腳本之家其它相關文章!
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