# JAXB 将对象转换为 JSON 的示例 > 原文： [https://howtodoinjava.com/jaxb/convert-object-to-json-moxy/](https://howtodoinjava.com/jaxb/convert-object-to-json-moxy/) Java 示例**将 Java 对象转换为 JSON 字符串**或将 JSON 写入文件。 本示例将 [MOXy](https://wiki.eclipse.org/EclipseLink/Examples/MOXy) 与 JAXB 一起使用，以**将 Java 对象编组为 JSON**。 MOXy 实现 JAXB，使开发人员可以通过注解提供其映射信息，并提供 JAXB 默认不提供的许多丰富功能。 ## 1\. MOXy 依赖 包括 MOXy 到项目运行时。 ```java <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.moxy</artifactId> <version>2.5.2</version> </dependency> ``` ## 2\. Java 对象到 JSON 字符串 #### 2.1 添加 JAXB 注解 ```java @XmlRootElement(name = "employee") @XmlAccessorType(XmlAccessType.PROPERTY) public class Employee implements Serializable { private static final long serialVersionUID = 1L; private Integer id; private String firstName; private String lastName; private Department department; public Employee() { super(); } //Setters and Getters } ``` ```java @XmlRootElement(name = "department") @XmlAccessorType(XmlAccessType.PROPERTY) public class Department implements Serializable { private static final long serialVersionUID = 1L; Integer id; String name; public Department() { super(); } //Setters and Getters } ``` #### 2.2 添加`jaxb.properties` 当您获得`JAXBContext`的实例时，JAXB 将检查`jaxb.properties`文件并构造上下文。 在这里，您从 MOXy 库中注入了`JAXBContextFactory`。 > 将`jaxb.properties`文件放在放置 JAXB 注解类的同一包中。 ```java javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory ``` #### 2.3 将对象转换为 JSON 现在使用`javax.xml.bind.Marshaller`类将对象转换为 json。 ```java package com.howtodoinjava.demo; import java.io.StringWriter; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import org.eclipse.persistence.jaxb.MarshallerProperties; import com.howtodoinjava.demo.model.Department; import com.howtodoinjava.demo.model.Employee; public class JaxbExample { public static void main(String[] args) { Employee employee = new Employee(1, "Lokesh", "Gupta", new Department(101, "IT")); jaxbObjectToJSON(employee); } private static void jaxbObjectToJSON(Employee employee) { try { JAXBContext jaxbContext = JAXBContext.newInstance(Employee.class); Marshaller jaxbMarshaller = jaxbContext.createMarshaller(); // To format JSON jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE); //Set JSON type jaxbMarshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json"); jaxbMarshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, true); //Print JSON String to Console StringWriter sw = new StringWriter(); jaxbMarshaller.marshal(employee, sw); System.out.println(sw.toString()); } catch (JAXBException e) { e.printStackTrace(); } } } ``` 程序输出： ```java { "employee" : { "department" : { "id" : 101, "name" : "IT" }, "firstName" : "Lokesh", "id" : 1, "lastName" : "Gupta" } } ``` > 阅读更多：[将 Java 对象转换为 XML](https://howtodoinjava.com/jaxb/write-object-to-xml/) ## 3\. Java 对象到 JSON 文件 使用上面的代码，现在输出到 json 文件。 ```java package com.howtodoinjava.demo; import java.io.File; import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Marshaller; import org.eclipse.persistence.jaxb.MarshallerProperties; import com.howtodoinjava.demo.model.Department; import com.howtodoinjava.demo.model.Employee; public class JaxbExample { public static void main(String[] args) { Employee employee = new Employee(1, "Lokesh", "Gupta", new Department(101, "IT")); jaxbObjectToJSON(employee); } private static void jaxbObjectToJSON(Employee employee) { try { JAXBContext jaxbContext = JAXBContext.newInstance(Employee.class); Marshaller jaxbMarshaller = jaxbContext.createMarshaller(); // To format JSON jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE); //Set JSON type jaxbMarshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json"); jaxbMarshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, true); //Store JSON to File File file = new File("employee.json"); jaxbMarshaller.marshal(employee, file); } catch (JAXBException e) { e.printStackTrace(); } } } ``` 程序输出： ```java { "employee" : { "department" : { "id" : 101, "name" : "IT" }, "firstName" : "Lokesh", "id" : 1, "lastName" : "Gupta" } } ``` 请在评论部分将该 json 转换示例**相关的问题**发送给我。 学习愉快！