# 71.2 编写XML REST服务

如果classpath下存在Jackson XML扩展（`jackson-dataformat-xml`），它会被用来渲染XML响应，示例和JSON的非常相似。想要使用它，只需为你的项目添加以下依赖：

```markup
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
</dependency>
```

你可能还需要添加Woodstox的依赖，它比JDK提供的默认StAX实现快很多，并且支持良好的格式化输出，提高了namespace处理能力：

```markup
<dependency>
    <groupId>org.codehaus.woodstox</groupId>
    <artifactId>woodstox-core-asl</artifactId>
</dependency>
```

如果Jackson的XML扩展不可用，Spring Boot将使用JAXB（JDK默认提供），不过`MyThing`需要注解`@XmlRootElement`：

```java
@XmlRootElement
public class MyThing {
    private String name;
    // .. getters and setters
}
```

想要服务器渲染XML而不是JSON，你可能需要发送一个`Accept: text/xml`头部（或使用浏览器）。


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