如何将Java对象转换为JSON字符串？
下面的示例演示如何使用Jackson将Java对象转换为JSON字符串。JacksonprovideObjectMapper类提供了读写JSON数据的功能。writeValueAsString(Object)方法，用于将任何Java对象序列化为字符串。
package org.nhooo.example.jackson;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class ObjectToJson {
public static void main(String[] args) {
Artist artist = new Artist();
artist.setId(1L);
artist.setName("The Beatles");
ObjectMapper mapper = new ObjectMapper();
try {
String json = mapper.writeValueAsString(artist);
System.out.println("JSON = " + json);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
}
}运行上面的代码片段将打印出以下结果：
JSON = {"id":1,"name":"The Beatles"}这是Artist类的定义。
package org.nhooo.example.jackson;
public class Artist {
private Long id;
private String name;
public Artist() {
}
public Artist(Long id, String name) {
this.id = id;
this.name = name;
}
// Getters & Setters
@Override
public String toString() {
return "Artist{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}Maven依赖
<!-- http://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-core/2.8.6/jackson-core-2.8.6.jar -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.8.6</version>
</dependency>
<!-- http://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-annotations/2.8.6/jackson-annotations-2.8.6.jar -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.8.6</version>
</dependency>
<!-- http://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-databind/2.8.6/jackson-databind-2.8.6.jar -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.6</version>
</dependency>