1. 添加项目依赖
    <dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-databind</artifactId>
 <version>2.8.6</version>
</dependency>
<dependency>
 <groupId>commons-beanutils</groupId>
 <artifactId>commons-beanutils</artifactId>
 <version>1.9.2</version>
</dependency>
<dependency>
 <groupId>org.codehaus.jackson</groupId>
 <artifactId>jackson-mapper-asl</artifactId>
 <version>1.9.13</version>
</dependency>
<dependency>
 <groupId>org.codehaus.jackson</groupId>
 <artifactId>jackson-core-asl</artifactId>
 <version>1.9.13</version>
</dependency>
  2. 在方法上添加@ResponseBody