[Spring] Request processing failed; nested exception is java.lang.IllegalArgumentException:No converter found for return value of type: class java.util.HashMap 에러 해결

Spring MVC 에러

원인 : controller에서 json으로 변환이 되지 않음.

No converter found for return value of type: class java.util.HashMap 해결 방법

 

pom.xml에 의존성 추가

<!-- jackson -->
<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-core</artifactId>
  <version>2.9.2</version>
</dependency>
<dependency>
  <groupId>com.fasterxml.jackson.core</groupId>
  <artifactId>jackson-databind</artifactId>
  <version>2.9.2</version>
</dependency>