解決方案一：

在spring配置中增加以下配置：

<mvc:annotation-driven>
       <mvc:message-converters register-defaults="true">
              <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                     <constructor-arg value="UTF-8" />
              </bean>
 
       </mvc:message-converters>
</mvc:annotation-driven>

然後增加以下依賴：

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.9.5</version>
</dependency>
<dependency>
    <groupId>
 
com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.5</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>
 
2.9.5</version>
</dependency>