HTTP Status 500 - Internal Server Error: No converter found for return value of type: class xxx (simple analysis and solution)

Problem Description

The following content is based on the ssm framework. When we initiate a request to the tomcat server, the following error status prompt –500 appears.

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Tomcat日志信息：

Cause Analysis:

No converter found for return value of type: class com.ssm.utils.Msg, an exception occurred while binding data using jackson.

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solution:

Check 1: Whether to add jackson's related dependencies to pom.xml

		<!--jackson数据绑定相关依赖jar开始-->
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!--jackson数据绑定相关依赖jar结束-->

Check 2: Whether the gettter/setter method has been added to the wrong class.

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Check 3: Whether the spring-mvc annotation driver has been enabled.

    <!--开启注解驱动 配置最新的处理器映射器 处理适配器-->
    <mvc:annotation-driven/>

Check 4: Whether the annotation @ResponseBody or @RequestParam has been added.

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Check five: If the passed parameter is a java entity class object, you need to add @RequestBody in front and implement the serialization method of the entity class.

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Check 6: When you reach this step and still have not solved the problem, please confirm whether the jar package of jackson has been added to the lib directory.