将类型 \'java.lang.String\' 的属性值转换为属性 \'onFailureExpression\' 所需的类型 \'org.springframework.expression.Expression\'

Question

我面临以下错误并使用 spring 版本 5.3.14 和 Spring_integration 5.5.7 并使用 camel 版本 2.25.4。

  org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.expression.Expression' for property 'onFailureExpression'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.expression.Expression' for property 'onFailureExpression': no matching editors or conversion strategy found

配置文件：

<int:filter id="xpathfilter" input-channel="eventSpringXpathChannel"
        output-channel="eventSpringOutChannel" discard-channel="eventSpringFailureChannel"
        expression="#xpath(payload, headers.get('xpathKey'), 'boolean')">
        <int:request-handler-advice-chain>
<bean           class="org.springframework.integration.handler.advice.ExpressionEvaluatingRequestHandlerAdvice">
    <property name="onFailureExpression" value="payload" />
    <property name="failureChannel" ref="eventSpringXpathErrorChannel" />
    <property name="trapException" value="true" />
</bean>
        </int:request-handler-advice-chain>
    </int:filter>

Answer 1

该 setter 需要 org.springframework.expression.Expression 的实例，但您只提供了 value="payload"，这实际上不是 Expression。

看另一个二传手：

/**
 * Set the expression to evaluate against the root message after a failed
 * handler invocation. The exception is available as the variable {@code #exception}.
 * Defaults to {@code payload}, if {@code failureChannel} is configured.
 * @param onFailureExpression the SpEL expression.
 * @since 4.3.7
 */
public void setOnFailureExpressionString(String onFailureExpression) {

因此，您的配置将如下所示：

<property name="onFailureExpressionString" value="payload" />