Spring Integration + filter +向REST控制器发送400错误请求

<int-http:inbound-gateway request-channel="requestChannel" path="/api/endpoint" supported-methods="GET">
    <int-http:request-mapping consumes="application/json" produces="application/json"/>
</int-http:inbound-gateway>

<int:channel id="requestChannel"/>

<int:filter input-channel="requestChannel" output-channel="filteredChannel">
    <bean class="com.example.RequestFilter"/>
</int:filter>

<int:channel id="filteredChannel"/>

<int-http:outbound-gateway request-channel="filteredChannel" url="http://localhost:8080/api/endpoint" http-method="GET"/>

public class RequestFilter implements MessageSelector {

    @Override
    public boolean accept(Message<?> message) {
        // 检查请求的有效性，如果不符合要求，返回false
        if (!isValidRequest(message)) {
            // 返回400错误响应
            throw new MessagingException(HttpStatus.BAD_REQUEST.getReasonPhrase(), HttpStatus.BAD_REQUEST);
        }
        return true;
    }

    private boolean isValidRequest(Message<?> message) {
        // 检查请求的有效性的逻辑判断
        // 返回true或false
    }
}