坑#Spring Cloud Gateway#DataBufferLimitException

现象

POST请求数据量大(Content-Length: 305000+)的时候Gateway报错, 报错栈如下：

复制代码

org.springframework.core.io.buffer.DataBufferLimitException: Exceeded limit on max bytes to buffer : 262144
	at org.springframework.core.io.buffer.LimitedDataBufferList.raiseLimitException(LimitedDataBufferList.java:99)

尝试修改max-in-memory-size配置无效

原因

在Gateway配置文件routes节点中使用了CacheRequestBody

复制代码

public class CacheRequestBodyGatewayFilterFactory
       extends AbstractGatewayFilterFactory<CacheRequestBodyGatewayFilterFactory.Config> {

    private final List<HttpMessageReader<?>> messageReaders;

    public CacheRequestBodyGatewayFilterFactory() {
       super(CacheRequestBodyGatewayFilterFactory.Config.class);
       // 这块有问题
       this.messageReaders = HandlerStrategies.withDefaults().messageReaders();
    }
}

解决

方式一

参考: https://github.com/spring-cloud/spring-cloud-gateway/issues/1658

复制代码

import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.cloud.gateway.filter.factory.CacheRequestBodyGatewayFilterFactory;
import org.springframework.util.ReflectionUtils;
import java.lang.reflect.Field;

@Bean
public BeanPostProcessor cacheRequestBodyGatewayFilterFactoryBeanPostProcessor() {
    return new BeanPostProcessor() {
        @Override
        public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
            if (bean instanceof CacheRequestBodyGatewayFilterFactory cacheFactoryBean) {
                // use java reflection to replace messageReaders in CacheRequestBodyGatewayFilterFactory
                // with message readers configured from CodecConfigurer
                Field messageReadersField = ReflectionUtils.findField(CacheRequestBodyGatewayFilterFactory.class,
                        "messageReaders");
                messageReadersField.setAccessible(true);
                ReflectionUtils.setField(messageReadersField, cacheFactoryBean, codecConfigurer.getReaders());
                messageReadersField.setAccessible(false);
                return cacheFactoryBean;
            }
            return bean;
        }
    };
}

方式二

参考: https://blog.csdn.net/fujiakai/article/details/134972127

重写org.springframework.core.codec.AbstractDataBufferDecoder类

在当前项目创建相同包名和类名文件

调整maxInMemorySize默认值大小即可