使用dubbo拦截器遇到的坑

1.新建日志拦截器，引入的包是com.alibaba.dubbo.rpc

import com.alibaba.dubbo.rpc.*;

public class LogFilter implements Filter {
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        return null;
    }
}

当写了测试类启动后，报错：

Caused by: org.xml.sax.SAXParseException; systemId: http://code.alibabatech.com/schema/dubbo/dubbo.xsd; lineNumber: 6; columnNumber: 68; TargetNamespace.1: 应为名称空间 'http://code.alibabatech.com/schema/dubbo', 但方案文档的目标名称空间为 'http://dubbo.apache.org/schema/dubbo'。
	at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
	at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:134)
	at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:396)
	at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaErr(XSDHandler.java:4154)
	at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaError(XSDHandler.java:4137)
	at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.constructTrees(XSDHandler.java:828)
	at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.parseSchema(XSDHandler.java:625)
	at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema(XMLSchemaLoader.java:610)
	at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.findSchemaGrammar(XMLSchemaValidator.java:2447)
	at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(XMLSchemaValidator.java:1768)
	at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.emptyElement(XMLSchemaValidator.java:761)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:351)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2784)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
	at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
	at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:77)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument(XmlBeanDefinitionReader.java:429)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:391)
	... 54 more

2.在网上很少搜到此类问题，感觉要头疼了，去看了rpc的原理，启发后去查找项目中maven引入dubbo的jar包为：

<dependency>
          <groupId>org.apache.dubbo</groupId>
          <artifactId>dubbo</artifactId>
          <version>2.7.0</version>
      </dependency>

3.终于知道是冲突了，所以把包引用改成apache的就正常了

import org.apache.dubbo.rpc.*;

public class LogFilter implements Filter {
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        return null;
    }
}

注：在这过程中还遇到一个问题：
Caused by: org.xml.sax.SAXParseException: cvc-elt.1: 找不到元素 ‘beans’ 的声明。
这是因为在xml配置中配置了xsd的版本号所致：

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
	xsi:schemaLocation="http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
	http://www.springframework.org/schema/beans/spring-beans.xsd
	http://code.alibabatech.com/schema/dubbo
	http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
</beans>

所以不需要版本号：

<beans xmlns="http://www.springframework.org/schema/beans"
	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	   xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
	   xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans.xsd
	http://code.alibabatech.com/schema/dubbo
	http://code.alibabatech.com/schema/dubbo/dubbo.xsd">

安静的解决问题中…