使用spring的Hbase连接失败答案

【问题标题】：Hbase connection failure using spring使用spring的Hbase连接失败
【发布时间】：2013-03-14 09:48:23
【问题描述】：

我有一个简单的带有 HBase 的 crud 应用程序，只使用了一个 java 客户端，一切都很好。但是当我尝试使用 spring 做同样的应用程序时，zookeeper 拒绝连接或关闭它，我真的不明白会发生什么。这是一些代码： xml配置：

 <beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:hdp="http://www.springframework.org/schema/hadoop"
   xsi:schemaLocation="
    http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/hadoop 
    http://www.springframework.org/schema/hadoop/spring-hadoop.xsd">

    <hdp:configuration>
    </hdp:configuration> 
    <hdp:hbase-configuration delete-connection="true" />
    <bean id="hTemplate" class="org.springframework.data.hadoop.hbase.HbaseTemplate" >
        <property name="configuration" ref="hbaseConfiguration"></property>
    </bean>
    <bean id="usingHBase" class="com.mycompany.usinghbase.UsingHBase" />
 </beans>

这是我的简单方法：

public class UsingHBase {

    @Autowired
    @Qualifier("hTemplate")
    private HbaseTemplate hBaseTemplate;

    public void addData(final String key, final String value) throws IOException {
        hBaseTemplate.execute("new_table", new TableCallback<Object>() {
            public Object doInTable(HTableInterface hti) throws Throwable {
              Put p = new Put(Bytes.toBytes("zz"));
              p.add(Bytes.toBytes("zz"), Bytes.toBytes(key), Bytes.toBytes(value));
                hti.put(p);
                return null;
            }
        });
    }

    public List<Object> findAll() {
        return hBaseTemplate.find("new_table", "zz", new RowMapper<Object>() {
            public Object mapRow(Result result, int rowNum) throws Exception {
                return result.toString();
            }
        });
    }

        public void DeleteData(final String key) throws IOException {
        hBaseTemplate.execute("new_table", new TableCallback<Object>() {
            public Object doInTable(HTableInterface hti) throws Throwable {
        Delete delete = new Delete(Bytes.toBytes("zz"));
        delete.deleteColumns(Bytes.toBytes("zz"), Bytes.toBytes(key));
        hti.delete(delete);
                return null;
            }
        });
    }
}

这是我的测试用例：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "file:src/main/java/spring.xml")
public class UsingHBaseTest {

    @Autowired
    @Qualifier("hTemplate")
    private HbaseTemplate hBaseTemplate;

    @Autowired
    @Qualifier("usingHBase")
    private UsingHBase usingHBase;

    @Before
    public void setUp() {
    }

    @Test
    public void testAddData() throws Exception {
        System.out.println("addData");
        long startTime = System.currentTimeMillis();
    for (int i=1; i <= 1000; i++) {
            String column = "k" + i;
            String value = "v" + i;
            usingHBase.addData(column, value);
    }
    long EndTime = System.currentTimeMillis();
    System.out.println("Put value: " + (EndTime - startTime));
    }

    @Test
    public void testFindAll() {
        System.out.println("findData");
        long startTime = System.currentTimeMillis();
        usingHBase.findAll();
    long EndTime = System.currentTimeMillis();
    System.out.println("Put value: " + (EndTime - startTime));
    } 

    @Test
    public void testDeleteData() throws IOException {
        System.out.println("deleteData");
        long startTime = System.currentTimeMillis();
    for (int i=1; i <= 1000; i++) {
            String column = "k" + i;
            usingHBase.DeleteData(column);
    }
    long EndTime = System.currentTimeMillis();
    System.out.println("delete value: " + (EndTime - startTime));
    }
}

堆栈跟踪说的是什么：

Running com.mycompany.usinghbase.UsingHBaseTest
13/03/25 11:28:57 INFO context.TestContextManager: @TestExecutionListeners is not present for class [class com.mycompany.usinghbase.UsingHBaseTest]: using defaults.
13/03/25 11:28:57 INFO xml.XmlBeanDefinitionReader: Loading XML bean definitions from URL [file:src/main/java/spring.xml]
13/03/25 11:28:59 INFO support.GenericApplicationContext: Refreshing org.springframework.context.support.GenericApplicationContext@26d0fffc: startup date [Mon Mar 25 11:28:59 VLAT 2013]; root of context hierarchy
13/03/25 11:28:59 INFO support.DefaultListableBeanFactory: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@4489140e: defining beans [hadoopConfiguration,hbaseConfiguration,hTemplate,usingHBase,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
addData
2013-03-25 11:29:00.037 java[24078:1c03] Unable to load realm info from SCDynamicStore
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:zookeeper.version=3.4.3-1240972, built on 02/06/2012 10:48 GMT
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:host.name=192.168.0.86
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.version=1.7.0_10
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.vendor=Oracle Corporation
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.home=/Library/Java/JavaVirtualMachines/jdk1.7.0_10.jdk/Contents/Home/jre
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.class.path=/Users/urijvoskresenskij/NetBeansProjects/UsingHBase/target/test-classes:/Users/urijvoskresenskij/NetBeansProjects/UsingHBase/target/classes:/Users/urijvoskresenskij/.m2/repository/org/apache/hbase/hbase/0.94.3/hbase-0.94.3.jar:/Users/urijvoskresenskij/.m2/repository/com/yammer/metrics/metrics-core/2.1.2/metrics-core-2.1.2.jar:/Users/urijvoskresenskij/.m2/repository/com/google/guava/guava/11.0.2/guava-11.0.2.jar:/Users/urijvoskresenskij/.m2/repository/com/google/code/findbugs/jsr305/1.3.9/jsr305-1.3.9.jar:/Users/urijvoskresenskij/.m2/repository/commons-cli/commons-cli/1.2/commons-cli-1.2.jar:/Users/urijvoskresenskij/.m2/repository/commons-configuration/commons-configuration/1.6/commons-configuration-1.6.jar:/Users/urijvoskresenskij/.m2/repository/commons-collections/commons-collections/3.2.1/commons-collections-3.2.1.jar:/Users/urijvoskresenskij/.m2/repository/commons-digester/commons-digester/1.8/commons-digester-1.8.jar:/Users/urijvoskresenskij/.m2/repository/commons-beanutils/commons-beanutils/1.7.0/commons-beanutils-1.7.0.jar:/Users/urijvoskresenskij/.m2/repository/commons-beanutils/commons-beanutils-core/1.8.0/commons-beanutils-core-1.8.0.jar:/Users/urijvoskresenskij/.m2/repository/com/github/stephenc/high-scale-lib/high-scale-lib/1.1.1/high-scale-lib-1.1.1.jar:/Users/urijvoskresenskij/.m2/repository/commons-codec/commons-codec/1.4/commons-codec-1.4.jar:/Users/urijvoskresenskij/.m2/repository/commons-httpclient/commons-httpclient/3.1/commons-httpclient-3.1.jar:/Users/urijvoskresenskij/.m2/repository/commons-io/commons-io/2.1/commons-io-2.1.jar:/Users/urijvoskresenskij/.m2/repository/commons-lang/commons-lang/2.5/commons-lang-2.5.jar:/Users/urijvoskresenskij/.m2/repository/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar:/Users/urijvoskresenskij/.m2/repository/log4j/log4j/1.2.16/log4j-1.2.16.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/avro/avro/1.5.3/avro-1.5.3.jar:/Users/urijvoskresenskij/.m2/repository/org/xerial/snappy/snappy-java/1.0.3.2/snappy-java-1.0.3.2.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/avro/avro-ipc/1.5.3/avro-ipc-1.5.3.jar:/Users/urijvoskresenskij/.m2/repository/org/jboss/netty/netty/3.2.4.Final/netty-3.2.4.Final.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/velocity/velocity/1.7/velocity-1.7.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/zookeeper/zookeeper/3.4.3/zookeeper-3.4.3.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/thrift/libthrift/0.8.0/libthrift-0.8.0.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/httpcomponents/httpclient/4.1.2/httpclient-4.1.2.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/httpcomponents/httpcore/4.1.3/httpcore-4.1.3.jar:/Users/urijvoskresenskij/.m2/repository/org/jruby/jruby-complete/1.6.5/jruby-complete-1.6.5.jar:/Users/urijvoskresenskij/.m2/repository/org/mortbay/jetty/jetty/6.1.26/jetty-6.1.26.jar:/Users/urijvoskresenskij/.m2/repository/org/mortbay/jetty/jetty-util/6.1.26/jetty-util-6.1.26.jar:/Users/urijvoskresenskij/.m2/repository/org/mortbay/jetty/jsp-2.1/6.1.14/jsp-2.1-6.1.14.jar:/Users/urijvoskresenskij/.m2/repository/org/eclipse/jdt/core/3.1.1/core-3.1.1.jar:/Users/urijvoskresenskij/.m2/repository/org/mortbay/jetty/jsp-api-2.1/6.1.14/jsp-api-2.1-6.1.14.jar:/Users/urijvoskresenskij/.m2/repository/org/mortbay/jetty/servlet-api-2.5/6.1.14/servlet-api-2.5-6.1.14.jar:/Users/urijvoskresenskij/.m2/repository/org/codehaus/jackson/jackson-core-asl/1.8.8/jackson-core-asl-1.8.8.jar:/Users/urijvoskresenskij/.m2/repository/org/codehaus/jackson/jackson-mapper-asl/1.8.8/jackson-mapper-asl-1.8.8.jar:/Users/urijvoskresenskij/.m2/repository/org/codehaus/jackson/jackson-jaxrs/1.8.8/jackson-jaxrs-1.8.8.jar:/Users/urijvoskresenskij/.m2/repository/org/codehaus/jackson/jackson-xc/1.8.8/jackson-xc-1.8.8.jar:/Users/urijvoskresenskij/.m2/repository/org/slf4j/slf4j-api/1.4.3/slf4j-api-1.4.3.jar:/Users/urijvoskresenskij/.m2/repository/org/slf4j/slf4j-log4j12/1.4.3/slf4j-log4j12-1.4.3.jar:/Users/urijvoskresenskij/.m2/repository/tomcat/jasper-compiler/5.5.23/jasper-compiler-5.5.23.jar:/Users/urijvoskresenskij/.m2/repository/tomcat/jasper-runtime/5.5.23/jasper-runtime-5.5.23.jar:/Users/urijvoskresenskij/.m2/repository/commons-el/commons-el/1.0/commons-el-1.0.jar:/Users/urijvoskresenskij/.m2/repository/org/jamon/jamon-runtime/2.3.1/jamon-runtime-2.3.1.jar:/Users/urijvoskresenskij/.m2/repository/com/google/protobuf/protobuf-java/2.4.0a/protobuf-java-2.4.0a.jar:/Users/urijvoskresenskij/.m2/repository/com/sun/jersey/jersey-core/1.8/jersey-core-1.8.jar:/Users/urijvoskresenskij/.m2/repository/com/sun/jersey/jersey-json/1.8/jersey-json-1.8.jar:/Users/urijvoskresenskij/.m2/repository/org/codehaus/jettison/jettison/1.1/jettison-1.1.jar:/Users/urijvoskresenskij/.m2/repository/com/sun/xml/bind/jaxb-impl/2.2.3-1/jaxb-impl-2.2.3-1.jar:/Users/urijvoskresenskij/.m2/repository/com/sun/jersey/jersey-server/1.8/jersey-server-1.8.jar:/Users/urijvoskresenskij/.m2/repository/asm/asm/3.1/asm-3.1.jar:/Users/urijvoskresenskij/.m2/repository/javax/xml/bind/jaxb-api/2.1/jaxb-api-2.1.jar:/Users/urijvoskresenskij/.m2/repository/javax/activation/activation/1.1/activation-1.1.jar:/Users/urijvoskresenskij/.m2/repository/stax/stax-api/1.0.1/stax-api-1.0.1.jar:/Users/urijvoskresenskij/.m2/repository/junit/junit/4.11/junit-4.11.jar:/Users/urijvoskresenskij/.m2/repository/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-aop/3.1.2.RELEASE/spring-aop-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-asm/3.1.2.RELEASE/spring-asm-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-context-support/3.1.2.RELEASE/spring-context-support-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/javax/annotation/jsr250-api/1.0/jsr250-api-1.0.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-test/3.1.2.RELEASE/spring-test-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-beans/3.1.2.RELEASE/spring-beans-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-context/3.1.2.RELEASE/spring-context-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-expression/3.1.2.RELEASE/spring-expression-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-core/3.1.2.RELEASE/spring-core-3.1.2.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/data/spring-data-hadoop/1.0.0.RELEASE/spring-data-hadoop-1.0.0.RELEASE.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/hadoop/hadoop-streaming/1.0.4/hadoop-streaming-1.0.4.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/hadoop/hadoop-core/1.0.4/hadoop-core-1.0.4.jar:/Users/urijvoskresenskij/.m2/repository/xmlenc/xmlenc/0.52/xmlenc-0.52.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/commons/commons-math/2.1/commons-math-2.1.jar:/Users/urijvoskresenskij/.m2/repository/commons-net/commons-net/1.4.1/commons-net-1.4.1.jar:/Users/urijvoskresenskij/.m2/repository/net/java/dev/jets3t/jets3t/0.7.1/jets3t-0.7.1.jar:/Users/urijvoskresenskij/.m2/repository/net/sf/kosmosfs/kfs/0.3/kfs-0.3.jar:/Users/urijvoskresenskij/.m2/repository/hsqldb/hsqldb/1.8.0.10/hsqldb-1.8.0.10.jar:/Users/urijvoskresenskij/.m2/repository/oro/oro/2.0.8/oro-2.0.8.jar:/Users/urijvoskresenskij/.m2/repository/org/apache/hadoop/hadoop-tools/1.0.4/hadoop-tools-1.0.4.jar:/Users/urijvoskresenskij/.m2/repository/org/springframework/spring-tx/3.1.2.RELEASE/spring-tx-3.1.2.RELEASE.jar:
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.library.path=/Users/urijvoskresenskij/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.io.tmpdir=/var/folders/_q/z5blmlxs39d4pmmv1fj9mh500000gn/T/
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:java.compiler=<NA>
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:os.name=Mac OS X
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:os.arch=x86_64
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:os.version=10.7.5
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:user.name=urijvoskresenskij
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:user.home=/Users/urijvoskresenskij
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Client environment:user.dir=/Users/urijvoskresenskij/NetBeansProjects/UsingHBase
13/03/25 11:29:01 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
13/03/25 11:29:02 INFO zookeeper.ClientCnxn: Opening socket connection to server /0:0:0:0:0:0:0:1:2181
13/03/25 11:29:02 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 24078@MacBook-Air-Urij.local
13/03/25 11:29:02 INFO client.ZooKeeperSaslClient: Client will not SASL-authenticate because the default JAAS configuration section 'Client' could not be found. If you are not using SASL, you may ignore this. On the other hand, if you expected SASL to work, please fix your JAAS configuration.
13/03/25 11:29:02 INFO zookeeper.ClientCnxn: Socket connection established to localhost/0:0:0:0:0:0:0:1:2181, initiating session
13/03/25 11:29:02 INFO zookeeper.ClientCnxn: Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x13d9ee87e610328, negotiated timeout = 40000
13/03/25 11:29:03 INFO client.HConnectionManager$HConnectionImplementation: Closed zookeeper sessionid=0x13d9ee87e610328
13/03/25 11:29:04 INFO zookeeper.ZooKeeper: Session: 0x13d9ee87e610328 closed
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: EventThread shut down
13/03/25 11:29:04 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
13/03/25 11:29:04 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 24078@MacBook-Air-Urij.local
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Opening socket connection to server /127.0.0.1:2181
13/03/25 11:29:04 INFO client.ZooKeeperSaslClient: Client will not SASL-authenticate because the default JAAS configuration section 'Client' could not be found. If you are not using SASL, you may ignore this. On the other hand, if you expected SASL to work, please fix your JAAS configuration.
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Socket connection established to localhost/127.0.0.1:2181, initiating session
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x13d9ee87e61032c, negotiated timeout = 40000
13/03/25 11:29:04 INFO client.HConnectionManager$HConnectionImplementation: Closed zookeeper sessionid=0x13d9ee87e61032c
13/03/25 11:29:04 INFO zookeeper.ZooKeeper: Session: 0x13d9ee87e61032c closed
13/03/25 11:29:04 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: EventThread shut down
13/03/25 11:29:04 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 24078@MacBook-Air-Urij.local
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Opening socket connection to server /0:0:0:0:0:0:0:1:2181
13/03/25 11:29:04 INFO client.ZooKeeperSaslClient: Client will not SASL-authenticate because the default JAAS configuration section 'Client' could not be found. If you are not using SASL, you may ignore this. On the other hand, if you expected SASL to work, please fix your JAAS configuration.
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Socket connection established to localhost/0:0:0:0:0:0:0:1:2181, initiating session
13/03/25 11:29:04 INFO zookeeper.ClientCnxn: Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x13d9ee87e61032d, negotiated timeout = 40000
13/03/25 11:29:04 INFO client.HConnectionManager$HConnectionImplementation: Closed zookeeper sessionid=0x13d9ee87e61032d
13/03/25 11:29:05 INFO zookeeper.ZooKeeper: Session: 0x13d9ee87e61032d closed
13/03/25 11:29:05 INFO zookeeper.ClientCnxn: EventThread shut down
13/03/25 11:29:05 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
13/03/25 11:29:05 INFO zookeeper.RecoverableZooKeeper: The identifier of this process is 24078@MacBook-Air-Urij.local
13/03/25 11:29:05 INFO zookeeper.ClientCnxn: Opening socket connection to server /fe80:0:0:0:0:0:0:1%1:2181
13/03/25 11:29:10 INFO client.ZooKeeperSaslClient: Client will not SASL-authenticate because the default JAAS configuration section 'Client' could not be found. If you are not using SASL, you may ignore this. On the other hand, if you expected SASL to work, please fix your JAAS configuration.
13/03/25 11:29:10 INFO zookeeper.ClientCnxn: Socket connection established to fe80:0:0:0:0:0:0:1%1/fe80:0:0:0:0:0:0:1%1:2181, initiating session
13/03/25 11:29:11 INFO zookeeper.ClientCnxn: Session establishment complete on server fe80:0:0:0:0:0:0:1%1/fe80:0:0:0:0:0:0:1%1:2181, sessionid = 0x13d9ee87e610334, negotiated timeout = 40000

请帮助，人们。我非常需要你！

【问题讨论】：

看起来您的应用程序没有连接到您的 HBase 安装，这可能有多种原因。您对运行 HBase 的机器是否有无密码 sudo 访问权限？？
不，我不知道。 Hbase 在我的文件夹中，不需要 sudo 访问。我有同样简单的应用程序，但只使用 java 客户端，我的应用程序仍然成功连接到 hbase，但是当我实现 spring（当然是在一个新项目中）时，zookeper 不允许我的客户端连接到 hbase。

标签： spring hadoop hbase apache-zookeeper

【解决方案1】：

您必须在 xml 中指定您的 zookeeper quorum 和端口

<hdp:configuration id="hadoopConfiguration">
    hbase.zookeeper.quorum=mynode
    hbase.zookeeper.property.clientPort=2181
</hdp:configuration> 
<hdp:hbase-configuration id="hbaseConfiguration" delete-connection="true" configuration="hadoopConfiguration" />

【讨论】：

【解决方案2】：

在启动 zookeeper、hbase regionservers 和 master 后尝试运行您的应用程序。然后代码应该可以工作了。

【讨论】：