Question

我正在创建简单的java Web应用程序，通过JPA2（使用Datanucleus）将一行数据写入HBase表，除了写入2个重复的行而不是只写1行

结果

ROW                                        COLUMN+CELL                                                                                                              
 402881813acfed78013acfed78e00000          column=ACCOUNT_TABLE:FIRSTNAME, timestamp=1352108207916, value=testname                                                     
 402881813acfed78013acfed78e00000          column=ACCOUNT_TABLE:ID, timestamp=1352108207916, value=402881813acfed78013acfed78e00000                                 
 402881813acfed78013acfed78e00000          column=ACCOUNT_TABLE:LASTNAME, timestamp=1352108207916, value=testname2                                                     
 402881813acfed78013acfed78e00000          column=ACCOUNT_TABLE:LEVEL, timestamp=1352108207916, value=\x00\x00\x00\x03                                              
 402881813acfed78013acfedf7e20001          column=ACCOUNT_TABLE:FIRSTNAME, timestamp=1352108210172, value=testname                                                     
 402881813acfed78013acfedf7e20001          column=ACCOUNT_TABLE:ID, timestamp=1352108210172, value=402881813acfed78013acfedf7e20001                                 
 402881813acfed78013acfedf7e20001          column=ACCOUNT_TABLE:LASTNAME, timestamp=1352108210172, value=testname2                                                     
 402881813acfed78013acfedf7e20001          column=ACCOUNT_TABLE:LEVEL, timestamp=1352108210172, value=\x00\x00\x00\x03                                              
2 row(s) in 0.1270 seconds

pom.xml中的Datanucleus版本

<org.datanucleus-version>3.1.1</org.datanucleus-version>

pom.xml中的依赖项

 <dependencies>
        <!-- JPA 2.0 Spec -->
        <dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-jpa_2.0_spec</artifactId>
            <version>1.1</version>
        </dependency>

        <!-- JDO API -->
        <dependency>
            <groupId>javax.jdo</groupId>
            <artifactId>jdo-api</artifactId>
            <version>3.0</version>
        </dependency>

        <!-- DataNucleus HBase -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-hbase</artifactId>
            <version>${org.datanucleus-version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
            <version>1.0.4</version>
            <exclusions>
                <exclusion>
                    <groupId>org.codehaus.jackson</groupId>
                    <artifactId>jackson-mapper-asl</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.codehaus.jackson</groupId>
                    <artifactId>jackson-core-asl</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase</artifactId>
            <version>0.94.0</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.3</version>
        </dependency>

        <!-- DataNucleus Core -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-core</artifactId>
            <version>${org.datanucleus-version}</version>
            <scope>runtime</scope>
        </dependency>

        <!-- DataNucleus Enhancer -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-enhancer</artifactId>
            <version>${org.datanucleus-version}</version>
        </dependency>

        <!-- DataNucleus JPA api -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-api-jpa</artifactId>
            <version>${org.datanucleus-version}</version>
        </dependency>

pom.xml中的插件

           <plugin>
                <groupId>org.datanucleus</groupId>
                <artifactId>maven-datanucleus-plugin</artifactId>
                <version>${org.datanucleus-version}</version>
                <configuration>
                    <api>JPA</api>
                    <log4jConfiguration>${basedir}/log4j.properties</log4jConfiguration>
                    <verbose>true</verbose>
                    <persistenceUnitName>hbase-test</persistenceUnitName>
                </configuration>
                <executions>
                    <execution>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>enhance</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

Account.java

package org.test.model;
import javax.persistence.*;
import java.io.Serializable;

@Entity
@Table(name = "ACCOUNT_TABLE")
public class Account implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @Column(name = "ACCOUNT_TABLE:ID")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private String id;

    @Column(name = "ACCOUNT_TABLE:FIRSTNAME")
    private String firstName;

    @Column(name = "ACCOUNT_TABLE:LASTNAME")
    private String lastName;

    @Column(name = "ACCOUNT_TABLE:LEVEL")
    private int level = 0;

    public Account() {
    }

    public Account(String firstName, String lastName, int level) {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.level = level;
    }

    public int getLevel() {
        return level;
    }

    public void setLevel(int level) {
        this.level = level;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
}

的persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">

    <persistence-unit name="hbase-test" transaction-type="RESOURCE_LOCAL">
        <provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider>
        <mapping-file>org/test/model/orm.xml</mapping-file>
        <class>org.test.model.Account</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>

        <properties>
            <property name="datanucleus.storeManagerType" value="hbase" />
            <property name="datanucleus.ConnectionURL" value="hbase:localhost:60010"/>
            <property name="datanucleus.ConnectionUserName" value=""/>
            <property name="datanucleus.ConnectionPassword" value=""/>
            <property name="datanucleus.autoCreateSchema" value="true"/>
            <property name="datanucleus.autoCreateTables" value="true" />
            <property name="datanucleus.autoCreateColumns" value="true" />
            <property name="datanucleus.validateTables" value="true"/>
            <property name="datanucleus.validateConstraints" value="false"/>
            <property name="datanucleus.Optimistic" value="false"/>
            <property name="datanucleus.Multithreaded" value="true" />
        </properties>
    </persistence-unit>
</persistence>

orm.xml中

<?xml version="1.0" encoding="UTF-8" ?>
    <entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_1_0.xsd" version="1.0">
        <description>JPA Mapping file for Test</description>
        <package>org.test.model</package>
        <entity class="org.test.model.Account" name="Account">
            <table name="ACCOUNT_TABLE" />
            <attributes>
                <id name="id">
                    <generated-value strategy="AUTO"/>
                </id>
                <basic name="firstName">
                    <column name="ACCOUNT_TABLE:FIRSTNAME"/>
                </basic>
                <basic name="lastName">
                    <column name="ACCOUNT_TABLE:LASTNAME"/>
                </basic>
                <basic name="level">
                    <column name="ACCOUNT_TABLE:LEVEL"/>
                </basic>
            </attributes>
        </entity>
    </entity-mappings>

TestAddAccountRow.java

package org.test.app;

import org.test.model.Account;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;

public class TestAddAccountRow {
    public void addAccount() {
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("hbase-test");
        EntityManager em = emf.createEntityManager();
        EntityTransaction tx = null;
        Account a2 = new Account("testname","testname2",3);
        tx = em.getTransaction();
        tx.begin();
        em.persist(a2);
        tx.commit();
    }
}

Answer 1

<强>更新

@Datanucleus

我在Spring mvc控制器中调用了DAO（添加了Account对象）的代码，我不知道为什么但这会导致重复行，Datanucleus工作正常。

~~虽然我找不到创建重复行的原因，但我为Datanucleus换出了Kundera它似乎解决了重复行的问题~~

~~我认为Datanucleus~~

中存在错误

昆德拉版本号

<kundera-version>2.1</kundera-version>

pom.xml依赖项

        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>persistence-api</artifactId>
            <version>2.0</version>
        </dependency>

        <dependency>
            <groupId>com.impetus.core</groupId>
            <artifactId>kundera-core</artifactId>
            <version>${kundera-version}</version>
        </dependency>

        <dependency>
            <groupId>com.impetus.client</groupId>
            <artifactId>kundera-hbase</artifactId>
            <version>${kundera-version}</version>
            <exclusions>
            <exclusion>
                <groupId>org.apache.hbase</groupId>
                <artifactId>hbase</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-core</artifactId>
            </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>commons-collections</groupId>
            <artifactId>commons-collections</artifactId>
            <version>3.2.1</version>
        </dependency>

        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>com.impetus.kundera.rest</groupId>
            <artifactId>kundera-rest</artifactId>
            <version>${kundera-version}</version>
        </dependency>

        <!-- HBase and Hadoop -->
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
            <version>1.0.4</version>
            <exclusions>
                <exclusion>
                    <groupId>org.codehaus.jackson</groupId>
                    <artifactId>jackson-mapper-asl</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.codehaus.jackson</groupId>
                    <artifactId>jackson-core-asl</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase</artifactId>
            <version>0.94.0</version>
        </dependency>

的persistence.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!--
  Copyright (C) 2010 Bartosch Warzecha, Matthias Weßendorf

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
    http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
             version="2.0">

    <persistence-unit name="hbase">
        <provider>com.impetus.kundera.KunderaPersistence</provider>
        <class>org.test.model.Account</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <properties>
            <property name="kundera.nodes" value="localhost" />
            <property name="kundera.port" value="60010" />
            <property name="kundera.keyspace" value="test" />
            <property name="kundera.dialect" value="hbase" />
            <property name="kundera.client.lookup.class" value="com.impetus.client.hbase.HBaseClientFactory" />
            <property name="kundera.cache.provider.class"
                      value="com.impetus.kundera.cache.ehcache.EhCacheProvider" />
            <property name="kundera.cache.config.resource" value="/ehcache-test.xml" />
            <property name="kundera.ddl.auto.prepare" value="create" />
        </properties>
    </persistence-unit>
</persistence>

JPA2与HBase数据存储使用Datanucleus写入重复行

1 个答案: