使用Spring Data Jpa Module在MySQL数据库中插入数据时遇到问题。
问题如下： 当我启动SpringApplication时，我创建数据库并使用SpringdataJPA初始化数据，我看到表中插入的数据。之后我想插入一些与插入数据相关的数据，之前插入的3条记录中只有1条被找到。当我重新启动服务器并且我不重新创建数据并使用相同的方法搜索它时，每个记录都被找到。我搜索了2周的解决方案，但没有找到任何东西。我希望你能帮助我。
新闻
我认为只用语言很难理解，所以我插入代码。带有所有spring jpa配置的jpa.xml。 2个实体和init方法。希望你能找到我的错误。
jpa.xml：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:property-placeholder location="classpath:properties/database/database.properties" />
<!-- Declare a datasource that has pooling capabilities-->
<!-- BoneCP configuration -->
<bean id="SoopDataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close" >
<property name="driverClass" value="${database.driver}" />
<property name="jdbcUrl" value="${database.url}" />
<property name="username" value="${database.user}"/>
<property name="password" value="${database.password}"/>
<property name="idleConnectionTestPeriod" value="60"/>
<property name="idleMaxAge" value="240"/>
<property name="maxConnectionsPerPartition" value="30"/>
<property name="minConnectionsPerPartition" value="5"/>
<property name="partitionCount" value="2"/>
<property name="acquireIncrement" value="5"/>
<!-- <property name="statementsCacheSize" value="100"/> -->
<!-- <property name="releaseHelperThreads" value="2"/> -->
</bean>
<!-- Declare a JPA entityManagerFactory-->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" >
<property name="persistenceUnitName" value="SoopDbProvider" />
<property name="dataSource" ref="SoopDataSource"/>
<property name="persistenceProviderClass" value="org.hibernate.ejb.HibernatePersistence"/>
<property name="jpaProperties">
<props>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.temp.use_jdbc_metadata_defaults">false</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</prop>
<prop key="hibernate.hbm2ddl.auto">create</prop>
</props>
</property>
<property name="packagesToScan">
<list>
<value>com.soopproject.main.db</value>
</list>
</property>
</bean>
<!-- Db initialization bean -->
<bean id="databaseinit" class="com.soopproject.main.db.init.DatabaseInitialization" init-method="init"/>
<!-- Declare a transaction manager-->
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
实体：
BaseEntityWithPrimary
@MappedSuperclass
@Data
@EqualsAndHashCode(callSuper = false)
public class SoopBaseEntityWithPrimary implements
Serializable {
@Id
@GeneratedValue
private long id;
}
语言
@Entity
@Data
@EqualsAndHashCode(callSuper = true)
public class Language extends BaseEntityWithPrimary {
@Column(nullable = false, unique = true)
private String shortname;
@Column(nullable = false)
private String longname;
@ManyToMany(cascade = CascadeType.ALL)
private List<TranslationsShort> languageTranslationsShorts;
}
InitMethods
@Autowired
private UserRepository userrep;
@Autowired
private LanguageRepository langrep;
@Autowired
private ErrorCodesRepository errorrep;
private void initLanguage() {
User systemuser = null;
try {
systemuser = userrep.findUserByUsername("system");
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
List<Language> languages = new LinkedList<>();
Language deutsch = new Language();
deutsch.setCreateUser(systemuser);
deutsch.setShortname("DE");
deutsch.setLongname("Deutsch");
Language english = new Language();
english.setCreateUser(systemuser);
english.setShortname("EN");
english.setLongname("English");
Language italiano = new Language();
italiano.setCreateUser(systemuser);
italiano.setShortname("IT");
italiano.setLongname("Italiano");
languages.add(deutsch);
languages.add(italiano);
languages.add(english);
for (Language lang : languages) {
Language l_help = null;
try {
l_help = langrep.findLanguageByShortname(lang.getShortname());
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
if (l_help == null)
try {
langrep.saveAndFlush(lang);
} catch (Exception e) {
DatabaseException exception = new DatabaseWriteException(e);
exception.writeLog();
}
}
}
private void initErrorCodes() {
User systemuser = null;
Language de = null;
Language it = null;
Language en = null;
try {
systemuser = userrep.findUserByUsername("system");
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
try {
de = langrep.findLanguageByShortname("DE");
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
try {
it = langrep.findLanguageByShortname("IT");
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
try {
en = langrep.findLanguageByShortname("EN");
} catch (Exception ex) {
DatabaseException exception = new DatabaseReadException(ex);
exception.writeLog();
}
问题是在启动springapplication并在方法initErrorCodes中设置<prop key="hibernate.hbm2ddl.auto">create</prop>后，只有 it = langrep.findLanguageByShortname（“IT”）; 的行找到数据库中的数据。其他2个调用返回null（de = langrep.findLanguageByShortname（“DE”）;和en = langrep.findLanguageByShortname（“EN”）;）。然后我停止应用程序并查看数据库，所有数据都插入表语言中。当我用<prop key="hibernate.hbm2ddl.auto">none</prop>重新启动服务器时，所有3个方法调用都返回数据???！？！？！我不懂。所以肯定这不是方法调用的问题。但是我找不到错误。
答案 0 :(得分：0)
你的意思是3个中的1个被发现了？您在查询数据或访问关系吗？
听起来好像正在发生某种缓存。某些JPA提供程序默认启用缓存，检查缓存设置，并确保正确维护双向关系。