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?Jpa與Druid線程池及Spring Boot整合(一)

Jpa與Druid線程池及Spring Boot整合(二)：幾個(gè)坑

附錄官網(wǎng)文檔：core.domain-events域事件

從聚合根發(fā)布事件

class AnAggregateRoot {@DomainEvents (1)Collection<Object> domainEvents() {// … return events you want to get published here}@AfterDomainEventPublication (2)void callbackMethod() {// … potentially clean up domain events list}
}

在使用Spring Boot JPA時(shí)，open-in-view 選項(xiàng)默認(rèn)為true。啟動(dòng)時(shí)在日志中會(huì)出現(xiàn)警告。?

一坑：druid與jpa整合，啟動(dòng)出現(xiàn)如下警告：

JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning

?處理方案:

按照日志要求將 open-in-view=false。再次啟動(dòng)，如果在實(shí)體類中外鍵字段使用了懶加載模式，在視圖層中調(diào)用數(shù)據(jù)時(shí)，則會(huì)出現(xiàn) no session 異常。

解決方法：手動(dòng)注冊(cè)O(shè)penEntityManagerInViewFilter過(guò)濾器，改變session的生命周期，當(dāng)web請(qǐng)求關(guān)閉時(shí)才結(jié)束session。
?

? javaConfig注入bean

@Bean
public FilterRegistrationBean<OpenEntityManagerInViewFilter> registerOpenEntityManagerInViewFilterBean() {FilterRegistrationBean<OpenEntityManagerInViewFilter> registrationBean = new FilterRegistrationBean<>();OpenEntityManagerInViewFilter filter = new OpenEntityManagerInViewFilter();registrationBean.setFilter(filter);registrationBean.setOrder(5);return registrationBean;
}

解疑：

如果使用的是 JPA 則對(duì)應(yīng)OpenEntityManagerInViewFilter,Hibernate對(duì)應(yīng)OpenSessionInViewFilter
疑問(wèn)：

registrationBean.setOrder(5)，order為什么是5
OpenSessionInViewInterceptor&OpenSessionInViewFilter,OpenEntityManagerInViewInterceptor&OpenEntityManagerInViewFilter這幾個(gè)類的區(qū)別以及使的的場(chǎng)景
?

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重新啟動(dòng): 正常：

二坑:? ?springboot整合JPA出現(xiàn)異常java.lang.IllegalArgumentException: Not a managed type: class xx

方案: 一

啟動(dòng)類或者JavaConfig添加添加掃描實(shí)體的路徑:
@EntityScan(basePackages = "org.jd.websocket.auth.data.reactor.jpa")
@EnableTransactionManagement // 開啟事務(wù)的支持
@EnableJpaRepositories(basePackages = {"org.jd.websocket.auth.data.reactor.repository","org.jd.websocket.auth.data.reactor.jpa"},includeFilters = {@ComponentScan.Filter(type = FilterType.REGEX, pattern = ".*CrudRepository")},excludeFilters = {@ComponentScan.Filter(type = FilterType.REGEX, pattern = ".*SomeOtherRepository")})

?方案: 二

@Configuration? ? ?javaConfig中注入Bean

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();vendorAdapter.setGenerateDdl(true);LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();factory.setJpaVendorAdapter(vendorAdapter);// entity掃描的包路徑factory.setPackagesToScan("org.jd.websocket.auth.data.reactor.jpa");factory.setDataSource(dataSource());return factory;
}

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@Value("${spring.datasource.url}")
private String dbUrl;@Value("${spring.datasource.username}")
private String username;
@Value("${spring.datasource.password}")
private String password;
@Value("${spring.datasource.driver-class-name}")
private String driverClassName;@Value("${spring.datasource.initialSize}")
private int initialSize;
@Value("${spring.datasource.minIdle}")
private int minIdle;
@Value("${spring.datasource.maxActive}")
private int maxActive;
@Value("${spring.datasource.maxWait}")
private int maxWait;
@Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;
@Value("${spring.datasource.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;
@Value("${spring.datasource.validationQuery}")
private String validationQuery;
@Value("${spring.datasource.testWhileIdle}")
private boolean testWhileIdle;
@Value("${spring.datasource.testOnBorrow}")
private boolean testOnBorrow;
@Value("${spring.datasource.testOnReturn}")
private boolean testOnReturn;
@Value("${spring.datasource.poolPreparedStatements}")
private boolean poolPreparedStatements;
@Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
private int maxPoolPreparedStatementPerConnectionSize;
@Value("${spring.datasource.filters}")
private String filters;
@Value("{spring.datasource.connectionProperties}")
private String connectionProperties;@Bean
@Primary
public DataSource dataSource() {DruidDataSource datasource = new DruidDataSource();datasource.setUrl(dbUrl);datasource.setUsername(username);datasource.setPassword(password);datasource.setDriverClassName(driverClassName);// configurationdatasource.setInitialSize(initialSize);datasource.setMinIdle(minIdle);datasource.setMaxActive(maxActive);datasource.setMaxWait(maxWait);datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);datasource.setValidationQuery(validationQuery);datasource.setTestWhileIdle(testWhileIdle);datasource.setTestOnBorrow(testOnBorrow);datasource.setTestOnReturn(testOnReturn);datasource.setPoolPreparedStatements(poolPreparedStatements);datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);try {datasource.setFilters(filters);} catch (SQLException e) {System.err.println("druid configuration initialization filter: " + e);}datasource.setConnectionProperties(connectionProperties);return datasource;
}@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();vendorAdapter.setGenerateDdl(true);LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();factory.setJpaVendorAdapter(vendorAdapter);// entity掃描的包路徑factory.setPackagesToScan("org.jd.websocket.auth.data.reactor.jpa");factory.setDataSource(dataSource());return factory;
}

坑三:? ? 多數(shù)據(jù)源注入,事務(wù)失效|解決方案;

* @Transactiona在多數(shù)據(jù)源下失效
* 在多數(shù)據(jù)源的情況下，如果transactionManager進(jìn)行了分開配置，比如這里針對(duì)三個(gè)數(shù)據(jù)源配置了三個(gè)transactionManager
* ===========================================================================================================
* @Bean("formTransactionManager")
* public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {
*     return new JpaTransactionManager(Objects.requireNonNull(entityManagerFactory(builder).getObject()));
* }
*=============================================================================================================
* @Bean("fileTransactionManager")
* public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {
*     return new JpaTransactionManager(Objects.requireNonNull(entityManagerFactory(builder).getObject()));
* }
* ============================================================================================================
* @Primary
* @Bean("userTransactionManager")
* public PlatformTransactionManager transactionManager(EntityManagerFactoryBuilder builder) {
*     return new JpaTransactionManager(Objects.requireNonNull(entityManagerFactory(builder).getObject()));
* }
* =============================================================================================================
*
* 那么在使用@Transactional的時(shí)候需要指定transactionManager
* @Transactional("formTransactionManager")

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@EnableTransactionManagement // 開啟事務(wù)的支持

可以訪問(wèn)下druid監(jiān)控相關(guān)數(shù)據(jù):

http://localhost:9999/druid/

輸入上面的賬號(hào)和密碼:? 可以查看不同的選項(xiàng)卡,能幫助我們排查一些數(shù)據(jù)庫(kù)相關(guān)問(wèn)題