我试图在 Spring Boot Maven 项目中使用 KieSession 的持久性功能来实现 Drools。已关注 this documentation以便实现。能够在普通的 Java 应用程序中执行此操作，但在尝试在 Spring Boot 应用程序中执行此操作时出现异常。
下面是实现。
项目结构
配置类
@Configuration
public class PersistentDroolConfig {
public static Long KIE_SESSION_ID;
private final KieServices kieServices = KieServices.Factory.get();
@Bean
public KieSession kieSession() {
KieSession kieSession = kieServices.getStoreServices().newKieSession(getKieBase(), null, getEnv());
PersistentDroolConfig.KIE_SESSION_ID = kieSession.getIdentifier();
return kieSession;
}
public KieServices getKieServices() {
initDataSource();
return kieServices;
}
public KieBase getKieBase() {
KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
kieFileSystem.write(ResourceFactory.newClassPathResource("rules/rules.drl"));
final KieRepository kieRepository = kieServices.getRepository();
kieRepository.addKieModule(kieRepository::getDefaultReleaseId);
KieBuilder kb = kieServices.newKieBuilder(kieFileSystem);
kb.buildAll();
KieModule kieModule = kb.getKieModule();
KieContainer kieContainer = kieServices.newKieContainer(kieModule.getReleaseId());
return kieContainer.getKieBase();
}
public Environment getEnv() {
Environment env = kieServices.newEnvironment();
env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, Persistence.createEntityManagerFactory("org.drools.persistence.jpa"));
env.set(EnvironmentName.TRANSACTION_MANAGER, TransactionManagerServices.getTransactionManager());
return env;
}
private void initDataSource() {
PoolingDataSource ds = new PoolingDataSource();
ds.setUniqueName("jdbc/BitronixJTADataSource");
ds.setClassName("com.mysql.cj.jdbc.MysqlXADataSource");
ds.setMaxPoolSize(3);
ds.setAllowLocalTransactions(true);
ds.getDriverProperties().put("user", "root");
ds.getDriverProperties().put("password", "1234");
ds.getDriverProperties().put("URL", "jdbc:mysql://localhost:3306/drool_demo");
ds.init();
}
}
Controller 类
@RestController
public class OfferController {
@Autowired
private KieSession kieSession;
@GetMapping("/order/{card-type}/{price}")
public Order order(@PathVariable("card-type") String cardType, @PathVariable int price) {
Order order = new Order(cardType, price);
kieSession.insert(order);
kieSession.fireAllRules();
return order;
}
}
事实类
public class Order implements Serializable {
private String name;
private String cardType;
private int discount;
private int price;
public Order(String cardType, int price) {
this.cardType = cardType;
this.price = price;
}
// setters and getters
// toString()
}
persistence.xml
<persistence version="2.0"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd
http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_2_0.xsd"
xmlns:orm="http://java.sun.com/xml/ns/persistence/orm"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="org.drools.persistence.jpa"
transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>jdbc/BitronixJTADataSource</jta-data-source>
<class>org.drools.persistence.info.SessionInfo</class>
<class>org.drools.persistence.info.WorkItemInfo</class>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
<property name="hibernate.max_fetch_depth" value="3" />
<property name="hibernate.hbm2ddl.auto" value="create" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.BTMTransactionManagerLookup" />
</properties>
</persistence-unit>
</persistence>
pom.xml文件中包含的依赖项如下:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.github.marcus-nl.btm</groupId>
<artifactId>btm</artifactId>
<version>3.0.0-mk1</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-decisiontables</artifactId>
<version>${drools-version}</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-core</artifactId>
<version>${drools-version}</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-compiler</artifactId>
<version>${drools-version}</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-persistence-jpa</artifactId>
<version>${drools-version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
错误堆栈跟踪:
Caused by: org.hibernate.engine.jndi.JndiException: Unable to lookup JNDI name [jdbc/BitronixJTADataSource]
Caused by: javax.naming.NameNotFoundException: unable to find a bound object at name 'jdbc/BitronixJTADataSource'
该项目也可以在 this repository 中找到。 .
更新1:
实现@jccampanero的答案后，我有一个更新的堆栈跟踪:
Caused by: org.hibernate.HibernateException: Unable to perform isolated work
Caused by: java.sql.SQLSyntaxErrorException: Table 'drool_demo.sessioninfo_id_seq' doesn't exist
更新2:
经过进一步挖掘，我发现 Drools 由于某些语法错误而没有制作必要的表格。由于 Stackoverflow 有文本限制，因此此处仅发布重要的异常消息。这是:
Hibernate: drop table if exists SessionInfo
Hibernate: drop table if exists WorkItemInfo
Hibernate: create table SessionInfo (id bigint not null auto_increment, lastModificationDate datetime, rulesByteArray longblob, startDate datetime, OPTLOCK integer, primary key (id)) type=MyISAM
2020-10-09 23:49:59.554 WARN 11376 --- [ main] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL "create table SessionInfo (id bigint not null auto_increment, lastModificationDate datetime, rulesByteArray longblob, startDate datetime, OPTLOCK integer, primary key (id)) type=MyISAM" via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "create table SessionInfo (id bigint not null auto_increment, lastModificationDate datetime, rulesByteArray longblob, startDate datetime, OPTLOCK integer, primary key (id)) type=MyISAM" via JDBC Statement
Caused by: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'type=MyISAM' at line 1
Hibernate: create table WorkItemInfo (workItemId bigint not null auto_increment, creationDate datetime, name varchar(255), processInstanceId bigint not null, state bigint not null, OPTLOCK integer, workItemByteArray longblob, primary key (workItemId)) type=MyISAM
2020-10-09 23:49:59.556 WARN 11376 --- [ main] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL "create table WorkItemInfo (workItemId bigint not null auto_increment, creationDate datetime, name varchar(255), processInstanceId bigint not null, state bigint not null, OPTLOCK integer, workItemByteArray longblob, primary key (workItemId)) type=MyISAM" via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "create table WorkItemInfo (workItemId bigint not null auto_increment, creationDate datetime, name varchar(255), processInstanceId bigint not null, state bigint not null, OPTLOCK integer, workItemByteArray longblob, primary key (workItemId)) type=MyISAM" via JDBC Statement
Caused by: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'type=MyISAM' at line 1
最佳答案
我认为您的配置有问题。永远不会调用 PersistentDroolConfig 类的 getKieServices 方法，因此，初始化数据源的方法 initDataSource 也不会被调用。
也许您可以尝试修改您的PersistentDroolConfig，如下所示:
@Configuration
public class PersistentDroolConfig {
public static Long KIE_SESSION_ID;
private KieServices kieServices;
@PostContruct
private void init() {
this.initDataSource();
this.kieServices = KieServices.Factory.get();
}
@Bean
public KieSession kieSession() {
KieSession kieSession;
if (KIE_SESSION_ID == null) {
kieSession = createNewKieSession();
KIE_SESSION_ID = kieSession.getIdentifier();
return kieSession;
} else {
kieSession = getPersistentKieSession();
KIE_SESSION_ID = kieSession.getIdentifier();
return kieSession;
}
}
public KieBase getKieBase() {
KieFileSystem kieFileSystem = kieServices.newKieFileSystem();
kieFileSystem.write(ResourceFactory.newClassPathResource("rules/rules.drl"));
final KieRepository kieRepository = kieServices.getRepository();
kieRepository.addKieModule(new KieModule() {
@Override
public ReleaseId getReleaseId() {
return kieRepository.getDefaultReleaseId();
}
});
KieBuilder kb = kieServices.newKieBuilder(kieFileSystem);
kb.buildAll();
KieModule kieModule = kb.getKieModule();
KieContainer kieContainer = kieServices.newKieContainer(kieModule.getReleaseId());
KieBase kieBase = kieContainer.getKieBase();
return kieBase;
}
public Environment getEnv() {
Environment env = kieServices.newEnvironment();
env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, Persistence.createEntityManagerFactory("org.drools.persistence.jpa"));
env.set(EnvironmentName.TRANSACTION_MANAGER, TransactionManagerServices.getTransactionManager());
return env;
}
private KieSession createNewKieSession() {
KieSession kieSession = kieServices.getStoreServices().newKieSession(getKieBase(), null, getEnv());
PersistentDroolConfig.KIE_SESSION_ID = kieSession.getIdentifier();
return kieSession;
}
private KieSession getPersistentKieSession() {
return kieServices.getStoreServices().loadKieSession(KIE_SESSION_ID, getKieBase(), null, getEnv());
}
private void initDataSource() {
PoolingDataSource ds = new PoolingDataSource();
ds.setUniqueName("jdbc/BitronixJTADataSource");
ds.setClassName("com.mysql.cj.jdbc.MysqlXADataSource");
ds.setMaxPoolSize(3);
ds.setAllowLocalTransactions(true);
ds.getDriverProperties().put("user", "root");
ds.getDriverProperties().put("password", "1234");
ds.getDriverProperties().put("URL", "jdbc:mysql://localhost:3306/drool_demo");
ds.init();
}
}
更新
正如不同评论中所述，进行这些更改后，出现了与用于生成实体 SessionInfo 的字段 id 值的 SESSIONINFO_ID_SEQ 序列相关的问题.
问题似乎与使用的 Hibernate 和 MySQL 版本有关。
要解决该问题，需要对 persistence.xml 文件进行一些更改。
首先，应包含以下属性:
<property name="hibernate.id.new_generator_mappings" value="false" />
它经常用于 Drools 示例和 test cases 中。请参阅 this 伟大的 Vlad Mihalcea 文章以获取深入的解释。
包含此配置属性会产生与所使用的 MySQL 方言相关的新问题。应改为:
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
使用此配置，应用程序应该可以顺利运行。
关于java - 无法在Spring Boot中实现Drools KieSession持久化，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/64221767/