我已经为此投入了好几天，并且 - 尽管我学到了很多东西 - 开始感到绝望。
我已经尝试了关于这个优秀问题的所有建议:
No Persistence provider for EntityManager named
我曾经使用无处不在的 HibernateUtil 类来完成这项工作，但在这里被告知要改用普通的 JPA 样式:
Spring RESTful controller method improvement suggestions
不幸的是，我无法让 bean 注入(inject)在 spring-boot 中正常工作。这是我的尝试:
Spring JPA (Hibernate) No qualifying bean of type: javax.persistence.EntityManagerFactory
在这条道路上经过大量工作后，我最终得到了一个空实体管理器。我发现了这个并开始认为它不起作用:
Using JPA2 in Tomcat 6: @PersitenceContext doesn't work, EntityManager is null
在我看来，EntityManagerFactory 在 spring-boot 创建的任何上下文中绝对应该是一个 bean，但是......无论如何。我认为至少这会起作用:
应用启动:
@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
Controller :
@Controller
public class GetController {
private static final String PERSISTENCE_UNIT_NAME = "cpJpaPu";
@RequestMapping(value = "/user", method = RequestMethod.GET)
public @ResponseBody User getUser(@RequestParam(value="id", required=true) int id) {
User user = null;
EntityManagerFactory emf = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager em = emf.createEntityManager();
UserDAO userDao = new UserDAO();
userDao.setEntityManager(em);
user = userDao.load(id);
return user;
}
}
道:
public class UserDAO {
public EntityManager entityManager;
public void setEntityManager(EntityManager entityManager) {
this.entityManager = entityManager;
}
public EntityManager getEntityManager() {
return entityManager;
}
public void insert(User user) {
entityManager.persist(user);
}
public User load(int id) {
return entityManager.find(User.class, id);
}
}
/src/main/resources/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="cpJpaPu" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.mydomain.User</class>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
<property name="hibernate.connection.driver_class" value="org.postgresql.Driver"/>
<property name="hibernate.show_sql" value="false"/>
<property name="hibernate.connection.username" value="user"/>
<property name="hibernate.connection.password" value=""/>
<property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/mydb"/>
</properties>
</persistence-unit>
</persistence>
它不起作用:
javax.persistence.PersistenceException: No Persistence provider for EntityManager named cpJpaPu
javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:61)
javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
com.mydomain.GetController.getUser(GetController.java:25)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:947)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:878)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:946)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:837)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:822)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
--- 添加信息 ---
POM:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mygroup</groupId>
<artifactId>myartifact</artifactId>
<version>0.1.0</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>0.5.0.M6</version>
</parent>
<dependencies>
<!-- Spring framework -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- Hibernate -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.0.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<!-- Must override version or face stack traces -->
<version>4.3.0.Final</version>
</dependency>
<!-- Spring ORM, works with Hibernate -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
</dependency>
<!-- Spring implementation of Jackson for RESTful JSON -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
<!-- JDBC -->
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.1-901.jdbc4</version>
</dependency>
<!-- Logging -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</dependency>
<!-- Prevent logging conflicts -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<properties>
<start-class>com.cloudfordev.controlpanel.Application</start-class>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/libs-snapshot</url>
<snapshots><enabled>true</enabled></snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-snapshots</id>
<url>http://repo.spring.io/libs-snapshot</url>
<snapshots><enabled>true</enabled></snapshots>
</pluginRepository>
</pluginRepositories>
</project>
最佳答案
spring boot默认不读取persistence.xml文件，这里查看文档
https://docs.spring.io/spring-boot/docs/current/reference/html/howto-data-access.html
因此，如果您想继续使用 persistence.xml 文件，只需将以下代码添加到您的 AppConfig 类中
@Bean
public LocalEntityManagerFactoryBean entityManagerFactory(){
LocalEntityManagerFactoryBean factoryBean = new LocalEntityManagerFactoryBean();
factoryBean.setPersistenceUnitName("cpJpaPu");
return factoryBean;
}
关于java - Spring-boot:不能使用持久性，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20848485/