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您应该将依赖项用于spring-boot-starter-data-jpa
<dependency>
<groupID>org.springframework.boot</groupID>
<artifactID>spring-boot-starter-data-jpa</artifactID>
</dependency>
要使用持久性xml,您应该按照文档中的定义定义一个bean。
http://docs.spring.io/spring-boot/docs/current/reference/html/howto-data- access.HTML#howto-use-Traditional-persistence- xml
或者,您可以完全跳过persistence.xml,并在application.propertIEs文件中定义连接属性。
引用文档
spring.datasource.url=jdbc:MysqL://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.Mysql.jdbc.Driver
http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features- sql.HTML#boot-features-connect-to-production- database
(更改驱动程序和其他数据以匹配您的环境)
祝好运!
在我的J2EE应用程序中,我尝试使用spring-
boot和JPA技术,并将Entitymanager注入DAO层。但是,我遇到了一些问题&Hellip;用户CRUD的存储库:
@Repository
public class UserRepositoryImpl implements UserRepository {
@PersistenceContext(unitName = "data")
private Entitymanager entitymanager;
// and crud methods
}
我的spring-boot应用程序类:
@SpringBootApplication
public class App {
public static void main(String [] args) {
SpringApplication.run(App.class,args);
}
}
最后是我的persistence.xml,位于src / main / resources / META-INF文件夹中:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLscheR_202_11845@a-instance"
xsi:scheR_202_11845@aLOCATIOn="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="data" transaction-type="resourcE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<class>com.example.domain.User</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.connection.autocommit" value="false" />
<property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect" />
<property name="hibernate.c3p0.min_size" value="4" />
<property name="hibernate.c3p0.max_size" value="128" />
<property name="javax.persistence.jdbc.url" value="jdbc:sqlserver://localhost:1433;databasename=qwerty;sendStringParametersAsUnicode=false" />
<property name="javax.persistence.jdbc.user" value="sa" />
<property name="javax.persistence.jdbc.driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
<property name="javax.persistence.jdbc.password" value="" />
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.show_sql" value="false" />
</properties>
</persistence-unit>
因此,当我尝试使用此注入的entitymanager时,会收到NullPointerException。注入其他@Autowired字段没有任何问题。此代码有什么问题?我需要一些额外的配置吗?我是一个初学者(甚至不是初级开发人员),而且对于Spring-
boot是什么以及如何配置它(例如xml文件中的Spring)确实有一些误解。如果由于注入EM而需要这种xml配置,请说明如何执行。
upd2。依存关系
<dependencies>
<!-- logger -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
</dependency>
<!-- db -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-c3p0</artifactId>
</dependency>
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
</dependency>
<dependency>
<groupId>com.microsoft</groupId>
<artifactId>sqljdbc4</artifactId>
</dependency>
<dependency>
<groupId>org.quartz-scheduler</groupId>
<artifactId>quartz</artifactId>
<version>2.2.1</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-Annotations</artifactId>
<version>2.5.3</version>
</dependency>
<!-- csv -->
<dependency>
<groupId>com.opencsv</groupId>
<artifactId>opencsv</artifactId>
<version>3.3</version>
</dependency>
<!-- spring-boot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>1.2.4.RELEASE</version>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j</artifactId>
<version>1.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.1.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>1.2.4.RELEASE</version>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
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