我知道JPA 2是一个规范,Hibernate是ORM的工具.另外,我知道Hibernate比JPA 2有更多的功能.但从实际的角度来看,真正的区别是什么？
我有使用iBatis的经验,现在我正在尝试学习Hibernate或JPA2.我选了Pro JPA2书,它一直指的是"JPA提供者".例如:
如果您认为某个功能应该标准化,那么您应该说出来并向您的JPA提供商索取
这让我很困惑,所以我有几个问题:
尝试将JPA添加到Spring Boot程序时遇到问题.一切正常,直到我将下面的内容添加到我的pom.xml中(我还没有添加任何与JPA Hibernate相关的代码)
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
运行创建的jar文件时出现以下错误.用mvn clean包编译返回没有错误.
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078) ~[spring-context-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.12.RELEASE.jar!/:4.3.12.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.8.RELEASE.jar!/:1.5.8.RELEASE]
at hello.App.main(App.java:19) [classes!/:0.1.0] …我正在开发Spring Boot应用程序,并在启动服务器时遇到此错误.我不确定我是否错误地定义了任何注释或缺少任何依赖项.任何帮助,将不胜感激.
主要课程:
@SpringBootApplication
public class FantasyManagerApplication {
public static void main(String[] args) {
SpringApplication.run(FantasyManagerApplication.class, args);
}
}
LeagueService.java:
@Service
public class LeagueService {
@Autowired
private LeagueRepository leagueRepository;
@Autowired
private PlayerRepository playerRepository;
@Autowired
private TeamRepository teamRepository;
/**
* Returns a list of all the leagues in the database
* @return List<League>
*/
public List<League> getAllLeagues(){
List<League> leagues = new ArrayList<>();
leagueRepository.findAll()
.forEach(leagues::add);
return leagues;
}
/**
* Find details for a particular League
* @param leagueId
* @return League
*/ …我最近在我的网站上添加了SSL,可以通过https访问.现在,当我的java应用程序尝试向我的网站发出请求并使用缓冲读取器从中读取它时,它会生成此堆栈跟踪
我没有使用自签名证书,证书来自Namecheap,他使用COMODO SSL作为CA来签署我的证书.即时通讯使用java 8
javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at sun.security.ssl.Handshaker.activate(Handshaker.java:503)
at sun.security.ssl.SSLSocketImpl.kickstartHandshake(SSLSocketImpl.java:1482)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1351)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
我的代码非常基本,只是尝试使用缓冲读取器在我的网站上阅读页面
private void populateDataList() {
try {
URL url = new URL("https://myURL.com/Data/Data.txt");
URLConnection con = url.openConnection();
con.setRequestProperty("Connection", "close");
con.setDoInput(true);
con.setUseCaches(false);
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line;
int i = 0;
while((line = in.readLine()) != null) {
this.url.add(i, line);
i++;
}
} catch (Exception e) {
e.printStackTrace();
}
}
我已经尝试将我的SSL证书添加到JVM的密钥库中,我甚至尝试使用此代码接受每个证书(这证明了我知道的SSL的目的)
private …当我尝试使用 hibernate 和 MySql 运行我的 spring-boot 项目时，出现以下错误。
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-07-10 15:15:32.474 ERROR 12112 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: com.sliit.af.model.Course
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1778) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.8.RELEASE.jar:5.1.8.RELEASE]
at …当我尝试编译项目时出现错误
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-02-11 15:21:24.256 ERROR 14192 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Unsatisfied dependency expressed through method 'entityManagerFactory' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'entityManagerFactoryBuilder' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Unsatisfied dependency expressed through method 'entityManagerFactoryBuilder' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with …