关于 JPA Spring Boot 应用程序的问题

huangapple
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英文:

Problems with Jpa Spring Boot application

问题

  1. 我尝试运行时出现了很多错误，我无法理解发生了什么。
  2. 以下是其中一些错误：
  4. 出现了意外错误（类型=内部服务器错误，状态=500）。
  5. 无法提取ResultSet；SQL [n/a]；嵌套异常是org.hibernate.exception.SQLGrammarException：无法提取ResultSet
  6. org.springframework.dao.InvalidDataAccessResourceUsageException：无法提取ResultSet；SQL [n/a]；嵌套异常是org.hibernate.exception.SQLGrammarException：无法提取ResultSet
  7. 	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:279)
  8. 	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:253)
  9. 	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:527)
  10. 	at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:61)
  11. 	at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:242)
  12. 	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:153)
  13. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  14. 	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:144)
  15. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  16. 	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$ExposeRepositoryInvocationInterceptor.invoke(CrudMethodMetadataPostProcessor.java:364)
  17. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  18. 	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
  19. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  20. 	at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
  21. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  22. 	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
  23. 	at com.sun.proxy.$Proxy83.findAll(Unknown Source)
  25. 我是按照一个指南完成的，但这个指南相当旧了，也许我应该更改JPA依赖，或者以不同的方式创建我的数据库？
  26. 这是关于JPA的第二课程的存储库
  27. https://github.com/drucoder/sweater/tree/JPA_Postgres
  29. 这是我的application.properties：
  30. spring.datasource.url=jdbc:postgresql://localhost/sweater
  31. spring.datasource.username=postgres
  32. spring.datasource.password=1506
  33. spring.jpa.generate-ddl-auto=update
  35. 我通过pgadmin创建了名为sweater的空数据库。
  36. 此外，我的IDE向我显示单词Postgresql中有拼写错误。
  37. 这是我的pom.xml：
  38. （以下是您的pom.xml代码，已省略）
  40. 这是我的Controller：
  41. （以下是您的Controller代码，已省略）
英文:

There are a lot of errors when I try to run it, I cant understand
exactly what happened.
here it is some of them:

  1. There was an unexpected error (type=Internal Server Error, status=500).
  2. could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet
  3. org.springframework.dao.InvalidDataAccessResourceUsageException: could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet
  4. 	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:279)
  5. 	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:253)
  6. 	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:527)
  7. 	at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:61)
  8. 	at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:242)
  9. 	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:153)
  10. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  11. 	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:144)
  12. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  13. 	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$ExposeRepositoryInvocationInterceptor.invoke(CrudMethodMetadataPostProcessor.java:364)
  14. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  15. 	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
  16. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  17. 	at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
  18. 	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
  19. 	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
  20. 	at com.sun.proxy.$Proxy83.findAll(Unknown Source)

I did it by one guide, but this guide is quite old, maybe I should change the JPA dependencies, or create my database differently?
here it is the repository of the second lesson about JPA
https://github.com/drucoder/sweater/tree/JPA_Postgres

This is my application.properties:

  1. spring.datasource.username=postgres
  2. spring.datasource.password=1506
  3. spring.jpa.generate-ddl-auto=update

I create my empty database sweater by pgadmin.
Also, my ide shows me that there is Typo in word Postgresql.
This is my pom.xml:

  1. <parent>
  2.         <groupId>org.springframework.boot</groupId>
  3.         <artifactId>spring-boot-starter-parent</artifactId>
  4.         <version>2.1.7.RELEASE</version>
  5.     </parent>
  7.     <dependencies>
  8.     <dependency>
  9.         <groupId>org.springframework.boot</groupId>
  10.         <artifactId>spring-boot-starter-web</artifactId>
  11.     </dependency>
  13.     <dependency>
  14.         <groupId>org.springframework.boot</groupId>
  15.         <artifactId>spring-boot-starter-mustache</artifactId>
  16.     </dependency>
  18.         <dependency>
  19.             <groupId>org.springframework.boot</groupId>
  20.             <artifactId>spring-boot-starter-data-jpa</artifactId>
  21.         </dependency>
  23.         <dependency>
  24.             <groupId>org.postgresql</groupId>
  25.             <artifactId>postgresql</artifactId>
  26.             <scope>runtime</scope>
  27.         </dependency>
  29.         <dependency>
  30.             <groupId>org.springframework.boot</groupId>
  31.             <artifactId>spring-boot-devtools</artifactId>
  32.             <optional>true</optional>
  33.         </dependency>
  34.     </dependencies>
  36.     <properties>
  37.         <java.version>1.8</java.version>
  38.     </properties>
  40.     <build>
  41.         <plugins>
  42.             <plugin>
  43.                 <groupId>org.springframework.boot</groupId>
  44.                 <artifactId>spring-boot-maven-plugin</artifactId>
  45.             </plugin>
  46.         </plugins>
  47.     </build>
  48. </project>

And this is my Controller:

  1. @Controller
  2. public class GreetingController {
  3.     @Autowired
  4.     private MessageRepo messageRepo;
  5.     @GetMapping("/greeting")
  6.     public String greeting(
  7.             @RequestParam(name="name", required=false, defaultValue="World") String name,
  8.             Map<String, Object> model
  9.     ) {
  10.         model.put("name", name);
  11.         return "greeting";
  12.     }
  14.     @GetMapping
  15.     public String main(Map<String, Object> model) {
  16.        Iterable<Message> messages = messageRepo.findAll();
  17.         model.put("messages", messages);
  18.         return "main";
  19.     }
  21.     @PostMapping
  22.     public String add(@RequestParam String text, @RequestParam String tag, Map<String, Object> model){
  23.        Message message = new Message(text,tag);
  24.        messageRepo.save(message);
  25.         Iterable<Message> messages = messageRepo.findAll();
  26.         model.put("messages", messages);
  27.         return "main";
  28.     }
  31.     @PostMapping("filter")
  32.     public String filter(@RequestParam String filter, Map<String, Object> model) {
  33.         Iterable<Message> messages;
  35.         if (filter != null && !filter.isEmpty()) {
  36.             messages = messageRepo.findByTag(filter);
  37.         } else {
  38.             messages = messageRepo.findAll();
  39.         }
  41.         model.put("messages", messages);
  43.         return "main";
  44.     }
  45. }

答案1

得分: 1

将你的application.properties文件从以下内容进行修改：

  1. spring.datasource.username=postgres
  2. spring.datasource.password=1506
  3. spring.jpa.generate-ddl-auto=update

修改为：

  1. spring.datasource.username=postgres
  2. spring.datasource.password=1506
  3. spring.jpa.generate-ddl-auto=update
  4. spring.datasource.url=jdbc:postgresql://localhost/{你的数据库名称}
英文:

Change your application.properties from

  1.  spring.datasource.username=postgres
  2.  spring.datasource.password=1506
  3.  spring.jpa.generate-ddl-auto=update

to

  1.  spring.datasource.username=postgres
  2.  spring.datasource.password=1506
  3.  spring.jpa.generate-ddl-auto=update     
  4.  spring.datasource.url=jdbc:postgresql://localhost/{your db name}

huangapple
  • 本文由 发表于 2020年6月29日 15:35:02
  • 转载请务必保留本文链接：https://java.coder-hub.com/62633296.html
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