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java - spring jpa - 必须存在至少一个 JPA 元模型*

转载 作者:搜寻专家 更新时间:2023-11-01 01:20:26 24 4
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有人知道为什么它不起作用吗?

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
06/04/2017 14:11:24.732 ERROR [main] - org.springframework.boot.SpringApplication: Application startup failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: At least one JPA metamodel must be present!
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:742)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:314)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151)
at com.cadit.web.WebApplicationAware.main(WebApplicationAware.java:19)
Caused by: java.lang.IllegalArgumentException: At least one JPA metamodel must be present!
at org.springframework.util.Assert.notEmpty(Assert.java:277)
at org.springframework.data.jpa.mapping.JpaMetamodelMappingContext.<init>(JpaMetamodelMappingContext.java:52)
at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:71)
at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:26)
at org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet(AbstractFactoryBean.java:134)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
... 16 common frames omitted

我在 com.cadit.entities 中定义了实体:

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="TEST")
public class GenericBeans implements BeanType, IEntity<Long> {

/**
*
*/
private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name = "TEST_PAID")
protected Long id;

@Column(name = "SOCIETA")
private String SocietaCod;
@Column(name = "CONTO_INTERMEDIARIO")
private String contoInt;
@Column(name = "TIPO_OPERAZIONE")
private String tipoOpe;


public GenericBeans(String societaCod, String contoInt, String tipoOpe) {
SocietaCod = societaCod;
this.contoInt = contoInt;
this.tipoOpe = tipoOpe;
}


public GenericBeans() {

}




public String getSocietaCod() {
return SocietaCod;
}


public void setSocietaCod(String societaCod) {
SocietaCod = societaCod;
}


public String getContoInt() {
return contoInt;
}


public void setContoInt(String contoInt) {
this.contoInt = contoInt;
}


public String getTipoOpe() {
return tipoOpe;
}


public void setTipoOpe(String tipoOpe) {
this.tipoOpe = tipoOpe;
}


@Override
public String toString() {
return "CSV [SocietaCod=" + SocietaCod + ", contoInt=" + contoInt + ", tipoOpe=" + tipoOpe + "]";
}


@Override
public Long getId() {
return this.id;
}


@Override
public void setId(Long id) {
this.id=id;
}

}

我为 spring 定义了我的 datasource 入口定义:

import org.apache.log4j.Logger;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@ComponentScan
@EntityScan("com.cadit.entities")
//@EnableJpaRepositories("com.cadit.entities")
@EnableTransactionManagement
@PropertySource("classpath:db-config.properties")
public class DbAutoConfiguration {


static final Logger logger = Logger.getLogger(DbAutoConfiguration.class);

public DbAutoConfiguration() {

}


@Bean
@ConfigurationProperties(prefix = "spring.datasource")
public DataSource dataSource(){
//DataSource ds =new EmbeddedDatabaseBuilder().addScript("classpath:sql/schema.sql").addScript("classpath:testdb/data.sql").build();
DataSourceBuilder ds = DataSourceBuilder.create();
logger.info("dataSource = " + ds);
return ds.build();

}
}

我的 db-config.properties 是:

spring.jpa.hibernate.ddl-auto: validate
spring.jpa.hibernate.naming_strategy: org.hibernate.cfg.ImprovedNamingStrategy
#spring.jpa.database: SQL
spring.jpa.show-sql: true

spring.datasource.driverClassName=net.sourceforge.jtds.jdbc.Driver
spring.datasource.url=jdbc:jtds:sqlserver://localhost:1433;databaseName=example
spring.datasource.username=xxx
spring.datasource.password=xxx

IEntity 是:

public interface IEntity <I extends Serializable> extends Serializable{

/**
* Property rappresenta la primary key.
*/
String P_ID = "id";

/**
* restituisce la primary key
* @return
*/
I getId();

/**
* imposta la primary key
* @param id
*/
void setId(I id);
}

我尝试使用 spring 的 CrudRepository 接口(interface)将 CSV 文件写入数据库:

import java.io.File;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.repository.CrudRepository;

import com.cadit.entities.GenericBeans;
import com.csvreader.CsvReader;

public class CsvReaders {

static final Logger logger = Logger.getLogger(CsvReader.class);

@Autowired
public CrudRepository<GenericBeans,Long> _entitymanager;

public List loadDataFromCsv(String fileName) {
try {

File file = new ClassPathResource(fileName).getFile();
CsvReader csv = new CsvReader(file.getAbsoluteFile().getPath(),';');
csv.readHeaders();
List l = new LinkedList();
GenericBeans b = new GenericBeans ();
while (csv.readRecord())
{
b.setSocietaCod(csv.get(0));
b.setContoInt(csv.get(1));
b.setTipoOpe(csv.get(2));
_entitymanager.save(b); //persist on db
l.add(b);
b = new GenericBeans();
}
b=null;
return l;
} catch (Exception e) {
logger.error("Error occurred while loading object list from file " + fileName, e);
return Collections.emptyList();
}
}


}

我不使用 main 类,而是使用扩展 SpringBootServletInitializer 的类,因为我想在独立的 tomcat 和 Tomcat 安装上运行它作为 WAR 应用程序

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;


@Configuration
@ComponentScan(basePackages={"com.cadit.entities","com.cadit.beans"})
@EnableAutoConfiguration
public class WebApplicationAware extends SpringBootServletInitializer {

private static Class<WebApplicationAware> applicationClass = WebApplicationAware.class;

public static void main(String[] args) {
SpringApplication.run(applicationClass, args);
}

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(applicationClass);
}




}

所有属性文件都在类路径资源中,因为它是一个 Maven 项目。

pom.xml:

<?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>org.springframework</groupId>
<artifactId>xxxx</artifactId>
<version>0.1.0</version>
<packaging>war</packaging>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
</parent>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.jayway.jsonpath</groupId>
<artifactId>json-path</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.11.1.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0.2</version>
</dependency>


<!-- altre dipendenze non spring -->
<!-- https://mvnrepository.com/artifact/net.sourceforge.javacsv/javacsv -->
<dependency>
<groupId>net.sourceforge.javacsv</groupId>
<artifactId>javacsv</artifactId>
<version>2.0</version>
</dependency>

<!-- per jpa solo se si usa il Tomcat embedded -->
<dependency>
<groupId>net.sourceforge.jtds</groupId>
<artifactId>jtds</artifactId>
<version>1.3.1</version>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
<version>2.1.1</version>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<!-- end -->


<!-- dipendenze logback -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>1.7.5</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.7</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.1.7</version>
</dependency>

<!-- fine dip logback -->

</dependencies>

<properties>
<start-class>hello.WebApplicationAware</start-class>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>


<build>

<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>

<repositories>
<repository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</pluginRepository>
</pluginRepositories>
</project>

有什么问题,为什么当我运行 WebApplicationAware 类时它找不到 JPA 实体?

最佳答案

Spring 没有找到任何 JPA 实体,因此没有创建 JPA 元模型,这就是您遇到异常的原因。

此问题的原因可能是您的类路径中的持久性 API 版本错误。

你正在使用

<dependency> 
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0.2</version>
</dependency>

但我很确定您的 spring 版本使用 persistence-api 版本 2。

难道您正在使用版本 1 中的 @Entity 注释?在运行时,sp​​ring 使用版本 2,这仅使用版本 2 中的@Entity 搜索实体!

移除依赖

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.11.1.RELEASE</version>
</dependency>

改为添加

  <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

这将为您提供正确版本的所有 JPA 依赖项。

关于java - spring jpa - 必须存在至少一个 JPA 元模型*,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43255169/

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