我想制作一个简单的Spring应用程序。我需要的是一个仅对数据库进行一些查询的应用程序。现在,我才刚刚开始使用Spring Boot,并想以此来达到目的。我只知道Spring Boot在理论上是如何工作的。
所以我有我的pom.xml,其中有2个启动器。无效的spring-boot-starter和spring-boot-starter-data-jdbc。
这是我的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>SpringBootTest</groupId>
<artifactId>sbt</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.2.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
</dependencies>
<!-- Package as an executable jar -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
然后我有我的应用程序类。此类在树的头部,因此在这里我放置了@ComponentScan。这里我需要自动装配数据源,因为我现在想保持简单。
有我的代码:
@ComponentScan
public class App {
@Autowired
DataSource dataSource;
public static void main (String... args) {
SpringApplication.run(App.class, args);
}
}
然后我有我的AppConfig类,可以在其中创建DataSource Bean。就是这样:
@Configuration
public class AppConfig {
@Bean
DataSource dataSource(){
return DataSourceBuilder.create().build();
}
}
发生的一件奇怪的事情是,当我启动应用程序时,我在其他不需要的启动器上收到了FileNotFoundException异常消息,例如集成,Web,安全性等。
这是StackTrace:
2019-01-26 17:18:26.570 WARN 16676 --- [ main] s.c.a.AnnotationConfigApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration$IntegrationComponentScanConfiguration]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/integration/config/IntegrationComponentScanRegistrar.class] cannot be opened because it does not exist
2019-01-26 17:18:26.589 INFO 16676 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-01-26 17:18:26.594 ERROR 16676 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration$IntegrationComponentScanConfiguration]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/integration/config/IntegrationComponentScanRegistrar.class] cannot be opened because it does not exist
at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:599) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:302) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:242) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:191) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:295) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:242) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:199) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:167) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:315) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:691) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:528) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at App.main(App.java:15) [classes/:na]
Caused by: java.io.FileNotFoundException: class path resource [org/springframework/integration/config/IntegrationComponentScanRegistrar.class] cannot be opened because it does not exist
at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:180) ~[spring-core-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:51) ~[spring-core-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:103) ~[spring-core-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:88) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:75) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:81) ~[spring-core-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.asSourceClass(ConfigurationClassParser.java:685) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser$SourceClass.getSuperClass(ConfigurationClassParser.java:998) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:332) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:242) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:589) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
... 19 common frames omitted
我做错了什么?
答案 0 :(得分:-1)
您的方法正确,这是您的缩短代码。我很懒于发布两个代码段。为您的应用程序上下文创建包装器类也很明智:)
package longnguyen.de;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import javax.sql.DataSource;
@SpringBootApplication
public class App {
private final DataSource dataSource;
@Autowired
public App(final DataSource dataSource) {
this.dataSource = dataSource;
}
public static void main (String... args) {
SpringApplication.run(App.class, args);
}
@Bean
DataSource dataSource(){
return DataSourceBuilder.create().build();
}
}
此外,我添加了更多依赖项。
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<version>2.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
<version>2.1.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.1.4.RELEASE</version>
</dependency>
</dependencies>