在springboot中找不到的bean类型的必填字段

Question

我遇到了一个非常常见的Springboot错误，但是我无法找出原因。可能是因为我的课程是不同的模块。因此，我尝试将@ComponentScan包含在主类中，但是没有用。请问。

错误：

2020-08-18 15:16:12.543  WARN 28852 --- [  restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'applicationRun': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'provRecordsProcess': Unsatisfied dependency expressed through field 'dbConfig'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.emer.payeng.config.DataSourceDbConfig' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
2020-08-18 15:16:12.546  INFO 28852 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2020-08-18 15:16:12.564  INFO 28852 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-08-18 15:16:12.743 ERROR 28852 --- [  restartedMain] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Field dbConfig in com.emer.payeng.service.ProvRecordsProcess required a bean of type 'com.emer.payeng.config.DataSourceDbConfig' that could not be found.


Action:

Consider defining a bean of type 'com.emer.payeng.config.DataSourceDbConfig' in your configuration.

我的项目结构：

 src/main/java
  > com.eme.payeng
    > ApplicationRun.java
  > com.eme.payeng.pojo
    > ProvMappingPOJO.java
  > com.emer.payeng.service
    > ProvRecordProcess.java
    > ProvRecordMapper.java
  > com.emer.payeng.config
    > DataSourceDbConfig.java
  

ApplicationRun.java：

    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import com.emer.payeng.service.ProvRecordsProcess;

@SpringBootApplication
public class ApplicationRun {
    
    @Autowired
    static ProviderRecordsProcess provRecords;
    
    
    public ApplicationRun(ProviderRecordsProcess provRecords){
        ApplicationRun.provRecords = provRecords    ;
    }
    

    public static void main(String[] args) {
        SpringApplication.run(ApplicationRun.class, args);
        
        provRecords.dbFetchProvRecords();
    }

}

ProvRecordProcess.java

package com.emer.payeng.service;

import java.util.List;

import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import com.emer.payeng.pojo.ProvMappingPOJO;
import com.emer.payeng.config.DataSourceDbConfig;

@Component
public class ProvRecordsProcess {
    
    @Autowired
    DataSourceDbConfig dbConfig;
    DataSource dataSource;
    
    
    public void dbFetchProvRecords() {
        
        dataSource = dbConfig.dataSource();
        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
        
        // code to fetch records from tables //
        }
        
    }
}

DataSourceDbConfig.java

package com.emer.payeng.config;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;

import oracle.jdbc.pool.OracleDataSource;
import java.sql.SQLException;
import javax.sql.DataSource;

@Component
@Configuration
@ConfigurationProperties("spring.datasource")

public class DataSourceDbConfig {
    
    @Value("${spring.datasource.url}")
    private String dbUrl;
        
    @Value("${spring.datasource.username}")
    private String dbUser;
        
    @Value("${spring.datasource.secure}")
    private String dbPasswrd;
    
    @Bean
    public DataSource dataSource() {
        
        OracleDataSource dataSource = null;
        try {
            dataSource = new OracleDataSource();
            dataSource.setUser(dbUser);
            dataSource.setPassword(dbPasswrd);
            dataSource.setURL(dbUrl);
            
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        return dataSource;
    }

}