spring boot-jdbctemplate中的多个数据源为空

Question

#first DB
integration.datasource.jdbc-url=jdbc:sqlserver://localhost:port1/my_sample_schema1
integration.datasource.username=username
integration.datasource.password=password
integration.datasource.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver
integration.jpa.database-platform=org.hibernate.dialect.SQLServer2012Dialect
integration.jpa.show-sql=true


#second DB
spring.datasource.jdbc-url=jdbc:sqlserver://localhost:port2/my_sample_schema2
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver
spring.datasource.platform=org.hibernate.dialect.SQLServer2012Dialect
spring.jpa.show-sql=true 

@Configuration
public class DBConfig {

    
      
    @Primary
    @Bean(name = "integrationDataSource")
    @ConfigurationProperties(prefix = "integration.datasource")
    public DataSource integrationDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "mainDataSource")
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource mainDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Autowired
    @Bean(name = "integrationJdbcTemplate")
    public JdbcTemplate integrationJdbcTemplate(@Qualifier("integrationDataSource") DataSource integrationDataSource) {
        return new JdbcTemplate(integrationDataSource);
    }

    @Bean(name ="mainJdbcTemplate")
    @Autowired
    public JdbcTemplate mainJdbcTemplate(@Qualifier("mainDataSource") DataSource mainDataSource) {
        return new JdbcTemplate(mainDataSource);
    }
}

sampleClass.java

@Slf4j
@Component
public class SampleClass{

    @Autowired
    private  JdbcTemplate mainJdbcTemplate;
    
    @Autowired
    @Qualifier("integrationJdbcTemplate")
    private static JdbcTemplate integrationTemplate;
    
    public static final String SELECT_QUERY = "select * from tableA";

    public List<SampleDto> getDBData(SampleDto fileData) {
        List<SampleDto> data = null;
        try {
            data = integrationTemplate.query(
                    SampleClass.SELECT_QUERY, new Object[] { param1, param2 },
                    new SampleDataMapper());
        } catch (DataAccessException e) {
            log.error(e.getMessage(), e);
        }
        return data;
    }

}

在sampleClass.java am中，将integrationTemplate作为null。为什么会这样？mainJdbcTemplate正在工作。但是integrationTemplate变为null，无法导出查询。

Answer 1

问题是您有一个@autowired的静态字段

在@autowired中，字段是在bean构造之后，在调用任何配置方法之前注入的。阅读这里以获得更多关于Ioc和Bean注入的信息。

删除静态:

@Autowired
@Qualifier("integrationJdbcTemplate")
private JdbcTemplate integrationTemplate;

private static JdbcTemplate integrationTemplate;

@Autowired
public void setIntegrationJdbcTemplate(JdbcTemplate integrationTemplate){
    SampleClass.integrationTemplate = integrationTemplate;
}

@Autowired
private JdbcTemplate integrationJdbcTemplate;