@qualifier不工作

Question

我有3个数据源，我设置如下：

@Configuration
@Component
public class DataSourceConfig {

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

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

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

}

我正在尝试将它们自动加入到我的消费者阶层中，如下所示：

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

@Component
public class MyClass {

    @Autowired
    public MyClass(
            @Autowired @Qualifier("foo") DataSource foo,
            @Autowired @Qualifier("bar") DataSource bar,
            @Autowired @Qualifier("baz") DataSource baz
            ) {
        ;
    }

}

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

Description:

Parameter 0 of constructor in com.example.mypackage.MyClass required a single bean, but 3 were found:
    - foo: defined by method 'foo' in class path resource [com/example/DataSourceConfig.class]
    - bar: defined by method 'bar' in class path resource [com/example/DataSourceConfig.class]
    - baz: defined by method 'baz' in class path resource [com/example/DataSourceConfig.class] 

Answer 1

通过添加@primary注释，使其中一个bean成为主bean。则应识别限定符。