1.demo
1-1.接口定义
包名：com.example.demo
接口：ITest
package com.example.demo;
public interface ITest {
void find();
}
1.2.接口使用
@Autowired
@Qualifier("myTest2") // ←自动注入不同的实现类
private ITest itest;
// 调用实现类的方法
itest.find();
1.3.同一jar中定义实现类
package com.example.demo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
@Component
public class MyTest2 implements ITest {
private static final Logger LOGGER = LoggerFactory.getLogger(MyTest2.class);
@Override
public void find() {
LOGGER.info("MyTest2#find");
}
}
2.demo01
在其他jar中定义实现类【**包名相同**】
package com.example.demo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
@Component
public class MyTest implements ITest {
private static final Logger LOGGER = LoggerFactory.getLogger(MyTest.class);
@Override
public void find() {
LOGGER.info("MyTest#find");
}
}
注）Springboot入口类：
@SpringBootApplication(scanBasePackages = { "com.example" })
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
然后修改上面【1.2.接口使用】中@Qualifier的实现类，运行后发现：
1.@Qualifier("myTest") -------> 运行失败，错误如下：
APPLICATION FAILED TO START
Description:
Field itest in com.example.demo.MyRunner required a bean of type 'com.example.demo.ITest' that could not be found.
Action:
Consider defining a bean of type 'com.example.demo.ITest' in your configuration.
2.@Qualifier("myTest2") -------> 运行成功
