Java 选择在运行时注入哪个实现 spring
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/19231875/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Choose which implementation to inject at runtime spring
提问by kwh
I have the following classes:
我有以下课程：
public interface MyInterface{}
public class MyImpl1 implements MyInterface{}
public class MyImpl2 implements MyInterface{}
public class Runner {
@Autowired private MyInterface myInterface;
}
What I want to do is decide, whilst the app is already running (i.e. notat startup) which Implementation should be injected into Runner.
我想要做的是决定，当应用程序已经在运行（即不在启动时）时，应该将哪个实现注入到Runner.
So ideally something like this:
所以理想情况下是这样的：
ApplicationContext appContext = ...
Integer request = ...
Runner runner = null;
if (request == 1) {
//here the property 'myInterface' of 'Runner' would be injected with MyImpl1
runner = appContext.getBean(Runner.class)
}
else if (request == 2) {
//here the property 'myInterface' of 'Runner' would be injected with MyImpl2
runner = appContext.getBean(Runner.class)
}
runner.start();
What is the best way to accomplish this?
实现这一目标的最佳方法是什么？
采纳答案by acc15
Declare implementations with @Component("implForRq1")and @Component("implForRq2")
使用@Component("implForRq1")和声明实现@Component("implForRq2")
Then inject them both and use:
然后注入它们并使用：
class Runner {
@Autowired @Qualifier("implForRq1")
private MyInterface runnerOfRq1;
@Autowired @Qualifier("implForRq2")
private MyInterface runnerOfRq2;
void run(int rq) {
switch (rq) {
case 1: runnerOfRq1.run();
case 2: runnerOfRq2.run();
...
}
}
}
...
@Autowired
Runner runner;
void run(int rq) {
runner.run(rq);
}
