一、以靜態變量保存Spring ApplicationContext, 可在任何代碼任何地方任何時候取出ApplicaitonContext。適用於根據數據庫的配置取出對應定時任務的實現類

package com.wy.SpringBean;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
 
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;

/**
 * @description:以靜態變量保存Spring ApplicationContext, 可在任何代碼任何地方任何時候取出ApplicaitonContext，
 * 適用於根據數據庫的配置取出對應定時任務的實現類
 **/

@Component
public class
 
 SpringContextHolder implements ApplicationContextAware, DisposableBean {

    private static ApplicationContext applicationContext = null;

    private static Logger logger = LoggerFactory.getLogger(SpringContextHolder.class);

    /**
     * 取得存儲在靜態變量中的ApplicationContext.
     */
    public
 
 static ApplicationContext getApplicationContext() {
        assertContextInjected();
        return applicationContext;
    }

    /**
     * 從靜態變量applicationContext中取得Bean, 自動轉型為所賦值對象的類型.
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) {
        assertContextInjected();
        return (T) applicationContext.getBean(name);
    }

    /**
     * 從靜態變量applicationContext中取得Bean, 自動轉型為所賦值對象的類型.
     */
    public static <T> T getBean(Class<T> requiredType) {
        assertContextInjected();
        return applicationContext.getBean(requiredType);
    }

    /**
     * 清除SpringContextHolder中的ApplicationContext為Null.
     */
    public static void clearHolder() {
        logger.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
        applicationContext = null;
    }

    /**
     * 實現ApplicationContextAware接口, 註入Context到靜態變量中.
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        logger.debug("註入ApplicationContext到SpringContextHolder:" + applicationContext);

        if (SpringContextHolder.applicationContext != null) {
            logger.warn("SpringContextHolder中的ApplicationContext被覆蓋, 原有ApplicationContext為:"
                    + SpringContextHolder.applicationContext);
        }

        SpringContextHolder.applicationContext = applicationContext;
    }

    /**
     * 實現DisposableBean接口, 在Context關閉時清理靜態變量.
     */
    @Override
    public void destroy() throws Exception {
        SpringContextHolder.clearHolder();
    }

    /**
     * 檢查ApplicationContext不為空.
     */
    private static void assertContextInjected() {
        Assert.state(applicationContext != null,
                "applicaitonContext屬性未註入, 請在applicationContext.xml中定義SpringContextHolder.");
    }


}

二、定義接口

public interface TestInterface {

    void testInter(String str);
}

三、定義兩個個實現類

@Service("testImp01")
public class testImp01 implements TestInterface{
    @Override
    public void testInter(String str) {
        System.out.println("testImp01:"+str);
    }
}

@Service("testImp02")
public class testImp02 implements TestInterface{
    @Override
    public void testInter(String str) {
        System.out.println("testImp02:"+str);
    }
}

四、定義controller

@RestController
public class TestController {



    @RequestMapping("test01")
    public void test01() {
        TestInterface testInterface = SpringContextHolder.getBean("testImp01");
        testInterface.testInter("01");
    }
    @RequestMapping("test02")
    public void test02() {
        TestInterface testInterface = SpringContextHolder.getBean("testImp02");
        testInterface.testInter("02");
    }

}

啟動項目測試

一個接口多個實現類