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使用spring上下文对象+注解实现工厂模式取不同的bean!

程序员文章站 2022-05-23 10:19:28
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package com.coship.common.utils;

import com.coship.common.anno.MarkCode;
import org.apache.log4j.Logger;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import java.util.Map;

/**
 * @description Spring上下文工具类
 */
@Component
public class SpringContextUtil implements ApplicationContextAware {
    private static Logger logger = Logger.getLogger(SpringContextUtil.class);

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if (SpringContextUtil.applicationContext == null) {
            SpringContextUtil.applicationContext = applicationContext;
        }
        logger.info("初始化ApplicationContext:" + applicationContext);
    }

    /**
     * @return org.springframework.context.ApplicationContext
     * @description 获取applicationContext
     * @params []
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * @return java.lang.Object
     * @description 通过beanName获取Bean
     * @params [name]
     */
    public static Object getBean(String beanName) {
        return getApplicationContext().getBean(beanName);
    }

    /**
     * @return T
     * @description 通过class获取Bean
     * @params [clazz]
     */
    public static <T> T getBean(Class<T> clazz) {
        return getApplicationContext().getBean(clazz);
    }

    /**
     * @return T
     * @description 通过beanName和class返回指定的Bean
     * @params [name, clazz]
     */
    public static <T> T getBean(String name, Class<T> clazz) {
        return getApplicationContext().getBean(name, clazz);
    }

    /**
     * @return Map<String, T>
     * @description 获取指定类型的所有bean实例
     * @params [clazz]
     */
    public static <T> Map<String, T> getBeansByType(Class<T> clazz) {
        Map<String, T> instances = getApplicationContext().getBeansOfType(clazz);
        return instances;
    }

    /**
     * @return T
     * @description 根据类型和MarkCode注解值获取bean实例
     * @params [clazz, markCode]
     */
    public static <T> T getBeanByMarkCode(Class<T> clazz, String markCode) {
        Map<String, T> instances = getBeansByType(clazz);
        if (instances.isEmpty()) {
            logger.info("未获取到类型[" + clazz + "]Bean列表!");
            return null;
        }
        logger.info("获取类型[" + clazz + "]Bean列表:" + instances);
        for (String beanName : instances.keySet()) {
            T instance = instances.get(beanName);
            MarkCode code = instance.getClass().getAnnotation(MarkCode.class);
            if (null == code) {
                logger.info("BeanName[" + beanName + "]不包含MarkCode注解!");
                continue;
            }
            if (StringUtil.isNil(code.value())) {
                logger.info("BeanName[" + beanName + "]MarkCode注解值为空!");
                continue;
            }
            if (code.value().equals(markCode)) {
                return instance;
            }
        }

        return null;
    }

}
package com.coship.common.anno;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * @description 标记码注解(主要用来获取bean实例)
 */
@Documented
@Retention(RUNTIME)
@Target({ElementType.TYPE})
public @interface MarkCode {
    String value() default "";
}

调用示例:

 List<RuleSceneTriggerParam> triggerConditions = saveRuleSceneDetailDto.getTriggerConditions();
        if (!triggerConditions.isEmpty()) {
            RuleSceneDetailService ruleSceneTriggerService = SpringContextUtil.getBeanByMarkCode(RuleSceneDetailService.class, "trigger");
            ruleSceneTriggerService.saveDetailData(new SaveRuleSceneTriggerDataDto(triggerConditions, spCode, ruleId, ruleName, creUserId));
        }