解决:SSM框架中普通类调用Service的问题

最近在写一个项目，需要创建一个数据库初始化的工具类，用到了调用service的部分，不过可惜的是，Spring中的Service不是你想new就能new的，作为老菜鸟，研究了小半天终于搞定了，下面就来说说具体实现的方法。

1.创建一个SpringContextUtil实现ApplicationContextAware接口

import org.apache.log4j.Logger;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @作者：JackHisen(GWD)
 * @项目名：pet-commonTest
 * @时间：2017-6-19 下午6:03:01
 * @version 1.0
 */
@Component
public class SpringContextUtil implements ApplicationContextAware {
    private static Logger logger = Logger.getLogger(SpringContextUtil.class);
    private static ApplicationContext applicationContext = null;

    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
    {
        logger.info("------SpringContextUtil setApplicationContext-------");
        SpringContextUtil.applicationContext = applicationContext;
    }

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * 注意 bean name默认 = 类名(首字母小写)
     * 例如: A8sClusterDao = getBean("k8sClusterDao")
     * @param name
     * @return
     * @throws BeansException
     */
    public static Object getBean(String name) throws BeansException {
        return applicationContext.getBean(name);
    }

    /**
     * 根据类名获取到bean
     * @param <T>
     * @param clazz
     * @return
     * @throws BeansException
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBeanByName(Class<T> clazz) throws BeansException {
        try {
            char[] cs=clazz.getSimpleName().toCharArray();
            cs[0] += 32;//首字母大写到小写
            return (T) applicationContext.getBean(String.valueOf(cs));
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        } 
    }

    public static boolean containsBean(String name) {
        return applicationContext.containsBean(name);
    }

    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
        return applicationContext.isSingleton(name);
    }

}

2.在web项目中的web.xml中配置加载Spring容器的Listener

<listener>  
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  
    </listener>  

3.Service类的注解问题：

该方法实现了ParamInfoService接口，注意上面的注解以及注解内的名称（开头小写）

@Service("paramInfoService")
public class ParamInfoServiceImp implements ParamInfoService {
@Autowired
private ParamInfoMapper paramInfoMapper;

@Override
public List<ParamInfo> getAll() {
// TODO Auto-generated method stub
return paramInfoMapper.findAll();
}

}

4.普通类调用Service的方法

注意：这里面getBean内的名称需要和Service实现类中注解的名称一致

public static void loadAllParamInfo(){
ParamInfoService paramInfoService=(ParamInfoService)SpringContextUtil.getBean("paramInfoService");     
List<ParamInfo>datas=paramInfoService.getAll();
if(datas==null)return;
paramMap = new HashMap<String, ParamInfo>(datas.size());
for (ParamInfo bean : datas) {
paramMap.put(bean.getParamNameEn(), bean);
}
System.out.println("加载到参数共[" + paramMap.keySet().size() + "]个");
logger.debug("加载到参数共[" + paramMap.keySet().size() + "]个");
}