自定义的依赖注入[Action层/Service层/DAO层分离 , 解耦]

工具类:

1. ServiceProvinderCore.java

package cn.itcast.crm.container;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
 * 提供service的容器, 这里自定义一个容器, 和action分离, 达到解耦的目的
 */
public class ServiceProvinderCore {
	protected ApplicationContext ctx;
	/**
	 * @param filename beans.xml
	 */
	public void load(String filename) {
		ctx = new ClassPathXmlApplicationContext(filename);
	}
}

2. ServiceProvinder.java

package cn.itcast.crm.container;
import org.apache.commons.lang.StringUtils;
/**
 * 该类的主要作用的是加载beans.xml文件
 */
public class ServiceProvinder {
	private static ServiceProvinderCore sc;
	static {
		sc = new ServiceProvinderCore();
		sc.load("beans.xml");
	}
	public static Object getService(String beanName) {
		if (StringUtils.isBlank(beanName)) {
			throw new RuntimeException("您要访问的服务名称不能为空");
		}
		Object bean = null;
		// 如果spring容器中包含beanName
		if (sc.ctx.containsBean(beanName)) {
			bean = sc.ctx.getBean(beanName);
		}
		// 如果spring容器不包含beanName
		if (bean == null) {
			throw new RuntimeException("您要访问的服务名称[ " + beanName + " ]不存在");
		}
		return bean;
	}
}

3. 使用:

(1) 在接口中声明全局常量, 包.类的形式

ISysUserService.java

public interface ISysUserService {
	public static final String SERVER_NAME = "cn.itcast.crm.service.impl.SysUserServiceImpl";
}

(2) 在接口实现类中加上注解@XXXX

SysUserServiceImpl.java

@Service(ISysUserService.SERVER_NAME)
public class SysUserServiceImpl implements ISysUserService {
    // 这里按照service的注入方法注入dao(dao接口和实现类写法和service一样)
}

(3) 在action中按下形式注入service

SysUserAction.java

public class SysUserAction extends BaseAction {
        // 注入service
	private ISysUserService sysUserService = (ISysUserService) ServiceProvinder.getService(ISysUserService.SERVER_NAME);
}