Spring框架-two(重构javaEE三层结构)

曾经终败给现在 2022-03-11 08:42 198阅读 0赞

## 02-【熟悉】重构javaEE三层结构 ##

**1.传统方法**  
1.创建User  
![在这里插入图片描述][20190307170805708.png]  
2.创建UserDao  
![在这里插入图片描述][20190307170812871.png]  
3.创建UserDaoImpl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70]  
4.创建UserService  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 1]  
5.创建UserServiceImpl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 2]  
6.创建UserAction  
![在这里插入图片描述][20190307170842781.png]  
7.创建TestPro  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 3]  
8.存在问题  
如果现在 创建了新的ServiceImpl 或者DaoImpl的实现类，那么所有使用原来的Impl类的类里面的创建方式都要修改

**2.改良方法1 面向接口编程**  
1.创建UserFactory  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 4]  
2.修改UserAction  
![在这里插入图片描述][2019030717092647.png]  
3.修改OrderAction  
![在这里插入图片描述][2019030717093147.png]  
4.修改UserServiceImpl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 5]  
5.修改UserService2Impl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 6]  
6.存在问题  
如果类过多，那么要为每个类提供一个工厂 ，这个不现实

**3.改良方法2**  
1.创建BeanFactory  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 7]  
2.修改UserAction  
![在这里插入图片描述][20190307171000312.png]  
3.修改OrderAction  
![在这里插入图片描述][20190307171005300.png]  
4.修改UserServiceImpl  
![在这里插入图片描述][2019030717101148.png]  
5.修改UserService2Impl  
![在这里插入图片描述][20190307171018172.png]  
6.存在问题？  
完全限定名还要更改

**4.改良方法3**  
1.创建bean.properties

userDao=com.sxt.dao.impl.UserDaoImpl
    userService=com.sxt.serivce.impl.UserService2Impl

2.修改BeanFactory

/**
     * 创建对象
     * 
     * @author LJH
     * 
     */
    public class BeanFactory {
        
    	
    	/**
    	 * 	解析bean.properties
    	 */
    	private static Properties properties=new Properties();
    	
    	static{
        
    		InputStream 
    		 inStream=BeanFactory.class.getResourceAsStream("/bean.properties");
    		try {
        
    			properties.load(inStream);
    		} catch (IOException e) {
        
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 构造对象
    	 * 
    	 * @param name
    	 * @return
    	 */
    	@SuppressWarnings("unchecked")
    	public static <T> T getBean(String name) {
        
    		Class<?> forName;
    		Object obj = null;
    		try {
        
    			//根据name 去Properties里面找有没有对应的完全限定名
    			String realName=properties.getProperty(name);
    			if(null==realName){
        
    				throw new Exception("ioc容器里面没有配置关的key");
    			}
    			forName = Class.forName(realName);
    			obj = forName.newInstance();
    		} catch (Exception e) {
        
    			e.printStackTrace();
    		}
    		return (T) obj;
    	}
    	
    	
    	
    }

3.修改UserAction  
![在这里插入图片描述][20190307171125144.png]  
4.修改OrderAction  
![在这里插入图片描述][20190307171131394.png]  
5.修改UserServiceImpl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 8]

6.修改UserService2Impl  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 9]

[20190307170805708.png]: /images/20220311/4ef4c65bf72546a2b01c03de6a723a26.png
[20190307170812871.png]: /images/20220311/b7e326aa336845828757809fdfeb1b22.png
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[20190307170842781.png]: /images/20220311/4babdba501fd457b8a35841ab2cdd116.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 3]: /images/20220311/3aa3864c0ffa4129b7e5dba4603082d0.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0MDEzNzkw_size_16_color_FFFFFF_t_70 4]: /images/20220311/752c51d7c7c048b88b725c6c7dd3aa61.png
[2019030717092647.png]: /images/20220311/b096d1f577ab4ba3aacc8564634d3f84.png
[2019030717093147.png]: /images/20220311/9027dab0a8d640968c3e21a22f86f831.png
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[20190307171000312.png]: /images/20220311/b22208f2bec84681b0f39a57bfb761dc.png
[20190307171005300.png]: /images/20220311/07b7771a6bfd4d76ae5232c46b2a22be.png
[2019030717101148.png]: /images/20220311/d01f3b1f22a7470db6c8318d1dc49545.png
[20190307171018172.png]: /images/20220311/04d0e9d85a1040b195c2ee309fe2c02f.png
[20190307171125144.png]: /images/20220311/0d9d3bca964a40fa83f8accf6e0dc9d5.png
[20190307171131394.png]: /images/20220311/bcabab4a63104b23a4f8a7b196f10afa.png
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