Spring手写Spring框架的IOC给简单类型和非简单类型赋值-----Spring框架

野性酷女 2024-03-23 21:59 69阅读 0赞

>     package org.myspringframework.core;
>     
>     import java.io.InputStream;
>     import java.lang.reflect.Constructor;
>     import java.lang.reflect.Field;
>     import java.lang.reflect.Method;
>     import java.util.HashMap;
>     import java.util.List;
>     import java.util.Map;
>     
>     import org.dom4j.Document;
>     import org.dom4j.DocumentException;
>     import org.dom4j.Element;
>     import org.dom4j.Node;
>     import org.dom4j.io.SAXReader;
>     import org.slf4j.Logger;
>     import org.slf4j.LoggerFactory;
>     
>     public class ClassPathXmlApplicationContext implements ApplicationContext
>     {
>         private static final Logger logger = LoggerFactory.getLogger(ClassPathXmlApplicationContext.class);
>         private Map<String,Object> singletonObjects = new HashMap<>();
>         //解析mySpring配置文件,初始化所有的Bean,配置文件应当放在类路径下
>         public ClassPathXmlApplicationContext(String configLocation)
>         {
>             try
>             {
>                 //这是DOM4J解析XML的核心对象
>                 SAXReader saxReader = new SAXReader();
>                 //用类加载器获取系统类加载器,系统类加载器能获取类路径当中的资源,再以流的形式获取资源
>                 InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream(configLocation);
>                 Document document = saxReader.read(in);
>                 //当XML文件有很多同名标签,如果需要获取就用//后加名字即可
>                 List<Node> list = document.selectNodes("//bean");
>     //            遍历Bean标签
>                 list.forEach(node -> {
>                     try
>                     {
>                         //向下转型,方法更丰富
>                         Element beanEle = (Element) node;
>                         //获取ID
>                         String id = beanEle.attributeValue("id");
>                         //获取className
>                         String className = beanEle.attributeValue("class");
>                         logger.info(id + className);
>                         //通过反射机制创建对象,将其放到Map集合中曝光
>                         Class clazz = Class.forName(className);
>                         Constructor constructor = clazz.getDeclaredConstructor();
>                         //bean对象
>                         Object o = constructor.newInstance();
>                         singletonObjects.put(id,o);
>                         logger.info(singletonObjects.toString());
>                     }
>                     catch(Exception e)
>                     {
>                         e.printStackTrace();
>                     }
>                 });
>                 //再次遍历一遍,以便给属性赋值
>                 list.forEach(node -> {
>                     try
>                     {
>                         Element beanEle = (Element)node;
>                         //再次获取ID
>                         String id = beanEle.attributeValue("id");
>                         String className = beanEle.attributeValue("class");
>                         Class clazz = Class.forName(className);
>                         //获取该标签的所有property标签
>                         List<Element> properties = beanEle.elements("property");
>                         //遍历所有的property标签
>                         properties.forEach(property -> {
>                             try
>                             {
>                                 //获取属性名
>                                 String propName = property.attributeValue("name");
>                                 logger.info(propName);
>                                 //获取set方法名
>                                 String methodName = "set" + propName.toUpperCase().charAt(0) + propName.substring(1);
>                                 Field field = clazz.getDeclaredField(propName);
>                                 //参数类型
>                                 Method method = clazz.getDeclaredMethod(methodName,field.getType());
>                                 //获取值,如果没有该值,则取到的内容为空
>                                 String ref = property.attributeValue("ref");
>                                 String value = property.attributeValue("value");
>                                 //真正的值
>                                 Object actualValue = null;
>                                 if(value != null)
>                                 {
>                                     //说明该值是简单类型,byte short int long float double boolean char
>                                     //Byte Short Integer Long Float Double Boolean Character String
>                                     //获取属性类名,getSimpleName可以去掉包名
>                                     String fieldType = field.getType().getSimpleName();
>                                     switch(fieldType)
>                                     {
>                                         case "byte":
>                                         {
>                                             actualValue = Byte.parseByte(value);
>                                             break;
>                                         }
>                                         case "short":
>                                         {
>                                             actualValue = Short.parseShort(value);
>                                             break;
>                                         }
>                                         case "int":
>                                         {
>                                             actualValue = Integer.parseInt(value);
>                                             break;
>                                         }
>                                         case "long":
>                                         {
>                                             actualValue = Long.parseLong(value);
>                                             break;
>                                         }
>                                         case "float":
>                                         {
>                                             actualValue = Float.parseFloat(value);
>                                             break;
>                                         }
>                                         case "double":
>                                         {
>                                             actualValue = Double.parseDouble(value);
>                                             break;
>                                         }
>                                         case "boolean":
>                                         {
>                                             actualValue = Boolean.parseBoolean(value);
>                                             break;
>                                         }
>                                         case "char":
>                                         {
>                                             actualValue = value.charAt(0);
>                                             break;
>                                         }
>                                         case "Byte":
>                                         {
>                                             actualValue = Byte.valueOf(value);
>                                             break;
>                                         }
>                                         case "Short":
>                                         {
>                                             actualValue = Short.valueOf(value);
>                                             break;
>                                         }
>                                         case "Integer":
>                                         {
>                                             actualValue = Integer.valueOf(value);
>                                             break;
>                                         }
>                                         case "Long":
>                                         {
>                                             actualValue = Long.valueOf(value);
>                                             break;
>                                         }
>                                         case "Float":
>                                         {
>                                             actualValue = Float.valueOf(value);
>                                             break;
>                                         }
>                                         case "Double":
>                                         {
>                                             actualValue = Double.valueOf(value);
>                                             break;
>                                         }
>                                         case "Boolean":
>                                         {
>                                             actualValue = Boolean.valueOf(value);
>                                             break;
>                                         }
>                                         case "Character":
>                                         {
>                                             actualValue = Character.valueOf(value.charAt(0));
>                                             break;
>                                         }
>                                         case "String":
>                                         {
>                                             actualValue = value;
>                                             break;
>                                         }
>                                     }
>                                     method.invoke(singletonObjects.get(id),actualValue);
>                                 }
>                                 if(ref != null)
>                                 {
>                                     //说明该值不是简单类型
>                                     method.invoke(singletonObjects.get(id),singletonObjects.get(ref));
>                                 }
>                                 //SET方法没有返回值
>                             }
>                             catch (Exception e)
>                             {
>                                 e.printStackTrace();
>                             }
>                         });
>                     }
>                     catch(Exception e)
>                     {
>                         e.printStackTrace();
>                     }
>                 });
>                 //解析XML文件,实例化Bean,把Bean放到map容器中
>                 //getBean方法就变成了调用get()方法,并传入一个key即Bean的ID即可
>             }
>             catch (DocumentException e)
>             {
>                 e.printStackTrace();
>             }
>         }
>         @Override
>         public Object getBean(String name)
>         {
>             return singletonObjects.get(name);
>         }
>     }
> 
> package org.myspringframework.core;  
>   
> import java.io.InputStream;  
> import java.lang.reflect.Constructor;  
> import java.lang.reflect.Field;  
> import java.lang.reflect.Method;  
> import java.util.HashMap;  
> import java.util.List;  
> import java.util.Map;  
>   
> import org.dom4j.Document;  
> import org.dom4j.DocumentException;  
> import org.dom4j.Element;  
> import org.dom4j.Node;  
> import org.dom4j.io.SAXReader;  
> import org.slf4j.Logger;  
> import org.slf4j.LoggerFactory;  
>   
> public class ClassPathXmlApplicationContext implements ApplicationContext  
> \{  
> private static final Logger logger = LoggerFactory.getLogger(ClassPathXmlApplicationContext.class);  
> private Map<String,Object> singletonObjects = new HashMap<>();  
> //解析mySpring配置文件,初始化所有的Bean,配置文件应当放在类路径下  
> public ClassPathXmlApplicationContext(String configLocation)  
> \{  
> try  
> \{  
> //这是DOM4J解析XML的核心对象  
> SAXReader saxReader = new SAXReader();  
> //用类加载器获取系统类加载器,系统类加载器能获取类路径当中的资源,再以流的形式获取资源  
> InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream(configLocation);  
> Document document = saxReader.read(in);  
> //当XML文件有很多同名标签,如果需要获取就用//后加名字即可  
> List<Node> list = document.selectNodes("//bean");  
> // 遍历Bean标签  
> list.forEach(node -> \{  
> try  
> \{  
> //向下转型,方法更丰富  
> Element beanEle = (Element) node;  
> //获取ID  
> String id = beanEle.attributeValue("id");  
> //获取className  
> String className = beanEle.attributeValue("class");  
> logger.info(id + className);  
> //通过反射机制创建对象,将其放到Map集合中曝光  
> Class clazz = Class.forName(className);  
> Constructor constructor = clazz.getDeclaredConstructor();  
> //bean对象  
> Object o = constructor.newInstance();  
> singletonObjects.put(id,o);  
> logger.info(singletonObjects.toString());  
> \}  
> catch(Exception e)  
> \{  
> e.printStackTrace();  
> \}  
> \});  
> //再次遍历一遍,以便给属性赋值  
> list.forEach(node -> \{  
> try  
> \{  
> Element beanEle = (Element)node;  
> //再次获取ID  
> String id = beanEle.attributeValue("id");  
> String className = beanEle.attributeValue("class");  
> Class clazz = Class.forName(className);  
> //获取该标签的所有property标签  
> List<Element> properties = beanEle.elements("property");  
> //遍历所有的property标签  
> properties.forEach(property -> \{  
> try  
> \{  
> //获取属性名  
> String propName = property.attributeValue("name");  
> logger.info(propName);  
> //获取set方法名  
> String methodName = "set" + propName.toUpperCase().charAt(0) + propName.substring(1);  
> Field field = clazz.getDeclaredField(propName);  
> //参数类型  
> Method method = clazz.getDeclaredMethod(methodName,field.getType());  
> //获取值,如果没有该值,则取到的内容为空  
> String ref = property.attributeValue("ref");  
> String value = property.attributeValue("value");  
> //真正的值  
> Object actualValue = null;  
> if(value != null)  
> \{  
> //说明该值是简单类型,byte short int long float double boolean char  
> //Byte Short Integer Long Float Double Boolean Character String  
> //获取属性类名,getSimpleName可以去掉包名  
> String fieldType = field.getType().getSimpleName();  
> switch(fieldType)  
> \{  
> case "byte":  
> \{  
> actualValue = Byte.parseByte(value);  
> break;  
> \}  
> case "short":  
> \{  
> actualValue = Short.parseShort(value);  
> break;  
> \}  
> case "int":  
> \{  
> actualValue = Integer.parseInt(value);  
> break;  
> \}  
> case "long":  
> \{  
> actualValue = Long.parseLong(value);  
> break;  
> \}  
> case "float":  
> \{  
> actualValue = Float.parseFloat(value);  
> break;  
> \}  
> case "double":  
> \{  
> actualValue = Double.parseDouble(value);  
> break;  
> \}  
> case "boolean":  
> \{  
> actualValue = Boolean.parseBoolean(value);  
> break;  
> \}  
> case "char":  
> \{  
> actualValue = value.charAt(0);  
> break;  
> \}  
> case "Byte":  
> \{  
> actualValue = Byte.valueOf(value);  
> break;  
> \}  
> case "Short":  
> \{  
> actualValue = Short.valueOf(value);  
> break;  
> \}  
> case "Integer":  
> \{  
> actualValue = Integer.valueOf(value);  
> break;  
> \}  
> case "Long":  
> \{  
> actualValue = Long.valueOf(value);  
> break;  
> \}  
> case "Float":  
> \{  
> actualValue = Float.valueOf(value);  
> break;  
> \}  
> case "Double":  
> \{  
> actualValue = Double.valueOf(value);  
> break;  
> \}  
> case "Boolean":  
> \{  
> actualValue = Boolean.valueOf(value);  
> break;  
> \}  
> case "Character":  
> \{  
> actualValue = Character.valueOf(value.charAt(0));  
> break;  
> \}  
> case "String":  
> \{  
> actualValue = value;  
> break;  
> \}  
> \}  
> method.invoke(singletonObjects.get(id),actualValue);  
> \}  
> if(ref != null)  
> \{  
> //说明该值不是简单类型  
> method.invoke(singletonObjects.get(id),singletonObjects.get(ref));  
> \}  
> //SET方法没有返回值  
> \}  
> catch (Exception e)  
> \{  
> e.printStackTrace();  
> \}  
> \});  
> \}  
> catch(Exception e)  
> \{  
> e.printStackTrace();  
> \}  
> \});  
> //解析XML文件,实例化Bean,把Bean放到map容器中  
> //getBean方法就变成了调用get()方法,并传入一个key即Bean的ID即可  
> \}  
> catch (DocumentException e)  
> \{  
> e.printStackTrace();  
> \}  
> \}  
> @Override  
> public Object getBean(String name)  
> \{  
> return singletonObjects.get(name);  
> \}  
> \}

>     <?xml version="1.0" encoding="UTF-8"?>
>     
>     <beans>
>         <bean id="user" class="com.powernode.myspring.bean.User">
>             <property name="name" value="Jack"></property>
>             <property name="age" value="30"></property>
>         </bean>
>         <bean id="userDaoBean" class="com.powernode.myspring.bean.UserDao">
>         </bean>
>         <bean id="userService" class="com.powernode.myspring.bean.UserService">
>             <property name="userDao" ref="userDaoBean"></property>
>         </bean>
>     </beans>
> 
> <?xml version="1.0" encoding="UTF-8"?>  
>   
> <beans>  
> <bean id="user" class="com.powernode.myspring.bean.User">  
> <property name="name" value="Jack"></property>  
> <property name="age" value="30"></property>  
> </bean>  
> <bean id="userDaoBean" class="com.powernode.myspring.bean.UserDao">  
> </bean>  
> <bean id="userService" class="com.powernode.myspring.bean.UserService">  
> <property name="userDao" ref="userDaoBean"></property>  
> </bean>  
> </beans>

>     <?xml version="1.0" encoding="UTF-8"?>
>     <project xmlns="http://maven.apache.org/POM/4.0.0"
>              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>              xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
>         <modelVersion>4.0.0</modelVersion>
>     
>         <groupId>org.myspringframework</groupId>
>         <artifactId>myspring</artifactId>
>         <version>1.0.0</version>
>         <packaging>jar</packaging>
>         <dependencies>
>             <dependency>
>                 
>                 <groupId>org.dom4j</groupId>
>                 <artifactId>dom4j</artifactId>
>                 <version>2.1.3</version>
>             </dependency>
>             <dependency>
>                 <groupId>org.apache.logging.log4j</groupId>
>                 <artifactId>log4j-core</artifactId>
>                 <version>2.19.0</version>
>             </dependency>
>             <dependency>
>                 <groupId>org.apache.logging.log4j</groupId>
>                 <artifactId>log4j-slf4j2-impl</artifactId>
>                 <version>2.19.0</version>
>             </dependency>
>             
>             <dependency>
>                 <groupId>junit</groupId>
>                 <artifactId>junit</artifactId>
>                 <version>4.13.2</version>
>                 <scope>test</scope>
>             </dependency>
>             <dependency>
>                 <groupId>jaxen</groupId>
>                 <artifactId>jaxen</artifactId>
>                 <version>1.2.0</version>
>             </dependency>
>         </dependencies>
>         <properties>
>             <maven.compiler.source>17</maven.compiler.source>
>             <maven.compiler.target>17</maven.compiler.target>
>             <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
>         </properties>
>     
>     </project>
> 
> <?xml version="1.0" encoding="UTF-8"?>  
> <project xmlns="http://maven.apache.org/POM/4.0.0"  
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
> xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  
> <modelVersion>4.0.0</modelVersion>  
>   
> <groupId>org.myspringframework</groupId>  
> <artifactId>myspring</artifactId>  
> <version>1.0.0</version>  
> <packaging>jar</packaging>  
> <dependencies>  
> <dependency>  
>   
> <groupId>org.dom4j</groupId>  
> <artifactId>dom4j</artifactId>  
> <version>2.1.3</version>  
> </dependency>  
> <dependency>  
> <groupId>org.apache.logging.log4j</groupId>  
> <artifactId>log4j-core</artifactId>  
> <version>2.19.0</version>  
> </dependency>  
> <dependency>  
> <groupId>org.apache.logging.log4j</groupId>  
> <artifactId>log4j-slf4j2-impl</artifactId>  
> <version>2.19.0</version>  
> </dependency>  
>   
> <dependency>  
> <groupId>junit</groupId>  
> <artifactId>junit</artifactId>  
> <version>4.13.2</version>  
> <scope>test</scope>  
> </dependency>  
> <dependency>  
> <groupId>jaxen</groupId>  
> <artifactId>jaxen</artifactId>  
> <version>1.2.0</version>  
> </dependency>  
> </dependencies>  
> <properties>  
> <maven.compiler.source>17</maven.compiler.source>  
> <maven.compiler.target>17</maven.compiler.target>  
> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
> </properties>  
>   
> </project>

>     package com.powernode.myspring.test;
>     
>     import com.powernode.myspring.bean.User;
>     import com.powernode.myspring.bean.UserService;
>     import org.junit.Test;
>     import org.myspringframework.core.ApplicationContext;
>     import org.myspringframework.core.ClassPathXmlApplicationContext;
>     
>     public class MySpringTest
>     {
>         @Test
>         public void Test()
>         {
>             ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");
>             User user = (User)applicationContext.getBean("user");
>             System.out.println(user);
>             UserService service = (UserService) applicationContext.getBean("userService");
>             service.save();
>         }
>     }
> 
> package com.powernode.myspring.test;  
>   
> import com.powernode.myspring.bean.User;  
> import com.powernode.myspring.bean.UserService;  
> import org.junit.Test;  
> import org.myspringframework.core.ApplicationContext;  
> import org.myspringframework.core.ClassPathXmlApplicationContext;  
>   
> public class MySpringTest  
> \{  
> @Test  
> public void Test()  
> \{  
> ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");  
> User user = (User)applicationContext.getBean("user");  
> System.out.println(user);  
> UserService service = (UserService) applicationContext.getBean("userService");  
> service.save();  
> \}  
> \}

>     package com.powernode.myspring.bean;
>     
>     public class User
>     {
>         private String name;
>         private int age;
>     
>         public void setName(String name) {
>             this.name = name;
>         }
>     
>         @Override
>         public String toString() {
>             return "User{" +
>                     "name='" + name + '\'' +
>                     ", age=" + age +
>                     '}';
>         }
>     
>         public void setAge(int age) {
>             this.age = age;
>         }
>     }
> 
> package com.powernode.myspring.bean;  
>   
> public class User  
> \{  
> private String name;  
> private int age;  
>   
> public void setName(String name) \{  
> this.name = name;  
> \}  
>   
> @Override  
> public String toString() \{  
> return "User\{" +  
> "name='" + name + '\\'' +  
> ", age=" + age +  
> '\}';  
> \}  
>   
> public void setAge(int age) \{  
> this.age = age;  
> \}  
> \}

>     package com.powernode.myspring.bean;
>     
>     public class UserService
>     {
>         private UserDao userDao;
>     
>         public void setUserDao(UserDao userDao) {
>             this.userDao = userDao;
>         }
>     
>         public void save()
>         {
>             userDao.insert();
>         }
>     }
> 
> package com.powernode.myspring.bean;  
>   
> public class UserService  
> \{  
> private UserDao userDao;  
>   
> public void setUserDao(UserDao userDao) \{  
> this.userDao = userDao;  
> \}  
>   
> public void save()  
> \{  
> userDao.insert();  
> \}  
> \}

>     package org.myspringframework.core;
>     
>     public interface ApplicationContext
>     {
>         Object getBean(String name);
>     }
> 
> package org.myspringframework.core;  
>   
> public interface ApplicationContext  
> \{  
> Object getBean(String name);  
> \}