1.目录

java_Scope_6">2.MyScope.java 自定义的Scope注解枚举

java">package com.sunxiansheng.sunspring.annotation.myenum;/*** Description: 自定义Scope注解，用于指定bean的作用域* @Author sun* @Create 2024/8/5 13:29* @Version 1.0*/
public enum MyScope {SINGLETON,PROTOTYPE;
}

java_Scope_26">3.Scope.java 自定义Scope注解

java">package com.sunxiansheng.sunspring.annotation;import com.sunxiansheng.sunspring.annotation.myenum.MyScope;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;/*** Description: 自定义Scope注解，用于指定bean的作用域* @Author sun* @Create 2024/8/5 13:28* @Version 1.0*/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Scope {MyScope value() default MyScope.SINGLETON;}

java_bean_54">4.MonsterService.java 指定bean的作用域

java">package com.sunxiansheng.sunspring.compent;import com.sunxiansheng.sunspring.annotation.Component;
import com.sunxiansheng.sunspring.annotation.Scope;
import com.sunxiansheng.sunspring.annotation.myenum.MyScope;/*** Description: 怪物服务* @Author sun* @Create 2024/8/4 16:31* @Version 1.0*/
// 自定义注解：将MonsterService类交给自定义Spring容器管理
// 如果指定value属性，则使用value属性值作为bean的id，否则使用类名首字母小写作为bean的id
@Component
@Scope(value = MyScope.PROTOTYPE) // 指定bean的作用域为多例
public class MonsterService {
}

java_bean_77">5.BeanDefintion.java bean的定义信息

java">package com.sunxiansheng.sunspring.ioc;import com.sunxiansheng.sunspring.annotation.myenum.MyScope;/*** Description: Bean定义类，记录bean的信息* @Author sun* @Create 2024/8/5 13:41* @Version 1.0*/
public class BeanDefintion {// bean的作用域private MyScope scope;// bean的类型private Class<?> clazz;public MyScope getScope() {return scope;}public void setScope(MyScope scope) {this.scope = scope;}public Class<?> getClazz() {return clazz;}public void setClazz(Class<?> clazz) {this.clazz = clazz;}@Overridepublic String toString() {return "BeanDefintion{" +"scope='" + scope + '\'' +", clazz=" + clazz +'}';}}

java_Spring_125">6.SunSpringApplicationContext.java Spring容器

java">package com.sunxiansheng.sunspring.ioc;import com.sunxiansheng.sunspring.annotation.Component;
import com.sunxiansheng.sunspring.annotation.ComponentScan;
import com.sunxiansheng.sunspring.annotation.Scope;
import com.sunxiansheng.sunspring.annotation.myenum.MyScope;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.io.File;
import java.net.URL;
import java.util.concurrent.ConcurrentHashMap;/*** Description: 自定义Spring容器* @Author sun* @Create 2024/8/4 16:35* @Version 1.0*/
public class SunSpringApplicationContext {private static final Logger log = LoggerFactory.getLogger(SunSpringApplicationContext.class);/*** bean定义的map*/private ConcurrentHashMap<String, BeanDefintion> beanDefintionMap = new ConcurrentHashMap<>();/*** 单例池*/private ConcurrentHashMap<String, Object> singletonObjects = new ConcurrentHashMap<>();// 构造器，接收配置类的class对象public SunSpringApplicationContext(Class<?> configClass) throws ClassNotFoundException, InstantiationException, IllegalAccessException {// 完成bean的扫描，将bean的信息记录到beanDefintionMap中beanDefinitionScan(configClass);}/*** 完成bean的扫描，将bean的信息记录到beanDefintionMap中* @param configClass* @throws ClassNotFoundException*/private void beanDefinitionScan(Class<?> configClass) throws ClassNotFoundException {// 传进来一个配置类的Class对象// 一、获取要扫描的包// 1.首先反射获取类的注解信息ComponentScan componentScan = configClass.getDeclaredAnnotation(ComponentScan.class);// 2.通过注解来获取要扫描的包的路径String path = componentScan.packagePath();log.info("要扫描的包路径为={}", path);// 二、得到要扫描包的.class文件对象，从而得到全路径进行反射// 1.获取App类加载器ClassLoader classLoader = SunSpringApplicationContext.class.getClassLoader();// 2.获取要扫描包的真实路径，默认刚开始在根目录下path = path.replace(".", "/");URL resource = classLoader.getResource(path);// 3.由该路径创建一个文件对象，可使用resource.getFile()将URL类型转化为String类型File file = new File(resource.getFile());// 4.遍历该文件夹下的所有.class文件对象if (file.isDirectory()) {File[] files = file.listFiles();for (File f : files) {// 反射注入容器// 1.获取所有文件的绝对路径String absolutePath = f.getAbsolutePath();// 只处理class文件if (absolutePath.endsWith(".class")) {// 2.分割出类名String className = extractClassName(absolutePath);// 3.得到全路径String fullPath = path.replace("/", ".") + "." + className;// 4.判断是否需要注入容器，查看有没有自定义的注解ComponentClass<?> aClass = classLoader.loadClass(fullPath);// 如果该类使用了注解Component则说明是一个spring beanif (aClass.isAnnotationPresent(Component.class)) {log.info("这是一个Spring bean={}", aClass);// 将bean的信息记录到beanDefintionMap中BeanDefintion beanDefintion = new BeanDefintion();// 1.获取Scope注解的value值if (aClass.isAnnotationPresent(Scope.class)) {Scope scope = aClass.getDeclaredAnnotation(Scope.class);MyScope value = scope.value();// 放到beanDefintion中beanDefintion.setScope(value);} else {// 如果没有指定作用域，则默认为单例beanDefintion.setScope(MyScope.SINGLETON);}beanDefintion.setClazz(aClass);// 2.获取Component注解的value值Component component = aClass.getDeclaredAnnotation(Component.class);String beanName = component.value();if ("".equals(beanName)) {// 如果没有指定value属性，则使用类名首字母小写作为bean的idbeanName = className.substring(0, 1).toLowerCase() + className.substring(1);}// 3.将bean的id和bean的信息放到beanDefintionMap中beanDefintionMap.put(beanName, beanDefintion);// 打印bean的信息log.info("beanName={}, beanDefintion={}", beanName, beanDefintion);} else {log.info("这不是一个Spring bean={}", aClass);}}}}}// 返回容器中的对象public Object getBean(String name) {return null;}/*** 分割出类名* 类似于 com/sunxiansheng/sunspring/compent/MonsterService.class 的类名* @param filePath* @return*/private String extractClassName(String filePath) {// 获取最后一个 '/' 的位置int lastSlashIndex = filePath.lastIndexOf('/');// 获取最后一个 '.' 的位置int lastDotIndex = filePath.lastIndexOf('.');// 提取两者之间的字符串作为类名return filePath.substring(lastSlashIndex + 1, lastDotIndex);}}

7.测试