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兰州城关区建设局网站,电子商务网站建设 课后答案,深圳网络营销推广,用宝塔做网站手写Spring框架 各位道友#xff0c;我发现现在贼卷底层代码#xff0c;看完源码发下几天后#xff0c;额#xff01;#xff01;#xff01;我当时看了啥#xff01; 还是自己写个迷你的spring框架#xff0c;这样印象更加深刻#xff0c;上干货#xff0c;代码仓…手写Spring框架 各位道友我发现现在贼卷底层代码看完源码发下几天后额我当时看了啥 还是自己写个迷你的spring框架这样印象更加深刻上干货代码仓库https://gitee.com/smd_somin/SmdSpring.git 上面是我写的迷你版的spring框架麻雀虽小五脏俱全主要包括下边的内容 容器启动BeanDefinition扫描Bean声明周期单例与多例依赖注入AOPaware回调初始化BeanPostProcessor增强器 下面是手写框架的过程和思路仅供大家参考!!! 相信大家总会遇到这样问题聊聊你理解的spring 这个基本是100个技术99个会遇到这个问题我谈一下我得理解仅供参考我认为spring可以用两行表示 //创建容器SmdApplicationContext context new SmdApplicationContext(AppConfig.class);//获取对象UserInterface userService (UserInterface) context.getBean(userService);在这两行代码所牵连的内容其实就是spring的本质对与bean的管理。 如果需要容器那么我们需要有一个容器类,下面是手写spring容器的全部代码这个也是逻辑的核心内容下面会分享一下思路建议对着源码看下 上面的代码可以整体分为两个步骤一个创建容器另一个是从容器中获取bean。 首先说说创建容器的过程 创建容器 - 扫描.class文件 - 适配文件路径 - 判断Component注解 - 符合注解进行反射获取对象 - 记录bean的信息类型单例- 创建对象 - 实例化对象 - 依赖注入 - aware增强类处理 - 处理BeanPostProcessor的 postProcessorBeforeInitialazition方法 - 初始化 - BeanProcessor的beanPostProcessorAfterInitailzaiton方法 -处理切面逻辑-bean创建成功 获取bean过程 主要区分单例还是多例单例从单例池中取多例新创建一个bean SmdApplicationContext package org.smd.spring;import java.beans.Introspector; import java.io.File; import java.lang.reflect.Field; import java.net.URL; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.smd.spring.annotation.Autowrite; import org.smd.spring.annotation.Component; import org.smd.spring.annotation.ScanComponent; import org.smd.spring.annotation.Scope; import org.smd.spring.aware.BeanNameAware; import org.smd.spring.init.InitializingBean;/*** author smd* zhName 容器* description: 容器*/ public class SmdApplicationContext {public MapString, BeanDefinition definitionMap new HashMap();public MapString, Object singletonBeanMap new HashMap();public ListBeanPostProcessor beanPostProcessorsnew ArrayListBeanPostProcessor();private Class configClass;public SmdApplicationContext(Class configClass) {this.configClass configClass;//扫描文件夹下数据if (configClass.isAnnotationPresent(ScanComponent.class)) {ScanComponent scanComponent (ScanComponent) configClass.getAnnotation(ScanComponent.class);//进行文件路径转化String path scanComponent.vaule();System.out.println(–scanComponent: path);path path.replace(., /);System.out.println(–scanComponent: path);//加载jar下.class文件ClassLoader classLoader SmdApplicationContext.class.getClassLoader();URL resource classLoader.getResource(path);File file new File(resource.getFile());if (file.isDirectory()) {for (File f : file.listFiles()) {String filePath f.getAbsolutePath();System.out.println(– file path: filePath);if (filePath.endsWith(.class)) {String filesName filePath.substring(filePath.indexOf(org), filePath.indexOf(.class));filesName filesName.replace(\, .);System.out.println(–file name filesName);try {Class? clazz classLoader.loadClass(filesName);if (clazz.isAnnotationPresent(Component.class)) {if(BeanPostProcessor.class.isAssignableFrom(clazz)){BeanPostProcessor beanPostProcessor(BeanPostProcessor) clazz.newInstance();beanPostProcessors.add(beanPostProcessor);}Component component clazz.getAnnotation(Component.class);//获取bean nameString name component.vaule();if (name.equals()) {name Introspector.decapitalize(clazz.getSimpleName());}//记录bean definitionBeanDefinition definition new BeanDefinition();definition.setType(clazz);if (clazz.isAnnotationPresent(Scope.class)) {Scope scope (Scope) clazz.getAnnotation(Scope.class);definition.setScope(scope.value());} else {definition.setScope(singleton);}//放入bean definition map中definitionMap.put(name, definition);}} catch (ClassNotFoundException e) {e.printStackTrace();} catch (IllegalAccessException e) {e.printStackTrace();} catch (InstantiationException e) {e.printStackTrace();}}}}}//初始化beanfor (String name : definitionMap.keySet()) {BeanDefinition definition definitionMap.get(name);Object bean this.createBean(name, definition);singletonBeanMap.put(name, bean);}}private Object createBean(String name, BeanDefinition definition) {Class clazz definition.getType();try {//实例化Object bean clazz.getConstructor().newInstance();//依赖注入for (Field field : clazz.getDeclaredFields()) {if (field.isAnnotationPresent(Autowrite.class)) {field.setAccessible(true);field.set(bean, getBean(field.getName()));}}// aware加强类回调if(bean instanceof BeanNameAware){((BeanNameAware)bean).setBeanName(name);}// 初始化前调用bean post processorfor (BeanPostProcessor beanPostProcessor : beanPostProcessors) {bean beanPostProcessor.postProcessorBeforeInitialization(name,bean);}// 初始化if(bean instanceof InitializingBean){((InitializingBean)bean).afterPropertiesSet();}// 初始化后调用bean post processorfor (BeanPostProcessor beanPostProcessor : beanPostProcessors) {bean beanPostProcessor.postProcessorAftertInitialization(name,bean);}return bean;} catch (Exception e) {e.printStackTrace();}return null;}public Object getBean(String name) {//获取definition信息BeanDefinition definition definitionMap.get(name);if (definition null) {System.out.println(–error: name);throw new NullPointerException();} else {//进行单例和多例区分if (definition.getScope().equals(singleton)) {Object bean singletonBeanMap.get(name);if (bean null) {return this.createBean(name, definition);} else {return bean;}} else {return this.createBean(name, definition);}}} } 各位道友前路漫漫~ 努力向远方前进吧 《真常之道悟者自得得悟道者常清静矣。》