<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><display-name>HandWriting Web Application</display-name><servlet><servlet-name>HandWriting MVC</servlet-name><servlet-class>com.wbg.framework.webmvc.servlet.HandWritingServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>application.properties</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>HandWriting MVC</servlet-name><url-pattern>/*</url-pattern></servlet-mapping>
</web-app>

package com.wbg.framework.webmvc.annotation;import java.lang.annotation.*;@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HandWritingAutowired {String value() default "";
}

package com.wbg.framework.webmvc.annotation;import java.lang.annotation.*;@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HandWritingController {String value() default "";
}

package com.wbg.framework.webmvc.annotation;import java.lang.annotation.*;@Target({ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HandWritingRequestMapping {String value() default "";
}

package com.wbg.framework.webmvc.annotation;import java.lang.annotation.*;@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HandWritingRequestParam {String value() default "";
}

package com.wbg.framework.webmvc.annotation;import java.lang.annotation.*;@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface HandWritingService {String value() default "";
}

package com.wbg.framework.webmvc.servlet;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class HandWritingServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {}@Overridepublic void init(ServletConfig config) throws ServletException {super.init(config);}
}

package com.wbg.framework.webmvc.servlet;import com.wbg.framework.webmvc.annotation.*;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.net.URL;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;public class HandWritingServlet extends HttpServlet {//配置文件private Properties contextConfig = new Properties();//存配置文件 scanPackage=com.wbg.demo 下所有的类名private List<String> classNames = new ArrayList<String>();//IOC容器private Map<String, Object> ioc = new HashMap<String, Object>();//保存所有的URL和方法的映射关系private List<Handler> handlerMapping = new ArrayList<Handler>();@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) {this.doPost(req, resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) {try {doDispatch(req, resp);} catch (Exception e) {try {resp.getWriter().write("500 =========" + e);} catch (IOException e1) {e1.printStackTrace();}}}/*** 初始化，加载配置* @param config 配置文件*/@Overridepublic void init(ServletConfig config) {System.out.println("======初始化配置文件======");//1、加载配置文件  获取web.xml文件的的param-namedoLoadConfig(config.getInitParameter("contextConfigLocation"));//2、扫描所有相关联的类 //配置文件的scanPackage = com...doScanner(contextConfig.getProperty("scanPackage"));//3、初始化所有相关的类，并且将其保存到IOC容器之中
        doInstance();//4、执行依赖注入（把加了@Autoidwired注解的字段赋值）
        doAutoWired();//-------------------------Spring的核心功能已经完成  IOC  DI注入//5、构造HandlerMapping,将URL和Method进行关联
        initHandlerMapping();System.out.println("=========启动完毕============");}/*** 构造HandlerMapping,将URL和Method进行关联*/private void initHandlerMapping() {if (ioc.isEmpty()) {return;}for (Map.Entry<String, Object> entry : ioc.entrySet()) {Class<?> clazz = entry.getValue().getClass();//如果该类上没有Controller  下一个if (!clazz.isAnnotationPresent(HandWritingController.class)) {continue;}String baseUrl = "";//如果该类上有RequestMapping注解if (clazz.isAnnotationPresent(HandWritingRequestMapping.class)) {HandWritingRequestMapping requestMapping = clazz.getAnnotation(HandWritingRequestMapping.class);//获取RequestMapping注解的值baseUrl = requestMapping.value();}//获取该类的所有方法Method[] methods = clazz.getMethods();for (Method method : methods) {//如果该方法上面没有RequestMapping 下一个if (!method.isAnnotationPresent(HandWritingRequestMapping.class)) {continue;}HandWritingRequestMapping requestMapping = method.getAnnotation(HandWritingRequestMapping.class);//获取RequestMapping注解的值String regex = requestMapping.value();//将 类上、方法上 的RequestMapping 注解相加  得到一个urlregex = (baseUrl + regex).replaceAll("/+", "/");Pattern pattern = Pattern.compile(regex);handlerMapping.add(new Handler(pattern, entry.getValue(), method));System.out.println("handlerMapping：" + regex);}}}/*** 执行依赖注入 将加了AutoWired注解的字段进行赋值* 注入的意思就是把所有IOC容器中加了@Autowired注解的字段全部赋值*/private void doAutoWired() {if (ioc.isEmpty()) {return;}for (Map.Entry<String, Object> entry : ioc.entrySet()) {//获取该类的声明字段 包过私有的字段Field[] fields = entry.getValue().getClass().getDeclaredFields();//循环加入IOC容器for (Field field : fields) {//如果字段不加Autowired注解  下一个if (!field.isAnnotationPresent(HandWritingAutowired.class)) {continue;}//获取这个字段上的Autowired注解HandWritingAutowired autowired = field.getAnnotation(HandWritingAutowired.class);//获取注解上的valueString beanName = autowired.value().trim();//如果为空if ("".equals(beanName)) {//获取这个字段的名字beanName = field.getType().getName();}//如果这个字段是私有的字段，强制访问field.setAccessible(true);try {//赋值
                    field.set(entry.getValue(), ioc.get(beanName));} catch (IllegalAccessException e) {e.printStackTrace();}}}}/*** 初始化所有相关的类* 加了注解的才初始化*/private void doInstance() {if (classNames.isEmpty()) {return;}for (String className : classNames) {try {Class<?> clazz = Class.forName(className);//只有加了注解的  才初始化if (clazz.isAnnotationPresent(HandWritingController.class)) {Object instance = clazz.newInstance();String beanName = lowerFirstClass(clazz.getSimpleName());ioc.put(beanName, instance);} else if (clazz.isAnnotationPresent(HandWritingService.class)) {HandWritingService service = clazz.getAnnotation(HandWritingService.class);//2、自定义命名，优先使用自定义命名String beanName = service.value();//1、默认类名首字母小写if ("".equals(beanName.trim())) {beanName = lowerFirstClass(clazz.getSimpleName());}Object instance = clazz.newInstance();ioc.put(beanName, instance);// 3、自动类型匹配（例如将实现类赋值给接口）Class<?>[] instances = clazz.getInterfaces();for (Class<?> i : instances) {ioc.put(i.getName(), instance);}} else {continue;}} catch (Exception e) {e.printStackTrace();}}}/*** 将字符串的首字母变成小写  利用ASCII转换* @param simpleName* @return*/private String lowerFirstClass(String simpleName) {char[] c = simpleName.toCharArray();c[0] += 32;return String.valueOf(c);}protected void doDispatch(HttpServletRequest req, HttpServletResponse resp) throws Exception {Handler handler = getHandler(req);//如果为空  没有这个请求路径if (handler == null) {resp.getWriter().write("=========handWritingSpring=============404==========");return;}try {//获取方法的参数列表Class<?>[] paramTypes = handler.method.getParameterTypes();//保存所有需要自动赋值的参数值Object[] paramValues = new Object[paramTypes.length];//获取方法上的参数Map<String, String[]> params = req.getParameterMap();for (Map.Entry<String, String[]> param : params.entrySet()) {//转换为String 去掉数组[]两边 去掉字符的空白String value = Arrays.toString(param.getValue()).replaceAll("\\[|\\]", "").replaceAll("\\s", "");//如果找到匹配的对象，则开始填充参数值if (!handler.paramIndexMapping.containsKey(param.getKey())) {continue;}int index = handler.paramIndexMapping.get(param.getKey());paramValues[index] = convert(paramTypes[index], value);}int reqIndex = handler.paramIndexMapping.get(HttpServletRequest.class.getName());paramValues[reqIndex] = req;int respIndex = handler.paramIndexMapping.get(HttpServletResponse.class.getName());paramValues[respIndex] = resp;handler.method.invoke(handler.controller, paramValues);} catch (Exception e) {throw e;}}private Handler getHandler(HttpServletRequest req) throws Exception {if (handlerMapping.isEmpty()) {return null;}String url = req.getRequestURI();String contextPath = req.getContextPath();url = url.replaceAll(contextPath, "").replaceAll("/+", "/");for (Handler handler : handlerMapping) {try {Matcher matcher = handler.pattern.matcher(url);//如果没有匹配上继续下一个匹配if (!matcher.matches()) {continue;}return handler;} catch (Exception e) {throw e;}}return null;}/*** 转换类型Integer* @param type* @param value* @return*/private Object convert(Class<?> type, String value) {if (Integer.class == type) {return Integer.valueOf(value);}return value;}/*** 扫描basePackage路径下所以的类* @param basePackage*/private void doScanner(String basePackage) {//获取路径URL url = this.getClass().getClassLoader().getResource("/" + basePackage.replaceAll("\\.", "/"));File dir = new File(url.getFile());for (File file : dir.listFiles()) {//如果是一个文件夹if (file.isDirectory()) {//递归doScanner(basePackage + "." + file.getName());} else {//获取类名String className = basePackage + "." + file.getName().replace(".class", "");//将所有项目所有类存起来
                classNames.add(className);}}}/*** 加载配置文件* @param contextConfigLocation*/private void doLoadConfig(String contextConfigLocation) {InputStream is = this.getClass().getClassLoader().getResourceAsStream(contextConfigLocation);try {contextConfig.load(is);} catch (IOException e) {e.printStackTrace();} finally {if (null != is) {try {is.close();} catch (IOException e) {e.printStackTrace();}}}}/*** Handler记录Controller中的RequestMapping和Method对应的关系*/private class Handler {protected Object controller; //保存方法对应的实例protected Method method; //保存映射的方法protected Pattern pattern;  //RequestMapping存的URLprotected Map<String, Integer> paramIndexMapping; //参数顺序/*** 基本参数* @param pattern* @param controller* @param method*/protected Handler(Pattern pattern, Object controller, Method method) {this.pattern = pattern;this.controller = controller;this.method = method;paramIndexMapping = new HashMap<String, Integer>();putParamIndexMapping(method);}/*** 保存RequestParam注解的参数值* @param method 类的方法*/private void putParamIndexMapping(Method method) {//获取方法中加了注解的参数Annotation[][] pa = method.getParameterAnnotations();for (int i = 0; i < pa.length; i++) {for (Annotation annotation : pa[i]) {//如果使用到了HandWritingRequestParam注解if (annotation instanceof HandWritingRequestParam) {//获取该注解的值String paramName = ((HandWritingRequestParam) annotation).value();//如果这个值不为空if (!"".equals(paramName.trim())) {//保存参数
                            paramIndexMapping.put(paramName, i);}}}}//提取方法中的request和response参数Class<?>[] paramsTypes = method.getParameterTypes();for (int i = 0; i < paramsTypes.length; i++) {Class<?> type = paramsTypes[i];if (type == HttpServletRequest.class || type == HttpServletResponse.class) {paramIndexMapping.put(type.getName(), i);}}}}
}

package com.wbg.demo.mvc.action;import com.wbg.demo.service.DemoService;
import com.wbg.framework.webmvc.annotation.HandWritingAutowired;
import com.wbg.framework.webmvc.annotation.HandWritingController;
import com.wbg.framework.webmvc.annotation.HandWritingRequestMapping;
import com.wbg.framework.webmvc.annotation.HandWritingRequestParam;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;@HandWritingController
@HandWritingRequestMapping("/demo")
public class DemoAction {@HandWritingAutowiredprivate DemoService demoService;@HandWritingRequestMapping("/query.json")public void query(HttpServletRequest req, HttpServletResponse resp, @HandWritingRequestParam("name")String name){String result =  demoService.get(name);try{resp.getWriter().write(result);}catch (IOException e){e.printStackTrace();}}@HandWritingRequestMapping("/sum.json")public void sum(HttpServletRequest req, HttpServletResponse resp, @HandWritingRequestParam("a") Integer a, @HandWritingRequestParam("b") Integer b){String result =  demoService.sum(a,b);try{resp.getWriter().write(result);}catch (IOException e){e.printStackTrace();}}@HandWritingRequestMapping("/remove.json")public void remove(HttpServletRequest req, HttpServletResponse resp, @HandWritingRequestParam("id") String id){String result =  demoService.remove(id);try{resp.getWriter().write(result);}catch (IOException e){e.printStackTrace();}}
}