所有的核心逻辑全部写在一个init()方法中。

public class V1DispatcherServlet extends HttpServlet {private Map<String,Object> mapping = new HashMap<String, Object>();@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doPost(req,resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {try {doDispatch(req,resp);} catch (Exception e) {resp.getWriter().write("500 Exception " + Arrays.toString(e.getStackTrace()));}}private void doDispatch(HttpServletRequest req, HttpServletResponse resp) throws Exception {String url = req.getRequestURI();String contextPath = req.getContextPath();url = url.replace(contextPath, "").replaceAll("/+", "/");if(!this.mapping.containsKey(url)){resp.getWriter().write("404 Not Found!!");return;}Method method = (Method) this.mapping.get(url);Map<String,String[]> params = req.getParameterMap();method.invoke(this.mapping.get(method.getDeclaringClass().getName()),new Object[]{req,resp,params.get("name")[0]});}//当我晕车的时候，我就不去看源码了//init方法肯定干得的初始化的工作//inti首先我得初始化所有的相关的类，IOC容器、servletBean@Overridepublic void init(ServletConfig config) throws ServletException {InputStream is = null;try{Properties configContext = new Properties();is = this.getClass().getClassLoader().getResourceAsStream(config.getInitParameter("contextConfigLocation"));configContext.load(is);String scanPackage = configContext.getProperty("scanPackage");doScanner(scanPackage);for (String className : mapping.keySet()) {if(!className.contains(".")){continue;}Class<?> clazz = Class.forName(className);if(clazz.isAnnotationPresent(V1Controller.class)){mapping.put(className,clazz.newInstance());String baseUrl = "";if (clazz.isAnnotationPresent(V1RequestMapping.class)) {V1RequestMapping requestMapping = clazz.getAnnotation(V1RequestMapping.class);baseUrl = requestMapping.value();}Method[] methods = clazz.getMethods();for (Method method : methods) {if (!method.isAnnotationPresent(V1RequestMapping.class)) {  continue; }V1RequestMapping requestMapping = method.getAnnotation(V1RequestMapping.class);String url = (baseUrl + "/" + requestMapping.value()).replaceAll("/+", "/");mapping.put(url, method);System.out.println("Mapped " + url + "," + method);}}else if(clazz.isAnnotationPresent(V1Service.class)){V1Service service = clazz.getAnnotation(V1Service.class);String beanName = service.value();if("".equals(beanName)){beanName = clazz.getName();}Object instance = clazz.newInstance();mapping.put(beanName,instance);for (Class<?> i : clazz.getInterfaces()) {mapping.put(i.getName(),instance);}}else {continue;}}for (Object object : mapping.values()) {if(object == null){continue;}Class clazz = object.getClass();if(clazz.isAnnotationPresent(V1Controller.class)){Field [] fields = clazz.getDeclaredFields();for (Field field : fields) {if(!field.isAnnotationPresent(V1Autowired.class)){continue; }V1Autowired autowired = field.getAnnotation(V1Autowired.class);String beanName = autowired.value();if("".equals(beanName)){beanName = field.getType().getName();}field.setAccessible(true);try {field.set(mapping.get(clazz.getName()),mapping.get(beanName));} catch (IllegalAccessException e) {e.printStackTrace();}}}}} catch (Exception e) {}finally {if(is != null){try {is.close();} catch (IOException e) {e.printStackTrace();}}}System.out.print("V1 MVC Framework is init");}private void doScanner(String scanPackage) {URL url = this.getClass().getClassLoader().getResource("/" + scanPackage.replaceAll("\\.","/"));File classDir = new File(url.getFile());for (File file : classDir.listFiles()) {if(file.isDirectory()){ doScanner(scanPackage + "." +  file.getName());}else {if(!file.getName().endsWith(".class")){continue;}String clazzName = (scanPackage + "." + file.getName().replace(".class",""));mapping.put(clazzName,null);}}}
}