1. 本章须要实现的内容：
- 实现ControllerRequestProcessor类的编写： Controller申请处理器
- 实现JspRequestProcessor类的编写：jsp资源申请解决
- 实现PreRequestProcessor类的编写： 申请预处理,包含编码以及门路解决
- 实现StaticResourceRequestProcessor类的编写： 动态资源申请解决，包含但不限于图片，css，以及js文件等, 转发到DefaultServlet
2. PreRequestProcessor类的编写
2.1 PreRequestProcessor类须要实现的代码
package org.myframework.mvc.processor.impl;/** * @author wuyiccc * @date 2020/6/16 18:54 * 岂曰无衣，与子同袍~ */import lombok.extern.slf4j.Slf4j;import org.myframework.mvc.RequestProcessorChain;import org.myframework.mvc.processor.RequestProcessor;/** * 申请预处理,包含编码以及门路解决 */@Slf4jpublic class PreRequestProcessor implements RequestProcessor { @Override public boolean process(RequestProcessorChain requestProcessorChain) throws Exception { // 1.设置申请编码，将其对立设置成UTF-8 requestProcessorChain.getRequest().setCharacterEncoding("UTF-8"); // 2.将申请门路开端的/剔除，为后续匹配Controller申请门路做筹备 // （个别Controller的解决门路是/aaa/bbb，所以如果传入的门路结尾是/aaa/bbb/， // 就须要解决成/aaa/bbb） String requestPath = requestProcessorChain.getRequestPath(); //http://localhost:8080/myframework requestPath="/" if (requestPath.length() > 1 && requestPath.endsWith("/")) { requestProcessorChain.setRequestPath(requestPath.substring(0, requestPath.length() - 1)); } log.info("preprocess request {} {}", requestProcessorChain.getRequestMethod(), requestProcessorChain.getRequestPath()); return true; }}2.2 PreRequestProcessor类相干代码解说：
3. StaticResourceRequestProcessor类的编写
3.1 StaticResourceRequestProcessor类须要实现的代码:
package com.wuyiccc.helloframework.mvc.processor.impl;import com.wuyiccc.helloframework.mvc.RequestProcessorChain;import com.wuyiccc.helloframework.mvc.processor.RequestProcessor;import lombok.extern.slf4j.Slf4j;import javax.servlet.RequestDispatcher;import javax.servlet.ServletContext;/** * @author wuyiccc * @date 2020/7/14 22:40 * 岂曰无衣，与子同袍~ */@Slf4jpublic class StaticResourceRequestProcessor implements RequestProcessor { public static final String DEFAULT_TOMCAT_SERVLET = "default"; public static final String STATIC_RESOURCE_PREFIX = "/static/"; //tomcat默认申请派发器RequestDispatcher的名称 RequestDispatcher defaultDispatcher; public StaticResourceRequestProcessor(ServletContext servletContext) { this.defaultDispatcher = servletContext.getNamedDispatcher(DEFAULT_TOMCAT_SERVLET); if (this.defaultDispatcher == null) { throw new RuntimeException("There is no default tomcat servlet"); } log.info("The default servlet for static resource is {}", DEFAULT_TOMCAT_SERVLET); } @Override public boolean process(RequestProcessorChain requestProcessorChain) throws Exception { //1.通过申请门路判断是否是申请的动态资源 webapp/static if (isStaticResource(requestProcessorChain.getRequestPath())) { //2.如果是动态资源，则将申请转发给default servlet解决 defaultDispatcher.forward(requestProcessorChain.getRequest(), requestProcessorChain.getResponse()); return false; } return true; } //通过申请门路前缀（目录）是否为动态资源 /static/ private boolean isStaticResource(String path) { return path.startsWith(STATIC_RESOURCE_PREFIX); }}3.2 StaticResourceRequestProcessor类相干代码解说：
4. JspRequestProcessor
4.1 JspRequestProcessor须要实现的代码：
package org.myframework.mvc.processor.impl;import org.myframework.mvc.RequestProcessorChain;import org.myframework.mvc.processor.RequestProcessor;import javax.servlet.RequestDispatcher;import javax.servlet.ServletContext;/** * @author wuyiccc * @date 2020/6/16 18:59 * 岂曰无衣，与子同袍~ *//** * jsp资源申请解决 */public class JspRequestProcessor implements RequestProcessor { //jsp申请的RequestDispatcher的名称 private static final String JSP_SERVLET = "jsp"; //Jsp申请资源门路前缀 private static final String JSP_RESOURCE_PREFIX = "/templates/"; /** * jsp的RequestDispatcher,解决jsp资源 */ private RequestDispatcher jspServlet; public JspRequestProcessor(ServletContext servletContext) { jspServlet = servletContext.getNamedDispatcher(JSP_SERVLET); if (null == jspServlet) { throw new RuntimeException("there is no jsp servlet"); } } @Override public boolean process(RequestProcessorChain requestProcessorChain) throws Exception { if (isJspResource(requestProcessorChain.getRequestPath())) { jspServlet.forward(requestProcessorChain.getRequest(), requestProcessorChain.getResponse()); return false; } return true; } /** * 是否申请的是jsp资源 */ private boolean isJspResource(String url) { return url.startsWith(JSP_RESOURCE_PREFIX); }}4.2 JspRequestProcessor相干代码解说：
5. ControllerRequestProcessor类的编写
5.1 ControllerRequestProcessor须要实现的代码:
package org.myframework.mvc.processor.impl;import lombok.extern.slf4j.Slf4j;import org.myframework.core.BeanContainer;import org.myframework.mvc.RequestProcessorChain;import org.myframework.mvc.annotation.RequestMapping;import org.myframework.mvc.annotation.RequestParam;import org.myframework.mvc.annotation.ResponseBody;import org.myframework.mvc.processor.RequestProcessor;import org.myframework.mvc.render.JsonResultRender;import org.myframework.mvc.render.ResourceNotFoundResultRender;import org.myframework.mvc.render.ResultRender;import org.myframework.mvc.render.ViewResultRender;import org.myframework.mvc.type.ControllerMethod;import org.myframework.mvc.type.RequestPathInfo;import org.myframework.util.ConverterUtil;import org.myframework.util.ValidationUtil;import javax.servlet.http.HttpServletRequest;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.lang.reflect.Parameter;import java.util.*;import java.util.concurrent.ConcurrentHashMap;/** * @author wuyiccc * @date 2020/6/16 19:14 * 岂曰无衣，与子同袍~ *//** * Controller申请处理器 */@Slf4jpublic class ControllerRequestProcessor implements RequestProcessor { //IOC容器 private BeanContainer beanContainer; //申请和controller办法的映射汇合 private Map<RequestPathInfo, ControllerMethod> pathControllerMethodMap = new ConcurrentHashMap<>(); /** * 依附容器的能力，建设起申请门路、申请办法与Controller办法实例的映射 */ public ControllerRequestProcessor() { this.beanContainer = BeanContainer.getInstance(); Set<Class<?>> requestMappingSet = beanContainer.getClassesByAnnotation(RequestMapping.class); initPathControllerMethodMap(requestMappingSet); } private void initPathControllerMethodMap(Set<Class<?>> requestMappingSet) { if (ValidationUtil.isEmpty(requestMappingSet)) { return; } //1.遍历所有被@RequestMapping标记的类，获取类下面该注解的属性值作为一级门路 for (Class<?> requestMappingClass : requestMappingSet) { RequestMapping requestMapping = requestMappingClass.getAnnotation(RequestMapping.class); String basePath = requestMapping.value(); if (!basePath.startsWith("/")) { basePath = "/" + basePath; } //2.遍历类里所有被@RequestMapping标记的办法，获取办法下面该注解的属性值，作为二级门路 Method[] methods = requestMappingClass.getDeclaredMethods(); if (ValidationUtil.isEmpty(methods)) { continue; } for (Method method : methods) { if (method.isAnnotationPresent(RequestMapping.class)) { RequestMapping methodRequest = method.getAnnotation(RequestMapping.class); String methodPath = methodRequest.value(); if (!methodPath.startsWith("/")) { methodPath = "/" + basePath; } String url = basePath + methodPath; //3.解析办法里被@RequestParam标记的参数， // 获取该注解的属性值，作为参数名， // 获取被标记的参数的数据类型，建设参数名和参数类型的映射 Map<String, Class<?>> methodParams = new HashMap<>(); Parameter[] parameters = method.getParameters(); if (!ValidationUtil.isEmpty(parameters)) { for (Parameter parameter : parameters) { RequestParam param = parameter.getAnnotation(RequestParam.class); //目前暂定为Controller办法外面所有的参数都须要@RequestParam注解 if (param == null) { throw new RuntimeException("The parameter must have @RequestParam"); } methodParams.put(param.value(), parameter.getType()); } } //4.将获取到的信息封装成RequestPathInfo实例和ControllerMethod实例，搁置到映射表里 String httpMethod = String.valueOf(methodRequest.method()); RequestPathInfo requestPathInfo = new RequestPathInfo(httpMethod, url); if (this.pathControllerMethodMap.containsKey(requestPathInfo)) { log.warn("duplicate url:{} registration，current class {} method{} will override the former one", requestPathInfo.getHttpPath(), requestMappingClass.getName(), method.getName()); } ControllerMethod controllerMethod = new ControllerMethod(requestMappingClass, method, methodParams); this.pathControllerMethodMap.put(requestPathInfo, controllerMethod); } } } } @Override public boolean process(RequestProcessorChain requestProcessorChain) throws Exception { //1.解析HttpServletRequest的申请办法,申请门路，获取对应的ControllerMethod实例 String method = requestProcessorChain.getRequestMethod(); String path = requestProcessorChain.getRequestPath(); ControllerMethod controllerMethod = this.pathControllerMethodMap.get(new RequestPathInfo(method, path)); if (controllerMethod == null) { requestProcessorChain.setResultRender(new ResourceNotFoundResultRender(method, path)); return false; } //2.解析申请参数，并传递给获取到的ControllerMethod实例去执行 Object result = invokeControllerMethod(controllerMethod, requestProcessorChain.getRequest()); //3.依据解决的后果，抉择对应的render进行渲染 setResultRender(result, controllerMethod, requestProcessorChain); return true; } /** * 依据不同状况设置不同的渲染器 */ private void setResultRender(Object result, ControllerMethod controllerMethod, RequestProcessorChain requestProcessorChain) { if (result == null) { return; } ResultRender resultRender; boolean isJson = controllerMethod.getInvokeMethod().isAnnotationPresent(ResponseBody.class); if (isJson) { resultRender = new JsonResultRender(result); } else { resultRender = new ViewResultRender(result); } requestProcessorChain.setResultRender(resultRender); } private Object invokeControllerMethod(ControllerMethod controllerMethod, HttpServletRequest request) { //1.从申请里获取GET或者POST的参数名及其对应的值 Map<String, String> requestParamMap = new HashMap<>(); //GET，POST办法的申请参数获取形式 Map<String, String[]> parameterMap = request.getParameterMap(); for (Map.Entry<String, String[]> parameter : parameterMap.entrySet()) { if (!ValidationUtil.isEmpty(parameter.getValue())) { //只反对一个参数对应一个值的模式 requestParamMap.put(parameter.getKey(), parameter.getValue()[0]); } } //2.依据获取到的申请参数名及其对应的值，以及controllerMethod外面的参数和类型的映射关系，去实例化出办法对应的参数 List<Object> methodParams = new ArrayList<>(); Map<String, Class<?>> methodParamMap = controllerMethod.getMethodParameters(); for (String paramName : methodParamMap.keySet()) { Class<?> type = methodParamMap.get(paramName); String requestValue = requestParamMap.get(paramName); Object value; //只反对String 以及根底类型char,int,short,byte,double,long,float,boolean,及它们的包装类型 if (requestValue == null) { //将申请里的参数值转成适配于参数类型的空值 value = ConverterUtil.primitiveNull(type); } else { value = ConverterUtil.convert(type, requestValue); } methodParams.add(value); } //3.执行Controller外面对应的办法并返回后果 Object controller = beanContainer.getBean(controllerMethod.getControllerClass()); Method invokeMethod = controllerMethod.getInvokeMethod(); invokeMethod.setAccessible(true); Object result; try { if (methodParams.size() == 0) { result = invokeMethod.invoke(controller); } else { result = invokeMethod.invoke(controller, methodParams.toArray()); } } catch (InvocationTargetException e) { //如果是调用异样的话，须要通过e.getTargetException() // 去获取执行办法抛出的异样 throw new RuntimeException(e.getTargetException()); } catch (IllegalAccessException e) { throw new RuntimeException(e); } return result; }}5.2 ControllerRequestProcessor相干代码解说
6. ConverterUtil值转换工具类的补充
相干代码如下:
package com.wuyiccc.helloframework.util;/** * @author wuyiccc * @date 2020/7/15 8:02 * 岂曰无衣，与子同袍~ */public class ConverterUtil { /** * 返回根本数据类型的空值 * 须要非凡解决的根本类型即int\double\short\long\byte\float\boolean * * @param type 参数类型 * @return 对应的空值 */ public static Object primitiveNull(Class<?> type) { if (type == int.class || type == double.class || type == short.class || type == long.class || type == byte.class || type == float.class) { return 0; } else if (type == boolean.class) { return false; } return null; } /** * String类型转换成对应的参数类型 * * @param type 参数类型 * @param requestValue 值 * @return 转换后的Object */ public static Object convert(Class<?> type, String requestValue) { if (isPrimitive(type)) { if (ValidationUtil.isEmpty(requestValue)) { return primitiveNull(type); } if (type.equals(int.class) || type.equals(Integer.class)) { return Integer.parseInt(requestValue); } else if (type.equals(String.class)) { return requestValue; } else if (type.equals(Double.class) || type.equals(double.class)) { return Double.parseDouble(requestValue); } else if (type.equals(Float.class) || type.equals(float.class)) { return Float.parseFloat(requestValue); } else if (type.equals(Long.class) || type.equals(long.class)) { return Long.parseLong(requestValue); } else if (type.equals(Boolean.class) || type.equals(boolean.class)) { return Boolean.parseBoolean(requestValue); } else if (type.equals(Short.class) || type.equals(short.class)) { return Short.parseShort(requestValue); } else if (type.equals(Byte.class) || type.equals(byte.class)) { return Byte.parseByte(requestValue); } return requestValue; } else { throw new RuntimeException("count not support non primitive type conversion yet"); } } /** * 断定是否根本数据类型(包含包装类以及String) * * @param type 参数类型 * @return 是否为根本数据类型 */ private static boolean isPrimitive(Class<?> type) { return type == boolean.class || type == Boolean.class || type == double.class || type == Double.class || type == float.class || type == Float.class || type == short.class || type == Short.class || type == int.class || type == Integer.class || type == long.class || type == Long.class || type == String.class || type == byte.class || type == Byte.class || type == char.class || type == Character.class; }}github地址：https://github.com/wuyiccc/he...