从零写一个具有IOC-AOP-MVC功能的框架-学习笔记-11. MVC功能之http请求处理器的编写-简易框架最后...
1. 本章需要完成的内容：
- 完成ControllerRequestProcessor类的编写： Controller请求处理器
- 完成JspRequestProcessor类的编写：jsp资源请求处理
- 完成PreRequestProcessor类的编写： 请求预处理,包括编码以及路径处理
- 完成StaticResourceRequestProcessor类的编写： 静态资源请求处理，包括但不限于图片，css，以及js文件等, 转发到DefaultServlet
2. PreRequestProcessor类的编写
2.1 PreRequestProcessor类需要完成的代码
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;
/**
* 请求预处理,包括编码以及路径处理
*/
@Slf4j
public class PreRequestProcessor implements RequestProcessor {
@Override
public boolean process(RequestProcessorChain requestProcessorChain) throws Exception {
// 1.设置请求编码，将其统一设置成UTF-8
requestProcessorChain.getRequest().setCharacterEncoding("UTF-8");
// 2.将请求路径末尾的/剔除，为后续匹配Controller请求路径做准备
// （一般Controller的处理路径是/aaa/bbb，所以如果传入的路径结尾是/aaa/bbb/，
// 就需要处理成/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类相关代码讲解：
3. StaticResourceRequestProcessor类的编写
3.1 StaticResourceRequestProcessor类需要完成的代码:
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~
*/
@Slf4j
public class StaticResourceRequestProcessor implements RequestProcessor {
public static final String DEFAULT_TOMCAT_SERVLET = "default";
public static final String STATIC_RESOURCE_PREFIX = "/static/";
//tomcat默认请求派发器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.通过请求路径判断是否是请求的静态资源 webapp/static
if (isStaticResource(requestProcessorChain.getRequestPath())) {
//2.如果是静态资源，则将请求转发给default servlet处理
defaultDispatcher.forward(requestProcessorChain.getRequest(), requestProcessorChain.getResponse());
return false;
}
return true;
}
//通过请求路径前缀（目录）是否为静态资源 /static/
private boolean isStaticResource(String path) {
return path.startsWith(STATIC_RESOURCE_PREFIX);
}
}
3.2 StaticResourceRequestProcessor类相关代码讲解：
4. JspRequestProcessor
4.1 JspRequestProcessor需要完成的代码：
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资源请求处理
*/
public class JspRequestProcessor implements RequestProcessor {
//jsp请求的RequestDispatcher的名称
private static final String JSP_SERVLET = "jsp";
//Jsp请求资源路径前缀
private static final String JSP_RESOURCE_PREFIX = "/templates/";
/**
* jsp的RequestDispatcher,处理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;
}
/**
* 是否请求的是jsp资源
*/
private boolean isJspResource(String url) {
return url.startsWith(JSP_RESOURCE_PREFIX);
}
}
4.2 JspRequestProcessor相关代码讲解：
5. ControllerRequestProcessor类的编写
5.1 ControllerRequestProcessor需要完成的代码:
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请求处理器
*/
@Slf4j
public class ControllerRequestProcessor implements RequestProcessor {
//IOC容器
private BeanContainer beanContainer;
//请求和controller方法的映射集合
private Map<RequestPathInfo, ControllerMethod> pathControllerMethodMap = new ConcurrentHashMap<>();
/**
* 依靠容器的能力，建立起请求路径、请求方法与Controller方法实例的映射
*/
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，获取类上面该注解的属性值作为一级路径
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标记的方法，获取方法上面该注解的属性值，作为二级路径
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.解析方法里被@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，建立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方法里面所有的参数都需要@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，放置到映射表里
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的请求方法,请求路径，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.解析请求参数，并传递给获取到的ControllerMethod实例去执行
Object result = invokeControllerMethod(controllerMethod, requestProcessorChain.getRequest());
//3.根据处理的结果，选择对应的render进行渲染
setResultRender(result, controllerMethod, requestProcessorChain);
return true;
}
/**
* 根据不同情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.从请求里获取GET或者POST的参数名及其对应的值
Map<String, String> requestParamMap = new HashMap<>();
//GET，POST方法的请求参数获取方式
Map<String, String[]> parameterMap = request.getParameterMap();
for (Map.Entry<String, String[]> parameter : parameterMap.entrySet()) {
if (!ValidationUtil.isEmpty(parameter.getValue())) {
//只支持一个参数对应一个值的形式
requestParamMap.put(parameter.getKey(), parameter.getValue()[0]);
}
}
//2.根据获取到的请求参数名及其对应的值，以及controllerMethod里面的参数和类型的映射关系，去实例化出方法对应的参数
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;
//只支持String 以及基础类型char,int,short,byte,double,long,float,boolean,及它们的包装类型
if (requestValue == null) {
//将请求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里面对应的方法并返回结果
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) {
//如果是调用异常的话，需要通过e.getTargetException()
// 去获取执行方法抛出的异常
throw new RuntimeException(e.getTargetException());
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
return result;
}
}
5.2 ControllerRequestProcessor相关代码讲解
6. ConverterUtil值转换工具类的补充
相关代码如下:
package com.wuyiccc.helloframework.util;
/**
* @author wuyiccc
* @date 2020/7/15 8:02
* 岂曰无衣，与子同袍~
*/
public class ConverterUtil {
/**
* 返回基本数据类型的空值
* 需要特殊处理的基本类型即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");
}
}
/**
* 判定是否基本数据类型(包括包装类以及String)
*
* @param type 参数类型
* @return 是否为基本数据类型
*/
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...
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文章和留言都翻到11页了 没有OOM
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朋友，翻页到11页，及以后，会出现OOM，无法访问
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搞个gitee的项目
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版本号是多少，你可以下载哪个代码仓库，jdk选1.8 直接跑就行
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