1. 本章须要实现的内容

1. 实现申请处理器接口RequestProcessor的编写
2. 实现ResultRender渲染器接口的编写
3. 实现DefultResultRender默认渲染器类的编写
4. 实现InternalErrorResultRender外部异样渲染器类的编写
5. 实现JsonResultRender Json渲染器类的编写
6. 实现ResourceNotFoundResultRender 资源未找到时应用的渲染器类编写
7. 实现ViewResultRender 页面渲染器类的编写
8. 实现DispatcherServlet http申请拦截器的编写
9. 实现RequestProcessorChain 责任链类的编写

2. 第一局部内容

1. 该局部实现DispatcherServlet与RequestProcessorChain类的编写

2.1 DispatcherServlet类

2.1.1 须要实现的代码如下：

package com.wuyiccc.helloframework.mvc;import com.wuyiccc.helloframework.aop.AspectWeaver;import com.wuyiccc.helloframework.core.BeanContainer;import com.wuyiccc.helloframework.injection.DependencyInjector;import com.wuyiccc.helloframework.mvc.processor.RequestProcessor;import com.wuyiccc.helloframework.mvc.processor.impl.ControllerRequestProcessor;import com.wuyiccc.helloframework.mvc.processor.impl.JspRequestProcessor;import com.wuyiccc.helloframework.mvc.processor.impl.PreRequestProcessor;import com.wuyiccc.helloframework.mvc.processor.impl.StaticResourceRequestProcessor;import lombok.extern.slf4j.Slf4j;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.InputStream;import java.util.ArrayList;import java.util.List;import java.util.Properties;/** * @author wuyiccc * @date 2020/7/14 21:42 * 岂曰无衣，与子同袍~ */@WebServlet("/*")@Slf4jpublic class DispatcherServlet extends HttpServlet {    private static final String HELLOFRAMEWORK_CONFIG_FILE = "config/helloframework-config.properties";    private List<RequestProcessor> PROCESSOR = new ArrayList<>();    @Override    public void init() throws ServletException {        // 1. 初始化容器        BeanContainer beanContainer = BeanContainer.getInstance();        beanContainer.loadBeans(getHelloFrameworkScanPackages());        new AspectWeaver().doAop();        new DependencyInjector().doIoc();        // 2. 初始化申请处理器责任链        PROCESSOR.add(new PreRequestProcessor());        PROCESSOR.add(new StaticResourceRequestProcessor(getServletContext()));        PROCESSOR.add(new JspRequestProcessor(getServletContext()));        PROCESSOR.add(new ControllerRequestProcessor());    }    @Override    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        // 1. 创立责任链对象实例        RequestProcessorChain requestProcessorChain = new RequestProcessorChain(PROCESSOR.iterator(), req, resp);        // 2. 通过责任链模式来顺次调用申请处理器对申请进行解决        requestProcessorChain.doRequestProcessorChain();        // 3. 对处理结果进行渲染        requestProcessorChain.doRender();    }    private String getHelloFrameworkScanPackages() {        Properties properties = new Properties();        InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(HELLOFRAMEWORK_CONFIG_FILE);        try {            properties.load(in);        } catch (IOException e) {            log.warn("The config/helloframework.properties can not load");            e.printStackTrace();        }        String scanPackages = properties.getProperty("helloframework.scan.packages");        log.info("this is scanPackages: {}", scanPackages);        return scanPackages;    }}

2.1.2 DIspatcherServlet类相干代码解说：

2.2 RequestProcessorChain类

2.2.1 须要实现的代码如下:

package org.myframework.mvc;/** * @author wuyiccc * @date 2020/6/16 18:48 * 岂曰无衣，与子同袍~ */import lombok.Data;import lombok.extern.slf4j.Slf4j;import org.myframework.mvc.processor.RequestProcessor;import org.myframework.mvc.render.DefaultResultRender;import org.myframework.mvc.render.InternalErrorResultRender;import org.myframework.mvc.render.ResultRender;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.util.Iterator;/** * 1. 以责任链的模式执行注册的申请处理器 * 2. 委派给特定的Render实例对解决后的后果进行渲染 */@Data@Slf4jpublic class RequestProcessorChain {    // 申请处理器迭代器    private Iterator<RequestProcessor> requestProcessorIterator;    private HttpServletRequest request;    private HttpServletResponse response;    // http申请办法    private String requestMethod;    // http申请门路    private String requestPath;    // http响应状态码    private int responseCode;    // 申请后果渲染器    private ResultRender resultRender;    public RequestProcessorChain(Iterator<RequestProcessor> requestProcessorIterator, HttpServletRequest request, HttpServletResponse response) {        this.requestProcessorIterator = requestProcessorIterator;        this.request = request;        this.response = response;        this.requestMethod = request.getMethod();        this.requestPath = request.getPathInfo();        this.responseCode = HttpServletResponse.SC_OK;    }    /**     * 以责任链的模式执行申请链     */    public void doRequestProcessorChain() {        // 1. 通过迭代器遍历注册的申请处理器实现类列表        try {            while (requestProcessorIterator.hasNext()) {                // 2. 晓得某个申请处理器执行后返回为false为止                if (!requestProcessorIterator.next().process(this)) {                    break;                }            }        } catch (Exception e) {            // 3. 期间如果出现异常，则交给外部异样渲染器解决            this.resultRender = new InternalErrorResultRender(e.getMessage());            log.error("doRequestProcessorChain error: ", e);        }    }    /**     * 执行处理器     */    public void doRender() {        // 1. 如果申请处理器实现类均未抉择适合的渲染器，则应用默认的        if (this.resultRender == null) {            this.resultRender = new DefaultResultRender();        }        // 2. 调用渲染器的render办法对后果进行渲染        try {            this.resultRender.render(this);        } catch (Exception e) {            log.error("doRender error: ", e);            throw new RuntimeException(e);        }    }}

3. 第二局部须要实现的内容： 后果渲染器的编写

3.1 DefaultResultRender类的编写及解说：

3.2 InternalErrorResultRender类的编写及解说：

3.3 JsonResultRender类的编写及解说:

3.4 ResourceNotFoundResultRender类的编写及解说:

3.5 ViewResultRender类的编写及解说：

github地址：https://github.com/wuyiccc/he...