手写嵌入式Tomcat(带详细注解)

落日映苍穹つ 2021-10-18 11:44 392阅读 0赞

## 导读 ##

**本文分为两部分**  
1. 实现思路分析部分  
2. 实现代码部分

## 一. 实现思路分析 ##

**使用Tomcat的API实现, 步骤如下**

1.  新建一个Tomcat对象
2.  设置Tomccat的端口号
3.  设置Context目录
4.  添加Servlet容器
5.  调用Tomcat对象start()
6.  强制Tomcat等待

## **二.实现代码** ##

**MyTomcatServer**  
代码如下

public class MyTomcatServer {
    
        public static void main(String[] args) throws Exception {
            // 把目录的绝对路径获取到
            String classpath = System.getProperty("user.dir");
            System.out.println(classpath);
            Tomcat tomcat = new Tomcat();
            // 设置Tomcat的端口
            Connector connector = tomcat.getConnector();
            connector.setPort(9091);
            // 设置Host
            Host host = tomcat.getHost();
            host.setName("localhost");
            host.setAppBase("webapps");
            // 加载class
            Context context = tomcat.addContext(host, "/",classpath);
            if (context instanceof StandardContext){
                StandardContext standardContext = (StandardContext) context;
                // 加载自己的web.xml配置文件
                standardContext.setDefaultContextXml("D:/workAPP/apache-tomcat-8.5.39-windows-x64/apache-tomcat-8.5.39/conf/web.xml");
                // 设置Servlet
                Wrapper wrapper = tomcat.addServlet("/", "MyServlet", new MyServlet());
                // 设置访问路径
                wrapper.addMapping("/lilei");
            }
    
            // Tomcat启动
            tomcat.start();
            // 强制Tomcat server等待, 避免main线程执行结束后关闭
            tomcat.getServer().await();
        }
    }

**Servlet代码如下:**

public class MyServlet implements Servlet {
        @Override
        public void init(ServletConfig servletConfig) throws ServletException {
            System.out.println("ok!!");
        }
    
        @Override
        public ServletConfig getServletConfig() {
            return null;
        }
    
        @Override
        public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
            HttpServletResponse response = (HttpServletResponse) servletResponse;
            response.setCharacterEncoding("UTF-8");
            response.setHeader("content-type","text/html;charset=UTF-8");
            PrintWriter writer = response.getWriter();
            writer.write("<h1>ok!!! <b>李磊加油!!</h1>");
            writer.close();
        }
    
        @Override
        public String getServletInfo() {
            return null;
        }
    
        @Override
        public void destroy() {
    
        }
    }

## 三. 结束 ##

感谢读者朋友的阅读! 前路愿与大家一同探索!!!