敲一个servlet项目

首先
pom.xml引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <packaging>war</packaging>
    <groupId>com.bw</groupId>
    <artifactId>exe_servlet_12.25</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <!-- mysql  -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <!--  servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <!-- 指定端口 -->
                    <port>8080</port>
                    <!-- 请求路径 -->
                    <path>/</path>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

这个是项目的一个分布
敲一个servlet项目
web.xml
导servlet
里面有路径

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <servlet>
        <servlet-name>exe_servlet_12.25</servlet-name>
        <servlet-class>com.bw.servlet.DemoServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>exe_servlet_12.25</servlet-name>
        <url-pattern>/demoServlet</url-pattern>
    </servlet-mapping>
</web-app>

demoServlet class类里面

继承 HttpServlet
实现里面的方法
doPost()    doGet()     init()         destory()
//声明一个变量
 PrintWriter printWriter = resp.getWriter();
  printWriter.print("Hello word!!!");
这个是用来打印在浏览器上面的