创建Servlet的几种方式+web.xml中关于servlet的一些配置+浏览器、服务器交互Postman测试

呱

发布于 2020-10-23 10:34:57

1.3K0

发布于 2020-10-23 10:34:57

文章被收录于专栏：后端JavaEE

1.继承Servlet接口,重写servlet方法

package d01;

import javax.servlet.*;
import java.io.IOException;
import java.util.Date;

/**
 * zt
 * 2020/8/28
 * 10:53
 */
public class MyServlet implements Servlet {
    /**
     * 初始化servlet，只执行一次
     * @param servletConfig
     * @throws ServletException
     */
    @Override
    public void init(ServletConfig servletConfig) throws ServletException {
        System.out.println("初始化，呱？"+this.hashCode());
    }

    /**
     * 获取servlet配置
     * @return
     */
    @Override
    public ServletConfig getServletConfig() {
        System.out.println("获取servlet配置，呱？");
        return null;
    }

    /**
     * 服务方法，处理浏览器请求的方法
     * @param request 请求对象：封装请求信息
     * @param response 响应对象：封装响应信息
     * @throws ServletException
     * @throws IOException
     */
    @Override
    public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
        // 请求和响应乱码问题解决
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        //控制台打印
        System.out.println("service"+new Date());
        //输出数据给浏览器
        response.getWriter().write("hello 呱？");
    }

    /**
     * 获取servlet基本信息，版本，作者等
     * @return
     */
    @Override
    public String getServletInfo() {
        System.out.println("getServletInfo:"+hashCode());
        return null;
    }

    /**
     * 销毁，tomcat关闭的时候执行
     */
    @Override
    public void destroy() {
        System.out.println("destroy:"+hashCode());
    }
}

2.继承HttpServlet类，重写doget、dopost方法

直接输入myServlet2，会访问doGet方法 直接输入Demo1.htlm，店家按钮，会访问doPost方法

package d01;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * zt
 * 2020/8/28
 * 11:33
 */
public class MyServlet2 extends HttpServlet {
    /**
     * 处理get请求（浏览器直接输入地址）
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("doget执行了0.0呱？");

        /*// 请求和响应乱码问题解决
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        //输出数据给浏览器
        response.getWriter().write("hello 呱？");*/
    }

    /**
     * 处理post请求
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
        System.out.println("dopost执行了0.0呱？");

    }
}

运行结果

F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\bin\catalina.bat run
[2020-08-28 11:44:50,298] Artifact 0828:war exploded: Waiting for server connection to start artifact deployment...
Using CATALINA_BASE:   "C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828"
Using CATALINA_HOME:   "F:\Tomcat\Tomcat9\apache-tomcat-9.0.11"
Using CATALINA_TMPDIR: "F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\temp"
Using JRE_HOME:        "C:\Program Files\Java\jdk1.8.0_221"
Using CLASSPATH:       "F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\bin\bootstrap.jar;F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\bin\tomcat-juli.jar"
28-Aug-2020 11:44:52.831 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server version:        Apache Tomcat/9.0.11
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server built:          Aug 11 2018 19:47:23 UTC
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server number:         9.0.11.0
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name:               Windows 10
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version:            10.0
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture:          amd64
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home:             C:\Program Files\Java\jdk1.8.0_221\jre
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version:           1.8.0_221-b11
28-Aug-2020 11:44:52.834 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor:            Oracle Corporation
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE:         C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME:         F:\Tomcat\Tomcat9\apache-tomcat-9.0.11
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828\conf\logging.properties
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote=
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.port=1099
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.ssl=false
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.password.file=C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828\jmxremote.password
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.access.file=C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828\jmxremote.access
28-Aug-2020 11:44:52.835 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.rmi.server.hostname=127.0.0.1
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dignore.endorsed.dirs=
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=C:\Users\49841\.IntelliJIdea2019.3\system\tomcat\Tomcat_9_0_11_0828
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=F:\Tomcat\Tomcat9\apache-tomcat-9.0.11
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\temp
28-Aug-2020 11:44:52.836 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded APR based Apache Tomcat Native library [1.2.17] using APR version [1.6.3].
28-Aug-2020 11:44:52.837 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
28-Aug-2020 11:44:52.837 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true]
28-Aug-2020 11:44:53.907 信息 [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL successfully initialized [OpenSSL 1.0.2o  27 Mar 2018]
28-Aug-2020 11:44:54.043 信息 [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
28-Aug-2020 11:44:54.065 信息 [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
28-Aug-2020 11:44:54.074 信息 [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
28-Aug-2020 11:44:54.076 信息 [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
28-Aug-2020 11:44:54.077 信息 [main] org.apache.catalina.startup.Catalina.load Initialization processed in 1669 ms
28-Aug-2020 11:44:54.118 信息 [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
28-Aug-2020 11:44:54.119 信息 [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/9.0.11
28-Aug-2020 11:44:54.138 信息 [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
28-Aug-2020 11:44:54.151 信息 [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["ajp-nio-8009"]
28-Aug-2020 11:44:54.155 信息 [main] org.apache.catalina.startup.Catalina.start Server startup in 78 ms
Connected to server
[2020-08-28 11:44:54,419] Artifact 0828:war exploded: Artifact is being deployed, please wait...
[2020-08-28 11:44:54,915] Artifact 0828:war exploded: Artifact is deployed successfully
[2020-08-28 11:44:54,915] Artifact 0828:war exploded: Deploy took 496 milliseconds
28-Aug-2020 11:45:04.141 信息 [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\webapps\manager]
28-Aug-2020 11:45:04.200 信息 [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [F:\Tomcat\Tomcat9\apache-tomcat-9.0.11\webapps\manager] has finished in [58] ms
doget执行了0.0呱？
doget执行了0.0呱？
dopost执行了0.0呱？

3.利用idea快捷创建servlet

创建后会自动生成doget和dopost方法

/**
 * zt
 * 2020/8/28
 * 14:09
 */
@WebServlet(name = "Servlet3")
public class MyServlet3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
        System.out.println("dopost执行了0.0呱？");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("doget执行了0.0呱？");
    }
}

4.servlet一些关于web.xml的配置

4.1servlet与servlet-mapping配置

4.2servlet加载时机：1.（默认）第一次访问servlet时创建（-1）。2.启动tomcat时创建（>=0）

4.3servlet参数（可以在自己创建的servlet中调用）(可写在初始化里面或者servlet的其他方法中)

servletConfig.getInitParameter("username2");

<init-param>
            <param-name>username2</param-name>
            <param-value>呱？</param-value>
</init-param>

web.xml全部代码

<?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">
<!--    配置-->
    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>d01.MyServlet</servlet-class>
        <!--        servlet参数-->
        <init-param>
            <param-name>username</param-name>
            <param-value>zhuxi</param-value>
        </init-param>
        <init-param>
            <param-name>age</param-name>
            <param-value>18</param-value>
        </init-param>
<!--        servlet加载时机：1.（默认）第一次访问servlet时创建，2.启动tomcat时创建-->
<!--        1.（默认）第一次访问servlet时创建-->
<!--        <load-on-startup>-1</load-on-startup>-->
<!--        2.启动tomcat时创建-->
        <load-on-startup>0</load-on-startup>

    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/myServlet</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>MyServlet2</servlet-name>
        <servlet-class>d01.MyServlet2</servlet-class>
        <!--        servlet参数-->
        <init-param>
            <param-name>username2</param-name>
            <param-value>呱？</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet2</servlet-name>
        <url-pattern>/myServlet2</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>MyServlet3</servlet-name>
        <servlet-class>d01.MyServlet3</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet3</servlet-name>
        <url-pattern>/myServlet3</url-pattern>
<!--        <url-pattern>*.do</url-pattern>-->
<!--        匹配所有不包括jsp-->
<!--        <url-pattern>/</url-pattern>-->
<!--        匹配所有-->
<!--        <url-pattern>/*</url-pattern>-->
    </servlet-mapping>
</web-app>

5.利用注解配置servlet (与web.xml中类似)

package d01;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * zt
 * 2020/8/28
 * 15:19
 */
//1. name （servlet名称） 相当于web.xml的 <servlet-name>MyServlet</servlet-name>  ， 注解中的名字可要可不要
// 2.1 value 配置访问路径
// 2.2 url-patterns 配置访问路径
// 3.loadonstartup (servlet创建时机)
// 4.initParams设置servlet参数 （没有意义，直接写在下面即可）initParams = {@WebInitParam(name="大明",value="498999698@qq.com")}
@WebServlet(value = {"/login","login2"},loadOnStartup = 0,initParams = {@WebInitParam(name="大明",value="498999698@qq.com")})
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("使用注解配置servlet");
        String name = getInitParameter("大明");
        System.out.println(name);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

6.浏览器、服务器交互

package d02;

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.PrintWriter;

/**
 * zt
 * 2020/8/28
 * 16:05
 */
@WebServlet(value = "/res")
public class RegistServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1. 请求和响应乱码问题解决
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        //2. request封装浏览器发送的请求信息
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        //3. 其他方法
        System.out.println("获取请求头:"+request.getHeader("Accept"));
        System.out.println("请求方式:"+request.getMethod());
        System.out.println("getRequestURI统一资源标识符（包含定位符）"+request.getRequestURI());
        System.out.println("getRequestURL统一资源定位符"+request.getRequestURL());
        System.out.println("getRemoteAddr"+request.getRemoteAddr());

        //1.获取字节流(二进制数据（图片、声音或者文本）发给浏览器，使用ServletOutputStream)
//        ServletOutputStream outputStream = response.getOutputStream();
        //2.获取字符流，把文本数据发给浏览器(不能同时用)
        PrintWriter writer = response.getWriter();
        writer.write("hello,呱？");


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

浏览器运行结果：

服务器运行结果：

用户名：null
密码：null
获取请求头:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
请求方式:GET
getRequestURI统一资源标识符（包含定位符）/0828_war_exploded/res
getRequestURL统一资源定位符http://localhost:8080/0828_war_exploded/res
getRemoteAddr0:0:0:0:0:0:0:1

此时的用户名密码为null，是可以通过get与post方式传递的
get方式：直接在浏览器地址栏输入http://localhost:8080/0828_war_exploded/res?username=123&password=123
post方式：在postman中测试，如下图：

本文参与腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。

原始发表：2020/08/28 ，如有侵权请联系 cloudcommunity@tencent.com 删除

servlet

本文分享自作者个人站点/博客前往查看

如有侵权，请联系 cloudcommunity@tencent.com 删除。

本文参与腾讯云自媒体同步曝光计划，欢迎热爱写作的你一起参与！

登录后参与评论

0 条评论

热度

创建Servlet的几种方式+web.xml中关于servlet的一些配置+浏览器、服务器交互Postman测试

创建Servlet的几种方式+web.xml中关于servlet的一些配置+浏览器、服务器交互Postman测试

1.继承Servlet接口,重写servlet方法

2.继承HttpServlet类，重写doget、dopost方法

3.利用idea快捷创建servlet

4.servlet一些关于web.xml的配置

4.1servlet与servlet-mapping配置

4.2servlet加载时机：1.（默认）第一次访问servlet时创建（-1）。2.启动tomcat时创建（>=0）

4.3servlet参数（可以在自己创建的servlet中调用）(可写在初始化里面或者servlet的其他方法中)

web.xml全部代码

5.利用注解配置servlet (与web.xml中类似)

6.浏览器、服务器交互

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐