简单Servlet的get/post请求获取参数

一.通过maven创建一个servlet项目

二。将创建好的项目转化为web项目

三，pom文件

<?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>

    <groupId>com.huawei</groupId>
    <artifactId>servlet_demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <!-- JUnit配置 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <!-- 添加Servlet -->
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <!--3.1版本后，不需要web.xml配置访问，直接注解@WebServlet(urlPatterns = "/hello")过去-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.68</version>
        </dependency>

        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
    </dependencies>

</project>

五。ServletDemo

package com.huawei;

import org.apache.commons.io.IOUtils;

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;

@WebServlet(urlPatterns = "/hello")
public class ServletDemo extends HttpServlet {

   @Override
   protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //get请求获取参数
//       String hello = req.getParameter("hello");
//       System.out.println(hello);

       //post请求获取参数
       String result = IOUtils.toString(req.getInputStream(), "UTF-8");
       System.out.println(result);

   }
}

六，web.xml(servlet-api3.1之前需要在这里配置访问路径，注释那个)

<?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_4_0.xsd"
         version="4.0">
    <!--<servlet>
        <servlet-name>HelloServlet</servlet-name>
        <servlet-class>com.huawei.ServletDemo</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>HelloServlet</servlet-name>
        <url-pattern>/hello</url-pattern>
    </servlet-mapping>-->
</web-app>