Servlet_서블릿 매핑 HttpServletRequest로 요청 처리하기

- servlet

--- servlet-api

1) 프로젝트 우클릭 > Build Path > Classpath

    - Add External JARs... > servlet-api.jar 파일 추가하기 

 

- 브라우저에서 요청하는 기본적인 방법

http:// [ IP주소 ] : [ 포트 번호 ] / [ 프로젝트 이름 ] / [ 패키지 이름이 포함된 클래스 이름 ]

 

서블릿 매핑 > web.xml 파일에 설정합니다.

<servlet>
	<servlet-name> [ servlet-mapping에서 설정한 servlet-name ]</servlet-name>
    <servlet-class> [ 실제 기능을 수행하는 클래스 경로 ] </servlet-class>
</servlet>

<servlet-mapping>
	<servlet-name> [ 서블릿 이름 ] </servlet-name>
    <url-pattern> [ 웹 브라우저에서 요청하는 이름 ] </url-pattern>
</servlet-mapping>

 

>>>

http:// [ IP 주소 ] / [ 프로젝트 이름 ] / [웹 브라우저에서 요청하는 이름]

 

- 주의사항 : 여러 개의 서블릿 매핑을 진행하는 경우 servlet끼리 위치시킵니다.

- 서블릿은 메모리에 존재하는 서블릿을 재사용함으로 빠르고 효율적으로 동작합니다.

- 서블릿 클래스 : HttpServlet 상속

 

2) 어노테이션으로 매핑하기

@WebServlet(" / [ 웹 브라우저에서 요청하는 이름 ] ") : 서블릿 클래스 위에 선언합니다.

 

- 주의사항 : 어노테이션으로 매핑하는 경우 반드시 HttpServlet을 상속받아야 합니다.

 

- 주의사항 : web.xml 파일에서 설정한 매핑 이름과 어노테이션으로 설정한 매핑 이름이 동일한 경우 오류 발생

A child container failed during start

ExecutionException 

 

 

===== 실습 환경 =====

1. New > Spring Legacy Project 생성

--- Project Name : servletProject

--- Template : Spring MVC Project

 

--- package : com.basic.servlet

 

 

2. Java 버전 변경

프로젝트 우클릭 > Properties > Project Facet 

 

 

3. pom.xml 파일 수정

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<?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 https://maven.apache.org/maven-v4_0_0.xsd">     <modelVersion>4.0.0</modelVersion>     <groupId>com.basic</groupId>     <artifactId>servlet</artifactId>     <name>servletProject</name>     <packaging>war</packaging>     <version>1.0.0-BUILD-SNAPSHOT</version>     <properties>         <java-version>11</java-version>         <org.springframework-version>5.3.27</org.springframework-version>         <org.aspectj-version>1.9.19</org.aspectj-version>         <org.slf4j-version>2.0.7</org.slf4j-version>     </properties>     <dependencies>         <!-- Spring -->         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-context</artifactId>             <version>${org.springframework-version}</version>             <exclusions>                 <!-- Exclude Commons Logging in favor of SLF4j -->                 <exclusion>                     <groupId>commons-logging</groupId>                     <artifactId>commons-logging</artifactId>                  </exclusion>             </exclusions>         </dependency>         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-webmvc</artifactId>             <version>${org.springframework-version}</version>         </dependency>                          <!-- AspectJ -->         <dependency>             <groupId>org.aspectj</groupId>             <artifactId>aspectjrt</artifactId>             <version>${org.aspectj-version}</version>         </dependency>                      <!-- Logging -->         <dependency>             <groupId>org.slf4j</groupId>             <artifactId>slf4j-api</artifactId>             <version>${org.slf4j-version}</version>         </dependency>         <dependency>             <groupId>org.slf4j</groupId>             <artifactId>jcl-over-slf4j</artifactId>             <version>${org.slf4j-version}</version>             <scope>runtime</scope>         </dependency>         <dependency>             <groupId>org.slf4j</groupId>             <artifactId>slf4j-log4j12</artifactId>             <version>${org.slf4j-version}</version>             <scope>runtime</scope>         </dependency>         <dependency>             <groupId>log4j</groupId>             <artifactId>log4j</artifactId>             <version>1.2.15</version>             <exclusions>                 <exclusion>                     <groupId>javax.mail</groupId>                     <artifactId>mail</artifactId>                 </exclusion>                 <exclusion>                     <groupId>javax.jms</groupId>                     <artifactId>jms</artifactId>                 </exclusion>                 <exclusion>                     <groupId>com.sun.jdmk</groupId>                     <artifactId>jmxtools</artifactId>                 </exclusion>                 <exclusion>                     <groupId>com.sun.jmx</groupId>                     <artifactId>jmxri</artifactId>                 </exclusion>             </exclusions>             <scope>runtime</scope>         </dependency>           <!-- @Inject -->         <dependency>             <groupId>javax.inject</groupId>             <artifactId>javax.inject</artifactId>             <version>1</version>         </dependency>                                   <!-- Servlet --> <!-- Servlet : 기본값         <dependency>             <groupId>javax.servlet</groupId>             <artifactId>servlet-api</artifactId>             <version>2.5</version>             <scope>provided</scope>         </dependency>         <dependency>             <groupId>javax.servlet.jsp</groupId>             <artifactId>jsp-api</artifactId>             <version>2.1</version>             <scope>provided</scope>         </dependency> --> <!-- javax.servlet-api : servlet-api 대신 사용 -->                  <dependency>             <groupId>javax.servlet</groupId>             <artifactId>javax.servlet-api</artifactId>             <version>4.0.0</version>             <scope>provided</scope>         </dependency>          <!-- javax.servlet.jsp-api : jsp-api 대신 사용 -->         <dependency>             <groupId>javax.servlet.jsp</groupId>             <artifactId>javax.servlet.jsp-api</artifactId>             <version>2.3.3</version>             <scope>provided</scope>         </dependency>                  <dependency>             <groupId>javax.servlet</groupId>             <artifactId>jstl</artifactId>             <version>1.2</version>         </dependency>              <!-- Test -->         <dependency>             <groupId>junit</groupId>             <artifactId>junit</artifactId>             <version>4.13.2</version>             <scope>test</scope>         </dependency>            <!-- project 기본 설정 끝 -->               </dependencies>     <build>         <plugins>             <plugin>                 <artifactId>maven-eclipse-plugin</artifactId>                 <version>2.9</version>                 <configuration>                     <additionalProjectnatures>                         <projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>                     </additionalProjectnatures>                     <additionalBuildcommands>                         <buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>                     </additionalBuildcommands>                     <downloadSources>true</downloadSources>                     <downloadJavadocs>true</downloadJavadocs>                 </configuration>             </plugin>   <!-- maven-compiler-plugin : 버전 변경 -->             <plugin>                 <groupId>org.apache.maven.plugins</groupId>                 <artifactId>maven-compiler-plugin</artifactId>                 <version>3.10.1</version>                 <configuration>                     <source>11</source>                     <target>11</target>                     <compilerArgument>-Xlint:all</compilerArgument>                     <showWarnings>true</showWarnings>                     <showDeprecation>true</showDeprecation>                 </configuration>             </plugin>              <!-- exec-maven-plugin : 버전 변경 -->             <plugin>                 <groupId>org.codehaus.mojo</groupId>                 <artifactId>exec-maven-plugin</artifactId>                 <version>3.1.0</version>                 <configuration>                     <mainClass>org.test.int1.Main</mainClass>                 </configuration>             </plugin>         </plugins>     </build> </project>

 

 

 

4. src > main > webapp > form.html html 파일 생성

 

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Form.html</title>
</head>
<body>
    <form name="formtag" method="get" action="formtag">
        Input Data 1 : <input type="text" name="data1"> <br> 
        Input Data 2 : <input type="text" name="data2"> <br> 
        <input type="submit" value="Submit">
        <input type="reset" value="Reset">
    </form>
</body>
</html>

 

 

 

5. src/main/java > com.basic.servlet > FormServlet.java 클래스 생성

 

package com.basic.servlet;
 
import java.io.IOException;
 
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
@WebServlet("/formtag")
public class FormServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
 
    @Override
    public void init() throws ServletException{
        System.out.println("[ FormServlet ] : init()");
    }
    
    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("[ FormServlet ] : doGet()");
        
        request.setCharacterEncoding("UTF-8");
        String data1 = request.getParameter("data1");
        String data2 = request.getParameter("data2");
        
        System.out.println("Data 1 : " + data1);
        System.out.println("Data 2 : " + data2);
    }
    
    @Override
    public void destroy() {
        System.out.println("[ FormServlet ] : destroy()");
    }
}
 

 

 

6. 실행하기

1) 웹 브라우저에 http://localhost:8080/servlet/form.html 

 

2) Submit buttom 클릭

 

응답 화면을 작성하지 않았으므로 브라우저에서는 보여지지 않지만 콘솔창에서 출력됩니다.