Java Web (一)——创建工程

Web

版本：1
作者：陈小默
声明：禁止商业，禁止转载

使用正式版IDEA(不是社区版)，创建一个普通的maven项目，然后补全目录为web应用目录。

添加 Java Web 的 Maven 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>
    <groupId>cxm</groupId>
    <artifactId>cxm</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <kotlin.version>1.0.5</kotlin.version>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.0</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.19.1</version>
            </plugin>
            <plugin>
                <groupId>org.jetbrains.kotlin</groupId>
                <artifactId>kotlin-maven-plugin</artifactId>
                <version>${kotlin.version}</version>
                <executions>
                    <execution>
                        <id>compile</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>test-compile</id>
                        <phase>test-compile</phase>
                        <goals>
                            <goal>test-compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/jsp-api -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib</artifactId>
            <version>${kotlin.version}</version>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test</artifactId>
            <version>${kotlin.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

在 IDEA 中配置 Tomcat

首先，我们小在IDEA中配置Tomcat，详细过程如下

1. 单击IDEA的Edit Configurations，弹出Run/Debug Configurations对话框。
2. 单击+按钮，选择Tomcat Service -> Local 选项。
3. 给当前服务器设置一个名字，比如smart，取消勾选After launch选项。
4. 单击Application Service下拉框的Configure按钮，配置一个Tomcat，配置完成后，在下拉框选择该Tomcat。
5. 切换到Deployment选项卡，单击+按钮，选择Artifact选项，弹出 Select Artifact to Deploy对话框。
6. 选择 chapter1:war exploded，然后在Application context中输入服务器名称/smart
7. 切换回Service选项卡，在On frame deactivation下拉框中选择Upload resources。

Hello Servlet

接下来我们使用一个简单的示例测试是否成功

创建一个Servlet

package com.github.cccxm.smart
import javax.servlet.http.HttpServlet
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse
/**
 * HelloServlet
 */
class HelloServlet : HttpServlet() {
    override fun doGet(req: HttpServletRequest, resp: HttpServletResponse) {
        val writer = resp.writer
        writer.write("hello servlet")
        writer.flush()
    }
}

修改web.xml文件

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
            http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0">
    <display-name>smart</display-name>
    <servlet>
        <servlet-name>HelloServlet</servlet-name>
        <servlet-class>com.github.cccxm.smart.HelloServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>HelloServlet</servlet-name>
        <url-pattern>/hello</url-pattern>
    </servlet-mapping>
</web-app>

然后点击运行按钮，等待服务器启动之后我们打开浏览器，输入http://127.0.0.1:8080/smart/hello，访问后就能看见浏览器上打印了一句hello servlet