Spring Boot - Tomcat部署

通过使用Spring Boot应用程序，无涯教程可以创建一个war文件来部署到Web服务器中。在本章中，您将学习如何创建WAR文件以及如何在Tomcat Web服务器中部署Spring Boot应用程序。

Servlet初始化

传统的部署方式是使Spring Boot Application @SpringBootApplication类扩展SpringBootServletInitializer类。Spring Boot Servlet Initializer类文件允许您使用Servlet容器在启动应用程序时对其进行配置。

下面给出了用于JAR文件部署的Spring Boot Application类文件的代码-

package com.learnfk.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);
   }
}

无涯教程需要扩展 SpringBootServletInitializer 类以支持WAR文件部署。 Spring Boot Application类文件的代码如下-

package com.learnfk.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

@SpringBootApplication
public class DemoApplication  extends SpringBootServletInitializer {
   @Override
   protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
      return application.sources(DemoApplication.class);
   }
   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);
   }
}

设置Main Class

在Spring Boot中，需要提及应在构建文件中启动的主类。为此，您可以使用以下代码-

对于Maven，在 pom.xml 属性中添加起始类，如下所示-

<start-class>com.learnfk.demo.DemoApplication</start-class>

对于Gradle，在build.gradle中添加主类名称，如下所示-

mainClassName="com.learnfk.demo.DemoApplication"

将JAR更新为WAR

无涯教程必须使用以下代码将打包的JAR打包为WAR:对于Maven，将包装作为WAR添加到 pom.xml 中，如下所示-

<packaging>war</packaging>

对于Gradle，在 build.gradle 中添加应用程序插件和war插件，如下所示-

apply plugin:'war'
apply plugin:'application'

现在，让无涯教程编写一个简单的Rest Endpoint来返回字符串" Hello World from Tomcat"。要编写Rest Endpoint，需要将Spring Boot Web Starter依赖项添加到构建文件中。

对于Maven，使用如下所示的代码在pom.xml中添加Spring Boot启动器依赖项-

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
</dependency>

对于Gradle，使用如下所示的代码在 build.gradle 中添加Spring Boot启动器依赖项-

dependencies {
   compile('org.springframework.boot:spring-boot-starter-web')
}

现在，使用如下所示的代码在Spring Boot Application类文件中编写一个简单的Rest Endpoint-

package com.learnfk.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class DemoApplication  extends SpringBootServletInitializer {
   @Override
   protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
      return application.sources(DemoApplication.class);
   }
   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);
   }
   
   @RequestMapping(value = "/")
   public String hello() {
      return "Hello World from Tomcat";
   }
}

打包应用程序

现在，通过使用Maven和Gradle命令打包应用程序，创建一个WAR文件以部署到Tomcat服务器中，如下所示-

对于Maven，使用命令 mvn package 打包您的应用程序。然后，将创建WAR文件，您可以在目标目录中找到它，如下面所示-

对于Gradle，请使用命令 gradle clean build 打包您的应用程序。然后，将创建您的WAR文件，您可以在 build/libs 目录下找到它。观察此处给出的屏幕截图以更好地理解-

部署到Tomcat

现在，运行Tomcat服务器，并将WAR文件部署在 webapps 目录下。观察此处显示的屏幕截图，以更好地理解-

成功部署后，在Web浏览器 http://localhost:8080/demo-0.0.1-SNAPSHOT/中单击URL，并观察到输出将如下面所示-

下面给出了用于此目的的完整代码。

pom.xml

<?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.learnfk</groupId>
   <artifactId>demo</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>war</packaging>
   <name>demo</name>
   <description>Demo project for Spring Boot</description>
   
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.8.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
      <java.version>1.8</java.version>
      <start-class>com.learnfk.demo.DemoApplication</start-class>
   </properties>

   <dependencies>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>
   
</project>

build.gradle

buildscript {
   ext {
      springBootVersion = '1.5.8.RELEASE'
   }
   repositories {
      mavenCentral()
   }
dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'war'
apply plugin: 'application'

group = 'com.learnfk'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
mainClassName = "com.learnfk.demo.DemoApplication"

repositories {
   mavenCentral()
}
dependencies {
   compile('org.springframework.boot:spring-boot-starter-web')
   testCompile('org.springframework.boot:spring-boot-starter-test')
}

下面给出了主要的Spring Boot应用程序类文件的代码-

package com.learnfk.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class DemoApplication  extends SpringBootServletInitializer {
   @Override
   protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
      return application.sources(DemoApplication.class);
   }
   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);
   }
   
   @RequestMapping(value = "/")
   public String hello() {
      return "Hello World from Tomcat";
   }
}