Spring Boot - Tomcat部署

通过使用Spring Boot应用程序，我们可以创建一个war文件以部署到Web服务器中。在本章中，您将学习如何创建WAR文件并在Tomcat Web服务器中部署Spring Boot应用程序。

Spring Boot Servlet初始化程序

传统的部署方式是使Spring Boot Application @SpringBootApplication类扩展SpringBootServletInitializer类。Spring Boot Servlet Initializer类文件允许您在使用Servlet Container启动时配置应用程序。

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

package com.codingdict.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);
   }
}

我们需要扩展类SpringBootServletInitializer以支持WAR文件部署。Spring Boot Application类文件的代码如下

package com.codingdict.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.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);
   }
}

设置主类

在Spring Boot中，我们需要提到应该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start类，如下所示

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

对于Gradle，在build.gradle中添加主类名，如下所示

mainClassName="com.codingdict.demo.DemoApplication"

将打包JAR更新为WAR

我们必须使用以下代码将包装JAR更新为WAR

对于Maven，在pom.xml中将包装添加为WAR，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，让我们编写一个简单的Rest Endpoint来返回字符串“Tomcat中的Hello World”。要编写Rest端点，我们需要将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启动程序依赖项

<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 starter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.codingdict.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.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";
   }
}

打包您的应用程序

现在，使用Maven和Gradle命令创建一个WAR文件以部署到Tomcat服务器中，以打包您的应用程序，如下所示

对于Maven，使用命令mvn package打包应用程序。然后，将创建WAR文件，您可以在目标目录中找到它，如下面给出的屏幕截图所示

屏幕截图1

屏幕截图2

对于Gradle，使用命令gradle clean build打包应用程序。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便更好地理解

屏幕截图1

屏幕截图2

部署到Tomcat

现在，运行Tomcat服务器，并在webapps目录下部署WAR文件。观察此处显示的屏幕截图以便更好地理解

部署到Tomcat

部署到Tomcat

成功部署后，点击网页浏览器中的URL http://localhost:8080/demo-0.0.1-SNAPSHOT/，观察输出结果如下面的截图所示

截图所示

用于此目的的完整代码如下。

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.codingdict</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.codingdict.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.codingdict'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
mainClassName = "com.codingdict.demo.DemoApplication"

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

主Spring Boot应用程序类文件的代码如下

package com.codingdict.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.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";
   }
}