文章内容概述:
spring项目组其实有多个projects,如spring IO platform用于管理external dependencies的版本,通过定义BOM(bill of materials)来管理所引入的external dependencies的版本,从而避免版本冲突问题,再如spring web flow项目,专门为构建流形式的web application提供支持。除了刚刚所叙述的这两个project之外,spring社区还有若干其他project,分别可应用于不同application的开发。Spring协会的这些project都是基于spring framework来创建的,所以支持spring框架的特色功能。同时,它们又对spring framework的modules以及项目可能依赖的三方库、插件等做了基本的封装,在这些project的基础上进行自己的项目的开发,会比直接基于spring framework创建自己的project更便捷。
我们想要搭建的机器学习管理平台是用于提供restful web services,综合考虑spring社区各个projects的特点,决定舍弃原来的决定,由直接基于the spring framework搭建自己的web网站改为基于spring boot来搭建自己的网站,希望由此简化整个开发过程。
具体操作:
step1,了解spring boot的特点,参见官网documentation
step2, 参照 官网guids 以及 git上的sample工程 向项目中引入spring boot
step2.1 修改pom.xml,包括
注释掉之前引入的spring framework的modules相关的配置,以及
添加spring boot相关的配置
项目最终的pom.xml如下
-
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>bupt.jinmensuyin.webapp</groupId>
<artifactId>leapmotion-web</artifactId>
<packaging>war</packaging>
<version>0.0.1</version>
<name>leapmotion-web Maven Webapp</name> <!--spring boot中定义了pom.xml,
该pom.xml中引入了spring framework的若干 modules如spring-core、spring-context等,
还引入了三方插件如spring-boot-maven-plugin等
还引入了spring framework的external dependencies...
所以将spring-boot-starter-parent这个pom.xml作为自己的project的parent POM
这样一来,就可以简化自己项目的pom.xml的配置-->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
</parent>
<dependencies>
<!-- 引入spring-boot中的若干模块作为自己的项目的external 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>
<!-- 使用Jackson JSON library完成自己工程中编写的POJO类向JSON字符串的自动转化
如下面步骤中,可以将Greeting类实例自动转化成JSON字符串(其实就是自动将该POJO类对象的属性串成JSON格式的字符串)
-->
<dependency>
<groupId>com.jayway.jsonpath</groupId>
<artifactId>json-path</artifactId>
<scope>test</scope>
</dependency>
<!-- 单元测试相关的lib,提供用于单元测试的相关API
用于白盒测试,即程序员知道被测试的软件如何(How)完成功能和完成什么样(What)的功能的情况下编写的测试代码
根据Junit所定义的规则进行编写相关测试代码(如测试代码必须继承特定的类等等),可以实现“自动测试”
对不同性质的被测对象,如Class,Jsp,Servlet,Ejb等,Junit有不同的使用技巧-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<!--20161221:lxrm
修改:将下面的这些external dependencies注释掉
注释原因:研究了Spring协会旗下的所有projects之后,决定在spring boot这个project的基础上搭建自己的网站,
而不是直接依赖于spring framework来开发自己的网站,以期能够减少工作量,加快网站搭建进程 ,
所以将下面的external dependencies注释掉,改为引进spring boot
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
</dependency>
--> </dependencies> <build>
<finalName>leapmotion-web</finalName>
<!-- 注释原因:没注释之前,报错,错误原因是parent pom中已经指定过一次该插件,将此处配置注释掉以后不再报错
spring-boot-maven-plugin的功能有很多,具体包括:
It collects all the jars on the classpath and builds a single, runnable "über-jar",
which makes it more convenient to execute and transport your service.
It searches for the public static void main() method to flag as a runnable class.
It provides a built-in dependency resolver that sets the version number
to match Spring Boot dependencies. You can override any version you wish,
but it will default to Boot’s chosen set of versions.
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
-->
</build> <dependencyManagement>
<dependencies>
<!-- BOM:bill of materials,是一个external dependency的列表,该列表中确定了各个external dependency的版本
并且保证各个dependencies之间不会出现版本冲突问题 -->
<dependency>
<groupId>io.spring.platform</groupId>
<artifactId>platform-bom</artifactId>
<version>Athens-SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement> <repositories>
<repository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</pluginRepository>
</pluginRepositories> </project>
-
step3,编写java程序,测试spring boot是否成功引入
- 参考教程:
- 1)spring官网guids
- 2)spring官网sample工程
- 3)博客:Spring4 MVC REST SERVICES---使用@RestController实例
- 代码:
- Greeting.java POJO类(domain/Model层)
- GreetingController.java (Controller层,有@RequestMapping之类的标注。In Spring’s approach to building RESTful web services, HTTP requests are handled by a controller. These components are easily identified by the
@RestController
annotation, and theGreetingController
below handlesGET
requests for/greeting
by returning a new instance of theGreeting
class:) - GreetingConfiguration.java (相当于配置文件 )
- GreetingInitializer.java(相当于配置文件:web.xml中所有与spring(springMVC)相关的配置)
-
/**
* @author lxrm
* @date 20161221
* @description:spring boot的入门程序:hello world程序
* @function:这个类是一个POJO类,属于Model层的对象
* */
package hello;
public class Greeting {
private final long id;
private final String content; public Greeting(long id,String content){
this.id=id;
this.content=content;
} public long getId(){
return this.id;
}
public Stirng getContent(){
return this.content;
}
}/**
* @author:lxrm
* @date:20161221
* @description:spring-boot使用实例: hello world程序
* @function:本程序作为Controller,接收请求,调用相关业务层组件来完成处理任务,并返回处理结果
* In Spring’s approach to building RESTful web services,
* HTTP requests are handled by a controller.
* These components are easily identified by the @RestController annotation,
* and the GreetingController below handles GET requests for /greeting
* by returning a new instance of the Greeting class:*/
package hello; import java.util.concurrent.atomic.AtomicLong;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController; @RestController
public class GreetingController {
private satic final String template="Hello,%s!";
private final AtomicLong counter=new AtomicLong(); /**About @RequestMapping annotation
* 1.The @RequestMapping annotation ensures that HTTP requests to
* /greeting are mapped to the greeting() method.
*
* 2.The above example does not specify GET vs. PUT, POST,
* and so forth, because @RequestMapping maps all HTTP operations by default.
* Use @RequestMapping(method=GET) to narrow this mapping.
*
**About @RequestParam annotation
* 1.@RequestParam 将请求中的参数name绑定到greeting()方法的参数name上.
* This query string parameter is explicitly marked as optional (required=true by default):
* if it is absent in the request, the defaultValue of "World" is used.*/
@RequestMapping("/greeting")
public Greeting greeting(@RequestParam(value="name", defaultValue="LXRM") String name) {
/*
* @return:创建一个Greeting对象并作为返回值返回
* */
return new Greeting(counter.incrementAndGet(),
String.format(template, name));
}
}/**
* @author lxrm
* @date 20161221
* @description:spring boot的入门程序:hello world程序
* @function:1)这个类使用@SpringBootApplication注解以及其子注解标签来使得your project中所添加的所有spring注解生效,
* 有了@SpringBootApplication注解以及其子注解标签(@Configuration、@EnableAutoConfiguration、@EnableWebMvc
* @ComponentScan),
* 就可以不用使用*.xml配置文件,从而使得 there wasn’t a single line of XML? No web.xml file either.
* 最终整个web application is 100% pure Java
* 2)这个类中添加了public static void main(String[] args)函数,这就使得整个project可以被打包成可执行的jar包,
* 该jar包中包含所有necessary dependencies, classes, and resources,可以被直接运行
* */
package hello; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
/**
* About @SpringBootApplication 注解
* @SpringBootApplication is a convenience annotation that adds all of the following:
* @Configuration tags the class as a source of bean definitions for the application context.
* @EnableAutoConfiguration tells Spring Boot to start adding beans based on classpath settings,
* other beans, and various property settings.
* @EnableWebMvc Normally you would add this annotion for a Spring MVC app,
* but Spring Boot adds it automatically when it sees spring-webmvc on the classpath.
* This flags the application as a web application and activates key behaviors
* such as setting up a DispatcherServlet.
* @ComponentScan(basePackage="包名") tells Spring to look for other components, configurations,
* and services in the the hello package, allowing it to find the controllers. */
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "hello")
public class GreetingConfiguration {
/**
* The main() method uses Spring Boot’s SpringApplication.run() method
* to launch an application. */
/*
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
*/
}/**
* @author lxrm
* @date 20161221
* @description spring boot框架下的第一个程序:helloWorld程序
* @function 1.替代在web.xml中定义的任何spring相关的配置
* 2.这个类的功能类似于web.xml配置文件的功能,传统web application 中是通过在web.xml中添加相应的配置
* 如web.xml配置与springMVC相关的DispacthServlet来拦截客户端传来的HTTP请求,并交由spring的controller类处理相关请求,
* 如配置spring注解相关的类,你的project中添加的与spring框架相关的注解才能被识别
* 3.spring 4版本中舍弃了*.xml配置文件,直接使用java程序来进行这些配置
* XxxConfiguration类使得spring注解生效
* XxxInitializer.java(本程序)使得XxxConfiguration类生效,并且配置web.xml中所配置的其他东西*/
package hello; import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer; public class GreetingInitializer extends AbstractAnnotationConfigDispatcherServletInitializer { @Override
protected Class<?>[] getRootConfigClasses() {
return new Class[] { GreetingConfiguration.class };
} @Override
protected Class<?>[] getServletConfigClasses() {
return null;
} @Override
protected String[] getServletMappings() {
return new String[] { "/" };
} }
- 参考教程: