【Spring Boot && Spring Cloud系列】构建Springboot项目 实现restful风格接口

项目代码如下：

 package hello;

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

 @SpringBootApplication  // same as @Configuration @EnableAutoConfiguration @ComponentScan

 public class Application {

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

 }

 package hello;

 public class Greeting {
 private  long id;
 private  String content;
 public Greeting(long id, String content) {
     super();
     this.id = id;
     this.content = content;
 }
 public long getId() {
     return id;
 }
 public void setId(long id) {
     this.id = id;
 }
 public String getContent() {
     return content;
 }
 public void setContent(String content) {
     this.content = content;
 }

 }

 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 // shorthand for @Controller and @ResponseBody rolled together
 public class GreetingController {

     private static final String template="Hello,%s!";
     private final AtomicLong counter=new AtomicLong();

     @RequestMapping("/greeting")
     public Greeting greeting(@RequestParam(value="name",defaultValue="World")String name){
         System.out.println("-------------------------");
         return new Greeting(counter.incrementAndGet(),String.format(template, name));
     }
 }

 <?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.slp</groupId>
     <artifactId>restSpringDemo1</artifactId>
     <version>0.1.0</version>

     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.4.1.RELEASE</version>
     </parent>

     <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>
         <dependency>
             <groupId>com.jayway.jsonpath</groupId>
             <artifactId>json-path</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>

     <properties>
         <java.version>1.8</java.version>
     </properties>

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

     <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>

在Application.java中run as java application 出现：

  .   ____          _            __ _ _
  /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
 ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
  \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
   '  |____| .__|_| |_|_| |_\__, | / / / /
  =========|_|==============|___/=/_/_/_/
  :: Spring Boot ::        (v1.4.1.RELEASE)

 2016-10-13 11:19:16.510  INFO 9864 --- [           main] hello.Application                        : Starting Application on QH-20160418YQMB with PID 9864 (started by sanglp in D:\rest风格的apring项目\restSpringDemo1)
 2016-10-13 11:19:16.525  INFO 9864 --- [           main] hello.Application                        : No active profile set, falling back to default profiles: default
 2016-10-13 11:19:16.713  INFO 9864 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@72f926e6: startup date [Thu Oct 13 11:19:16 CST 2016]; root of context hierarchy
 2016-10-13 11:19:19.691  INFO 9864 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
 2016-10-13 11:19:19.710  INFO 9864 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
 2016-10-13 11:19:19.710  INFO 9864 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.0.35
 2016-10-13 11:19:20.148  INFO 9864 --- [ost-startStop-1] org.apache.jasper.servlet.TldScanner     : At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
 2016-10-13 11:19:20.148  INFO 9864 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
 2016-10-13 11:19:20.148  INFO 9864 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 3451 ms
 2016-10-13 11:19:20.382  INFO 9864 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
 2016-10-13 11:19:20.398  INFO 9864 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
 2016-10-13 11:19:20.398  INFO 9864 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
 2016-10-13 11:19:20.398  INFO 9864 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
 2016-10-13 11:19:20.398  INFO 9864 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
 2016-10-13 11:19:20.866  INFO 9864 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@72f926e6: startup date [Thu Oct 13 11:19:16 CST 2016]; root of context hierarchy
 2016-10-13 11:19:20.986  INFO 9864 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/greeting]}" onto public hello.Greeting hello.GreetingController.greeting(java.lang.String)
 2016-10-13 11:19:20.986  INFO 9864 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
 2016-10-13 11:19:20.986  INFO 9864 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
 2016-10-13 11:19:21.033  INFO 9864 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
 2016-10-13 11:19:21.033  INFO 9864 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
 2016-10-13 11:19:21.095  INFO 9864 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
 2016-10-13 11:19:21.307  INFO 9864 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
 2016-10-13 11:19:21.463  INFO 9864 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
 2016-10-13 11:19:21.479  INFO 9864 --- [           main] hello.Application                        : Started Application in 6.497 seconds (JVM running for 7.83)
 2016-10-13 11:21:46.570  INFO 9864 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
 2016-10-13 11:21:46.570  INFO 9864 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
 2016-10-13 11:21:46.622  INFO 9864 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 51 ms

表示启动成功，这是就可以访问了 http://localhost:8080/greeting?name=xxb

会出现如下结果：

{"id":3,"content":"Hello,xuxiaobo!"}

这是一个纯java的项目，不需要启动tomcat也可以执行访问

首先你需要建立一个基本的项目，你可以使用任何你喜欢的方式去构造Spring项目，这里使用的是Maven.如果你不熟悉Maven的话请移步 Building Java Projects with Maven.

创建项目目录结构

在你所选的项目目录中，创建如下的子目录结构；例如在unix系统中使用mkdir -p src/main/java/hello。

└── src
    └── main
        └── java
            └── hello

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>org.springframework</groupId>
    <artifactId>gs-rest-service</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.1.RELEASE</version>
    </parent>

    <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>
        <dependency>
            <groupId>com.jayway.jsonpath</groupId>
            <artifactId>json-path</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

    <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>

Spring Boot的maven插件提供了很多便利的特性：

• 它包含了路径中的所有jar文件，使用“über-jar”。它使得执行和转换服务非常便利。

• 它查询 public static void main() 方法去标志为一个可执行的类

• 它提供了一个内置的匹配Spring boot 依赖的版本，你可以选择任何你希望的版本，但是默认情况下它会选择Boot的版本设置变量。