一、簡介
Restful是一種對url進行規范的編碼風格，通常一個網址對應一個資源，訪問形式類似http://xxx.com/xx/{id}/{id}。
舉個栗子，當我們在某購物網站上買手機時會有很多品牌選擇，而每種品牌下又有很多型號，那么https://mall.com/mobile/iphone/6 代表了Iphone6，https://mall.com/mobile/iphone/7和https://mall.com/mobile/iphone/8分別代表了Iphone7和Iphone8。
SpringBoot內置了SpringMvc中，也提供了@RequestParam, @RequestBody和@PathVariable 三個注解獲取客戶端參數，其中前兩者獲取的是客戶端post提交的參數，而@PathVariable 則是從訪問url中獲取參數。
言歸正傳，下面我們以用戶管理系統為例，在SpringBoot中編寫一組Restful風格的接口吧。
二、開發環境
- IDE：IntelliJ IDEA
- 官網地址：https://www.jetbrains.com/idea/download/
- JDK：1.8
- 數據庫：MySQL
- 構建工具：Maven
三、編寫自己的Restful程序
1.創建SpringBoot項目，如下圖所示：
點擊Next，選擇一些基本項目參數，如下圖：
點擊Next，選擇我們需要的組件，這里我們選擇MySQL，JPA，WEB組件作為我們開發組件。如下圖所示:
點擊Finish即完成項目的創建，項目結構如下圖:
2.項目依賴Maven配置pom.xml如下：
<?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.forMelo</groupId> <artifactId>myrestfulproject</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <name>myrestfulproject</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <!--<scope>provided</scope>--> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <optional>true</optional> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
3.數據源、JPA配置
SpringBoot默認配置文件為application.properties，我們將其修改為application.yml格式，.yml屬性文件層次感和可讀性更強。application.yml具體配置如下：
spring: datasource: url: jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8 driverClassName: com.mysql.jdbc.Driver username: root password: 1 jpa: database: MySQL show-sql: true hibernate: ddl-auto: update naming-strategy: org.hibernate.cfg.ImprovedNamingStrategy
下面我們在mysql中創建test數據庫，使用SQLyog創建表t_user_info，如下圖所示：
4.編寫控制器UserController.java和實體類User.java
UserController.java
package com.formelo.controller; import com.formelo.entity.User; import com.formelo.repository.UserJPARepository; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import java.util.List; /** * Created by songqiuming on 2018/1/7. */ @RestController public class UserController { @Autowired private UserJPARepository userJPARepository; /** * 查詢用戶列表 * @return */ @GetMapping(value = "/user") public List<User> findUserList(){ return userJPARepository.findAll(); } /** * 根據Id查詢一個用戶 * @param id * @return */ @GetMapping(value = "/user/query/{id}") public User findUserOne(@PathVariable("id") Integer id){ return userJPARepository.findOne(id); } /** * 添加用戶 * @param name * @param age * @param country * @return */ @PostMapping(value = "/user") public User addUser(@RequestParam("name") String name, @RequestParam("age") int age, @RequestParam("country") String country){ User user = new User(); user.setName(name); user.setAge(age); user.setCountry(country); return userJPARepository.save(user); } /** * 刪除用戶 * @param id 用戶編號 * @return */ @DeleteMapping(value = "/user/{id}") public List<User> deleteUser(@PathVariable("id") Integer id){ userJPARepository.delete(id); return userJPARepository.findAll(); } /** * 更新用戶 * @param id * @param name * @param age * @param country * @return */ @PutMapping(value = "/user/{id}") public User updateUser(@PathVariable("id") Integer id, @RequestParam("name") String name, @RequestParam("age") int age, @RequestParam("country") String country){ User user = userJPARepository.findById(id); user.setName(name); user.setAge(age); user.setCountry(country); return userJPARepository.save(user); } /** * 根據國家查詢用戶 * @param country * @return */ @GetMapping(value = "/user/{country}") public List<User> findByCountry(@PathVariable("country") String country){ return userJPARepository.findByCountry(country); } }
User.java
package com.formelo.entity; import javax.persistence.*; /** * Created by songqiuming on 2018/1/7. */ @Entity @Table(name = "t_user_info") public class User { private static final long serialVersionUID = -3039703447657705408L; @Id @GeneratedValue @Column(name = "id") private Long id; @Column(name = "name") private String name; @Column(name="age") private int age; @Column(name="country") private String country; public User() { } public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } @Override public String toString() { return "User{" + "id=" + id + ", name='" + name + '\'' + ", age=" + age + ", country='" + country + '\'' + '}'; } }
5.創建JPA
創建UserJPARepository.java，它繼承SpringDataJPA內的JpaRepository接口，實現與數據庫的交互。
UserJPARepository.java
package com.formelo.repository; import com.formelo.entity.User; import org.springframework.data.jpa.repository.JpaRepository; import java.util.List; /** * Created by songqiuming on 2018/1/7. */ public interface UserJPARepository extends JpaRepository<User,Long> { User findById(Long id); List<User> findByCountry(String country); }
6.啟動項目
到處為止，我們已經完成一組restful風格接口的編碼，運行MyrestfulprojectApplication的main方法，啟動項目，控制台輸出：
"C:\Program Files\Java\jdk1.8.0_102\bin\java" ... . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.5.9.RELEASE) 2018-01-09 21:57:41.533 INFO 6884 --- [ main] com.formelo.MyrestfulprojectApplication : Starting MyrestfulprojectApplication on DESKTOP-6SJA93T with PID 6884 (D:\myproject\myrestfulproject\target\classes started by songqiuming in D:\myproject\myrestfulproject) 2018-01-09 21:57:41.560 INFO 6884 --- [ main] com.formelo.MyrestfulprojectApplication : No active profile set, falling back to default profiles: default 2018-01-09 21:57:41.763 INFO 6884 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@65466a6a: startup date [Tue Jan 09 21:57:41 CST 2018]; root of context hierarchy 2018-01-09 21:57:47.897 INFO 6884 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http) 2018-01-09 21:57:47.969 INFO 6884 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2018-01-09 21:57:47.972 INFO 6884 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.23 2018-01-09 21:57:48.358 INFO 6884 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2018-01-09 21:57:48.359 INFO 6884 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 6609 ms 2018-01-09 21:57:48.663 INFO 6884 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] 2018-01-09 21:57:48.669 INFO 6884 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*] 2018-01-09 21:57:48.670 INFO 6884 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] 2018-01-09 21:57:48.670 INFO 6884 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*] 2018-01-09 21:57:48.670 INFO 6884 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*] 2018-01-09 21:57:49.598 INFO 6884 --- [ main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default' 2018-01-09 21:57:49.656 INFO 6884 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [ name: default ...] 2018-01-09 21:57:49.817 INFO 6884 --- [ main] org.hibernate.Version : HHH000412: Hibernate Core {5.0.12.Final} 2018-01-09 21:57:49.819 INFO 6884 --- [ main] org.hibernate.cfg.Environment : HHH000206: hibernate.properties not found 2018-01-09 21:57:49.820 INFO 6884 --- [ main] org.hibernate.cfg.Environment : HHH000021: Bytecode provider name : javassist 2018-01-09 21:57:49.976 INFO 6884 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.0.1.Final} Tue Jan 09 21:57:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:51 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:51 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:51 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:51 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. Tue Jan 09 21:57:51 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification. 2018-01-09 21:57:51.225 INFO 6884 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.MySQL5Dialect 2018-01-09 21:57:52.092 INFO 6884 --- [ main] org.hibernate.tool.hbm2ddl.SchemaUpdate : HHH000228: Running hbm2ddl schema update 2018-01-09 21:57:52.229 INFO 6884 --- [ main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default' 2018-01-09 21:57:53.483 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@65466a6a: startup date [Tue Jan 09 21:57:41 CST 2018]; root of context hierarchy 2018-01-09 21:57:53.666 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user],methods=[POST]}" onto public com.formelo.entity.User com.formelo.controller.UserController.addUser(java.lang.String,int,java.lang.String) 2018-01-09 21:57:53.667 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/{country}],methods=[GET]}" onto public java.util.List<com.formelo.entity.User> com.formelo.controller.UserController.findByCountry(java.lang.String) 2018-01-09 21:57:53.669 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/{id}],methods=[DELETE]}" onto public java.util.List<com.formelo.entity.User> com.formelo.controller.UserController.deleteUser(java.lang.Long) 2018-01-09 21:57:53.669 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/{id}],methods=[GET]}" onto public com.formelo.entity.User com.formelo.controller.UserController.findUserOne(java.lang.Long) 2018-01-09 21:57:53.670 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user/{id}],methods=[PUT]}" onto public com.formelo.entity.User com.formelo.controller.UserController.updateUser(java.lang.Long,java.lang.String,int,java.lang.String) 2018-01-09 21:57:53.670 INFO 6884 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/user],methods=[GET]}" onto public java.util.List<com.formelo.entity.User> com.formelo.controller.UserController.findUserList() 2018-01-09 21:57:53.673 INFO 6884 --- [ 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) 2018-01-09 21:57:53.674 INFO 6884 --- [ 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) 2018-01-09 21:57:53.761 INFO 6884 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2018-01-09 21:57:53.762 INFO 6884 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2018-01-09 21:57:53.945 INFO 6884 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2018-01-09 21:57:54.419 INFO 6884 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup 2018-01-09 21:57:54.520 INFO 6884 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http) 2018-01-09 21:57:54.525 INFO 6884 --- [ main] com.formelo.MyrestfulprojectApplication : Started MyrestfulprojectApplication in 14.573 seconds (JVM running for 16.939)
7.接口測試
下面我們打開postman測試接口。首先，往數據庫里插入幾條數據，對應的請求如下：
- 查詢用戶列表
根據ID查詢一個用戶：
添加用戶:
更新用戶：
