初始化好工程之后

入門(mén)

新建一個(gè)HelloController.java

package com.example.girl1;import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController;@RestController public class HelloController {@RequestMapping(value = "/girl",method = RequestMethod.GET)public String say(){return "1111111";} }復(fù)制代碼

在瀏覽器中輸入localhost:8080/girl 內(nèi)容就是1111111

啟動(dòng)方式

1. idea直接啟動(dòng)

2. mvn

• mvn spring-boot:run

3. 打包成jar包啟動(dòng)

• mvn install
• cd target
• java -jar jar包名

項(xiàng)目屬性配置

resource 目錄下 將application.xxx修改成application.yml

server:port: 8080servlet:context-path: /first 復(fù)制代碼

之后訪問(wèn)就得 ：http://localhost:8080/first/girl

配置文件屬性的使用

server:port: 8080 cupSize: A復(fù)制代碼

HelloController.java中

@RestController public class HelloController {// 通過(guò)注解把配置文件中的cupSize注入到變量中@Value("${cupSize}")private String cupSize;@RequestMapping(value = "/girl",method = RequestMethod.GET)public String say(){return cupSize;} } 復(fù)制代碼

打開(kāi)瀏覽器就能看到cupSize了

屬性多的時(shí)候就加個(gè)前綴來(lái)區(qū)分

新建一個(gè)類(lèi) GirlProperties.java

package com.example.girl1;import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component;// 獲取前綴是girl的配置 @Component @ConfigurationProperties(prefix = "girl") public class GirlProperties {private String cupSize;private Integer age;public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public String getCupSize() {return cupSize;}public void setCupSize(String cupSize) {this.cupSize = cupSize;} }復(fù)制代碼

配置文件

server:port: 8080 girl:cupSize: Aage: 18 復(fù)制代碼

HelloController

@RestController public class HelloController {@Autowiredprivate GirlProperties girlProperties;@RequestMapping(value = "/girl",method = RequestMethod.GET)public Integer say(){return girlProperties.getAge();} } 復(fù)制代碼

這樣就能做到用前綴來(lái)區(qū)分，自己打開(kāi)瀏覽器看看就明白了

配置的開(kāi)發(fā)環(huán)境和生產(chǎn)環(huán)境

• application.yml

// application.ymlspring:profiles:active: dev 復(fù)制代碼

• application-dev.yml

server:port: 8080 girl:cupSize: Bage: 18復(fù)制代碼

• application-prod.yml

server:port: 8081 girl:cupSize: Aage: 20復(fù)制代碼

• 可以在idea中啟動(dòng)開(kāi)發(fā)環(huán)境，
• 在mvn install 后生成的jar包啟動(dòng)開(kāi)發(fā)環(huán)境

java -jar jar包名 --spring.profiles.active=prod 復(fù)制代碼

Controller的使用

• @Controller 處理http請(qǐng)求
• @RestController Spring4之后新加的注解，原來(lái)返回json需要@RequestBody配合@Controller(RestController相當(dāng)于這兩個(gè)的組合RequestBody和Controller)
• @RequestMapping 配置url映射

@RequestMapping

// 如果想訪問(wèn)兩個(gè) @RequestMapping(value = {"/girl","/hello"},method = RequestMethod.GET) 復(fù)制代碼// 可以給類(lèi)加，訪問(wèn)就得 ：localhost:8080/hello/girl了 @RestController @RequestMapping("/hello") public class HelloController {@Autowiredprivate GirlProperties girlProperties;@RequestMapping(value = {"/girl"},method = RequestMethod.GET)public Integer say(){return girlProperties.getAge();} } // RequestMethod方式有很多 可以使用postman來(lái)測(cè)試api 復(fù)制代碼

處理url里面的參數(shù)

• @PathVariable 獲取url里面的數(shù)據(jù)
• @RequestParam 獲取請(qǐng)求參數(shù)的值
• @GetMapping 組合注解

@PathVariable

@RestController public class HelloController {@Autowiredprivate GirlProperties girlProperties;@RequestMapping(value = {"/girl/{id}"},method = RequestMethod.GET)public Integer say(@PathVariable("id") Integer myId){return myId;} } // localhost:8080/girl/100 復(fù)制代碼

@RequestParam

//localhost:8080/girl?id=100 @RestController public class HelloController {@Autowiredprivate GirlProperties girlProperties;@RequestMapping(value = {"/girl"},method = RequestMethod.GET)public Integer say(@RequestParam("id") Integer myId){return myId;} } // 另一種寫(xiě)法 @RestController public class HelloController {@Autowiredprivate GirlProperties girlProperties;@RequestMapping(value = {"/girl"},method = RequestMethod.GET)// 默認(rèn)值和是否必須傳入public Integer say(@RequestParam(value = "id",required = false,defaultValue = "10") Integer myId){return myId;} } // RequestMapping 可以寫(xiě)成GetMapping 復(fù)制代碼

數(shù)據(jù)庫(kù)操作

在pom.xml導(dǎo)入包

// jpa和mysql的<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency> 復(fù)制代碼

結(jié)束后導(dǎo)入一下包

配置文件的配置

// 運(yùn)行前先新建一個(gè)dbgirl的數(shù)據(jù)庫(kù)，utf8mb4 // application.yml spring:profiles:active: devdatasource:driver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://127.0.0.1:3306/dbgirlusername: rootpassword: 123456jpa:hibernate:ddl-auto: update // create會(huì)把之前的表刪掉在新建一個(gè)show-sql: true 復(fù)制代碼

新建一個(gè)Girl類(lèi)

package com.example.girl1;import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; // 這個(gè)注解表示這個(gè)類(lèi)就是對(duì)應(yīng)數(shù)據(jù)庫(kù)中的表 @Entity public class Girl {@Id@GeneratedValueprivate Integer id;private String cupSize;private Integer age;public Girl() {}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getCupSize() {return cupSize;}public void setCupSize(String cupSize) {this.cupSize = cupSize;} } // 之后表中的那些字段就是girl類(lèi)中對(duì)應(yīng)過(guò)去的 復(fù)制代碼

接口編寫(xiě)

get /girls 獲取女生列表post /girls 創(chuàng)建一個(gè)女生get /girls/id 通過(guò)id查詢(xún)一個(gè)女生put /girls/id 通過(guò)id更新一個(gè)女生delete /girls/id 通過(guò)id刪除一個(gè)女生 復(fù)制代碼

獲取女生列表

新建一個(gè)GirlRepository.java的接口

package com.example.girl1;import org.springframework.data.jpa.repository.JpaRepository;// Girl類(lèi)名，Integer是id的類(lèi)型 public interface GirlRepository extends JpaRepository<Girl,Integer> {}復(fù)制代碼

新建GirlController.java

package com.example.girl1;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController;import java.util.List; @RestController public class GirlController {@Autowiredprivate GirlRepository girlRepository;/** 查詢(xún)女生列表* */@GetMapping(value = "/girls")public List<Girl> girlList(){return girlRepository.findAll();} } // 使用postman測(cè)試 復(fù)制代碼

創(chuàng)建一個(gè)女生

/** 新增一個(gè)女生* */@PostMapping(value = "/girls")public Girl girlAdd(@RequestParam("cupSize") String cupSize,@RequestParam("age") Integer age){Girl girl = new Girl();girl.setCupSize(cupSize);girl.setAge(age);return girlRepository.save(girl);} 復(fù)制代碼

通過(guò)id查詢(xún)一個(gè)女生

// 查詢(xún)一個(gè)女生@GetMapping(value = "/girls/{id}")public Girl girlFindOne(@PathVariable("id") Integer id){return girlRepository.findById(id).orElse(null);} 復(fù)制代碼

通過(guò)id更新一個(gè)女生

// 更新@PutMapping(value = "/girls/{id}")public Girl girlUpdate(@PathVariable("id") Integer id,@RequestParam("cupSize") String cupSize,@RequestParam("age") Integer age){Girl girl = new Girl();girl.setId(id);girl.setCupSize(cupSize);girl.setAge(age);return girlRepository.save(girl);} 復(fù)制代碼

通過(guò)id刪除一個(gè)女生

// 刪除@DeleteMapping(value = "/girls/{id}")public void girlDelete(@PathVariable("id") Integer id){girlRepository.deleteById(id);} 復(fù)制代碼

通過(guò)年齡查詢(xún)女生列表

// 通過(guò)年齡查詢(xún)女生列表@GetMapping(value = "/girls/age/{age}")public List<Girl> girlListByAge(@PathVariable("age") Integer age){return girlRepository.findByAge(age);} 復(fù)制代碼

GirlRepository.java中

package com.first.first;import org.springframework.data.jpa.repository.JpaRepository;import java.util.List;public interface GirlRepository extends JpaRepository<Girl,Integer> {// 通過(guò)年齡查詢(xún)public List<Girl> findByAge(Integer age); }復(fù)制代碼

事務(wù)管理

需求是如果我有兩條數(shù)據(jù)，一條插入失敗的話(huà)另一條就不能插入，這時(shí)候需要加一個(gè)事務(wù)

GirlService.java

package com.example.girl1;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional;@Service public class GirlService {@Autowiredprivate GirlRepository girlRepository;@Transactionalpublic void insertTwo(){Girl girlA= new Girl();girlA.setAge(10);girlA.setCupSize("B");girlRepository.save(girlA);Girl girlB= new Girl();girlA.setAge(11);girlA.setCupSize("F");girlRepository.save(girlB);} }// 在Girlcontroller里新增@Autowiredprivate GirlService girlService;@PostMapping(value = "/girls/two")public void girlTwo(){girlService.insertTwo();}復(fù)制代碼

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