spring boot——整合JPA——入門示例002
阿新 • • 發佈：2022-05-29
pom檔案：
<?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> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.7.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.ch</groupId> <artifactId>ch6_1</artifactId> <version>0.0.1-SNAPSHOT</version> <name>ch6_1</name> <description>Demo project forSpring Boot</description> <properties> <java.version>11</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-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- 新增MySQL依賴 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.45</version> <!-- MySQL8.x時，請使用8.x的聯結器 --> </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>
application.properties如下：
server.servlet.context-path=/ch6_1 ### ##資料來源資訊配置 ### #資料庫地址 spring.datasource.url=jdbc:mysql://localhost:3306/springbootjpa?characterEncoding=utf8 #資料庫MySQL為8.x時，url為jdbc:mysql://localhost:3306/springbootjpa?useSSL=false&serverTimezone=Asia/Beijing&characterEncoding=utf-8#資料庫使用者名稱 spring.datasource.username=root #資料庫密碼 spring.datasource.password=root #資料庫驅動 spring.datasource.driver-class-name=com.mysql.jdbc.Driver #資料庫MySQL為8.x時，驅動類為com.mysql.cj.jdbc.Driver #### #JPA持久化配置 #### #指定資料庫型別 spring.jpa.database=MYSQL #指定是否在日誌中顯示SQL語句 spring.jpa.show-sql=true #指定自動建立、更新資料庫表等配置，update表示如果資料庫中存在持久化類對應的表就不建立，不存在就建立對應的表 spring.jpa.hibernate.ddl-auto=update #讓控制器輸出的JSON字串格式更美觀 spring.jackson.serialization.indent-output=true
整體如下：
MyUser
package com.ch.ch6_1.entity; import java.io.Serializable; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "user_table") /** * 如果沒寫表名，預設為類名的片語 * （如MyUser類對應的表名為my_user） */ public class MyUser implements Serializable{ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id;//主鍵 /**使用@Column註解，可以配置列相關屬性（列名，長度等）， * 可以省略，預設為屬性名小寫 */ private String uname; private String usex; private int age; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUname() { return uname; } public void setUname(String uname) { this.uname = uname; } public String getUsex() { return usex; } public void setUsex(String usex) { this.usex = usex; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
UserRepository
package com.ch.ch6_1.repository; import java.util.List; import org.springframework.data.jpa.repository.JpaRepository; import com.ch.ch6_1.entity.MyUser; /** * 這裡不需要使用@Repository註解資料訪問層， * 因為Spring Boot自動配置了JpaRepository */ public interface UserRepository extends JpaRepository<MyUser, Integer>{ public MyUser findByUname(String uname); public List<MyUser> findByUnameLike(String uname); }
UserService
package com.ch.ch6_1.service; import java.util.List; import com.ch.ch6_1.entity.MyUser; public interface UserService { public void saveAll(); public List<MyUser> findAll(); public MyUser findByUname(String uname); public List<MyUser> findByUnameLike(String uname); public MyUser getOne(int id); }
UserServiceImpl
package com.ch.ch6_1.service; import java.util.ArrayList; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import com.ch.ch6_1.entity.MyUser; import com.ch.ch6_1.repository.UserRepository; @Service @Transactional public class UserServiceImpl implements UserService{ @Autowired private UserRepository userRepository;//依賴注入資料訪問層 @Override public void saveAll() { MyUser mu1 = new MyUser(); mu1.setUname("陳恆1"); mu1.setUsex("男"); mu1.setAge(88); MyUser mu2 = new MyUser(); mu2.setUname("陳恆2"); mu2.setUsex("女"); mu2.setAge(18); MyUser mu3 = new MyUser(); mu3.setUname("陳恆3"); mu3.setUsex("男"); mu3.setAge(99); List<MyUser> users = new ArrayList<MyUser>(); users.add(mu1); users.add(mu2); users.add(mu3); //呼叫父介面中的方法saveAll userRepository.saveAll(users); } @Override public List<MyUser> findAll() { //呼叫父介面中的方法findAll return userRepository.findAll(); } @Override public MyUser findByUname(String uname) { return userRepository.findByUname(uname); } @Override public List<MyUser> findByUnameLike(String uname) { return userRepository.findByUnameLike("%" + uname + "%"); } @Override public MyUser getOne(int id) { //呼叫父介面中的方法getOne return userRepository.getOne(id); } }
UserTestController
package com.ch.ch6_1.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import com.ch.ch6_1.service.UserService; @Controller public class UserTestController { @Autowired private UserService userService; @RequestMapping("/save") @ResponseBody public String save() { userService.saveAll(); return "儲存使用者成功！"; } @RequestMapping("/findByUname") public String findByUname(String uname, Model model) { model.addAttribute("title", "根據使用者名稱查詢一個使用者"); model.addAttribute("auser", userService.findByUname(uname)); return "showAuser"; } @RequestMapping("/getOne") public String getOne(int id, Model model) { model.addAttribute("title", "根據使用者id查詢一個使用者"); model.addAttribute("auser",userService.getOne(id)); return "showAuser"; } @RequestMapping("/findAll") public String findAll(Model model){ model.addAttribute("title", "查詢所有使用者"); model.addAttribute("allUsers",userService.findAll()); return "showAll"; } @RequestMapping("/findByUnameLike") public String findByUnameLike(String uname, Model model){ model.addAttribute("title", "根據使用者名稱模糊查詢所有使用者"); model.addAttribute("allUsers",userService.findByUnameLike(uname)); return "showAll"; } }