详解Spring Boot实战之Rest接口开发及数据库基本操作

本文介绍了Spring Boot实战之Rest接口开发及数据库基本操作，分享给大家

1、修改pom.xml，添加依赖库,本文使用的是mysql

 <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency> 

2、修改配置文件application.properties，配置数据源及java持久层API相关信息

spring.datasource.url = jdbc:mysql://127.0.0.1:3306/springlearn
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.driverClassName = com.mysql.jdbc.Driver 

# 配置数据库
spring.jpa.database = MYSQL
# 查询时是否显示日志
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update
# Naming strategy
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect 

3、添加数据模型 UserInfo.java

package com.xiaofangtech.sunt.bean; 

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull; 

@Entity
@Table(name="t_user")
public class UserInfo {
  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private int id;
  @NotNull
  private String name; 

  private String password; 

  private String salt; 

  private String role; 

  public int getId() {
    return id;
  } 

  public void setId(int id) {
    this.id = id;
  } 

  public String getName() {
    return name;
  } 

  public void setName(String name) {
    this.name = name;
  } 

  public String getPassword() {
    return password;
  } 

  public void setPassword(String password) {
    this.password = password;
  } 

  public String getSalt() {
    return salt;
  } 

  public void setSalt(String salt) {
    this.salt = salt;
  } 

  public String getRole() {
    return role;
  } 

  public void setRole(String role) {
    this.role = role;
  }
} 

4、添加数据访问接口类 UserInfoRepository.java

package com.xiaofangtech.sunt.repository; 

import java.util.List; 

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository; 

import com.xiaofangtech.sunt.bean.UserInfo; 

public interface UserInfoRepository extends CrudRepository<UserInfo, Integer>{
  UserInfo findUserInfoById(int id);
  List<UserInfo> findUserInfoByRole(String role); 

  @Query(value = "select * from t_user limit ?1", nativeQuery =true)
  List<UserInfo> findAllUsersByCount(int count);
} 

5、添加UserController.java，添加用户信息的增删改查操作

package com.xiaofangtech.sunt.controller; 

import java.util.List; 

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; 

import com.xiaofangtech.sunt.bean.UserInfo;
import com.xiaofangtech.sunt.repository.UserInfoRepository;
import com.xiaofangtech.sunt.utils.ResultMsg;
import com.xiaofangtech.sunt.utils.ResultStatusCode; 

@RestController
@RequestMapping("user")
public class UserController {
  @Autowired
  private UserInfoRepository userRepositoy; 

  @RequestMapping("getuser")
  public Object getUser(int id)
  {
    UserInfo userEntity = userRepositoy.findUserInfoById(id);
    ResultMsg resultMsg = new ResultMsg(ResultStatusCode.OK.getErrcode(), ResultStatusCode.OK.getErrmsg(), userEntity);
    return resultMsg;
  } 

  @RequestMapping("getusers")
  public Object getUsers(String role)
  {
    List<UserInfo> userEntities = userRepositoy.findUserInfoByRole(role);
    ResultMsg resultMsg = new ResultMsg(ResultStatusCode.OK.getErrcode(), ResultStatusCode.OK.getErrmsg(), userEntities);
    return resultMsg;
  } 

  @Modifying
  @RequestMapping("adduser")
  public Object addUser(@RequestBody UserInfo userEntity)
  {
    userRepositoy.save(userEntity);
    ResultMsg resultMsg = new ResultMsg(ResultStatusCode.OK.getErrcode(), ResultStatusCode.OK.getErrmsg(), userEntity);
    return resultMsg;
  } 

  @Modifying
  @RequestMapping("updateuser")
  public Object updateUser(@RequestBody UserInfo userEntity)
  {
    UserInfo user = userRepositoy.findUserInfoById(userEntity.getId());
    if (user != null)
    {
      user.setName(userEntity.getName());
      userRepositoy.save(user);
    }
    ResultMsg resultMsg = new ResultMsg(ResultStatusCode.OK.getErrcode(), ResultStatusCode.OK.getErrmsg(), null);
    return resultMsg;
  } 

  @Modifying
  @RequestMapping("deleteuser")
  public Object deleteUser(int id)
  {
    userRepositoy.delete(id);
    ResultMsg resultMsg = new ResultMsg(ResultStatusCode.OK.getErrcode(), ResultStatusCode.OK.getErrmsg(), null);
    return resultMsg;
  }
} 

6、封装返回的结果

添加ResultMsg.java

package com.xiaofangtech.sunt.utils; 

public class ResultMsg {
  private int errcode;
  private String errmsg;
  private Object p2pdata; 

  public ResultMsg(int ErrCode, String ErrMsg, Object P2pData)
  {
    this.errcode = ErrCode;
    this.errmsg = ErrMsg;
    this.p2pdata = P2pData;
  }
  public int getErrcode() {
    return errcode;
  }
  public void setErrcode(int errcode) {
    this.errcode = errcode;
  }
  public String getErrmsg() {
    return errmsg;
  }
  public void setErrmsg(String errmsg) {
    this.errmsg = errmsg;
  }
  public Object getP2pdata() {
    return p2pdata;
  }
  public void setP2pdata(Object p2pdata) {
    this.p2pdata = p2pdata;
  }
}

添加枚举类ResultStatusCode.java

package com.xiaofangtech.sunt.utils; 

public enum ResultStatusCode {
  OK(0, "OK"),
  SYSTEM_ERR(30001, "System error"); 

  private int errcode;
  private String errmsg;
  public int getErrcode() {
    return errcode;
  } 

  public void setErrcode(int errcode) {
    this.errcode = errcode;
  } 

  public String getErrmsg() {
    return errmsg;
  } 

  public void setErrmsg(String errmsg) {
    this.errmsg = errmsg;
  }
  private ResultStatusCode(int Errode, String ErrMsg)
  {
    this.errcode = Errode;
    this.errmsg = ErrMsg;
  }
} 

7、工程整体结构

8、运行测试，本文中测试使用的是user表，其中包含一些密码等信息未做处理，这个读者自行进行JsonIgnore处理

提供以下5个接口

http://localhost:8080/user/adduser

http://localhost:8080/user/updateuser

http://localhost:8080/user/getuser?id=13

http://localhost:8080/user/getusers?role=Manager

http://localhost:8080/user/deleteuser?id=13

测试运行结果

adduser接口

updateuser接口

getuser接口

9、调用以上接口时执行数据库操作时，会在内部转化为以下SQL语句

Hibernate: insert into t_user (name, password, role, salt) values (?, ?, ?, ?)

Hibernate: select userinfo0_.id as id1_0_, userinfo0_.name as name2_0_, userinfo0_.password as password3_0_, userinfo0_.role as role4_0_, userinfo0_.salt as salt5_0_ from t_user userinfo0_ where userinfo0_.id=?
Hibernate: update t_user set name=?, password=?, role=?, salt=? where id=?

Hibernate: select userinfo0_.id as id1_0_, userinfo0_.name as name2_0_, userinfo0_.password as password3_0_, userinfo0_.role as role4_0_, userinfo0_.salt as salt5_0_ from t_user userinfo0_ where userinfo0_.id=?

Hibernate: select userinfo0_.id as id1_0_, userinfo0_.name as name2_0_, userinfo0_.password as password3_0_, userinfo0_.role as role4_0_, userinfo0_.salt as salt5_0_ from t_user userinfo0_ where userinfo0_.role=?

Hibernate: select userinfo0_.id as id1_0_0_, userinfo0_.name as name2_0_0_, userinfo0_.password as password3_0_0_, userinfo0_.role as role4_0_0_, userinfo0_.salt as salt5_0_0_ from t_user userinfo0_ where userinfo0_.id=?
Hibernate: delete from t_user where id=?

10、数据库操作

JPA模块支持将查询字符串定义在方法名称中

如上例中

根据id值查询UserInfo实例

UserInfo findUserInfoById(int id);

根据role查询UserInfo实例

List<UserInfo> findUserInfoByRole(String role);

也可以直接使用原生的数据库语句

如下使用@Query注解

@Query(value = "select * from t_user limit ?1", nativeQuery =true)
List<UserInfo> findAllUsersByCount(int count);

11、在方法名中添加查询字符串参考

本文源码下载：http://xiazai.jb51.net/201707/yuanma/SpringRest_jb51.rar

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