SpringCloud（第 041 篇）链接Mysql数据库,通过JdbcTemplate编写数据库访问

一、大致介绍

1、前面章节提到了JPA操作访问数据库，本章节我们讲解一下如何用JdbcTemplate操作访问数据库； 2、使用JdbcTemplate是一个相对更底层的操作，可以直接编写sql语句操作数据，更具灵活性； 3、另外配置文件中的mysql数据库配置，那么就得大家自己用自己的了哈； 

二、实现步骤

2.1 添加 maven 引用包

<?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>  	<artifactId>springms-provider-user-mysql-jdbctemplate</artifactId>     <version>1.0-SNAPSHOT</version>     <packaging>jar</packaging> 	     <parent>         <groupId>com.springms.cloud</groupId>         <artifactId>springms-spring-cloud</artifactId>         <version>1.0-SNAPSHOT</version>     </parent> 	 	<dependencies>         <!-- 访问数据库模块 -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-data-jpa</artifactId>         </dependency>          <!-- web模块 -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>          <!-- MYSQL -->         <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>         </dependency>     </dependencies>  </project> 

2.2 添加应用配置文件（springms-provider-user-mysql-jdbctemplate\src\main\resources\application.yml）

server:   port: 8315 spring:   application:     name: springms-provider-user-mysql-jdbctemplate  #全部小写   ##################################################################################################### # mysql 属性配置   datasource:     driver-class-name: com.mysql.jdbc.Driver     url: jdbc:mysql://ip:3306/hmilyylimh     username: username     password: password   jpa:     hibernate:       #ddl-auto: create #ddl-auto:设为create表示每次都重新建表       ddl-auto: update #ddl-auto:设为update表示每次都不会重新建表     show-sql: true #####################################################################################################        ##################################################################################################### # 打印日志 logging:   level:     root: INFO     org.hibernate: INFO     org.hibernate.type.descriptor.sql.BasicBinder: TRACE     org.hibernate.type.descriptor.sql.BasicExtractor: TRACE     com.springms: DEBUG #####################################################################################################  

2.3 添加实体用户类User（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/entity/User.java）

package com.springms.cloud.entity;  public class User {    private Long id;    private String username;    private String name;    private Integer age;    private String balance;    public Long getId() {     return this.id;   }    public void setId(Long id) {     this.id = id;   }    public String getUsername() {     return this.username;   }    public void setUsername(String username) {     this.username = username;   }    public String getName() {     return this.name;   }    public void setName(String name) {     this.name = name;   }    public Integer getAge() {     return this.age;   }    public void setAge(Integer age) {     this.age = age;   }    public String getBalance() {     return this.balance;   }    public void setBalance(String balance) {     this.balance = balance;   }    @Override   public String toString() {     return "User{" +             "id=" + id +             ", username='" + username + '\'' +             ", name='" + name + '\'' +             ", age=" + age +             ", balance='" + balance + '\'' +             '}';   } } 

2.4 添加实体账户类Account（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/entity/Account.java）

package com.springms.cloud.entity;  public class Account {     private int id ;     private String name ;     private double money;      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 double getMoney() {         return money;     }      public void setMoney(double money) {         this.money = money;     }      @Override     public String toString() {         return "Account{" +                 "id=" + id +                 ", name='" + name + '\'' +                 ", money=" + money +                 '}';     } }   

2.5 添加用户DAO接口（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/dao/IUserDao.java）

package com.springms.cloud.dao;  import com.springms.cloud.entity.User;  import java.util.List;  /**  * 简单用户链接Mysql数据库微服务（通过@Repository注解标注该类为持久化操作对象）。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ public interface IUserDao {      User findUserById(Long id);      List<User> findAllUsers();      int insertUser(User user); } 

2.6 添加账号DAO接口（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/dao/IAccountDao.java）

package com.springms.cloud.dao;  import com.springms.cloud.entity.Account; import java.util.List;   public interface IAccountDao {      int add(Account account);      int update(Account account);      int delete(int id);      Account findAccountById(int id);      List<Account> findAccountList(); }  

2.7 添加用户DAO接口实现类（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/dao/impl/UserDaoImpl.java）

package com.springms.cloud.dao.impl;  import com.springms.cloud.dao.IUserDao; import com.springms.cloud.entity.User; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.BeanPropertyRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.RowMapper; import org.springframework.stereotype.Repository;  import java.util.List;  /**  * 简单用户链接Mysql数据库微服务（通过@Repository注解标注该类为持久化操作对象）。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ @Repository public class UserDaoImpl implements IUserDao {      /**      * 通过@Resource注解引入JdbcTemplate对象。      */     @Autowired     private JdbcTemplate jdbcTemplate;      //@Transactional(readOnly = true)     @Override     public User findUserById(Long id){         // 1. 定义一个sql语句         String querySQL = "select * from user where id = ?";          // 2. 定义一个RowMapper         RowMapper<User> rowMapper = new BeanPropertyRowMapper<User>(User.class);          // 3. 执行查询方法          //List<User> list = jdbcTemplate.query("select * from account where id = ?", new Object[]{id}, new BeanPropertyRowMapper(User.class));          User user = jdbcTemplate.queryForObject(querySQL, new Object[]{id}, rowMapper);          return user;     }      //@Transactional(readOnly = true)     @Override     public List<User> findAllUsers(){         // 1. 定义一个sql语句         String querySQL = "select * from user";          // 2. 定义一个RowMapper         RowMapper<User> rowMapper = new BeanPropertyRowMapper<User>(User.class);          // 3. 执行查询方法         List<User> users = jdbcTemplate.query(querySQL, new Object[]{}, rowMapper);          return users;     }      @Override     public int insertUser(User user) {         // 1. 定义一个sql语句         String execSQL = "INSERT into user (username, name, age, balance) values (?, ?, ?, ?)";          // 2. 执行查询方法         return jdbcTemplate.update(execSQL,                 new Object[]{user.getUsername(), user.getName(), user.getAge(), user.getBalance()});     } } 

2.8 添加账号DAO接口实现类（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/dao/impl/AccountDaoImpl.java）

package com.springms.cloud.dao.impl;  import com.springms.cloud.dao.IAccountDao; import com.springms.cloud.entity.Account; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.jdbc.core.BeanPropertyRowMapper; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.stereotype.Repository;  import java.util.List;   @Repository public class AccountDaoImpl implements IAccountDao {      @Autowired     private JdbcTemplate jdbcTemplate;      @Override     public int add(Account account) {         return jdbcTemplate.update("insert into account(name, money) values(?, ?)",               account.getName(),account.getMoney());      }      @Override     public int update(Account account) {         return jdbcTemplate.update("UPDATE  account SET NAME=? ,money=? WHERE id=?",                 account.getName(),account.getMoney(),account.getId());     }      @Override     public int delete(int id) {         return jdbcTemplate.update("DELETE from TABLE account where id=?",id);     }      @Override     public Account findAccountById(int id) {         List<Account> list = jdbcTemplate.query("select * from account where id = ?", new Object[]{id}, new BeanPropertyRowMapper(Account.class));         if(list!=null && list.size()>0){             Account account = list.get(0);             return account;         }else{             return null;         }     }      @Override     public List<Account> findAccountList() {         List<Account> list = jdbcTemplate.query("select * from account", new Object[]{}, new BeanPropertyRowMapper(Account.class));         if(list!=null && list.size()>0){             return list;         }else{             return null;         }     } } 

2.9 添加用户Service接口（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/service/IUserService.java）

package com.springms.cloud.service;  import com.springms.cloud.entity.User;  import java.util.List;  /**  * 简单用户链接Mysql数据库微服务（通过@Service注解标注该类为持久化操作对象）。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ public interface IUserService {      User findUserById(Long id);      List<User> findAllUsers();      int insertUser(User user); }  

2.10 添加账号Service接口（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/service/IAccountService.java）

package com.springms.cloud.service;  import com.springms.cloud.entity.Account;  import java.util.List;   public interface IAccountService {       int add(Account account);      int update(Account account);      int delete(int id);      Account findAccountById(int id);      List<Account> findAccountList();  }  

2.11 添加用户Service接口实现类（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/service/impl/UserServiceImpl.java）

package com.springms.cloud.service.impl;  import com.springms.cloud.dao.IUserDao; import com.springms.cloud.entity.User; import com.springms.cloud.service.IUserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  import java.util.List;  /**  * 简单用户链接Mysql数据库微服务（通过@Service注解标注该类为持久化操作对象）。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ @Service public class UserServiceImpl implements IUserService {      @Autowired     private IUserDao userDao;      @Override     public User findUserById(Long id){         return userDao.findUserById(id);     }      @Override     public List<User> findAllUsers(){         return userDao.findAllUsers();     }      @Override     public int insertUser(User user) {         return userDao.insertUser(user);     } } 

2.12 添加账号Service接口实现类（springms-provider-user-mysql-jdbctemplate/src/main/java/com/springms/cloud/service/impl/AccountServiceImpl.java）

package com.springms.cloud.service.impl;  import com.springms.cloud.dao.IAccountDao; import com.springms.cloud.entity.Account; import com.springms.cloud.service.IAccountService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  import java.util.List;   @Service public class AccountServiceImpl implements IAccountService {      @Autowired     IAccountDao accountDAO;      @Override     public int add(Account account) {         return accountDAO.add(account);     }      @Override     public int update(Account account) {         return accountDAO.update(account);     }      @Override     public int delete(int id) {         return accountDAO.delete(id);     }      @Override     public Account findAccountById(int id) {         return accountDAO.findAccountById(id);     }      @Override     public List<Account> findAccountList() {         return accountDAO.findAccountList();     } } 

2.13 添加用户Web访问层Controller（springms-provider-user-mysql-crudrepository/src/main/java/com/springms/cloud/controller/ProviderUserMysqlCrudRepoController.java）

package com.springms.cloud.controller;  import com.springms.cloud.service.IUserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*;  import com.springms.cloud.entity.User; import java.util.List;  /**  * 用户微服务Controller。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ @RestController public class ProviderUserMysqlJdbcController {      @Autowired     private IUserService userService;      @GetMapping("/simplejdbc/{id}")     public User findUserById(@PathVariable Long id) {         return this.userService.findUserById(id);     }      @GetMapping("/simplejdbc/list")     public List<User> findAllUsers() {         return this.userService.findAllUsers();     }      /**      * 添加一个student,使用postMapping接收post请求      *      * http://localhost:8315/simple/addUser?username=user11&age=11&balance=11      *      * @return      */     @PostMapping("/simplejdbc/addUser")     public User insertUser(@RequestParam(value = "username", required=false) String username, @RequestParam(value = "age", required=false) Integer age, @RequestParam(value = "balance", required=false) String balance){         User user=new User();          user.setUsername(username);         user.setName(username);         user.setAge(age);         user.setBalance(balance);          int result = userService.insertUser(user);         if(result > 0){             return user;         }          user.setId(0L);         user.setName(null);         user.setUsername(null);         user.setBalance(null);         return user;     } } 

2.14 添加账号Web访问层Controller（springms-provider-user-mysql-crudrepository/src/main/java/com/springms/cloud/controller/ProviderUserMysqlCrudRepoController.java）

package com.springms.cloud.controller;  import com.springms.cloud.entity.Account; import com.springms.cloud.service.IAccountService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*;  import java.util.List;   @RestController @RequestMapping("/account") public class AccountController {      @Autowired     IAccountService accountService;      @RequestMapping(value = "/list",method = RequestMethod.GET)     public  List<Account> getAccounts(){        return accountService.findAccountList();     }      @RequestMapping(value = "/{id}",method = RequestMethod.GET)     public  Account getAccountById(@PathVariable("id") int id){         return accountService.findAccountById(id);     }      @RequestMapping(value = "/{id}",method = RequestMethod.PUT)     public  String updateAccount(@PathVariable("id")int id , @RequestParam(value = "name",required = true)String name,     @RequestParam(value = "money" ,required = true)double money){         Account account=new Account();         account.setMoney(money);         account.setName(name);         account.setId(id);         int t=accountService.update(account);         if(t==1){             return account.toString();         }else {             return "fail";         }     }      @RequestMapping(value = "",method = RequestMethod.POST)     public  String postAccount( @RequestParam(value = "name")String name,                                  @RequestParam(value = "money" )double money){         Account account=new Account();         account.setMoney(money);         account.setName(name);         int t= accountService.add(account);         if(t==1){             return account.toString();         }else {             return "fail";         }     } } 

2.15 添加微服务启动类（springms-provider-user-mysql-crudrepository/src/main/java/com/springms/cloud/MsProviderUserMysqlCrudRepoApplication.java）

package com.springms.cloud;  import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;  /**  * 链接Mysql数据库,通过JdbcTemplate编写数据库访问。  *  * @author hmilyylimh  *  * @version 0.0.1  *  * @date 17/10/18  *  */ @SpringBootApplication public class MsProviderUserMysqlJdbcApplication {  	public static void main(String[] args) { 		SpringApplication.run(MsProviderUserMysqlJdbcApplication.class, args); 		System.out.println("【【【【【【 链接MysqlJdbc数据库微服务 】】】】】】已启动."); 	} }  

三、测试

/****************************************************************************************  一、简单用户链接Mysql数据库微服务（通过JdbcTemplate编写数据访问）：   1、启动 springms-provider-user-mysql-jdbctemplate 模块服务，启动1个端口；  2、在浏览器输入地址 http://localhost:8315/simplejdbc/6 可以看到用户ID=10的信息成功的被打印出来；   3、使用 IDEA 自带工具 Test Restful WebService 发送 HTTP POST 请求,并添加 username、age、balance三个参数，然后执行请求，并去 mysql 数据库查看数据是否存在，正常情况下 mysql 数据库刚刚插入的数据成功了:  4、使用 REST Client 执行 "/simplejdbc/list" 接口，也正常将 mysql 数据库中所有的用户信息打印出来了；   5、然后再操作 http://localhost:8315/account/ 该链接的接口操作，也是可以正常操作访问的；  ****************************************************************************************/  

四、下载地址

https://git.oschina.net/ylimhhmily/SpringCloudTutorial.git

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