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

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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

    
        
     
      4.0.0
         
     
      springms-provider-user-mysql-jdbctemplate
         
     
      1.0-SNAPSHOT
         
     
      jar
             
             
      
       com.springms.cloud
              
      
       springms-spring-cloud
              
      
       1.0-SNAPSHOT
          
             
             
              
                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-data-jpa
               
              
              
                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-web
               
              
              
                  
       
        mysql
                   
       
        mysql-connector-java
               
          
     
    

2.2 添加应用配置文件（springms-provider-user-mysql-jdbctemplatesrcmainresourcesapplication.yml）

server:  port: 8315spring:  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
    
      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
    
      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 * */@Repositorypublic 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
    
      rowMapper = new BeanPropertyRowMapper
     
      (User.class);        // 3. 执行查询方法        //List
      
        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
       
         findAllUsers(){        // 1. 定义一个sql语句        String querySQL = "select * from user";        // 2. 定义一个RowMapper        RowMapper
        
          rowMapper = new BeanPropertyRowMapper
         
          (User.class); // 3. 执行查询方法 List
          
            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;@Repositorypublic 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
    
      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
     
       findAccountList() {        List
      
        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
    
      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
    
      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 * */@Servicepublic class UserServiceImpl implements IUserService {    @Autowired    private IUserDao userDao;    @Override    public User findUserById(Long id){        return userDao.findUserById(id);    }    @Override    public List
    
      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;@Servicepublic 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
    
      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 * */@RestControllerpublic 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
    
      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
    
      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 * */@SpringBootApplicationpublic 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； ****************************************************************************************/

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