spring boot与jdbcTemplate的整合案例2

Posted 2020-10-18 javaobject

简单入门了spring boot后，接下来写写跟数据库打交道的案例。博文采用spring的jdbcTemplate工具类与数据库打交道。

     下面是搭建的springbootJDBC的项目的总体架构图：

 

<?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>  
  
    <groupId>com.example</groupId>  
    <artifactId>demo</artifactId>  
    <version>0.0.1-SNAPSHOT</version>  
    <packaging>jar</packaging>  
  
    <name>demo</name>  
    <description>Demo project for Spring Boot</description>  
  
    <parent>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-parent</artifactId>  
        <version>1.5.2.RELEASE</version>  
        <relativePath/> <!-- lookup parent from repository -->  
    </parent>  
  
    <properties>  
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>  
        <java.version>1.8</java.version>  
    </properties>  
  
    <dependencies>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-web</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-jdbc</artifactId>  
        </dependency>  
  
        <dependency>  
            <groupId>mysql</groupId>  
            <artifactId>mysql-connector-java</artifactId>  
            <scope>runtime</scope>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-test</artifactId>  
            <scope>test</scope>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-test</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>com.google.guava</groupId>  
            <artifactId>guava</artifactId>  
            <version>18.0</version>  
        </dependency>  
    </dependencies>  
  
    <!--spring boot maven插件-->  
    <build>  
        <plugins>  
            <plugin>  
                <groupId>org.springframework.boot</groupId>  
                <artifactId>spring-boot-maven-plugin</artifactId>  
            </plugin>  
        </plugins>  
    </build>  
  
</project>  

  接下来，贴出application.properties，设置tomcat端口号，数据库链接相关信息：

 可以参照上一篇博文，参考参考如何建立一个spring boot项目，至于在选择依赖的配置时候，可以参考我下面贴出的pom.xml：

###### 设置tomcat访问端口号 ######  
server.port=8088  
  
###### 设置数据源 ######  
spring.datasource.url=jdbc:mysql://localhost:3306/db_springboot?autoReconnect=true&useUnicode=true&characterEncoding=utf-8  
spring.datasource.username=root  
spring.datasource.password=123456  
spring.datasource.driver-class-name=com.mysql.jdbc.Driver  
#spring.datasource.driverClassName = com.mysql.jdbc.Driver  

 建立数据库tb_springboot，然后执行下面的sql脚本，生成users表：

/*  
Navicat MySQL Data Transfer  
  
Source Server         : localhost  
Source Server Version : 50625  
Source Host           : localhost:3306  
Source Database       : db_springboot  
  
Target Server Type    : MYSQL  
Target Server Version : 50625  
File Encoding         : 65001  
  
Date: 2017-03-31 15:01:08  
*/  
  
SET FOREIGN_KEY_CHECKS=0;  
  
-- ----------------------------  
-- Table structure for users  
-- ----------------------------  
DROP TABLE IF EXISTS `users`;  
CREATE TABLE `users` (  
  `id` int(11) NOT NULL AUTO_INCREMENT,  
  `name` varchar(255) DEFAULT NULL,  
  `email` varchar(255) DEFAULT NULL,  
  PRIMARY KEY (`id`)  
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;  
  
-- ----------------------------  
-- Records of users  
-- ----------------------------  
INSERT INTO `users` VALUES (‘1‘, ‘linsen‘, ‘[email protected]‘);  
INSERT INTO `users` VALUES (‘2‘, ‘sam‘, ‘[email protected]‘);  
INSERT INTO `users` VALUES (‘3‘, ‘debug‘, ‘[email protected]‘);  
INSERT INTO `users` VALUES (‘4‘, ‘杰克‘, ‘杰克@sina.com‘);  
INSERT INTO `users` VALUES (‘5‘, ‘张三‘, ‘张三@sina.com‘);  
INSERT INTO `users` VALUES (‘6‘, ‘李四‘, ‘李四@sina.com‘);  
INSERT INTO `users` VALUES (‘7‘, ‘王五‘, ‘王五@sina.com‘);  
INSERT INTO `users` VALUES (‘8‘, ‘王五2‘, ‘王五[email protected]‘);  

   本博文我们对spring boot与jdbcTemplate进行整合，主要当然是实现基本的 增删改查 user实体 操作，首先是开发dao层：

package com.example.repository;  
  
import com.example.entity.User;  
import com.example.exception.UserException;  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.jdbc.core.JdbcTemplate;  
import org.springframework.jdbc.core.PreparedStatementCreator;  
import org.springframework.jdbc.core.PreparedStatementSetter;  
import org.springframework.jdbc.core.RowMapper;  
import org.springframework.jdbc.support.GeneratedKeyHolder;  
import org.springframework.jdbc.support.KeyHolder;  
import org.springframework.stereotype.Repository;  
import org.springframework.transaction.annotation.Transactional;  
  
import java.sql.Connection;  
import java.sql.PreparedStatement;  
import java.sql.ResultSet;  
import java.sql.SQLException;  
import java.util.ArrayList;  
import java.util.List;  
  
/** 
 * Created by steadyjack on 2017/3/22. 
 * 充当dao层UserRepository 
 */  
@Repository  
public class UserRepository {  
  
    @Autowired  
    private JdbcTemplate jdbcTemplate;  
  
    /** 
     * 获取用户列表 
     * @return 
     * @throws Exception 
     */  
    @Transactional(readOnly = true)  
    public List<User> getUserList() throws Exception{  
        List<User> userList=jdbcTemplate.query("select id,name,email from users",new UserRowMapper());  
        System.out.println(userList);  
        return userList;  
    }  
  
    /** 
     * 根据用户id获取用户 
     * @param id 
     * @return 
     * @throws Exception 
     */  
    @Transactional(readOnly = true)  
    public User getUserById(Integer id) throws  Exception{  
        //queryForObject:找不到会报异常  query:找不到则Null  
        //User user=jdbcTemplate.queryForObject("select id,name,email from users where id=?",new Object[]{id},new UserRowMapper());  
        List<User> userList=jdbcTemplate.query("select id,name,email from users where id=?",new Object[]{id},new UserRowMapper());  
        User user=null;  
        if (!userList.isEmpty()){  
            user=userList.get(0);  
        }  
        System.out.println(user);  
        return user;  
    }  
  
    /** 
     * 插入用户数据 
     * @param user 
     * @return 
     * @throws Exception 
     */  
    public int saveUser(final User user) throws  Exception{  
        int resRow=jdbcTemplate.update("INSERT INTO users(id,name,email) VALUES(NULL,?,?)",new Object[]{  
           user.getName(),user.getEmail()  
        });  
        System.out.println("操作结果记录数：  "+resRow);  
        return resRow;  
    }  
  
    /** 
     * 插入用户数据-防止sql注入 
     * @param user 
     * @return 
     * @throws Exception 
     */  
    public int saveUserWithSafe(final User user) throws  Exception{  
        int resRow=jdbcTemplate.update("INSERT INTO users(id,name,email) VALUES(NULL,?,?)", new PreparedStatementSetter() {  
            @Override  
            public void setValues(PreparedStatement ps) throws SQLException {  
                ps.setString(1,user.getName());  
                ps.setString(2,user.getEmail());  
            }  
        });  
        System.out.println("操作结果记录数：  "+resRow);  
        return resRow;  
    }  
  
    /** 
     * 插入用户数据-防止sql注入-可以返回该条记录的主键（注意需要指定主键） 
     * @param user 
     * @return 
     * @throws Exception 
     */  
    @Transactional(rollbackFor=UserException.class)  
    public int saveUserWithKey(final User user) throws  Exception{  
        String sql="INSERT INTO users(id,name,email) VALUES(NULL,?,?)";  
        KeyHolder keyHolder=new GeneratedKeyHolder();  
        int resRow=jdbcTemplate.update(new PreparedStatementCreator() {  
            @Override  
            public PreparedStatement createPreparedStatement(Connection conn) throws SQLException {  
                PreparedStatement ps=conn.prepareStatement(sql,new String[]{"id"}); //指定 id 为主键  
                ps.setString(1,user.getName());  
                ps.setString(2,user.getEmail());  
                return ps;  
            }  
        },keyHolder);  
        System.out.println("操作结果记录数：  "+resRow+" 主键: "+keyHolder.getKey());  
        return Integer.parseInt(keyHolder.getKey().toString());  
    }  
  
    /** 
     * 更新用户信息 
     * @param user 
     * @return 
     */  
    public int updateUser(final User user) throws  Exception{  
        String sql="update users set name=?,email=? where id=?";  
        int resRow=jdbcTemplate.update(sql, new PreparedStatementSetter() {  
            @Override  
            public void setValues(PreparedStatement preparedStatement) throws SQLException {  
                preparedStatement.setString(1,user.getName());  
                preparedStatement.setString(2,user.getEmail());  
                preparedStatement.setInt(3,user.getId());  
            }  
        });  
        System.out.println("操作结果记录数：  "+resRow);  
        return resRow;  
    }  
  
    /** 
     * 删除用户 
     * @param user 
     * @return 
     * @throws Exception 
     */  
    public int deleteUser(final User user) throws  Exception{  
        int resRow=jdbcTemplate.update("DELETE FROM users WHERE id=?", new PreparedStatementSetter() {  
            @Override  
            public void setValues(PreparedStatement ps) throws SQLException {  
                ps.setInt(1,user.getId());  
            }  
        });  
        System.out.println("操作结果记录数：  "+resRow);  
        return resRow;  
    }  
  
    /** 
     * 根据用户名查找用户-用于判断用户是否存在 
     * @param user 
     * @return 
     * @throws Exception 
     */  
    public User getUserByUserName(final User user) throws Exception{  
        String sql="select id,name,email from users where name=?";  
        List<User> queryList=jdbcTemplate.query(sql,new UserRowMapper(),new Object[]{user.getName()});  
        if (queryList!=null && queryList.size()>0){  
            return queryList.get(0);  
        }else{  
            return null;  
        }  
    }  
  
    /** 
     * 获取记录数 
     * @return 
     * @throws Exception 
     */  
    public Integer getCount() throws  Exception{  
        String sql="select count(id) from users";  
        //jdbcTemplate.getMaxRows();  
        Integer total=jdbcTemplate.queryForObject(sql,Integer.class);  
        System.out.println("操作结果记录数：  "+total);  
        return total;  
    }  
  
    //其他的像模糊查询之类的可以自己尝试查查 jdbcTemplate 的使用文档  
  
  
}  
  
/** 
 * 行映射 
 */  
class UserRowMapper implements RowMapper<User>{  
  
    @Override  
    public User mapRow(ResultSet resultSet, int i) throws SQLException {  
        User user=new User();  
        user.setId(resultSet.getInt("id"));  
        user.setName(resultSet.getString("name"));  
        user.setEmail(resultSet.getString("email"));  
        return user;  
    }  
  
}  

代码以及相关的注释我已经写在里面了，个人觉得很清晰了，如果有啥问题，可以下面留言，或者后面提到的技术交流群交流。

    接下来，当然是开发controller层，在这里，我主要开发rest服务接口，结果将以json的格式返回给发起请求的客户端（以postman进行模拟），下面是我的restController：

package com.example.controller;  
  
import com.example.DemoApplication;  
import com.example.entity.User;  
import com.example.repository.UserRepository;  
import com.google.common.base.Strings;  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.boot.test.context.SpringBootTest;  
import org.springframework.web.bind.annotation.PathVariable;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RequestMethod;  
import org.springframework.web.bind.annotation.RestController;  
  
import javax.servlet.http.HttpServletRequest;  
import java.util.List;  
  
/** 
 * Created by steadyjack on 2017/3/22. 
 */  
@SpringBootTest(classes = DemoApplication.class)  
@RestController  
@RequestMapping("/user")  
public class UserController {  
  
    @Autowired  
    private UserRepository userRepository;  
  
    /** 
     * 用户列表 
     * @return 
     */  
    @RequestMapping("/list")  
    public List<User> listUser() {  
        List<User> userList=null;  
        try {  
            userList=userRepository.getUserList();  
        }catch (Exception e){  
            System.out.println("异常信息:  "+e.getMessage());  
        }  
        return userList;  
    }  
  
    /** 
     * 根据id查询User实体 
     * @param id 
     * @return 
     */  
    @RequestMapping("/{id}")  
    public User getUserById(@PathVariable Integer id){  
        User user=null;  
        try {  
            user=userRepository.getUserById(id);  
        }catch (Exception e){  
            user=new User(1,"admin","[email protected]");  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return user;  
    }  
  
    /** 
     * 保存user实体 
     * @param user 
     * @return 
     */  
    @RequestMapping(value = "/save",method = RequestMethod.POST)  
    public int insertUser(User user){  
        int res=1;  
        try {  
            res=userRepository.saveUser(user);  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 保存User实体-PreparedStatementSetter 
     * @param user 
     * @return 
     */  
    @RequestMapping(value = "/saveWithSafe",method = RequestMethod.POST)  
    public int insertUserWithSafe(User user){  
        int res=1;  
        try {  
            res=userRepository.saveUserWithSafe(user);  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 保存user实体-PreparedStatementCreator、KeyHolder-保存实体后返回实体的主键 
     * @param user 
     * @return 
     */  
    @RequestMapping(value = "/saveWithKey",method = RequestMethod.POST)  
    public int insertUserWithKey(User user){  
        int res=1;  
        try {  
            res=userRepository.saveUserWithKey(user);  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 根据id更新user实体 
     * @param id 
     * @param request 
     * @return 
     */  
    @RequestMapping(value = "/update/{id}",method = RequestMethod.POST)  
    public int updateUserWithId(@PathVariable Integer id,HttpServletRequest request){  
        int res=1;  
        try {  
            if (id!=null && !id.equals(0)){  
                String name=request.getParameter("name");  
                String email=request.getParameter("email");  
                User updateUser=new User(id, Strings.isNullOrEmpty(name)?null:name,Strings.isNullOrEmpty(email)?null:email);  
                res=userRepository.updateUser(updateUser);  
            }  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 根据id删除user实体 
     * @param id 
     * @return 
     */  
    @RequestMapping("/delete/{id}")  
    public int deleteUserById(@PathVariable Integer id){  
        int res=1;  
        try {  
            User deleteUser=userRepository.getUserById(id);  
            res=userRepository.deleteUser(deleteUser);  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 根据name查询是否存在某个user实体 
     * @param request 
     * @return 
     */  
    @RequestMapping("/isExistUser")  
    public Boolean isExistUser(HttpServletRequest request){  
        Boolean res=false;  
        try {  
            String name=request.getParameter("name");  
            User queryUser=new User(null,Strings.isNullOrEmpty(name)?null:name,null);  
            User deleteUser=userRepository.getUserByUserName(queryUser);  
            if (deleteUser!=null){  
                res=true;  
            }  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
    /** 
     * 查询user实体的总数 
     * @return 
     */  
    @RequestMapping("/total")  
    public Integer getTotal(){  
        Integer res=0;  
        try {  
            res=userRepository.getCount();  
        }catch (Exception e){  
            System.out.println("异常信息： "+e.getMessage());  
        }  
        return res;  
    }  
  
}  

 至此已经开发完毕了，你可以直接run DemoApplication类，然后在浏览器测试访问，也可以在postman发起访问！下面我才用一键式部署到我的本地tomcat服务器:

   

 

 

    完了之后，（当然啦，你也可以jar -jar将你的spring boot打包为jar项目，然后$ java –jar E:\IDEA_Workspace\springbootJDBC\target\demo-0.0.1-SNAPSHOT.jar 也可以直接跑起来）

    好了，现在默认就是启动了这个sb项目，下面就开始访问测试各个服务（开头都以 127.0.0.1:8088/）

    1，首先是获取用户列表：

   

   2、接着是查询id=3 的user实体：

 

   3、将id=3的实体删除（1：代表操作的记录数-说明已经成功删除）

 

  4、再次查询出来：

 

  5、增加一个user实体：

 

  6、检验一下是否增加该实体成功：

 

    7、更新id=11的实体的相关数据（1：代表更新成功）

 

   8、检验一下是否更新数据成功！

 

    好了，整合完毕！下面提供postman的下载地址（当然了，上面的那些地址其实也可以通过browser进行访问的）