25 -SpringBoot學習（3）- 數據庫訪問(1)

1 springboot 使用 jdbc

1. 添加依賴

<!-- JDBC -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-jdbc</artifactId>
		</dependency>
		<!-- 數據庫驅動 -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

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2. 配置文件
   

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3. Service

package com.tzb.service;

public interface IUserService {
    public void register(String username,String password);
}

package com.tzb.service.impl;

import com.tzb.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements IUserService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public void register(String username, String password) {
        String sql = "insert t_user (username,password) values(?,?)";
        jdbcTemplate.update(sql, username, password);
    }
}

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4. 控制器

package com.tzb.web.controller;

import com.tzb.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping("user")
public class UserController {

    @Autowired
    private IUserService service;

    @RequestMapping("register")
    @ResponseBody // 返回 json
    public String register(String username,String password){
        service.register(username,password);
        return "success";
    }
}

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5. 運行

package com.tzb.web.controller.main;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;

@EnableAutoConfiguration
@ComponentScan(basePackages = {"com.tzb.service", "com.tzb.web"})
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

2 整合 mybatis

使用 maven jar項目

1. 依賴

  <!--springboot-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <!-- 單元測試 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- mybaties -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- mysql驅動 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

    </dependencies>

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2. 數據庫配置文件
   

#數據庫配置
spring.datasource.url=jdbc:mysql://localhost:3306/springboot_test?characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

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3. mapper 接口
   

package com.tzb.springboot.mapper;

import com.tzb.springboot.model.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;

public interface UserMapper {

    @Insert("INSERT t_user (username,password) values (#{username},#{password})")
    public int save(@Param("username") String username,@Param("password") String password);

    @Insert("select * from t_user where username = #{username}")
    public User findByUsername(@Param("username") String username);
}

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4. service

@Service
public class UserServiceImpl implements IUserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public void register(String username, String password) {
        userMapper.save(username, password);
    }
}

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5. 控制器

@RestController
@RequestMapping("user")
public class UserController {

    @Autowired
    private IUserService userService;

    @RequestMapping("register")
    @ResponseBody // 返回的數據轉爲 json
    public String register(String username, String password) {
        userService.register(username, password);
        return "SUCCESS";
    }
}

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6. App.java

@EnableAutoConfiguration
@ComponentScan(basePackages = "com.tzb.springboot")
@MapperScan(basePackages = "com.tzb.springboot.mapper")
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

2.1 mapper 使用 xml 配置

• Mapper 類

public interface UserMapper {

    public int save(String username, String password);

    public User findByUsername(String username);

  /*  @Insert("INSERT t_user (username,password) values (#{username},#{password})")
    public int save(@Param("username") String username,@Param("password") String password);

    @Insert("select * from t_user where username = #{username}")
    public User findByUsername(@Param("username") String username);*/
}

• UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.tzb.springboot.mapper.UserMapper" >

    <insert id="save">
        insert into t_user (username,password) VALUES(#{0},#{1})
    </insert>
    <select id="findByUsername" resultType="com.tzb.springboot.model.User" parameterType="string">
        select * from t_user where username = #{username,jdbcType=VARCHAR}
    </select>
</mapper>

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注意這裏需要在pom中添加下面代碼

<build>
  <resources>
    <resource>
      <directory>src/main/java</directory>
      <includes>
        <include>**/*.xml</include>
      </includes>
    </resource>
  </resources>
</build>

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3 spring中使用的事務