spring boot整合mybatis使用c3p0資料來源連線mysql
阿新 • • 發佈:2019-01-07
剛剛接觸springboot,對很多東西都不熟悉,例如,它的註解方式,他的配置方式等;聽說它很牛逼,所以就嘗試著去學習。在基本熟悉springboot的第一個程式之後。想到當時spring整合mybatis時使用了資料來源連線資料庫,所以自己也想嘗試使用c3p0連線資料庫。所以就有了以下的內容:
首先第一步,建立maven專案匯入包:
pom.xml
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId >
<version>1.4.1.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope> test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>1.4.1.RELEASE</version>
</dependency>
<dependency >
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>1.4.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.33</version>
</dependency>
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
應用服務類
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan(value="com.myk.spring.t3")//掃描mapper包
@EnableAutoConfiguration//自動載入應用程式所需的所有Bean,當使用Exclude這個屬性時,是禁止自動配置某個類
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
配置檔案內容(配置資料庫)
datasource:
url: jdbc:mysql://ip:port/databaseName
driver-class: com.mysql.jdbc.Driver
username: ***
password: ***
準備無誤,嘗試啟用應用服務,沒有報錯即可繼續
配置資料來源,嘗試很多方法,自己注入是不可能的,所以,我就想到spring的配置,嘗試按照那樣的方式去配置,所以,
DataSourceConfig.java
import javax.sql.DataSource;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import com.mchange.v2.c3p0.ComboPooledDataSource;
@Configuration
public class DataSourceConfig {
@Bean(name="dataSource")
@Qualifier(value="dataSource")//限定描述符除了能根據名字進行注入,但能進行更細粒度的控制如何選擇候選者
@Primary//用@Primary區分主資料來源
@ConfigurationProperties(prefix="c3p0.primary")//指定配置檔案中,字首為c3p0的屬性值
public DataSource dataSource(){
return DataSourceBuilder.create().type(ComboPooledDataSource.class).build();//建立資料來源
}
/**
*返回sqlSessionFactory
*/
@Bean
public SqlSessionFactoryBean sqlSessionFactoryBean(){
SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();
sqlSessionFactory.setDataSource(dataSource());
return sqlSessionFactory;
}
}
也許會有疑問,為什麼這裡只需要一個sqlSessionFactory,這個具體要去熟悉spring整合mybatis。還有看看底層就明白了
這樣就可以自動裝配了。
資料來源都準備好了,嘗試連線資料庫吧
編輯介面
ExamPleMapper.java
import java.util.List;
public interface ExamPleMapper {
public List<Users> getUsers();
}
編輯Mapper xml檔案
<?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.*.ExamPleMapper">
<select id="getUsers" resultType="com.*.Users">
select * from users
</select>
</mapper>
編輯實體類,因為要將結果反射到bean類中
Users.java
public class Users {
private int userid;
private String username;
@Override
public String toString() {
return "Users [userid=" + userid + ", username=" + username + "]";
}
public int getUserid() {
return userid;
}
public void setUserid(int userid) {
this.userid = userid;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public Users(int userid, String username) {
super();
this.userid = userid;
this.username = username;
}
public Users() {
super();
// TODO Auto-generated constructor stub
}
}
編輯實現
Example2.java
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping(value="/example2")//對映
public class Example2 {
@Autowired
public ExamPleMapper examPleMapper;
@ResponseBody
@RequestMapping(value="/gu")
public List<Users> getUsers(){
return examPleMapper.getUsers();
}
}
輸入地址:http://localhost:8080/example2/gu
頁面顯示結果:
[{“userid”:1,”username”:”as”},{“userid”:2,”username”:”we”},{“userid”:3,”username”:”zx”}]