Spring Boot如何使用JDBC获取相关的数据详解

<dependencies> <dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency>  <groupId>com.h2database</groupId>  <artifactId>h2</artifactId> </dependency> </dependencies>

package com.example.kane.Model;public class Customer { private long id; private String firstName, lastName; public Customer(long id, String firstName, String lastName) { this.id = id; this.firstName = firstName; this.lastName = lastName; } @Override public String toString() { return String.format(  "Customer[id=%d, firstName='%s', lastName='%s']",  id, firstName, lastName); } // getters & setters omitted for brevity}

package com.example.kane;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.CommandLineRunner;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.web.client.RestTemplateBuilder;import org.springframework.context.annotation.Bean;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.scheduling.annotation.EnableScheduling;import java.util.Arrays;import java.util.List;import java.util.stream.Collectors;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.client.RestTemplate;import com.example.kane.Model.Customer;@SpringBootApplication//@EnableSchedulingpublic class RestfulWebService1Application implements CommandLineRunner{  private static final Logger log = LoggerFactory.getLogger(RestfulWebService1Application.class); public static void main(String args[]) { SpringApplication.run(RestfulWebService1Application.class, args); } @Autowired JdbcTemplate jdbcTemplate; @Override public void run(String... strings) throws Exception { log.info("Creating tables"); jdbcTemplate.execute("DROP TABLE customers IF EXISTS"); jdbcTemplate.execute("CREATE TABLE customers(" +  "id SERIAL, first_name VARCHAR(255), last_name VARCHAR(255))"); // Split up the array of whole names into an array of first/last names List<Object[]> splitUpNames = Arrays.asList("John Woo", "Jeff Dean", "Josh Bloch", "Josh Long").stream()  .map(name -> name.split(" "))  .collect(Collectors.toList()); // Use a Java 8 stream to print out each tuple of the list splitUpNames.forEach(name -> log.info(String.format("Inserting customer record for %s %s", name[0], name[1]))); // Uses JdbcTemplate's batchUpdate operation to bulk load data jdbcTemplate.batchUpdate("INSERT INTO customers(first_name, last_name) VALUES (?,?)", splitUpNames); log.info("Querying for customer records where first_name = 'Josh':"); jdbcTemplate.query(  "SELECT id, first_name, last_name FROM customers WHERE first_name = ?", new Object[] { "Josh" },  (rs, rowNum) -> new Customer(rs.getLong("id"), rs.getString("first_name"), rs.getString("last_name")) ).forEach(customer -> log.info(customer.toString())); }}

package com.example.kane.Model;import org.springframework.boot.CommandLineRunner;import org.springframework.core.annotation.Order;import org.springframework.stereotype.Component;@Component@Order(value=1) //因为可能有许多事情要做，Order 可以根据大小，判读执行的顺序public class run_after_application implements CommandLineRunner{ @Override public void run(String... args) throws Exception { // TODO Auto-generated method stub System.out.println("-----------------------"); } }

//为Bean创建一个JdbcTemplate以供使用//再没配置DataSource的情况下 springboot提供了 一些嵌入式的数据库支持，上面的例子使用的就是H2数据库，是一个内存的数据库

//构造的时候传入一个 DataSource，来获取链接//JdbcTemplate Spring boot默认链接的是H2 database，

package com.example.kane.config;import org.apache.commons.dbcp.BasicDataSource;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import javax.sql.DataSource;@Configurationpublic class db_config { //这个类是一个Config类 @Value("${db.driver}") private String DRIVER; @Value("${db.password}") private String PASSWORD; @Value("${db.url}") private String URL; @Value("${db.username}") private String USERNAME; @Bean public DataSource dataSource1() {  BasicDataSource dataSource = new BasicDataSource();  dataSource.setDriverClassName(DRIVER);  dataSource.setUrl(URL);  dataSource.setUsername(USERNAME);  dataSource.setPassword(PASSWORD);  return dataSource; }}

# Database# mysqljdbc连接驱动db.driver:com.mysql.cj.jdbc.Driverdb.url:jdbc:mysql://localhost:3306/testdb.username:rootdb.password:root

<dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version></dependency><dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope></dependency><!-- 需要用到commons-dbcp连接池，以及连接mysql使用的drver-->

 @Autowired JdbcTemplate jdbcTemplate; //下面是加载了数据库的配置。只需要增加这个 @Autowired db_config db_config;

SELECT * from customers;------------------------1 John Woo2 Jeff Dean3 Josh Bloch4 Josh Long

# databasespring.datasource.url=jdbc:mysql://localhost:3306/testspring.datasource.username=rootspring.datasource.password=spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

spring: datasource: url: jdbc:mysql://localhost:3306/test username: root password: root driver-class-name: com.mysql.cj.jdbc.Driver