Spring Boot 之 Accessing Relational Data using JDBC with Spring

Accessing Relational Data using JDBC with Spring

使用Spring jdbc 访问关系型数据

环境：

JDK1.8 or later

Gradle 2.3+ or Maven 3.0+

下载官方demo:

git clone https://github.com/spring-guides/gs-relational-data-access.git

进入目录

cd into 

gs-relational-data-access/initial

maven pom.xml 

<?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>org.springframework</groupId>
<artifactId>gs-relational-data-access</artifactId>
<version>0.1.0</version>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.1.RELEASE</version>
</parent>

<properties>
<java.version>1.8</java.version>
</properties>

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

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

domain model 

package hello;

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
}

存储、获取数据

package hello;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.jdbc.core.JdbcTemplate;

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

@SpringBootApplication
public class Application implements CommandLineRunner {

private static final Logger log = LoggerFactory.getLogger(Application.class);

public static void main(String args[]) {
SpringApplication.run(Application.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()));
}
}

使用了java8 新特性 函数式编程。spring 提供了jdbcTemplate模版来访问关系型数据库。它使你能专注于业务逻辑，而不用关心

链接管理，异常处理

H2 是内存关系型数据库 会自动创建一个连接。因为我们使用spring-jdbc,springboot 会自动创建JdbcTemplate,

接下来运行main()方法

: Creating tables
2015-06-19 10:58:31.219  INFO 67731 --- [           main] hello.Application                        : Inserting customer record for John Woo
2015-06-19 10:58:31.220  INFO 67731 --- [           main] hello.Application                        : Inserting customer record for Jeff Dean
2015-06-19 10:58:31.220  INFO 67731 --- [           main] hello.Application                        : Inserting customer record for Josh Bloch
2015-06-19 10:58:31.220  INFO 67731 --- [           main] hello.Application                        : Inserting customer record for Josh Long
2015-06-19 10:58:31.230  INFO 67731 --- [           main] hello.Application                        : Querying for customer records where first_name = 'Josh':
2015-06-19 10:58:31.242  INFO 67731 --- [           main] hello.Application                        : Customer[id=3, firstName='Josh', lastName='Bloch']
2015-06-19 10:58:31.242  INFO 67731 --- [           main] hello.Application                        : Customer[id=4, firstName='Josh', lastName='Long']
2015-06-19 10:58:31.244  INFO 67731 --- [           main] hello.Application                        : Started Application in 1.693 seconds (JVM running for 2.054)

原文：https://spring.io/guides/gs/relational-data-access/