Spring boot with PostgreSQL

时间:2022-05-03
本文章向大家介绍Spring boot with PostgreSQL,主要内容包括本文节选自《Netkiller Java 手札》 作者 netkiller 他的网站 http://www.netkiller.cn、5.15. Spring boot with PostgreSQL、5.15.2. application.properties、5.15.3. Application、5.15.4. CrudRepository、5.15.5. JdbcTemplate、5.15.6. Controller、5.15.7. Test、基本概念、基础应用、原理机制和需要注意的事项等,并结合实例形式分析了其使用技巧,希望通过本文能帮助到大家理解应用这部分内容。

本文节选自《Netkiller Java 手札》 作者 netkiller 他的网站 http://www.netkiller.cn

5.15. Spring boot with PostgreSQL

5.15.1. pom.xml

			<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>9.4.1212</version>
</dependency>			

5.15.2. application.properties

 spring.datasource.platform=postgres
spring.database.driverClassName=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://localhost:5432/your-database
spring.datasource.username=postgres
spring.datasource.password=postgres

spring.jpa.database=POSTGRESQL
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.generate-ddl=true			

5.15.3. Application

			package cn.netkiller;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableAutoConfiguration
@ComponentScan
@EnableMongoRepositories
@EnableJpaRepositories
@EnableScheduling
public class Application {

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

5.15.4. CrudRepository

Model Class

			package cn.netkiller.model;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "customer")
public class Customer implements Serializable {

	private static final long serialVersionUID = -3009077722242246666L;
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private long id;

	@Column(name = "firstname")
	private String firstName;

	@Column(name = "lastname")
	private String lastName;

	protected Customer() {
	}

	public Customer(String firstName, String lastName) {
		this.firstName = firstName;
		this.lastName = lastName;
	}

	@Override
	public String toString() {
		return String.format("Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
	}
}			

CrudRepository

			package cn.netkiller.repository;

import java.util.List;

import org.springframework.data.repository.CrudRepository;

import cn.netkiller.model.Customer;

public interface CustomerRepository extends CrudRepository<Customer, Long>{
	List<Customer> findByFirstName(String firstName);
    List<Customer> findByLastName(String lastName);
}			

5.15.5. JdbcTemplate

	@Autowired
	private JdbcTemplate jdbcTemplate;

	@RequestMapping(value = "/jdbc")
	public @ResponseBody String dailyStats(@RequestParam Integer id) {
		String query = "SELECT id, firstname, lastname from customer where id = " + id;

		return jdbcTemplate.queryForObject(query, (resultSet, i) -> {
			System.out.println(resultSet.getLong(1)+","+ resultSet.getString(2)+","+ resultSet.getString(3));
			return (resultSet.getLong(1)+","+ resultSet.getString(2)+","+ resultSet.getString(3));
		});
	}			

5.15.6. Controller

			package cn.netkiller.web;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import cn.netkiller.model.Customer;
import cn.netkiller.repository.CustomerRepository;

@Controller
@RequestMapping("/test/pgsql")
public class TestPostgreSQLController {

	@Autowired
	private CustomerRepository customerRepository;

	@RequestMapping("/save")
	public @ResponseBody String process() {
		customerRepository.save(new Customer("Neo", "Chan"));
		customerRepository.save(new Customer("Luke", "Liu"));
		customerRepository.save(new Customer("Ran", "Guo"));
		customerRepository.save(new Customer("Joey", "Chen"));
		customerRepository.save(new Customer("Larry", "Huang"));
		return "Done";
	}

	@RequestMapping("/findall")
	public @ResponseBody String findAll() {
		String result = "<html>";

		for (Customer cust : customerRepository.findAll()) {
			result += "<div>" + cust.toString() + "</div>";
		}

		return result + "</html>";
	}

	@RequestMapping("/findbyid")
	public @ResponseBody String findById(@RequestParam("id") long id) {
		String result = "";
		result = customerRepository.findOne(id).toString();
		return result;
	}

	@RequestMapping("/findbylastname")
	public @ResponseBody String fetchDataByLastName(@RequestParam("lastname") String lastName) {
		String result = "<html>";

		for (Customer cust : customerRepository.findByLastName(lastName)) {
			result += "<div>" + cust.toString() + "</div>";
		}

		return result + "</html>";
	}

	@Autowired
	private JdbcTemplate jdbcTemplate;

	@RequestMapping(value = "/jdbc")
	public @ResponseBody String dailyStats(@RequestParam Integer id) {
		String query = "SELECT id, firstname, lastname from customer where id = " + id;

		return jdbcTemplate.queryForObject(query, (resultSet, i) -> {
			System.out.println(resultSet.getLong(1)+","+ resultSet.getString(2)+","+ resultSet.getString(3));
			return (resultSet.getLong(1)+","+ resultSet.getString(2)+","+ resultSet.getString(3));
		});
	}
}			

5.15.7. Test

curl http://127.0.0.1:7000/test/pgsql/save
curl http://127.0.0.1:7000/test/pgsql/findall
curl http://127.0.0.1:7000/test/pgsql/findbyid?id=1
curl http://127.0.0.1:7000/test/pgsql/jdbc?id=1