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测试数据mandlinerunner;

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

//@enablescheduling

public 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测试数据mandlinerunner;

import org.springframework.core.annotation.order;

import org.springframework.stereotype测试数据ponent;

@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测试数据mons.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;

@configuration

public 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.driver

db.url:jdbc:mysql: //localhost:3306/test

db.username:root

db.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 woo

2 jeff dean

3 josh bloch

4 josh long

# database

spring.datasource.url=jdbc:mysql: //localhost:3306/test

spring.datasource.username=root

spring.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