前言
前面几章介绍了一些基础,但都是静态的,还不足以构建一个动态的应用。本篇开始就要介绍数据交互了,为了演示效果更加好,博主花了大把时间整合了一个后端模板框架,基于Bootstrap3的ACE模板,并实现了一个基本的增删改查分页功能。让我们一起动手,学技术的同时,顺便把我们的项目完善起来,这样跟着博主学到最后,你就有了一个属于自己的Spring Boot项目啦。
正文
本文介绍在Spring Boot基础下配置数据源和通过JdbcTemplate编写数据访问的示例。
添加依赖
这里需要添加spring-boot-starter-jdbc依赖跟mysql依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
数据源配置
在src/main/resources/application.properties中配置数据源信息。
spring.datasource.url = jdbc:mysql://localhost:3306/spring?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.driver-class-name = com.mysql.jdbc.Driver
自定义数据源
spring-boot-starter-jdbc 默认使用tomcat-jdbc数据源,如果你想使用其他的数据源,比如这里使用了阿里巴巴的数据池管理,你应该额外添加以下依赖:
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.19</version>
</dependency>
修改Application.java
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Autowired
private Environment env;
//destroy-method="close"的作用是当数据库连接不使用的时候,就把该连接重新放到数据池中,方便下次使用调用.
@Bean(destroyMethod = "close")
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setUrl(env.getProperty("spring.datasource.url"));
dataSource.setUsername(env.getProperty("spring.datasource.username"));//用户名
dataSource.setPassword(env.getProperty("spring.datasource.password"));//密码
dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
dataSource.setInitialSize(2);//初始化时建立物理连接的个数
dataSource.setMaxActive(20);//最大连接池数量
dataSource.setMinIdle(0);//最小连接池数量
dataSource.setMaxWait(60000);//获取连接时最大等待时间,单位毫秒。
dataSource.setValidationQuery("SELECT 1");//用来检测连接是否有效的sql
dataSource.setTestOnBorrow(false);//申请连接时执行validationQuery检测连接是否有效
dataSource.setTestWhileIdle(true);//建议配置为true,不影响性能,并且保证安全性。
dataSource.setPoolPreparedStatements(false);//是否缓存preparedStatement,也就是PSCache
return dataSource;
}
}
ok这样就算自己配置了一个DataSource,Spring Boot会智能地选择我们自己配置的这个DataSource实例。
脚本初始化
CREATE DATABASE /*!32312 IF NOT EXISTS*/`spring` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `spring`;
DROP TABLE IF EXISTS `learn_resource`;
CREATE TABLE `learn_resource` (
`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`author` varchar(20) DEFAULT NULL COMMENT '作者',
`title` varchar(100) DEFAULT NULL COMMENT '描述',
`url` varchar(100) DEFAULT NULL COMMENT '地址链接',
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=1029 DEFAULT CHARSET=utf8;
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (999,'官方SpriongBoot例子','官方SpriongBoot例子','https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples');
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (1000,'龙果学院','Spring Boot 教程系列学习','http://www.roncoo.com/article/detail/124661');
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (1001,'嘟嘟MD独立博客','Spring Boot干货系列','http://tengj.top/');
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (1002,'后端编程嘟','Spring Boot视频教程','http://www.toutiao.com/m1559096720023553/');
开始使用JdbcTemplate
Spring的JdbcTemplate是自动配置的,你可以直接使用@Autowired
来注入到你自己的bean中来使用。这里博主做了一套基本的增删改查操作。
实体对象
public class LearnResouce {
private Long id;
private String author;
private String title;
private String url;
// SET和GET方法
}
Controller层
@Controller
@RequestMapping("/learn")
public class LearnController {
@Autowired
private LearnService learnService;
private Logger logger = LoggerFactory.getLogger(this.getClass());
@RequestMapping("")
public String learn(){
return "learn-resource";
}
@RequestMapping(value = "/queryLeanList",method = RequestMethod.POST,produces="application/json;charset=UTF-8")
@ResponseBody
public void queryLearnList(HttpServletRequest request ,HttpServletResponse response){
String page = request.getParameter("page"); // 取得当前页数,注意这是jqgrid自身的参数
String rows = request.getParameter("rows"); // 取得每页显示行数,,注意这是jqgrid自身的参数
String author = request.getParameter("author");
String title = request.getParameter("title");
Map<String,Object> params = new HashMap<String,Object>();
params.put("page", page);
params.put("rows", rows);
params.put("author", author);
params.put("title", title);
Page pageObj =learnService.queryLearnResouceList(params);
List<Map<String, Object>> learnList=pageObj.getResultList();
JSONObject jo=new JSONObject();
jo.put("rows", learnList);
jo.put("total", pageObj.getTotalPages());
jo.put("records", pageObj.getTotalRows());
ServletUtil.createSuccessResponse(200, jo, response);
}
/**
* 新添教程
* @param request
* @param response
*/
@RequestMapping(value = "/add",method = RequestMethod.POST)
public void addLearn(HttpServletRequest request , HttpServletResponse response){
JSONObject result=new JSONObject();
String author = request.getParameter("author");
String title = request.getParameter("title");
String url = request.getParameter("url");
if(StringUtil.isNull(author)){
result.put("message","作者不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(StringUtil.isNull(title)){
result.put("message","教程名称不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(StringUtil.isNull(url)){
result.put("message","地址不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
LearnResouce learnResouce = new LearnResouce();
learnResouce.setAuthor(author);
learnResouce.setTitle(title);
learnResouce.setUrl(url);
int index=learnService.add(learnResouce);
System.out.println("结果="+index);
if(index>0){
result.put("message","教程信息添加成功!");
result.put("flag",true);
}else{
result.put("message","教程信息添加失败!");
result.put("flag",false);
}
ServletUtil.createSuccessResponse(200, result, response);
}
/**
* 修改教程
* @param request
* @param response
*/
@RequestMapping(value = "/update",method = RequestMethod.POST)
public void updateLearn(HttpServletRequest request , HttpServletResponse response){
JSONObject result=new JSONObject();
String id = request.getParameter("id");
LearnResouce learnResouce=learnService.queryLearnResouceById(Long.valueOf(id));
String author = request.getParameter("author");
String title = request.getParameter("title");
String url = request.getParameter("url");
if(StringUtil.isNull(author)){
result.put("message","作者不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(StringUtil.isNull(title)){
result.put("message","教程名称不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(StringUtil.isNull(url)){
result.put("message","地址不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
learnResouce.setAuthor(author);
learnResouce.setTitle(title);
learnResouce.setUrl(url);
int index=learnService.update(learnResouce);
System.out.println("修改结果="+index);
if(index>0){
result.put("message","教程信息修改成功!");
result.put("flag",true);
}else{
result.put("message","教程信息修改失败!");
result.put("flag",false);
}
ServletUtil.createSuccessResponse(200, result, response);
}
/**
* 删除教程
* @param request
* @param response
*/
@RequestMapping(value="/delete",method = RequestMethod.POST)
@ResponseBody
public void deleteUser(HttpServletRequest request ,HttpServletResponse response){
String ids = request.getParameter("ids");
System.out.println("ids==="+ids);
JSONObject result = new JSONObject();
//删除操作
int index = learnService.deleteByIds(ids);
if(index>0){
result.put("message","教程信息删除成功!");
result.put("flag",true);
}else{
result.put("message","教程信息删除失败!");
result.put("flag",false);
}
ServletUtil.createSuccessResponse(200, result, response);
}
}
Service层
public interface LearnService {
int add(LearnResouce learnResouce);
int update(LearnResouce learnResouce);
int deleteByIds(String ids);
LearnResouce queryLearnResouceById(Long learnResouce);
Page queryLearnResouceList(Map<String,Object> params);
}
实现类
@Service
public class LearnServiceImpl implements LearnService {
@Autowired
LearnDao learnDao;
@Override
public int add(LearnResouce learnResouce) {
return this.learnDao.add(learnResouce);
}
@Override
public int update(LearnResouce learnResouce) {
return this.learnDao.update(learnResouce);
}
@Override
public int deleteByIds(String ids) {
return this.learnDao.deleteByIds(ids);
}
@Override
public LearnResouce queryLearnResouceById(Long id) {
return this.learnDao.queryLearnResouceById(id);
}
@Override
public Page queryLearnResouceList(Map<String,Object> params) {
return this.learnDao.queryLearnResouceList(params);
}
}
Dao层
public interface LearnDao {
int add(LearnResouce learnResouce);
int update(LearnResouce learnResouce);
int deleteByIds(String ids);
LearnResouce queryLearnResouceById(Long id);
Page queryLearnResouceList(Map<String,Object> params);
}
实现类,这里注入我们需要的JdbcTemplate
@Repository
public class LearnDaoImpl implements LearnDao{
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
public int add(LearnResouce learnResouce) {
return jdbcTemplate.update("insert into learn_resource(author, title,url) values(?, ?, ?)",learnResouce.getAuthor(),learnResouce.getTitle(),learnResouce.getUrl());
}
@Override
public int update(LearnResouce learnResouce) {
return jdbcTemplate.update("update learn_resource set author=?,title=?,url=? where id = ?",new Object[]{learnResouce.getAuthor(),learnResouce.getTitle(),learnResouce.getUrl(),learnResouce.getId()});
}
@Override
public int deleteByIds(String ids){
return jdbcTemplate.update("delete from learn_resource where id in("+ids+")");
}
@Override
public LearnResouce queryLearnResouceById(Long id) {
List<LearnResouce> list = jdbcTemplate.query("select * from learn_resource where id = ?", new Object[]{id}, new BeanPropertyRowMapper(LearnResouce.class));
if(null != list && list.size()>0){
LearnResouce learnResouce = list.get(0);
return learnResouce;
}else{
return null;
}
}
@Override
public Page queryLearnResouceList(Map<String,Object> params) {
StringBuffer sql =new StringBuffer();
sql.append("select * from learn_resource where 1=1");
if(!StringUtil.isNull((String)params.get("author"))){
sql.append(" and author like '%").append((String)params.get("author")).append("%'");
}
if(!StringUtil.isNull((String)params.get("title"))){
sql.append(" and title like '%").append((String)params.get("title")).append("%'");
}
Page page = new Page(sql.toString(), Integer.parseInt(params.get("page").toString()), Integer.parseInt(params.get("rows").toString()), jdbcTemplate);
return page;
}
}
上面介绍的JdbcTemplate
只是最基本的几个操作,更多其他数据访问操作的使用请参考:JdbcTemplate API
到此为止,后端交互代码都写好了,这里博主整合的bootstrap模板就不展示了,各位可以自行下载本篇对应的源码跑起来看看,效果很棒咯,如下:
总结
SpringBoot下访问数据库还是很简单的,只要添加依赖,然后在application.properties中配置连接信息。下一篇博主将介绍下Spring Boot对mybatis的整合。
想要查看更多Spring Boot干货教程,可前往:Spring Boot干货系列总纲
源码下载
( ̄︶ ̄)↗[相关示例完整代码]
想要ace模板源码的话,在博主公众号(点头像即可看到公众号)回复关键字:ace
一直觉得自己写的不是技术,而是情怀,一篇篇文章是自己这一路走来的痕迹。靠专业技能的成功是最具可复制性的,希望我的这条路能让你少走弯路,希望我能帮你抹去知识的蒙尘,希望我能帮你理清知识的脉络,希望未来技术之巅上有你也有我,希望大爷你看完打赏点零花钱给我。