SpringBoot 学习——使用 JdbcTemplate 访问数据库
参考博客：
[1] Spring Boot干货系列：（八）数据存储篇-SQL关系型数据库之JdbcTemplate的使用
[2] 一起来学 SpringBoot 2.x | 第五篇：使用 JdbcTemplate 访问数据库
添加依赖
org.springframework.boot
spring-boot-starter-jdbc
mysql
mysql-connector-java
数据源配置
在application.properties中添加如下配置。值得注意的是，SpringBoot默认会自动配置DataSource，它将优先采用HikariCP连接池，如果没有该依赖的情况则选取tomcat-jdbc，如果前两者都不可用最后选取Commons DBCP2。通过spring.datasource.type属性可以指定其它种类的连接池。
spring.datasource.url = jdbc:mysql://localhost:3306/spring?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.username = root
spring.datasource.password = root0
spring.datasource.driver-class-name = com.mysql.cj.jdbc.Driver
#spring.datasource.type
#更多细微的配置可以通过下列前缀进行调整
#spring.datasource.hikari
#spring.datasource.tomcat
#spring.datasource.dbcp2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。
实体对象：
public class LearnResource {
private Long id;
private String author;
private String title;
private String url;
//get & set 方法
//...
}Controller层：
@Controller
@RequestMapping("/learn")
public class LearnController {
@Autowired
private LearnService learnService;
@RequestMapping("t")
public String learn(){
return "learn-resource";
}
@RequestMapping(value = "queryLearnList",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 params = new HashMap();
params.put("page", page);
params.put("rows", rows);
params.put("author", author);
params.put("title", title);
Page pageObj =learnService.queryLearnResourceList(params);
List> 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(author.isEmpty()){
result.put("message","作者不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(title.isEmpty()){
result.put("message","教程名称不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
if(url.isEmpty()){
result.put("message","地址不能为空!");
result.put("flag",false);
ServletUtil.createSuccessResponse(200, result, response);
return;
}
LearnResource learnResource = new LearnResource();
learnResource.setAuthor(author);
learnResource.setTitle(title);
learnResource.setUrl(url);
int index=learnService.add(learnResource);
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);
}
/**
* 删除教程
* @param request
* @param response
*/
@RequestMapping(value="delete",method = RequestMethod.POST)
@ResponseBody
public void deleteUser(HttpServletRequest request ,HttpServletResponse response){
String id = request.getParameter("id");
System.out.println("id==="+id);
JSONObject result = new JSONObject();
//删除操作
int index = learnService.delete(id);
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 接口和实现：
public interface LearnService {
int add(LearnResource learnResource);
int delete(String id);
Page queryLearnResourceList(Map params);
} @Service
public class LearnServiceImpl implements LearnService {
@Autowired
LearnDao learnDao;
@Override
public int add(LearnResource learnResource) {
return this.learnDao.add(learnResource);
}
@Override
public int delete(String id) {
return this.learnDao.delete(id);
}
@Override
public Page queryLearnResourceList(Map params) {
return this.learnDao.queryLearnResourceList(params);
}
} Dao层 接口和实现：
public interface LearnDao {
int add(LearnResource learnResource);
int delete(String id);
Page queryLearnResourceList(Map params);
} @Repository
public class LearnDaoImpl implements LearnDao {
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
public int add(LearnResource learnResource) {
return jdbcTemplate.update("insert into learn_resource(author,title,url) values(?, ?, ?)",learnResource.getAuthor(),learnResource.getTitle(),learnResource.getUrl());
}
@Override
public int delete(String id) {
return jdbcTemplate.update("delete from learn_resource where id = ?", id);
}
@Override
public Page queryLearnResourceList(Map 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
结果展示：
