Spring Boot乾貨系列：（八）數據存儲篇-SQL關係型數據庫之JdbcTemplate的使用

時間 2019-12-08

標籤 spring boot 乾貨系列數據存儲 sql 關係數據庫 jdbctemplate 使用欄目 Spring 简体版

原文原文鏈接

前言

前面幾章介紹了一些基礎，但都是靜態的，還不足以構建一個動態的應用。本篇開始就要介紹數據交互了，爲了演示效果更加好，博主花了大把時間整合了一個後端模板框架，基於Bootstrap3的ACE模板，並實現了一個基本的增刪改查分頁功能。讓咱們一塊兒動手，學技術的同時，順便把咱們的項目完善起來，這樣跟着博主學到最後，你就有了一個屬於本身的Spring Boot項目啦。html

正文

本文介紹在Spring Boot基礎下配置數據源和經過JdbcTemplate編寫數據訪問的示例。java

添加依賴

這裏須要添加spring-boot-starter-jdbc依賴跟mysql依賴mysql

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

數據源配置 git

在src/main/resources/application.properties中配置數據源信息。github

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

spring-boot-starter-jdbc 默認使用tomcat-jdbc數據源，若是你想使用其餘的數據源，好比這裏使用了阿里巴巴的數據池管理,你應該額外添加如下依賴：自定義數據源

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.19</version>
</dependency>

修改Application.java spring

@SpringBootApplication
public class Application {

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

    @Autowired
    private Environment env;

    //destroy-method="close"的做用是當數據庫鏈接不使用的時候,就把該鏈接從新放到數據池中,方便下次使用調用.
    @Bean(destroyMethod =  "close")
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl(env.getProperty("spring.datasource.url"));
        dataSource.setUsername(env.getProperty("spring.datasource.username"));//用戶名
        dataSource.setPassword(env.getProperty("spring.datasource.password"));//密碼
        dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
        dataSource.setInitialSize(2);//初始化時創建物理鏈接的個數
        dataSource.setMaxActive(20);//最大鏈接池數量
        dataSource.setMinIdle(0);//最小鏈接池數量
        dataSource.setMaxWait(60000);//獲取鏈接時最大等待時間，單位毫秒。
        dataSource.setValidationQuery("SELECT 1");//用來檢測鏈接是否有效的sql
        dataSource.setTestOnBorrow(false);//申請鏈接時執行validationQuery檢測鏈接是否有效
        dataSource.setTestWhileIdle(true);//建議配置爲true，不影響性能，而且保證安全性。
        dataSource.setPoolPreparedStatements(false);//是否緩存preparedStatement，也就是PSCache
        return dataSource;
    }
}

ok這樣就算本身配置了一個DataSource，Spring Boot會智能地選擇咱們本身配置的這個DataSource實例。sql

腳本初始化

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 '做者',
  `title` varchar(100) DEFAULT NULL COMMENT '描述',
  `url` varchar(100) DEFAULT NULL COMMENT '地址連接',
  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,'龍果學院','Spring Boot 教程系列學習','http://www.roncoo.com/article/detail/124661');
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (1001,'嘟嘟MD獨立博客','Spring Boot乾貨系列','http://tengj.top/');
insert into `learn_resource`(`id`,`author`,`title`,`url`) values (1002,'後端編程嘟','Spring Boot視頻教程','http://www.toutiao.com/m1559096720023553/');

開始使用JdbcTemplate

Spring的JdbcTemplate是自動配置的，你能夠直接使用@Autowired來注入到你本身的bean中來使用。這裏博主作了一套基本的增刪改查操做。數據庫

實體對象

public class LearnResouce {
    private Long id;
    private String author;
    private String title;
    private String url;
    // SET和GET方法
}

Controller層

@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"); // 取得當前頁數,注意這是jqgrid自身的參數
        String rows = request.getParameter("rows"); // 取得每頁顯示行數，,注意這是jqgrid自身的參數
        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","做者不能爲空!");
            result.put("flag",false);
            ServletUtil.createSuccessResponse(200, result, response);
            return;
        }
        if(StringUtil.isNull(title)){
            result.put("message","教程名稱不能爲空!");
            result.put("flag",false);
            ServletUtil.createSuccessResponse(200, result, response);
            return;
        }
        if(StringUtil.isNull(url)){
            result.put("message","地址不能爲空!");
            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("結果="+index);
        if(index>0){
            result.put("message","教程信息添加成功!");
            result.put("flag",true);
        }else{
            result.put("message","教程信息添加失敗!");
            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","做者不能爲空!");
            result.put("flag",false);
            ServletUtil.createSuccessResponse(200, result, response);
            return;
        }
        if(StringUtil.isNull(title)){
            result.put("message","教程名稱不能爲空!");
            result.put("flag",false);
            ServletUtil.createSuccessResponse(200, result, response);
            return;
        }
        if(StringUtil.isNull(url)){
            result.put("message","地址不能爲空!");
            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("修改結果="+index);
        if(index>0){
            result.put("message","教程信息修改爲功!");
            result.put("flag",true);
        }else{
            result.put("message","教程信息修改失敗!");
            result.put("flag",false);
        }
        ServletUtil.createSuccessResponse(200, result, response);
    }
    /**
     * 刪除教程
     * @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();
        //刪除操做
        int index = learnService.deleteByIds(ids);
        if(index>0){
            result.put("message","教程信息刪除成功!");
            result.put("flag",true);
        }else{
            result.put("message","教程信息刪除失敗!");
            result.put("flag",false);
        }
        ServletUtil.createSuccessResponse(200, result, response);
    }
}

Service層

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);
}

實現類編程

@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層 json

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);
}

實現類,這裏注入咱們須要的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;
    }
}