springBoot整合JdbcTemplate進行數據持久化的基本操作

什麼是JdbcTemplate？

JdbcTemplate是Spring的一部分,是對數據庫的操作在jdbc的封裝,處理了資源的建立和釋放(不需要我們管理連接了),我們只需要提供SQL語句(不需要我們設置參數了)和提取結果(查詢時候可以直接返回對應的實體類),使JDBC更加易於使用。
JdbcTemplate使用spring的注入功能，把DataSource註冊到JdbcTemplate之中。
spring源碼地址

爲什麼需要JdbcTemplate？
使用jdbc時,每次都需要自己獲取PreparedStatement，輸入sql語句參數，關閉連接等操作。造成操作冗餘。影響我們打代碼的效率。有了JDBCTemplate以後就可以只寫SQL語句就可以了。

JdbcTemplate的基本使用步驟

本教程使用的開發IED爲IDEA基於maven

1.pom.xml中引入相關依賴

對於JdbcTemplate的使用，除了基礎的spring依賴之外，需要的相關依賴有

1.mysql-connector
2.spring jdbc
3.druid

pom.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.mzc</groupId>
    <artifactId>infotest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>infotest</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.9</version>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2.編寫配置

application.properties文件如下：

server.port=8081
spring.application.name=travels

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/jdbctest?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=277171

數據庫有關的信息，例如spring.datasource.url、usename以及password,根據自己的實際情況進行配置

3.編寫持久層，這裏以Book進行舉例

Book.java

package com.mzc.Model;

/**
 * @author jikeMisma
 * @date 2020/6/19 - 10:51
 */
public class Book {

    int id;
    String bookname;
    String author;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getBookname() {
        return bookname;
    }

    public void setBookname(String bookname) {
        this.bookname = bookname;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }
}

4.編寫DAO層

BookDao.java

package com.mzc.Dao.impl;

import com.mzc.Model.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author jikeMisma
 * @date 2020/6/19 - 10:52
 */

@Repository
public class BookDao {


    @Autowired
    JdbcTemplate jdbcTemplate;

    public int addBook(Book book) {

        return jdbcTemplate.update("insert into t_book(bookname,author) values  (?,?)", book.getBookname(), book.getAuthor());
    }

    public int updateBook(Book book) {
        return jdbcTemplate.update("insert into t_book set bookname=?,author=? where id =?", book.getBookname(), book.getAuthor(), book.getId());
    }

    public int deleteBookBtId(Integer id) {
        return jdbcTemplate.update("delete from t_book where id=?", id);
    }


    public Book getBookById(Integer id){
        return  jdbcTemplate.queryForObject("select * from t_book where id=?",new BeanPropertyRowMapper<>(Book.class),id);

    }

    public List<Book> getAllBooks(){
        return jdbcTemplate.query("select * from t_book",new BeanPropertyRowMapper<>(Book.class));
    }


}

5.編寫Service層

BookService .java

package com.mzc.Service.impl;

import com.mzc.Dao.impl.BookDao;
import com.mzc.Model.Book;
import lombok.experimental.Accessors;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author jikeMisma
 * @date 2020/6/19 - 11:13
 */

@Service
public class BookService {


    @Autowired
    BookDao bookDao;

    public int addBook(Book book){
        return bookDao.addBook(book);
    }

    public int updateBook(Book book){
        return bookDao.updateBook(book);
    }

    public int deleteBookBtId(Integer id){
        return bookDao.deleteBookBtId(id);
    }

    public Book getBookById(Integer id){
        return bookDao.getBookById(id);
    }

    public List<Book> getAllBooks(){
        return bookDao.getAllBooks();
    }
}

6.創建Controller進行調用

package com.mzc.Controller;

import com.mzc.Model.Book;
import com.mzc.Service.impl.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

/**
 * @author jikeMisma
 * @date 2020/6/19 - 11:16
 */
@Controller
public class BookController {


    @Autowired
    BookService bookService;

    @GetMapping("bookOps")
    public void bookOps(){
        Book b1 = new Book();
        b1.setBookname("Redis設計與實現");
        b1.setAuthor("黃健宏");
        int i = bookService.addBook(b1);
        System.out.println("addBood>>>"+i);

        Book b2 = new Book();
        b2.setBookname("大數據技術原理與應用");
        b2.setAuthor("林子雨");
        int updatebook = bookService.addBook(b2);
        System.out.println("updateBook>>>"+updatebook);

        Book b3 = bookService.getBookById(5);
        System.out.println("getBookByid>>>"+b3);

    }
}

這時候編寫的數據就可以寫入數據庫進行持久化了。

運行截圖如下

啓動springBoot項目

在瀏覽器訪問對應的地址

查看數據庫數據是否入庫：