Spring的數(shù)據(jù)庫編程淺入淺出
前言
先入門,把核心理解后再回過頭來看這些我覺得效果更好,不知道說的對不對,要是理解不當,還望指教。此篇為Spring的數(shù)據(jù)庫編程,主要講jdbcTemplate,讓初學者直接上手。
數(shù)據(jù)庫切入
數(shù)據(jù)庫編程是互聯(lián)網(wǎng)編程的基礎,Spring框架為開發(fā)者提供了JDBC模板模式,即jdbcTemplate,它可以簡化許多代碼,需要提醒的是jdbcTemplate在實際應用中并不常用,但我覺得對新手來說蒼蠅再小也是肉,要想往前走,就得把這些小肉先吃了。
Spring JDBC配置
使用Spring JDBC操作數(shù)據(jù)庫,需要對其進行配置,配置如下
- <!--配置spring-jdbcTemplate-->
- <!--配置數(shù)據(jù)源-->
- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
- <!--MySQL數(shù)據(jù)庫驅動-->
- <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
- <!--連接數(shù)據(jù)庫的URL-->
- <property name="url" value="jdbc:mysql://localhost:3306/bbb?useUnicode=true&characterEncoding=UTF-8"></property>
- <!--連接數(shù)據(jù)庫的用戶名-->
- <property name="username" value="root"></property>
- <!--連接數(shù)據(jù)庫的密碼-->
- <property name="password" value="root"></property>
- </bean>
- <!--配置JDBC模板-->
- <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
- <property name="dataSource" ref="dataSource"></property>
- </bean>
配置JDBC模板時需要將dataSource注入到jdbcTemplate,而在數(shù)據(jù)訪問層(Dao類)需要使用jdbcTemplate時也需要將jdbc Template注入到對應的Bean中,我在這演示用最簡單的注解注入
- @Repository("userDao")
- public class UserDaoImpl implements UserDao {
- @Autowired
- //使用配置文件中的JDBC模板
- private JdbcTemplate jdbcTemplate;
- }
Spring Jdbc Template的常用方法
在上面我們獲取了JDBC模板,下面我來說如何使用它。首先需要了解JdbcTemplate常用的方法,該類的常用方法是update和query.
1、public int update(String sql,Object args[])
該方法可以對數(shù)據(jù)表進行增加、修改、刪除等操作。使用args[]設置SQL語句中的參數(shù),并返回更新的行數(shù)。
示例如下:
- public void add() {
- String insertSql = "insert into user values(null,?,?)";
- Object parem1[] = {"成功","123456"};
- jdbcTemplate.update(insertSql,parem1);
- System.out.println("UserDao中的添加功能實現(xiàn)了");
- }
2、public List
該方法可以對數(shù)據(jù)表進行查詢操作,rowMapper將結果集映射到用戶自定義的類中(前提是自定義類中的屬性要與數(shù)據(jù)表的字段對應)。
示例如下:
- public void query() {
- String selectSql = "select * from user";
- RowMapper<User> rowMapper = new BeanPropertyRowMapper<User>(User.class);
- List<User> list = jdbcTemplate.query(selectSql,rowMapper,null);
- System.out.println("UserDao中的查詢功能實現(xiàn)了");
- }
案例輔助
Pom.xml
- <dependencies>
- <dependency>
- <groupId>junit</groupId>
- <artifactId>junit</artifactId>
- <version>4.11</version>
- <scope>test</scope>
- </dependency>
- <dependency>
- <groupId>javax.servlet</groupId>
- <artifactId>javax.servlet-api</artifactId>
- <version>3.1.0</version>
- </dependency>
- <dependency>
- <groupId>javax.servlet</groupId>
- <artifactId>jstl</artifactId>
- <version>1.2</version>
- </dependency>
- <dependency>
- <groupId>mysql</groupId>
- <artifactId>mysql-connector-java</artifactId>
- <version>5.1.38</version>
- </dependency>
- <!--spring核心依賴-->
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-core</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-beans</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-context</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-aop</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-jdbc</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-web</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-webmvc</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-expression</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <dependency>
- <groupId>org.springframework</groupId>
- <artifactId>spring-tx</artifactId>
- <version>5.1.5.RELEASE</version>
- </dependency>
- <!--日志相關-->
- <dependency>
- <groupId>commons-logging</groupId>
- <artifactId>commons-logging</artifactId>
- <version>1.2</version>
- </dependency>
- </dependencies>
spring-config.xml
- <?xml version="1.0" encoding="UTF-8"?>
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xmlns:context="http://www.springframework.org/schema/context"
- xmlns:tx="http://www.springframework.org/schema/tx"
- xmlns:mvc="http://www.springframework.org/schema/mvc"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans.xsd
- http://www.springframework.org/schema/context
- http://www.springframework.org/schema/context/spring-context.xsd
- http://www.springframework.org/schema/tx
- http://www.springframework.org/schema/tx/spring-tx.xsd
- http://www.springframework.org/schema/mvc
- http://www.springframework.org/schema/mvc/spring-mvc.xsd
- ">
- <!--配置注解要掃描的包-->
- <context:component-scan base-package="com.my"></context:component-scan>
- <mvc:annotation-driven></mvc:annotation-driven>
- <!--將指定類TestDaoImpl配置給Spring,讓Spring創(chuàng)建其實例-->
- <bean id="testDIDao" class="com.my.dao.impl.TestDaoImpl"/>
- <!--使用構造方法注入-->
- <!--<bean id="testDIService" class="com.my.service.impl.TestServiceImpl" >-->
- <!--<!–將TestDIDao注入到TestDIServiceImpl類的屬性testDao上–>-->
- <!--<constructor-arg index="0" ref="testDIDao"/>-->
- <!--</bean>-->
- <!--使用setter方法注入-->
- <bean id="testDIService" class="com.my.service.impl.TestServiceImpl">
- <!--調用TestDIServiceImpl類的setter方法,將TestDao注入到TestServiceImpl類的屬性testDao上-->
- <property name="testDao" ref="testDIDao"></property>
- </bean>
- <!--配置spring-jdbcTemplate-->
- <!--配置數(shù)據(jù)源-->
- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
- <!--MySQL數(shù)據(jù)庫驅動-->
- <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
- <!--連接數(shù)據(jù)庫的URL-->
- <property name="url" value="jdbc:mysql://localhost:3306/bbb?useUnicode=true&characterEncoding=UTF-8"></property>
- <!--連接數(shù)據(jù)庫的用戶名-->
- <property name="username" value="root"></property>
- <!--連接數(shù)據(jù)庫的密碼-->
- <property name="password" value="root"></property>
- </bean>
- <!--配置JDBC模板-->
- <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
- <property name="dataSource" ref="dataSource"></property>
- </bean>
- <!--配置事務-->
- <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
- <property name="dataSource" ref="dataSource"></property>
- </bean>
- <!--注冊事務注解驅動-->
- <tx:annotation-driven transaction-manager="txManager"></tx:annotation-driven>
- </beans>
User
- package com.my.pojo;
- public class User {
- private int id;
- private String username;
- private String password;
- public User() {
- }
- public User(int id, String username, String password) {
- this.id = id;
- this.username = username;
- this.password = password;
- }
- public int getId() {
- return id;
- }
- public void setId(int id) {
- this.id = id;
- }
- public String getUsername() {
- return username;
- }
- public void setUsername(String username) {
- this.username = username;
- }
- public String getPassword() {
- return password;
- }
- public void setPassword(String password) {
- this.password = password;
- }
- @Override
- public String toString() {
- return "User{" +
- "id=" + id +
- ", username='" + username + ''' +
- ", password='" + password + ''' +
- '}';
- }
- }
UserDao
- package com.my.dao;
- public interface UserDao {
- public void add();
- public void delete();
- public void update();
- public void query();
- }
UserDaoImpl
- @Override
- public void update() {
- String updateSql = "update user set username=? , password=? where id =?";
- Object parem3[] = {"修改","654321",3};
- jdbcTemplate.update(updateSql,parem3);
- System.out.println("UserDao中的修改功能實現(xiàn)了");
- }
- @Override
- public void query() {
- String selectSql = "select * from user";
- RowMapper<User> rowMapper = new BeanPropertyRowMapper<User>(User.class);
- List<User> list = jdbcTemplate.query(selectSql,rowMapper,null);
- System.out.println("UserDao中的查詢功能實現(xiàn)了");
- for (User user : list){
- System.out.println(user);
- }
- }
- }
測試Test3
- package com.my.test;
- import com.my.dao.UserDao;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.context.ApplicationContext;
- import org.springframework.context.support.ClassPathXmlApplicationContext;
- public class Test3 {
- @Autowired
- private UserDao userDao;
- public static void main(String[] args) {
- ApplicationContext appCon = new ClassPathXmlApplicationContext("spring-config.xml");
- //從容器中獲取目標對象
- UserDao userDao = (UserDao) appCon.getBean("userDao");
- //userDao.add();
- userDao.delete();
- userDao.update();
- userDao.query();
- }
- }
測試結果
結束
對于Spring JbdcTemplate的講解到此結束,對于新手來說沒必要太復雜,能完成增刪改查做個入門即可,等了解了再詳細學習才有幫助,希望能對一些需要的朋友有用吧。