- A durable layer technology
- Two, JdbcTemplate
- Three, Hibernate
- Four, MyBatis
A durable layer technology
- Spring comes with JdbcTemplate
- Hibernate
- Mybatis
Two, JdbcTemplate
Development steps:
1. Import associated jar package
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.1.5.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
</dependency>
Configuring connection pool (data source)
Creating a database test
- Spring default connection pool:
<!-- 配置Spring默认的连接池 -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/test"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
</bean>
- DBCP connection pool:
The introduction of Maven coordinates:
<!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp -->
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
Configuration information:
<!-- 配置DBCP连接池 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///test"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
</bean>
- C3P0 connection pool:
The introduction of Maven coordinates:
<!-- https://mvnrepository.com/artifact/c3p0/c3p0 -->
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
Configuration information:
<!-- 配置c3p0连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"/>
<property name="jdbcUrl" value="jdbc:mysql:///test"/>
<property name="user" value="root"/>
<property name="password" value="123"/>
</bean>
The parameter is set to the properties file:
Properties file jdbc.properties
:
jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql:///test
jdbc.user = root
jdbc.password = 123
You need to use the content attribute configuration file in the applicationContext.xml .
- The first written:
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="classpath:jdbc.properties"></property>
</bean>
- The second writing:
We need to introduce namespace context of:
<?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"
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">
Configuration is as follows:
<context:property-placeholder location="classpath:jdbc.properties"/>
The above configuration of the data source, the value of the property can be used } {$ is taken out properties values in the configuration file
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.user}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
3. Create a table
It should be noted here is to create a table name not be used users
,
CREATE TABLE `member` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(20) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB
4. Write the entity class
public class Member {
private Integer id;
private String name;
private Integer age;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Member [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}
5. Dao layer implements
5.1 Inheritance JdbcDaoSupport
Spring framework provides technical support for the persistence layer classes: JdbcDaoSupport , this class depend on the JdbcTemplte templates and implement their own setter method
DAO when writing to extend this class, as follows:
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import com.hao.entity.Member;
public class MemberDao extends JdbcDaoSupport {
/**
* 添加用户
*
* @param member
*/
public void add(Member member) {
String sql = "insert into member values(null,?,?)";
this.getJdbcTemplate().update(sql, member.getName(), member.getAge());
}
/**
* 根据id更新用户名
*
* @param member
*/
public void updateById(Member member) {
String sql = "update member set name = ? where id =?";
this.getJdbcTemplate().update(sql, member.getName(), member.getId());
}
/**
* 根据id删除用户
*
* @param member
*/
public void deleteById(Member member) {
String sql = "delete from member where id = ? ";
this.getJdbcTemplate().update(sql, member.getId());
}
/**
* 查询用户总数
*
* @return
*/
public int findCount() {
String sql = "select count(*) from member";
// spring 3.2之后的版本不在支持queryInt(sql);
return this.getJdbcTemplate().queryForObject(sql, int.class);
}
/**
* 通过id查询用户名
*
* @param id
* @return
*/
public String findNameById(int id) {
String sql = "select name from member where id = ?";
return this.getJdbcTemplate().queryForObject(sql, String.class, id);
}
/**
* 根据id查询用户
*
* @param id
* @return
*/
public Member findById(int id) {
String sql = "select * from member where id = ?";
Member member = this.getJdbcTemplate().queryForObject(sql, new UserRowMapper(), id);
return member;
}
/**
* 查询所有用户
*
* @return
*/
public List<Member> findAll() {
String sql = "select * from member";
return this.getJdbcTemplate().query(sql, new UserRowMapper());
}
class UserRowMapper implements RowMapper<Member> {
/**
* rs:结果集. rowNum:行号
*/
public Member mapRow(ResultSet rs, int rowNum) throws SQLException {
Member member = new Member();
member.setId(rs.getInt("id"));
member.setName(rs.getString("name"));
return member;
}
}
}
In XML configuration, this embodiment does not need to declare the jdbcTemplate XML, only data source Dao injection layer can be as follows:
<context:property-placeholder location="classpath:jdbc.properties"/>
<!-- 配置c3p0连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.user}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<!-- 此处直接注入数据源,因为Dao层中继承了JdbcDaoSupport这个类 -->
<bean id="memberDao" class="com.hao.dao.MemberDao">
<property name="dataSource" ref="dataSource"></property>
</bean>
5.2 direct injection JdbcTmplate
public class MemberDaoForNoExtend {
//利用setter的方法注入jdbcTmplate
private JdbcTemplate jdbcTemplate;
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
/**
* 添加用户
*
* @param member
*/
public void add(Member member) {
String sql = "insert into member values(null,?,?)";
jdbcTemplate.update(sql, member.getName(), member.getAge());
}
// 后面的代码省略...
}
In the XML configuration , in such a manner to be injected jdbcTemplate layer Dao
<!-- 定义jdbctemplate 需要注入数据源 -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
<!-- 定义Dao层类 需要注入jdbcTemplate-->
<bean id="memberDao" class="com.hao.dao.MemberDao">
<property name="jdbcTemplate" ref="jdbcTemplate"></property>
</bean>
6. Test
Test 1 -> 5.1 in test mode
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import com.hao.dao.MemberDao;
import com.hao.entity.Member;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext1.xml")
public class JDBCTest1 {
@Autowired
@Qualifier("memberDao")
private MemberDao memberDao;
@Test
public void test1() {
Member member = new Member();
member.setName("小涛");
member.setAge(23);
memberDao.add(member);
}
@Test
public void test2() {
int findCount = memberDao.findCount();
System.out.println(findCount);
}
@Test
public void test3() {
Member member = new Member();
member.setId(12);
memberDao.deleteById(member);
}
}
Test 2 -> 5.2 in test mode
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext2.xml")
public class JDBCTest2 {
@Autowired
@Qualifier("memberDaoForNoExtend")
private MemberDaoForNoExtend memberDaoForNoExtend;
@Test
public void test1() {
Member member = new Member();
member.setName("小明");
member.setAge(23);
memberDaoForNoExtend.add(member);
}
}
JdbcTemplate of CRUD (to be finishing)
- Storage:
update(String sql,Object... args)
- modify:
update(String sql,Object... args)
- delete:
update(String sql,Object... args)
- Inquire:
- Simple query:
queryForObject(String sql,Class clazz,Object... args)
;
- :( complex queries return objects, and collections of objects)
queryForObjectString sql,RowMapper<T> rowMapper,Object... args);
query(String sql,RowMapper<T> rowMapper,Object... args);
- Simple query:
Three, Hibernate
org.springframework.orm.hibernate3.support.HibernateDaoSupport
Four, MyBatis
org.springframework.orm.ibatis.support.SqlMapClientDaoSupport