1.pom 依赖
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<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.37</version>
</dependency>
</dependencies>
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2.连接测试
2.1 Test01.java
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package com.forsre.jdbc;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.util.Properties;
public class Test01 {
public static void main(String[] args) {
try {
//1.提供java.sql.Driver接口实现类的对象
Driver driver = null;
driver = new com.mysql.jdbc.Driver();
//2.提供url，指明具体操作的数据
String url = "jdbc:mysql://192.168.8.161/hql";
//3.提供Properties的对象，指明用户名和密码
Properties info = new Properties();
info.setProperty("user", "root");
info.setProperty("password", "000000");
//4.调用driver的connect()，获取连接
Connection conn = driver.connect(url, info);
System.out.println(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
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2.2 Test02.java
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package com.forsre.jdbc;
import java.sql.Connection;
import java.sql.Driver;
import java.util.Properties;
public class Test02 {
public static void main(String[] args) {
try {
//1.实例化Driver
String className = "com.mysql.jdbc.Driver";
Class clazz = Class.forName(className);
Driver driver = (Driver) clazz.newInstance();
//2.提供url，指明具体操作的数据
String url = "jdbc:mysql://192.168.8.161:3306/hql";
//3.提供Properties的对象，指明用户名和密码
Properties info = new Properties();
info.setProperty("user", "root");
info.setProperty("password", "000000");
//4.调用driver的connect()，获取连接
Connection conn = driver.connect(url, info);
System.out.println(conn);
} catch (Exception e) {
e.printStackTrace();
}
}
}
/*
说明：相较于方式一，这里使用反射实例化Driver，不在代码中体现第三方数据库的API。体现了面向接口编程思想。
*/
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2.3 Test03.java
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package com.forsre.jdbc;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
public class Test03 {
public static void main(String[] args) {
try {
//1.数据库连接的4个基本要素：
String url = "jdbc:mysql://192.168.8.161:3306/hql";
String user = "root";
String password = "000000";
String driverName = "com.mysql.jdbc.Driver";
//2.实例化Driver
Class clazz = Class.forName(driverName);
Driver driver = (Driver) clazz.newInstance();
//3.注册驱动
DriverManager.registerDriver(driver);
//4.获取连接
Connection conn = DriverManager.getConnection(url, user, password);
System.out.println(conn);
} catch (Exception e) {
e.printStackTrace();
}
}
}
/*
说明：使用DriverManager实现数据库的连接。体会获取连接必要的4个基本要素。
*/
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2.4 Test04java
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package com.forsre.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
public class Test04 {
public static void main(String[] args) {
try {
//1.数据库连接的4个基本要素：
String url = "jdbc:mysql://192.168.8.161:3306/hql";
String user = "root";
String password = "000000";
String driverName = "com.mysql.jdbc.Driver";
//2.加载驱动 （①实例化Driver ②注册驱动）
Class.forName(driverName);
//Driver driver = (Driver) clazz.newInstance();
//3.注册驱动
//DriverManager.registerDriver(driver);
/*
可以注释掉上述代码的原因，是因为在mysql的Driver类中声明有：
static {
try {
DriverManager.registerDriver(new Driver());
} catch (SQLException var1) {
throw new RuntimeException("Can't register driver!");
}
}
*/
//3.获取连接
Connection conn = DriverManager.getConnection(url, user, password);
System.out.println(conn);
} catch (Exception e) {
e.printStackTrace();
}
}
}
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说明：不必显式的注册驱动了。因为在DriverManager的源码中已经存在静态代码块，实现了驱动的注册。
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public class Driver extends NonRegisteringDriver implements java.sql.Driver {
//
// Register ourselves with the DriverManager
//
static {
try {
java.sql.DriverManager.registerDriver(new Driver());
} catch (SQLException E) {
throw new RuntimeException("Can't register driver!");
}
}
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2.5 Test05.java
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package com.forsre.jdbc;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Properties;
public class Test05 {
public static void main(String[] args) throws Exception {
//1.加载配置文件
InputStream is = Test05.class.getClassLoader().getResourceAsStream("jdbc.properties");
Properties pros = new Properties();
pros.load(is);
//2.读取配置信息
String user = pros.getProperty("user");
String password = pros.getProperty("password");
String url = pros.getProperty("url");
String driverClass = pros.getProperty("driverClass");
//3.加载驱动
Class.forName(driverClass);
//4.获取连接
Connection conn = DriverManager.getConnection(url, user, password);
System.out.println(conn);
}
}
/*
说明：使用配置文件的方式保存配置信息，在代码中加载配置文件
**使用配置文件的好处：**
①实现了代码和数据的分离，如果需要修改配置信息，直接在配置文件中修改，不需要深入代码
②如果修改了配置信息，省去重新编译的过程。
*/
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#jdbc.properties
#放置至src/main/resources目录内
user=root
password=000000
url=jdbc:mysql://192.168.8.161:3306/hql
driverClass=com.mysql.jdbc.Driver
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