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数据库准备
CREATE DATABASE dbutils_learn;
USE dbutils_learn;
create table account(
id int primary key auto_increment,
name varchar(50),
money double
);
insert into account(name,money) values('aaa',1000);
insert into account(name,money) values('bbb',1000);
insert into account(name,money) values('ccc',1000);
SELECT * FROM account;
c3p0的配置文件
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/2002/xmlspec/dtd/2.10/xmlspec.dtd">
<c3p0-config>
<default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/dbutils_learn</property>
<property name="user">root</property>
<property name="password">123456</property>
<property name="initialPoolSize">10</property>
<property name="maxIdleTime">30</property>
<property name="maxPoolSize">100</property>
<property name="minPoolSize">10</property>
</default-config>
</c3p0-config>
c3p0utils.java
public class C3P0Utils {
private static DataSource ds=new ComboPooledDataSource();
public static Connection getConnection() throws SQLException{
return ds.getConnection();
}
public static void closeAll(Connection conn,Statement statement,ResultSet resultSet)
befor_dbutils.java
public class before_dbutils {
@Test
public void test1() throws SQLException{
//1.获取连接对象
Connection con=C3P0Utils.getConnection();
//2.获取statement对象
Statement stmt=con.createStatement();
//3.执行查询
ResultSet rs=stmt.executeQuery("select * from account");
//4.遍历
while(rs.next()){
System.out.println(rs.getString("name"));
}
//5.关闭
C3P0Utils.closeAll(con, stmt, rs);
}