java 学习之连接 Mysql 首先导入 mysql-connector-java-5.1.10-bin.ja 下载地址： http://download.csdn.net/detail/u014112584/7359185 鼠标放在项目上，右击选择Properties-----Java Build Path ------Add External JARS 测试代码： import java.sql.Connec
java 学习之连接 Mysql首先导入mysql-connector-java-5.1.10-bin.ja
下载地址：http://download.csdn.net/detail/u014112584/7359185
鼠标放在项目上，右击选择Properties----->Java Build Path ------>Add External JARS
测试代码：
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.mysql.jdbc.PreparedStatement;
import com.mysql.jdbc.Statement;
public class MysqlTest {
static String drivername="com.mysql.jdbc.Driver";
static String url="jdbc:mysql://localhost:3306/expression";//指向数据源
static String username="root";
static String password="";
static java.sql.Statement stmt=null;
static ResultSet re=null;
static Connection conn=null;
static PreparedStatement pstm=null;
/*
* 构造函数进行初始化
*/
public MysqlTest(){
try{
Class.forName(drivername);//将驱动加载到运行环境中，加载的时候，驱动会自动向DriverManager完成注册
System.out.println("创建驱动成功");
}catch(ClassNotFoundException e){
e.printStackTrace();
}
}
/*
* 获取连接
*/
public static Connection getConnection(){
conn=null;
try{
conn=(Connection)DriverManager.getConnection(url, username, password);//有了驱动和连接地址后，需要使用DriverManager来获取连接
System.out.println("连接数据库成功！");
}catch(SQLException e){
e.printStackTrace();
}
return conn;
}
/**
* 关闭连接
* @param args
*/
public static void free(ResultSet rs,Connection conn,java.sql.Statement stmt2){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("关闭ResultSet失败！");
e.printStackTrace();
}finally{
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("关闭Connection失败！");
e.printStackTrace();
}finally{
if(stmt2!=null){
try {
stmt2.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("关闭Statement失败！");
e.printStackTrace();
}
}
}
}
}
}
}
public static void main(String[]args){
MysqlTest.getConnection();
try {
stmt=conn.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
re=stmt.executeQuery("select * from data");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int i=1;
try {
while(re.next()){
System.out.println(i++);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
free(re,conn,stmt);
System.out.println("OK");
}
}
