mysq连接 mysql-connector-java-5.1.34.jar

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import org.omg.CORBA.PRIVATE_MEMBER;

/**
* @author 閮戞按娲�
* SQL SERVER 2005杩炴帴
* 绔�彛榛樿�鏄�細1433 杩欓噷鏄�434
*
* 鍦ㄥ唴瀛樹腑锛屽彧闇��鍔犺浇涓��鏁版嵁搴撻┍鍔ㄥ嵆鍙�紝鎵�互搴旇�鏀惧埌static浠ｇ爜蹇�腑 (浼樺寲鎬ц兘)
*/
public class JdbcUtil {

private static String url = "jdbc:mysql://localhost:3306/mysql";
private static String userName = "root";
private static String password ="root";
private static String driverName = "com.mysql.jdbc.Driver";

//1.鍔犺浇鏁版嵁搴撻┍鍔�
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO: handle exception
e.printStackTrace();
System.out.println("鏁版嵁搴撳姞杞介┍鍔ㄥけ璐�");
}
}

//2.寤虹珛杩炴帴
public static Connection getConnection(){
Connection connection = null;
try {
connection = DriverManager.getConnection(url, userName, password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return connection;
}
//3.鐢虫槑sql鎵ц�鍣�

//4.鎵ц�SQL 鎿嶄綔鏁版嵁

// 5銆佸叧闂�祫婧�
public static void free(ResultSet resultSet,Statement statement,PreparedStatement preparedStatement,Connection connection){
try{
if (resultSet!=null) {
resultSet.close();
}
}catch (SQLException e) {
e.printStackTrace();
}finally{
try {
if(statement!=null){
statement.close();
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
if (preparedStatement!=null) {
preparedStatement.close();
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
if (connection!=null) {
connection.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
//query
// public static ArrayList<Object> query(String sql,String colum){//搴旇�鐢ㄥ弽灏�
//
// Connection connection = null;
// ResultSet resultSet = null;
// PreparedStatement preparedStatement =null;
//
// try{
// connection = getConnection();
// //SQL鎵ц�鍣�
// preparedStatement = connection.prepareStatement(sql);
// resultSet =preparedStatement.executeQuery();
// while (resultSet.next()) {
// resultSet.getString(colum);
// }
// }catch(Exception e){
// e.printStackTrace();
// }finally{
//
// }
// return null;
// }

//query 瀛楁�
public static String query(String sql,String colum){//搴旇�鐢ㄥ弽灏�

Connection connection = null;
ResultSet resultSet = null;
PreparedStatement preparedStatement =null;
String str ="";

try{
connection = getConnection();
//SQL鎵ц�鍣�
preparedStatement = connection.prepareStatement(sql);
resultSet =preparedStatement.executeQuery();
while (resultSet.next()) {
str = resultSet.getString(colum);
}
}catch(Exception e){
e.printStackTrace();
}finally{

}
return str;
}

public static void main(String[] args) {
String sql =" select * from demo r where r.id=1";
String colum = "name";
System.out.println(query(sql,colum));
}
}