jdbc连接数据库的优化和防止注入

package dao;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;


import org.junit.Test;


public class JDBCDAO {
static Connection conn =null;
@Test
private static Connection getConnection(){

try{
Class.forName("com.mysql.jdbc.Driver");


}catch (Exception e) {
e.printStackTrace();

// TODO: handle exception
}
try{
String user="root";
String password="";
String url="jdbc:mysql://localhost:3306/test?";
conn=DriverManager.getConnection(url,user,password);

}catch (Exception e) {
e.printStackTrace();
// TODO: handle exception
}
return conn;
}
public Statement getStatement() throws SQLException{
return getConnection().createStatement();

}
public PreparedStatement getPrepareStatment(String sql) throws SQLException{
return getConnection().prepareStatement(sql);

}


}