service.java

DWR实例开发 ajax开发 完整实例 带数据库

package helloWorld;
import java.sql.*;

public class Service {
	public Service()
	{
		try
		{
			Class.forName("com.mysql.jdbc.Driver");
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
	}
	
	public Connection getConnection()
	{
		Connection conn=null;
		try
		{
			conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test?user=root&password=sa");
			return conn;
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		return null;
	}
	public String sayHello(String aaa) {
		Connection conn=getConnection();
		PreparedStatement pstat=null;
		ResultSet rset=null;
		int cnt=0;
		try
		{
			String sql="SELECT * from popo where name=?";
			pstat=conn.prepareStatement(sql,ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
			pstat.setString(1, aaa);
			rset=pstat.executeQuery();
			rset.last();
			cnt=rset.getRow();
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		finally
		{
			try
			{
				if(rset!=null)rset.close();
				if(pstat!=null)pstat.close();
				if(conn!=null)conn.close();
			}
			catch(Exception e)
			{
				e.printStackTrace();
			}
		}
		if(cnt==1)
			return "您的用户名已被注册";
		return "您的用户名可以注册";
		
	}
}