email.java

JSP开发的学生信息管理系统

package xuesheng;
import conn.DataBaseConnection;
import java.sql.Date;
import java.sql.*;
import java.util.*;
import java.io.*;
public class Email
{
	private Connection con=null;
	public Email()
	{
		this.con=DataBaseConnection.getConnection();
	}
	
	//发送对象
	 public String getSender(String studentId)
  {
  	Statement stmt = null;
    ResultSet rst = null;
    StringBuffer sBuf=new StringBuffer();
    try {
      stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
	  rst=stmt.executeQuery("select studentId,stuName from xuesheng where stuclass in(select stuclass from xuesheng where studentId='"+studentId+"')");
      while(rst.next()) { 
        String studentid= rst.getString("studentId").trim();
        String stuName= rst.getString("stuName");
        sBuf.append("<input type='checkbox' name='receiveStudentId' value='"+studentid+"'>"+stuName+"\n<br>");
        }
    }
    catch (SQLException ex) {
      return "";
    }
    finally
  	    	{
  	    		try{	
  	    		 if(stmt!=null){
  	    				stmt.close();
  	    			}	
	  	    		 if(con!=null){
	  	    		 	con.close();
	  	    		 }
  	    		}catch(Exception e)
  	    		{
  	    			e.printStackTrace();
  	    		}
  	    	
  	    	}
    return sBuf.toString();
  }
  
  
	//删除
	public void deleteEmail(String messageId)
	{
		PreparedStatement pstmt=null;
		try
		{
			pstmt=con.prepareStatement("delete from email where messageId=?"); 
			pstmt.setString(1,messageId);
			pstmt.execute();
		}
		catch(SQLException ex)
  	    	{
  	    		System.err.println(ex.getMessage());
  	    	}
  	    	finally
  	    	{
  	    		try{	
  	    		 if(pstmt!=null){
  	    				pstmt.close();
  	    			}	
	  	    		 if(con!=null){
	  	    		 	con.close();
	  	    		 }
  	    		}catch(Exception e)
  	    		{
  	    			e.printStackTrace();
  	    		}
  	    	
  	    	}	
	}


   //查询
	public ResultSet executeQuery(String sql)
  	{
  	     Statement stmt=null;
  	     ResultSet rst=null;
  	     try{
	  	      stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
	  	      rst=stmt.executeQuery(sql);
  	    	}catch(SQLException ex)
  	    	{
  	    		System.err.println(ex.getMessage());
  	    	}
  	    	return rst;
  	 }
  	 
  	 public void executeUpdate(String sql)
  	    {
  	    	Statement stmt=null;
  	    	try{
  	    		stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
  	    		stmt.executeUpdate(sql);
  	    	
  	    	}catch(SQLException ex)
  	    	{
  	    		System.err.println(ex.getMessage());
  	    	}
         }	
  	 //关闭
  	 public void close() 
        {
        	try{
        		if(con!=null){
        			con.close();
        		}
        		
        	}
        	catch(SQLException e)
        	{
        	   e.printStackTrace();	
        	}
        	
        }
     /*   
      public static void main(String[] args){
      	Email email=new Email();
      	String str=email.getSender("0368110051");
      	System.out.print(str);
      }  */
      
}