b064f4f7070a001c1ae389e389b64382

这是一个小程序 网上书店用的 我们学生做的一个小实验

import bean.*;
import java.util.*;
import java.io.*;
import java.net.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 * Class <b>SearchController</b> contains 
 * the servlet controller functionality for processing
 * user search requests.
 * 
 *
 * @author ProjectGroup	
 * @version 1.0.0
 */
public class SearchController extends Controller {

    /**
     * SearchController doPost method.  This is can be called
     * by <b>Controller</b> superclass' doGet() method.
     * @param req HttpServletRequest servlet request object
     * @param res HttpServletResponse servlet response object
     * @throws ServletException
     * @throws IOException
     */
    public void doPost (HttpServletRequest req, HttpServletResponse res)
	throws ServletException, IOException {
	
	// Get the search parameters.
	String action = req.getParameter("action");
	String pterms = req.getParameter("str");
	HttpSession session=req.getSession();
	// Redirect the user back to the index page if no terms are selected
	if (pterms.equals("")) {
	    res.sendRedirect("/e-commerce/index.jsp");
	} else {
	    // Get the searchby parameter;
	    String searchby = req.getParameter("searchby");		
	    
	    // Build the sql statement based on what is to be searched on (author or title).
	    String sql = "select * from booktitle where ";
	    
	    if (searchby.equals("author")) {
		sql += "B_Author like '%" + pterms + "%'";
	    } 
	    if (searchby.equals("title")) {
	    sql +="B_Title like '%"+pterms+"%'";
	    }
	    else if(searchby.equals("Catalogue")){
	    sql +="B_ISBN=any(select isbn from bt_belong_categ where Categ_num=any(select Categ_num from Categories where Categ_name likes '%"+pterms+"%'))";
	    }
	    
	    // The results of the search are to be stored in a BookTitleSet object.
	    BookTitleSet results = new BookTitleSet();
	    
	    // Execute the search and fill the BookTitleSet with the results.
	    try {
		ResultSet r = null;
		
		// Get an instance of the singleton DBWrapper object.
		DBWrapper db = DBWrapper.Instance();
		
		// Run the query.
		r = db.runQuery( sql );
		
		// Fill the BookTitleSet with BookTitles.
		while (r.next()) {
		    BookTitle tempTitle =  new BookTitle( r.getString( "B_Title" ), r.getString( "B_Author" ),
							  r.getString( "B_ISBN" ), r.getString( "B_Edition" ),r.getString("pub_num"),r.getString("B_DatePublished"), 
							  r.getDouble( "B_Price" ), r.getDouble( "B_disount" ),r.getString("B_Description"),r.getInt("qtyinstock"),
							  r.getString( "Cata_num" ));
		    results.addBookTitle( tempTitle );
		    
		}
	    } catch ( Exception e ) {
		// Send this exception to the standard error page.
		sendErrorRedirect(req, res, e);
	    }
	    
	    /**
	     * Redirect to the search.jsp page to display the search results.
	     * The search results are stored in the HttpServletRequest's
	     * session.
	     */
	    try {
		req.getSession().setAttribute("results", results);
		//res.sendRedirect("/e-commerce/search.jsp");
	    } catch( Exception e ){
		sendErrorRedirect(req, res, e);
	    }
	    return;
	}
    }
}