changebookcontroller.java

学习jsp时做的一个书馆

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import library.DBConnection;


public class changeBookController extends Controller {
	 public void doPost (HttpServletRequest req,
				HttpServletResponse res) throws ServletException, IOException {
		HttpSession session = req.getSession();
		//req.setCharacterEncoding("GB2312"); 
		
		String id1 =  new String(req.getParameter("id1").getBytes("ISO-8859-1"),"GB2312");
		String findid =  new String(req.getParameter("findid").getBytes("ISO-8859-1"),"GB2312");
		String name = new String(req.getParameter("name").getBytes("ISO-8859-1"),"GB2312");
		String auther = new String(req.getParameter("auther").getBytes("ISO-8859-1"),"GB2312");
		String publisher =new String( req.getParameter("publisher").getBytes("ISO-8859-1"),"GB2312");
		String publishdata = new String(req.getParameter("publishdata").getBytes("ISO-8859-1"),"GB2312");
		String price = new String(req.getParameter("price").getBytes("ISO-8859-1"),"GB2312");
		String kind = new String(req.getParameter("kind").getBytes("ISO-8859-1"),"GB2312");
		String beizhu = new String(req.getParameter("beizhu").getBytes("ISO-8859-1"),"GB2312");
		
		session = req.getSession();
	
		boolean change = true;
		boolean change1 = true;
		
		if(name.equals("")&&auther.equals("")&&
				publisher.equals("")&&publishdata.equals("")&&price.equals("")&&
				kind.equals("")&&beizhu.equals("")){
			    change= false;
		}
		try {
		    if(change1 == false){	
			    res.sendRedirect("../admin/changebook.jsp?jieguo=failed2&id="+findid);
		    }else if(change==false){
		    	//res.sendRedirect("../test.jsp?jieguo="+"update reader set password = '"+newpasswd+"' where ReaderID='" +(String)session.getAttribute("readerno")+ "'");
		    	res.sendRedirect("../admin/changebook.jsp?jieguo=failed1&id="+findid);
		    }else{
			    String url ="jdbc:mysql://localhost/library?user=root&password=linux&useUnicode=true&characterEncoding=GB2312" ;
			    Connection conn= DriverManager.getConnection(url); 
			    Statement stmt=conn.createStatement();
			   
			    
			    String sql = "";
			    boolean rs = false;
			   
			    if(!name.equals("")){
			    	sql = "update books set name = '"+name+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!auther.equals("")){
			    	sql = "update books set auther = '"+auther+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!publisher.equals("")){
			    	sql = "update books set publisher = '"+publisher+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!publishdata.equals("")){
			    	sql = "update books set publdata = '"+publishdata+"' where isbn= '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!price.equals("")){
			    	sql = "update books set price = '"+price+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!kind.equals("")){
			    	sql = "update books set kind = '"+kind+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    if(!beizhu.equals("")){
			    	sql = "update books set beizhu = '"+beizhu+"' where isbn = '"+id1+"'";
			    	rs=stmt.execute(sql);
			    }
			    res.sendRedirect("../admin/searchbookresult.jsp?jieguo2=success&id1="+findid);	
			  // res.sendRedirect("../test.jsp?jieguo="+sql);	
		    }
		} catch (Exception e2) {
			sendErrorRedirect(req, res, e2);
		}
	    }
}