關於jsp連表查詢dao代碼的信息

本文目錄一覽：

• 1、連接數據庫進行查詢，怎樣把查詢到的結果在jsp中顯示，在servlet使用Dao中的方法是什麼？
• 2、jsp查詢數據庫代碼
• 3、jsp頁面調用dao方法問題
• 4、JSP連接數據庫的代碼
• 5、寫了一個Dao，連接數據庫進行查詢，怎樣把查詢到的結果在jsp中顯示，在servlet在使用Dao中的方法，

連接數據庫進行查詢，怎樣把查詢到的結果在jsp中顯示，在servlet使用Dao中的方法是什麼？

servlet配置到你的wed.xml中。

從數據庫中獲取到的數據放進響應中然後通過%=request.getAttribute(“bookId1”) %獲取對應的值當然僅僅有servlet和jsp頁面是不夠的還須要的是servlet配置到你的wed.xml中。這樣servlet才幹夠使用。

具體代碼如下：

package bookConnUtil;

import java.io.IOException;

import java.sql.SQLException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class selectBook extends HttpServlet {

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// TODO Auto-generated method stub

jsp查詢數據庫代碼

這種方法並不是很常用,只是頁面的相關操作，代碼太多,所以中間省略了部分%

Object userUID=session.getAttribute(“USERID”);

String uid=””;

if(userUID!=null)

{

uid=(String)userUID;

}

else

{ response.sendRedirect(“../Public/loseSession.jsp”);}

try

{

String today=DateUtils.getInstance().getToday();

String userIP=request.getRemoteAddr();

String sql=””;

String getPage=request.getParameter(“toPage”);

sql=cu.exchange(request.getParameter(“sql”)); if (sql==null||sql.equals(“”)){

String getDepId=””;

String getPoliticalPosition=””;

String getTechnicalPosition=””;

String getPoliticalLevel=””;

String getTechnicalLevel=””;

String getDegreeCode=””;

String getGrade=””;

String getLongevity=””;String getAllowance=””;

long depId=0;

long degreeCode=0;

long politicalPosition=0;

long technicalPosition=0;

long politicalLevel=0;

long technicalLevel=0;

long grade=0;

long longevity=0;

long allowance=0;

String[] postID=null;

String post=””;

String userID=””;

String userName=””;

String address=””;

getDepId=request.getParameter(“depId”);

depId=Long.parseLong(getDepId.trim());getDegreeCode=request.getParameter(“degreeCode”);

if (getDegreeCode!=null) {

degreeCode=Long.parseLong(getDegreeCode.trim());

}

getPoliticalPosition=request.getParameter(“politicalPosition”);

if (getPoliticalPosition!=null) {

politicalPosition=Long.parseLong(getPoliticalPosition.trim());

}

post=request.getParameter(“post”);

if(post!=nullpost.trim().equals(“1”))

postID=request.getParameterValues(“dyourlocation”);

getTechnicalPosition=request.getParameter(“technicalPosition”);if (getTechnicalPosition!=null) {

technicalPosition=Long.parseLong(getTechnicalPosition.trim());

}

getPoliticalLevel=request.getParameter(“politicalLevel”);if (getPoliticalLevel!=null) {politicalLevel=Long.parseLong(getPoliticalLevel.trim());

}getTechnicalLevel=request.getParameter(“technicalLevel”);if (getTechnicalLevel!=null) {

technicalLevel=Long.parseLong(getTechnicalLevel.trim());

}getGrade=request.getParameter(“grade”);if (getGrade!=null) {

grade=Long.parseLong(getGrade.trim());

}getLongevity=request.getParameter(“longevity”);if (getLongevity!=null) {

longevity=Long.parseLong(getLongevity.trim());

}getAllowance=request.getParameter(“allowance”);

if (getAllowance!=null) {

allowance=Long.parseLong(getAllowance.trim());

}

userID=ParamUtils.getParameter(request,”userID”);//用戶代碼

userName=ParamUtils.getParameter(request,”userName”);

//用戶名稱

address=ParamUtils.getParameter(request,”address”);

//得到要轉入的頁面sql=”select org_user.* from org_user,org_detail where org_user.user_id=org_detail.user_id”;

if (depId!=0)

{

sql=sql+” and org_user.department_id=”+depId+””;

}if (userID!=nulluserID!=””){

sql=sql+” and org_user.user_id='”+userID+”‘”;

}

if (userName!=nulluserName!=””)

{

sql=sql+” and org_user.name like ‘%”+userName+”%'”;

}if (address!=nulladdress!=””)

{

sql=sql+” and org_user.address like ‘%”+address+”%'”;

}

if(post!=null!post.trim().equals(“0”))

{

sql=sql+” and org_detail.post in (“;

for(int i=0;ipostID.length;i++)

{

sql=sql+postID[i];

if(i!=(postID.length-1))

sql=sql+”,”;

}

sql=sql+”)”;

}

if (degreeCode!=0)

{

sql=sql+” and org_detail.degree=”+degreeCode+””;

}

if (politicalPosition!=0)

{

sql=sql+” and org_detail.politicalPosition=”+politicalPosition+””;

}

if (technicalPosition!=0)

{

sql=sql+” and org_detail.technicalPosition=”+technicalPosition+””;

}

if (technicalPosition!=0)

{

sql=sql+” and org_detail.politicalLevel=”+politicalLevel+””;

}

if (grade!=0)

{

sql=sql+” and org_detail.grade=”+grade+””;

}

if (longevity!=0)

{

sql=sql+” and org_detail.longevity=”+longevity+””;

}

if(getAllowance!=null)

{

if (allowance==0||allowance==1)

{

sql=sql+” and org_detail.allowance=”+allowance+””;

}

}

}

User[] userList =null;

userList=ur.complexSearch(sql);

log.addLog(1,1,1,uid,userIP,uid+”於(“+today+”)查詢員工”);int cnt=userList.length;//總記錄數

int pageSize=10;//每頁顯示記錄數

int curPage=1;//當前頁

int cntPage;//總頁數

int m=1; if (cnt0)

{

if (cnt%pageSize==0)

cntPage=cnt/pageSize;

else

cntPage=cnt/pageSize+1;

}

else

cntPage=0; if (getPage==null)

{

getPage=”1″;

curPage=1;

}

else

curPage=Integer.parseInt(getPage.trim());

%form name=”thisform” action=”userSearchDel.jsp” method=”post”

table bgColor=”#FFFFFF” border=”1″ borderColorDark=”#ffffff” borderColorLight=”#c0c0c0″ cellSpacing=”0″ width=”95%” cellpadding=”4″

tr height=”25″ align=”center” bgcolor=”#959595″

td 　/td

tdfont color=”#FFFFFF”姓名/font/td

tdfont color=”#FFFFFF”性別/font/td

td font color=”#FFFFFF”所在部門/font/td

td font color=”#FFFFFF”辦公地址/font/td

tdfont color=”#FFFFFF”聯繫電話/font/td

/tr

%

int u=1;

for(int i=0;icnt;i++)

{

//顯示記錄的起始位置

int j=(curPage-1)*pageSize;

//顯示記錄的末位置

int k=curPage*pageSize;

//只顯示page_size條數據

if(mjm=k)

{

String userId=userList[i].getUserID();

String gender=userList[i].getGender();

String name=userList[i].getName();

String tel=userList[i].getTel();

String useAddress=userList[i].getAddress();

long dep_id=userList[i].getDepID();

String dname=dep.getName(userList[i].getDepID());

if(tel==null||tel.equals(“null”))

tel=””;

if(useAddress==null||useAddress.equals(“null”))

useAddress=””;

//判斷沒一行該輸出的顏色

if((u%2)==0)

{

out.println(“tr bgcolor=#D7D7D7 onMouseOver=this.style.backgroundColor=’#fcd4d7′; onMouseOut=if(selectedItem!=this.id){this.style.backgroundColor=’#D7D7D7′;}”);

}

else

{

out.println(“tr onMouseOver=this.style.backgroundColor=’#fcd4d7′; onMouseOut=if(selectedItem!=this.id){this.style.backgroundColor=’#FFFFFF’;}”);

}

u++;

%

td align=centerinput type=”checkbox” name=”checkbox” id=”CHK_+%=userId%” value=”%=userId%”/td

td align=center

%

long departmentID=ur.getDepID(uid);

if(up.haveRight(uid,”USER_COMPLEXQUERY”)==true)

{

%

a href=”userAnalyze.jsp?userId=%=userId%dep_id=%=dep_id%toPage=%=curPage%”font color=”#330099″

%

}

else if(up.haveRight(uid,”DEPARTMENT_PLATFORM”)==truedep_id==departmentID)

{

%

a href=”userAnalyze.jsp?userId=%=userId%dep_id=%=dep_id%toPage=%=curPage%”font color=”#330099″

%

}

%

%=name%/font/a/td

%

if(gender.trim().equals(“0”))

out.println(“td align=center男/td”);

else

out.println(“td align=center女/td”);

%

td align=centera href=”depintro.jsp?id=%=dep_id%toPage=%=curPage%”font color=”#330099″%=dname%/font/a/td

td align=center %=useAddress%/td

td align=center %=tel%/td

/tr

%

}//end if m++;

}//end for

%

input type=hidden name=”sql” value=”%=sql%”

input type=hidden name=”page” value=”%=curPage%”

/table

/form

form name=pageform action=”searchAction.jsp” method=”post”

table border=”0″ width=”95%”

tr

td align=”center”第%=curPage%頁/共%=cntPage%頁/td

td align=”left”

img name=”firstpage” src=”../Image/btn_firstpage.gif” style=”cursor:hand” onclick=”pageClick(1)” %=curPage1?” “:”disabled”%

img name=”prepage” src=”../Image/btn_prepage.gif” style=”cursor:hand” onclick=”pageClick(%=curPage-1%)” %=curPage1?” “:”disabled”%

img name=”nextpage” src=”../Image/btn_nextpage.gif” style=”cursor:hand” onclick=”pageClick(%=curPage+1%)” %=curPagecntPage?” “:”disabled”%

img name=”lastpage” src=”../Image/btn_lastpage.gif” style=”cursor:hand” onclick=”pageClick(%=cntPage%)” %=curPagecntPage?” “:”disabled”%

/td

td align=left width=55%

到第input type=”text” name=”goPage” size=”4″頁

img border=”0″ src=”../Image/icon_search.gif” style=”cursor:hand” onclick=”aPage()”

/td

/trtr

td colspan=”3″ valign=”middle” width=”23%” align=”right”

%

if(up.haveRight(uid,”USER_MANAGE”)==true)

{

%

img border=”0″ src=”../Image/btn_delete.gif” style=”cursor:hand” onclick=”delUser()”

%}%

img border=”0″ src=”../Image/btn_return.gif” style=”cursor:hand” onclick=”back()”

/td

input type=hidden name=”sql” value=”%=sql%”

input type=hidden name=”toPage”

/td

/tr

/table

/form

br

br

/td

/tr

/table

/td

/tr

/table

%

}//end else

}//end try

catch(Exception e)

{

out.println(e.getMessage());

}

%

/td

/tr

/table

jsp頁面調用dao方法問題

jsp沒辦法直接調用到DAO層的。

解釋：

因為根據三層結構，jsp屬於view層，之後是controler層，最好才是model層。或者是jsp為action，之後是server層，之後是dao層。不管怎麼算，都沒辦法直接調用的。

備註：

上面的只是代碼規範，但是提問非要這麼乾的話，也沒問題，直接在java類中action方法下，調用Dao方法即可。

JSP連接數據庫的代碼

Class.forName(“com.mysql.jdbc.Driver”);

Connection conn=DriverManager.getConnection(“jdbc:mysql://”+host+”/”+dbname,username,password);

Statement Stmt=conn.createStatement();

ResultSet rs=Stmt.executeQuery(sql);

這是基本的數據庫操作方法

大概流程就是加載驅動類，創建連接，執行數據庫操作，關閉

寫了一個Dao，連接數據庫進行查詢，怎樣把查詢到的結果在jsp中顯示，在servlet在使用Dao中的方法，

jsp 直接寫代碼好了 記得把dao倒進來就行了

%@page import=”entity.*” %

%

UserDao dao =…..

ListUser users = dao.getUser…….

for( int i =0 ;iusers.size();i++){

User user = users.get(i);

%