jdbc分页操作

UserInfoDao

private int pageSize = 10;// 每页记录数

//  获取总条数/总页数
public int count() throws SQLException{
int totalPages = 0;//总页数totalPages
Connection connection = manager.getConnection();
try{
String sql="select count(1) from "+TABLE_NAME;
PreparedStatement queryPreStatement=connection.prepareStatement(sql);
ResultSet rs=queryPreStatement.executeQuery();
if(rs.next()){
int rowCount = rs.getInt(1);
totalPages=rowCount%pageSize==0?rowCount/pageSize:rowCount/pageSize+1;
}
}finally{
if(connection!=null)connection.close();
}
return totalPages;
}

mysql分页查询语句：select o.* from (select * from wyuser) o limit firstIndex,pageSize

oracle分页查询语句1：select * from(select a.*,ROWNUM rn from(select * from wyuser order by ID asc) a where ROWNUM<=(firstIndex+pageSize)) where rn>firstIndex

oracle分页查询语句2：select * from(select * from(select t.*,row_number() over(order by orderColumn) as rownumber from(select * from wyuser) t) p where p.rownumber>firstIndex) where rownum<=pageSize

//  sql语句分页查询 count=当前页
public List<UserInfo> page(int count) throws SQLException{
List<UserInfo> userInfoList = new ArrayList<UserInfo>();
Connection connection = manager.getConnection();
try {
//String sql="select top "+pageSize+" * from "+TABLE_NAME+" where id>(select max (id) from (select top (("+count+"-1)*"+pageSize+") id from "+TABLE_NAME+" order by id) as T) order by id";
String sql1="select top "+pageSize+" * from "+TABLE_NAME+" where UserID not in(select top (("+count+"-1)*"+pageSize+") UserID from "+TABLE_NAME+" order by UserID) order by UserID";
Statement st = connection.createStatement();
ResultSet rs = st.executeQuery(sql1);
while (rs.next()) {
UserInfo userInfo = new UserInfo();
userInfo.setUserID(rs.getInt("UserID"));
userInfo.setUserName(rs.getString("UserName"));
userInfo.setLastLoginDate(rs.getDate("LastLoginDate"));
userInfo.setPoints(rs.getBigDecimal("Points"));
userInfoList.add(userInfo);
}
rs.close();
st.close();
} finally {
if (connection != null) {
connection.close();
}
}
return userInfoList;
}

//  修改积分
public int updatePoint(UserInfo userInfo) throws SQLException{
Connection connection = manager.getConnection();
try{
String sql="update "+TABLE_NAME+" set Points=? where UserID=?";
PreparedStatement updatePreStatement=connection.prepareStatement(sql);
updatePreStatement.setBigDecimal(1, userInfo.getPoints());
updatePreStatement.setInt(2, userInfo.getUserID());
return updatePreStatement.executeUpdate();
}finally{
if(updatePreStatement!=null)updatePreStatement.close();
if(connection!=null)connection.close();
}
}

//  根据用户名查找
public List<UserInfo> filterUser(String userName) throws SQLException{
List<UserInfo> userInfoList=new ArrayList<UserInfo>();;
Connection connection = manager.getConnection();
try{
String sql="select * from "+TABLE_NAME+" where UserName='"+userName+"'";
Statement st = connection.createStatement();
ResultSet rs = st.executeQuery(sql);
//List<Map<String, Object>> result=this.query(sql);
while (rs.next()) {

3ff7
UserInfo userInfo = new UserInfo();
userInfo.setUserID(rs.getInt("UserID"));
userInfo.setUserName(rs.getString("UserName"));
userInfo.setLastLoginDate(rs.getDate("LastLoginDate"));
userInfo.setPoints(rs.getBigDecimal("Points"));
userInfoList.add(userInfo);
}
//      if(result!=null&&result.size()>0){
//          Map<String, Object> row=result.get(0);
//          userInfo.setUserID((Integer)row.get("UserID"));
//          userInfo.setUserName((String)row.get("UserName"));
//          userInfo.setLastLoginDate((Date)row.get("LastLoginDate"));
//          userInfo.setPoints((BigDecimal)row.get("Points"));
//      }
return userInfoList;
}finally{
if(connection!=null)connection.close();
}
}

//  根据id获取
public UserInfo get(int id) throws SQLException{
UserInfo userInfo=null;
Connection connection = manager.getConnection();
try{
String sql="select * from "+TABLE_NAME+" where UserID=?";
PreparedStatement queryPreStatement=connection.prepareStatement(sql);
queryPreStatement.setInt(1, id);
ResultSet rs=null;
rs=queryPreStatement.executeQuery();
userInfo=new UserInfo();
while(rs.next()){
userInfo.setUserID(rs.getInt("UserID"));
userInfo.setUserName(rs.getString("UserName"));
userInfo.setLastLoginDate(rs.getDate("LastLoginDate"));
userInfo.setPoints(rs.getBigDecimal("Points"));
break;
}
return userInfo;
}finally{
if(connection!=null)connection.close();
}
}

UserInfoService

private UserInfoDao userInfoDao=new UserInfoDao();
//  更新 目前只更新积分
public int updatePoint(UserInfo userInfo) throws SQLException{
return userInfoDao.updatePoint(userInfo);
}
//  根据用户名查找
public List<UserInfo> filterUser(String userName) throws SQLException{
return userInfoDao.filterUser(userName);
}
//  根据id获取
public UserInfo get(int id) throws SQLException{
return userInfoDao.get(id);
}
//  获取总条数
public int count() throws SQLException{
return userInfoDao.count();
}
/**
* sql语句分页查询
* @param count 当前页码
* @return
* @throws SQLException
*/
public List<UserInfo> page(int count) throws SQLException{
return userInfoDao.page(count);
}

userInfoServlet

/**
* @see HttpServlet#HttpServlet()
*/
public UserInfoServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String cmd=request.getParameter("cmd");
response.setCharacterEncoding("utf-8");
if(cmd==null)return;
else if (cmd.equals("page")){
this.page(request,response);
}
else if (cmd.equals("filterUser")){
this.filterUser(request,response);
}
else if (cmd.equals("updatePoint")){
this.updatePoint(request,response);
}
else if (cmd.equals("save")){
this.save(request,response);
}
//  else if(cmd.equals("new")) {
//      request.setAttribute("action", "add");
//      request.getRequestDispatcher("/user/form.jsp").forward(request, response);
//      return;
//  }else if(cmd.equals("add")) {
//      Charset.defaultCharset();
//      request.setCharacterEncoding("UTF-8");
//      this.add(request, response);
//  }
}

//  更新 目前只更新积分
private void updatePoint(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id=request.getParameter("id");
if(id==null){
request.setAttribute(Constants.PAGE_MESSAGE_KEY, "参数不能为空。");
}else{
UserInfoService userInfoService=new UserInfoService();
try {
UserInfo userInfo=userInfoService.get(Integer.parseInt(id));
request.setAttribute("action", "save");
request.setAttribute("userInfo", userInfo);
request.getRequestDispatcher("/userInfo/form.jsp").forward(request, response);
return;
} catch (SQLException e) {
e.printStackTrace();
request.setAttribute(Constants.PAGE_MESSAGE_KEY, "数据读取错误。");
}
}
response.sendRedirect(request.getContextPath()+"/UserInfoServlet?cmd=page&count=1");
}

//  sql语句分页查询
private void page(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
UserInfoService userInfoService=new UserInfoService();
try {
int count = Integer.parseInt(request.getParameter("count"));
List<UserInfo> userInfos=userInfoService.page(count);
request.setAttribute("datas", userInfos);
request.setAttribute("currentPage", count);
request.setAttribute("totalPages", userInfoService.count());
} catch (SQLException e) {
e.printStackTrace();
request.setAttribute(Constants.PAGE_MESSAGE_KEY, "数据加载失败。");
}
request.getRequestDispatcher("/userInfo/list.jsp").forward(request, response);
}

//  根据用户名查找
private void filterUser(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
UserInfoService userInfoService=new UserInfoService();
try {
String filter_text = request.getParameter("filter_text");
List<UserInfo> userFilter=userInfoService.filterUser(filter_text);
request.setAttribute("datas", userFilter);
} catch (SQLException e) {
e.printStackTrace();
request.setAttribute(Constants.PAGE_MESSAGE_KEY, "数据加载失败。");
}
request.getRequestDispatcher("/userInfo/list.jsp").forward(request, response);
}

//  保存
private void save(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id=request.getParameter("id");
String points = request.getParameter("points");
BigDecimal bigDecimal=new BigDecimal(points);
UserInfoService userInfoService=new UserInfoService();
try {
UserInfo userInfo=userInfoService.get(Integer.parseInt(id));
userInfo.setPoints(bigDecimal);
userInfoService.updatePoint(userInfo);
} catch (SQLException e) {
request.setAttribute(Constants.PAGE_MESSAGE_KEY, "用户添加失败。");
}
response.sendRedirect(request.getContextPath()+"/UserInfoServlet?cmd=page&count=1");
}

list.jsp

<body>
<div class="row">
<div class="col-xs-12">
<div class="table-responsive">
<div id="sample-table-2_wrapper" class="dataTables_wrapper" role="grid">
<div class="row">
<div class="col-sm-4">
<form id="inputForm" action="${ctx}/UserInfoServlet?cmd=filterUser" method="post" class="form-horizontal">
<div class="input-group">
<input class="form-control" type="text" id="filter_text" name="filter_text">
<span class="input-group-btn">
<button  id="sel_appointment_button" class="btn btn-sm btn-default" type="submit">
<i class="icon-search bigger-110"></i>用户名查找
</button>
</span>
</div>
</form>
</div>
<div class="col-sm-1">
<div id="sample-table-2_info" class="dataTables_info">
<a class="btn btn-primary" href="${ctx}/UserInfoServlet?cmd=new"><i class="icon-plus"></i>添加</a>
</div>
</div>
<div class="col-sm-1">
<div id="sample-table-2_info" class="dataTables_info">
<a class="btn btn-primary" href="${ctx}/UserInfoServlet?cmd=emptyPoints"><i class="icon-plus"></i>清空积分CompanyID=5000001</a>
</div>
</div>
</div>
<table id="contentTable" class="table table-striped table-bordered table-condensed">
<thead>
<tr>
<th>用户ID</th>
<th>用户名称</th>
<th>最后登录时间</th>
<th width="280">操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${datas}" var="item">
<tr>
<td>${item.userID}</td>
<td>${item.userName}</td>
<td>${item.lastLoginDate}</td>
<td>
<a id="a_updatePoint" class="btn btn-xs btn-info" href="${ctx}/UserInfoServlet?cmd=updatePoint&id=${item.userID}">
修改积分
</a>
<%-- <a id="a_delete" class="btn btn-xs btn-danger" href="${ctx}/pc/user?cmd=delete&id=${item.userID}">
删除
</a> --%>
</td>
</tr>
</c:forEach>
</tbody>
</table>
<div class="row">
<div class="col-sm-12">
<a href="${ctx}/UserInfoServlet?cmd=page&count=1">首页</a>
<c:if test="${currentPage>1}">
<a href="${ctx}/UserInfoServlet?cmd=page&count=${currentPage-1}">上一页</a>
</c:if>
第${currentPage}页
<c:if test="${currentPage<totalPages}">
<a href="${ctx}/UserInfoServlet?cmd=page&count=${currentPage+1}">下一页</a>
</c:if>
<a href="${ctx}/UserInfoServlet?cmd=page&count=${totalPages}">尾页</a>
</div>
</div>
</div>
</div>
</div>
</div>
</body>

form.jsp

<body>
<div class="row">
<div class="col-xs-12">
<form id="inputForm" action="${ctx}/UserInfoServlet?cmd=${action}" method="post" class="form-horizontal" enctype="application/x-www-form-urlencoded">
<input type="hidden" name="id" value="${userInfo.userID}" />
<fieldset>
<div class="form-group">
<label for="name" class="col-sm-3 control-label no-padding-right">积分:</label>
<div class="col-sm-9">
<input  type="text" id="points" name="points"
value="${userInfo.points}" />
</div>
</div>
<div class="clearfix form-actions">
<div class="col-md-offset-3 col-md-9">
<button id="submit_btn" class="btn btn-danger" type="submit">
<i class="icon-ok bigger-110"></i> 提交
</button>
<button id="cancel_btn" class="btn btn-info" type="button"
οnclick="history.back()">
<i class="icon-reply icon-only"></i> 返回
</button>
</div>
</div>
</fieldset>
</form>
</div>
</div>
</body>