分页使用
1。
<mytag:pagingDisplay />
2。
<tag>
<name>pagingDisplay</name>
<tagclass>nm.tag.DisplayTag</tagclass>
<bodycontent>empty</bodycontent>
<info> A demo </info>
</tag>
3。
package nm.tag;
import java.util.Vector;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
import nm.Notice;
public final class DisplayTag extends TagSupport {
private static final long serialVersionUID = 1L;
public int doEndTag() throws JspException {
JspWriter out = pageContext.getOut();
HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
String strPage = request.getParameter("page");
int page;
if (strPage == null || strPage.equals(""))
page = 1;
else {
page = Integer.parseInt(strPage);
}
try {
int pageSize = 2; //设置每页有几条数据
Vector noticeVector = Notice.search(pageSize, page);
out.println("<table width=/"80%/" border=/"1/" align=/"center/"");
out.println("<tr align=/"center/" bgcolor=/"#CC99CC/">");
out.println("<th width=/"35%/">标题</th>");
out.println("<th width=/"35%/">内容</th>");
out.println("<th width=/"15%/">修改</th>");
out.println("<th width=/"15%/">删除</th>");
out.println("</tr>");
String title = null;
String content = null;
Notice bean = null;
if(noticeVector!=null&¬iceVector.size()!=0){
for (int i = 0; i < noticeVector.size(); i++) {
bean = (Notice) noticeVector.elementAt(i);
title = bean.getTitle();
//title = new String(title.getBytes("ISO-8859-1"), "GB2312");
content = bean.getContent();
// content = new String(content.getBytes("ISO-8859-1"), "GB2312");
out.println("<tr align=/"center/" bgcolor=/"#CCFF99/">");
out.println("<td height=/"80/">" + title + "</td>");
out.println("<td>" + content + "</td>");
out.println("<td>"
+ "<a href=/"checkpower.do?functiontype=noticeedit&id="
+ bean.getID() + "/">Edit</a> " + "</td>");
out
.println("<td>"
+ "<a href=/"checkpower.do?functiontype=noticedelete&id="
+ bean.getID() + "/">Delete</a> " + "</td>");
out.println("</tr>");
}
out.println("<tr align=/"right/" bgcolor=/"#CCFF66/">");
out.println("<th colspan=/"4/">");
if(page!=-1){
out.println("<a href=/"noticelistjsp.do?page=-1/">首页</a> ");
}
out.println("<a href=/"noticelistjsp.do?page=-2/">上一页</a> ");
out.println("<a href=/"noticelistjsp.do?page=-3/">下一页</a> ");
if(page!=-4){
out.println("<a href=/"noticelistjsp.do?page=-4/">尾页</a></th>");
}
out.println("</tr>");
}
out.println("</table>");
} catch (Exception ex) {
throw new JspTagException("IOException:" + ex.toString());
}
return super.doEndTag();
}
}
4。
package nm;
import java.sql.ResultSet;
import java.sql.SQLException;
public class Pageable {
private int pageSize;
private int totalRows;
private int totalPages;
private static int currentPage;
private int rowsCount;
public Pageable(ResultSet rs) {
try {
rs.last();
} catch (SQLException e) {
e.printStackTrace();
}
try {
this.setTotalRows(rs.getRow());
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
rs.beforeFirst();
} catch (SQLException e2) {
e2.printStackTrace();
}
}
public void setPageSize(int pageSize) {
if (pageSize > 0) {
this.pageSize = pageSize;
} else {
this.pageSize = 1;
}
this.setTotalPages();
}
public void gotoPage(int page) {
switch (page) {
case -1:
this.setCurrentPage(1);
break;
case -2:
if (this.getCurrentPage() != 1) {
this.setCurrentPage(this.getCurrentPage() - 1);
} else {
this.setCurrentPage(1);
}
break;
case -3:
if (this.getCurrentPage() != this.getTotalPages()) {
this.setCurrentPage(this.getCurrentPage() + 1);
} else {
this.setCurrentPage(this.getTotalPages());
}
break;
case -4:
this.setCurrentPage(this.getTotalPages());
break;
default:
this.setCurrentPage(page);
}
}
public void setCurrentPage(int page) {
if (page <= 0)
Pageable.currentPage = 1;
if (page > this.getTotalPages())
Pageable.currentPage = this.getTotalPages();
else
Pageable.currentPage = page;
this.setRowsCount((Pageable.currentPage - 1) * this.getPageSize() + 1);
}
public int getCurrentPageRowsCount() {
if (this.getPageSize() == 0)
return this.getTotalRows();
if (this.getTotalRows() == 0)
return 0;
if (this.getCurrentPage() != this.getTotalPages())
return this.getPageSize();
return this.getTotalRows() - (this.getTotalPages() - 1)
* this.getPageSize();
}
public int getPageSize() {
return this.pageSize;
}
public int getTotalRows() {
return totalRows;
}
public void setTotalRows(int totalRows) {
this.totalRows = totalRows;
}
public int getRowsCount() {
return rowsCount;
}
public void setRowsCount(int rowsCount) {
this.rowsCount = rowsCount;
}
public int getCurrentPage() {
return currentPage;
}
public int getTotalPages() {
return this.totalPages;
}
public void setTotalPages() {
if (this.getTotalRows() == 0) {
this.totalPages = 0;
} else if (this.getPageSize() == 0) {
this.totalPages = 1;
} else {
if (this.getTotalRows() % this.getPageSize() != 0)
this.totalPages = this.getTotalRows() / this.getPageSize() + 1;
else
this.totalPages = this.getTotalRows() / this.getPageSize();
}
}
public void pageFirst() throws java.sql.SQLException {
this.setRowsCount((this.getCurrentPage() - 1) * this.getPageSize() + 1);
}
public void pageLast() throws java.sql.SQLException {
this.setRowsCount((this.getCurrentPage() - 1) * this.getPageSize()
+ this.getCurrentPageRowsCount());
}
}
————————————————————————————
Pageable pgb = new Pageable(rs);
pgb.setPageSize(pageSize);
pgb.gotoPage(page);
if(rs!=null){
rs.absolute(pgb.getRowsCount());
}
do {
if(pgb.getCurrentPageRowsCount()!=0){
id = Integer.parseInt(rs.getString("ID"));
title = rs.getString("Title");
content = rs.getString("Content");
noticeVector.add(new Notice(id, title, content));
}
i++;
} while (rs.next() && i < pgb.getCurrentPageRowsCount());
（GOOD）简化一下，我只想使用分页辅助类Pageable.java，不想使用自定义标签。
1。Pageable.java
2
如下
Pageable pgb = new Pageable(rs);
pgb.setPageSize(10);
pgb.gotoPage(2);
if(rs!=null){
rs.absolute(pgb.getRowsCount());
}
do {
if(pgb.getCurrentPageRowsCount()!=0){
id = Integer.parseInt(rs.getString("ID"));
title = rs.getString("Title");
content = rs.getString("Content");
noticeVector.add(new Notice(id, title, content));
}
i++;
} while (rs.next() && i < pgb.getCurrentPageRowsCount());