Java分页

public class PageBean {
/** 每页显示记录数 */
private int pageCount;
/** 是否有上一页 */
private boolean hasPrevPage;
/** 记录总数 */
private int recordCount;
/** 是否有下一页 */
private boolean hasNextPage;
/**总页面数 */
private int totalPage;
/** 当前页码数 */
private int currentPage;

/**
* 分页前的页面地址
*/
private String pageUrl;

/**
* 输出分页 HTML 页面跳转代码, 分链接和静态文字两种.
* 2008-07-22
* @return HTML 代码
*/
public String getPageJumpLinkHtml() {
if(StringUtil.isEmpty(pageUrl)) {
return "";
}

// 检查是否有参数符号, 没有就加上一个?
if(pageUrl.indexOf('?') == -1) {
pageUrl = pageUrl + '?';
}

StringBuffer buff = new StringBuffer("<span id='pageText'>");

// 上一页翻页标记
if(currentPage > 1) {
buff.append("[ <a href='" + pageUrl + "&page=" + (currentPage - 1) + "' title='转到第 "
+ (currentPage - 1) + " 页'>上一页</a> ] ");
} else {
buff.append("[ 上一页 ] ");
}

// 下一页翻页标记
if(currentPage < getTotalPage()) {
buff.append("[ <a href='" + pageUrl + "&page=" + (currentPage + 1)+ "' title='转到第 "
+ (currentPage + 1) + " 页'>下一页</a> ] ");
} else {
buff.append("[ 下一页 ] ");
}

buff.append("</span>");

return buff.toString();
}

/**
* 输出页码信息: 第${currentPage}页/共${totalPage}页
* @return
*/
public String getPageCountHtml() {
return "第" + currentPage + "页/共" + getTotalPage() + "页";
}

/**
* 输出 JavaScript 跳转函数代码
* @return
*/
public String getJavaScriptJumpCode() {
if(StringUtil.isEmpty(pageUrl)) {
return "";
}

// 检查是否有参数符号, 没有就加上一个?
if(pageUrl.indexOf("?") == -1) {
pageUrl = pageUrl + '?';
}

return "<script>" +
"// 页面跳转函数\n" +
"// 参数: 包含页码的表单元素，例如输入框，下拉框等\n" +
"function jumpPage(input) {\n" +
" // 页码相同就不做跳转\n" +
" if(input.value == " + currentPage + ") {" +
" return;\n" +
" }" +
" var newUrl = '" + pageUrl + "&page=' + input.value;\n" +
" document.location = newUrl;\n" +
" }\n" +
" </script>";

}

/**
* 输出页面跳转的选择框和输入框. 示例输出:
* <pre>
转到
<!-- 输出 HTML SELECT 元素, 并选中当前页面编码 -->
<select onchange='jumpPage(this);'>

<c:forEach var="i" begin="1" end="${totalPage}">
<option value="${i}"

<c:if test="${currentPage == i}">
selected
</c:if>

>第${i}页</option>
</c:forEach>

</select>
输入页码：<input type="text" value="${currentPage}" id="jumpPageBox" size="3">
<input type="button" value="跳转" onclick="jumpPage(document.getElementById('jumpPageBox'))">
</pre>
* @return
*/
public String getPageFormJumpHtml() {
String s = "转到\n" +
"\t <!-- 输出 HTML SELECT 元素, 并选中当前页面编码 -->\n" +
" <select onchange='jumpPage(this);'>\n" +
" \n";

for(int i = 1; i <= getTotalPage(); i++ ) {
s += "<option value=" + i + "\n";

if(currentPage == i) {
s+= " selected ";
}

s += "\t>第" + i + "页</option>\n";
}

s+=
" </select>\n" +
" 输入页码：<input type=\"text\" value=\"" + currentPage + "\" id=\"jumpPageBox\" size=\"3\"> \n" +
" <input type=\"button\" value=\"跳转\" onclick=\"jumpPage(document.getElementById('jumpPageBox'))\"> ";
return s;
}

/**
* 进行分页计算.
*/
private void calculate() {
if (getPageCount() == 0) {
setPageCount(1);
}

totalPage = (int) Math.ceil(1.0 * getRecordCount() / getPageCount()); // 总页面数
if (totalPage == 0)
totalPage = 1;

// Check current page range, 2006-08-03
if(currentPage > totalPage) {
currentPage = totalPage;
}
// System.out.println("currentPage=" + currentPage);
// System.out.println("maxPage=" + maxPage);
// // Fixed logic error at 2004-09-25
hasNextPage = currentPage < totalPage;
hasPrevPage = currentPage > 1;
return;
}

/**
* @return Returns the 最大页面数.
*/
public int getTotalPage() {
calculate();
return totalPage;
}

/**
* @param currentPage
* The 最大页面数 to set.
*/
@SuppressWarnings("unused")
private void setTotalPage(int maxPage) {
this.totalPage = maxPage;
}

/**
* 是否有上一页数据
*/
public boolean hasPrevPage() {
calculate();
return hasPrevPage;
}

/**
* 是否有下一页数据
*/
public boolean hasNextPage() {
calculate();
return hasNextPage;
}

// Test
public static void main(String[] args) {
PageBean pc = new PageBean();
pc.setCurrentPage(2);
pc.setPageCount(4);
pc.setRecordCount(5);
pc.setPageUrl("product/list.do");

System.out.println("当前页 " + pc.getCurrentPage());
System.out.println("有上一页 " + pc.hasPrevPage());
System.out.println("有下一页 " + pc.hasNextPage());
System.out.println("总页面数 " + pc.getTotalPage());

System.out.println("分页 HTML 代码 " + pc.getPageJumpLinkHtml());
}

/**
* @return Returns the 当前页码数.
*/
public int getCurrentPage() {
return currentPage;
}

/**
* 设置当前页码, 从 1 开始.
* @param currentPage
* The 当前页码数 to set.
*/
public void setCurrentPage(int currentPage) {
if (currentPage <= 0) {
currentPage = 1;
}
this.currentPage = currentPage;
}

/**
* @return Returns the recordCount.
*/
public int getRecordCount() {
return recordCount;
}

/**
* @param recordCount
* The recordCount to set.
*/
public void setRecordCount(int property1) {
this.recordCount = property1;
}

/**
* @return Returns the 每页显示记录数.
*/
public int getPageCount() {
return pageCount;
}

/**
* @param pageCount
* The 每页显示记录数 to set.
*/
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}

public String getPageUrl()
{
return pageUrl;
}

public void setPageUrl(String value)
{
pageUrl = value;
}
}