JSP自定义分页标签TAG全过程(2)

public abstract class Page { protected VariablePage variablePage; public Page(VariablePage variablePage) { this.variablePage = variablePage; calculateTotalPage(); } public int getStartIndex() { return (getValidpageNum() - 1) * variablePage.pageSize; } public String getBackpageNum() { if (variablePage.pageNo <= 1) { return buildSpan("上一页", variablePage); } else { return buildA("上一页", variablePage.getUrl() + (variablePage.pageNo - 1)); } } public String getNextpageNum() { if (variablePage.pageNo >= variablePage.totalPage) { return buildSpan("下一页", variablePage); } else { return buildA("下一页", variablePage.getUrl() + (variablePage.pageNo + 1)); } } /** * 计算总页数 */ private void calculateTotalPage() { if (variablePage.totalSum % variablePage.pageSize == 0) { variablePage.totalPage = variablePage.totalSum / variablePage.pageSize; } else { variablePage.totalPage = variablePage.totalSum / variablePage.pageSize + 1; } if (variablePage.totalPage < variablePage.pageNo) { variablePage.pageNo = variablePage.totalPage; } else if (variablePage.pageNo < 1) { variablePage.pageNo = 1; } } protected String displayAll() { StringBuilder sBuilder = new StringBuilder(10); sBuilder.append(variablePage.split); for (int i = 1; i <= variablePage.totalPage; i++) { if (i == variablePage.pageNo) { sBuilder.append(i + variablePage.split); } else { sBuilder.append(buildA(variablePage, i) + variablePage.split); } } return sBuilder.toString(); } /** * 抽象出分页方法 * * @return */ public abstract String pagination(); /** * 实现从第一页开始打印 * * @return */ protected final String fromFirstPagePrint() { StringBuffer buffer = new StringBuffer(100); for (int i = 1; i <= variablePage.showPageNum; i++) { if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL buffer.append(i + variablePage.split); } else { buffer.append(buildA(variablePage, i) + variablePage.split); } } return buffer.toString(); } /** * 实现从最后一页开始打印 * * @return */ protected final String fromLastPagePrint() { StringBuffer buffer = new StringBuffer(100); int startPage = variablePage.totalPage - (variablePage.showPageNum - 1); for (int i = startPage; i <= variablePage.totalPage; i++) { if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL buffer.append(i + variablePage.split); } else { buffer.append(buildA(variablePage, i) + variablePage.split); } } return buffer.toString(); } public String getFirstNo() { if (isExistsPagination()) { return buildA("首页", variablePage.url + 1); } else { return buildSpan("首页", variablePage); } } /** * 判断是否存在分页 * * @return */ private boolean isExistsPagination() { if (variablePage.totalSum > 1 && variablePage.totalPage > 1) { return true; } return false; } public String getLastNo() { if (isExistsPagination()) { return buildA("尾页", variablePage.url + variablePage.totalPage); } else { return buildSpan("尾页", variablePage); } } protected int getValidpageNum() { if (variablePage.totalPage < variablePage.pageNo) { return variablePage.pageNo = variablePage.totalPage; } else if (variablePage.pageNo < 1) { return variablePage.pageNo = 1; } else { return variablePage.pageNo; } } public VariablePage getPageContant() { return this.variablePage; } public abstract String buildSpan(String text, VariablePage variablePage); public abstract String buildA(String text, String url); public abstract String buildA(VariablePage variablePage, int num); public String printModifyPageSize(int pageSize){ StringBuilder builder=new StringBuilder(100); builder.append("每页<input type='text' maxlength='2'"); if(pageSize>0){ builder.append(" value='"+pageSize+"' "); } builder.append("/>条"); return builder.toString(); } }