J2EE自定义mvc【框架配置及功能】

package com.zking.tag; import com.zking.util.PageBean; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspWriter; import javax.servlet.jsp.tagext.BodyTagSupport; import java.io.IOException; import java.util.Map; import java.util.Set; /** * Page助手类 * * @author tgq * */ public class PageTag extends BodyTagSupport { private static final long serialVersionUID = 1L; private PageBean pageBean; public PageBean getPageBean() { return pageBean; } public void setPageBean(PageBean pageBean) { this.pageBean = pageBean; } @Override public int doStartTag() throws JspException { // 获取流 JspWriter out = pageContext.getOut(); try { out.print(toHTML()); } catch (IOException e) { e.printStackTrace(); } return SKIP_BODY; } /** * JSP自定义页面内容展示 * * @return */ private String toHTML() { StringBuilder sb = new StringBuilder(); // 这里拼接的是一个上一次发送的请求以及携带的参数，唯一改变的就是页码 sb.append("<form id='pageBeanForm' action='" + pageBean.getUrl() + "' method='post'>"); sb.append("<input type='hidden' name='page'>"); // 重要设置拼接操作，将上一次请求参数携带到下一次 Map<String, String[]> paMap = pageBean.getParameterMap(); if (paMap != null && paMap.size() > 0) { Set<Map.Entry<String, String[]>> entrySet = paMap.entrySet(); for (Map.Entry<String, String[]> entry : entrySet) { for (String val : entry.getValue()) { if (!"page".equals(entry.getKey())) { sb.append("<input type='hidden' name='" + entry.getKey() + "' value='" + val + "'>"); } } } } sb.append("</form>"); /** * 页码数据配置 */ int page = pageBean.getPage(); // 当前页码 int max = pageBean.getMaxPage();// 最大页码 int before = page > 4 ? 4 : page - 1;// 当前页码前面的页码 int after = 10 - 1 - before;// 当前页码后面的页码 // 如果最大页码没有10页，就显示当前页面后面的所有页码 max - page after = page + after > max ? max - page : after; // 初始页码和结束页码值判断 disabled boolean startFlag = page == 1; boolean endFlag = max == page; // 拼接分页条 sb.append("<ul class='pagination'>"); sb.append("<li class='page-item " + (startFlag ? "disabled" : "") + "'><a class='page-link' href='javascript:gotoPage(1)'>首页</a></li>"); sb.append("<li class='page-item " + (startFlag ? "disabled" : "") + "'><a class='page-link' href='javascript:gotoPage(" + pageBean.getPrevPage() + ")'>&lt;</a></li>"); // 代表了当前页的前4页 for (int i = before; i > 0; i--) { sb.append("<li class='page-item'><a class='page-link' href='javascript:gotoPage(" + (page - i) + ")'>" + (page - i) + "</a></li>"); } sb.append("<li class='page-item active'><a class='page-link' href='javascript:gotoPage(" + pageBean.getPage() + ")'>" + pageBean.getPage() + "</a></li>"); // 代表了当前页的后5页 for (int i = 1; i <= after; i++) { sb.append("<li class='page-item'><a class='page-link' href='javascript:gotoPage(" + (page + i) + ")'>" + (page + i) + "</a></li>"); } sb.append("<li class='page-item " + (endFlag ? "disabled" : "") + "'><a class='page-link' href='javascript:gotoPage(" + pageBean.getNextPage() + ")'>&gt;</a></li>"); sb.append("<li class='page-item " + (endFlag ? "disabled" : "") + "'><a class='page-link' href='javascript:gotoPage(" + pageBean.getMaxPage() + ")'>尾页</a></li>"); sb.append( "<li class='page-item go-input'><b>到第</b><input class='page-link' type='text' id='skipPage' name='' /><b>页</b></li>"); sb.append("<li class='page-item go'><a class='page-link' href='javascript:skipPage()'>确定</a></li>"); sb.append("<li class='page-item'><b>共" + pageBean.getTotal() + "条</b></li>"); sb.append("</ul>"); // 拼接分页的js代码 sb.append("<script type='text/javascript'>"); sb.append("function gotoPage(page) {"); sb.append("document.getElementById('pageBeanForm').page.value = page;"); sb.append("document.getElementById('pageBeanForm').submit();"); sb.append("}"); sb.append("function skipPage() {"); sb.append("var page = document.getElementById('skipPage').value;"); sb.append("if (!page || isNaN(page) || parseInt(page) < 1 || parseInt(page) > " + max + ") {"); sb.append("alert('请输入1~N的数字');"); sb.append("return;"); sb.append("}"); sb.append("gotoPage(page);"); sb.append("}"); sb.append("</script>"); return sb.toString(); } }