java 模仿google的分页代码

package com.nick.navigation; import java.io.IOException; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspWriter; import javax.servlet.jsp.tagext.BodyTagSupport; public class MyNavigationTag extends BodyTagSupport { private static final long serialVersionUID = -4247241487535299862L; private String indexColor = ""; private String countColor = ""; private String navigationUrl = ""; private int pageIndex; private int pageCount; // 自定义参数 private String params = ""; public int getPageCount() { return pageCount; } public void setPageCount(int pageCount) { this.pageCount = pageCount; } public int getPageIndex() { return pageIndex; } public void setPageIndex(int pageIndex) { this.pageIndex = pageIndex; } @Override public int doStartTag() throws JspException { // 获取url navigationUrl = getParameterUrl(); // 设置显示页数的颜色 getColor(); StringBuffer strb = new StringBuffer(); // 分页 int front = pageIndex - 4; // 前面一截 int back = pageIndex + 4; // 后面一截 if (pageIndex == 1) { strb.append(" 首页 "); strb.append(" 上一页 "); } else { strb.append("<a href=" + navigationUrl + "pageIndex=1> 首页 </a>"); strb.append("<a href=" + navigationUrl + "pageIndex=" + (pageIndex - 1) + "> 上一页 </a> "); } if (pageIndex < 5) // 如果索引在前5页 { if (pageCount <= 10) // 总页数不够10页 { for (int i = 1; i <= pageCount; i++) { if (i == pageIndex) strb.append(" " + pageIndex + " "); else strb.append("<a href=" + navigationUrl + "pageIndex=" + i + ">[" + i + "]</a>"); } } else { for (int i = 1; i < 10; i++) { if (i == pageIndex) strb.append(" " + pageIndex + " "); else strb.append("<a href=" + navigationUrl + "pageIndex=" + i + ">[" + i + "]</a>"); } } } else { if (front >= 1) { for (int i = 4; i > 0; i--) strb.append("<a href=" + navigationUrl + "pageIndex=" + (pageIndex - i) + ">[" + (pageIndex - i) + "]</a>"); } else { for (int i = 1; i < pageIndex; i++) strb.append("<a href=" + navigationUrl + "pageIndex=" + i + ">[" + i + "]</a>"); } strb.append(" " + pageIndex + " "); // 分界线 eg: 5 // ,前面一截就是1234,后面一截就是6789 if (back <= pageCount) { for (int i = 1; i < 5; i++) strb.append("<a href=" + navigationUrl + "pageIndex=" + (pageIndex + i) + ">[" + (pageIndex + i) + "]</a>"); } else { for (int i = 1; i < pageCount - pageIndex + 1; i++) strb.append("<a href=" + navigationUrl + "pageIndex=" + (pageIndex + i) + ">[" + (pageIndex + i) + "]</a>"); } } if (pageIndex == pageCount) { strb.append(" 下一页 "); strb.append(" 最后一页 "); } else { strb.append(" <a href=" + navigationUrl + "pageIndex=" + (pageIndex + 1) + "> 下一页 </a>"); strb.append("<a href=" + navigationUrl + "pageIndex=" + pageCount + "> 最后一页 </a>"); } strb.append(" <font color=" + indexColor + ">" + pageIndex + "</font>/<font color=" + countColor + ">" + pageCount + "</font>"); JspWriter out = pageContext.getOut(); try { out.println(strb.toString()); } catch (IOException e) { e.printStackTrace(); } return EVAL_PAGE; } private void getColor() { if (indexColor.equals("")) indexColor = "red"; if (countColor.equals("")) countColor = "blue"; } private String getParameterUrl() { System.out.println("params | "+params); // 没有自定义参数 if (params.equals("")) return navigationUrl; StringBuffer url = new StringBuffer(); url.append(navigationUrl).append("?").append(params).append("&"); return url.toString(); } public String getNavigationUrl() { return navigationUrl; } public void setNavigationUrl(String navigationUrl) { this.navigationUrl = navigationUrl; } public String getCountColor() { return countColor; } public void setCountColor(String countColor) { this.countColor = countColor; } public String getIndexColor() { return indexColor; } public void setIndexColor(String indexColor) { this.indexColor = indexColor; } public String getParams() { return params; } public void setParams(String params) { this.params = params; } }