菜鸟用标签做分页

这几天为了做项目而写了一个比较菜的标签，与大家分享，由于本人比较菜，还希望大家多多提宝贵意见！

涉及到分页的一共有3个类：BasePageTag .java，PageTag ,java,StringUtil .java

 

BasePageTag .java

package com.cnc.proud.tag;

import javax.servlet.jsp.tagext.BodyTagSupport;

/**

 @author xueguiping
 *
 */
public class BasePageTag extends BodyTagSupport {

  private static final long serialVersionUID = 5514331269166734936L;

  protected String totalSize; // 总数据量

  protected String avgSize;// 每页数量

  protected String curPage;// 当前页

  protected String url;// 翻页地址

  protected String params;// url参数

  private String tagName;// 标签名称

  private String sign;// 标签名称标识

  public BasePageTag() {
   super();
 }

  public String getAvgSize() {
   return avgSize;
 }

  public void setAvgSize(String avgSize) {
   this.avgSize = avgSize;
 }

  public String getCurPage() {
   return curPage;
 }

  public void setCurPage(String curPage) {
   this.curPage = curPage;
 }

  public String getParams() {
   return params;
 }

  public void setParams(String params) {
   this.params = params;
 }

  public String getSign() {
   return sign;
 }

  public void setSign(String sign) {
   this.sign = sign;
 }

  public String getTagName() {
   return tagName;
 }

  public void setTagName(String tagName) {
   this.tagName = tagName;
 }

  public String getTotalSize() {
   return totalSize;
 }

  public void setTotalSize(String totalSize) {
   this.totalSize = totalSize;
 }

  public String getUrl() {
   return url;
 }

  public void setUrl(String url) {
   this.url = url;
 }

  public void release() {
   super.release();
   this.totalSize = null;
   this.avgSize = null;
   this.curPage = null;
   this.url = null;
   this.params = null;
   this.tagName = null;
   this.sign = null;
 }
}

 

 

PageTag.java

package com.cnc.proud.tag;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;

import com.cnc.proud.util.StringUtil;

/**
 * @author xueguiping
 *
 */
public class PageTag extends BasePageTag {

  private static final long serialVersionUID = -8557518497507464353L;

  private int totalPage;

  private int parseInt(String source) {
   return Integer.parseInt(source);
 }

  public int doStartTag() throws JspException {
   HttpServletRequest request = (HttpServletRequest) this.pageContext
    .getRequest();
   if (StringUtil.isNull(this.totalSize)) {
    this.totalSize = "0";
   } else {
    this.totalSize = this.totalSize.trim();
    this.totalSize = (String) request.getAttribute(this.totalSize);
    if (this.totalSize == null) {
     this.totalSize = "0";
   }
  }
   if (StringUtil.isNull(this.avgSize)) {
    this.avgSize = "10";
   } else {
    this.avgSize = this.avgSize.trim();
    this.avgSize = (String) request.getAttribute(this.avgSize);
    if (this.avgSize == null) {
     this.avgSize = "10";
   }
  }
   if (StringUtil.isNull(this.curPage)) {
    this.curPage = "1";
   } else {
    this.curPage = this.curPage.trim();
    this.curPage = (String) request.getAttribute(this.curPage);
    if (this.curPage == null) {
     this.curPage = "1";
   }
  }
   if (StringUtil.isNull(this.url)) {
    this.url = "";
   } else {
    this.url = this.url.trim();
    this.url = (String) request.getAttribute(this.url);
    if (this.url == null) {
     this.url = "";
   }
  }
   if (StringUtil.isNull(this.params)) {
    this.params = "";
   } else {
    this.params = this.params.trim();
    this.params = (String) request.getAttribute(this.params);
    if (this.params == null) {
     this.params = "";
   }
  }

   this.totalPage = parseInt(this.totalSize) % parseInt(this.avgSize) == 0 ? parseInt(totalSize)
    / parseInt(avgSize)
     : parseInt(totalSize) / parseInt(avgSize) + 1;
   if (parseInt(curPage) < 1) {
    this.curPage = "1";
  }
   if (parseInt(curPage) > totalPage) {
    this.curPage = String.valueOf(totalPage);
  }
   return this.SKIP_BODY;
 }

  public int doEndTag() throws JspException {
   try {
    StringBuffer sb = new StringBuffer();
    JspWriter out = this.pageContext.getOut();
    if (parseInt(this.totalSize) == 0) {
     sb.append(this.getTagName());
    } else {
     if (this.getSign().equals("first")) {
      if (parseInt(this.curPage) == 1) {
       sb.append(this.getTagName());
      } else {
       sb.append("?curPage=1");
      sb.append("&" + this.getParams());
      sb.append("\">" + this.getTagName() + "");
     }
     } else if (this.getSign().equals("previous")) {
      if (parseInt(this.curPage) == 1) {
       sb.append(this.getTagName());
      } else {
       sb.append("?curPage=" + (parseInt(this.curPage) - 1));
      sb.append("&" + this.getParams());
      sb.append("\">" + this.getTagName() + "");
     }
     } else if (this.getSign().equals("next")) {
      if (parseInt(this.curPage) == totalPage) {
       sb.append(this.getTagName());
      } else {
       sb.append("?curPage=" + (parseInt(this.curPage) + 1));
      sb.append("&" + this.getParams());
      sb.append("\">" + this.getTagName() + "");
     }
     } else {
      if (parseInt(this.curPage) == totalPage) {
       sb.append(this.getTagName());
      } else {
       sb.append("?curPage=" + totalPage);
      sb.append("&" + this.getParams());
      sb.append("\">" + this.getTagName() + "");
     }
    }
   }
   out.write(sb.toString());
   } catch (Exception e) {
   System.out.println(e);
   e.printStackTrace();
  }
   return this.EVAL_PAGE;
 }

  public void release() {
   super.release();
   this.totalPage = 0;
 }
}

 

 

package com.cnc.proud.util;

/**
 * 转换字符串
 *
 * @author xueguiping
 */
public class StringUtil {

  public static boolean isNull(Object obj) {
   boolean conditon = false;
  String result = (String) obj;
   if (result == null || result == "" || result.length() < 1) {
    conditon = true;
  }
   return conditon;
 }

}

 

<!----><tlibversion></tlibversion><jspversion></jspversion><shortname></shortname><description></description><tag></tag><name></name><tagclass></tagclass> <bodycontent> </bodycontent> <attribute></attribute><name></name><required></required><rtexprvalue></rtexprvalue><attribute></attribute><name></name><required></required><rtexprvalue></rtexprvalue><attribute></attribute><name></name><required></required><rtexprvalue></rtexprvalue><attribute></attribute><required></required>
<rtexprvalue></rtexprvalue>PageTag.java是组装字符串，用于显示4个标签（首页，上一页，下一页，尾页）BasePageTag.java定义一些标签属性

 

 StringUtil.java用于判断字符串

proud.tld是定义标签（在附件中）

使用方法：

1，先在web.xml中添加标签描述
 

2，然后在action中得到各个参数然后将这些参数放到request中

  request.setAttribute("curPage", String.valueOf(curPage ));
  request.setAttribute("totalSize", String.valueOf(totalSize));
  request.setAttribute("avgSize", String.valueOf(avgSize));
  request.setAttribute("totalPage", String.valueOf(totalPage));
  request.setAttribute("url", url);
  request.setAttribute("params", params);

3，jsp页面中加入<!----> ，然后就可以调用标签，这些标签属性都是从request范围内取值，最终生成的html代码

  

希望大家多提宝贵意见，也希望对初学者能提供帮助！

谢谢!
 

StringUtil .java