notequaltag.java

java版源代码,里面包含很多源代码,大家可以看看.

package com.trulytech.mantis.tag;

import javax.servlet.jsp.tagext.*;
import java.io.IOException;
import javax.servlet.jsp.JspTagException;
import com.trulytech.mantis.result.DBColumn;
import com.trulytech.mantis.result.DBResult;
import java.util.ArrayList;

/*********************************************
 *
 <bean:notequal name="Result" col="0" row="0" key="22">
 <%String a="aa";%>
 <%=a%>
 </bean:notequal>
 *
 *
 *
 *
 **************************/

/**
 * <p>Title: Mantis</p>
 *
 * <p>Description: 不等于标签</p>
 *
 * <p>Copyright: Copyright (c) 2002</p>
 *
 * <p>Company: </p>
 *
 * @author Wang Xian
 * @version 1.1
 */
public class NotEqualTag
    extends BodyTagSupport {
//行号
  private int Col = 0;
//列号
  private int Row = 0;
//是否等于标志
  private boolean flag = false;
//Bean的名称
  private String Name = null;
//等于的字符
  private String Key = null;

  public void setCol(int Col) {
    this.Col = Col;
  }

  public void setKey(String Key) {
    this.Key = Key;
  }

  public void setName(String Name) {
    this.Name = Name;
  }

  public void setRow(int Row) {
    this.Row = Row;
  }

  /**
   * 覆盖doStartTag方法
   * @return int
   * @throws JspTagException
   */
  public int doStartTag() throws JspTagException {
    String tmpStr = null;
    if (this.pageContext.findAttribute(Name) != null) {
      //如果是DBResult
      if (this.pageContext.findAttribute(Name) instanceof DBResult) {
        if ( ( (DBResult)this.pageContext.findAttribute(Name)).ResultBuffer.
            size() > Row) {
          ArrayList rec = (ArrayList) ( ( (DBResult)this.pageContext.
                                         findAttribute(Name)).ResultBuffer).
              get(Row);
          if (Col >= rec.size())
            tmpStr = "";
          else
            tmpStr = ( (DBColumn) rec.get(Col)).Value;
        }
        else
          tmpStr = "";
      }
      //如果是字符串
      else if (this.pageContext.findAttribute(Name) instanceof String) {
        tmpStr = (String)this.pageContext.findAttribute(Name);
      }
      else {
        tmpStr = "";
      }
    }

    else
      tmpStr = "";

    if (tmpStr == null || Key == null) {
      flag = false;
      return SKIP_BODY;
    }

    else if (tmpStr.equals(Key)) {
      flag = false;
      return SKIP_BODY;
    }
    else {
      flag = true;
      return EVAL_BODY_AGAIN;
    }
  }

  public int doEndTag() throws JspTagException {
    if (flag) {
      try {

        bodyContent.writeOut(bodyContent.getEnclosingWriter());
      }
      catch (IOException e) {
        throw new JspTagException("Fatal error");
      }
    }
    return EVAL_PAGE;
  }

  /**
   * 结束body
   * @return int
   * @throws JspTagException
   */
  public int doAfterBody() throws JspTagException {
    return EVAL_PAGE;

  }

}