logobodytag.java

J2EE 技术 源码 书籍源代码（j2ee编程技术）

package tag;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
public class LogoBodyTag extends BodyTagSupport {

    //自定义标记属性
    private String heading = null;
    private String image =null;
    private String width =null;
    private String height =null;
  public int doStartTag( ) throws JspException{
          try {
            int h = new Integer(heading).intValue( );
            if(! (h > 0 && h < 7))
        throw new JspException(
        "The 'heading' attribute value must between 1 and 6 inclusive.");
        
    } catch (Exception e) { throw new JspException(e.getMessage( )); }
      return EVAL_BODY_BUFFERED;
    }
  public int doEndTag( ) throws JspException {
    JspWriter out = pageContext.getOut( );
     String imgDir = ((HttpServletRequest) pageContext.
    getRequest( )).getContextPath( )+"\\" ;
        // 获取体内容
String message = getBodyContent( ).getString( ).trim( );

    try{
       //输出体内容
    	 out.println("<img src=\""+ imgDir + image + "\" width=\"" + width +
    	        "\" height=\"" + height + "\" align=\"left\">" + "<H" + heading + ">" +
    	        message.toUpperCase() + "</H" + heading+ ">");

    } catch (java.io.IOException io) {}
   return EVAL_PAGE;

  } //doEndTag
   
  //methods designed to set attribute values
  public void setHeading(String level){

    this.heading= level;

  }
  
  public void setImage(String name){

    this.image = name;

  }
  
  public void setWidth(String width){

    this.width = width;

  }
  
  public void setHeight(String height){

    this.height = height;

  }
  //清空变量，避免标记重用产生问题
  public void release( ){ 
     
     heading = null;
     image =null;
     width =null;
     height =null;
    
  }// release
 }