ifcontainstag.java.old

JSP设计（第三版）一书源代码 JSP设计（第三版）》得到了充分的修订和更新

package com.ora.jsp.tags;

import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.jstl.core.*;
import org.apache.taglibs.standard.lang.support.*;

/**
 * This class is a custom action for testing if a String value
 * contains a substring.
 * If it does, the body is evaluated. If a var attribute is provided, 
 * the result is also saved as a Boolean variable in the specified 
 * scope, or in the page if no scope is specified.
 *
 * @author Hans Bergsten, Gefion software <[e-mail]>
 * @version 2.0
 */
public class IfContainsTag extends ConditionalTagSupport {
    private String value;
    private String substring;

    public void setValue(String value) {
	this.value = value;
    }

    public void setSubstring(String substring) {
	this.substring = substring;
    }

    public boolean condition() throws JspTagException {
	if (value == null || substring == null) {
	    throw new JspTagException("ifContains: one of the attributes is null");
	}
	return value.indexOf(substring) != -1;
    }
}