JSP自定义标签

感觉自己写一个Button的标签库

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;

import cq.myUtil.util.StringUtil;

public class ButtonTag extends BodyTagSupport {

	// 按钮的id
	private String id;
	// 按钮的name
	private String name;
	// 按钮不可用
	private String disabled;
	// 传进来的参数，是link就传url进来。是action 就传action进来。
	private String parames;
	// 按钮的class
	private String htmlClass;
	// 按钮的样式
	private String style;
	// 按钮上面的名字
	private String value;
	// 打开页面的类型
	private String target;
	// 类型非为三种 link submit button reset
	private String btntype;
	// 单击事件
	private String onclick;

	public void setBtntype(String btntype) {
		this.btntype = btntype;
	}

	public void setId(String id) {
		this.id = id;
	}

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

	public void setDisabled(String disabled) {
		this.disabled = disabled;
	}

	public void setParames(String parames) {
		this.parames = parames;
	}

	public void setHtmlClass(String htmlClass) {
		this.htmlClass = htmlClass;
	}

	public void setStyle(String style) {
		this.style = style;
	}

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

	public void setTarget(String target) {
		this.target = target;
	}

	public void setOnclick(String onclick) {
		this.onclick = onclick;
	}

	@Override
	public int doStartTag() throws JspException {
		StringBuilder builder = new StringBuilder();
		builder.append("<input ");
		if ((btntype != null) && (btntype.equals("submit"))) {
			builder.append("type='submit' ");
		} else if ((btntype != null) && (btntype.equals("button"))) {
			builder.append("type='button'  ");
		} else if ((btntype != null) && (btntype.equals("reset"))) {
			builder.append("type='reset' ");
		} else {
			if (StringUtil.isEmpty(target)) {
				target = "_self";
			}
			builder.append("type='button' onclick=\"javascript:window.open(\'" + parames + "\',\'" + target+ "\');\"");
		}
		builder.append("value ='" + value + "' ");
		if (!StringUtil.isEmpty(id)) {
			builder.append("id='" + id + "'  ");
		}
		if (!StringUtil.isEmpty(name)) {
			builder.append("name='" + name + "'  ");
		}
		if (!StringUtil.isEmpty(disabled)) {
			if (!disabled.equals("false")) {
				builder.append("disabled='" + disabled + "'  ");
			} 
		}
		if (!StringUtil.isEmpty(onclick)) {
			builder.append("onclick='" + onclick + "'  ");
		}
		if (!StringUtil.isEmpty(htmlClass)) {
			builder.append("class='" + htmlClass + "' ");
		}
		if (!StringUtil.isEmpty(style)) {
			builder.append("style ='" + style + "' ");
		}

		builder.append(" />");

		try {
			pageContext.getOut().write(builder.toString());
		} catch (Throwable cause) {
			throw new RuntimeException("自定义按钮标签出错", cause);
		}
		return SKIP_BODY;
	}
}

定义一个tld的文件,在写JSP的时候把这个Tld文件包含进去

<tag>
	    <name>button</name>
	    <tagclass>cq.nfs.tag.ButtonTag</tagclass>
	    <bodycontent>JSP</bodycontent>
	    <attribute>
	    	<name>id</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>name</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>btntype</name>
	    	<required>true</required>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>parames</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>htmlClass</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>disabled</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>style</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>value</name>
	    	<required>true</required>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>target</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	    <attribute>
	    	<name>onclick</name>
	    	<rtexprvalue>true</rtexprvalue>
	    </attribute>
	</tag>

集合类中的方法

	public static boolean isEmpty(Object str) {
		if (str == null) {
			return true;
		}
		return str.toString().matches("\\s*");
	}