struts2 自定义tag标签

在项目中可能有不少相同的jsp页面表示功能，这时可使用自定义的tag进行定义，渐少重复的工做量便于往后维护！

下面就基于struts2进行自定义标签的定义与实现：

首先：自定义类MyTag继承struts2的Component

package cookielogin;

import java.io.IOException;
import java.io.Writer;

import org.apache.struts2.components.Component;

import com.opensymphony.xwork2.util.ValueStack;

public class MyTag extends Component {
	private ValueStack stack;
	private String text;
	private String name;
	private String defaultValue;

	@Override
	public boolean start(Writer writer) {

<span style="white-space:pre">		</span>//这里进行页面的输出
		try {
			writer.write("<h1>" + this.text + "</h1>");
			writer.write("<input name='text' value=");
			writer.write(this.getName());
			writer.write(" name='" + this.getName() + "'>");
		} catch (IOException e) {
			e.printStackTrace();
		}
		return super.start(writer);
	}

	public MyTag(ValueStack stack) {
		super(stack);
		this.stack = stack;
	}

	public ValueStack getStack() {
		return stack;
	}

	public void setStack(ValueStack stack) {
		this.stack = stack;
	}

	public String getText() {
		return text;
	}

	public void setText(String text) {
		this.text = text;
	}

	public String getName() {
		return name;
	}

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

	public String getDefaultValue() {
		return defaultValue;
	}

	public void setDefaultValue(String defaultValue) {
		this.defaultValue = defaultValue;
	}

}

2：指定标签类MyTagSupport继承ComponentTagSupport

package cookielogin;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.components.Component;
import org.apache.struts2.views.jsp.ComponentTagSupport;

import com.opensymphony.xwork2.util.ValueStack;

public class MyTagSupport extends ComponentTagSupport {

	private static final long serialVersionUID = 3586338980857274359L;

	String name;
	String text;

	@Override
	public Component getBean(ValueStack stack, HttpServletRequest req,
			HttpServletResponse res) {
		return new MyTag(stack);
	}

	@Override
	// 设置bean值
	protected void populateParams() {
		System.out.println("开始设置参数！populateParams");
		MyTag tag = (MyTag) getComponent();
		tag.setName(name);
		tag.setText(text);
		tag.setDefaultValue("我就是默认值！咋滴！！");
	}

	public String getName() {
		return name;
	}

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

	public String getText() {
		return text;
	}

	public void setText(String text) {
		this.text = text;
	}

}

java代码完成后，进行配置文件的编写，在WEB-INF/tlds 新建自定义文件tags-custom.tld

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE taglib PUBLIC
	"-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
	"http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">

<taglib>
	<tlib-version>2.0</tlib-version>
	<jsp-version>1.2</jsp-version>
	<short-name>ctags</short-name>
	<uri>http://www.cml.com/tags-custom</uri>
	<description>
	<![CDATA[
		   <p>This is custom tag.</p>
	]]>
	</description>

	<tag>
		<description><![CDATA[我自定义的tag]]></description>
		<name>myTag</name>
		<tag-class>cookielogin.MyTagSupport</tag-class>
		<body-content>JSP</body-content>
		<attribute>
			<description><![CDATA[这个是我自定义的标签]]></description>
			<name>text</name>
			<required>true</required>
		</attribute>
		<attribute>
			<description><![CDATA[这个是我自定义的标签]]></description>
			<name>name</name>
			<required>true</required>
		</attribute>
		<attribute>
			<description><![CDATA[这个是我自定义的标签]]></description>
			<name>defaultValue</name>
			<required>false</required>
		</attribute>
		<dynamic-attributes>false</dynamic-attributes>
	</tag>
	
</taglib>

前提基础工做完成后，在页面引用：

<%@taglib prefix="d" uri="http://www.cml.com/tags-custom"%>
使用：

<d:myTag text="hhahh" name="sdfsd"></d:myTag>

访问页面后出现：

基于struts2的自定义标签实现完毕！虽然功能很简单，可是基本功能已经实现，能够根据项目的实际须要进行编辑！