转 ---struts2自定义标签，实现权限认证

工作需要，用到权限控制标签，结合公司项目和网上查阅，弄了个权限标签。其中有一篇文章感觉不错，于是转到自己的博客中。

原文地址：http://buaasss.iteye.com/blog/748247

struts2的自定义标签，需要如下配置，两个类，一个组件类继承org.apache.struts2.components.Component;，一个Tag类继承org.apache.struts2.views.jsp.ComponentTagSupport;，一个tld文件，关联到tag类以及tag类中的各个参数属性，web.xml文件中配置tld位置。

首先组件类，代码都是从原文博客中引用的。

package com.bjsxt.oa.web.tag;

import java.io.Writer;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.components.Component;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.bjsxt.oa.manager.AclManager;
import com.opensymphony.xwork2.util.ValueStack;

public class PermissionComponent extends Component {

	private AclManager aclManager;

	private int userId;

	private String resourceSn;

	private int pn;
	
	public PermissionComponent(ValueStack stack, HttpServletRequest request) {
		super(stack);
		this.setAclManager(request);
	}

	@Override
	public boolean start(Writer writer) {
		boolean result = aclManager.hasPermissionByResourceSn(userId,
				resourceSn, pn);
		System.out.println("result=" + result);
		
		// try {
		// if (result) {
		// writer.write("true");
		// return result;
		// }
		// writer.write("false");
		// } catch (IOException e) {
		// e.printStackTrace();
		// }
		
		//当返回值为true时，body的内容被输出；false时，则被忽略，即不输出
		return result;
	}

	@Override
	public boolean end(Writer writer, String body) {
		return super.end(writer, body);
	}

	public int getUserId() {
		return userId;
	}

	public void setUserId(int userId) {
		this.userId = userId;
	}

	public String getResourceSn() {
		return resourceSn;
	}

	public void setResourceSn(String resourceSn) {
		this.resourceSn = resourceSn;
	}

	public int getPn() {
		return pn;
	}

	public void setPn(int pn) {
		this.pn = pn;
	}

	public void setAclManager(AclManager aclManager) {
		this.aclManager = aclManager;
	}

	public void setAclManager(HttpServletRequest request) {

		WebApplicationContext wac = WebApplicationContextUtils
				.getRequiredWebApplicationContext(request.getSession()
						.getServletContext());

		this.aclManager = (AclManager) wac.getBean("aclManager");
	}

}

然后是tag类

package com.bjsxt.oa.web.tag;

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 PermissionTag extends ComponentTagSupport {

	private static final long serialVersionUID = 1631842497771460718L;

	private int userId;

	private String resourceSn;

	private int pn;

	@Override
	public Component getBean(ValueStack stack, HttpServletRequest request,
			HttpServletResponse arg2) {
		return new PermissionComponent(stack, request);
	}

	@Override
	protected void populateParams() {
		super.populateParams();
		PermissionComponent pct = (PermissionComponent) component;
		pct.setUserId(userId);
		pct.setPn(pn);
		pct.setResourceSn(resourceSn);
	}

	public int getUserId() {
		return userId;
	}

	public void setUserId(int userId) {
		this.userId = userId;
	}

	public String getResourceSn() {
		return resourceSn;
	}

	public void setResourceSn(String resourceSn) {
		this.resourceSn = resourceSn;
	}

	public int getPn() {
		return pn;
	}

	public void setPn(int pn) {
		this.pn = pn;
	}
}

然后是tld文件，tld文件要放到WEB-INF下面，参数说明：这里的required是说此参数在jsp页面中是否为必填的，rtexprvalue是说此参数是否支持动态的设定，也就是为它设定一个从后台中接收的值。name自然就是属性名了。

<?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>2.2.3</tlib-version>
	<jsp-version>1.2</jsp-version>
	<short-name>my</short-name>
	<uri>/jtime</uri>
	<tag>
		<name>permission</name>
		<tag-class>com.bjsxt.oa.web.tag.PermissionTag</tag-class>
		<body-content>JSP</body-content>
		<attribute>
			<name>userId</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
		<attribute>
			<name>resourceSn</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
		<attribute>
			<name>pn</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
	</tag>
</taglib>

 然后就是在web.xml中配置tld文件，这个在原文中没有提及，在这里补充上去。uri是指页面中需要引用的uri地址，location就是我们创建的tld文件的位置。

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<jsp-config>
	<taglib>
	    <taglib-uri>http://com.zilong.haha/ch/</taglib-uri>
	    <taglib-location>/WEB-INF/tld/xxx.tld</taglib-location>
	</taglib>
</jsp-config>

 然后就是jsp文件调用了。自己写吧

<%taglib prefix="zilong" uri="http://com.zilong.haha/ch/"/>//这里就是web.xml种配置的uri路径。
<zilong:namexx  id="" canshux=""/>  namexx就是组件的名称了

 OK!到此为止！