Struts2通过自定义标签实现权限控制的方法

package qdgxy.tag;
import com.opensymphony.xwork2.util.ValueStack;
import org.apache.struts2.components.Component;
import qdgxy.domain.User;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.io.Writer;
public class AComponent extends Component {
  private String actionURL;
  private String value;
  private String onclick = "";
  private HttpServletRequest request;
  @Override
  public boolean start(Writer writer) {
    HttpSession session = request.getSession();
    User user = (User) session.getAttribute("user");
    if (user.hasPrivilegeByURL(actionURL)) {
      try {
        writer.write("<a href='" + formatURL(actionURL) + "' onClick='" + onclick + "'>" + value + "</a>");
      } catch (IOException e) {
        e.printStackTrace();
      }
      return true;
    } else {
      return super.start(writer);
    }
  }
  private String formatURL(String url) {
    int index = url.indexOf('?');
    if (index != -1) {
      String params = url.substring(index);
      url = url.substring(0, index) + ".action" + params;
    } else {
      url = url + ".action";
    }
    return url;
  }
  public AComponent(ValueStack stack, HttpServletRequest request) {
    super(stack);
    this.request = request;
  }
  public String getActionURL() {
    return actionURL;
  }
  public void setActionURL(String actionURL) {
    this.actionURL = actionURL;
  }
  public String getValue() {
    return value;
  }
  public void setValue(String value) {
    this.value = value;
  }
  public String getOnclick() {
    return onclick;
  }
  public void setOnclick(String onclick) {
    this.onclick = onclick;
  }
}

package qdgxy.tag;
import com.opensymphony.xwork2.util.ValueStack;
import org.apache.struts2.components.Component;
import org.apache.struts2.views.jsp.ComponentTagSupport;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ATag extends ComponentTagSupport {
  private String actionURL;
  private String value;
  private String onclick = "";
  @Override
  public Component getBean(ValueStack valueStack, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) {
    return new AComponent(valueStack, httpServletRequest);
  }
  @Override
  protected void populateParams() {
    AComponent component = (AComponent) getComponent();
    component.setActionURL(actionURL);
    component.setValue(value);
    component.setOnclick(onclick);
  }
  public String getOnclick() {
    return onclick;
  }
  public void setOnclick(String onclick) {
    this.onclick = onclick;
  }
  public String getActionURL() {
    return actionURL;
  }
  public void setActionURL(String actionURL) {
    this.actionURL = actionURL;
  }
  public String getValue() {
    return value;
  }
  public void setValue(String value) {
    this.value = value;
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<taglib>
  <tlib-version>1.0</tlib-version>
  <jsp-version>2.0</jsp-version>
  <short-name>oa</short-name>
  <uri>/WEB-INF/OATag.tld</uri>
  <tag>
    <name>a</name>
    <tag-class>qdgxy.tag.ATag</tag-class>
    <body-content>scriptless</body-content>
    <attribute>
      <name>actionURL</name>
      <required>true</required>
      <rtexprvalue>true</rtexprvalue>
    </attribute>
    <attribute>
      <name>value</name>
      <required>true</required>
      <rtexprvalue>true</rtexprvalue>
    </attribute>
    <attribute>
      <name>onclick</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
    </attribute>
  </tag>
</taglib>