linktag.java

strust 框架 的源程序以及java类源代码

/*
 * $Id: LinkTag.java 164530 2005-04-25 03:11:07Z niallp $ 
 *
 * Copyright 1999-2005 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.struts.taglib.html;

import java.net.MalformedURLException;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.jsp.JspException;

import org.apache.struts.taglib.TagUtils;
import org.apache.struts.taglib.logic.IterateTag;
import org.apache.struts.util.MessageResources;

/**
 * Generate a URL-encoded hyperlink to the specified URI.
 *
 * @version $Rev: 164530 $ $Date: 2005-04-25 04:11:07 +0100 (Mon, 25 Apr 2005) $
 */
public class LinkTag extends BaseHandlerTag {


    // ----------------------------------------------------- Instance Variables


    /**
     * The body content of this tag (if any).
     */
    protected String text = null;

    // ----------------------------------------------------- Constructor

    public LinkTag() {
        super();
        doDisabled = false;
    }


    // ------------------------------------------------------------- Properties


    /**
     * The anchor to be added to the end of the generated hyperlink.
     */
    protected String anchor = null;

    public String getAnchor() {
        return (this.anchor);
    }

    public void setAnchor(String anchor) {
        this.anchor = anchor;
    }


    /**
     * <p>The logical forward name from which to retrieve the hyperlink URI.</p>
     * <p>Usage note: If a forward config is used in a hyperlink,
     * and a module is specified, the path must lead to another
     * action and not directly to a page. This is in keeping with
     * rule that in a modular application all links must be to
     * an action rather than a page.
     * </p>
     */
    protected String forward = null;

    public String getForward() {
        return (this.forward);
    }

    public void setForward(String forward) {
        this.forward = forward;
    }


    /**
     * The hyperlink URI.
     */
    protected String href = null;

    public String getHref() {
        return (this.href);
    }

    public void setHref(String href) {
        this.href = href;
    }


    /**
     * The link name for named links.
     */
    protected String linkName = null;

    public String getLinkName() {
        return (this.linkName);
    }

    public void setLinkName(String linkName) {
        this.linkName = linkName;
    }


    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
     MessageResources.getMessageResources(Constants.Package + ".LocalStrings");


    /**
     * The JSP bean name for query parameters.
     */
    protected String name = null;

    public String getName() {
        return (this.name);
    }

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


    /**
     * The module-relative page URL (beginning with a slash) to which
     * this hyperlink will be rendered.
     */
    protected String page = null;

    public String getPage() {
        return (this.page);
    }

    public void setPage(String page) {
        this.page = page;
    }


	/**
	 * The module-relative action (beginning with a slash) which will be
	 * called by this link
	 */
	protected String action = null;

	public String getAction() {
		return (this.action);
	}

	public void setAction(String action) {
		this.action = action;
	}


	/**
	 * The module prefix (beginning with a slash) which will be
	 * used to find the action for this link.
	 */
	protected String module = null;

	public String getModule() {
		return (this.module);
	}

	public void setModule(String module) {
		this.module = module;
	}


    /**
      * The single-parameter request parameter name to generate.
      */
     protected String paramId = null;

    public String getParamId() {
        return (this.paramId);
    }

    public void setParamId(String paramId) {
        this.paramId = paramId;
    }


    /**
     * The single-parameter JSP bean name.
     */
    protected String paramName = null;

    public String getParamName() {
        return (this.paramName);
    }

    public void setParamName(String paramName) {
        this.paramName = paramName;
    }


    /**
     * The single-parameter JSP bean property.
     */
    protected String paramProperty = null;

    public String getParamProperty() {
        return (this.paramProperty);
    }

    public void setParamProperty(String paramProperty) {
        this.paramProperty = paramProperty;
    }


    /**
     * The single-parameter JSP bean scope.
     */
    protected String paramScope = null;

    public String getParamScope() {
        return (this.paramScope);
    }

    public void setParamScope(String paramScope) {
        this.paramScope = paramScope;
    }


    /**
     * The JSP bean property name for query parameters.
     */
    protected String property = null;

    public String getProperty() {
        return (this.property);
    }

    public void setProperty(String property) {
        this.property = property;
    }


    /**
     * The scope of the bean specified by the name property, if any.
     */
    protected String scope = null;

    public String getScope() {
        return (this.scope);
    }

    public void setScope(String scope) {
        this.scope = scope;
    }


    /**
     * The window target.
     */
    protected String target = null;

    public String getTarget() {
        return (this.target);
    }

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


    /**
     * Include transaction token (if any) in the hyperlink?
     */
    protected boolean transaction = false;

    public boolean getTransaction() {
        return (this.transaction);
    }

    public void setTransaction(boolean transaction) {
        this.transaction = transaction;
    }

    /**
     * Name of parameter to generate to hold index number
     */
    protected String indexId = null;

    public String getIndexId() {
       return (this.indexId);
    }

    public void setIndexId(String indexId) {
        this.indexId = indexId;
    }

	protected boolean useLocalEncoding = false;
    
	public boolean isUseLocalEncoding() {
	   return useLocalEncoding;
	}

	public void setUseLocalEncoding(boolean b) {
	   useLocalEncoding = b;
	}

    // --------------------------------------------------------- Public Methods


    /**
     * Render the beginning of the hyperlink.
     * <p>
     * Support for indexed property since Struts 1.1
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {

        // Generate the opening anchor element
        StringBuffer results = new StringBuffer("<a");

        // Special case for name anchors
        prepareAttribute(results, "name", getLinkName());

        // * @since Struts 1.1
        if (getLinkName() == null || getForward() != null  || getHref() != null ||
            getPage() != null || getAction() != null) {
            prepareAttribute(results, "href", calculateURL());
        }
        prepareAttribute(results, "target", getTarget());
        prepareAttribute(results, "accesskey", getAccesskey());
        prepareAttribute(results, "tabindex", getTabindex());
        results.append(prepareStyles());
        results.append(prepareEventHandlers());
        prepareOtherAttributes(results);
        results.append(">");

        TagUtils.getInstance().write(pageContext, results.toString());

        // Evaluate the body of this tag
        this.text = null;
        return (EVAL_BODY_TAG);

    }



    /**
     * Save the associated label from the body content.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doAfterBody() throws JspException {

        if (bodyContent != null) {
            String value = bodyContent.getString().trim();
            if (value.length() > 0)
                text = value;
        }
        return (SKIP_BODY);

    }


    /**
     * Render the end of the hyperlink.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doEndTag() throws JspException {

        // Prepare the textual content and ending element of this hyperlink
        StringBuffer results = new StringBuffer();
        if (text != null) {
            results.append(text);
        }
        results.append("</a>");

        TagUtils.getInstance().write(pageContext, results.toString());

        return (EVAL_PAGE);

    }


    /**
     * Release any acquired resources.
     */
    public void release() {

        super.release();
        anchor = null;
        forward = null;
        href = null;
        linkName = null;
        name = null;
        page = null;
        action = null;
        module = null;
        paramId = null;
        paramName = null;
        paramProperty = null;
        paramScope = null;
        property = null;
        scope = null;
        target = null;
        text = null;
        transaction = false;
        indexId = null;
        useLocalEncoding = false;

    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Return the complete URL to which this hyperlink will direct the user.
     * Support for indexed property since Struts 1.1
     *
     * @exception JspException if an exception is thrown calculating the value
     */
    protected String calculateURL() throws JspException {

        // Identify the parameters we will add to the completed URL
        Map params = TagUtils.getInstance().computeParameters
            (pageContext, paramId, paramName, paramProperty, paramScope,
             name, property, scope, transaction);

        // if "indexed=true", add "index=x" parameter to query string
        // * @since Struts 1.1
        if( indexed ) {

           int indexValue = getIndexValue();

           //calculate index, and add as a parameter
           if (params == null) {
               params = new HashMap();             //create new HashMap if no other params
           }
           if (indexId != null) {
              params.put(indexId, Integer.toString(indexValue));
           } else {
              params.put("index", Integer.toString(indexValue));
           }
        }

        String url = null;
        try {
            url = TagUtils.getInstance().computeURLWithCharEncoding(pageContext, forward, href,
                                          page, action, module, params, anchor, false, useLocalEncoding);
        } catch (MalformedURLException e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException
                (messages.getMessage("rewrite.url", e.toString()));
        }
        return (url);

    }


}