webcontext.java

一个实用工具类

/*
 * Copyright (C) butor.com. All rights reserved.
 *
 * This software is published under the terms of the GNU Library General
 * Public License (GNU LGPL), a copy of which has been included with this
 * distribution in the LICENSE.txt file. 
 */


package org.butor.web.context;

import java.io.Serializable;

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

import org.butor.context.DefaultContext;
import org.butor.log.Log;

/**
 * @version 	1.0
 * @author
 */
public class WebContext extends DefaultContext implements IWebContext, Serializable {

	public static final String PROPERTY_HTTP_RESPONSE = "_http_response";
	public static final String PROPERTY_HTTP_SESSION = "_http_session";

	protected HttpServletRequest f_request;
	
	/**
	 * Constructor for DefaultWebContext.
	 */
	public WebContext() {
		super();
	}
	/**
	 * set user profile;
	 */
	public void setSession(HttpSession session) {
		setProperty(PROPERTY_HTTP_SESSION, session);
	}
	/**
	 * set http session;
	 */
	protected HttpSession getSession() {
		return (HttpSession) getProperty(PROPERTY_HTTP_SESSION);
	}
	/**
	 * set http request;
	 */
	public void setRequest(HttpServletRequest request) {
		f_request = request;
	}
	/**
	 * get http request;
	 */
	public HttpServletRequest getRequest() {
		return f_request;
	}
	/**
	 * set http response;
	 */
	public void setResponse(HttpServletResponse response) {
		setProperty(PROPERTY_HTTP_RESPONSE, response);
	}
	/**
	 * get http response;
	 */
	public HttpServletResponse getResponse() {
		return (HttpServletResponse) getProperty(PROPERTY_HTTP_RESPONSE);
	}

	/**
	 * save value permanently into session
	 */
	public boolean saveProperty(String key, Object value) {
		Log.logStr(Log.LOG_LEVEL_LOW, this, Log.LOG_TYPE_INFO, "saveProperty()",
			"saving property key=[" +key +"], value=[" +value +"] into session");

		if (key == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "saveProperty()",
				"Got null key");
			return false;
		}

		HttpSession session = getSession();
		if (session == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "saveProperty()",
				"No session found in context to save property!");
			return false;
		}

		session.setAttribute(key, value);
		
		return true;
	}
	/**
	 * read value from session
	 */
	public Object readProperty(String key) {
		Log.logStr(Log.LOG_LEVEL_LOW, this, Log.LOG_TYPE_INFO, "readProperty()",
			"removing property key=[" +key +"] from session");

		if (key == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "readProperty()",
				"Got null key");
			return null;
		}

		HttpSession session = getSession();
		if (session == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "readProperty()",
				"No session found in context to save property!");
			return null;
		}

		return session.getAttribute(key);
	}
	/**
	 * remove value from session
	 */
	public boolean removeSavedProperty(String key) {
		Log.logStr(Log.LOG_LEVEL_LOW, this, Log.LOG_TYPE_INFO, "removeProperty()",
			"removing property key=[" +key +"] from session");

		if (key == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "removeSavedProperty()",
				"Got null key");
			return false;
		}

		HttpSession session = getSession();
		if (session == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "removeProperty()",
				"No session found in context to save property!");
			return false;
		}

		session.removeAttribute(key);

		return true;
	}
	/**
	 * unset property
	 */
	public boolean removeProperty(String key) {
		if (key == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "removeProperty()",
				"Got null key");
			return false;
		}

		HttpServletRequest request = getRequest();
		if (request != null) {
			Log.logStr(Log.LOG_LEVEL_LOW, this, Log.LOG_TYPE_INFO, "removeProperty()",
				"removing property key=[" +key +"] from request");
			request.removeAttribute(key);
			return true;
		}

		return super.removeProperty(key);
	}
	/**
	 * Sets propertie value
	 */
	public void setProperty(String key, Object value) {
		if (key == null) {
			Log.logStr(this, Log.LOG_TYPE_WARN, "setProperty()",
				"Got null key");
			return;
		}

		HttpServletRequest request = getRequest();
		if (request != null) {
			if (Log.shouldLog(this.getClass().getName(), Log.LOG_LEVEL_LOW)) {
				Log.logStr(this, Log.LOG_TYPE_INFO, "setProperty()",
					"Setting property in request key=[" +key +"] value=[" +value +"]");
			}

			request.setAttribute(key, value);
			return;
		}
		
		super.setProperty(key, value);
	}

	/**
	 * Gets propertie value
	 */
	public Object getProperty(String key) {
		Object value = null;
		HttpServletRequest request = getRequest();
		if (request != null) {
			if (Log.shouldLog(this.getClass().getName(), Log.LOG_LEVEL_LOW)) {
				Log.logStr(this, Log.LOG_TYPE_INFO, "setProperty()",
					"Getting property from request key=[" +key +"]");
			}

			value = request.getAttribute(key);
		}

		if (value == null) {
			value = super.getProperty(key);
		}
		
		return value;
	}
}