ParameterMap.java

/*
 * Copyright 2011 Alibaba.com All right reserved. This software is the
 * confidential and proprietary information of Alibaba.com ("Confidential
 * Information"). You shall not disclose such Confidential Information and shall
 * use it only in accordance with the terms of the license agreement you entered
 * into with Alibaba.com.
 */
package com.alibaba.dubbo.governance.web.common.resolver;

import java.util.Collection;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;

import com.alibaba.citrus.turbine.Context;
import com.alibaba.citrus.turbine.TurbineRunDataInternal;

/**
 * ParameterMap
 * 
 * @author william.liangf
 */
public class ParameterMap implements Map<String, Object> {
    
    private static final String CONTEXT_PREFIX = "context.";

    private static final String PARAMETER_PREFIX = "parameter.";

    private static final String HEADER_PREFIX = "header.";
    
    private static final String REQUEST_PREFIX = "request.";
    
    private static final String SESSION_PREFIX = "session.";
    
    private static final String COOKIE_PREFIX = "cookie.";
    
    private static final String APPLICATION_PREFIX = "application.";

    private static final String RUNDATA_PREFIX = "rundata.";

    private static final String METHOD_KEY = REQUEST_PREFIX + "method";

    private static final String REMOTE_HOST_KEY = REQUEST_PREFIX + "remoteHost";

    private static final String CONTEXT_PATH_KEY = REQUEST_PREFIX + "contextPath";
    
    private static final String USER_PRINCIPAL_KEY = REQUEST_PREFIX + "userPrincipal";

    private static final String TARGET_KEY = RUNDATA_PREFIX + "target";

    private static final String FORWARD_KEY = RUNDATA_PREFIX + "forward";

    private static final String BACKWARD_KEY = RUNDATA_PREFIX + "backward";

    private static final String REDIRECT_KEY = RUNDATA_PREFIX + "redirect";

    private static final String REDIRECTED_KEY = RUNDATA_PREFIX + "redirected";

    private static final String LAYOUT_KEY = RUNDATA_PREFIX + "layout";

    private static final String LAYOUT_ENABLED_KEY = RUNDATA_PREFIX + "layoutEnabled";

    private final HttpServletRequest request;
    
    private final Context context;
    
    private final TurbineRunDataInternal rundata;

    @SuppressWarnings("unchecked")
    public ParameterMap(HttpServletRequest request, Context context, TurbineRunDataInternal navigator){
        super();
        this.request = request;
        this.context = context;
        this.rundata = navigator;
        Enumeration<String> keys = request.getParameterNames();
        while (keys.hasMoreElements()) {
            String key = keys.nextElement();
            Object value = getParameterValue(key);
            context.put(key, value);
        }
    }

    public int size() {
        return 0;
    }

    public boolean isEmpty() {
        return false;
    }

    public boolean containsValue(Object value) {
        if (value == null) {
            return false;
        }
        Set<String> keys = context.keySet();
        if (keys != null && keys.size() > 0) {
            for (String key : keys) {
                if (value.equals(context.get(key))) {
                    return true;
                }
            }
        }
        return false;
    }

    public boolean containsKey(Object key) {
        String k = (String) key;
        if (k == null || k.length() == 0) {
            return false;
        }
        return context.containsKey(k) || request.getParameter(k) != null;
    }

    public Object get(Object key) {
        String k = (String) key;
        if (k == null || k.length() == 0) {
            return null;
        }
        if (METHOD_KEY.equals(k)) {
            return request.getMethod();
        } else if (REMOTE_HOST_KEY.equals(k)) {
            return request.getRemoteHost();
        } else if (CONTEXT_PATH_KEY.equals(k)) {
            return request.getContextPath();
        } else if (USER_PRINCIPAL_KEY.equals(k)) {
            return request.getUserPrincipal();
        } else if (TARGET_KEY.equals(k)) {
            return rundata.getTarget();
        } else if (FORWARD_KEY.equals(k)) {
            return rundata.getRedirectTarget();
        } else if (REDIRECT_KEY.equals(k)) {
            return rundata.getRedirectLocation();
        } else if (REDIRECTED_KEY.equals(k)) {
            return rundata.isRedirected();
        } else if (LAYOUT_KEY.equals(k)) {
            return rundata.getLayoutTemplateOverride();
        } else if (LAYOUT_ENABLED_KEY.equals(k)) {
            return rundata.isLayoutEnabled();
        } else if (k.startsWith(CONTEXT_PREFIX)) {
            return context.get(k.substring(CONTEXT_PREFIX.length()));
        } else if (k.startsWith(PARAMETER_PREFIX)) {
            return getParameterValue(k.substring(PARAMETER_PREFIX.length()));
        } else if (k.startsWith(HEADER_PREFIX)) {
            return request.getHeader(k.substring(HEADER_PREFIX.length()));
        } else if (k.startsWith(REQUEST_PREFIX)) {
            return request.getAttribute(k.substring(REQUEST_PREFIX.length()));
        } else if (k.startsWith(SESSION_PREFIX)) {
            return request.getSession().getAttribute(k.substring(SESSION_PREFIX.length()));
        } else if (k.startsWith(COOKIE_PREFIX)) {
            return getCookieValue(k.substring(COOKIE_PREFIX.length()));
        } else if (k.startsWith(APPLICATION_PREFIX)) {
            return request.getSession().getServletContext().getAttribute(k.substring(APPLICATION_PREFIX.length()));
        } else {
            Object value = context.get(k);
            if (value == null) {
                value = getParameterValue(k);
                if (value == null) {
                    value = request.getAttribute(k);
                    if (value == null) {
                        value = request.getSession().getAttribute(k);
                        if (value == null) {
                            value = getCookieValue(k);
                            if (value == null) {
                                value = request.getSession().getServletContext().getAttribute(k);
                            }
                        }
                    }
                }
            }
            return value;
        }
    }
    
    private Object getParameterValue(String key) {
        String[] values = request.getParameterValues(key);
        if (values == null || values.length == 0) {
            return null;
        } else if (values.length == 1) {
            return values[0];
        } else  {
            return values;
        }
    }
    
    private Object getCookieValue(String key) {
        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                if (key.equals(cookie.getName())) {
                    return cookie.getValue();
                }
            }
        }
        return null;
    }

    public Object put(String key, Object value) {
        if (key == null || key.length() == 0) {
            return null;
        }
        if (TARGET_KEY.equals(key)) {
            rundata.setTarget((String) value);
            return null;
        } else if (FORWARD_KEY.equals(key)) {
            rundata.setRedirectTarget((String) value);
            return null;
        } else if (BACKWARD_KEY.equals(key)) {
            rundata.setRedirectLocation(request.getHeader("Referer"));
            return null;
        } else if (REDIRECT_KEY.equals(key)) {
            rundata.setRedirectLocation((String) value);
            return null;
        } else if (LAYOUT_KEY.equals(key)) {
            rundata.setLayout((String) value);
            return null;
        } else if (LAYOUT_ENABLED_KEY.equals(key)) {
            rundata.setLayoutEnabled((Boolean) value);
            return null;
        } else {
            if (key.startsWith(REQUEST_PREFIX)) {
                key = key.substring(APPLICATION_PREFIX.length());
                Object old = request.getAttribute(key);
                if (value == null) {
                    request.removeAttribute(key);
                } else {
                    request.setAttribute(key, value);
                }
                return old;
            } else if (key.startsWith(SESSION_PREFIX)) {
                key = key.substring(APPLICATION_PREFIX.length());
                Object old = request.getSession().getAttribute(key);
                if (value == null) {
                    request.getSession().removeAttribute(key);
                } else {
                    request.getSession().setAttribute(key, value);
                }
                return old;
            } else if (key.startsWith(COOKIE_PREFIX)) {
                key = key.substring(APPLICATION_PREFIX.length());
                Object old = null;
                Cookie[] cookies = request.getCookies();
                if (cookies != null && cookies.length > 0) {
                    for (Cookie cookie : cookies) {
                        if (key.equals(cookie.getName())) {
                            old = cookie.getValue();
                            if (value == null) {
                                cookie.setMaxAge(-1);
                            } else {
                                cookie.setValue((String) value);
                            }
                            break;
                        }
                    }
                }
                return old;
            } else if (key.startsWith(APPLICATION_PREFIX)) {
                key = key.substring(APPLICATION_PREFIX.length());
                Object old = request.getSession().getServletContext().getAttribute(key);
                if (value == null) {
                    request.getSession().getServletContext().removeAttribute(key);
                } else {
                    request.getSession().getServletContext().setAttribute(key, value);
                }
                return old;
            } else {
                if (key.startsWith(APPLICATION_PREFIX)) {
                    key = key.substring(APPLICATION_PREFIX.length());
                }
                Object old = context.get(key);
                if (value == null) {
                    context.remove(key);
                } else {
                    context.put(key, value);
                }
                return old;
            }
        }
    }

    public Object remove(Object key) {
        return put((String) key, null);
    }

    public void putAll(Map<? extends String, ? extends Object> map) {
        if (map != null && map.size() > 0) {
            for (Map.Entry<? extends String, ? extends Object> entry : map.entrySet()) {
                put(entry.getKey(), entry.getValue());
            }
        }
    }

    public void clear() {
        Set<String> keys = context.keySet();
        if (keys != null && keys.size() > 0) {
            for (String key : keys) {
                context.remove(key);
            }
        }
    }

    public Set<String> keySet() {
        return context.keySet();
    }

    public Collection<Object> values() {
        Set<String> keys = context.keySet();
        Set<Object> values = new HashSet<Object>();
        if (keys != null && keys.size() > 0) {
            for (String key : keys) {
                values.add(context.get(key));
            }
        }
        return values;
    }

    public Set<Entry<String, Object>> entrySet() {
        Set<String> keys = context.keySet();
        Set<Entry<String, Object>> entries = new HashSet<Entry<String, Object>>();
        if (keys != null && keys.size() > 0) {
            for (String key : keys) {
                entries.add(new ParameterEntry(key));
            }
        }
        return entries;
    }
    
    private class ParameterEntry implements Entry<String, Object> {

        private final String key;
        
        private volatile Object value;

        public ParameterEntry(String key){
            this.key = key;
            this.value = ParameterMap.this.get(key);
        }

        public String getKey() {
            return key;
        }

        public Object getValue() {
            return value;
        }

        public Object setValue(Object value) {
            this.value = value;
            return ParameterMap.this.put(key, value);
        }

    }

}