ofbiz實體引擎(九) 多租戶

多租戶在平臺中是根據delegator不同操作不同的數據庫

  /**
     * @author 鄭小康
     * 設置完整的delegator  其可能形式有 default 或者defalut#tenantDelegatorName
     * 針對於第一種情況 delegatorBaseName =="default" delegatorTenantId=null
     * 針對第二種情況 delegatorBaseName =="default"  delegatorTenantId="tenantDelegatorName"
     * 爲什麼存在第二種情況，是因爲在多租戶中要實現數據獨立，所以獲取基礎delagtor 和租戶delegator,注意這時並未創建實例更沒有建立數據庫連接
     * 其再獲取了默認的delegator中的信息之後，如果存在delegatorBaseName 則將 uri username password進行覆蓋
     * */
    protected void setDelegatorNames(String delegatorFullName) {
        this.delegatorFullName = delegatorFullName;

        int hashSymbolIndex = delegatorFullName.indexOf('#');
        if (hashSymbolIndex == -1) {
            this.delegatorBaseName = delegatorFullName;
        } else {
            this.delegatorBaseName = delegatorFullName.substring(0, hashSymbolIndex);
            this.delegatorTenantId = delegatorFullName.substring(hashSymbolIndex + 1);
        }
    }

//多租戶 根據默認baseDelegator獲取域名對應TenantId 拼接DelegatorName獲取其實例
if (useMultitenant) {
            // get tenant delegator by domain name，獲取服務名
            String serverName = httpRequest.getServerName();
            try {
            	
                // if tenant was specified, replace delegator with the new per-tenant delegator and set tenantId to session attribute
                Delegator delegator = getDelegator(config.getServletContext());

                //Use base delegator for fetching data from entity of entityGroup com.hanlin.fadp.tenant 
                Delegator baseDelegator = DelegatorFactory.getDelegator(delegator.getDelegatorBaseName());
                GenericValue tenantDomainName = EntityQuery.use(baseDelegator).from("TenantDomainName").where("domainName", serverName).queryOne();
                String tenantId = null;
                if(UtilValidate.isNotEmpty(tenantDomainName)) {
                    tenantId = tenantDomainName.getString("tenantId");
                }
                
                if(UtilValidate.isEmpty(tenantId)) {
                    tenantId = (String) httpRequest.getAttribute("userTenantId");
                }
                if(UtilValidate.isEmpty(tenantId)) {
                    tenantId = (String) httpRequest.getParameter("userTenantId");
                }
                if (UtilValidate.isNotEmpty(tenantId)) {
                    // if the request path is a root mount then redirect to the initial path
                    if (UtilValidate.isNotEmpty(requestPath) && requestPath.equals(contextUri)) {
                        GenericValue tenant = EntityQuery.use(baseDelegator).from("Tenant").where("tenantId", tenantId).queryOne();
                        String initialPath = tenant.getString("initialPath");
                        if (UtilValidate.isNotEmpty(initialPath) && !"/".equals(initialPath)) {
                            ((HttpServletResponse)response).sendRedirect(initialPath);
                            return;
                        }
                    }

                    // make that tenant active, setup a new delegator and a new dispatcher
                    String tenantDelegatorName = delegator.getDelegatorBaseName() + "#" + tenantId;
                    httpRequest.getSession().setAttribute("delegatorName", tenantDelegatorName);

                    // after this line the delegator is replaced with the new per-tenant delegator
                    delegator = DelegatorFactory.getDelegator(tenantDelegatorName);
                    config.getServletContext().setAttribute("delegator", delegator);

                    // clear web context objects
                    config.getServletContext().setAttribute("security", null);
                    config.getServletContext().setAttribute("dispatcher", null);

                    /**
                     * 初始化security，根據delegatorName先從緩存中獲取，如果緩存中不存在對應的security，則實例化一個
                     * 由於該過濾器是每次請求都會經過，所以根據域名不同，獲取的security就有所不同，這樣就可以實現共用一套用戶表在不同租戶中權限不同
                     */
                    Security security = getSecurity();
                    // initialize the services dispatcher
                    LocalDispatcher dispatcher = getDispatcher(config.getServletContext());

                    // set web context objects
                    request.setAttribute("dispatcher", dispatcher);
                    request.setAttribute("security", security);
                    
                    request.setAttribute("userTenantId", tenantId);
                }

                // NOTE DEJ20101130: do NOT always put the delegator name in the user's session because the user may 
                // have logged in and specified a tenant, and even if no Tenant record with a matching domainName field 
                // is found this will change the user's delegator back to the base one instead of the one for the 
                // tenant specified on login 
                // httpRequest.getSession().setAttribute("delegatorName", delegator.getDelegatorName());
            } catch (GenericEntityException e) {
                Debug.logWarning(e, "Unable to get Tenant沒有獲取這個租戶", module);
            }
        }