引入:html
由於項目需求,咱們要用到openCMS。雖然之前用過不少相似的內容管理系統相似Vignette,Fatwire,可是openCMS雖然大致功能差很少,具體並沒用過,因此這裏作了一些研究,會陸續把這些研究心得分享出來。這裏先從openCMS安裝講起,雖然簡單,但也有一些值得探討的問題。java
安裝亮點1:不能夠重複配置openCMS。mysql
咱們知道,第一次運行openCMS須要作配置,配置的請求URL是:http://localhost:8080/opencms/setup/ ,可是運行第一次以後就不能夠運行第二次了,理由是在安裝過程當中,它會去調用CmsSetupBean類的prepareSetup10()方法:sql
/** * Prepares step 10 of the setup wizard.<p> */ publicvoidprepareStep10() { if (isInitialized()) { // lock the wizard for further use lockWizard(); // save Properties to file "opencms.properties" saveProperties(getProperties(),CmsSystemInfo.FILE_PROPERTIES, false); setSchemaGeneration(false); m_peristenceConfigurator.save(); } }
而這個方法會去調用lockWizard()方法後保存opencms.properties讓其生效,lockWizard方法的實現就是把opencms.properties中key爲wizard.enabled設爲false:數據庫
publicvoidlockWizard() { setExtProperty("wizard.enabled", CmsStringUtil.FALSE); }
這會致使咱們的opencms.properties被更改:服務器
# # Enable/Disable OpenCms Setup Wizard # The wizard sets the flag to false after the setup. # To use the wizard again, reset it manually to true. # By setting no value, wizard can always be used. ################################################################################# wizard.enabled=false
而下次運行時候,它會去判斷此屬性,判斷點在CmsAutoSetup類的main()方法中調用的run()方法的第一行:app
/** * Performs the setup.<p> * @throws Exception */ publicvoidrun() throwsException { if (m_bean.getWizardEnabled()) { longtimeStarted = System.currentTimeMillis(); CmsSetupTests setupTests = new CmsSetupTests(); … } }
安裝亮點2: 正確設置max_allowed_packet這個mysql系統變量的大小。less
在opencms安裝過程當中,它會對一些DB變量作檢查,其代碼以下:ide
/** * Returns an optional warning message ifneeded, <code>null</code> if not.<p> * * @param db the selected database key * * @return html warning, or <code>null</code> if no warning */ publicString checkVariables(String db) { StringBuffer html = new StringBuffer(512); if (m_con == null){ return null; // prior error,trying to get a connection } Exception exception = null; if (db.equals("mysql")){ String statement = "SELECT @@max_allowed_packet;"; Statement stmt = null; ResultSet rs = null; longmaxAllowedPacket = 0; try { stmt = m_con.createStatement(); rs = stmt.executeQuery(statement); if (rs.next()) { maxAllowedPacket = rs.getLong(1); } } catch (Exception e) { exception = e; } finally { if (stmt != null){ try { stmt.close(); } catch (SQLException e) { // ignore } } } if (exception == null){ intmegabyte = 1024 * 1024; if (maxAllowedPacket > 0) { html.append("<p>MySQL system variable <code>'max_allowed_packet'</code>is set to "); html.append(maxAllowedPacket); html.append(" Byte ("); html.append((maxAllowedPacket / megabyte) + "MB).</p>\n"); } html.append("<p>Please note that it will not be possible for OpenCms tohandle files bigger than this value in the VFS.</p>\n"); intrequiredMaxAllowdPacket = 16; if (maxAllowedPacket < (requiredMaxAllowdPacket * megabyte)){ m_errors.add("<p><b>Your <code>'max_allowed_packet'</code>variable is set to less than " + (requiredMaxAllowdPacket* megabyte) + " Byte(" + requiredMaxAllowdPacket + "MB).</b></p>\n" + "<p>The required value for running OpenCms isat least " + requiredMaxAllowdPacket + "MB." + "Please change your MySQL configuration (in the<code>my.ini</code> or <code>my.cnf</code>file).</p>\n"); } } else { html.append("<p><i>OpenCms was not able to detect the value of your<code>'max_allowed_packet'</code>variable.</i></p>\n"); html.append("<p>Please note that it will not be possible for OpenCms tohandle files bigger than this value.</p>\n"); html.append("<p><b>The recommended value for running OpenCms is 16MB,please set it in your MySQL configuration (in your<code>my.ini</code> or <code>my.cnf</code>file).</b></p>\n"); html.append(CmsException.getStackTraceAsString(exception)); } } if (html.length() == 0) { return null; } return html.toString(); }
從這裏能夠看出,對於數據庫是mysql的情形,它會先去執行數據庫查詢讀取max_allowed_packet的值,這個變量主要讓mysql限制服務器接受的單個數據包的大小(由於在openCMS中,常常要存富文本內容,因此這個值仍是要設置大點爲好),而且若是它<16MB, 則報錯our max_allowed_packet variable is set to less than 16MB。而默認的mysql這個值配置是4MB,因此第一次setup出錯。咱們在my.ini中將其改成30MB,這樣才過了這關:ui
安裝亮點3:opencms中資產的存儲。
opencms中,這些資產都是以BLOB形式存儲的: