?? jb7-1-1.htm
字號(hào):
</o:p>
</span></b></p>
<p class="MsoNormal" style="text-indent:21.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">開發(fā)一個(gè)</span><span lang="EN-US">EJB</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">應(yīng)用程序的工作被分割為六個(gè)分工明確的角色。每一個(gè)角色都是各領(lǐng)域的專家。通過這樣的分割方式，創(chuàng)建和管理一個(gè)分布式系統(tǒng)變得更為容易。</span></p>
<p class="MsoNormal" style="text-indent:21.0pt"><font color="#000080"><b><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">應(yīng)用角色</span><span lang="EN-US">(Application
roles)</span></b></font></p>
<p class="MsoNormal" style="text-indent:21.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">應(yīng)用角色負(fù)責(zé)為</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">編寫代碼和開發(fā)應(yīng)用程序使用它們。雖然標(biāo)準(zhǔn)不同，但這兩個(gè)角色都需要懂得怎樣使商業(yè)邏輯運(yùn)行起來。以下就是著兩個(gè)應(yīng)用角色：</span></p>
<p class="MsoNormal" style="margin-left:57.0pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1;
tab-stops:list 57.0pt"><span lang="EN-US" style="font-family:
Wingdings">l</span><span lang="EN-US">Bean </span><span style="font-family:
宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">開發(fā)者（</span><span lang="EN-US">Bean
provider</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">）</span></p>
<p class="MsoNormal" style="margin-left:57.0pt"><span lang="EN-US">Bean </span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">開發(fā)者創(chuàng)建</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">并編寫</span><span lang="EN-US">enterprise beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">中的商業(yè)邏輯規(guī)則。他們也負(fù)責(zé)定義</span><span lang="EN-US"><span style="mso-tab-count:1">
</span>beans</span><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">的</span><span lang="EN-US">remote</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">和</span><span lang="EN-US">home</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">接口，創(chuàng)建</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">部署描述器（</span><span lang="EN-US">deployment
descriptors</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">）</span><span lang="EN-US">. Bean </span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">開發(fā)者并不需要知道怎樣組合與部署他們的</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">。</span></p>
<p class="MsoNormal" style="margin-left:57.0pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1;
tab-stops:list 57.0pt"><span lang="EN-US" style="font-family:
Wingdings">l</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">應(yīng)用組合者（</span><span lang="EN-US">Application
assembler</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">）</span></p>
<p class="MsoNormal" style="margin-left:57.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">應(yīng)用組合者編寫使用</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">的應(yīng)用程序。這些應(yīng)用程序通常包含其它的組件，列如</span><span lang="EN-US">GUI
clients,applet,JSP</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">和</span><span lang="EN-US">servlets</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">。這些組件被組合入分布式應(yīng)用程序。應(yīng)用組合者要將組合說明添加入</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">部署描述器（</span><span lang="EN-US">deployment
descriptors</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">）。雖然應(yīng)用組合者必須熟悉</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">中包含的方法以用于調(diào)用它們，但他們不必知道這些方法是怎樣實(shí)現(xiàn)的。</span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">對(duì)</span><span lang="EN-US">Enterprise
JavaBeans </span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">感興趣的</span><span lang="EN-US">Jbuilder</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">用戶通常是</span><span lang="EN-US">Bean
</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">開發(fā)者和應(yīng)用組合者。因而主要是為他們編寫的。</span><span lang="EN-US">Jbuilder</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">具有向?qū)А⒃O(shè)計(jì)和其他工具，使用它們可以簡(jiǎn)化</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">和應(yīng)用程序的開發(fā)。</span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman""><font color="#000080">底層結(jié)構(gòu)角色</font></span><span lang="EN-US"><o:p>
</o:p>
</span></b></p>
<p class="MsoNormal" style="margin-left:36.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">沒有底層結(jié)構(gòu)的支持，</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">和使用它們的應(yīng)用程序不能運(yùn)行。雖然兩個(gè)底層結(jié)構(gòu)角色差別很大，但它們總是由同一個(gè)開發(fā)商提供。它們結(jié)合在一起為</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">提供系統(tǒng)級(jí)的服務(wù)運(yùn)行環(huán)境。以下就是這兩個(gè)底層結(jié)構(gòu)角色：</span></p>
<p class="MsoNormal" style="margin-left:57.0pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1;
tab-stops:list 57.0pt"><span lang="EN-US" style="font-family:
Wingdings">l</span><span lang="EN-US">EJB</span><span style="font-family:
宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">服務(wù)器提供者（</span><span lang="EN-US">EJB
server provider</span><span style="font-family:宋體;mso-ascii-font-family:
"Times New Roman";mso-hansi-font-family:"Times New Roman"">）</span></p>
<p class="MsoNormal" style="margin-left:57.0pt"><span lang="EN-US">EJB</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">服務(wù)器提供者是負(fù)責(zé)分布式事務(wù)管理，分布式對(duì)象管理及其它系統(tǒng)級(jí)服務(wù)的專家。他們提供運(yùn)行</span><span lang="EN-US">EJB</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">容器的應(yīng)用框架。</span><span lang="EN-US">EJB</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">服務(wù)器提供者必須至少為</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">提供一個(gè)命名服務(wù)和事務(wù)服務(wù)。</span></p>
<p class="MsoNormal" style="margin-left:57.0pt;text-indent:-21.0pt;mso-list:l0 level1 lfo1;
tab-stops:list 57.0pt"><span lang="EN-US" style="font-family:
Wingdings">l</span><span lang="EN-US">EJB </span><span style="font-family:
宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">容器提供者</span><span lang="EN-US">(EJB
Container Provider)</span></p>
<p class="MsoNormal" style="margin-left:57.0pt"><span lang="EN-US">EJB </span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">容器提供者提供必須的部署工具來部署</span><span lang="EN-US">enterprise
beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">并為處于運(yùn)行狀態(tài)的</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">提供支持。一個(gè)容器可以為一個(gè)或多個(gè)</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">提供管理服務(wù)，它們代替</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">與</span><span lang="EN-US">EJB</span><span style="font-family:
宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">服務(wù)器通信，以訪問</span><span lang="EN-US">beans</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">需要的服務(wù)。</span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">當(dāng)前幾乎所有實(shí)例中，</span><span lang="EN-US">EJB
</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";
mso-hansi-font-family:"Times New Roman"">服務(wù)器提供者和</span><span lang="EN-US">EJB
</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">容器提供者來自同一個(gè)開發(fā)商。例如，</span><span lang="EN-US">Borland
</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">公司的</span><span lang="EN-US">AppServer</span><span style="font-family:宋體;mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:
"Times New Roman"">既提供了服務(wù)器又提供了容器。</span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b><font color="#000080"><span style="font-family:宋體;
mso-ascii-font-family:"Times New Roman";mso-hansi-font-family:"Times New Roman"">部署與運(yùn)行角色</span></font><span lang="EN-US"><font color="#000080"><o:p>
</font>
</o:p>
</span></b></p>
<p class="MsoNormal" style="margin-left:36.0pt"><span style="font-family:宋體;
?? 快捷鍵說明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號(hào)
Ctrl + =
減小字號(hào)
Ctrl + -