📄 ws-j2x-4-6.html
字号:
</TR>
<TR>
<TD bgcolor="#000000" height="1" width="150"><IMG src="../i/c.gif" width="150" height="1"></TD>
</TR>
<TR>
<TD bgcolor="#ffffff" height="1" width="150"><IMG src="../i/c.gif" width="150" height="2"></TD>
</TR>
</TABLE>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td><font size="-1" face="Verdana, sans-serif"><a href="http://www.ibm.com/">IBM</a> : <a href="/developerWorks/cn/index.shtml">developerWorks 中国网站</a> : <a href="/developerWorks/cn/xml/index.shtml">xml</a> ： <a href="/developerWorks/cn/cnedu.nsf/xml-onlinecourse-bytitle">教学 - 在线教程</a></font>
<br>
<img alt="用 XDoclet 来改进 J2EE 组件的重用" src="imagemaster/masthead.jpg"></td><td width="*" valign="bottom" align="right"><a border="0" href="ws-j2x.zip"><img alt="下载 ZIP 文件" border="0" src="../i/icon-zip.gif"></a><a target="_blank" href="../tutorial_eng/index.html" border="0"><img alt="英文原文" border="0" src="../i/icon-source.gif"></a>
</td>
</tr>
<tr>
<td height="2" colspan="2"><img height="2" width="1" src="../i/c.gif"></td>
</tr>
</table>
<TABLE border="0" cellpadding="0" cellspacing="0" width="100%">
<TR>
<TD width="150" height="1" bgcolor="#000000" colspan="6"><IMG alt="" height="1" width="150" src="../i/c.gif"></TD>
</TR>
<TR>
<TD background="../i/sw-gold.gif"><a border="0" href="index.html" onMouseOver="iOver('topmain'); iOver('bottommain'); self.status=mainblurb; return true;" onMouseOut="iOut('topmain'); iOut('bottommain'); self.status=''; return true;"><img alt="主菜单" border="0" src="../i/main.gif" name="topmain"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topsection'); iOver('bottomsection'); self.status=sectionblurb; return true;" onMouseOut="iOut('topsection'); iOut('bottomsection'); self.status=''; return true;" href="index4.html"><img alt="章节菜单" border="0" src="../i/section.gif" name="topsection"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topfeedback'); iOver('bottomfeedback'); self.status=feedbackblurb; return true;" onMouseOut="iOut('topfeedback'); iOut('bottomfeedback'); self.status=''; return true;" href="ws-j2x-6-3.html"><img alt="给出此教程的反馈意见" border="0" src="../i/feedback.gif" name="topfeedback"></a></TD><TD width="100%" background="../i/sw-gold.gif"><img src="../i/c.gif"></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topprevious'); iOver('bottomprevious'); self.status=previousblurb; return true;" onMouseOut="iOut('topprevious'); iOut('bottomprevious'); self.status=''; return true;" href="ws-j2x-4-5.html"><img alt="上页" border="0" src="../i/previous.gif" name="topprevious"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topnext'); iOver('bottomnext'); self.status=nextblurb; return true;" onMouseOut="iOut('topnext'); iOut('bottomnext'); self.status=''; return true;" href="ws-j2x-4-7.html"><img alt="下页" border="0" src="../i/next.gif" name="topnext"></a></TD>
</TR>
</TABLE>
<table bgcolor="ffffff" cellspacing="0" cellpadding="2" border="0" height="400" width="100%">
<tr valign="bottom">
<a name="navskip"></a><td height="25" colspan="4"><img alt="4.循序渐进的 EJB 技术示例" src="imagemaster/titlebar4.jpg" border="0" height="25" width="562"></td>
</tr>
<tr>
<td bgcolor="ffffff" width="15"> </td><td bgcolor="ffffff" width="12"> </td><td valign="top" align="left" bgcolor="ffffff" width="*">
<p>
<br>
<table cellspacing="0" cellpadding="0" border="0">
<tr>
<td width="90%"><font size="4" face="Verdana, Arial, Helvetica"><b>XDoclet 和 EJB 技术：ejb.finder</b></font></td><td width="200" align="right"><font size="1" face="Verdana, Arial, Helvetica"><nobr> 第 6 页（共16 页）</nobr></font></td>
</tr>
</table>
<br>
<br>
</p>
<font size="2" face="Verdana, Arial, Helvetica">
<p>
为了定义实体 bean 的 <code>finder</code> 方法，您只需在类级别上添加 <code>ejb.finder</code> 标记，这个标记标识了 <code>finder</code> 方法特征符及其 EJB-QL 查询，如下所示：</p>
<p>
<pre>
<code style="font-family: Courier New, Courier, monospace; font-size: 12">
/**
*
* @ejb.finder
* signature="Dept findByDeptName(java.lang.String name)"
* unchecked="true"
* query="SELECT OBJECT(dept) FROM Dept dept where dept.name = ?1"
* result-type-mapping="Local"
*
* @ejb.finder
* signature="Collection findAll()"
* unchecked="true"
* query="SELECT OBJECT(dept) FROM Dept dept"
* result-type-mapping="Local"
*
*/
public abstract class DeptBean implements EntityBean {
</code>
</pre>
</p>
<p>
这将定义生成的 home 中的两个 <code>finder</code> 方法和 EJB 部署描述符中的 <code><query></code> 元素定义，如下所示：</p>
<p>
<pre>
<code style="font-family: Courier New, Courier, monospace; font-size: 12">
/*
* Generated by XDoclet - Do not edit!
*/
package ejb;
/**
* Local home interface for DeptBean.
*/
public interface DeptHome
extends javax.ejb.EJBLocalHome
{
...
public ejb.Dept findByDeptName(java.lang.String name)
throws javax.ejb.FinderException;
public java.util.Collection findAll()
throws javax.ejb.FinderException;
public ejb.Dept findByPrimaryKey(java.lang.Integer pk)
throws javax.ejb.FinderException;
}
</code>
</pre>
<pre>
<code style="font-family: Courier New, Courier, monospace; font-size: 12">
<entity >
<description>This entity bean represents a Department of Employees.</description>
<ejb-name>DeptBean</ejb-name>
<local-home>ejb.DeptHome</local-home>
<local>ejb.Dept</local>
...
<query>
<query-method>
<method-name>findByDeptName</method-name>
<method-params>
<method-param>java.lang.String</method-param>
</method-params>
</query-method>
<result-type-mapping>Local</result-type-mapping>
<ejb-ql>SELECT OBJECT(dept) FROM Dept dept where dept.name =?1
</ejb-ql>
</query>
<query>
<query-method>
<method-name>findAll</method-name>
<method-params>
</method-params>
</query-method>
<result-type-mapping>Local</result-type-mapping>
<ejb-ql>SELECT OBJECT(dept) FROM Dept dept</ejb-ql>
</query>
<!-- Write a file named ejb-finders-DeptBean.xml if you
want to define extra finders. -->
</entity>
</code>
</pre>
</p>
<br>
</font></td>
</tr>
</table>
<TABLE border="0" cellpadding="0" cellspacing="0" width="100%">
<TR>
<TD background="../i/sw-gold.gif"><a border="0" href="index.html" onMouseOver="iOver('topmain'); iOver('bottommain'); self.status=mainblurb; return true;" onMouseOut="iOut('topmain'); iOut('bottommain'); self.status=''; return true;"><img alt="主菜单" border="0" src="../i/main.gif" name="bottommain"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topsection'); iOver('bottomsection'); self.status=sectionblurb; return true;" onMouseOut="iOut('topsection'); iOut('bottomsection'); self.status=''; return true;" href="index4.html"><img alt="章节菜单" border="0" src="../i/section.gif" name="bottomsection"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topfeedback'); iOver('bottomfeedback'); self.status=feedbackblurb; return true;" onMouseOut="iOut('topfeedback'); iOut('bottomfeedback'); self.status=''; return true;" href="ws-j2x-6-3.html"><img alt="给出此教程的反馈意见" border="0" src="../i/feedback.gif" name="bottomfeedback"></a></TD><TD width="100%" background="../i/sw-gold.gif"><img src="../i/c.gif"></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topprevious'); iOver('bottomprevious'); self.status=previousblurb; return true;" onMouseOut="iOut('topprevious'); iOut('bottomprevious'); self.status=''; return true;" href="ws-j2x-4-5.html"><img alt="上页" border="0" src="../i/previous.gif" name="bottomprevious"></a></TD><TD background="../i/sw-gold.gif"><a border="0" onMouseOver="iOver('topnext'); iOver('bottomnext'); self.status=nextblurb; return true;" onMouseOut="iOut('topnext'); iOut('bottomnext'); self.status=''; return true;" href="ws-j2x-4-7.html"><img alt="下页" border="0" src="../i/next.gif" name="bottomnext"></a></TD>
</TR>
<TR>
<TD width="150" height="1" bgcolor="#000000" colspan="6"><IMG alt="" height="1" width="150" src="../i/c.gif"></TD>
</TR>
</TABLE>
<TABLE width="100%" cellpadding="0" cellspacing="0" border="0">
<TR>
<TD width="100%">
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td><img alt="" height="1" width="1" src="../i/c.gif"></td>
</tr>
<tr valign="top">
<td class="bbg" height="21"> <a class="mainlink" href="/developerWorks/cgi-bin/click.cgi?url=http://www-900.ibm.com/cn/ibm/index.shtml">关于 IBM</a><span class="divider"> | </span><a class="mainlink" href="/developerWorks/cgi-bin/click.cgi?url=http://www-900.ibm.com/cn/ibm/privacy/index.shtml">隐私条约</a><span class="divider"> | </span><a class="mainlink" href="/developerWorks/cgi-bin/click.cgi?url=http://www-900.ibm.com/cn/ibm/legal/index.shtml">法律条款</a><span class="divider"> | </span><a class="mainlink" href="/developerWorks/cgi-bin/click.cgi?url=http://www-900.ibm.com/cn/ibm/contact/index.shtml">联系 IBM</a></td>
</tr>
</table>
</TD>
</TR>
</TABLE>
<script src="//www.ibm.com/common/stats/stats.js" language="JavaScript1.2" type="text/javascript"></script>
<noscript>
<img border="0" alt="" height="1" width="1" src="//stats.www.ibm.com/rc/images/uc.GIF?R=noscript"></noscript>
</body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -