?? getsetprop.html
字號:
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<TITLE>Getting and Setting a Property of a Bean
(Java Developers Almanac Example)
</TITLE>
<META CONTENT="Patrick Chan" NAME="AUTHOR">
<META CONTENT="Code Examples from The Java Developers Almanac 1.4" NAME="DESCRIPTION">
<META CONTENT="Addison-Wesley/Patrick Chan" NAME="OWNER">
<META CONTENT="3/20/02" NAME="revision">
<STYLE TYPE="text/css">
<!-- BODY CODE {font-family: Courier, Monospace; font-size: 11pt} TABLE, BODY {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10pt} PRE {font-family: Courier, Monospace; font-size: 10pt} H3 {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 11pt} A.eglink {text-decoration: none} A:hover.eglink {text-decoration: underline} -->
</STYLE>
</HEAD>
<BODY>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD rowspan="3"><A HREF="/?l=ex"><IMG BORDER="0" ALIGN="BOTTOM" HSPACE="10" SRC="/egs/almanac14a.jpg"></A></TD><TD VALIGN="top"><font face="Times" size="6"><b>The Java Developers Almanac 1.4</b></font>
<br>
Order this book from <a href="/cgi-bin/scripts/redirect.pl?l=ex&url=http://www.amazon.com/exec/obidos/ASIN/0201752808/xeo">Amazon</a>.
</TD>
</TR>
<TR>
<TD align="right" valign="bottom">
<FORM method="get" action="/cgi-bin/search/find.pl">
<INPUT size="25" name="words" type="text"><INPUT value="Search" type="submit">
</FORM>
</TD>
</TR>
</TABLE>
<HR color="#6666cc">
<DIV ALIGN="LEFT">
<A HREF="/">Home</A>
>
<A HREF="../index.html">List of Packages</A>
>
<B><A HREF="../java.beans/pkg.html">java.beans</A></B><font color="#666666" SIZE="-2">
[12 examples]
</font>
</DIV><P>
<h3>
e6.
Getting and Setting a Property of a Bean</h3>
This example demonstrates how to get and set the value of a property
in a bean using <code>Expression</code> and <code>Statement</code>. The example gets
and sets three types of properties, an <code>Object</code>, a primitive type,
and an array. Both these classes use the name of the method that gets
or sets the property.
<pre>
Object o = new MyBean();
try {
// Get the value of prop1
Expression expr = new Expression(o, <font color="#0066ff"><i>"getProp1"</i></font>, new Object[0]);
expr.execute();
String s = (String)expr.getValue();
// Set the value of prop1
Statement stmt = new Statement(o, <font color="#0066ff"><i>"setProp1"</i></font>, new Object[]{<font color="#0066ff"><i>"new string"</i></font>});
stmt.execute();
// Get the value of prop2
expr = new Expression(o, <font color="#0066ff"><i>"getProp2"</i></font>, new Object[0]);
expr.execute();
int i = ((Integer)expr.getValue()).intValue();
// Set the value of prop2
stmt = new Statement(o, <font color="#0066ff"><i>"setProp2"</i></font>, new Object[]{<font color="#0066ff"><i>new Integer(123)</i></font>});
stmt.execute();
// Get the value of prop1
expr = new Expression(o, <font color="#0066ff"><i>"getProp3"</i></font>, new Object[0]);
expr.execute();
byte[] bytes = (byte[])expr.getValue();
// Set the value of prop1
stmt = new Statement(o, <font color="#0066ff"><i>"setProp3"</i></font>, new Object[]{<font color="#0066ff"><i>new byte[]{0x12, 0x23}</i></font>});
stmt.execute();
} catch (Exception e) {
}
public class <font color="#0066ff"><i>MyBean</i></font> {
// Property prop1
String prop1;
public String getProp1() {
return prop1;
}
public void setProp1(String s) {
prop1 = s;
}
// Property prop2
int prop2;
public int getProp2() {
return prop2;
}
public void setProp2(int i) {
prop2 = i;
}
// Property prop3
byte[] prop3;
public byte[] getProp3() {
return prop3;
}
public void setProp3(byte[] bytes) {
prop3 = bytes;
}
}
</pre>
<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td bgcolor="#6666cc" align="center"><font color="#ffffff">
Related Examples
</font></td>
</tr>
</table>
e1. <a class="eglink" href="BasicBean.html?l=rel">
The Quintessential Bean
</a>
<br>
e2. <a class="eglink" href="Bound.html?l=rel">
Implementing a Bound Property
</a>
<br>
e3. <a class="eglink" href="Constrain.html?l=rel">
Implementing a Constrained Property
</a>
<br>
e4. <a class="eglink" href="NewBean.html?l=rel">
Instantiating a Bean
</a>
<br>
e5. <a class="eglink" href="GetProps.html?l=rel">
Listing the Property Names of a Bean
</a>
<br>
<table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td align="left">
<br>
See also:
<a class="eglink" href="/egs/java.beans/pkg.html?l=rel#Events">
Events
</a>
<a class="eglink" href="/egs/java.beans/pkg.html?l=rel#Serialization">
Serialization
</a>
</td>
</tr>
</table>
<br>
<br>
<FONT FACE="Verdana, Arial, Helvetica, sans-serif" SIZE="0">
© 2002 Addison-Wesley.
</FONT>
</BODY>
</HTML>
?? 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
Ctrl + =
減小字號
Ctrl + -