KezvhLib/lib/com.google.com.collect/javadoc/com/google/common/base/Objects.html

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   7 Objects (Google Collections Library - snapshot-20080820 (ALPHA))
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  87 com.google.common.base</FONT>
  88 <BR>
  89 Class Objects</H2>
  90 <PRE>
  91 <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">java.lang.Object</A>
  92   <IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><B>com.google.common.base.Objects</B>
  93 </PRE>
  94 <HR>
  95 <DL>
  96 <DT><PRE>public final class <B>Objects</B><DT>extends <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A></DL>
  97 </PRE>
  98
  99 <P>
 100 Helper functions that can operate on any <code>Object</code>.
 101 <P>
 102
 103 <P>
 104 <DL>
 105 <DT><B>Author:</B></DT>
 106   <DD>Laurence Gonsalves</DD>
 107 </DL>
 108 <HR>
 109
 110 <P>
 111
 112 <!-- ========== METHOD SUMMARY =========== -->
 113
 114 <A NAME="method_summary"><!-- --></A>
 115 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
 116 <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
 117 <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
 118 <B>Method Summary</B></FONT></TH>
 119 </TR>
 120 <TR BGCOLOR="white" CLASS="TableRowColor">
 121 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
 122 <CODE>static&nbsp;boolean</CODE></FONT></TD>
 123 <TD><CODE><B><A HREF="../../../../com/google/common/base/Objects.html#equal(java.lang.Object, java.lang.Object)">equal</A></B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;a,
 124       <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;b)</CODE>
 125
 126 <BR>
 127 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Determines whether two possibly-null objects are equal.</TD>
 128 </TR>
 129 <TR BGCOLOR="white" CLASS="TableRowColor">
 130 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
 131 <CODE>static
 132 <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0" SUMMARY="">
 133 <TR ALIGN="right" VALIGN="">
 134 <TD NOWRAP><FONT SIZE="-1">
 135 <CODE>&lt;T&gt; T</CODE></FONT></TD>
 136 </TR>
 137 </TABLE>
 138 </CODE></FONT></TD>
 139 <TD><CODE><B><A HREF="../../../../com/google/common/base/Objects.html#firstNonNull(T, T)">firstNonNull</A></B>(T&nbsp;first,
 140              T&nbsp;second)</CODE>
 141
 142 <BR>
 143 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Returns the first of two given parameters that is not <code>null</code>, if
 144  either is, or otherwise throws a <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/NullPointerException.html" title="class or interface in java.lang"><CODE>NullPointerException</CODE></A>.</TD>
 145 </TR>
 146 <TR BGCOLOR="white" CLASS="TableRowColor">
 147 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
 148 <CODE>static&nbsp;int</CODE></FONT></TD>
 149 <TD><CODE><B><A HREF="../../../../com/google/common/base/Objects.html#hashCode(java.lang.Object...)">hashCode</A></B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>...&nbsp;objects)</CODE>
 150
 151 <BR>
 152 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Generates a hash code for multiple values.</TD>
 153 </TR>
 154 </TABLE>
 155 &nbsp;<A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A>
 156 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
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 158 <TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A></B></TH>
 159 </TR>
 160 <TR BGCOLOR="white" CLASS="TableRowColor">
 161 <TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#equals(java.lang.Object)" title="class or interface in java.lang">equals</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#toString()" title="class or interface in java.lang">toString</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#wait(long)" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD>
 162 </TR>
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 175 </TABLE>
 176
 177 <A NAME="equal(java.lang.Object, java.lang.Object)"><!-- --></A><H3>
 178 equal</H3>
 179 <PRE>
 180 public static boolean <B>equal</B>(<FONT SIZE="-1"><A HREF="../../../../com/google/common/base/Nullable.html" title="annotation in com.google.common.base">@Nullable</A></FONT>
 181                             <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;a,
 182                             <FONT SIZE="-1"><A HREF="../../../../com/google/common/base/Nullable.html" title="annotation in com.google.common.base">@Nullable</A></FONT>
 183                             <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;b)</PRE>
 184 <DL>
 185 <DD>Determines whether two possibly-null objects are equal. Returns:
 186
 187  <ul>
 188  <li><code>true</code> if <code>a</code> and <code>b</code> are both null.
 189  <li><code>true</code> if <code>a</code> and <code>b</code> are both non-null and they are
 190      equal according to <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#equals(java.lang.Object)" title="class or interface in java.lang"><CODE>Object.equals(Object)</CODE></A>.
 191  <li><code>false</code> in all other situations.
 192  </ul>
 193
 194  <p>This assumes that any non-null objects passed to this function conform
 195  to the <code>equals()</code> contract.
 196 <P>
 197 <DD><DL>
 198 </DL>
 199 </DD>
 200 </DL>
 201 <HR>
 202
 203 <A NAME="hashCode(java.lang.Object...)"><!-- --></A><H3>
 204 hashCode</H3>
 205 <PRE>
 206 public static int <B>hashCode</B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>...&nbsp;objects)</PRE>
 207 <DL>
 208 <DD>Generates a hash code for multiple values. The hash code is generated by
 209  calling <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Arrays.html#hashCode(java.lang.Object[])" title="class or interface in java.util"><CODE>Arrays.hashCode(Object[])</CODE></A>.
 210
 211  <p>This is useful for implementing <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html#hashCode()" title="class or interface in java.lang"><CODE>Object.hashCode()</CODE></A>. For example,
 212  in an object that has three properties, <code>x</code>, <code>y</code>, and
 213  <code>z</code>, one could write:
 214  <pre>
 215  public int hashCode() {
 216    return Objects.hashCode(getX(), getY(), getZ());
 217  }</pre>
 218
 219  <b>Warning</b>: When a single object is supplied, the returned hash code
 220  does not equal the hash code of that object.
 221 <P>
 222 <DD><DL>
 223 </DL>
 224 </DD>
 225 </DL>
 226 <HR>
 227
 228 <A NAME="firstNonNull(java.lang.Object,java.lang.Object)"><!-- --></A><A NAME="firstNonNull(T, T)"><!-- --></A><H3>
 229 firstNonNull</H3>
 230 <PRE>
 231 public static &lt;T&gt; T <B>firstNonNull</B>(<FONT SIZE="-1"><A HREF="../../../../com/google/common/base/Nullable.html" title="annotation in com.google.common.base">@Nullable</A></FONT>
 232                                  T&nbsp;first,
 233                                  <FONT SIZE="-1"><A HREF="../../../../com/google/common/base/Nullable.html" title="annotation in com.google.common.base">@Nullable</A></FONT>
 234                                  T&nbsp;second)</PRE>
 235 <DL>
 236 <DD>Returns the first of two given parameters that is not <code>null</code>, if
 237  either is, or otherwise throws a <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/NullPointerException.html" title="class or interface in java.lang"><CODE>NullPointerException</CODE></A>.
 238 <P>
 239 <DD><DL>
 240
 241 <DT><B>Returns:</B><DD><code>first</code> if <code>first</code> is not <code>null</code>, or
 242      <code>second</code> if <code>first</code> is <code>null</code> and <code>second</code> is
 243      not <code>null</code>
 244 <DT><B>Throws:</B>
 245 <DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/NullPointerException.html" title="class or interface in java.lang">NullPointerException</A></CODE> - if both <code>first</code> and <code>second</code> were
 246      <code>null</code></DL>
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