1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2 <!--NewPage--> 3 <HTML> 4 <HEAD> 5 <!-- Generated by javadoc (build 1.6.0-google-internal) on Mon Jan 04 20:47:56 PST 2010 --> 6 <TITLE> 7 Objects (Guava Libraries 2010.01.04) 8 </TITLE> 9 10 <META NAME="date" CONTENT="2010-01-04"> 11 12 <LINK REL ="stylesheet" TYPE="text/css" HREF="../../../../stylesheet.css" TITLE="Style"> 13 14 <SCRIPT type="text/javascript"> 15 function windowTitle() 16 { 17 if (location.href.indexOf('is-external=true') == -1) { 18 parent.document.title="Objects (Guava Libraries 2010.01.04)"; 19 } 20 } 21 </SCRIPT> 22 <NOSCRIPT> 23 </NOSCRIPT> 24 25 </HEAD> 26 27 <BODY BGCOLOR="white" onload="windowTitle();"> 28 <HR> 29 30 31 <!-- ========= START OF TOP NAVBAR ======= --> 32 <A NAME="navbar_top"><!-- --></A> 33 <A HREF="#skip-navbar_top" title="Skip navigation links"></A> 34 <TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""> 35 <TR> 36 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<!-- 65 if(window==top) { 66 document.writeln('<A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A>'); 67 } 68 //--> 69 </SCRIPT> 70 <NOSCRIPT> 71 <A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A> 72 </NOSCRIPT> 73 74 75 </FONT></TD> 76 </TR> 77 <TR> 78 <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 79 SUMMARY: <A HREF="#nested_class_summary">NESTED</A> | FIELD | CONSTR | <A HREF="#method_summary">METHOD</A></FONT></TD> 80 <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 81 DETAIL: FIELD | CONSTR | <A HREF="#method_detail">METHOD</A></FONT></TD> 82 </TR> 83 </TABLE> 84 <A NAME="skip-navbar_top"></A> 85 <!-- ========= END OF TOP NAVBAR ========= --> 86 87 <HR> 88 <!-- ======== START OF CLASS DATA ======== --> 89 <H2> 90 <FONT SIZE="-1"> 91 com.google.common.base</FONT> 92 <BR> 93 Class Objects</H2> 94 <PRE> 95 <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</A> 96 <IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><B>com.google.common.base.Objects</B> 97 </PRE> 98 <HR> 99 <DL> 100 <DT><PRE>public final class <B>Objects</B><DT>extends <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></DL> 101 </PRE> 102 103 <P> 104 Helper functions that can operate on any <code>Object</code>. 105 <P> 106 107 <P> 108 <DL> 109 <DT><B>Since:</B></DT> 110 <DD>2010.01.04 <b>stable</b> (imported from Google Collections Library)</DD> 111 <DT><B>Author:</B></DT> 112 <DD>Laurence Gonsalves</DD> 113 </DL> 114 <HR> 115 116 <P> 117 <!-- ======== NESTED CLASS SUMMARY ======== --> 118 119 <A NAME="nested_class_summary"><!-- --></A> 120 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> 121 <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> 122 <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"> 123 <B>Nested Class Summary</B></FONT></TH> 124 </TR> 125 <TR BGCOLOR="white" CLASS="TableRowColor"> 126 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> 127 <CODE>static class</CODE></FONT></TD> 128 <TD><CODE><B><A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base">Objects.ToStringHelper</A></B></CODE> 129 130 <BR> 131 Support class for <A HREF="../../../../com/google/common/base/Objects.html#toStringHelper(java.lang.Object)"><CODE>toStringHelper(java.lang.Object)</CODE></A>.</TD> 132 </TR> 133 </TABLE> 134 135 <!-- ========== METHOD SUMMARY =========== --> 136 137 <A NAME="method_summary"><!-- --></A> 138 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> 139 <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> 140 <TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"> 141 <B>Method Summary</B></FONT></TH> 142 </TR> 143 <TR BGCOLOR="white" CLASS="TableRowColor"> 144 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> 145 <CODE>static boolean</CODE></FONT></TD> 146 <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?is-external=true" title="class or interface in java.lang">Object</A> a, 147 <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> b)</CODE> 148 149 <BR> 150 Determines whether two possibly-null objects are equal.</TD> 151 </TR> 152 <TR BGCOLOR="white" CLASS="TableRowColor"> 153 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> 154 <CODE>static int</CODE></FONT></TD> 155 <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?is-external=true" title="class or interface in java.lang">Object</A>... objects)</CODE> 156 157 <BR> 158 Generates a hash code for multiple values.</TD> 159 </TR> 160 <TR BGCOLOR="white" CLASS="TableRowColor"> 161 <TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"> 162 <CODE>static <A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base">Objects.ToStringHelper</A></CODE></FONT></TD> 163 <TD><CODE><B><A HREF="../../../../com/google/common/base/Objects.html#toStringHelper(java.lang.Object)">toStringHelper</A></B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> object)</CODE> 164 165 <BR> 166 Creates an instance of <A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base"><CODE>Objects.ToStringHelper</CODE></A>.</TD> 167 </TR> 168 </TABLE> 169 <A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A> 170 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> 171 <TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"> 172 <TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></B></TH> 173 </TR> 174 <TR BGCOLOR="white" CLASS="TableRowColor"> 175 <TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#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?is-external=true#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang">toString</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#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?is-external=true#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD> 176 </TR> 177 </TABLE> 178 179 <P> 180 181 <!-- ============ METHOD DETAIL ========== --> 182 183 <A NAME="method_detail"><!-- --></A> 184 <TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> 185 <TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> 186 <TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2"> 187 <B>Method Detail</B></FONT></TH> 188 </TR> 189 </TABLE> 190 191 <A NAME="equal(java.lang.Object, java.lang.Object)"><!-- --></A><H3> 192 equal</H3> 193 <PRE> 194 public static boolean <B>equal</B>(<FONT SIZE="-1"><A HREF="http://jsr-305.googlecode.com/svn/trunk/javadoc/javax/annotation/Nullable.html?is-external=true" title="class or interface in javax.annotation">@Nullable</A></FONT> 195 <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> a, 196 <FONT SIZE="-1"><A HREF="http://jsr-305.googlecode.com/svn/trunk/javadoc/javax/annotation/Nullable.html?is-external=true" title="class or interface in javax.annotation">@Nullable</A></FONT> 197 <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> b)</PRE> 198 <DL> 199 <DD>Determines whether two possibly-null objects are equal. Returns: 200 201 <ul> 202 <li><code>true</code> if <code>a</code> and <code>b</code> are both null. 203 <li><code>true</code> if <code>a</code> and <code>b</code> are both non-null and they are 204 equal according to <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang"><CODE>Object.equals(Object)</CODE></A>. 205 <li><code>false</code> in all other situations. 206 </ul> 207 208 <p>This assumes that any non-null objects passed to this function conform 209 to the <code>equals()</code> contract. 210 <P> 211 <DD><DL> 212 </DL> 213 </DD> 214 </DL> 215 <HR> 216 217 <A NAME="hashCode(java.lang.Object...)"><!-- --></A><H3> 218 hashCode</H3> 219 <PRE> 220 public static int <B>hashCode</B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A>... objects)</PRE> 221 <DL> 222 <DD>Generates a hash code for multiple values. The hash code is generated by 223 calling <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Arrays.html?is-external=true#hashCode(java.lang.Object[])" title="class or interface in java.util"><CODE>Arrays.hashCode(Object[])</CODE></A>. 224 225 <p>This is useful for implementing <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang"><CODE>Object.hashCode()</CODE></A>. For example, 226 in an object that has three properties, <code>x</code>, <code>y</code>, and 227 <code>z</code>, one could write: 228 <pre> 229 public int hashCode() { 230 return Objects.hashCode(getX(), getY(), getZ()); 231 }</pre> 232 233 <b>Warning</b>: When a single object is supplied, the returned hash code 234 does not equal the hash code of that object. 235 <P> 236 <DD><DL> 237 </DL> 238 </DD> 239 </DL> 240 <HR> 241 242 <A NAME="toStringHelper(java.lang.Object)"><!-- --></A><H3> 243 toStringHelper</H3> 244 <PRE> 245 public static <A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base">Objects.ToStringHelper</A> <B>toStringHelper</B>(<A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A> object)</PRE> 246 <DL> 247 <DD>Creates an instance of <A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base"><CODE>Objects.ToStringHelper</CODE></A>. 248 249 <p>This is helpful for implementing <A HREF="http://java.sun.com/javase/6/docs/api/java/lang/Object.html?is-external=true#toString()" title="class or interface in java.lang"><CODE>Object.toString()</CODE></A>. For 250 example, in an object that contains two member variables, <code>x</code>, 251 and <code>y</code>, one could write:<pre> <tt> 252 public class ClassName { 253 public String toString() { 254 return Objects.toStringHelper(this) 255 .add("x", x) 256 .add("y", y) 257 .toString(); 258 } 259 }</tt> 260 </pre> 261 262 Assuming the values of <code>x</code> and <code>y</code> are 1 and 2, 263 this code snippet returns the string <tt>"ClassName{x=1, y=2}"</tt>. 264 <P> 265 <DD><DL> 266 <DT><B>Since:</B></DT> 267 <DD>2010.01.04 <b>tentative</b></DD> 268 </DL> 269 </DD> 270 </DL> 271 <!-- ========= END OF CLASS DATA ========= --> 272 <HR> 273 274 275 <!-- ======= START OF BOTTOM NAVBAR ====== --> 276 <A NAME="navbar_bottom"><!-- --></A> 277 <A HREF="#skip-navbar_bottom" title="Skip navigation links"></A> 278 <TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""> 279 <TR> 280 <TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> 281 <A NAME="navbar_bottom_firstrow"><!-- --></A> 282 <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> 283 <TR ALIGN="center" VALIGN="top"> 284 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> 285 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> 286 <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> 287 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/Objects.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> 288 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> 289 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> 290 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> 291 <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> 292 </TR> 293 </TABLE> 294 </TD> 295 <TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM> 296 </EM> 297 </TD> 298 </TR> 299 300 <TR> 301 <TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 302 <A HREF="../../../../com/google/common/base/Joiner.MapJoiner.html" title="class in com.google.common.base"><B>PREV CLASS</B></A> 303 <A HREF="../../../../com/google/common/base/Objects.ToStringHelper.html" title="class in com.google.common.base"><B>NEXT CLASS</B></A></FONT></TD> 304 <TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> 305 <A HREF="../../../../index.html?com/google/common/base/Objects.html" target="_top"><B>FRAMES</B></A> 306 <A HREF="Objects.html" target="_top"><B>NO FRAMES</B></A> 307 <SCRIPT type="text/javascript"> 308 <!-- 309 if(window==top) { 310 document.writeln('<A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A>'); 311 } 312 //--> 313 </SCRIPT> 314 <NOSCRIPT> 315 <A HREF="../../../../allclasses-noframe.html"><B>All Classes</B></A> 316 </NOSCRIPT> 317 318 319 </FONT></TD> 320 </TR> 321 <TR> 322 <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 323 SUMMARY: <A HREF="#nested_class_summary">NESTED</A> | FIELD | CONSTR | <A HREF="#method_summary">METHOD</A></FONT></TD> 324 <TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> 325 DETAIL: FIELD | CONSTR | <A HREF="#method_detail">METHOD</A></FONT></TD> 326 </TR> 327 </TABLE> 328 <A NAME="skip-navbar_bottom"></A> 329 <!-- ======== END OF BOTTOM NAVBAR ======= --> 330 331 <HR> 332 333 </BODY> 334 </HTML> 335
