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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc (build 1.5.0_14) on Mon Jan 28 05:47:04 PST 2008 --><TITLE>ManyToMany (Java EE 5)</TITLE><META NAME="keywords" CONTENT="javax.persistence.ManyToMany class"><LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"><SCRIPT type="text/javascript">function windowTitle(){ parent.document.title="ManyToMany (Java EE 5)";}</SCRIPT><NOSCRIPT></NOSCRIPT></HEAD><BODY BGCOLOR="white" onload="windowTitle();"><!-- ========= START OF TOP NAVBAR ======= --><A NAME="navbar_top"><!-- --></A><A HREF="#skip-navbar_top" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/persistence/LockModeType.html" title="enum in javax.persistence"><B>PREV CLASS</B></A> <A HREF="../../javax/persistence/ManyToOne.html" title="annotation in javax.persistence"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html?javax/persistence/ManyToMany.html" target="_top"><B>FRAMES</B></A> <A HREF="ManyToMany.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: REQUIRED | <A HREF="#annotation_type_optional_element_summary">OPTIONAL</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: <A HREF="#annotation_type_element_detail">ELEMENT</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_top"></A><!-- ========= END OF TOP NAVBAR ========= --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">javax.persistence</FONT><BR>Annotation Type ManyToMany</H2><HR><DL><DT><PRE><FONT SIZE="-1"><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Target.html" title="class or interface in java.lang.annotation">@Target</A>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Target.html#value()" title="class or interface in java.lang.annotation">value</A>={<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/ElementType.html#METHOD" title="class or interface in java.lang.annotation">METHOD</A>,<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/ElementType.html#FIELD" title="class or interface in java.lang.annotation">FIELD</A>})<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Retention.html" title="class or interface in java.lang.annotation">@Retention</A>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Retention.html#value()" title="class or interface in java.lang.annotation">value</A>=<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/RetentionPolicy.html#RUNTIME" title="class or interface in java.lang.annotation">RUNTIME</A>)</FONT>public @interface <B>ManyToMany</B></DL></PRE><P>Defines a many-valued association with many-to-many multiplicity. If the Collection is defined using generics to specify the element type, the associated target entity class does not need to be specified; otherwise it must be specified. <p> Every many-to-many association has two sides, the owning side and the non-owning, or inverse, side. The join table is specified on the owning side. If the association is bidirectional, either side may be designated as the owning side. <p> The same annotation elements for the <A HREF="../../javax/persistence/OneToMany.html" title="annotation in javax.persistence"><CODE>OneToMany</CODE></A> annotation apply to the <code>ManyToMany</code> annotation. <pre> Example 1: In Customer class: @ManyToMany @JoinTable(name="CUST_PHONES") public Set<PhoneNumber> getPhones() { return phones; } In PhoneNumber class: @ManyToMany(mappedBy="phones") public Set<Customer> getCustomers() { return customers; } Example 2: In Customer class: @ManyToMany(targetEntity=com.acme.PhoneNumber.class) public Set getPhones() { return phones; } In PhoneNumber class: @ManyToMany(targetEntity=com.acme.Customer.class, mappedBy="phones") public Set getCustomers() { return customers; } Example 3: In Customer class: @ManyToMany @JoinTable(name="CUST_PHONE", joinColumns= @JoinColumn(name="CUST_ID", referencedColumnName="ID"), inverseJoinColumns= @JoinColumn(name="PHONE_ID", referencedColumnName="ID") ) public Set<PhoneNumber> getPhones() { return phones; } In PhoneNumberClass: @ManyToMany(mappedBy="phones") public Set<Customer> getCustomers() { return customers; } </pre><P><P><DL><DT><B>Since:</B></DT> <DD>Java Persistence 1.0</DD></DL><HR><P><!-- =========== ANNOTATION TYPE OPTIONAL MEMBER SUMMARY =========== --><A NAME="annotation_type_optional_element_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Optional Element Summary</B></FONT></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../javax/persistence/CascadeType.html" title="enum in javax.persistence">CascadeType</A>[]</CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/ManyToMany.html#cascade()">cascade</A></B></CODE><BR> (Optional) The operations that must be cascaded to the target of the association.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../javax/persistence/FetchType.html" title="enum in javax.persistence">FetchType</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/ManyToMany.html#fetch()">fetch</A></B></CODE><BR> (Optional) Whether the association should be lazily loaded or must be eagerly fetched.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/ManyToMany.html#mappedBy()">mappedBy</A></B></CODE><BR> The field that owns the relationship.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Class.html" title="class or interface in java.lang">Class</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/ManyToMany.html#targetEntity()">targetEntity</A></B></CODE><BR> (Optional) The entity class that is the target of the association.</TD></TR></TABLE> <P><A NAME="targetEntity()"><!-- --></A><H3>targetEntity</H3><PRE>public abstract <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Class.html" title="class or interface in java.lang">Class</A> <B>targetEntity</B></PRE><DL><DD>(Optional) The entity class that is the target of the association. Optional only if the collection property is defined using Java generics. Must be specified otherwise. <p> Defaults to the parameterized type of the collection when defined using generics.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>void.class</DD></DL></DL><HR><A NAME="cascade()"><!-- --></A><H3>cascade</H3><PRE>public abstract <A HREF="../../javax/persistence/CascadeType.html" title="enum in javax.persistence">CascadeType</A>[] <B>cascade</B></PRE><DL><DD>(Optional) The operations that must be cascaded to the target of the association. <p> Defaults to no operations being cascaded.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>{}</DD></DL></DL><HR><A NAME="fetch()"><!-- --></A><H3>fetch</H3><PRE>public abstract <A HREF="../../javax/persistence/FetchType.html" title="enum in javax.persistence">FetchType</A> <B>fetch</B></PRE><DL><DD>(Optional) Whether the association should be lazily loaded or must be eagerly fetched. The <A HREF="../../javax/persistence/FetchType.html#EAGER"><CODE>EAGER</CODE></A> strategy is a requirement on the persistenceprovider runtime that the associatedentities must be eagerly fetched. The <A HREF="../../javax/persistence/FetchType.html#LAZY"><CODE>LAZY</CODE></A> strategy is a hint to the persistence provider runtime.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>LAZY</DD></DL></DL><HR><A NAME="mappedBy()"><!-- --></A><H3>mappedBy</H3><PRE>public abstract <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>mappedBy</B></PRE><DL><DD>The field that owns the relationship. Required unless the relationship is unidirectional.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>""</DD></DL></DL><!-- ========= END OF CLASS DATA ========= --><HR><!-- ======= START OF BOTTOM NAVBAR ====== --><A NAME="navbar_bottom"><!-- --></A><A HREF="#skip-navbar_bottom" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_bottom_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/persistence/LockModeType.html" title="enum in javax.persistence"><B>PREV CLASS</B></A> <A HREF="../../javax/persistence/ManyToOne.html" title="annotation in javax.persistence"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html?javax/persistence/ManyToMany.html" target="_top"><B>FRAMES</B></A> <A HREF="ManyToMany.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: REQUIRED | <A HREF="#annotation_type_optional_element_summary">OPTIONAL</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: <A HREF="#annotation_type_element_detail">ELEMENT</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_bottom"></A><!-- ======== END OF BOTTOM NAVBAR ======= --><HR><font size="-1"><a href="http://java.sun.com/webapps/bugreport">Submit a bug or feature</a> <p>Copyright 2007 Sun Microsystems, Inc. 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