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<html><head><title>VM Spec </title></head><body BGCOLOR=#eeeeff text=#000000 LINK=#0000ff VLINK=#000077 ALINK=#ff0000> <a href="VMSpecTOC.doc.html">Contents</a> | <a href="Instructions2.doc112.html">Prev</a> | <a href="Instructions2.doc114.html">Next</a> | <a href="Mnemonics.doc.html">Index</a><hr><br> <a name="invokevirtual"></a><h2>invokevirtual</h2><a name="68968"></a>The <i>objectref</i> must be of type <code>reference</code>. The <i>index</i> is used as an index into the method table of the class of the type of <i>objectref</i>. If the <i>objectref</i> is an array type, then the method table of class <code>Object</code> is used. The table entry at that index includes a direct reference to the method's code and its modifier information (see <a href="ClassFile.doc.html#12725">Table 4.4, "Method access and modifier flags"</a>).<p><a name="68969"></a>The <i>objectref</i> must be followed on the operand stack by <i>nargs </i>- 1 words of arguments, where the number of words of arguments and the type and order of the values they represent must be consistent with the descriptor of the selected instance method.<p><a name="138096"></a>If the method is <code>synchronized</code>, the monitor associated with <i>objectref</i> is acquired.<p><a name="135976"></a>If the method is not <code>native</code>, the <i>nargs </i>- 1 words of arguments and <i>objectref</i> are popped from the operand stack. A new stack frame is created for the method being invoked, and <i>objectref</i> and the words of arguments are made the values of its first <i>nargs</i> local variables, with <i>objectref</i> in local variable <i>0</i>, <i>arg1</i> in local variable <i>1</i>, and so on. The new stack frame is then made current, and the Java Virtual Machine <code>pc</code> is set to the opcode of the first instruction of the method to be invoked. Execution continues with the first instruction of the method.<p><a name="138113"></a>If the method is <code>native</code> and the platform-dependent code that implements it has not yet been loaded and linked into the Java Virtual Machine, that is done. The <i>nargs </i>- 1 words of arguments and <i>objectref</i> are popped from the operand stack; the code that implements the method is invoked in an implementation-dependent manner.<p><a name="invokevirtual.Linking"></a><b>Linking Exceptions</b><br><a name="117277"></a>During resolution of the <code>CONSTANT_Methodref</code> constant pool item, any of the exceptions documented in <a href="ConstantPool.doc.html#49425">§5.2</a> can be thrown.<p><hr><!-- This inserts footnotes--><p><a href="VMSpecTOC.doc.html">Contents</a> | <a href="Instructions2.doc112.html">Prev</a> | <a href="Instructions2.doc114.html">Next</a> | <a href="Mnemonics.doc.html">Index</a><p><font size=-1>Java Virtual Machine Specification (HTML generated by dkramer on February 25, 1997)<br><i><a href="Copyright.doc.html">Copyright © 1996 Sun Microsystems, Inc.</a>All rights reserved</i><br>Please send any comments or corrections to <a href="mailto:doug.kramer@sun.com">doug.kramer@sun.com</a></font></body></html>⌨️ 快捷键说明
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