title: What Java compilers use the jsr instruction, and what for?
body: <p>The Java bytecode language has the JSR instruction.</p>
  
  <p>None of the code I've compiled with the Java 7 compiler uses this instruction.</p>
  
  <p>However, sometimes Java binaries I've downloaded do use it, although rarely.</p>
  
  <p>I'd be interested to know what compilers do use the instruction, and what Java code constructs would cause them to use it.</p>
  
  <p><strong>Edit</strong> this is not a duplicate as it refers to the JSR bytecode instruction and not a Java Specification Request</p>