title: JUNG - How to get the exact vertex in Graph?
body: <p>I have to create a graph with its self-defined node type and the nodes &amp; connections are read from a txt file one by one.</p>
  
  <p>The file format is like this: startNode attibutes endNode.</p>
  
  <p>Every time I read one line, I created 2 node objects: startNode &amp; endNode. and add edge between them..</p>
  
  <p>However, the startNode may exist in several lines..</p>
  
  <p>e.g. V1 ... V2 ; V1 ... V3</p>
  
  <p>Therefore, I have to check whether my graph has contained the node before I add edges..and I should use the vertex in graphs instead of the node newly created..</p>
  
  <p>Does jung have any built-in method to solve this problem?
  Or any suggestions?</p>