The code works, but I can't get it to read the file. Can you tell me what I need to do to get the GUI to load the text file and run the program?
I have the input.txt file saved on My Desktop
Graph.java
import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.LinkedList; import java.util.Stack; import java.util.StringTokenizer;
//user defined exception class to throw exception for cycle detected or unknown class name class GraphException extends Exception { public GraphException(String s) { super(s); } } public class Graph { //This is an arraylist of list of integers. So each element in the array is set of integers //adjacent to the vertext. The mapping from vertext number to vertex name is stored in the //vertexMap. for example if 0 =classA 1=classB 2=classC in vertexmap and B and C are dependent on A, //vertices will have 0[1 2] ArrayList> vertices; HashMap vertexMap; private Graph() { vertices=new ArrayList>(); vertexMap=new HashMap(); } //adds a edge in graph. If source or destination was not yet in graph , they are added to vertices list //and assigned a id based on how many vertices were already in the list. The adjacency list of the //source node is updated with the destination private void addEdge(T source,T destination ) { Integer id1=vertexMap.get(source),id2=vertexMap.get(destination); LinkedList adjacent; if(id1==null) { id1=vertices.size(); vertexMap.put(source, id1); vertices.add(adjacent=new LinkedList()); } else adjacent=vertices.get(id1); if(id2==null) { id2=vertices.size(); vertexMap.put(destination, id2); vertices.add(new LinkedList()); } adjacent.add(id2); } //calls the depth_first_search() and then pops out th e stack that was populated in the function public String topologicalOrder(T vertex) throws GraphException { ArrayList visited=new ArrayList(),finished=new ArrayList() ; Stack stack=new Stack(); Integer id=vertexMap.get(vertex); if(id==null) throw new GraphException("Vertex "+vertex+" not found in graph!"); depthFirstSearch(id, visited, finished, stack); StringBuffer str=new StringBuffer(); while(!stack.isEmpty()) { str.append(getKeyFromValue(stack.pop())+" "); } return str.toString(); } //returns the key for the given value from vertexMap. Suppose you pass 1, then if 1 is a value //for some key, it returns the key i.e the class name associated with value 1 private T getKeyFromValue(int value) { for (T o : vertexMap.keySet()) { if (vertexMap.get(o).equals(value)) { return o; } } return null; } //implements the algorithm for topological order private void depthFirstSearch(int start,ArrayList visited,ArrayList finished,Stack stack) throws GraphException { if(visited.contains(start)) throw new GraphException("Cycle detected for "+getKeyFromValue(start)); else if(finished.contains(start)) { return ; } else { visited.add(start); LinkedList adj=vertices.get(start); for(int i=0;i initialize(String filename) throws IOException { Graph graph=new Graph(); File file = new File(filename); FileReader fileReader = new FileReader(file); BufferedReader bufferedReader = new BufferedReader(fileReader); String line; while((line=bufferedReader.readLine())!=null) {
//break up the dependency string into token using space delimmiter StringTokenizer tokenizer=new StringTokenizer(line, " "); String src=tokenizer.nextToken(); while(tokenizer.hasMoreTokens()) { //add an edge for each name appearing in the list graph.addEdge(src,tokenizer.nextToken()); } } bufferedReader.close(); return graph; } //function to display the graph, used for testing purpose public void display() { for (T name: vertexMap.keySet()){
System.out.println(vertexMap.get(name)+"="+name); } LinkedList list; for(int i=0;i g=Graph.initialize(filename); g.display(); System.out.println(g.topologicalOrder("ClassA")); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (GraphException e) { // TODO Auto-generated catch block e.printStackTrace(); } }*/ }
GraphUI.java
import java.awt.BorderLayout; import java.awt.Container; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.GridLayout; import java.awt.Panel; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.IOException;
import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextField; //Builds a UI with textfields for accepting filename to load and class name to find topological order. public class GraphUI extends JFrame { JTextField txtFileName,txtClassName,txtOrder; JButton build,order; Graph graph; public GraphUI() { init(); } public void init() { //creates the different labels , textfields and butttons and adds them setTitle("Class Dependency Graph"); setSize(500, 150); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Container pane; pane=getContentPane(); pane.setLayout(new BoxLayout(pane,BoxLayout.Y_AXIS)); JPanel panel1=new JPanel(); panel1.setLayout(new GridLayout(2, 3)); panel1.add(new JLabel("Input file name:")); panel1.add(txtFileName=new JTextField()); panel1.add(build=new JButton("Build Directed Graph")); //panel1.setLayout(new BoxLayout(panel1,BoxLayout.X_AXIS )); panel1.add(new JLabel("Class to recompile:")); panel1.add(txtClassName=new JTextField()); panel1.add(order=new JButton("Topological order")); pane.add(panel1); JPanel panel2=new JPanel(); panel2.setLayout(new GridLayout(1, 1)); panel2.add(txtOrder=new JTextField(" ")); pane.add(panel2); final JFrame uiwindow=this; build.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { try { graph=Graph.initialize(txtFileName.getText()); JOptionPane.showMessageDialog(uiwindow, "Graph built successfully!"); } catch (IOException e1) { JOptionPane.showMessageDialog(uiwindow, "File could not load!"); } } }); order.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { try { txtOrder.setText(graph.topologicalOrder(txtClassName.getText())); } catch (GraphException e1) { JOptionPane.showMessageDialog(uiwindow, e1.getMessage()); } } }); setVisible(true); } public static void main(String[] args) { GraphUI uiApp = new GraphUI(); }
}
input.txt
ClassA ClassC ClassE ClassB ClassD ClassG ClassE ClassB ClassF ClassH ClassI ClassC
Class Dependency Graph Input file name: nput.txt Build Directed Graph Class to recompile: Topological order
