Parsing data from txt file in J2ME

Answer 1

package filereader;

import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.Vector;

public class FileReader {
    String locationSection;
    String edgeSection;
    Vector locations;
    Vector edges;

    public FileReader(String fileName) {
     // read the contents into the string
     InputStream is = getClass().getResourceAsStream(fileName);
     StringBuffer sb = new StringBuffer();
     int ch;
     try {
      while ((ch = is.read()) != -1) {
       sb.append((char) ch);
      }
     } catch (IOException e2) {
      e2.printStackTrace();
     }
     try {
      is.close();
     } catch (IOException e) {
      e.printStackTrace();
     }
     String text = sb.toString();

     // separate locations and edges
     String separator = "_________________________";

     // read location section, without last end-of-line char
     int endLocationSection = text.indexOf(separator) - 1;
     locationSection = text.substring(0, endLocationSection);

     // read edges section, without end-of-line char after separator
     int startEdgeSection = endLocationSection + separator.length() + 3;
     edgeSection = text.substring(startEdgeSection, text.length());

     // parse locations and edges
     locations = getLocationsVector(locationSection);
     edges = getEdgesVector(edgeSection);
    }

    // parse locations section
    public Vector getLocationsVector(String section) {
     Vector result = new Vector();
     int startLine = 0;
     int endLine = section.indexOf('\n');
     while (endLine != -1) {
      String line = section.substring(startLine, endLine);
      result.addElement(parseLocationsLine(line, ';'));
      startLine = endLine + 1;
      if (endLine == section.length() - 1)
       break;
      endLine = section.indexOf('\n', startLine);
      // if no new line found, read to the end of string
      endLine = (-1 == endLine) ? section.length() - 1 : endLine;
     }
     return result;
    }

    // parse edges section
    public Vector getEdgesVector(String section) {
     Vector result = new Vector();
     int startLine = 0;
     int endLine = section.indexOf('\n');
     while (endLine != -1) {
      String line = section.substring(startLine, endLine - 1);
      result.addElement(parseEdgesLine(line, ';'));
      startLine = endLine + 1;
      if (endLine == section.length() + 1)
       break;
      endLine = section.indexOf('\n', startLine);
      // if no new line found, read to the end of string
      endLine = (-1 == endLine) ? section.length() + 1 : endLine;
     }
     return result;
    }

    // parse locations line
    public Hashtable parseLocationsLine(String value, char splitBy) {
     Hashtable result = new Hashtable();
     int xCEnd = value.indexOf(splitBy);
     int yCEnd = value.indexOf(splitBy, xCEnd + 1);
     result.put("x", value.substring(0, xCEnd));
     result.put("y", value.substring(xCEnd + 1, yCEnd));
     result.put("location", value.substring(yCEnd + 1, 
      value.length() - 1));
     return result;
    }

    // parse edges line
    public Hashtable parseEdgesLine(String value, char splitBy) {
     Hashtable result = new Hashtable();
     int snEnd = value.indexOf(splitBy);
     result.put("startnode", value.substring(0, snEnd));
     int n = 1;
     int start = snEnd + 1;
     int enEnd = value.indexOf(splitBy, snEnd + 1);
     int dstEnd = value.indexOf(splitBy, enEnd + 1);
     while (enEnd != -1 && dstEnd != -1) {
      result.put("endnode" + String.valueOf(n), 
        value.substring(start, enEnd));
      result.put("distance" + String.valueOf(n), value.substring(
        enEnd + 1, dstEnd));
      start = dstEnd + 1;
      enEnd = value.indexOf(splitBy, start);
      if (dstEnd == value.length())
       break;
      dstEnd = value.indexOf(splitBy, enEnd + 1);
      // if last endnode-distance pair, read to the end of line
      dstEnd = (-1 == dstEnd) ? value.length() : dstEnd;
      n++;
     }
     return result;
    }

    // getters for locations and edges
    public Vector getLocations() {
     return locations;
    }

    public Vector getEdges() {
     return edges;
    }

}

and somewhere in application screen:

fr = new FileReader("/map.txt");
Vector vct1 = fr.getLocations();
for (int i = 0; i < vct1.size(); i++) {
 Hashtable location = (Hashtable) vct1.elementAt(i);
 Enumeration en = location.keys();
 String fv = "";
 while (en.hasMoreElements()) {
  String key = (String) en.nextElement();
  String value = (String)location.get(key);
  fv = fv + value + "-";
 }
 this.add(new LabelField(fv));  

}
Vector vct2 = fr.getEdges();
for (int i = 0; i < vct2.size(); i++) {
 Hashtable location = (Hashtable) vct2.elementAt(i);
 Enumeration en = location.keys();
 String fv = "";
 while (en.hasMoreElements()) {
  String key = (String) en.nextElement();
  String value = (String)location.get(key);
  fv = fv + value + "-";
 }
 this.add(new LabelField(fv));  

}

it will be easy to get values from hashtable by keys:
(String)location.get("x")
(String)location.get("y")
(String)location.get("location")
(String)edge.get("startnode")
(String)edge.get("endnode1")
(String)edge.get("distance1")
(String)edge.get("endnode2")
(String)edge.get("distance2")
...