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;
}
}
在应用程序屏幕的某处：
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));
}
通过键从哈希表中获取值将很容易：
(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")
...