Storing file contents in a Collection
Hi All,
Im trying to read a csv file, break the lines by comma, then store them and sort them.
I have the test code working from: http://java.sun.com/docs/books/tutorial/collections/interfaces/order.html
I am reading the file, but when I System.out.println() I keep getting the last line of the file only. Why is that?
try {
BufferedReader in = new BufferedReader(new FileReader("/Users/custodian/Desktop/list.csv"));
String line;
//Start reading the file while
while ((line = in.readLine()) != null) {
// System.out.println(line);
StringTokenizer st = new StringTokenizer(line, ",");
//Counting tokens while
while (st.hasMoreTokens()){
count++;
//System.out.println(st.nextToken());
fullname = st.nextToken();
StringTokenizer wsp = new StringTokenizer(fullname, " ");
//breaking full name apart while
while(wsp.hasMoreTokens()){
fname = wsp.nextToken();
lname = wsp.nextToken();
}
email = st.nextToken();
phone = st.nextToken();
streetaddress = st.nextToken();
city = st.nextToken();
state = st.nextToken();
zip = st.nextToken();
contactArray = new Contact(fname, lname, email, phone, streetaddress, city, state, zip);
System.out.println(contactArray.toString());
}
}
List <Contact> contacts = Arrays.asList(contactArray);
Collections.sort(contacts);
System.out.println(contacts);
[1505 byte] By [
iketurnaa] at [2007-11-27 6:36:20]
# 1
Well, in your code contactArray doesn't appear to be an array at all:
contactArray = new Contact(fname, lname, email, phone, streetaddress, city, state, zip);
And unless you're using an ancient JDK (pre 1.4) why not use String.split?
try {
BufferedReader in = new BufferedReader(new FileReader("/Users/custodian/Desktop/list.csv"));
List<Contact> contacts = new ArrayList<Contact>();
String line = null;
while ((line = in.readLine()) != null) {
String[] parts = line.split(",");
if (parts.length < 7) throw new RuntimeException("Invalid contact info");
String[] fullName = parts[0].split(" ");
if (fullName.length < 2) throw new RuntimeException("Invalid name");
contacts.add(new Contact(fullName[0], fullName[1], parts[1],
parts[2], parts[3], parts[4], parts[5], parts[6]));
}
Collections.sort(contacts);
System.out.println(contacts);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
dwga at 2007-7-12 18:03:54 >
# 3
Hi,
im trying to sort by state then write to another file:
I keep getting an error on Collections.sort(contacts, new StateComparator());
Collections.sort(contacts, new StateComparator());
try {
BufferedWriter out = new BufferedWriter(new FileWriter("state-sort.csv"));
//PrintWriter p = new PrintWriter(out);
out.write(firstLine + "\n");
Iterator it = contacts.listIterator();
while(it.hasNext()) {
Object o = it.next();
out.write(o.toString() + "\n");
}
out.flush();
out.close();
}catch(FileNotFoundException ee) {}
catch(IOException ioe) {}
Here is my Comparator
package mybeans;
class StateComparator implements Comparable
{
String state;
public String getState() { return state; }
public int compare(Object obj1, Object obj2)
{
if(obj1 == obj2)
return 0;
Contact c1 = (Contact) obj1;
Contact c2 = (Contact) obj2;
return c1.getState().compareTo(c2.getState());
}
public int compareTo(Object obj)
{
Contact c = (Contact) obj;
return (state).compareTo(c.state + c.state);
}
}
Any help appreciated.
# 4
Please use the code tags when posting code.
To answer your question:
Your StateComparator is implementing Comparable when it should be implementing Comparator. In my opinion it should look like this (assuming you are using JDK 1.5:
class StateComparator implements Comparator<Contact> {
@Override
public int compare(Contact c1, Contact c2) {
if (c1 == c2) return 0;
if (c1 == null && c2 == null) return 0;
if (c1 == null) return -1;
if (c2 == null) return 1;
// You might want to check for state's nullness aswell
return c1.getState().compareTo(c2.getState());
}
}
dwga at 2007-7-12 18:03:54 >
