I'm trying to set items from a method called FootballClub and so far it's fine.
but then I created an arrayList from it and I somehow can't find a way to store this information into a JTable.
The problem is that i cant find a way to set a fixed number of rows
Here is my code:
Class StartLeague:
import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;
public class startLeague implements LeagueManager{
//setting the frame and other components to appear
public startLeague(){
JButton createTeam = new JButton("Create Team");
JButton deleteTeam = new JButton("Delete Team");
JFrame frame = new JFrame("Premier League System");
JPanel panel = new JPanel();
frame.setSize(1280, 800);
frame.setVisible(true);
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
String col[] = {"Pos","Team","P", "W", "L", "D", "MP", "GF", "GA", "GD"};
panel.setLayout(new GridLayout(20, 20));
panel.add(createTeam);
panel.add(deleteTeam);
panel.add(new JLabel(""));
//JLabels to fill the space
}
}
FootBall Club Class:
import java.util.ArrayList;
public class FootballClub extends SportsClub{
FootballClub(int position, String name, int points, int wins, int defeats, int draws, int totalMatches, int goalF, int goalA, int goalD){
this.position = position;
this.name = name;
this.points = points;
this.wins = wins;
this.defeats = defeats;
this.draws = draws;
this.totalMatches = totalMatches;
this.goalF = goalF;
this.goalA = goalA;
this.goalD = goalD;
}
The SportsClub Class(abstract):
abstract class SportsClub {
int position;
String name;
int points;
int wins;
int defeats;
int draws;
int totalMatches;
int goalF;
int goalA;
int goalD;
}
And finally, LeagueManager, which is an interface:
import java.util.ArrayList;
public interface LeagueManager {
ArrayList<FootballClub> originalLeagueTable = new ArrayList<FootballClub>();
FootballClub arsenal = new FootballClub(1, "Arsenal", 35, 11, 2, 2, 15, 30, 11, 19);
FootballClub liverpool = new FootballClub(2, "Liverpool", 30, 9, 3, 3, 15, 34, 18, 16);
FootballClub chelsea = new FootballClub(3, "Chelsea", 30, 9, 2, 2, 15, 30, 11, 19);
FootballClub mCity = new FootballClub(4, "Man City", 29, 9, 2, 4, 15, 41, 15, 26);
FootballClub everton = new FootballClub(5, "Everton", 28, 7, 1, 7, 15, 23, 14, 9);
FootballClub tot = new FootballClub(6, "Tottenham", 27, 8, 4, 3, 15, 15, 16, -1);
FootballClub newcastle = new FootballClub(7, "Newcastle", 26, 8, 5, 2, 15, 20, 21, -1);
FootballClub south = new FootballClub(8, "Southampton", 23, 6, 4, 5, 15, 19, 14, 5);
}
Can somebody please help me?
I've trying and trying for days.
Thank you.
"The problem is that i cant find a way to set a fixed number of rows"
You don't need to set the number of rows. Use a TableModel. A DefaultTableModel in particular.
String col[] = {"Pos","Team","P", "W", "L", "D", "MP", "GF", "GA", "GD"};
DefaultTableModel tableModel = new DefaultTableModel(col, 0);
// The 0 argument is number rows.
JTable table = new JTable(tableModel);
Then you can add rows to the tableModel with an Object[]
Object[] objs = {1, "Arsenal", 35, 11, 2, 2, 15, 30, 11, 19};
tableModel.addRow(objs);
You can loop to add your Object[] arrays.
Note: JTable does not currently allow instantiation with the input data as an ArrayList. It must be a Vector or an array.
See JTable and DefaultTableModel. Also, How to Use JTable tutorial
"I created an arrayList from it and I somehow can't find a way to store this information into a JTable."
You can do something like this to add the data
ArrayList<FootballClub> originalLeagueList = new ArrayList<FootballClub>();
originalLeagueList.add(new FootballClub(1, "Arsenal", 35, 11, 2, 2, 15, 30, 11, 19));
originalLeagueList.add(new FootballClub(2, "Liverpool", 30, 9, 3, 3, 15, 34, 18, 16));
originalLeagueList.add(new FootballClub(3, "Chelsea", 30, 9, 2, 2, 15, 30, 11, 19));
originalLeagueList.add(new FootballClub(4, "Man City", 29, 9, 2, 4, 15, 41, 15, 26));
originalLeagueList.add(new FootballClub(5, "Everton", 28, 7, 1, 7, 15, 23, 14, 9));
originalLeagueList.add(new FootballClub(6, "Tottenham", 27, 8, 4, 3, 15, 15, 16, -1));
originalLeagueList.add(new FootballClub(7, "Newcastle", 26, 8, 5, 2, 15, 20, 21, -1));
originalLeagueList.add(new FootballClub(8, "Southampton", 23, 6, 4, 5, 15, 19, 14, 5));
for (int i = 0; i < originalLeagueList.size(); i++){
int position = originalLeagueList.get(i).getPosition();
String name = originalLeagueList.get(i).getName();
int points = originalLeagueList.get(i).getPoinst();
int wins = originalLeagueList.get(i).getWins();
int defeats = originalLeagueList.get(i).getDefeats();
int draws = originalLeagueList.get(i).getDraws();
int totalMatches = originalLeagueList.get(i).getTotalMathces();
int goalF = originalLeagueList.get(i).getGoalF();
int goalA = originalLeagueList.get(i).getGoalA();
in ttgoalD = originalLeagueList.get(i).getTtgoalD();
Object[] data = {position, name, points, wins, defeats, draws,
totalMatches, goalF, goalA, ttgoalD};
tableModel.add(data);
}
You probably need to use a TableModel (Oracle's tutorial here)
How implements your own TableModel
public class FootballClubTableModel extends AbstractTableModel {
private List<FootballClub> clubs ;
private String[] columns ;
public FootBallClubTableModel(List<FootballClub> aClubList){
super();
clubs = aClubList ;
columns = new String[]{"Pos","Team","P", "W", "L", "D", "MP", "GF", "GA", "GD"};
}
// Number of column of your table
public int getColumnCount() {
return columns.length ;
}
// Number of row of your table
public int getRowsCount() {
return clubs.size();
}
// The object to render in a cell
public Object getValueAt(int row, int col) {
FootballClub club = clubs.get(row);
switch(col) {
case 0: return club.getPosition();
// to complete here...
default: return null;
}
}
// Optional, the name of your column
public String getColumnName(int col) {
return columns[col] ;
}
}
You maybe need to override anothers methods of TableModel, depends on what you want to do, but here is the essential methods to understand and implements :)
Use it like this
List<FootballClub> clubs = getFootballClub();
TableModel model = new FootballClubTableModel(clubs);
JTable table = new JTable(model);
Hope it help !
I created an arrayList from it and I somehow can't find a way to store this information into a JTable.
The DefaultTableModel doesn't support displaying custom Objects stored in an ArrayList. You need to create a custom TableModel.
You can check out the Bean Table Model. It is a reusable class that will use reflection to find all the data in your FootballClub class and display in a JTable.
Or, you can extend the Row Table Model found in the above link to make is easier to create your own custom TableModel by implementing a few methods. The JButtomTableModel.java source code give a complete example of how you can do this.
You can do something like what i did with my List< Future< String > > or any other Arraylist, Type returned from other class called PingScan that returns List> because it implements service executor. Anyway the code down note that you can use foreach and retrieve data from the List.
PingScan p = new PingScan();
List<Future<String>> scanResult = p.checkThisIP(jFormattedTextField1.getText(), jFormattedTextField2.getText());
for (final Future<String> f : scanResult) {
try {
if (f.get() instanceof String) {
String ip = f.get();
Object[] data = {ip};
tableModel.addRow(data);
}
} catch (InterruptedException | ExecutionException ex) {
Logger.getLogger(gui.class.getName()).log(Level.SEVERE, null, ex);
}
}
Basic method for beginners like me.
public void loadDataToJtable(ArrayList<String> liste){
rows = table.getRowCount();
cols = table.getColumnCount();
for (int i = 0; i < rows ; i++) {
for ( int k = 0; k < cols ; k++) {
for (int h = 0; h < list1.size(); h++) {
String b = list1.get(h);
b = table.getValueAt(i, k).toString();
}
}
}
}
I wanted to write sieve of Eratosthenes which will work using specific number of threads. I figured out, that it will work in following way:
For 2 threads up to 17.
Thread-1 takes 2, and starts to remove multiple of 2 from List. Parallel Thread-2 takes 3 and does the same. After that Thread-1 takes 5( because there is no 4 in List) and Thread-2 takes 7 and so on until they reach end.
I wrote following piece of code:
private List<Integer> array = new ArrayList<Integer>();
private List<Integer> results = new ArrayList<Integer>();
public synchronized void run(){
while(array.size() > 0){
Integer tmp = array.get(0);
for(int i = 1; i < array.size(); i++){
if( (array.get(i).intValue() % tmp.intValue()) == 0)
array.remove(i);
}
results.add(array.get(0));
array.remove(0);
}
}
public void setArray(int x){
for(int i = 2; i < x; i++)
array.add(Integer.valueOf(i));
}
public void printArray(){
for(Integer i: results){
System.out.println(i);
}
}
This code works, but I added time measurement "tool" to my main class:
ThreadTask task = new ThreadTask();
task.setArray(5000);
Long beg = new Date().getTime();
for(int i = 0; i < 3;i++){
new Thread(task).start();
}
Long sleep = 1000L;
Thread.sleep(sleep);// I am sleeping main thread to wait until other Threads are done
task.printArray();
System.out.println("Time is "+(new Date().getTime()-beg-sleep));
The problem is that running this with 2 threads is slower than running with 1 thread, and 3 threads are slower than 2 threads. Could anyone explain me, why?
EDIT:
There is one important thing about that. I don't need it to be done as fast as it can be. I need it working on Threads for one reason. My Teacher wants to compare runtimes of running same program with 1, 2 .. n threads. Results should look like in this graph.
EDIT2:
I have rewritten code to following
private HashMap<Integer,Boolean> array = new HashMap<Integer,Boolean>();
private int counter = 1;
private int x;
public void run(){
while(counter < x-1){
do{
counter++;
}
while( array.get(counter));
int tmp = counter;
for(int i = tmp; i < array.size(); i+=tmp){
if( i!= tmp)
array.put(i,true);
}
try{
Thread.sleep(0L, 1);
}
catch (Exception e){}
}
}
public void setArray(int x){
this.x = x;
for(int i = 2; i < x; i++)
array.put(i, false);
}
public void printArray(){
for(int i = 2; i < array.size();i++){
if( !array.get(i))
System.out.println(i);
}
}
Now it uses HashMap and this is how it works:
Fill HashMap with keys from 2 to n and false values.
New thread goes into while loop which is based on counter variable. Counter represents current key.
Increment counter on the begging so new threads doesn't operate on counter of earlier started thread.
Put counter value into temporary variable tmp so we can work even when another thread increment counter
Iterate through the HashMap by incrementing i with tmp ( it is actually jumping on the multiplies of i) and set their values to true.
All keys which has true value are ignored in print method. Also counter skips them when incremented.
The problem is that it still works slower with more threads. What's wrong now?
The mistake is simpler than I first thought. All your threads are doing the same thing so each thread does more work. To make a multi-threaded program work faster you have to divide up the work, which has to be performed concurrently.
When you have one thread accessing a data structure, it can be in the fastest cache of one core, use multiple threads and they need to co-ordinate their actions and since most of the work is updating the data structure, a lot of time is lost as overhead. This is the case even though your data structure is not thread safe and is likely to have a corrupted result.
BTW updating an ArrayList is very expensive and using a collection objects is also an overhead.
You will get a much faster result using a BitSet and just one thread.
public class BitSetSieveMain {
private final BitSet set;
private final int size;
public BitSetSieveMain(int x) {
size = x + 1;
set = new BitSet(size);
set.flip(2, size);
}
public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
long start = System.nanoTime();
BitSetSieveMain bitSetSieveMain = new BitSetSieveMain(5000);
bitSetSieveMain.sieve();
long time = System.nanoTime() - start;
System.out.println(time / 1000 + " micro-seconds to perform " + bitSetSieveMain);
}
}
public void sieve() {
int i = 2;
do {
for (int j = i*2; j < size; j += i)
set.clear(j);
i = set.nextSetBit(i+1);
} while (i > 0);
}
public String toString() {
return set.toString();
}
}
finally prints
87 micro-seconds to perform {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357, 2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411, 2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531, 2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633, 2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791, 2797, 2801, 2803, 2819, 2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887, 2897, 2903, 2909, 2917, 2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999, 3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061, 3067, 3079, 3083, 3089, 3109, 3119, 3121, 3137, 3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209, 3217, 3221, 3229, 3251, 3253, 3257, 3259, 3271, 3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331, 3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391, 3407, 3413, 3433, 3449, 3457, 3461, 3463, 3467, 3469, 3491, 3499, 3511, 3517, 3527, 3529, 3533, 3539, 3541, 3547, 3557, 3559, 3571, 3581, 3583, 3593, 3607, 3613, 3617, 3623, 3631, 3637, 3643, 3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709, 3719, 3727, 3733, 3739, 3761, 3767, 3769, 3779, 3793, 3797, 3803, 3821, 3823, 3833, 3847, 3851, 3853, 3863, 3877, 3881, 3889, 3907, 3911, 3917, 3919, 3923, 3929, 3931, 3943, 3947, 3967, 3989, 4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049, 4051, 4057, 4073, 4079, 4091, 4093, 4099, 4111, 4127, 4129, 4133, 4139, 4153, 4157, 4159, 4177, 4201, 4211, 4217, 4219, 4229, 4231, 4241, 4243, 4253, 4259, 4261, 4271, 4273, 4283, 4289, 4297, 4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391, 4397, 4409, 4421, 4423, 4441, 4447, 4451, 4457, 4463, 4481, 4483, 4493, 4507, 4513, 4517, 4519, 4523, 4547, 4549, 4561, 4567, 4583, 4591, 4597, 4603, 4621, 4637, 4639, 4643, 4649, 4651, 4657, 4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729, 4733, 4751, 4759, 4783, 4787, 4789, 4793, 4799, 4801, 4813, 4817, 4831, 4861, 4871, 4877, 4889, 4903, 4909, 4919, 4931, 4933, 4937, 4943, 4951, 4957, 4967, 4969, 4973, 4987, 4993, 4999}
I need to create an array of integers contained within an array of words. I keep getting an error
cannot convert from int[] to java.lang.String[]
where it says
private String[][] expenseName = {clothes, tuition, transportation, food, housing, books};
This is my code
public class Budget{
///////////////fields////////////////
int expenseAmount[] = {1000, 2000, 3000, 4000, 5000, 6000};
int monthNumber[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
int clothes[]= {100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210};
int tuition[] = {200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200};
int transportation[]={100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210};
int food[]={80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80};
int housing[]={150, 150, 150, 150, 150, 150, 150, 150, 150, 150, 150};
int books[]= {200, 0, 0, 0, 0, 0, 0, 300, 0, 0, 0, 0};
int i=0; // this is arbitrary. Never hard code numbers unless that number is never going to change. in that case you make a variable and define it.
int month_num;
private String[][] expenseName = {clothes, tuition, transportation, food, housing, books};
/////////constructors///////////////
public Budget() {}
public Budget(int name) {this.expenseName[i][i] = name;}
public Budget(String name, int clothes, int tuition, int transportation, int food, int housing, int books)
{
this.expenseName[i] = name;
this.clothes[i] = clothes;
this.tuition[i] = tuition;
this.transportation[i] = transportation;
this.food[i] = food;
this.housing[i] = housing;
this.books[i] = books;
this.monthNumber[i] = month_num;
}
/////////////methods///////////
public String getexpenseName() {return expenseName[i][i];}
public int getclothes() {return clothes[i];}//change the I
public int gettuition() {return tuition[i];}
public int gettransporation() {return transportation[i];}
public int getfood() {return food[i];}
public int gethousing() {return housing[i];}
public int books() {return books[i];}
public int getmonthNumber() {return monthNumber[i];}//change the i
public void setExpenseName(String name)
{
this.expenseName[i][i] = name;
}
public boolean setexpenseAmount(int num)
{
if (this.expenseAmount[i] == 0)
{this.expenseAmount[i] = num;
return true;
}
else
return false;
You need quotes around your strings:
private String[] expenseName = {"clothes", "tuition", "etc"};
or you need to declare it int[][]
private int[][] expenseName = {clothes, tuition};
As the error message clearly states, you can't put an int[] into an array of String[]s.
Change
private String[][] expenseName = {clothes, tuition, transportation, food, housing, books};
to
private int[][] expenseName = {clothes, tuition, transportation, food, housing, books};
In Java, you cannot use an array of int as an array of String.
That will just not work, like the error says.
I guess that you must be familiar with some language where there is no type checking and you can do whatever you want. But this is Java.
You have to convert the int[] to String[], for example like this.
public class ArrayIntToString {
public static void main(String[] args) {
int[] numbers = { 1, 2, 3 };
String[] numbersAsStrings = new String[numbers.length];
int i = 0;
for (Integer number : numbers) {
numbersAsStrings[i++] = number.toString();
}
}
}