swing - JAVA read text files, count numbers and write it to Jtable -

i still learning java , have been trying find solution program few days, haven't gotten fixed yet.

i have many text files (my program saves). files this:

text (tab) number (tab) number (tab)... text (tab) number (tab) number (tab)... 

(tab) means there tabulation mark, text means text (string), number means there number (integer).

number of files can 1 32 , file names like: january1; january2; january3...

i need read of files (ignore strings) , sum numbers so:

while ((line = br.readline()) != null) {      counter=counter+1;     string[] info = line.split("\\s+");      for(int j = 2; j < 8; j++) {          int num = integer.parseint(info[j]);         data[j][counter]=data[j][counter]+num;      }  }; 

simply want sum "tables" array of arrays (or similar kind of variable) , display table. if knows solution or can link similar calculation, awesome!

so, see it, have 4 questions need answered, goes against site etiquette of asking question, give shot

1. how list series of files, presumably using kind of filter
2. how read file , process data in meaningful way
3. how manage data in data structure
4. show data in jtable.

listing files

probably simplest way list files use file#list , pass filefilter meets needs

file[] files = new file(".").listfiles(new filefilter() {     @override     public boolean accept(file pathname) {         return pathname.getname().tolowercase().startswith("janurary");     } }); 

now, i'd write method took file object representing directory want list , filefilter use search it...

public file[] listfiles(file dir, filefilter filter) throws ioexception {     if (dir.exists()) {         if (dir.isdirectory()) {             return dir.listfiles(filter);         } else {             throw new ioexception(dir + " not valid directory");         }     } else {             throw new ioexception(dir + " not exist");     } } 

this way search number of different set of files based on different filefilters.

of course, use newer paths/files api find files well

reading files...

reading multiple files comes down same thing, reading single file...

// bufferedreader has nice readline method makes // easier read text with.  use scanner // prefer bufferedreader, that's me... try (bufferedreader br = new bufferedreader(new filereader(new file("...")))) {     string line = null;     // read each line     while ((line = br.readline()) != null) {         // split line individual parts, on <tab> character         string parts[] = line.split("\t");         int sum = 0;         // staring first number, sum line...         (int index = 1; index < parts.length; index++) {             sum += integer.parseint(parts[index].trim());         }         // store key/value pairs how     } } 

now, need way store results of calculations...

have @ basic i/o more details

managing data

now, there number of ways this, since amount of data variable, want data structure can grow dynamically.

my first thought use map, assumes want combining rows same name, otherwise should list within list, outer list represents rows , inner list represents column values...

map<string, integer> data = new hashmap<>(25); file[] files = listfiles(somedir, januraryfilter); (file file : files {     readfile(file, data); } 

where readfile code before

protected void readdata(file file, map<string, integer> data) throws ioexception {     try (bufferedreader br = new bufferedreader(new filereader(file))) {         string line = null;         // read each line         while ((line = br.readline()) != null) {             //...             // store key/value pairs how             string name = parts[0];             if (data.containskey(name)) {                 int previous = data.get(name);                 sum += previous;             }             data.put(name, sum);         }     } } 

have @ collections trail more details

showing data

and finally, need show data. use defaulttablemodel, have data in structure, why not re-use custom tablemodel

public class summarytablemodel extends abstracttablemodel {      private map<string, integer> data;     private list<string> keymap;      public summarytablemodel(map<string, integer> data) {         this.data = new hashmap<>(data);         keymap = new arraylist<>(data.keyset());     }      @override     public int getrowcount() {         return data.size();     }      @override     public int getcolumncount() {         return 2;     }      @override     public class<?> getcolumnclass(int columnindex) {         class type = object.class;         switch (columnindex) {             case 0:                 type = string.class;                 break;             case 1:                 type = integer.class;                 break;         }         return type;     }      @override     public object getvalueat(int rowindex, int columnindex) {         object value = null;         switch (columnindex) {             case 0:                 value = keymap.get(rowindex);                 break;             case 1:                 string key = keymap.get(rowindex);                 value = data.get(key);                 break;         }         return value;     }  } 

then apply jtable...

add(new jscrollpane(new jtable(new summarytablemodel(data))); 

take @ how use tables more details

conclusion

there lot of assumptions have made missing context of question; order of files matter? care duplicate entries?

so becomes near impossible provide single "answer" solve of problems