Develop Reference

Print a string from ArrayList of String[] per Index?

How to print ArrayList of String[] into String per index
with expected Output like this
Nama: John
Kimia: 10
biologi: 9
fisika: 8
Nama: Peter
Kimia: 7
biologi: 8
fisika: 10
Nama: Steve
Kimia: 6
biologi: 9
fisika: 8
Here is the code and how to print it?
public static String dataSiswa(ArrayList<String[]> list_Siswa){
for (String[] dataSiswa : list_Siswa){
String nama = dataSiswa[0];
String kimia = dataSiswa[1];
String biologi = dataSiswa[2];
String fisika = dataSiswa[3];
data = "Nama: " + nama;
}
return data;
}

You were pretty close to it:
public static String dataSiswa(ArrayList<String[]> list_Siswa){
String data = "";
for (String[] dataSiswa : list_Siswa){
data += "Nama: " + dataSiswa[0] + "\n" +
"Kimia" + dataSiswa[1] + "\n" +
"Biologi" + dataSiswa[2] + "\n" +
"Fisika" + dataSiswa[3] + "\n\n";
}
return data;
}
This generates your String to be outputted. Printing:
System.out.print(yourArrayList);
Just don't forget to initialize yourArrayList prior of the method call.

Recommend using a StringBuilder and appending the desired values together with a \n at the end for a new line. General form could look like this:
public static String dataSiswa(ArrayList<String[]> list_Siswa){
String[] sections = {"Nama: ", "Kimia: ", "biologi: ", "fisika: "};
StringBuilder builder = new StringBuilder();
for (String[] dataSiswa : list_Siswa) {
for(int i = 0; i < dataSiswa.length; i++) {
builder.append(sections[i]).append(dataSiswa[i]).append("\n");
}
builder.append("\n"); //Extra space between data chunks added here
}
return builder.toString();
}

Separate into column without using split function

I am trying to separate these value into ID, FullName and Phone. I know we can split it by using java split function. But is there any other ways to separate it? Values:
1 Peater John 2522523254
10 Neal Tom 2522523254
11 Tom Jackson 2522523254
111 Jack Smith 2522523254
12 Brownson Black 2522523254
I tried to use substring method but it won't work properly.
String id = line.substring(0, 3);
If I do this then it will work till 4th line, but other won't work properly.

If it is fixed length you can use String.substring(). But you should also trim() the result before you try to convert it to numeric:
String idTxt=line.substring(0,4);
Long id=Long.parseLong(idTxt.trim());
String name=line.substring(5,25).trim(); // or whatever the size is of name column.

You can use regex and Pattern
Pattern pattern = Pattern.compile("(\\d*)\s*([\\w\\s]*)\\s*(\\d*)");
Matcher matcher = pattern.matcher(content);
if (matcher.find()) {
string id = matcher.group(0);
string name = matcher.group(1);
string phone = matcher.group(2);
}

package Generic;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
class Main
{
public static void main(String[] args)
{
String txt=" 12 Brownson Black 2522523254";
String re1=".*?"; // Non-greedy match on filler
String re2="(\\d+)"; // Integer Number 1
String re3="(\\s+)"; // White Space 1
String re4="((?:[a-z][a-z]+))"; // Word 1
String re5="(\\s+)"; // White Space 2
String re6="((?:[a-z][a-z]+))"; // Word 2
String re7="(\\s+)"; // White Space 3
String re8="(\\d+)"; // Integer Number 2
Pattern p = Pattern.compile(re1+re2+re3+re4+re5+re6+re7+re8,Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
Matcher m = p.matcher(txt);
if (m.find())
{
int id = Integer.parseInt(m.group(1));
String name =m.group(3) + " ";
name = name+m.group(5);
long phone = Long.parseLong(m.group(7));
System.out.println(id);
System.out.println(name);
System.out.println(phone);
}
}
}

What about this:
int first_space;
int last_space;
first_space = my_string.indexOf(' ');
last_space = my_string.lastIndexOf(' ');
if ((first_space > 0) && (last_space > first_space))
{
long id;
String full_name;
String phone;
id = Long.parseLong(my_string.substring(0, first_space));
full_name = my_string.substring(first_space + 1, last_space);
phone = my_string.substring(last_space + 1);
}

Use a regexp:
private static final Pattern RE = Pattern.compile(
"^\\s*(\\d+)\\s+(\\S+(?: \\S+)*)\\s+(\\d+)\\s*$");
Matcher matcher = RE.matcher(s);
if (matcher.matches()) {
System.out.println("ID: " + matcher.group(1));
System.out.println("FullName: " + matcher.group(2));
System.out.println("Phone: " + matcher.group(3));
}

You can use a StringTokenizer for this. You won't have to worry about amount of spaces and/or tabs before or after your values, and no need for complex regex expressions:
String line = " 1 Peater John\t2522523254 ";
StringTokenizer st = new StringTokenizer(line, " \t");
String id = "";
String name = "";
String phone = "";
// The first token is your id, you can parse it to an int if you like or need it
if(st.hasMoreTokens()) {
id = st.nextToken();
}
// Loop over the remaining tokens
while(st.hasMoreTokens()) {
String token = st.nextToken();
// As long a there are other tokens, you're processing the name
if(st.hasMoreTokens()) {
if(name.length() > 0) {
name = name + " ";
}
name = name + token;
}
// If there are no more tokens, you've reached the phone number
else {
phone = token;
}
}
System.out.println(id);
System.out.println(name);
System.out.println(phone);

Words inside square brackes - RegExp

String linkPattern = "\\[[A-Za-z_0-9]+\\]";
String text = "[build]/directory/[something]/[build]/";
RegExp reg = RegExp.compile(linkPattern,"g");
MatchResult matchResult = reg.exec(text);
for (int i = 0; i < matchResult.getGroupCount(); i++) {
System.out.println("group" + i + "=" + matchResult.getGroup(i));
}
I am trying to get all blocks which are encapsulated by squared bracets form a path string:
and I only get group0="[build]" what i want is:
1:"[build]" 2:"[something]" 3:"[build]"
EDIT:
just to be clear words inside the brackets are generated with random text
public static String genText()
{
final int LENGTH = (int)(Math.random()*12)+4;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < LENGTH; x++)
{
sb.append((char)((int)(Math.random() * 26) + 97));
}
String str = sb.toString();
str = str.substring(0,1).toUpperCase() + str.substring(1);
return str;
}
EDIT 2:
JDK works fine, GWT RegExp gives this problem
SOLVED:
Answer from Didier L
String linkPattern = "\\[[A-Za-z_0-9]+\\]";
String result = "";
String text = "[build]/directory/[something]/[build]/";
RegExp reg = RegExp.compile(linkPattern,"g");
MatchResult matchResult = null;
while((matchResult=reg.exec(text)) != null){
if(matchResult.getGroupCount()==1)
System.out.println( matchResult.getGroup(0));
}

I don't know which regex library you are using but using the one from the JDK it would go along the lines of
String linkPattern = "\\[[A-Za-z_0-9]+\\]";
String text = "[build]/directory/[something]/[build]/";
Pattern pat = Pattern.compile(linkPattern);
Matcher mat = pat.matcher(text);
while (mat.find()) {
System.out.println(mat.group());
}
Output:
[build]
[something]
[build]

Try:
String linkPattern = "(\\[[A-Za-z_0-9]+\\])*";
EDIT:
Second try:
String linkPattern = "\\[(\\w+)\\]+"
Third try, see http://rubular.com/r/eyAQ3Vg68N

Java special characters RegEx

I want to achieve following using Regular expression in Java
String[] paramsToReplace = {"email", "address", "phone"};
//input URL string
String ip = "http://www.google.com?name=bob&email=okATtk.com&address=NYC&phone=007";
//output URL string
String op = "http://www.google.com?name=bob&email=&address=&phone=";
The URL can contain special characters like %

Try this expression: (email=)[^&]+ (replace email with your array elements) and replace with the group: input.replaceAll("("+ paramsToReplace[i] + "=)[^&]+", "$1");
String input = "http://www.google.com?name=bob&email=okATtk.com&address=NYC&phone=007";
String output = input;
for( String param : paramsToReplace ) {
output = output.replaceAll("("+ param + "=)[^&]+", "$1");
}

For the example above. you can use split
String[] temp = ip.split("?name=")[1].split("&")[0];
op = temp[0] + "?name=" + temp[1].split("&")[0] +"&email=&address=&phone=";

Something like this?
private final static String REPLACE_REGEX = "=.+\\&";
ip=ip+"&";
for(String param : paramsToReplace) {
ip = ip.replaceAll(param+REPLACE_REGEX, Matcher.quoteReplacement(param+"=&"));
}
P.S. This is only a concept, i didn't compile this code.

You don't need regular expressions to achieve that:
String op = ip;
for (String param : paramsToReplace) {
int start = op.indexOf("?" + param);
if (start < 0)
start = op.indexOf("&" + param);
if (start < 0)
continue;
int end = op.indexOf("&", start + 1);
if (end < 0)
end = op.length();
op = op.substring(0, start + param.length() + 2) + op.substring(end);
}

array in array list

In the input file, there are 2 columns: 1) stem, 2) affixes. In my coding, i recognise each of the columns as tokens i.e. tokens[1] and tokens[2]. However, for tokens[2] the contents are: ng ny nge
stem affixes
---- -------
nyak ng ny nge
my problem here, how can I declare the contents under tokens[2]? Below are my the snippet of the coding:
try {
FileInputStream fstream2 = new FileInputStream(file2);
DataInputStream in2 = new DataInputStream(fstream2);
BufferedReader br2 = new BufferedReader(new InputStreamReader(in2));
String str2 = "";
String affixes = " ";
while ((str2 = br2.readLine()) != null) {
System.out.println("Original:" + str2);
tokens = str2.split("\\s");
if (tokens.length < 4) {
continue;
}
String stem = tokens[1];
System.out.println("stem is: " + stem);
// here is my point
affixes = tokens[3].split(" ");
for (int x=0; x < tokens.length; x++)
System.out.println("affix is: " + affixes);
}
in2.close();
} catch (Exception e) {
System.err.println(e);
} //end of try2

You are using tokens as an array (tokens[1]) and assigning the value of a String.split(" ") to it. So it makes things clear that the type of tokens is a String[] array.
Next,
you are trying to set the value for affixes after splitting tokens[3], we know that tokens[3] is of type String so calling the split function on that string will yield another String[] array.
so the following is wrong because you are creating a String whereas you need String[]
String affixes = " ";
so the correct type should go like this:
String[] affixes = null;
then you can go ahead and assign it an array.
affixes = tokens[3].split(" ");

Are you looking for something like this?
public static void main(String[] args) {
String line = "nyak ng ny nge";
MyObject object = new MyObject(line);
System.out.println("Stem: " + object.stem);
System.out.println("Affixes: ");
for (String affix : object.affixes) {
System.out.println(" " + affix);
}
}
static class MyObject {
public final String stem;
public final String[] affixes;
public MyObject(String line) {
String[] stemSplit = line.split(" +", 2);
stem = stemSplit[0];
affixes = stemSplit[1].split(" +");
}
}
Output:
Stem: nyak
Affixes:
ng
ny
nge