Java String to String[] of possible prefixes - java

I would like to create an array of prefixes to iterate through from a string.
This is to create some tests where the options are matched using String.startsWith
For example "start" would become { "s", "st", "sta", "star", "start" }

You can try below code,
String str = "start";
String strArray[] = new String [str.length()];
for (int i=0 ; i< str.length() ; i++)
{
strArray[i] = str.substring(0,i+1);
System.out.println("strArray["+i+"] = " +strArray[i] );
}
Output:
strArray[0] = s
strArray[1] = st
strArray[2] = sta
strArray[3] = star
strArray[4] = start

Related

write to separate columns in csv

I am trying to write 2 different arrays to a csv. The first one I want in the first column, and second array in the second column, like so:
array1val1 array2val1
array1val2 array2val2
I am using the following code:
String userHomeFolder2 = System.getProperty("user.home") + "/Desktop";
String csvFile = (userHomeFolder2 + "/" + fileName.getText() + ".csv");
FileWriter writer = new FileWriter(csvFile);
final String NEW_LINE_SEPARATOR = "\n";
FileWriter fileWriter;
CSVPrinter csvFilePrinter;
CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR);
fileWriter = new FileWriter(fileName.getText());
csvFilePrinter = new CSVPrinter(fileWriter, csvFileFormat);
try (PrintWriter pw = new PrintWriter(csvFile)) {
pw.printf("%s\n", FILE_HEADER);
for(int z = 0; z < compSource.size(); z+=1) {
//below forces the result to get stored in below variable as a String type
String newStr=compSource.get(z);
String newStr2 = compSource2.get(z);
newStr.replaceAll(" ", "");
newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
pw.printf("%s\n", explode, explode2);
}
}
catch (Exception e) {
System.out.println("Error in csvFileWriter");
e.printStackTrace();
} finally {
try {
fileWriter.flush();
fileWriter.close();
csvFilePrinter.close();
} catch (IOException e ) {
System.out.println("Error while flushing/closing");
}
}
However I am getting a strange output into the csv file:
[Ljava.lang.String;#17183ab4
I can run
pw.printf("%s\n", explode);
pw.printf("%s\n", explode2);
Instead of : pw.printf("%s\n", explode, explode2);
and it prints the actual strings but all in one same column.
Does anyone know how to solve this?
1.Your explode and explode2 are actually String Arrays. You are printing the arrays and not the values of it. So you get at the end the ADRESS of the array printed.
You should go through the arrays with a loop and print them out.
for(int i = 0; i<explode.length;++i) {
pw.printf("%s%s\n", explode[i], explode2[i]);
}
2.Also the method printf should be look something like
pw.printf("%s%s\n", explode, explode2);
because youre are printing two arguments, but in ("%s\n", explode, explode2) is only one printed.
Try it out and say if it worked
After these lines:
newStr.replaceAll(" ", "");
newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
Use this code:
int maxLength = Math.max(explode.length, explode2.length);
for (int i = 0; i < maxLength; i++) {
String token1 = (i < explode.length) ? explode[i] : "";
String token2 = (i < explode2.length) ? explode2[i] : "";
pw.printf("%s %s\n", token1, token2);
}
This also cover the case that the arrays are of different length.
I have removed all unused variables and made some assumptions about content of compSource.
Moreover, don't forget String is immutable. If you just do "newStr.replaceAll(" ", "");", the replacement will be lost.
public class Tester {
#Test
public void test() throws IOException {
// I assumed compSource and compSource2 are like bellow
List<String> compSource = Arrays.asList("array1val1,array1val2");
List<String> compSource2 = Arrays.asList("array2val1,array2val2");
String userHomeFolder2 = System.getProperty("user.home") + "/Desktop";
String csvFile = (userHomeFolder2 + "/test.csv");
try (PrintWriter pw = new PrintWriter(csvFile)) {
pw.printf("%s\n", "val1,val2");
for (int z = 0; z < compSource.size(); z++) {
String newStr = compSource.get(z);
String newStr2 = compSource2.get(z);
// String is immutable --> store the result otherwise it will be lost
newStr = newStr.replaceAll(" ", "");
newStr2 = newStr2.replaceAll(" ", "");
String[] explode = newStr.split(",");
String[] explode2 = newStr2.split(",");
for (int k = 0; k < explode.length; k++) {
pw.println(explode[k] + "\t" + explode2[k]);
}
}
}
}
}

How can i split String in java with custom pattern

I am trying to get the location data from this string using String.split("[,\\:]");
String location = "$,lat:27.980194,lng:46.090199,speed:0.48,fix:1,sats:6,";
String[] str = location.split("[,\\:]");
How can i get the data like this.
str[0] = 27.980194
str[1] = 46.090199
str[2] = 0.48
str[3] = 1
str[4] = 6
Thank you for any help!
If you just want to keep the numbers (including dot separator), you can use:
String[] str = location.split("[^\\d\\.]+");
You will need to ignore the first element in the array which is an empty string.
That will only work if the data names don't contain numbers or dots.
String location = "$,lat:27.980194,lng:46.090199,speed:0.48,fix:1,sats:6,";
Matcher m = Pattern.compile( "\\d+\\.*\\d*" ).matcher(location);
List<String> allMatches = new ArrayList<>();
while (m.find( )) {
allMatches.add(m.group());
}
System.out.println(allMatches);
Quick and Dirty:
String location = "$,lat:27.980194,lng:46.090199,speed:0.48,fix:1,sats:6,";
List<String> strList = (List) Arrays.asList( location.split("[,\\:]"));
String[] str = new String[5];
int count=0;
for(String s : strList){
try {
Double d =Double.parseDouble(s);
str[count] = d.toString();
System.out.println("In String Array:"+str[count]);
count++;
} catch (NumberFormatException e) {
System.out.println("s:"+s);
}
}

Reverse a string as per length of first word

I am new to Java Strings.
Actually I have the code to reverse words:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Test2 {
public static void main(String[] args) throws IOException
{
System.out.println("enter a sentence");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String rev =br.readLine();
String [] bread = rev.split(" ");
for(int z =bread.length-1;z>=0;z--)
{
System.out.println(bread[z]);
}
}
}
For the above code I get:
Input :Bangalore is a city
Output: City is a Bangalore
But I want the output to be like below:
Input: Bangalore is a city
Output:cityaisba ng a lore
Another Example:
Input: Hello Iam New To Java.Java is object Oriented language.
Output: langu age Ori en tedo bjec ti sjava. javaToNe wIamolleH
Please help me out
Here is one way you could do it:
String rev = br.readLine();
String [] bread = rev.split(" ");
int revCounter = 0;
for(int z = bread.length - 1; z >= 0; z--)
{
String word = bread[z];
for(int i = 0; i < word.length(); i++)
{
// If char at current position in 'rev' was a space then
// just print space. Otherwise, print char from current word.
if(rev.charAt(revCounter) == ' ')
{
System.out.print(' ');
i--;
}
else
System.out.print(word.charAt(i));
revCounter++;
}
}
When I run your code I get following result:
city
a
is
Bangalore
So to have it in a single line, why don't you add a space and print a single line?
System.out.println("enter a sentence");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String rev = br.readLine();
String[] bread = rev.split(" ");
for (int z = bread.length - 1; z >= 0; z--) {
System.out.print(bread[z] + " ");
}
I didn't check the validity of your code like GHajba did. But if you want spaces to remain on specific places it might be an option to remove all spaces and put them back according to their index in the original String.
Remove all
newBread = newBread.replace(" ", "");
Put them back
StringBuilder str = new StringBuilder(newBread);
for (int index = oldBread.indexOf(" ") ;
index >= 0 ;
index = oldBread.indexOf(" ", index + 1))
{
str.insert(index, ' ');
}
newBread = str.toString();
I came up with this quick and there might be better ways to do this, maybe without StringBuilder, but this might help you until you find a better way.
Try with this (i've used a string as input):
String original = "Bangalore is a city";
System.out.println("Original : "+original);
StringBuilder inverted = new StringBuilder();
StringBuilder output = new StringBuilder();
String temp = "";
String[] split = original.split("\\s+");
for (int i = split.length - 1; i >= 0; i--) {
inverted.append(split[i]);
}
temp = inverted.toString();
for (String string : split) {
int currLenght = string.length();
String substring = temp.substring(0,currLenght);
temp = temp.replaceAll(substring, "");
output.append(substring).append(" ");
}
System.out.println("Converted : "+output.toString());
Append the reversed words without the spaces into a StringBuffer.
StringBuffer b = new StringBuffer();
for (int i = bread.length-1; i >= 0 ; i--) {
b.append(bread[i]);
}
Then insert the spaces of the original String into the StringBuffer.
int spaceIndex, prevIndex = 0;
while ((spaceIndex = rev.indexOf(" ", prevIndex + 1)) != -1) {
b.insert(spaceIndex, ' ');
prevIndex = spaceIndex;
}

Tokenize devnagari words into letters

I have something like
a = "बिक्रम मेरो नाम हो"
I want to achieve something like in Java
a[0] = बि
a[1] = क्र
a[3] = म
Java internally stores each character of any language in UTF-16(2 bytes) so you can safely access the characters individually.
Try This:
String a = "बिक्रम मेरो नाम हो";
int strLen = a.length();
char array[] = new char[strLen];
String strArray1[] = new String[strLen];
for (int i=0 ; i< strLen ; i++)
{
array[i] = a.charAt(i);
strArray1[i] = Character.toString(a.charAt(i));
System.out.println ("Index = " + i + "* Char = " +array[i] + "** String =" +strArray1[i] );
}
Output:
Index = 0* Char = ब** String =ब
Index = 1* Char = ि** String =ि
Index = 2* Char = क** String =क
Index = 3* Char = ्** String =्
Index = 4* Char = र** String =र
Index = 5* Char = म** String =म
Index = 6* Char = ** String =
Index = 7* Char = म** String =म
Index = 8* Char = े** String =े
Index = 9* Char = र** String =र
Index = 10* Char = ो** String =ो
Index = 11* Char = ** String =
Index = 12* Char = न** String =न
Index = 13* Char = ा** String =ा
Index = 14* Char = म** String =म
Index = 15* Char = ** String =
Index = 16* Char = ह** String =ह
Index = 17* Char = ो** String =ो
Note:
In order to allow eclipse to allow you to save your java program with foreign characters(Hindi alphabets), do the following:
Go to:
"Windows > Preferences > General > Content Types > Text > {Choose file type}
{Selected file type} > Default encoding > UTF-8" and click Update.
Did you try icu4j?
BreakIterator character instance has a possibility to split String to characters
My code is not at all optimized, sorry about that but it works!
Just change the path of the file in which you are going to enter the devnagri sentence and it should work.
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new FileReader("/home/ubuntu/Documents/trainforjava.txt")); //PLEASE ENTER PATH HERE
String[] devFull = new String[]{
"अ","आ", "इ", "ई", "उ", "ऊ", "ऋ"
, "ऌ" ,"ऍ", "ए", "ऐ", "ऑ", "ओ", "औ",
"क", "ख", "ग", "घ" ,"ङ",
"च" ,"छ" ,"ज"," झ"," ञ",
"ट","ठ", "ड"," ढ"," ण",
"त", "थ", "द", "ध", "न",
"प", "फ", "ब"," भ","म",
"य", "र", "ल", "ळ",
"व", "श" ,"ष","स" ,"ह"
};
String[] uniDev = new String[]
{
"905","906","907","908","909","90a","90b",
"90c","90d","90f","910","911","913","914",
"915","916","917","918","919",
"91a","91b","91c","91d","91e",
"91f","920","921","922","923",
"924","925","926","927","928",
"92a","92b","92c","92d","92e",
"92f","930","932","933",
"935","936","937","938","939"
};
String[] devHalf = new String[]
{
"$़","ऽ","$ा","$ि" ,
"$ी", "$ ु","$ू","$ृ","$ॄ","$ॅ",
"$े","$ै","$ॉ",
"$ो","$ौ"
};
String[] gujHalf = new String[]
{
"$઼","ઽ","$ા","$િ" ,
"$ી","$ુ","$ૂ","$ૃ","$ૄ","$ૅ",
"$ે","$ૈ","$ૉ",
"$ો","$ૌ"
};
try
{
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while( (line = br.readLine() ) != null)
{
line=line.replaceAll(" ", ""); //remove white spaces if any
System.out.println();
//System.out.println(line);
int strLength = line.length();
// String a = "बिक्रम मेरो नाम हो";
int strLen = line.length();
char array[] = new char[strLen];
String strArray1[] = new String[strLen];
int mark[] = new int[strLen+1];
String unis[]=new String[strLen];
int cnt=0;
String newCharD[]=new String [strLen];
String newCharG[]=new String [strLen];
String tempD=null;
String tempG=null;
String arr = null;
String next =null;
String temp=null;
String uniNext=null;
int hold=0;
int j=0;
for (int i=0 ; i< strLen ; i++)
{
j=i+1;
array[i] = line.charAt(i);
strArray1[i] = Character.toString(line.charAt(i));
if(i<(strLen-1))
{
char nbit = line.charAt(j);
next=Character.toString(line.charAt(j));
uniNext=Integer.toHexString(nbit);
//System.out.print("\nUninext:\t"+uniNext);
}
unis[i]=Integer.toHexString(array[i]);
mark[strLen]=1;
if((Arrays.asList(devFull).contains(Character.toString(array[i]))) && (!uniNext.equalsIgnoreCase("94d")) )
{
mark[i]=1;
}
else
{
mark[i]=0;
}
//
//System.out.println();
//System.out.println ("Index = " + i + "* Char = " +array[i] + "** String =" +strArray1[i]+ "Unicode="+unis[i]+"Mark="+mark[i]);
//System.out.print(unis[i].toString());
}
int start=0;
start=0;
for(int l1=0;l1<=strLen;l1++)
{
//start=0;
if(l1==0)
{
temp=Character.toString(array[l1]);
}
else
{
if(mark[l1]==0)
{
temp=temp+Character.toString(array[l1]);
}
else
{
System.out.print(" "+temp);
newCharD[start]=temp;
start++;
temp=null;
if(l1!=strLen)
{
temp=Character.toString(array[l1]);
}
}
}
}
/* for(int s=0;s<start;s++)
{
System.out.print(" "+newCharD[s]);
}*/
for(int s=0;s<start;s++)
{
}
}
}
finally {
br.close();
}
//PrintStream out = new PrintStream(new //FileOutputStream("/home/ubuntu/Documents/trainforjavaoutput.txt"));
//System.setOut(out);
}
Try this for Hindi :-
import java.io.*;
import java.text.BreakIterator;
import java.util.Locale;
public class Test {
public static void main(String[] args) throws IOException
{
String text = "बिक्रम मेरो नाम हो";
Locale hindi = new Locale("hi", "IN");
BreakIterator breaker = BreakIterator.getCharacterInstance(hindi);
breaker.setText(text);
int start = breaker.first();
for (int end = breaker.next();
end != BreakIterator.DONE;
start = end, end = breaker.next()) {
System.out.println(text.substring(start,end));
}
}
}
OUTPUT:-
बि
क्र
म
मे
रो
ना
म
हो
BreakIterator Java Documentation: https://docs.oracle.com/javase/tutorial/i18n/text/about.html
In order to split the string by letters rather than characters, going by dvasanth's suggestion, you can try below:
String x = "बिक्रम मेरो नाम हो";
x=x.replaceAll(" ", ""); // Remove all spaces
int strLength = x.length();
String [] letterArray = new String (strLength /2);
String combined = "";
for (int i=0, j=0; i < strLength ; i=i+2,j++)
{
strArray1[i] = Character.toString(x.charAt(i));
if (i+1 < strLength)
{
strArray1[i+1] = Character.toString(x.charAt(i+1));
combined = strArray1[i]+strArray1[i+1]; // This line provides the letters.
// Assumption is that each letter is 2 unicode characters long.
}
else
{
combined = strArray1[i];
}
letterArray [j] = combined;
System.out.println("Split string by letters is : "+combined);
System.out.println("Split string by letters in array is : "+letterArray [j]);
}
Output is:
Split string by letters is : बि
Split string by letters is : क्
Split string by letters is : रम
Split string by letters is : मे
Split string by letters is : रो
Split string by letters is : ना
Split string by letters is : मह
Split string by letters is : ो
Note:
In order to allow eclipse to allow you to save your java program with foreign characters(Hindi alphabets), do the following:
Go to:
"Windows > Preferences > General > Content Types > Text > {Choose file type}
{Selected file type} > Default encoding > UTF-8" and click Update.

Divide String by StringTokenizer and then save to 2 arrays

Imagine this array.
data[0] : 208.92.249.53:80
data[1] : 115.124.65.74:3128
data[2] : 49.213.17.92:8080
I want to split data[]. And extract ip and port number.
ip[0] : 208.92.249.53
ip[1] : 115.124.65.74
ip[2] : 49.213.17.92
port[0] : 80
port[1] : 3128
port[2] : 8080
How can I do that?
StringTokenizer stringTokenizer = new StringTokenizer(data[i], ":");
while (stringTokenizer.hasMoreTokens()){
//??????
}
I don't know how can I save to 2 different array. please let me show how to do that... Thank you!
String[] ip = new String[data.length];
String[] port = new String[data.length];
for (int i=0;i<data.length;i++) {
String[] split = data[i].split(":");
ip[i] = split[0];
port[i] = split[1];
}
StringTokenizer ist deprecated use array.split() instead.
String[] tmp = data[i].split(":");
ip[i] = tmp[0];
port[i] = tmp[1];
Try,
for(int i=0;i<data.length;i++){
StringTokenizer stringTokenizer = new StringTokenizer(data[i], ":");
while (stringTokenizer.hasMoreTokens()) {
ip[i]=stringTokenizer.nextToken();
port[i]=stringTokenizer.nextToken();
}
}
String[] arrTokens =data[0].split(":");
Maybe StringTokenizer is not what you want. You can do this via split command
String[] ip = new String[data.length];
String[] port = new String[data.length];
for (int i = 0; i < data.length; i++)
{
String[] splitted = data[i].split(":");
ip[i] = splitted[0];
port[i] = splitted[1];
}

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