Develop Reference

String[] cannot be converted to State[]

Just wondering what I have done wrong here I'm getting an error in the method setLine() which is:
error: incompatible types: String[] cannot be converted to State[]
Im not too sure on what to do to fix it since I need the line to be split and stored in that state array so I can determine whether if it is a state or location when reading from a csv file.
public static void readFile(String inFilename)
{
FileInputStream fileStrm = null;
InputStreamReader rdr;
BufferedReader bufRdr;
int stateCount = 0, locationCount = 0;
String line;
try
{
fileStrm = new FileInputStream(inFilename);
rdr = new InputStreamReader(fileStrm);
bufRdr = new BufferedReader(rdr);
line = bufRdr.readLine();
while (line != null)
{
if (line.startsWith("STATE"))
{
stateCount++;
}
else if (line.startsWith("LOCATION"))
{
locationCount++;
}
line = bufRdr.readLine();
}
fileStrm.close();
State[] state = new State[stateCount];
Location[] location = new Location[locationCount];
}
catch (IOException e)
{
if (fileStrm != null)
{
try { fileStrm.close(); } catch (IOException ex2) { }
}
System.out.println("Error in file processing: " + e.getMessage());
}
}
public static void processLine(String csvRow)
{
String thisToken = null;
StringTokenizer strTok;
strTok = new StringTokenizer(csvRow, ":");
while (strTok.hasMoreTokens())
{
thisToken = strTok.nextToken();
System.out.print(thisToken + " ");
}
System.out.println("");
}
public static void setLine(State[] state, Location[] location, int stateCount, int locationCount, String line)
{
int i;
state = new State[stateCount];
state = line.split("="); <--- ERROR
for( i = 0; i < stateCount; i++)
{
}
}
public static void writeOneRow(String inFilename)
{
FileOutputStream fileStrm = null;
PrintWriter pw;
try
{
fileStrm = new FileOutputStream(inFilename);
pw = new PrintWriter(fileStrm);
pw.println();
pw.close();
}
catch (IOException e)
{
if (fileStrm != null)
{
try
{
fileStrm.close();
}
catch (IOException ex2)
{}
}
System.out.println("Error in writing to file: " + e.getMessage());
}
}

This error occurs, as it just says 'String[] cannot be converted to State[]'. That is like you wanted to store an Integer into a String, it's the same, because the types don't have a relation to each other (parent -> child).
So if you want to solve your problem you need a method which converts the String[] into a State[]. Something like this:
private State[] toStateArray(String[] strings){
final State[] states = new State[strings.length];
for(int i = strings.length-1; i >= 0; i--){
states[i] = new State(strings[i]); // here you have to decide how to convert String to State
}
return states;
}

Java Read RSS Feed

I am following this Youtube tutorial, but while he gets ALL the headlines from CNN RSS, I only get 1 headline. Why is this so?
my code (same as the one in the tutorial as far as I can see)
import java.net.MalformedURLException;
import java.net.URL;
import java.io.*;
public class ReadRSS {
public static void main(String[] args) {
System.out.println(readRSSFeed("http://rss.cnn.com/rss/edition.rss"));
}
public static String readRSSFeed(String urlAddress){
try{
URL rssUrl = new URL (urlAddress);
BufferedReader in = new BufferedReader(new InputStreamReader(rssUrl.openStream()));
String sourceCode = "";
String line;
while((line=in.readLine())!=null){
if(line.contains("<title>")){
System.out.println(line);
int firstPos = line.indexOf("<title>");
String temp = line.substring(firstPos);
temp=temp.replace("<title>","");
int lastPos = temp.indexOf("</title>");
temp = temp.substring(0,lastPos);
sourceCode +=temp+ "\n" ;
}
}
in.close();
return sourceCode;
} catch (MalformedURLException ue){
System.out.println("Malformed URL");
} catch (IOException ioe){
System.out.println("Something went wrong reading the contents");
}
return null;
}
}

CNN's feed format has changed since he made that Youtube video. The code makes the assumption that there is one title tag per line, when actually there are multiple. Something like this should work now:
while ((line = in.readLine()) != null) {
int titleEndIndex = 0;
int titleStartIndex = 0;
while (titleStartIndex >= 0) {
titleStartIndex = line.indexOf("<title>", titleEndIndex);
if (titleStartIndex >= 0) {
titleEndIndex = line.indexOf("</title>", titleStartIndex);
sourceCode += line.substring(titleStartIndex + "<title>".length(), titleEndIndex) + "\n";
}
}
}

Why is the value not printing in the text view?

I'm trying to print '1' or '0' in text view if it passes the if statements. I ran it in the debug mode, and it all works, but it is not printing in the text view. How do I fix this I tried a lot of stuff, but I'm still stuck.
public class Readcsv {
private static final String FILE_DIR = "/Users/Me/Downloads";
private static final String FILE_TEXT_NAME = ".csv";
public static void main(String [] args) throws Exception{
PrintWriter writer = new PrintWriter("/users/Me/Documents/Test.txt", "UTF-8");
int i=-1;
BufferedReader br = null;
String line = "";
String cvsSplitBy = ",";
//Find Number of Files
String[] list = new Readcsv().FileCount(FILE_DIR, FILE_TEXT_NAME);
System.out.println("Total Files = " + list.length);
while(i++ < list.length){
System.out.println("Loop Count = " + i);
try {
br = new BufferedReader(new FileReader("/users/Tanuj/Downloads/" + list[i]));
while ((line = br.readLine()) != null) {
// use comma as separator
String[] strRecord = line.split(cvsSplitBy);
if (!strRecord[0].equals("timestampMs")){
int c = Integer.parseInt(strRecord[4]);
int e = Integer.parseInt(strRecord[5]);
if(c>e){
writer.print("1");
}
else{
writer.print("0");
}
break;
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
} //End of while
writer.close();
} //End of Main
public String[] FileCount(String folder, String ext) {
GenericExtFilter filter = new GenericExtFilter(ext);
File dir = new File(folder);
if(dir.isDirectory()==false){
System.out.println("Directory does not exists : " + FILE_DIR);
return null;
}
// list out all the file name and filter by the extension
String[] list = dir.list((FilenameFilter) filter);
return list;
}
// inner class, generic extension filter
public class GenericExtFilter implements FilenameFilter {
private String ext;
public GenericExtFilter(String ext) {
this.ext = ext;
}
public boolean accept(File dir, String name) {
return (name.endsWith(ext));
}
}
}

have you tryed BufferedWriter?
File file = new File("Test.txt");
FileOutputStream fos = new FileOutputStream(file);
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos));
bw.write("something");
bw.newLine();
bw.close();

Reading file to ArrayList

I'm trying to write a .dat file to an ArrayList. The file contains lines formatted like this : #name#,#number#.
Scanner s = new Scanner(new File("file.dat"));
while(s.hasNext()){
String string = s.next();
names.add(string.split(",")[0];
numbers.add(Integer.parseInt(string.split(",")[1];
}
If I check if it runs with printing, all I get is the first line.

With standard Java libraries (full code example):
BufferedReader in = null;
List<String> myList = new ArrayList<String>();
try {
in = new BufferedReader(new FileReader("myfile.txt"));
String str;
while ((str = in.readLine()) != null) {
myList.add(str);
//Or split your read string here as you wish.
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (in != null) {
in.close();
}
}
With other common libraries:
A one-liner with commons-io:
List<String> lines = FileUtils.readLines(new File("/path/to/file.txt"), "utf-8");
The same with guava:
List<String> lines =
Files.readLines(new File("/path/to/file.txt"), Charset.forName("utf-8"));
Then you can iterate over the read lines and split each String to your desired ArrayLists.

Instead of using a Scanner, use a BufferedReader. The BufferedReader provides a method to read one line at a time. Using this, you can process every line individually by splitting them (line.split(",")) , stripping the trailing hashes, then pushing them into your ArrayLists.

This is how I read a file and turn it into a arraylist
public List<String> readFile(File file){
try{
List<String> out = new ArrayList<String>();
BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String line;
while((line = reader.readLine()) != null){
if(line != null){
out.add(line);
}
}
reader.close();
return out;
}
catch(IOException e){
}
return null;
}
Hope it helps.

May be this is lengthy way but works:
text file:
susheel,1134234
testing,1342134
testing2,123455
Main class:
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
public class Equal {
public static void main(String[] args) {
List<Pojo> data= new ArrayList<Pojo>();
String currentLine;
try {
BufferedReader br = new BufferedReader(new FileReader("E:\\test.dat"));
while ((currentLine = br.readLine()) != null) {
String[] arr = currentLine.split(",");
Pojo pojo = new Pojo();
pojo.setName(arr[0]);
pojo.setNumber(Long.parseLong(arr[1]));
data.add(pojo);
}
for(Pojo i : data){
System.out.print(i.getName()+" "+i.getNumber()+"\n");
}
} catch (Exception e) {
System.out.print(e.getMessage());
}
}
}
POJO class:
public class Pojo {
String name;
long number;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public long getNumber() {
return number;
}
public void setNumber(long number) {
this.number = number;
}
}

read and write text and changing at only one column

my text
is like that
SEHiR;iL;iLCE;Tip;22356
S SI n;ISTA;ANK;A:S;22356
K K n;IS:TA;BB;B:S;22356
A A b;IS.TA;CC;DK;22356
G S b;ISTA;DD;O:P;22356
I want to change TIP column. I want to put "." instead of ":" for only Tıp column which include A:S,B:S etc.. And I want to write line before changing and after changing to csv. How can I do that? I write something but it has problem at
if(eD.tip.contains(":")) part because it dont continue to hS.Add(eD)
endeks.put("", hS); ı don’t want use “” string.
I do not have to use HasMap I could not write output what I want..
ı expected this output
S SI n;ISTA;ANK;A:S;22356
S SI n;ISTA;ANK;A.S;22356
K K n;IS:TA;BB;B:S;22356
K K n;IS:TA;BB;B.S;22356
G S b;ISTA;DD;O:P;22356
G S b;ISTA;DD;O.P;22356
public class MaliyeVknmDegil {
static class EndeksDegeri {
String sirket ;
String sehir;
String ilce;
String tip;
int numara;
}
static HashMap<String,HashSet<EndeksDegeri>> endeks = new HashMap<String, HashSet<EndeksDegeri>>();
static PrintWriter pW;
static EndeksDegeri eD = new EndeksDegeri();
static String satır;
private static PrintWriter pW2;
public static void main(String[] args) {
FileInputStream fIS;
FileOutputStream fOS;
try {
fIS = new FileInputStream("C:\\deneme\\DENEME.csv");
Reader r = new InputStreamReader(fIS, "UTF-8");
BufferedReader bR = new BufferedReader(r);
fOS = new FileOutputStream("c:\\yazdirilan\\deneme.csv");
Writer w = new OutputStreamWriter(fOS, "UTF-8");
pW2 = (new PrintWriter(w));
String satır;
String[] eleman;
while ((satır = bR.readLine()) != null) {
eleman = satır.split(";");
if(satır.contains(":")){
pW2.write(satır);
}
HashSet<EndeksDegeri> hS = new HashSet<EndeksDegeri>();
for (int i = 0; i < eleman.length; i++) {
// alteleman=eleman[i].split(" ");
EndeksDegeri eD = new EndeksDegeri();
eD.sirket = eleman[0];
eD.sehir = eleman[1];
eD.ilce = eleman[2];
if(eD.tip.contains(":")){
eD.tip.replaceAll(":", ".");
eD.tip = eleman[3];
}
eD.numara = Integer.parseInt(eleman[4]);
hS.add(eD);
}
endeks.put("", hS);
}
bR.close();
// yazdir
HashSet<EndeksDegeri> hS;
for (String s : endeks.keySet()) {
hS = endeks.get(s);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ArrayIndexOutOfBoundsException e) {
e.printStackTrace();
}
}// main end
}// clas end

package stackoverflow;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
public class TipChange {
private static String inputPath = "input.csv";
private static String outputPath = "output.csv";
private static BufferedReader bufferedReader;
private static PrintWriter printWriter;
public static void main(String[] args) {
try {
FileInputStream inputStream = new FileInputStream(inputPath);
Reader reader = new InputStreamReader(inputStream, "UTF-8");
bufferedReader = new BufferedReader(reader);
FileOutputStream outputStream = new FileOutputStream(outputPath);
Writer writer = new OutputStreamWriter(outputStream, "UTF-8");
printWriter = new PrintWriter(writer);
String line;
while ((line = bufferedReader.readLine()) != null) {
EndeksDegeri eD = lineToClass(line);
if (shouldOutput(eD)) {
printWriter.append(classToLine(eD, true));
printWriter.append(classToLine(eD, false));
}
}
} catch (IOException e) {
e.printStackTrace();
}
finally {
try {
bufferedReader.close();
printWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static boolean shouldOutput(EndeksDegeri eD) {
if (!eD.tip.contains(":")) {
return false;
}
return true;
}
private static String classToLine(EndeksDegeri eD, boolean original) {
if (!original) {
eD.tip = eD.tip.replace(":", ".");
}
return eD.sirket.concat(";")
.concat(eD.sehir).concat(";")
.concat(eD.ilce).concat(";")
.concat(eD.tip).concat(";")
.concat(String.valueOf(eD.numara)
.concat("\r\n"));
}
private static EndeksDegeri lineToClass(String line) {
String[] element = line.split(";");
EndeksDegeri endeksDegeri = new EndeksDegeri();
endeksDegeri.sirket = element[0];
endeksDegeri.sehir = element[1];
endeksDegeri.ilce = element[2];
endeksDegeri.tip = element[3];
endeksDegeri.numara = Integer.valueOf(element[4]);
return endeksDegeri;
}
private static class EndeksDegeri {
String sirket ;
String sehir;
String ilce;
String tip;
int numara;
}
}
Sample input:
SSI;ISTA;ANK;A:S;22356
KK;IS:TA;BB;B:S;22356
AA;IS.TA;CC;DK;22356
GS;ISTA;DD;O:P;22356
Generated Output:
SSI;ISTA;ANK;A:S;22356
SSI;ISTA;ANK;A.S;22356
KK;IS:TA;BB;B:S;22356
KK;IS:TA;BB;B.S;22356
GS;ISTA;DD;O:P;22356
GS;ISTA;DD;O.P;22356

Your code will produce a NullPointerException in the line: if(eD.tip.contains(":")){
That is because when a new EndeksDegeri instance is created all its fields are null you cannot call contains() on a null string.
Check the example code below (It writes to the console but it should get you going)
static class EndeksDegeri {
String sirket;
String sehir;
String ilce;
String tip;
int numara;
// I have added this method for convenience to write to the output
public String toString() {
return sirket + ":" + sehir + ":" + ilce + ":" + tip + ":" + numara;
}
}
while ((satir = bR.readLine()) != null) {
eleman = satir.split(";");
boolean found = false;
EndeksDegeri eD = new EndeksDegeri();
// first set all fields to not get exception
eD.sirket = eleman[0];
eD.sehir = eleman[1];
eD.ilce = eleman[2];
eD.tip = eleman[3];
eD.numara = Integer.parseInt(eleman[4]);
// check if the line contains ":"
if (eD.tip.contains(":")) {
// If yes, write the original line first
System.out.println(eD.toString());
// Change the record
eD.tip = eD.tip.replaceAll(":", ".");
found = true;
}
if (found) {
// write the corrected line now
System.out.println(eD.toString());
}
}
// Will print only the lines with ":" and its correct version
SSI:ISTA:ANK:A:S:22356
SSI:ISTA:ANK:A.S:22356
KK:IS:TA:BB:B:S:22356
KK:IS:TA:BB:B.S:22356
GS:ISTA:DD:O:P:22356
GS:ISTA:DD:O.P:22356