Develop Reference

Implementing "Move" function with VFS

I'm trying to implement a wrapped "move" function with Xodus, but something is not working out right:
#Override
public boolean move(String appId, String name, String targetName) {
final boolean[] success = new boolean[1];
final Environment env = manager.getEnvironment(xodusRoot, appId);
final VirtualFileSystem vfs = manager.getVirtualFileSystem(env);
env.executeInTransaction(
new TransactionalExecutable() {
#Override
public void execute(#NotNull final Transaction txn) {
File file = vfs.openFile(txn, name, false);
InputStream input = vfs.readFile(txn, file);
if(input != null) {
File targetFile = vfs.openFile(txn, targetName, true);
DataOutputStream output = new DataOutputStream(vfs.writeFile(txn, targetFile));
try {
output.write(ByteStreams.toByteArray(input));
} catch (IOException e) {
e.printStackTrace();
}
vfs.deleteFile(txn, name);
success[0] = true;
}
}
});
// vfs.shutdown();
// env.close();
return success[0];
}
The problem is the file gets moved but the byte array is not getting copied, not sure if the problem is because of multiple VFS operation in the same transaction. Can someone give me a hint of why the bytes from the source file are not getting copied properly?

Looks like you are trying to implement another version of VirtualFileSystem.renameFile(..).

Pass in file text into hashmap

I am having a bit of an issues trying to pass in a file read by my program and sorted accordantly. I am not used to working with files, and i ran out of ideas as to how this could be achieved.
/////////////////////////////////////// class reads file ///////////////////////////////////
import java.io.*;
public class InFileReader {
private BufferedReader inputStream = null;
private String fileLine;
private StringBuilder sb;
public String getFile(File fileRead) throws FileNotFoundException,
IOException {
inputStream = new BufferedReader(new FileReader(fileRead)); //reads files
sb = new StringBuilder();
while((fileLine = inputStream.readLine()) != null){//keep reading lines in file till there is none
sb.append(fileLine).append("\n");
}
return sb.toString(); //returns StringBuffer read values in String form
}
}
///////////////////////////////////////////////////// end of read file class ///////////////////////
public void getFile(File fileRead) throws FileNotFoundException,
IOException {
try {
String input = fileReader.getFile(fileRead.getAbsoluteFile());
HashMap<Integer, Thing.Ship> hashmap = new HashMap<>();
while (!input.isEmpty()) { // as long as there is data in the file keep looping
Scanner sc = new Scanner(input); // scan file
if (!input.startsWith("//")) { // take out "//" from directory
String type = "";
if (sc.hasNext()) { // if there are character lines get next line
type = sc.next();
}
if (type.equalsIgnoreCase("port")) { // looks for "port"
world.assignPort(new Thing.SeaPort(sc)); // assigns value to Seaport
} else if (type.equalsIgnoreCase("dock")) {
world.assignDock(new Thing.Dock(sc));
} else if (type.equalsIgnoreCase("ship")) {
Thing.Ship s = new Thing.Ship(sc);
hashmap.put(s.getIndex(), s);
world.assignShip(s);
} else if (type.equalsIgnoreCase("pship")) {
Thing.Ship s = new Thing.PassengerShip(sc);
hashmap.put(s.getIndex(), s);
world.assignShip(s);
} else if (type.equalsIgnoreCase("cship")) {
Thing.Ship s = new Thing.CargoShip(sc);
hashmap.put(s.getIndex(), s);
world.assignShip(s);
} else if (type.equalsIgnoreCase("person")) {
world.assignPerson(new Thing.Person(sc));
}
}
}
//inputOut.setText(type);
inputOut.setText(world.toString());
} catch (Exception e) {
System.out.println(e + "-----");
}
}
Here fileRead knows where to find the file to be read "C:\Users\abe\IdeaProjects\CreateSeaPortDataFile\src\text.txt"
public void getFile(File fileRead) throws FileNotFoundException,
IOException {
this is where things just fall apart:
String input = fileReader.getFile(fileRead.getAbsoluteFile());
My intent here is to pass the location of the file so that the getFile class can read it and then be sorted into the hashmap.
again i am not familiar with how to work with file, any suggestion or comment would be greatly appreciated.
thank you in advanced.

If you get a FileNotFoundException then the file was not found.
You say the filename was "C:\Users\abe\IdeaProjects\CreateSeaPortDataFile\src\text.txt".
If you type that name in the code you must escape the backslash:
"C:\\Users\\abe\\IdeaProjects\\CreateSeaPortDataFile\\src\\text.txt".

Comparing ArrayList with user input

I have been trying to compare the file content with user input. The program is reading from a specific file and it checks against the user's string input. I am having trouble comparing the ArrayList with the user input.
public class btnLoginListener implements Listener
{
#Override
public void handleEvent(Event arg0)
{
//variables for the class
username = txtUsername.getText();
password = txtPassword.getText();
MessageBox messageBox = new MessageBox(shell, SWT.OK);
try {
writeFile();
messageBox.setMessage("Success Writing the File!");
} catch (IOException x)
{
messageBox.setMessage("Something bad happened when writing the file!");
}
try {
readFile("in.txt");
} catch (IOException x)
{
messageBox.setMessage("Something bad happened when reading the file!" + x);
}
if (username.equals(names))
{
messageBox.setMessage("Correct");
}
else
{
messageBox.setMessage("Wrong");
}
messageBox.open();
}
}
private static void readFile(String fileName) throws IOException
{
//use . to get current directory
File dir = new File(".");
File fin = new File(dir.getCanonicalPath() + File.separator + fileName);
// Construct BufferedReader from FileReader
BufferedReader br = new BufferedReader(new FileReader(fin));
String line = null;
while ((line = br.readLine()) != null)
{
Collections.addAll(names, line);
}
br.close();
}

I am assuming you are trying to check whether an element exists in the list. If yes, then you need to use contains method, here's the Javadoc.
So, instead of using if (username.equals(names)), you can use if (names.contains(username)).
Apart from this, you should make the following changes:
Don't read the file every time an event is called. As you are reading a static file, you can read it once and store it in an ArrayList.
Make variables username and password local.
Remove writeFile() call unless it's appending/writing dynamic values on each event.

Best approach of reading data from text file and adding it to arraylist in android

I am working on a project to get into android development, having some knowledge of java before I am thinking of reading data from a text file, which will be formatted like this;
Type: House
Image link: www.bit.ly/image1
Name: Black
Download Link: www.bit.ly/image1download
----------
Type: Car
Image link: www.bit.ly/image2
Name: yellow
Download Link: www.bit.ly/image2download
----------
Type: Backyard
Image link: www.bit.ly/image3
Name: Green
Download Link: www.bit.ly/image3download
----------
Type: Window
Image link: www.bit.ly/image4
Name: Solid
Download Link: www.bit.ly/image4download
----------
Type: Table
Image link: www.bit.ly/image5
Name: Brown
Download Link: www.bit.ly/image5download
----------
The data contains 4 pieces of information per set, Type, Image, Name and Download. I need a way of reading this and saving/writing it to a arraylist which I then can display in a listview that I will have on my app. (I am currently looking at tutorials on creating listview, if you know any useful tutorials please let me know)
Arraylist <String> data = new ArrayList<String>();
Data.add(“House”,” www.bit.ly/image1”,”black”,”www.bit.ly/image1download”);
Data.add(“Car”,” www.bit.ly/image2”,”yellow”,” www.bit.ly/image2download”);
……..
……..
In reality there will be a lot more data then just 5 sets , so I want to use for loop to loop through each data data and add it to the data arraylist.
I am not sure how I can approach this, any help is welcomed, I am really stuck. Please let me know if I have not explained my question properly.
EDITED:
Would this be the correct way of reading data from a textfile?
Scanner content = new Scanner(new File("Data.txt"));
ArrayList<String> data = new ArrayList<String>();
while (content.hasNext()){
data.add(content.next());
}
content.close();
Or is this another way in android

Before start go through this link for reading
How can I read a text file in Android?
Use PoJo Models for your needs,
Create a PoJo class like this
public class Film {
private String filmName;
private String mainStar;
public String getFilmName() {
return filmName;
}
public void setFilmName(String filmName) {
this.filmName = filmName;
}
public String getMainStar() {
return mainStar;
}
public void setMainStar(String mainStar) {
this.mainStar = mainStar;
}
}
Create ArrayList
private ArrayList<Film > filmArray=new ArrayList<Film>();
Store Each arraylist with instance of your PoJo class like this
for(int i=0;i<sizei++)
{
Film film=new Film();
film.setFilmName("your value");
film.setMainStar("your value");
filmArray.add(film);
}
and then access list of values in arraylist of PoJo class in filmArray list.
Simple and elegant solution.

Here is the parser
public class FileParser {
private static final String DATA_TERMINATION = "----------";
private static final String TYPE="Type";
private static final String IMAGE="Image link";
private static final String NAME= "Name";
private static final String DWNLD_LNK= "Download Link";
public static void main(String[] args) {
FileParser parser = new FileParser();
try {
for(Data d:parser.parseDataFile(new File("F:\\data.txt"))){
System.out.println(TYPE+":"+d.getType());
System.out.println(IMAGE+":"+d.getImage());
System.out.println(NAME+":"+d.getName());
System.out.println(DWNLD_LNK+":"+d.getLink());
System.out.println(DATA_TERMINATION);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public List<Data> parseDataFile(File input) throws Exception{
List<Data> output =null;
List<String> fileOp= null;
try {
validateInput(input);
fileOp = readFile(input);
output = parseData(fileOp);
} catch (Exception e) {
throw e;
}
return output;
}
private List<Data> parseData(List<String> fileOp) {
List<Data> output =null;
output = new ArrayList<Data>();
Data data;
data = new Data();
for(String line:fileOp){
if(DATA_TERMINATION.equalsIgnoreCase(line)){
output.add(data);
data = new Data();
}else{
parseField(data,line);
}
}
return output;
}
private void parseField(Data data, String line) {
StringTokenizer tokenzr = new StringTokenizer(line,":");
if(tokenzr.countTokens() !=2){
System.out.println("Cant parse line"+line);
}else{
switch (tokenzr.nextToken()) {
case TYPE:
data.setType(tokenzr.nextToken());
break;
case IMAGE:
data.setImage(tokenzr.nextToken());
break;
case NAME:
data.setName(tokenzr.nextToken());
break;
case DWNLD_LNK:
data.setLink(tokenzr.nextToken());
break;
default:
break;
}
}
}
private List<String> readFile(File input) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(input)));
String line = null;
List<String> op = new ArrayList<String>();
try {
while((line = reader.readLine()) != null){
op.add(line);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw e;
}
return op;
}
private void validateInput(File input) throws Exception {
if(input == null){
throw new Exception("Null input");
}else if(!input.exists() || !input.isFile() || !input.canRead() ) {
throw new Exception("File not readable");
}
}
}

Do this way define a setter getter class to hold and return values like this :
Data.class
public class Data {
String type,Image,Name,Link ;
public Data() {
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getImage() {
return Image;
}
public void setImage(String image) {
Image = image;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getLink() {
return Link;
}
public void setLink(String link) {
Link = link;
}
}
using for loop set data in a arraylist
Arraylist <Data> arrayListData = new ArrayList<Data>();
for(int i=0;i<arrayListData .size();i++){
Data data=new Data();
data.setType("");
...
...
...
arrayListData.add(data);
}
and to fetch data from arraylist
String type= arrayListData.get(position).getType();
Updated :
read .txt file like this , I am assuming your text file is saved in sdcard of device :
public void readfile() {
StringBuilder text = new StringBuilder();
File sdcard = Environment.getExternalStorageDirectory();
ArrayList<Data> arrayList=new ArrayList<Data>();
//Get the text file
File file = new File(sdcard,"textfile.txt");
//Read text from file
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
Data data=new Data();
while ((line = br.readLine()) != null) {
text.append(line);
text.append('\n');
if(line.contains(":")){
int index=line.indexOf(":");
String s=line.substring(index+1).trim();
if(line.contains("Type")){
data.setType(s);
}
if(line.contains("Image")){
data.setImage(s);
}
if(line.contains("Name")){
data.setName(s);
}
if(line.contains("Download")){
data.setLink(s);
}
}
if(line.contains("-")){
arrayList.add(data);
data=new Data();
}
}
System.out.println(text);
br.close();
}
catch (IOException e) {
e.printStackTrace();
}
}

Insert selected file to FileReader

i want to take selected file in another class and insert it to other class in method doit() for variable in in FileReader().
how can i insert in method doit(), in class Element,not this file "D:\Probe.txt",
public void doit() {
try {
in = new BufferedReader(new FileReader("D:\\Probe.txt"));
out = new StreamResult("D:\\data.xml");
initXML();
String str;
while ((str = in.readLine()) != null) {
process(str);
}
in.close();
closeXML();
} catch (Exception e) {
e.printStackTrace();
}
}
Notably this file, that in patch variable from class Dialog,
`
if (cmd.equals("Quelldatei auswählen")) {
JFileChooser fileChooser = new JFileChooser();
fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
int ret = fileChooser.showDialog(this, "auswählen");
if (ret == JFileChooser.APPROVE_OPTION) {
File patch = fileChooser.getSelectedFile();
contentPane.add(new JLabel("Quelldatei ist: " + patch));
}

I understood your problem like you want the file in your doit() method without using the BufferedReader inside this method?
if im right, try this:
Save your file in a File Object and give this object as a parameter to your doit() method like:
public void doit(File file){
...
}