Develop Reference

How do I read files as a object or is there a better solution to this? Please see code bellow for context

So in my java class, we need to read this file and somehow converts its content into an object
import java.util.Scanner;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
public class Calendar {
public Appointment[] appointments;
Calendar()
{
appointments = null;
}
Calendar(int capacity, String filename)
{
Appointment[] appointments = new Appointment[capacity];
//you can see that appointments is an Appointment object
readCalendarFromFile(filename);}
private void readCalendarFromFile(String fileName){
Scanner fileRead = null;
try
{
fileRead = new Scanner(new FileInputStream("appointments.txt"));
for(int r = 0; r < 30; r++)
appointments[r]= fileRead.nextLine(); ----> This is where I am getting my error from as I cannot convert String into an object. Is there a way that I can pass this
fileRead.close();
}
catch (FileNotFoundException fe)
{
fe.printStackTrace();
System.err.println("Unable to open the file " + fileName + " for reading.");
}
}
}
Is there any way that I can convert filetext into an object or do I have to do something else with it? I have to make an appointment an object so I can't change it into anything else sadly.

You have to have a class Appointment somewhere, and what you are trying to do is add an object of the type Appointment to the array appointments, based on the info you get from the text file, right?
So, you have your for loop that reads every line from the text file, and then you need to create instances of Appointment for each line.
The class Appointment has some kind of constructor, that you need to call to create a new object (read: "a new instance") from it.
Let's assume it looks like this:
public Appointment(String title, String time, String location) {
this.title = title;
this.time = time;
this.location = location;
}
Let's also assume that every line in the file appointments.txt is formatted in the following way:
<Title>, <Time>, <Location>
Which means, that you would have to parse the line that you read from the file by splitting it (the delimiter in this case would be the ",". Just do a quick research on the internet on how to split Strings in Java, it's pretty easy actually.
When you have all the bits of information in separate variables, you have to call the constructor of Appointment, to create a new appointment that you can then add to your array. Assuming that you have three Strings with the title, the time and the location of the appointment (or whatever info you have in the text file), this would look like this:
try{
fileRead = new Scanner(new FileInputStream("appointments.txt"));
int counter = 0;
while(fileRead.hasNext()) {
String lineRead = fileRead.nextLine();
// here comes the parsing of the line into three String variables
appointments[counter] = new Appointment(title, time, location);
fileRead.close();
}
} catch(FileNotFoundException ex) {
// Do some exception handling in here, or just print the stacktrace
}
The line I want you to pay the most attention to is the Line, where it says new Appointment(title, time, location). The difference between this and the code that you posted is, that here I create a new object of the type Appointment, that corresponds with the type of the array you created earlier, in the line Appointment[] appointments = new Appointment[capacity].
You tried to directly add a String to the array, although you declared an array of the type Appointment, not of the type String.
You should read up on the topic of objects in Java in general, and what constructors are, what they do and how you use them.
For example, this topic gets explained really well and exhaustive in the official Java tutorials from Oracle (the company that develops the Java Language). I linked you the specific section that talks about constructors, but I would suggest that you read at least the whole chapter and everything before it that helps you understand what they actually talk about.
Hope this helps :)

Can I Change value string name in String.xml using edittext? [duplicate]

I have declared a string in my strings.xml file , and using it in my activity as R.string.compose_title. (setting it as title i.e. setTitle(R.id.compose_title)). Now in some case I want to edit the string and then use it to set the title . How can I do this ?
P.S. I need to change value of a single string only , So declaring a new strings.xml for each case(which are variable depending upon the user) using localization seems to be a lil inefficient .

One thing what you have to understand here is that, when you provide a data as a Resource, it can't be modified during run time. For example, the drawables what you have in your drawable folder can't be modified at run time. To be precise, the "res" folder can't be modified programatically.
This applies to Strings.xml also, i.e "Values" folder. If at all you want a String which has to be modified at runtime, create a separate class and have your strings placed in this Class and access during run time. This is the best solution what I have found.

example howto:
how? by changing one variable reference to other reference
usage:
setRColor(pl.mylib.R.class,"endColor",pl.myapp.R.color.startColor);
// override app_name in lib R class
setRString(pl.mylib.R.class,"app_name",pl.myapp.R.string.app_name);
base methods:
public static void setRColor(Class rClass, String rFieldName, Object newValue) {
setR(rClass, "color", rFieldName, newValue);
}
public static void setRString(Class rClass, String rFieldName, Object newValue) {
setR(rClass, "string", rFieldName, newValue);
}
// AsciiStrings.STRING_DOLAR = "$";
public static void setR(Class rClass, String innerClassName, String rFieldName, Object newValue) {
setStatic(rClass.getName() + AsciiStrings.STRING_DOLAR + innerClassName, rFieldName, newValue);
}
helper methods :
public static boolean setStatic(String aClassName, String staticFieldName, Object toSet) {
try {
return setStatic(Class.forName(aClassName), staticFieldName, toSet);
} catch (ClassNotFoundException e) {
e.printStackTrace();
return false;
}
}
public static boolean setStatic(Class<?> aClass, String staticFieldName, Object toSet) {
try {
Field declaredField = aClass.getDeclaredField(staticFieldName);
declaredField.setAccessible(true);
declaredField.set(null, toSet);
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
#bradenV2 My app is supporting many languages , so I wanted to take a
string from my strings.xml that's currently in use and change that ,
and then use that one – atuljangra Mar 12 '12 at 22:04
ps the above solution is good for example when u want to inject some data in already compiled lib/jar. But if u want localize strings just make folder under res per LANG CODE like values-CC where cc is lang code (values-de,values-cs) etc
then u have 2 choices:
"build in" system dependent language selection - based on device selected lang
via create resources for configuration - you decide which lang show
like this:
configuration = new Configuration(resources.getConfiguration());
configuration.setLocale(targetLocale);
String localized = Context.createConfigurationContext(configuration)
.getResources()
.getString(resourceId);

I don't think you can programmatically customize the R class as it is built by ADT automatically.

I had a situation like this, where one of my strings.xml values had some dynamic piece of it. I set up the strings.xml with a "replacement text" (something like %%REPLACEMENT_EMAIL%%), and when I wanted to use that string programatically, I retrieved the string value of the resource, and replaced instances of that replacement text with the dynamic value (e.g. input by the user).
To be honest, my app has not been localized yet, but I'm still attempting to follow best practices w.r.t. not hardcoding any strings.

Use SharedPreferences instead of a Java class. It will give you more versatility if you decide to take values from the outside (web). Filling Java class in runtime can be useless offline. In case of SharedPreferences you have to ensure they are loaded only once, during app's first start, and then updated only by manual request, as previous import will be used.
myActivity.getSharedPreferences("com.example.imported",0)
.edit()
.putString("The news",getTheNews())
.apply();

Maybe you want to "modify" the string.xml so when it is required by the activity again it uses the new value, for example to keep a new dynamic title after screen rotation.
First, you can't modify the resource. It's already compiled. You can't modify the R class (what for?) all it's atributes are "final".
So, for the example above you can use onSaveInstanceState() and onRestoreInstanceState() for those properties you wanna keep on display.

According to my knowledge, you can't change resource value(R class value) while app running. why don't try to store on shared preference? I recommend you to use shared preference

I used below method to get the key-value pairs from the API and storing it in HashMap globally. If the key value is not found in HashMap then I will search that key in strings.xml file. It will achieve the purpose of dynamically changing the value of key.
public String getAppropriateLangText(String key) {
String value = "";
try {
HashMap<String, String> HashMapLanguageData HashMapLanguageData = gv.getHashMapLanguageData();
value = HashMapLanguageData.get(key);//Fetching the value of key from API
if (value == null || value.length() == 0) { //If Key value not found, search in strings.xml file
String packageName = getPackageName();
int resId = getResources().getIdentifier(key, "string", packageName);
value = getString(resId);
}
} catch (Exception e) {
value = "";
}
return value;
}

How to get the distinct element from mediastore by java

I am trying to get the file names of all the audio files but I am getting same file names for multiple songs
1.I cannot use DISTINCT key word as I am getting the file names from DATA .
2.I am using the Mediastore.Files So the select it takes MEDIA_TYPE so this way is also not possible .
3 .I want to get the Parent value as distinct not the repeating value .
So the only way is by doing in java .I followed the method given here but I am not able to set
Here is a piece of my code
if (audioCursor.moveToFirst()) {
do {
int filetitle = audioCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.TITLE);
int file_id = audioCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns._ID);
int fileparent = audioCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.PARENT);
int filedata = audioCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATA);
Mediafileinfo info = new Mediafileinfo();
info.setData(new File(new File(audioCursor.getString(filedata)).getParent()).getName());
info.setTitle(audioCursor.getString(filetitle));
info.set_id(audioCursor.getString(file_id));
info.setParent(audioCursor.getString(fileparent));
audioList.add(info);
} while (audioCursor.moveToNext());
}
How I can get the non repeating elements?? For more info mediastore.file
I am adding the data in Mediafileinfo class which contain getter and setter.

I want to get the Parent value as distinct not the repeating value .
Alright, you could use a HashSet<String> to maintain a list of seen MediaStore.Files.FileColumns.PARENT values.
Not sure what was wrong with the SQL approach, though.
HashSet<String> seenParents = new HashSet<String>();
if (audioCursor.moveToFirst()) {
final int fileparent = audioCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.PARENT);
do {
String parent = audioCursor.getString(fileparent);
Mediafileinfo info = new Mediafileinfo();
// bla...
info.setParent(parent);
if (!seenParents.contains(parent)) { // prevents dups
seenParents.add(parent);
audioList.add(info);
}
// end loop

JHDF5 - How to avoid dataset being overwritten

I am using JHDF5 to log a collection of values to a hdf5 file. I am currently using two ArrayLists to do this, one with the values and one with the names of the values.
ArrayList<String> valueList = new ArrayList<String>();
ArrayList<String> nameList = new ArrayList<String>();
valueList.add("Value1");
valueList.add("Value2");
nameList.add("Name1");
nameList.add("Name2");
IHDF5Writer writer = HDF5Factory.configure("My_Log").keepDataSetsIfTheyExist().writer();
HDF5CompoundType<List<?>> type = writer.compound().getInferredType("", nameList, valueList);
writer.compound().write("log1", type, valueList);
writer.close();
This will log the values in the correct way to the file My_Log and in the dataset "log1". However, this example always overwrites the previous log of the values in the dataset "log1". I want to be able to log to the same dataset everytime, adding the latest log to the next line/index of the dataset. For example, if I were to change the value of "Name2" to "Value3" and log the values, and then change "Name1" to "Value4" and "Name2" to "Value5" and log the values, the dataset should look like this:
I thought the keepDataSetsIfTheyExist() option to would prevent the dataset to be overwritten, but apparently it doesn't work that way.
Something similar to what I want can be achieved in some cases with writer.compound().writeArrayBlock(), and specify by what index the array block shall be written. However, this solution doesn't seem to be compatible with my current code, where I have to use lists for handling my data.
Is there some option to achieve this that I have overlooked, or can't this be done with JHDF5?

I don't think that will work. It is not quite clear to me, but I believe the getInferredType() you are using is creating a data set with 2 name -> value entries. So it is effectively creating an object inside the hdf5. The best solution I could come up with was to read the previous values add them to the valueList before outputting:
ArrayList<String> valueList = new ArrayList<>();
valueList.add("Value1");
valueList.add("Value2");
try (IHDF5Reader reader = HDF5Factory.configure("My_Log.h5").reader()) {
String[] previous = reader.string().readArray("log1");
for (int i = 0; i < previous.length; i++) {
valueList.add(i, previous[i]);
}
} catch (HDF5FileNotFoundException ex) {
// Nothing to do here.
}
MDArray<String> values = new MDArray<>(String.class, new long[]{valueList.size()});
for (int i = 0; i < valueList.size(); i++) {
values.set(valueList.get(i), i);
}
try (IHDF5Writer writer = HDF5Factory.configure("My_Log.h5").writer()) {
writer.string().writeMDArray("log1", values);
}
If you call this code a second time with "Value3" and "Value4" instead, you will get 4 values. This sort of solution might become unpleasant if you start to have hierarchies of datasets however.

To solve your issue, you need to define the dataset log1 as extendible so that it can store an unknown number of log entries (that are generated over time) and write these using a point or hyperslab selection (otherwise, the dataset will be overwritten).
If you are not bound to a specific technology to handle HDF5 files, you may wish to give a look at HDFql which is an high-level language to manage HDF5 files easily. A possible solution for your use-case using HDFql (in Java) is:
public class Example
{
public Class Log
{
String name1;
String name2;
}
public boolean doSomething(Log log)
{
log.name1 = "Value1";
log.name2 = "Value2";
return true;
}
public static void main(String args[])
{
// declare variables
Log log = new Log();
int variableNumber;
// create an HDF5 file named 'My_Log.h5' and use (i.e. open) it
HDFql.execute("CREATE AND USE FILE My_Log.h5");
// create an extendible HDF5 dataset named 'log1' of data type compound
HDFql.execute("CREATE DATASET log1 AS COMPOUND(name1 AS VARCHAR, name2 AS VARCHAR)(0 TO UNLIMITED)");
// register variable 'log' for subsequent usage (by HDFql)
variableNumber = HDFql.variableRegister(log);
// call function 'doSomething' that does something and populates variable 'log' with an entry
while(doSomething(log))
{
// alter (i.e. extend) dataset 'log1' to +1 (i.e. add a new row)
HDFql.execute("ALTER DIMENSION log1 TO +1");
// insert (i.e. write) data stored in variable 'log' into dataset 'log1' using a point selection
HDFql.execute("INSERT INTO log1(-1) VALUES FROM MEMORY " + variableNumber);
}
}
}

Bukkit plugin - check if specific data from a file exists, and declare it

I'm having an issue with a bukkit plugin I'm updating. In what I'm doing, when a player uses a bed, it saves the following data to a file named beds.yml:
ThePlayersUsername:
X: (double)
Y: (double)
Z: (double)
world: worldName
When the plugin is initialized, I need to declare a few variables, because they are used later on in the code.
Player p = (Player)sender;
String dn = p.getDisplayName();
dn = ChatColor.stripColor(dn);
double x = (Double) yml.get(dn + ".x");
double y = (Double) yml.get(dn + ".y");
double z = (Double) yml.get(dn + ".z");
World bw = Bukkit.getWorld((yml.get(dn + ".world").toString()));
Location l = new Location(bw, x, y, z);
I can't do this if they don't exist, but, I can't reset to any defaults because new items get added to the config each time someone enters a bed, and all data is user-specific.
How would I go about checking if the player has some data in the config, if not, telling them to sleep in a bed, and when they do have data in the config, how to declare it so they can use a command to teleport using data from the config. Thanks.

Create 2 list or array:
-The online players
-The players in the config
A simple string list is do the magic just store the names. Then compare them. Something like that:
List<String> online_players = new List<String>();
//fill list code here
List<String players_in_config = new List<String>();
//fill list code here
List<String> output = new List<String>();
for(String s : online_players){
for(String a : players_in_config){
if(s.equals(a)){
output.add(s);
break;
}
}
}
//and now output contains the names of the players that online and have a bed in the config

You are going to want to use a Map here. Maps are a data structure that creates key-value pairs for your data. You can ask a Map for the data associated with a given key and you will get the value you put into it, or null if they key was not found.
Your map would look something like this:
private Map<Player, Location> bedLocations = new HashMap<Player, Location>();
We are going to store this data inside your JavaPlugin class since it needs access inside your listener and command handler. You will also need a way to get this Map from within your listener. An accessor method will do the job here. See the below method for how to do this. You will need to do it later as well.
public Map<Player, Location> getBedLocations() {
return bedLocations;
}
In case you were wondering, a HashMap is a type of map that used the int hashCode() method to quicken key value access, but that's a more high level topic that's irrelevant to the issue at hand.
That map should store a key-value pair of all Players currently online that have a bed location associated with them. Since you don't need someone's info until they come online, you shouldn't load out of the configuration yet, but you should still open the configuration like so to prevent reading the file every time. This should be done in the onEnable method.
//Near your map and other class variables
private FileConfiguration bedConfiguration;
//Inside your onEnable
bedConfiguration = YamlConfiguration.loadConfiguration(new File(PLUGIN_VARIABLE.getDataFolder(), "beds.yml"));
Don't forget to store that bedConfiguration in a class variable. Also create an accessor method for it. I would name it getBedConfiguration().
Now you have a loaded configuration and a place to store your data, what next? You need to populate your Map with player data when they join.
Inside your listener, you should write a method to listen for the PlayerJoinEvent. Inside here you will load your player data.
Firstly, we need to get the YML file from our JavaPlugin class.
FileConfiguration bedConfig = plugin.getBedConfiguration();
That will get you the FileConfiguration that you opened up earlier. Now we check to see if the player's data is in the config.
if (bedConfig.isSet(event.getPlayer().getName()) {
//Next section here
}
If the isSet method returns true, then something exists there. Now we load the data.
String playerName = event.getPlayer.getName(); //You can do this above the if statement if you wish.
double x = (Double) bedConfig.get(playerName + ".x");
double y = (Double) bedConfig.get(playerName + ".y");
double z = (Double) bedConfig.get(playerName + ".z");
World bw = Bukkit.getWorld((bedConfig.get(dn + ".world").toString()));
Location loc = new Location(bw, x, y, z);
Your data is loaded! Excellent. Now we store it in the map for later access. First, get the Map from the JavaPlugin class. Then we put our data into the Map.
Map<Player, Location> map = plugin.getBedLocations();
map.put(event.getPlayer(), loc);
The data is in the map! To access it, make sure you get the map first and then call map.get(PLAYER);
Other things that need to be done are... saving the data when a player leaves / the server shuts down and removing the player from the map when they leave (Keeping players in a map is a very bad practice, you can use their name or UUID as a key if you wish to prevent that issue).
To save your Map to the config, you can either change the config whenever a bed location changes, or you can wait and loop over all the Map entries and save them all at the end. To loop over these you can use an advanced for loop.
for(Player player : map.keySet()) {
Location loc = map.get(player);
//save here
}
This will loop over all players in the map and let you access their location with the map.get(player) method.
To remove a player from the map, listen for the PlayerQuitEvent and use map.remove(player); to unload their data. Don't forget to save it first if you don't save it every update.
If you have any questions, please leave a comment. I tried to be very thorough.