Develop Reference

getting first level of categorisation from Notes view

I have a categorized Notes view, let say the first categorized column is TypeOfVehicle the second categorized column is Model and the third categorized column is Manufacturer.
I would like to collect only the values for the first category and return it as json object:
I am facing two problems:
- I can not read the value for the category, the column values are emptry and when I try to access the underlying document it is null
the script won't hop over to the category/sibling on the same level.
can someone explain me what am I doing wrong here?
private Object getFirstCategory() {
JsonJavaObject json = new JsonJavaObject();
try{
String server = null;
String filepath = null;
server = props.getProperty("server");
filepath = props.getProperty("filename");
Database db;
db = utils.getSession().getDatabase(server, filepath);
if (db.isOpen()) {
View vw = db.getView("transport");
if (null != vw) {
vw.setAutoUpdate(false);
ViewNavigator nav;
nav = vw.createViewNav();
JsonJavaArray arr = new JsonJavaArray();
Integer count = 0;
ViewEntry tmpentry;
ViewEntry entry = nav.getFirst();
while (null != entry) {
Vector<?> columnValues = entry.getColumnValues();
if(entry.isCategory()){
System.out.println("entry notesid = " + entry.getNoteID());
Document doc = entry.getDocument();
if(null != doc){
if (doc.hasItem("TypeOfVehicle ")){
System.out.println("category has not " + "TypeOfVehicle ");
}
else{
System.out.println("category IS " + doc.getItemValueString("TypeOfVehicle "));
}
} else{
System.out.println("doc is null");
}
JsonJavaObject row = new JsonJavaObject();
JsonJavaObject jo = new JsonJavaObject();
String TypeOfVehicle = String.valueOf(columnValues.get(0));
if (null != TypeOfVehicle ) {
if (!TypeOfVehicle .equals("")){
jo.put("TypeOfVehicle ", TypeOfVehicle );
} else{
jo.put("TypeOfVehicle ", "Not categorized");
}
} else {
jo.put("TypeOfVehicle ", "Not categorized");
}
row.put("request", jo);
arr.put(count, row);
count++;
tmpentry = nav.getNextSibling(entry);
entry.recycle();
entry = tmpentry;
} else{
//tmpentry = nav.getNextCategory();
//entry.recycle();
//entry = tmpentry;
}
}
json.put("data", arr);
vw.setAutoUpdate(true);
vw.recycle();
}
}
} catch (Exception e) {
OpenLogUtil.logErrorEx(e, JSFUtil.getXSPContext().getUrl().toString(), Level.SEVERE, null);
}
return json;
}

What you're doing wrong is trying to treat any single view entry as both a category and a document. A single view entry can only be one of a category, a document, or a total.
If you have an entry for which isCategory() returns true, then for the same entry:
isDocument() will return false.
getDocument() will return null.
getNoteID() will return an empty string.
If the only thing you need is top-level categories, then get the first entry from the navigator and iterate over entries using nav.getNextSibling(entry) as you're already doing, but:
Don't try to get documents, note ids, or fields.
Use entry.getColumnValues().get(0) to get the value of the first column for each category.
If the view contains any uncategorised documents, it's possible that entry.getColumnValues().get(0) might throw an exception, so you should also check that entry.getColumnValues().size() is at least 1 before trying to get a value.
If you need any extra data beyond just top-level categories, then note that subcategories and documents are children of their parent categories.
If an entry has a subcategory, nav.getChild(entry) will get the first subcategory of that entry.
If an entry has no subcategories, but is a category which contains documents, nav.getChild(entry) will get the first document in that category.

Removing duplicate key-value pairs in a map with values being in a list

Below is my code to detect abbreviations and their long forms. The code loops over a line in a document, loops over each word of that line and identifies an acronym candidate. It then again loops over each line of the document to find an appropriate long form for the abbreviation. My issue is if an acronym occurs multiple times in a document my output contains multiple instances of it. I just want to print an acronym only once with all its possible long forms. Here's my code:
public static void main(String[] args) throws FileNotFoundException
{
BufferedReader in = new BufferedReader(new FileReader("D:\\Workspace\\resource\\SampleSentences.txt"));
String str=null;
ArrayList<String> lines = new ArrayList<String>();
String matchingLongForm;
List <String> matchingLongForms = new ArrayList<String>() ;
List <String> shortForm = new ArrayList<String>() ;
Map<String, List<String>> abbreviationPairs = new HashMap<String, List<String>>();
try
{
while((str = in.readLine()) != null){
lines.add(str);
}
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
String[] linesArray = lines.toArray(new String[lines.size()]);
// document wide search for abbreviation long form and identifying several appropriate matches
for (String line : linesArray){
for (String word : (Tokenizer.getTokenizer().tokenize(line))){
if (isValidShortForm(word)){
for (int i = 0; i < linesArray.length; i++){
matchingLongForm = extractBestLongForm(word, linesArray[i]);
//shortForm.add(word);
if (matchingLongForm != null && !(matchingLongForms.contains(matchingLongForm))){
matchingLongForms.add(matchingLongForm);
//System.out.println(matchingLongForm);
abbreviationPairs.put(word, matchingLongForms);
//matchingLongForms.clear();
}
}
if (abbreviationPairs != null){
//for(abbreviationPairs.)
System.out.println("Abbreviation Pair:" + "\t" + abbreviationPairs);
abbreviationPairs.clear();
matchingLongForms.clear();
//System.out.println("Abbreviation Pair:" + "\t" + abbreviationPairsNew);
}
else
continue;
}
}
}
}
Here's the current output:
Abbreviation Pair: {GLBA=[Gramm Leach Bliley act]}
Abbreviation Pair: {NCUA=[National credit union administration]}
Abbreviation Pair: {FFIEC=[Federal Financial Institutions Examination Council]}
Abbreviation Pair: {CFR=[comments for the Report]}
Abbreviation Pair: {CFR=[comments for the Report]}
Abbreviation Pair: {CFR=[comments for the Report]}
Abbreviation Pair: {CFR=[comments for the Report]}
Abbreviation Pair: {OFAC=[Office of Foreign Assets Control]}

Try to use java.util.Set to store your matching short forms and long forms. From the javadoc of the class:
... If this set already contains the element, the call leaves the set unchanged and returns false. In combination with the restriction on constructors, this ensures that sets never contain duplicate elements...

You want a key value pair for abbreviation and text. So you should use Map.
A map cannot contain duplicate keys; each key can map to at most one value.
The Problem is in the position of the output and not in the map.
You try to output in the loop, so the Map is shown multiple time.
Move the code outside the loop:
if (abbreviationPairs != null){
//for(abbreviationPairs.)
System.out.println("Abbreviation Pair:" + "\t" + abbreviationPairs);
abbreviationPairs.clear();
matchingLongForms.clear();
//System.out.println("Abbreviation Pair:" + "\t" + abbreviationPairsNew);
}

Here's the solution
Thanks to code_angel and Holger
Move the printing code outside the loop and create a new list for every matchingLongForm.
for (String line : linesArray){
for (String word : (Tokenizer.getTokenizer().tokenize(line))){
if (isValidShortForm(word)){
for (int i = 0; i < linesArray.length; i++){
matchingLongForm = extractBestLongForm(word, linesArray[i]);
List <String> matchingLongForms = new ArrayList<String>() ;
if (matchingLongForm != null && !(matchingLongForms.contains(matchingLongForm))&& !(abbreviationPairs.containsKey(word))){
matchingLongForms.add(matchingLongForm);
//System.out.println(matchingLongForm);
abbreviationPairs.put(word, matchingLongForms);
//matchingLongForms.clear();
}
}
}
}
}
if (abbreviationPairs != null){
System.out.println("Abbreviation Pair:" + "\t" + abbreviationPairs);
//abbreviationPairs.clear();
//matchingLongForms.clear();
}
}
The new output:
Abbreviation Pair: {NCUA=[National credit union administration], FFIEC=[Federal Financial Institutions Examination Council], OFAC=[Office of Foreign Assets Control], MSSP=[Managed Security Service Providers], IS=[Information Systems], SLA=[Service level agreements], CFR=[comments for the Report], MIS=[Management Information Systems], IDS=[Intrusion detection systems], TSP=[Technology Service Providers], RFI=[risk that FIs], EIC=[Examples of in the cloud], TIER=[The institution should ensure], BCP=[Business continuity planning], GLBA=[Gramm Leach Bliley act], III=[It is important], FI=[Financial Institutions], RFP=[Request for proposal]}

manipulate and sort text file

I am working on a project where I have been given a text file and I have to add up the points for each team and printout the top 5 teams.
The text file looks like this:
FRAMae Berenice MEITE 455.455<br>
CHNKexin ZHANG 454.584<br>
UKRNatalia POPOVA 453.443<br>
GERNathalie WEINZIERL 452.162<br>
RUSEvgeny PLYUSHCHENKO 191.399<br>
CANPatrick CHAN 189.718<br>
CHNHan YAN 185.527<br>
CHNCheng & Hao 271.018<br>
ITAStefania & Ondrej 270.317<br>
USAMarissa & Simon 264.256<br>
GERMaylin & Daniel 260.825<br>
FRAFlorent AMODIO 179.936<br>
GERPeter LIEBERS 179.615<br>
JPNYuzuru HANYU 197.9810<br>
USAJeremy ABBOTT 165.654<br>
UKRYakov GODOROZHA 160.513<br>
GBRMatthew PARR 157.402<br>
ITAPaul Bonifacio PARKINSON 153.941<br>
RUSTatiana & Maxim 283.7910<br>
CANMeagan & Eric 273.109<br>
FRAVanessa & Morgan 257.454<br>
JPNNarumi & Ryuichi 246.563<br>
JPNCathy & Chris 352.003<br>
UKRSiobhan & Dmitri 349.192<br>
CHNXintong &Xun 347.881<br>
RUSYulia LIPNITSKAYA 472.9010<br>
ITACarolina KOSTNER 470.849<br>
JPNMao ASADA 464.078<br>
UKRJulia & Yuri 246.342<br>
GBRStacey & David 244.701<br>
USAMeryl &Charlie 375.9810<br>
CANTessa & Scott 372.989<br>
RUSEkaterina & Dmitri 370.278<br>
FRANathalie & Fabian 369.157<br>
ITAAnna & Luca 364.926<br>
GERNelli & Alexander 358.045<br>
GBRPenny & Nicholas 352.934<br>
USAAshley WAGNER 463.107<br>
CANKaetlyn OSMOND 462.546<br>
GBRJenna MCCORKELL 450.091<br>
The first three letters represent the team.
the rest of the text is the the competitors name.
The last digit is the score the competitor recived.
Code so far:
import java.util.Arrays;
public class project2 {
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] array = new String[41];
String[] info = new String[41];
String[] stats = new String[41];
String[] team = new String[41];
//.txt file location
FileInput fileIn = new FileInput();
fileIn.openFile("C:\\Users\\O\\Desktop\\turn in\\team.txt");
// txt file to array
int i = 0;
String line = fileIn.readLine();
array[i] = line;
i++;
while (line != null) {
line = fileIn.readLine();
array[i] = line;
i++;
}
//Splitting up Info/team/score into seprate arrays
for (int j = 0; j < 40; j++) {
team[j] = array[j].substring(0, 3).trim();
info[j] = array[j].substring(3, 30).trim();
stats[j] = array[j].substring(36).trim();
}
// Random stuff i have been trying
System.out.println(team[1]);
System.out.println(info[1]);
System.out.println(stats[1]);
MyObject ob = new MyObject();
ob.setText(info[0]);
ob.setNumber(7, 23);
ob.setNumber(3, 456);
System.out.println("Text is " + ob.getText() + " and number 3 is " + ob.getNumber(7));
}
}
I'm pretty much stuck at this point because I am not sure how to add each teams score together.

This looks like homework... First of all you need to examine how you are parsing the strings in the file.
You're saying: the first 3 characters are the country, which looks correct, but then you set the info to the 4th through the 30th characters, which isn't correct. You need to dynamically figure out where that ends and the score begins. There is a space between the "info" and the "stats," knowing that you could use String's indexOf function. (http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#indexOf(int))

Have a look at Maps.
A map is a collection that allows you to get data associated with a key in a very short time.
You can create a Map where the key is a country name, with value being the total points.
example:
Map<String,Integer> totalScore = new HashMap<>();
if (totalScore.containsKey("COUNTRYNAME"))
totalScore.put("COUNTRYNAME", totalScore.get("COUNTRYNAME") + playerScore)
else
totalScore.put("COUNTRYNAME",0)
This will add to the country score if the score exists, otherwise it will create a new totalScore for a country initialized to 0.

Not tested, but should give you some ideas:
public static void main(String... args)
throws Exception {
class Structure implements Comparable<Structure> {
private String team;
private String name;
private Double score;
public Structure(String team, String name, Double score) {
this.team = team;
this.name = name;
this.score = score;
}
public String getTeam() {
return team;
}
public String getName() {
return name;
}
public Double getScore() {
return score;
}
#Override
public int compareTo(Structure o) {
return this.score.compareTo(o.score);
}
}
File file = new File("path to your file");
List<String> lines = Files.readAllLines(Paths.get(file.toURI()), StandardCharsets.UTF_8);
Pattern p = Pattern.compile("(\\d+(?:\\.\\d+))");
List<Structure> structures = new ArrayList<Structure>();
for (String line : lines) {
Matcher m = p.matcher(line);
while (m.find()) {
String number = m.group(1);
String text = line.substring(0, line.indexOf(number) - 1);
double d = Double.parseDouble(number);
String team = text.substring(0, 3);
String name = text.substring(3, text.length());
structures.add(new Structure(team, name, d));
}
}
Collections.sort(structures);
List<Structure> topFive = structures.subList(0, 5);
for (Structure structure : topFive) {
System.out.println("Team: " + structure.getTeam());
System.out.println("Name: " + structure.getName());
System.out.println("Score: " + structure.getScore());
}
}
Just remove <br> from your file.

Loading file into memory
Your string splitting logic looks fine.
Create a class like PlayerData. Create one instance of that class for each row and set all the three fields into that using setters.
Keep adding the PlayerData objects into an array list.
Accumulating
Loop through the arraylist and accumulate the team scores into a hashmap. Create a Map to accumulate the team scores by mapping teamCode to totalScore.
Always store row data in a custom object for each row. String[] for each column is not a good way of holding data in general.

Take a look in File Utils. After that you can extract the content from last space character using String Utils e removing the <br> using it as a key for a TreeMap. Than you can have your itens ordered.
List<String> lines = FileUtils.readLines(yourFile);
Map<String, String> ordered = new TreeMap<>();
for (String s : lines) {
String[] split = s.split(" ");
String name = split[0].trim();
String rate = splt[1].trim().substring(0, key.length - 4);
ordered.put(rate, name);
}
Collection<String> rates = ordered.values(); //names ordered by rate
Of course that you need to adjust the snippet.

Is there a common Java method to trim every string in an object graph?

I'm hoping to trim all Strings that are part of an object graph.
So I have an object graph like so
RootElement
- name (String)
- adjective (String)
- items ArrayOfItems
- getItems (List<Item>)
- get(i) (Item)
Item
- name (String)
- value (double)
- alias (String)
- references ArrayOfReferences
- getReferences (List<Reference>)
- get(i) (Reference)
Reference
- prop1 (String)
- prop2 (Integer)
- prop3 (String)
There is a get and set pair for every property of every class represented in this object graph. Ideally every field of type String would end up trimmed, including enumerating any child objects contained in collections. There are no cycles contained within the object graph.
Is there any java library that implements some sort of generic object graph visitor pattern or String\Reflection utility library that does this?
An external third party library that does this would also be fine, it does not have to be part of the standard java libraries.

No, there's no built-in traversal for something like this, and remember that Java Strings are immutable, so you can't actually trim in place--you have to trim and replace. Some objects may not permit modification of their String variables.

Below is the explanation of solution that I have built using Java Reflection API. I have posted the working code (with its url to github) below. This solution mainly uses:
Java Reflection API
Independent handling of Java Collections
Recursion
To start with, I have used Introspector to go over the readMethods of the Class omitting the methods defined for Object
for (PropertyDescriptor propertyDescriptor : Introspector
.getBeanInfo(c, Object.class).getPropertyDescriptors()) {
Method method = propertyDescriptor.getReadMethod();
Cases
If the current level of Property is of type String
If its an Object Array of Properties
If its a String array
If its a type of Java Collection class
Separate placement for Map with special conditions to process its keys and values
This utility uses the Java Reflection API to traverse through an object graph with disciplined syntax of getters and setters and trims all strings encountered within an Object graph recursively.
Code
This entire util class with the main test class (and custom data types/pojos) is here on my github
Usage:
myObj = (MyObject) SpaceUtil.trimReflective(myObj);
Util method:
public static Object trimReflective(Object object) throws Exception {
if (object == null)
return null;
Class<? extends Object> c = object.getClass();
try {
// Introspector usage to pick the getters conveniently thereby
// excluding the Object getters
for (PropertyDescriptor propertyDescriptor : Introspector
.getBeanInfo(c, Object.class).getPropertyDescriptors()) {
Method method = propertyDescriptor.getReadMethod();
String name = method.getName();
// If the current level of Property is of type String
if (method.getReturnType().equals(String.class)) {
String property = (String) method.invoke(object);
if (property != null) {
Method setter = c.getMethod("set" + name.substring(3),
new Class<?>[] { String.class });
if (setter != null)
// Setter to trim and set the trimmed String value
setter.invoke(object, property.trim());
}
}
// If an Object Array of Properties - added additional check to
// avoid getBytes returning a byte[] and process
if (method.getReturnType().isArray()
&& !method.getReturnType().isPrimitive()
&& !method.getReturnType().equals(String[].class)
&& !method.getReturnType().equals(byte[].class)) {
System.out.println(method.getReturnType());
// Type check for primitive arrays (would fail typecasting
// in case of int[], char[] etc)
if (method.invoke(object) instanceof Object[]) {
Object[] objectArray = (Object[]) method.invoke(object);
if (objectArray != null) {
for (Object obj : (Object[]) objectArray) {
// Recursively revisit with the current property
trimReflective(obj);
}
}
}
}
// If a String array
if (method.getReturnType().equals(String[].class)) {
String[] propertyArray = (String[]) method.invoke(object);
if (propertyArray != null) {
Method setter = c.getMethod("set" + name.substring(3),
new Class<?>[] { String[].class });
if (setter != null) {
String[] modifiedArray = new String[propertyArray.length];
for (int i = 0; i < propertyArray.length; i++)
if (propertyArray[i] != null)
modifiedArray[i] = propertyArray[i].trim();
// Explicit wrapping
setter.invoke(object,
new Object[] { modifiedArray });
}
}
}
// Collections start
if (Collection.class.isAssignableFrom(method.getReturnType())) {
Collection collectionProperty = (Collection) method
.invoke(object);
if (collectionProperty != null) {
for (int index = 0; index < collectionProperty.size(); index++) {
if (collectionProperty.toArray()[index] instanceof String) {
String element = (String) collectionProperty
.toArray()[index];
if (element != null) {
// Check if List was created with
// Arrays.asList (non-resizable Array)
if (collectionProperty instanceof List) {
((List) collectionProperty).set(index,
element.trim());
} else {
collectionProperty.remove(element);
collectionProperty.add(element.trim());
}
}
} else {
// Recursively revisit with the current property
trimReflective(collectionProperty.toArray()[index]);
}
}
}
}
// Separate placement for Map with special conditions to process
// keys and values
if (method.getReturnType().equals(Map.class)) {
Map mapProperty = (Map) method.invoke(object);
if (mapProperty != null) {
// Keys
for (int index = 0; index < mapProperty.keySet().size(); index++) {
if (mapProperty.keySet().toArray()[index] instanceof String) {
String element = (String) mapProperty.keySet()
.toArray()[index];
if (element != null) {
mapProperty.put(element.trim(),
mapProperty.get(element));
mapProperty.remove(element);
}
} else {
// Recursively revisit with the current property
trimReflective(mapProperty.get(index));
}
}
// Values
for (Map.Entry entry : (Set<Map.Entry>) mapProperty
.entrySet()) {
if (entry.getValue() instanceof String) {
String element = (String) entry.getValue();
if (element != null) {
entry.setValue(element.trim());
}
} else {
// Recursively revisit with the current property
trimReflective(entry.getValue());
}
}
}
} else {// Catch a custom data type as property and send through
// recursion
Object property = (Object) method.invoke(object);
if (property != null) {
trimReflective(property);
}
}
}
} catch (Exception e) {
throw new Exception("Strings cannot be trimmed because: ", e);
}
return object;
}
Test
I also have a test class in there which creates a relatively complex object. The test class has different scenarios that cover:
String properties
Properties as custom datatypes which in turn have String properties
Properties as custom datatypes which in turn have properties as custom datatypes which in turn have String properties
List of custom data types
Set of Strings
Array of custom data types
Array of Strings
Map of String and custom data type
Object Graph:
Test Object Code Snippet:
public static Music buildObj() {
Song song1 = new Song();
Song song2 = new Song();
Song song3 = new Song();
Artist artist1 = new Artist();
Artist artist2 = new Artist();
song1.setGenre("ROCK ");
song1.setSonnet("X ");
song1.setNotes("Y ");
song1.setCompostions(Arrays.asList(new String[] { "SOME X DATA ",
"SOME OTHER DATA X ", "SOME MORE DATA X ", " " }));
Set<String> instruments = new HashSet<String>();
instruments.add(" GUITAR ");
instruments.add(" SITAR ");
instruments.add(" DRUMS ");
instruments.add(" BASS ");
song1.setInstruments(instruments);
song2.setGenre("METAL ");
song2.setSonnet("A ");
song2.setNotes("B ");
song2.setCompostions(Arrays.asList(new String[] { "SOME Y DATA ",
" SOME OTHER DATA Y ",
" SOME MORE DATA Y ", " " }));
song3.setGenre("POP ");
song3.setSonnet("DONT ");
song3.setNotes("KNOW ");
song3.setCompostions(Arrays.asList(new String[] { "SOME Z DATA ",
" SOME OTHER DATA Z ",
" SOME MORE DATA Z ", " " }));
artist1.setSongList(Arrays.asList(new Song[] { song1, song3 }));
artist2.setSongList(Arrays.asList(new Song[] { song1, song2, song3 }));
Map<String, Person> artistMap = new HashMap<String, Person>();
Person tutor1 = new Person();
tutor1.setName("JOHN JACKSON DOE ");
artistMap.put(" Name ", tutor1);
Person coach1 = new Person();
coach1.setName("CARTER ");
artistMap.put("Coach ", coach1);
artist2.setTutor(artistMap);
music.setSongs(Arrays.asList(new Song[] { song1, song2, song3 }));
music.setArtists(Arrays.asList(new Artist[] { artist1, artist2 }));
music.setLanguages(new String[] { " ENGLISH ", "FRENCH ",
"HINDI " });
Person singer1 = new Person();
singer1.setName("DAVID ");
Person singer2 = new Person();
singer2.setName("JACOB ");
music.setSingers(new Person[] { singer1, singer2 });
Human man = new Human();
Person p = new Person();
p.setName(" JACK'S RAGING BULL ");
SomeGuy m = new SomeGuy();
m.setPerson(p);
man.setMan(m);
music.setHuman(man);
return music;
}
Outcome:
#######BEFORE#######
>>[>>DAVID ---<<, >>JACOB ---<<]---[ ENGLISH , FRENCH , HINDI ]---[>>ROCK ---X ---Y ---[SOME X DATA , SOME OTHER DATA X , SOME MORE DATA X , ]---[ SITAR , GUITAR , BASS , DRUMS ]<<, >>METAL ---A ---B ---[SOME Y DATA , SOME OTHER DATA Y , SOME MORE DATA Y , ]---<<, >>POP ---DONT ---KNOW ---[SOME Z DATA , SOME OTHER DATA Z , SOME MORE DATA Z , ]---<<]---[>>---[>>ROCK ---X ---Y ---[SOME X DATA , SOME OTHER DATA X , SOME MORE DATA X , ]---[ SITAR , GUITAR , BASS , DRUMS ]<<, >>POP ---DONT ---KNOW ---[SOME Z DATA , SOME OTHER DATA Z , SOME MORE DATA Z , ]---<<]<<, >>{Coach =>>CARTER ---<<, Name =>>JOHN JACKSON DOE ---<<}---[>>ROCK ---X ---Y ---[SOME X DATA , SOME OTHER DATA X , SOME MORE DATA X , ]---[ SITAR , GUITAR , BASS , DRUMS ]<<, >>METAL ---A ---B ---[SOME Y DATA , SOME OTHER DATA Y , SOME MORE DATA Y , ]---<<, >>POP ---DONT ---KNOW ---[SOME Z DATA , SOME OTHER DATA Z , SOME MORE DATA Z , ]---<<]<<]---=> JACK'S RAGING BULL <=<<
Number of spaces : 644
#######AFTER#######
>>[>>DAVID---<<, >>JACOB---<<]---[ENGLISH, FRENCH, HINDI]---[>>ROCK---X---Y---[SOME X DATA, SOME OTHER DATA X, SOME MORE DATA X, ]---[GUITAR, SITAR, DRUMS, BASS]<<, >>METAL---A---B---[SOME Y DATA, SOME OTHER DATA Y, SOME MORE DATA Y, ]---<<, >>POP---DONT---KNOW---[SOME Z DATA, SOME OTHER DATA Z, SOME MORE DATA Z, ]---<<]---[>>---[>>ROCK---X---Y---[SOME X DATA, SOME OTHER DATA X, SOME MORE DATA X, ]---[GUITAR, SITAR, DRUMS, BASS]<<, >>POP---DONT---KNOW---[SOME Z DATA, SOME OTHER DATA Z, SOME MORE DATA Z, ]---<<]<<, >>{Name=>>JOHN JACKSON DOE---<<, Coach=>>CARTER---<<}---[>>ROCK---X---Y---[SOME X DATA, SOME OTHER DATA X, SOME MORE DATA X, ]---[GUITAR, SITAR, DRUMS, BASS]<<, >>METAL---A---B---[SOME Y DATA, SOME OTHER DATA Y, SOME MORE DATA Y, ]---<<, >>POP---DONT---KNOW---[SOME Z DATA, SOME OTHER DATA Z, SOME MORE DATA Z, ]---<<]<<]---=>JACK'S RAGING BULL<=<<
Number of spaces : 111
There is a non-zero count of the number of spaces in the above trimmed output because I didn't make an effort to override toString of any collections (List, Set) or Map. There are certain improvements to the code I want to make but for your case the solution should work just fine.
Limitations (further improvements)
Cannot handle undisciplined syntax of properties (invalid getters/setters)
Cannot handle chained Collections: for example, List<List<Person>> - because of the exclusive support to disciplined getters/setters convention
No Guava collection library support

Building off #SwissArmyKnife I converted his simple String trimming function into an interface with a default method. So any object where you would like to use object.trim(), you just have to add "implements Trimmable".
Simple String trim interface: Trimmable.class
/**
* Utility interface that trims all String fields of the implementing class.
*/
public interface Trimmable {
/**
* Trim all Strings
*/
default void trim(){
for (Field field : this.getClass().getDeclaredFields()) {
try {
field.setAccessible(true);
Object value = field.get(this);
if (value != null){
if (value instanceof String){
String trimmed = (String) value;
field.set(this, trimmed.trim());
}
}
} catch(Exception e) {
e.printStackTrace();
}
}
}
}
An object that we would like to be trimmable: Person.class (implements Trimmable interface)
public class Person implements Trimmable {
private String firstName;
private String lastName;
private int age;
// getters/setters omitted
}
Now you can use person.trim()
Person person = new Person();
person.setFirstName(" John ");
person.setLastName(" Doe");
person.setAge(30);
person.trim();

I made a simple method for trimming String values with Reflection API.
public Object trimStringValues(Object model){
for(Field field : model.getClass().getDeclaredFields()){
try{
field.setAccessible(true);
Object value = field.get(model);
String fieldName = field.getName();
if(value != null){
if(value instanceof String){
String trimmed = (String) value;
field.set(model, trimmed.trim());
}
}
}catch(Exception e){
e.printStackTrace();
}
}
}
I haven't bumped in to any problems with this one yet. I know its an old thread, but it might help somone whos is looking for something simple.

How to group data specific field wise?

I am getting data from database for specific category.
Suppose I select or pass data to query that category is Laptop then it give me data of all attribute and it's value.
Like :
My Code to getting and display data on JSP page is :
<%
List<String> attribNameList = (List<String>)request.getAttribute("attribName");
List<String> attribValueList = (List<String>)request.getAttribute("attribValue");
List<String> attribDataList = (List<String>)request.getAttribute("attribData");
String aname,aval,adata;
for(int i = 0 ; i<attribValueList.size() ; i++)
{
aname = attribNameList.get(i);
aval = attribValueList.get(i);
adata = attribDataList.get(i);
%>
<a><%=i%><%= aname %></a>
<a><%= aval %></a>
<%
if(adata == null)
{
}
else
{
%>
<a><%= adata %></a>
<%
}
%>
<br>
<%
}
%>
Here aname display attribute name i.e. RAM, Processor, etc.
aval display value i.e. 4, 2.8, etc.
and adata display last data i.e. GB, GHz, MP, etc.
Now I want to display data as category wise like all memory attribute will display first.
Like :
RAM 4 GB
HDD 1 TB
Cache 3 MB, etc.
How can I display data in such format ?
I have tried using if condition where adata variable checked with
if(adata.equals("GB")||adata.equals("TB")||adata.equals("MB"))
{
//memory category data display
}
else
{
//Other data
}
but it isn't working.
Any Suggestion Please...

How about creating a custom object to store your entries:
class MyDataRow implements Comparable<MyDataRow> {
private String aname;
private String aval;
private String adata;
// getters, setters, constructors etc
#Override
public int compareTo(MyDataRow other) {
final int BEFORE = -1;
final int EQUAL = 0;
final int AFTER = 1;
if(other == null) return AFTER;
if(other.getAdata().equals(this.adata)) return EQUALS;
if(this.adata.equals("GB")||this.adata.equals("TB")||this.adata.equals("MB"))
{
if(other.getAdata().equals("GB") || xxxxxxx) return EQUAL;
return BEFORE;
}
if(next category in the list... etc etc)
}
}
Then the result of your database query populates a List. In MyDataRow, you override the 'compareTo' method with the ordering logic that you want. Before you enter the loop that prints out your list to the page, call Collections.sort(myDataRowList) :
List<MyDataRow> myDataRowList = new ArrayList<MyDataRow>();
for(int i = 0 ; i<attribValueList.size() ; i++)
{
aname = attribNameList.get(i);
aval = attribValueList.get(i);
adata = attribDataList.get(i);
myDataRowList.add(new MyDataRow(aname, aval, adata);
}
Collections.sort(myDataRowList); // now your myDataRowList is sorted in the order you want
for(MyDataRow myDataRow : myDataRowList) {
// print rows to screen
}