Related
Given a string with repeating pattern here:
String s = NameJJ,ABC/firstname,120, NameBB,ABC/secondname,100,NameCC,ABC/thirdname,150,NameJJ,ABC/firstname,200,NameBB,ABC/secondname,300,NameCC,ABC/thirdname,500
Essentially I want way where when NameJJ and firstname are beside each other like at top it stores value beside them which is arraylist1 = [120,200].
Essentially I want way where all field with NameBB and secondname are beside each other to store the value beside them which is arraylist2 = [100,300].
Essentially I want way where all field with NameJJ and thirdname are beside each other to store the value beside them which is arraylist3 = [150,500].
I was trying to do this to say if string contains NameJJ and contains firstname should filter out value beside it but I'm confused on how I would do that, this is the code :
if (s.contains(NameJJ) && s.contains(firstname))
Pattern reg = Pattern.compile(",");
ArrayList<String> SANR = reg.splitAsStream(s)
.filter(role -> role.contains(""))
.map(String::trim)
.collect(Collectors.toCollection(ArrayList::new));
Your String s holds the complete data so if (s.contains(NameJJ) && s.contains(firstname)) will always be true.
You have to split the blocks first, then look at the values.
Your data block contains 3 data each so that's the number you have to divide by in loop condition and multiply with in array access
String s = "NameJJ,ABC/firstname,120, NameBB,ABC/secondname,100,NameCC,ABC/thirdname,150,NameJJ,ABC/firstname,200,NameBB,ABC/secondname,300,NameCC,ABC/thirdname,500";
String[] split = s.split(",");
List<Integer> first = new ArrayList<>();
List<Integer> second = new ArrayList<>();
List<Integer> third = new ArrayList<>();
for (int i = 0; i < split.length / 3; i++) {
// first data block is Name..
// second block is firstname/secondname/thirdname
// third block hold the number you want
if (split[3 * i].trim().equals("NameJJ") && split[3 * i + 1].trim().equals("ABC/firstname")) {
first.add(Integer.parseInt(split[3 * i + 2].trim()));
} else if (split[3 * i].trim().equals("NameBB") && split[3 * i + 1].trim().equals("ABC/secondname")) {
second.add(Integer.parseInt(split[3 * i + 2].trim()));
} else if (split[3 * i].trim().equals("NameCC") && split[3 * i + 1].trim().equals("ABC/thirdname")) {
third.add(Integer.parseInt(split[3 * i + 2].trim()));
}
}
System.out.println(first);
System.out.println(second);
System.out.println(third);
Output is
[120, 200]
[100, 300]
[150, 500]
As I've answered in a previous question of yours, whenever you're having a certain pattern repeating itself, you should use a regex to extract the sub-bits of your pattern.
Streams are not designed to keep track of a "first" or "last" element. They're mainly stateless operations, with a few exceptions for distinct, sorted and similar. Stateless operations start their execution even before the previous one has finished its computation. This is why they have no recollection of a first or last result and also why we cannot use them for this kind of tasks.
What you could do is to employ 3 regex to match your pattern for nameJJ, nameBB and nameCC, and use capturing groups to identity and extract every desired sub-bit.
The following 3 regex can be used to match your patterns:
(\w+)JJ,(\w+)\/(\w+),(\d+)
(\w+)BB,(\w+)\/(\w+),(\d+)
(\w+)CC,(\w+)\/(\w+),(\d+)
Here is a snippet of the code implementation:
public class Main {
public static void main(String[] args) {
String s = "NameJJ,ABC/firstname,120, NameBB,ABC/secondname,100,NameCC,ABC/thirdname,150,NameJJ,ABC/firstname,200,NameBB,ABC/secondname,300,NameCC,ABC/thirdname,500";
List<Integer> listNameJJ = getList("(\\w+)JJ,(\\w+)\\/(\\w+),(\\d+)", s);
List<Integer> listNameBB = getList("(\\w+)BB,(\\w+)\\/(\\w+),(\\d+)", s);
List<Integer> listNameCC = getList("(\\w+)CC,(\\w+)\\/(\\w+),(\\d+)", s);
System.out.println(listNameJJ);
System.out.println(listNameBB);
System.out.println(listNameCC);
}
public static List<Integer> getList(String regex, String str) {
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(str);
List<Integer> list = new ArrayList<>();
while (matcher.find()) {
list.add(Integer.valueOf(matcher.group(4)));
}
return list;
}
}
Here is also a link to test the code above:
https://ideone.com/TES5UY
Here is another example,
public class Application {
public static void main(String[] args) {
String yourString = "NameJJ,ABC/firstname,120, NameBB,ABC/secondname,100,NameCC,ABC/thirdname,150,NameJJ,ABC/firstname,200,NameBB,ABC/secondname,300,NameCC,ABC/thirdname,500";
String myString = "NameKK,ZXY/kname,510, NameQQ,HLM/kname,210, NameKK,ZXY/kname,210,";
// Test 1
System.out.println(getValues("NameJJ", "firstname", yourString));
// Test 2
System.out.println(getValues("NameKK", "kname", myString));
}
private static List<Integer> getValues(String str1, String str2, String inputString) {
// Note* List is an ordered sequence of elements.
List<Integer> value = new ArrayList<Integer>();
// Extract Values
Matcher m = Pattern.compile("-?\\d+(,\\d+)*?\\.?\\d+?")
.matcher(inputString);
while (m.find()) {
value.add(Integer.parseInt(m.group().trim()));
}
// Extract Keys
List<String> key = List.of(inputString.split("\\d+"));
List<Integer> result = new ArrayList<Integer>();
// Filtering
for (int i = 0; i < value.size(); i++) {
if (key.get(i).trim().contains(str1)
&& key.get(i).trim().contains(str2)) {
result.add(value.get(i));
}
}
return result;
}
}
Console O/P:
[120, 200]
[510, 210]
How can I convert a String into a HashMap?
String value = "{first_name = naresh, last_name = kumar, gender = male}"
into
Map<Object, Object> = {
first_name = naresh,
last_name = kumar,
gender = male
}
Where the keys are first_name, last_name and gender and the values are naresh, kumar, male.
Note: Keys can be any thing like city = hyderabad.
I am looking for a generic approach.
This is one solution. If you want to make it more generic, you can use the StringUtils library.
String value = "{first_name = naresh,last_name = kumar,gender = male}";
value = value.substring(1, value.length()-1); //remove curly brackets
String[] keyValuePairs = value.split(","); //split the string to creat key-value pairs
Map<String,String> map = new HashMap<>();
for(String pair : keyValuePairs) //iterate over the pairs
{
String[] entry = pair.split("="); //split the pairs to get key and value
map.put(entry[0].trim(), entry[1].trim()); //add them to the hashmap and trim whitespaces
}
For example you can switch
value = value.substring(1, value.length()-1);
to
value = StringUtils.substringBetween(value, "{", "}");
if you are using StringUtils which is contained in apache.commons.lang package.
You can do it in single line, for any object type not just Map.
(Since I use Gson quite liberally, I am sharing a Gson based approach)
Gson gson = new Gson();
Map<Object,Object> attributes = gson.fromJson(gson.toJson(value),Map.class);
What it does is:
gson.toJson(value) will serialize your object into its equivalent Json representation.
gson.fromJson will convert the Json string to specified object. (in this example - Map)
There are 2 advantages with this approach:
The flexibility to pass an Object instead of String to toJson method.
You can use this single line to convert to any object even your own declared objects.
String value = "{first_name = naresh,last_name = kumar,gender = male}"
Let's start
Remove { and } from the String>>first_name = naresh,last_name = kumar,gender = male
Split the String from ,>> array of 3 element
Now you have an array with 3 element
Iterate the array and split each element by =
Create a Map<String,String> put each part separated by =. first part as Key and second part as Value
#Test
public void testToStringToMap() {
Map<String,String> expected = new HashMap<>();
expected.put("first_name", "naresh");
expected.put("last_name", "kumar");
expected.put("gender", "male");
String mapString = expected.toString();
Map<String, String> actual = Arrays.stream(mapString.replace("{", "").replace("}", "").split(","))
.map(arrayData-> arrayData.split("="))
.collect(Collectors.toMap(d-> ((String)d[0]).trim(), d-> (String)d[1]));
expected.entrySet().stream().forEach(e->assertTrue(actual.get(e.getKey()).equals(e.getValue())));
}
try this out :)
public static HashMap HashMapFrom(String s){
HashMap base = new HashMap(); //result
int dismiss = 0; //dismiss tracker
StringBuilder tmpVal = new StringBuilder(); //each val holder
StringBuilder tmpKey = new StringBuilder(); //each key holder
for (String next:s.split("")){ //each of vale
if(dismiss==0){ //if not writing value
if (next.equals("=")) //start writing value
dismiss=1; //update tracker
else
tmpKey.append(next); //writing key
} else {
if (next.equals("{")) //if it's value so need to dismiss
dismiss++;
else if (next.equals("}")) //value closed so need to focus
dismiss--;
else if (next.equals(",") //declaration ends
&& dismiss==1) {
//by the way you have to create something to correct the type
Object ObjVal = object.valueOf(tmpVal.toString()); //correct the type of object
base.put(tmpKey.toString(),ObjVal);//declaring
tmpKey = new StringBuilder();
tmpVal = new StringBuilder();
dismiss--;
continue; //next :)
}
tmpVal.append(next); //writing value
}
}
Object objVal = object.valueOf(tmpVal.toString()); //same as here
base.put(tmpKey.toString(), objVal); //leftovers
return base;
}
examples
input : "a=0,b={a=1},c={ew={qw=2}},0=a"
output : {0=a,a=0,b={a=1},c={ew={qw=2}}}
Should Use this way to convert into map :
String student[] = students.split("\\{|}");
String id_name[] = student[1].split(",");
Map<String,String> studentIdName = new HashMap<>();
for (String std: id_name) {
String str[] = std.split("=");
studentIdName.put(str[0],str[1]);
}
You can use below library to convert any string to Map object.
<!-- https://mvnrepository.com/artifact/io.github.githubshah/gsonExtension -->
<dependency>
<groupId>io.github.githubshah</groupId>
<artifactId>gsonExtension</artifactId>
<version>4.1.0</version>
</dependency>
Using Java Stream:
Map<String, String> map = Arrays.stream(value.replaceAll("[{}]", " ").split(","))
.map(s -> s.split("=", 2))
.collect(Collectors.toMap(s -> s[0].trim(), s -> s[1].trim()));
Arrays.stream() to convert string array to stream.
replaceAll("[{}]", " "): regex version to replace both braces.
split(","): Split the string by , to get individual map entries.
s.split("=", 2): Split them by = to get the key and the value and ensure that the array is never larger than two elements.
The collect() method in Stream API collects all objects from a stream object and stored in the type of collection.
Collectors.toMap(s -> s[0].trim(), s -> s[1].trim()): Accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.
I have a String[] with values like so:
line_str = "1,3,4,3,11,2,2,6,7"
I want to find unique value and keep the arrangement of value
unique_str="1,3,4,11,2,6,7"
I'm using a HashSet but the output is:
[1,6,7,4,11,3,2]
Here is my code:
String line_str = "1,3,4,3,11,2,2,6,7";
String[] str_arr = line_str.split(",");
Set<String> uniqueValue = new HashSet<>(Arrays.asList(str_arr));
Toast.makeText(this, uniqueValue.toString(),Toast.LENGTH_LONG).show();
A HashSet will ensure no duplications and a LinkedHashSet will ensure each element remains in its designated position;
String line_str = "1,3,4,3,11,2,2,6,7";
String[] str_arr = line_str.split(",");
Set<Integer> uniqueNumbers = new LinkedHashSet<Integer>();
for(String num : str_arr) {
uniqueNumbers.add(Integer.parseInt(num));
}
If your input has any variance then you will need to handle that.
Using streams :
String line_str = "1,3,4,3,11,2,2,6,7";
String unique_str = Pattern.compile(",")
.splitAsStream(line_str)
.distinct()
.collect(Collectors.joining(","));
System.out.println(unique_str);
I have a string array that contains some information.
Example:
String [] testStringArray;
testStringArray[0]= Jim,35
Alex,45
Mark,21
testStringArray[1]= Ana,18
Megan,44
This is exactly how the information is. Now my problem is I want to make each element a seperate element in an array and I want to split it based on the \n character.
So I want
newArray[0]=Jim,35
newArray[1]=Alex,45
newArray[2]=Mark,21
newArray[3]=Ana,18
etc etc. I am aware of the split method but won't this just split each array element into a completely new array instead of combining them?
If anyone could help, it would be appreciated. Thanks
Something like this:
// Splits the given array of Strings on the given regex and returns
// the result in a single array.
public static String[] splitContent(String regex, String... input) {
List<String> list = new ArrayList<>();
for (String str : input) {
for (String split : str.split(regex)) {
list.add(split);
}
}
return list.toArray(new String[list.size()]);
}
you can call it this way:
String[] testStringArray = ...;
String[] newArray = splitContent("\n", testStringArray);
Because of the use of varargs you can also call it like this:
String[] newArray = splitContent("\n", str1, str2, str3, str4);
where strX are String variables. You can use any amount you want. So either pass an array of Strings, or any amount of Strings you like.
If you don't need the old array anymore, you can also use it like this:
String[] yourArray = ...;
yourArray = splitContent("\n", yourArray);
String[] testStringArray = new String[2];
ArrayList<String> result = new ArrayList<String>();
testStringArray[0]= "Jim,35\nAlex,45\nMark,21";
testStringArray[1]= "Jiam,35\nAleax,45\nMarak,21";
for(String s : testStringArray) {
String[] temp = s.split("\n");
for(String t : temp) {
result.add(t);
}
}
String[] res = result.toArray(new String[result.size()]);
Try This is working Code >>
String[] testStringArray = new String[2]; // size of array
ArrayList<String> result = new ArrayList<String>();
testStringArray[0]= "Jim,35\nAlex,45\nMark,21"; // store value
testStringArray[1]= "Ana,18\nMegan,44";
for(String s : testStringArray) {
String[] temp = s.split("\n"); // split from \n
for(String t : temp) {
result.add(t); // add value in result
System.out.print(t);
}
}
result.toArray(new String[result.size()]);
you can first merge the strings into one string and then use the split method for the merged string.
testStringArray[0]= Jim,35
Alex,45
Mark,21
testStringArray[1]= Ana,18
Megan,44
StringBuffer sb = new StringBuffer();
for(String s : testStringArray){
s = s.trim();
sb.append(s);
if (!s.endWith("\n")){
sb.append("\n");
}
}
String[] array = sb.toString().split("\n");
Try this. It is simple and readable.
ArrayList<String> newArray = new ArrayList<String>();
for (String s : testStringArray) {
newArray.addAll(Arrays.asList(s.split("\\n"));
}
Firstly, you can't write what you just did. You made a String array, which can only contain Strings. Furthermore the String has to be in markers "" like "some text here".
Furthermore, there can only be ONE String at one place in the array like:
newArray[0] = "Jim";
newArray[1] = "Alex";
And NOT like:
newArray[0] = Jim;
And CERTAINLY NOT like:
// Here you're trying to put 2 things in 1 place in the array-index
newArray[0] = Jim, 35;
If you wan't to combine 2 things, like an name and age you have to use 2D array - or probably better in your case ArrayList.
Make a new class with following object:
public class Person {
String name;
int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
}
And afterwards go to your class where you want to use the original array, and write:
ArrayList<Person> someNameOfTheArrayList = new ArrayList<Person>();
someNameOfTheArrayList.add(new Person("Jim", 32));
someNameOfTheArrayList.add(new Person("Alex", 22));
Consider the following String :
5|12345|value1|value2|value3|value4+5|777|value1|value2|value3|value4?5|777|value1|value2|value3|value4+
Here is how I want to split string, split it with + so I get this result :
myArray[0] = "5|12345|value1|value2|value3|value4";
myArray[1] = "5|777|value1|value2|value3|value4?5|777|value1|value2|value3|value4";
if string has doesn't contain char "?" split it with "|" and continue to part II, if string does contain "?" split it and for each part split it with "|" and continue to part II.
Here is part II :
myObject.setAttribute1(newString[0]);
...
myObject.setAttribute4(newString[3]);
Here what I've got so far :
private static String input = "5|12345|value1|value2|value3|value4+5|777|value1|value2|value3|value4?5|777|value1|value2|value3|value4+";
public void mapObject(String input){
String[] myArray = null;
if (input.contains("+")) {
myArray = input.split("+");
} else {
myArray = new String[1];
myArray[0] = input;
}
for (int i = 0; i < myArray.length; i++) {
String[] secondaryArray = null;
String[] myObjectAttribute = null;
if (myArray[i].contains("?")) {
secondaryArray = temporaryString.myArray[i].split("?");
for (String string : secondaryArray) {
myObjectAttribute = string.split("\\|");
}
} else {
myObjectAttribute = myArray[i].toString().split("\\|");
}
myObject.setAttribute1(myObjectAttribute[0]);
...
myObject.setAttribute4(myObjectAttribute[3]);
System.out.println(myObject.toString());
}
Problem :
When I split myArray, going trough for with myArray[0], everything set up nice as it should.
Then comes the myArray[1], its split into two parts then the second part overrides the value of the first(how do I know that?). I've overridden toString() method of myObject, when I finish I print the set values so I know that it overrides it, does anybody know how can I fix this?
I'm not quite sure what the intention is here, but in this snippet of code
secondaryArray = temporaryString.split("?");
for (String string : secondaryArray) {
myObjectAttribute = string.split("\\|");
}
if secondaryArray has two elements after the split operation, you are iterating over each half and re-assigning myObjectAttribute to the output of string.split("\|") each time. It doesn't matter what is in the first element of secondaryArray, as after this code runs myObjectAttribute is going to contain the result of split("\\|") on the last element in the array.
Also, there is no point in calling .toString() on a String object as you do in temporaryString = myArray[i].toString().
The code doesn't seem to be able to handle the possible expansion of strings in the secondary case. To make the code clearer, I would use a List rather than array.
private static String input = "5|12345|value1|value2|value3|value4+5|777|value1|value2|value3|value4?5|777|value1|value2|value3|value4+";
private void split(List<String> input, List<String> output, String split) {
for (String s: input) {
if (s.contains(split))
{
output.addAll(Arrays.asList(s.split(Pattern.quote(split)));
}
else
output.add(s);
}
}
public void mapObject(String input) {
List<String> inputSrings = new ArrayList<String>();
List<String> splitPlus = new ArrayList<String>();
inputStrings.add(input);
split(inputStrings, splitPlus);
List<String> splitQuest = new ArrayList<String>();
split(splitPlus, splitQuest, "?");
for (String s: splitQuest) {
// you can now set the attributes from the values in the list
// splitPipe
String[] attributes = s.split("\\|");
myObject.setAttribute1(attributes[0]);
....
myObject.setAttribute4(attributes[3]);
System.out.println(myObject);
}
}