Develop Reference

How to add values to the same string after splitting

I am getting value from a Bluetooth device, values separated by : colon. I want to get the first value and add it to the same string:
public String process(String raw) {
if (raw != null) {
String[] str_array = raw.split(":");
String humid1 = str_array[0];
if (humid1 != null) {
return raw.add(humid1);
}
} else {
Log.w(TAG, "provided string was null");
}
}

There is no add() method in String class. One can perform String concatenation in Java using + operator.
String s = "abc:def:ghi";
s = s + s.split(":")[0]; // or s += s.split(":")[0]
System.out.println(s);
The above snippet will print abc:def:ghiabc
Add null checks and index bounds checks as per your requirements.
Please check alternative ways at String Concatenation | StackOverflow
EDIT (As per OP's comment on question)
If you're looking to make changes to the input String object 'raw' and expect it to reflect in caller method, then it's not possible as String is immutable in Java. Correct way to achieve that would be to return the result from your method and assign that to String in caller method.
public void myMethod() {
String s = "abc:def:ghi";
s = process(s);
System.out.println(s);
}
public String process(String raw) {
if (raw != null) {
String[] str_array = raw.split(":");
String humid1 = str_array[0];
if (humid1 != null) {
return humid1;
}
}
return null; \\ or throw exception as per your choice.
}
The above snippet should print abc. More details String Immutability in Java | StackOverflow.

Multiple string replacements without affecting substituted text in subsequent iterations

I've posted about letters earlier, but this is an another topic, I have a json response that contain 2 objects, from and to , from is what to change, and to is what it will be changed to .
My code is :
// for example, the EnteredText is "ab b test a b" .
EnteredString = EnteredText.getText().toString();
for (int i = 0; i < m_jArry.length(); i++) {
JSONObject jo_inside = m_jArry.getJSONObject(i);
String Original = jo_inside.getString("from");
String To = jo_inside.getString("to");
if(isMethodConvertingIn){
EnteredString = EnteredString.replace(" ","_");
EnteredString = EnteredString.replace(Original,To + " ");
} else {
EnteredString = EnteredString.replace("_"," ");
EnteredString = EnteredString.replace(To + " ", Original);
}
}
LoadingProgress.setVisibility(View.GONE);
SetResultText(EnteredString);
ShowResultCardView();
For example, the json response is :
{
"Response":[
{"from":"a","to":"bhduh"},{"from":"b","to":"eieja"},{"from":"tes","to":"neesj"}
]
}
String.replace() method won't work here, because first it will replace a to bhduh, then b to eieja, BUT here's the problem, it will convert b in bhduh to eieja, which i don't want to.
I want to perfectly convert the letters and "words" in the String according the Json, but that what i'm failing at .
New Code :
if(m_jArry.length() > 0){
HashMap<String, String> m_li;
EnteredString = EnteredText.getText().toString();
Log.i("TestAf_","Before Converting: " + EnteredString);
HashMap<String,String> replacements = new HashMap<String,String>();
for (int i = 0; i < m_jArry.length(); i++) {
JSONObject jo_inside = m_jArry.getJSONObject(i);
String Original = jo_inside.getString("from");
String To = jo_inside.getString("to");
if(isMethodConvertingIn){
//EnteredString = EnteredString.replace(" ","_");
replacements.put(Original,To);
Log.i("TestAf_","From: " + Original + " - To: " + To + " - Loop: " + i);
//EnteredString = EnteredString.replace(" ","_");
//EnteredString = EnteredString.replace(Original,To + " ");
} else {
EnteredString = EnteredString.replace("_"," ");
EnteredString = EnteredString.replace("'" + To + "'", Original);
}
}
Log.i("TestAf_","After Converting: " + replaceTokens(EnteredString,replacements));
// Replace Logic Here
// When Finish, Do :
LoadingProgress.setVisibility(View.GONE);
SetResultText(replaceTokens(EnteredString,replacements));
ShowResultCardView();
Output :
10-10 19:51:19.757 12113-12113/? I/TestAf_: Before Converting: ab a ba
10-10 19:51:19.757 12113-12113/? I/TestAf_: From: a - To: bhduh - Loop: 0
10-10 19:51:19.757 12113-12113/? I/TestAf_: From: b - To: eieja - Loop: 1
10-10 19:51:19.757 12113-12113/? I/TestAf_: From: o - To: neesj - Loop: 2
10-10 19:51:19.758 12113-12113/? I/TestAf_: After Converting: ab a ba

You question would be clearer if you gave the expected output for the function.
Assuming it is: ab b test a b >>>> bhduheieja eieja neesjt bhduh eieja
then see the following, the key point in the Javadoc being "This will not repeat"
http://commons.apache.org/proper/commons-lang/javadocs/api-release/org/apache/commons/lang3/StringUtils.html#replaceEach(java.lang.String,%20java.lang.String[],%20java.lang.String[])
Replaces all occurrences of Strings within another String.
A null reference passed to this method is a no-op, or if any "search
string" or "string to replace" is null, that replace will be ignored.
This will not repeat. For repeating replaces, call the overloaded
method.
Example 1
import org.apache.commons.lang3.StringUtils;
public class StringReplacer {
public static void main(String[] args) {
String input = "ab b test a b";
String output = StringUtils.replaceEach(input, new String[] { "a", "b", "tes" },
new String[] { "bhduh", "eieja", "neesj" });
System.out.println(input + " >>>> " + output);
}
}
Example 2
import org.apache.commons.lang3.StringUtils;
public class StringReplacer {
public static void main(String[] args) {
String input = "this is a test string with foo";
String output = StringUtils.replaceEach(input, new String[] { "a", "foo" },
new String[] { "foo", "bar"});
System.out.println(input + " >>>> " + output);
}
}

Try following:
Solution 1:
Traverse the String characters one by one and move the new String to a new StringBuffer or StringBuilder, then call toString() to get the result. This will need you to implement string matching algorithm.
Solution 2 (Using Regex):
For this, you must know the domain of your string. For example, it is [a-zA-Z] then other arbitrary characters (not part of domain) can be used for intermediate step. First replace the actual characters with arbitrary one then arbitrary ones with the target. In example below, [!##] are the arbitrary characters. These can be any random \uxxxx value as well.
String input = "a-b-c";
String output = input.replaceAll("[a]", "!").replaceAll("[b]", "#").replaceAll("[c]", "#");
output = output.replaceAll("[!]", "bcd").replaceAll("[#]", "cde").replaceAll("[#]", "def");
System.out.println("input: " + input);
System.out.println("Expected: bcd-cde-def");
System.out.println("Actual: " + output);

Your issue is quite common. To sum things up :
String test = "this is a test string with foo";
System.out.println(test.replace("a", "foo").replace("foo", "bar"));
Gives : this is bar test string with bar
Expected by you : this is foo test string with bar
You can use StrSubstitutor from Apache Commons Lang
But first you will have to inject placeholders in your string :
String test = "this is a test string with foo";
Map<String, String> valuesMap = new HashMap<>();
valuesMap.put("a", "foo");
valuesMap.put("foo", "bar");
String testWithPlaceholder = test;
// Preparing the placeholders
for (String value : valuesMap.keySet())
{
testWithPlaceholder = testWithPlaceholder.replace(value, "${"+value+"}");
}
And then, use StrSubstitutor
System.out.println(StrSubstitutor.replace(testWithPlaceholder, valuesMap));
It gives : this is foo test string with bar

Here is an method which is strictly just Java. I tried not to use any Java 8 methods here.
public static String translate(final String str, List<String> from, List<String> to, int index) {
StringBuilder components = new StringBuilder();
String token, replace;
int p;
if (index < from.size()) {
token = from.get(index);
replace = to.get(index);
p = 0;
for (int i = str.indexOf(token, p); i != -1; i = str.indexOf(token, p)) {
if (i != p) {
components.append(translate(str.substring(p, i), from, to, index + 1));
}
components.append(replace);
p = i + token.length();
}
return components.append(translate(str.substring(p), from, to, index + 1)).toString();
}
return str;
}
public static String translate(final String str, List<String> from, List<String> to) {
if (null == str) {
return null;
}
return translate(str, from, to, 0);
}
Sample test program
public static void main(String []args) {
String EnteredString = "aa hjkyu batesh a";
List<String> from = new ArrayList<>(Arrays.asList("a", "b", "tes"));
List<String> to = new ArrayList<>(Arrays.asList("bhduh", "eieja", "neesj"));
System.out.println(translate(EnteredString, from, to));
}
Output:
bhduhbhduh hjkyu eiejabhduhneesjh bhduh
Explaination
The algorithm is recursive, and it simply does the following
If a pattern found in the string matches a pattern in the from list
if there is any string before that pattern, apply the algorithm to that string
replace the found pattern with the corresponding pattern in the to list
append the replacement to the new string
discard the pattern in the from list and repeat the algorithm for the rest of the string
Otherwise append the rest of the string to the new string

You could use split like:
String[] pieces = jsonResponse.split("},{");
then you just parse the from and to in each piece and apply them with replace() then put the string back together again. (and please get your capitalization of your variables/methods right - makes it very hard to read the way you have it)

Apache Commons StringUtils::replaceEach does this.
String[] froms = new String[] {"a", "b"};
String[] tos = new String[] {"b","c"};
String result = StringUtils.replaceEach("ab", froms, tos);
// result is "bc"

Why not keep it very simple (if the JSON is always in same format, EG: from the same system). Instead of replacing from with to, replace the entire markup:
replace "from":"*from*" with "from":"*to*"

Why not just change the actual "to" and "from" labels? That way, you don't run into a situation where "bhudh" becomes "eieja". Just do a string replace on "from" and "to".

How to replace special character In Android?

I have to create file with user define name. If User can use the special character then i want to replace that special character with my specific string. i found the method like this.
String replaceString(String string) {
return string.replaceAll("special_char","");
}
but how to use this method.?

relpaceAll method is required regular expression and replace string.
string.replaceAll("regularExpression","replaceString");
You can use this regular expression :
"[;\\/:*?\"<>|&']"
e.g.
String replaceString(String string) {
return string.replaceAll("[;\\/:*?\"<>|&']","replaceString");
}

Try
regular expression
static String replaceString(String string) {
return string.replaceAll("[^A-Za-z0-9 ]","");// removing all special character.
}
call
public static void main(String[] args) {
String str=replaceString("Hello\t\t\t.. how\t\t are\t you."); // call to replace special character.
System.out.println(str);
}
output:
Hello how are you

use below function to replace your string
public static String getString(String p_value)
{
String p_value1 = p_value;
if(p_value1 != null && ! p_value1.isEmpty())
{
p_value1 = p_value1.replace("Replace string from", "Replace String to");
return p_value1;
}
else
{
return "";
}
}
example
Replace string from = "\n";
Replace String to = "\r\n";
after using above function \n is replace with \r\n

**this method make two line your string data after specific word **
public static String makeTwoPart(String data, String cutAfterThisWord){
String result = "";
String val1 = data.substring(0, data.indexOf(cutAfterThisWord));
String va12 = data.substring(val1.length(), data.length());
String secondWord = va12.replace(cutAfterThisWord, "");
Log.d("VAL_2", secondWord);
String firstWord = data.replace(secondWord, "");
Log.d("VAL_1", firstWord);
result = firstWord + "\n" + secondWord;
return result;
}

Android - How to check the existence of a string value in another comma separated string

Android - How to check the existence of a string value in another comma separated string .
String all_vals = "617,618,456,1,234,5,5678,225";
String check_val= "456";
How to check like,
if (all_vals contains check_val) {
}

Convert the comma-separated string to an array with split, then convert it to a List with Arrays.asList, then use contains.
String all_vals = "617,618,456,1,234,5,5678,225";
List<String> list = Arrays.asList(all_vals.split(","));
if (list.contains(check_val)) {
}
This will prevent the false positives from just checking if the substring exists in the list with contains directly on the string all_vals, e.g. all_vals.contains("4") would return true in the direct String#contains case.

Java 8:
String all_vals = "617,618,456,1,234,5,5678,225";
String check_val= "5678";
Arrays.stream(all_vals.split(",")).anyMatch(check_val:: equals)
if(Arrays.stream(all_vals.split(",")).anyMatch(check_val:: equals)){
System.out.println("The value is present");
}

String all_vals = "617,618,456,1,234,5,5678,225";
String check_val= "5678";
int place = 1;
String[] strings = all_vals.split(",");
for (String str : strings) {
if(str.equals(check_val))
{
System.out.println("We have string in all_val on place: " + place);
}
place++;
}

String all_vals = "617,618,456,1,234,5,5678,225";
String check_val= "456";
if (all_vals.startsWith(check_val) ||
all_vals.endsWith(check_val) ||
all_vals.contains("," + check_val + ","))
{
System.out.println("value found in string");
}

Java equivalent of PHP's implode(',' , array_filter( array () ))

I often use this piece of code in PHP
$ordine['address'] = implode(', ', array_filter(array($cliente['cap'], $cliente['citta'], $cliente['provincia'])));
It clears empty strings and join them with a ",". If only one remains it doesn't add an extra unneeded comma. It doesn't add a comma at the end. If none remains it returns empty string.
Thus I can get one of the following results
""
"Street abc 14"
"Street abc 14, 00168"
"Street abc 14, 00168, Rome"
What is the best Java implementation (less code) in Java without having to add external libraries (designing for Android)?

Updated version using Java 8 (original at the end of post)
If you don't need to filter any elements you can use
String.join(CharSequence delimiter, CharSequence... elements)
String.join(" > ", new String[]{"foo", "bar"});
String.join(" > ", "foo", "bar");
or String.join(CharSequence delimiter, Iterable<? extends CharSequence> elements)
String.join(" > ", Arrays.asList("foo", "bar"));
Since Java 8 we can use StringJoiner (instead of originally used StringBulder) and simplify our code.
Also to avoid recompiling " *" regex in each call of matches(" *") we can create separate Pattern which will hold its compiled version in some field and use it when needed.
private static final Pattern SPACES_OR_EMPTY = Pattern.compile(" *");
public static String implode(String separator, String... data) {
StringJoiner sb = new StringJoiner(separator);
for (String token : data) {
if (!SPACES_OR_EMPTY.matcher(token).matches()) {
sb.add(token);
}
}
return sb.toString();
}
With streams our code can look like.
private static final Predicate<String> IS_NOT_SPACES_ONLY =
Pattern.compile("^\\s*$").asPredicate().negate();
public static String implode(String delimiter, String... data) {
return Arrays.stream(data)
.filter(IS_NOT_SPACES_ONLY)
.collect(Collectors.joining(delimiter));
}
If we use streams we can filter elements which Predicate. In this case we want predicate to accept strings which are not only spaces - in other words string must contain non-whitespace character.
We can create such Predicate from Pattern. Predicate created this way will accept any strings which will contain substring which could be matched by regex (so if regex will look for "\\S" predicate will accept strings like "foo ", " foo bar ", "whatever", but will not accept " " nor " ").
So we can use
Pattern.compile("\\S").asPredicate();
or possibly little more descriptive, negation of strings which are only spaces, or empty
Pattern.compile("^\\s*$").asPredicate().negate();
Next when filter will remove all empty, or containing only spaces Strings we can collect rest of elements. Thanks to Collectors.joining we can decide which delimiter to use.
Original answer (before Java 8)
public static String implode(String separator, String... data) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < data.length - 1; i++) {
//data.length - 1 => to not add separator at the end
if (!data[i].matches(" *")) {//empty string are ""; " "; " "; and so on
sb.append(data[i]);
sb.append(separator);
}
}
sb.append(data[data.length - 1].trim());
return sb.toString();
}
You can use it like
System.out.println(implode(", ", "ab", " ", "abs"));
or
System.out.println(implode(", ", new String[] { "ab", " ", "abs" }));
Output ab, abs

Why so serious?
Try StringUtils.join(new String[] {"Hello", "World", "!"}, ", ") !

Here is an Android-specific answer that may be helpful to some:
String combined = TextUtils.join(",", new String[]{"Red", "Green", "Blue"});
// Result => Red,Green,Blue
Be sure to import the TextUtils class:
import android.text.TextUtils;

You'd have to add your strings to an ArrayList, remove empty ones, and format it accordingly:
public static String createAddressString( String street, String zip_code, String country) {
List<String> list = new ArrayList<String>();
list.add( street);
list.add( zip_code);
list.add( country);
// Remove all empty values
list.removeAll(Arrays.asList("", null));
// If this list is empty, it only contained blank values
if( list.isEmpty()) {
return "";
}
// Format the ArrayList as a string, similar to implode
StringBuilder builder = new StringBuilder();
builder.append( list.remove(0));
for( String s : list) {
builder.append( ", ");
builder.append( s);
}
return builder.toString();
}
Additionally, if you had String[], an array of strings, you can easily add them to an ArrayList:
String[] s;
List<String> list = new ArrayList<String>( Arrays.asList( s));

Using Streams (for Java 8 and later) would be an alternate possible solution for this.
You are required to import
java.util.stream.Collectors;
to use the join process
You may use:
Arrays.asList("foo","bar").stream().collect(Collectors.joining(","));
to achieve the desired result.

A simple Implode
public static String implode(String glue, String[] strArray)
{
String ret = "";
for(int i=0;i<strArray.length;i++)
{
ret += (i == strArray.length - 1) ? strArray[i] : strArray[i] + glue;
}
return ret;
}
You can create overloads for it..
The above it equivalent of php implode.
Here is what you want:
import java.lang.*
public static String customImplode(String glue, String[] strArray)
{
String ret = "";
for(int i=0;i<strArray.length;i++)
{
if (strArray[i].trim() != "")
ret += (i == strArray.length - 1) ? strArray[i] : strArray[i] + glue;
}
return ret;
}

Here's my implode implementation:
/**
* Implodes the specified items, gluing them using the specified glue replacing nulls with the specified
* null placeholder.
* #param glue The text to use between the specified items.
* #param nullPlaceholder The placeholder to use for items that are <code>null</code> value.
* #param items The items to implode.
* #return A <code>String</code> containing the items in their order, separated by the specified glue.
*/
public static final String implode(String glue, String nullPlaceholder, String ... items) {
StringBuilder sb = new StringBuilder();
for (String item : items) {
if (item != null) {
sb.append(item);
} else {
sb.append(nullPlaceholder);
}
sb.append(glue);
}
return sb.delete(sb.length() - glue.length(), sb.length()).toString();
}

public static String implode(List<String> items, String separator) {
if (items == null || items.isEmpty()) {
return null;
}
String delimiter = "";
StringBuilder builder = new StringBuilder();
for (String item : items) {
builder.append(delimiter).append(item);
delimiter = separator;
}
return builder.toString();
}

Use this simple function:
private String my_implode(String spacer, String[] in_array){
String res = "";
for (int i = 0 ; i < in_array.length ; i++) {
if (!res.equals("")) {
res += spacer;
}
res += in_array[i];
}
return res;
}
Use:
data_arr = {"d1", "d2", "d3"};
your_imploded_text = my_implode(",", data_arr);
// Output: your_imploded_text = "d1,d2,d3"