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regular expression to replaceall substrings embedded in open curling brackets and followed by equal sign and digits

In the follwing String
String toBeFormatted= "[[LngLatAlt{longitude=-7.125924901999952, latitude=33.831783175000055, altitude=NaN},
LngLatAlt{longitude=-5.401396163999948, latitude=35.92213140900003, altitude=NaN}]]"
1- I need to replace all "LngLatAlt{longitude=" with open bracket "["
2- also need to replace all the intermediate ", latitude=33.831783175000055, altitude=NaN}" with ",33.831783175000055]"
That way my string result :
"[[[-7.125924901999952,33.831783175000055],[-5.401396163999948,35.92213140900003]]]"
try it the following reg exp :
String regexTarget = "(\\[\\[LngLatAlt\\{longitude=)";
toBeFormatted.replaceAll(regexTarget, "\\[\\[\\[");
String regexTarget0 = "(, altitude=NaN\\}, LngLatAlt\\{longitude=)";
toBeFormatted.replaceAll(regexTarget0, "],\\[");
String regexTarget1 = "(, latitude=)";
toBeFormatted.replaceAll(regexTarget1, " ,");
String regexTarget2 = "(, altitude=NaN\\})";
toBeFormatted.replaceAll(regexTarget2, "]");
but it seems not working.
Thank you for your help.

try something like:
String result = toBeFormatted.replaceAll("LngLatAlt\\{longitude=([^,]+), latitude=([^,]+), ([^}]+)\\}", "[$1, $2]");
System.out.println(result);

Java-8 - replacing "?" character from the start of a Optional.of(String)

I'm trying to replace "?" character or delete it if my string start with ?. I tested this code and it doesn't work:
Optional<String> stringvalue = Optional.of("?test1=search&test2=ok&test3=hello");
String parameterName = "test1";
if( stringvalue.get().startsWith("?") ){
stringvalue.get().replaceFirst("\\?", "");
}
System.out.println(stringvalue.get());

You can use Optional.map as well:
stringvalue = stringvalue.map( (s) -> s.startsWith("?") ? s.replaceFirst("\\?", "") : s );

The answer is in the comment of #Aominè but how? I think you have to use :
if (stringvalue.get().startsWith("?")) {
stringvalue = Optional.of(stringvalue.get().replaceFirst("\\?", ""));
// ^^^^^^^^^^^-------note this
}
Or just :
stringvalue = Optional.of(stringvalue.get().replaceFirst("^\\?", ""));
//------------^^^^^^^^^^^---------------------------------^

Strings are immutable in Java. So stringvalue.get().replaceFirst("\\?", ""); leaves the original String value unchanged. You need to store the result of the replacement like this:
String parameterName = stringvalue.get().replaceFirst("\\?", "");
Also note that you can use ^ avoiding to test if the string startsWith ?:
String parameterName = stringvalue.get().replaceFirst("^\\?", "");

java find and replace %

In java 1.8.0
I am trying to replace %, but it is not matching
String str = "%28Sample text%29";
str.replaceAll("%29", "\\)");
str.replaceAll("%28", "\\(");
System.out.println("Replaced string is " + str);
I have tried all this Replace symbol "%" with word "Percent" Nothing worked for me. Thanks in Advance.

It's working.
You need re-assign to str
str = str.replaceAll("%29", "\\)");
str = str.replaceAll("%28", "\\(");

Jerry06's answer is correct.
But you could do this simply by using URLDecoder to decode those unicode value.
String s = "%28Hello World!%29";
s = URLDecoder.decode(s, "UTF-8");
System.out.println(s);
Will output :
(Hello World!)

The problem is that you misunderstood the usage of replaceall. It's for regex based replacements. What you need to use is the normal replace method like that:
String str = "%28Sample text%29";
str=str.replace("%29", "\\)"). replace("%28", "\\(");
System.out.println("Replaced string is " + str);

removing space before new line in java

i have a space before a new line in a string and cant remove it (in java).
I have tried the following but nothing works:
strToFix = strToFix.trim();
strToFix = strToFix.replace(" \n", "");
strToFix = strToFix.replaceAll("\\s\\n", "");

myString.replaceAll("[ \t]+(\r\n?|\n)", "$1");
replaceAll takes a regular expression as an argument. The [ \t] matches one or more spaces or tabs. The (\r\n?|\n) matches a newline and puts the result in $1.

try this:
strToFix = strToFix.replaceAll(" \\n", "\n");
'\' is a special character in regex, you need to escape it use '\'.

I believe with this one you should try this instead:
strToFix = strToFix.replace(" \\n", "\n");
Edit:
I forgot the escape in my original answer. James.Xu in his answer reminded me.

Are you sure?
String s1 = "hi ";
System.out.println("|" + s1.trim() + "|");
String s2 = "hi \n";
System.out.println("|" + s2.trim() + "|");
prints
|hi|
|hi|

are you sure it is a space what you're trying to remove? You should print string bytes and see if the first byte's value is actually a 32 (decimal) or 20 (hexadecimal).

trim() seems to do what your asking on my system. Here's the code I used, maybe you want to try it on your system:
public class so5488527 {
public static void main(String [] args)
{
String testString1 = "abc \n";
String testString2 = "def \n";
String testString3 = "ghi \n";
String testString4 = "jkl \n";
testString3 = testString3.trim();
System.out.println(testString1);
System.out.println(testString2.trim());
System.out.println(testString3);
System.out.println(testString4.trim());
}
}

How to remove " " from java string

I have a java string with " " from a text file the program accesses with a Buffered Reader object. I have tried string.replaceAll(" ","") and it doesn't seem to work.
Any ideas?
cleaned = cleaned.replace(" "," ");

cleaned = cleaned.replace("\u00a0","")

This is a two step process:
strLineApp = strLineApp.replaceAll("&"+"nbsp;", " ");
strLineApp = strLineApp.replaceAll(String.valueOf((char) 160), " ");
This worked for me. Hope it helps you too!

The same way you mentioned:
String cleaned = s.replace(" "," ");
It works for me.

There's a ready solution to unescape HTML from Apache commons:
StringEscapeUtils.unescapeHtml("")
You can also escape HTML if you want:
StringEscapeUtils.escapeHtml("")

Strings are immutable so You need to do
string = string.replaceAll(" ","")

You can use JSoup library:
String date = doc.body().getElementsByClass("Datum").html().toString().replaceAll(" ","").trim();

String.replace(char, char) takes char inputs (or CharSequence inputs)
String.replaceAll(String, String) takes String inputs and matches by regular expression.
For example:
String origStr = "bat";
String newStr = str.replace('a', 'i');
// Now:
// origStr = "bat"
// newStr = "bit"
The key point is that the return value contains the new edited String. The original String variable that invokes replace()/replaceAll() doesn't have its contents changed.
For example:
String origStr = "how are you?";
String newStr = origStr.replaceAll(" "," ");
String anotherStr = origStr.replaceAll(" ","");
// origStr = "how are you?"
// newStr = "how are you?"
// anotherStr = howareyou?"

We can have a regular expression check and replace HTML nbsp;
input.replaceAll("[\\s\\u00A0]+$", "") + "");
It removes non breaking spaces in the input string.

My solution is the following, and only this worked for me:
String string = stringWithNbsp.replaceAll("NNBSP", "");

Strings in Java are immutable. You have to do:
String newStr = cleaned.replaceAll(" ", "");

I encountered the same problem: The inner HTML of the element I needed had "&nbsp" and my assertion failed.
Since the question has not accepted any answer,yet I would suggest the following, which worked for me
String string = stringwithNbsp.replaceAll("\n", "");
P.S : Happy testing :)