What's the easiest way to break this String down to key/value strings in Java for Android?

Question

Here is my String:

&username=john&password=12345&email=john@go.com

What is the best and most efficient way to break this down into key/value strings so that they can be added as params. Here's a mock example of what I need:

for (set in array)
{
   params.add(new BasicNameValuePair(set.key, set.value));
}

Where did those strings come from? Are they *actually* part of a query string? If so, you should use something which understands query strings (performing all appropriate unescaping etc). — Jon Skeet, Jul 18 '12 at 19:12
Yes, it's a query string from a 3rd party source. Is there some special way to break those down? — Ethan Allen, Jul 18 '12 at 19:15

score 2 · Accepted Answer · answered Jul 18 '12 at 19:16

Do this:

String all = "&username=john&password=12345&email=john@go.com";
//Split across all instances of the 'and' symbol
String[] keyValueConcat = all.split("&");
Map<String, String> kvPairs = new HashMap<String, String>();
for (String concat : keyValueConcat) {
    if (concat.contains("=") {
        //For any string in the split that contains an equals sign
        //Split over the equals sign and add to the map
        String[] keyValueSplit = concat.split("=", 2);
        kvPairs.put(keyValueSplit[0], keyValueSplit[1];
    }
}

And the map kvPairs should contain what you need.

score 2 · Answer 2 · edited May 23 '17 at 12:15

2

See this question: Parsing query strings on Android

On Android, the Apache libraries provide a Query parser:

http://developer.android.com/reference/org/apache/http/client/utils/URLEncodedUtils.html

http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/client/utils/URLEncodedUtils.html

edited May 23 '17 at 12:15

Community

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answered Jul 18 '12 at 19:17

Alex W

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score 0 · Answer 3 · answered Jul 18 '12 at 19:12

0

You can use either StringTokenizer (or) String.split for this purpose.

answered Jul 18 '12 at 19:12

kosa

65,990
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score 0 · Answer 4 · answered Jul 18 '12 at 19:23

String exp="&username=john&password=12345&email=john@go.com"
String[] pairs=exp.split("&");
String[] temp;
Map<String, String> myMap= new HashMap<String, String>();

for(i=0;i<pairs.length;i++){
temp=pairs[i].split("=");
myMap.put(temp[0],temp[1]);

}

score 0 · Answer 5 · answered Jan 21 '16 at 07:16

Not sure if it is available in java for android but in Java 8 a string can be broken into key value pair using below:

String string = "&username=john&password=12345&email=john@go.com";
Map<String, String> map= Stream.of(string.split("&")).map(p->p.split("=")).filter(p->p!=null && p.length==2).collect(Collectors.toMap(p->p[0], p->p[1]));

What's the easiest way to break this String down to key/value strings in Java for Android?

5 Answers5