Java从url字符串中提取子字符串

Question

I want to extract substring from a url string. This is the url:

  https://test.tech.com/public/pi?id=635106391297495358_0_280740c3f281419b954b309b45a41d77-M_M_0_56b6f628b90b4146abbdba1de9095657

I want to start extracting from id=

  635106391297495358_0_280740c3f281419b954b309b45a41d77

until dash (-), and then extract the remaining substring

  M_M_0_56b6f628b90b4146abbdba1de9095657

Note that the exact domain is not the one in the above, that's just an example .

Any ideas? I would gladly appreciate your help. Thanks.

UPDATE:

this is what I've done so far:

  final URI uri = URI.create(result.getContents());
                    final String path = uri.getPath();
                    path.substring(path.lastIndexOf('-') + 1);
                    Log.e("EXTRACTED", "" + path);

But it just gets public/pi.

Answer 1

First of all, uri.getPath() returns the path component, but what you're looking for is after the ?, so what you might want to try instead is uri.getQuery() .

As for the matching:

Pattern p = Pattern.compile("id=(.+?)-");
Matcher m = p.matcher(uri.getQuery());
if (m.find()) {
    System.out.println(m.group(1));
}

Not tested, but I think it should work. The (.+?) is a capturing group that tries to match characters between the id= and the - .

Answer 2

One major problem is that:

 path.substring(path.lastIndexOf('-') + 1);

will not modify the variable path. The reason is that String are immutable and any change to them create a new string internally. If you want to get hold of the new substring reference then you need to assign it back to path :

 path = path.substring(path.lastIndexOf('-') + 1);

Now you can try more substring options

Answer 3

final URI uri = URI.create("https://test.tech.com/public/pi?id=635106391297495358_0_280740c3f281419b954b309b45a41d77-M_M_0_56b6f628b90b4146abbdba1de9095657");
    String queryString = uri.getQuery(); 
    String subString =  queryString.substring(queryString.lastIndexOf('-') + 1);
    System.out.println("EXTRACTED " + subString);

Produces:

EXTRACTED M_M_0_56b6f628b90b4146abbdba1de9095657

Answer 4

Here is the solution, which I hope is self explanatory:

public static void main(String[] argv) {
    final String uriStr = "https://test.tech.com/public/pi?id=635106391297495358_0_280740c3f281419b954b309b45a41d77-M_M_0_56b6f628b90b4146abbdba1de9095657";
    final URI uri = URI.create(uriStr);
    final String query = uri.getQuery();
    System.out.println(String.format("EXTRACTED QUERY [%s]", query));
    final String part1 = query.substring(query.indexOf('=')+1, query.indexOf('-'));
    System.out.println(String.format("EXTRACTED PART 1 [%s]", part1));
    final String part2 = query.substring(query.indexOf('-')+1);
    System.out.println(String.format("EXTRACTED PART 2 [%s]", part2));
}

}*

Here is the output: EXTRACTED QUERY [id=635106391297495358_0_280740c3f281419b954b309b45a41d77-M_M_0_56b6f628b90b4146abbdba1de9095657]

EXTRACTED PART 1 [635106391297495358_0_280740c3f281419b954b309b45a41d77]

EXTRACTED PART 2 [M_M_0_56b6f628b90b4146abbdba1de9095657]