android.content
Class UriMatcher

java.lang.Object
  android.content.UriMatcher

public class UriMatcher
extends Object

Utility class to aid in matching URIs in content providers.

To use this class, build up a tree of UriMatcher objects. Typically, it looks something like this:

    private static final int PEOPLE = 1;
    private static final int PEOPLE_ID = 2;
    private static final int PEOPLE_PHONES = 3;
    private static final int PEOPLE_PHONES_ID = 4;
    private static final int PEOPLE_CONTACTMETHODS = 7;
    private static final int PEOPLE_CONTACTMETHODS_ID = 8;

    private static final int DELETED_PEOPLE = 20;

    private static final int PHONES = 9;
    private static final int PHONES_ID = 10;
    private static final int PHONES_FILTER = 14;

    private static final int CONTACTMETHODS = 18;
    private static final int CONTACTMETHODS_ID = 19;

    private static final int CALLS = 11;
    private static final int CALLS_ID = 12;
    private static final int CALLS_FILTER = 15;

    private static final UriMatcher sURIMatcher = new UriMatcher();

    static
    {
        sURIMatcher.addURI("contacts", "/people", PEOPLE);
        sURIMatcher.addURI("contacts", "/people/#", PEOPLE_ID);
        sURIMatcher.addURI("contacts", "/people/#/phones", PEOPLE_PHONES);
        sURIMatcher.addURI("contacts", "/people/#/phones/#", PEOPLE_PHONES_ID);
        sURIMatcher.addURI("contacts", "/people/#/contact_methods", PEOPLE_CONTACTMETHODS);
        sURIMatcher.addURI("contacts", "/people/#/contact_methods/#", PEOPLE_CONTACTMETHODS_ID);
        sURIMatcher.addURI("contacts", "/deleted_people", DELETED_PEOPLE);
        sURIMatcher.addURI("contacts", "/phones", PHONES);
        sURIMatcher.addURI("contacts", "/phones/filter/*", PHONES_FILTER);
        sURIMatcher.addURI("contacts", "/phones/#", PHONES_ID);
        sURIMatcher.addURI("contacts", "/contact_methods", CONTACTMETHODS);
        sURIMatcher.addURI("contacts", "/contact_methods/#", CONTACTMETHODS_ID);
        sURIMatcher.addURI("call_log", "/calls", CALLS);
        sURIMatcher.addURI("call_log", "/calls/filter/*", CALLS_FILTER);
        sURIMatcher.addURI("call_log", "/calls/#", CALLS_ID);
    }

Then when you need to match match against a URI, call match(android.net.Uri), providing the tokenized url you've been given, and the value you want if there isn't a match. You can use the result to build a query, return a type, insert or delete a row, or whatever you need, without duplicating all of the if-else logic you'd otherwise need. Like this:

    public String getType(String[] url)
    {
        int match = sURIMatcher.match(url, NO_MATCH);
        switch (match)
        {
            case PEOPLE:
                return "vnd.android.cursor.dir/person";
            case PEOPLE_ID:
                return "vnd.android.cursor.item/person";
... snip ...
                return "vnd.android.cursor.dir/snail-mail";
            case PEOPLE_ADDRESS_ID:
                return "vnd.android.cursor.item/snail-mail";
            default:
                return null;
        }
    }

instead of

    public String getType(String[] url)
    {
        if (url.length >= 2) {
            if (url[1].equals("people")) {
                if (url.length == 2) {
                    return "vnd.android.cursor.dir/person";
                } else if (url.length == 3) {
                    return "vnd.android.cursor.item/person";
... snip ...
                    return "vnd.android.cursor.dir/snail-mail";
                } else if (url.length == 3) {
                    return "vnd.android.cursor.item/snail-mail";
                }
            }
        }
        return null;
    }

Field Summary

static int	NO_MATCH
(package private) static Pattern	PATH_SPLIT_PATTERN

Constructor Summary

UriMatcher(int code)
Creates the root node of the URI tree.

Method Summary

void	addURI(String authority, String path, int code) Add a URI to match, and the code to return when this URI is matched.
int	match(Uri uri) Try to match against the path in a url.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NO_MATCH

public static final int NO_MATCH

See Also:

Constant Field Values

PATH_SPLIT_PATTERN

static final Pattern PATH_SPLIT_PATTERN

Constructor Detail

UriMatcher

public UriMatcher(int code)

Creates the root node of the URI tree.

Parameters:

code - the code to match for the root URI

Method Detail

addURI

public void addURI(String authority,
                   String path,
                   int code)

Add a URI to match, and the code to return when this URI is matched. URI nodes may be exact match string, the token "*" that matches any text, or the token "#" that matches only numbers.

Parameters:

authority - the authority to match

path - the path to match. * may be used as a wild card for any text, and # may be used as a wild card for numbers.

code - the code that is returned when a URI is matched against the given components. Must be positive.

match

public int match(Uri uri)

Try to match against the path in a url.

Parameters:

uri - The url whose path we will match against.

Returns:

The code for the matched node (added using addURI), or -1 if there is no matched node.