Android APIs
public class

UriMatcher

extends Object
java.lang.Object
   ↳ android.content.UriMatcher

Class Overview

Utility class to aid in matching URIs in content providers.

To use this class, build up a tree of UriMatcher objects. For example:

    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(UriMatcher.NO_MATCH);

    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);
    }

Starting from API level JELLY_BEAN_MR2, paths can start with a leading slash. For example:

        sURIMatcher.addURI("contacts", "/people", PEOPLE);

Then when you need to match against a URI, call match(Uri), providing the URL that you have been given. 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 that you would otherwise need. For example:

    public String getType(Uri url)
    {
        int match = sURIMatcher.match(url);
        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(Uri url)
    {
        List pathSegments = url.getPathSegments();
        if (pathSegments.size() >= 2) {
            if ("people".equals(pathSegments.get(1))) {
                if (pathSegments.size() == 2) {
                    return "vnd.android.cursor.dir/person";
                } else if (pathSegments.size() == 3) {
                    return "vnd.android.cursor.item/person";
... snip ...
                    return "vnd.android.cursor.dir/snail-mail";
                } else if (pathSegments.size() == 3) {
                    return "vnd.android.cursor.item/snail-mail";
                }
            }
        }
        return null;
    }

Summary

Constants
int NO_MATCH
Public Constructors
UriMatcher(int code)
Creates the root node of the URI tree.
Public Methods
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.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final int NO_MATCH

Added in API level 1

Constant Value: -1 (0xffffffff)

Public Constructors

public UriMatcher (int code)

Added in API level 1

Creates the root node of the URI tree.

Parameters
code the code to match for the root URI

Public Methods

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

Added in API level 1

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.

Starting from API level JELLY_BEAN_MR2, this method will accept a leading slash in the path.

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.

public int match (Uri uri)

Added in API level 1

Try to match against the path in a url.

Parameters
uri The url whose path we will match against.
Returns
int The code for the matched node (added using addURI), or -1 if there is no matched node.