UriMatcher

https://developer.android.com/reference/android/content/UriMatcher.html

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. 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);
    }
 

URI 节点可以是完全匹配字符串、匹配任何文本的标记“*”或仅匹配数字的标记“#”

Starting from API level Build.VERSION_CODES.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;
        }
    }