public class UriMatcher
extends Object
java.lang.Object | |
↳ | android.content.UriMatcher |
工具类有助于匹配内容提供者中的URI。
要使用这个类,建立一个UriMatcher
对象树。 例如:
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); }
从API级别JELLY_BEAN_MR2
开始,路径可以JELLY_BEAN_MR2
斜杠开始。 例如:
sURIMatcher.addURI("contacts", "/people", PEOPLE);
然后,当您需要与URI进行匹配时,请致电match(Uri)
,提供您已获得的URL。 您可以使用结果来构建查询,返回一个类型,插入或删除一行或任何您需要的内容,而无需重复所有您需要的if-else逻辑。 例如:
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) { ListpathSegments = 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; }
Constants |
|
---|---|
int |
NO_MATCH |
Public constructors |
|
---|---|
UriMatcher(int code) 创建URI树的根节点。 |
Public methods |
|
---|---|
void |
addURI(String authority, String path, int code) 添加要匹配的URI,以及匹配此URI时返回的代码。 |
int |
match(Uri uri) 尝试匹配URL中的路径。 |
Inherited methods |
|
---|---|
From class java.lang.Object
|
UriMatcher (int code)
创建URI树的根节点。
Parameters | |
---|---|
code |
int : the code to match for the root URI |
void addURI (String authority, String path, int code)
添加要匹配的URI,以及匹配此URI时返回的代码。 URI节点可以是完全匹配字符串,与任何文本匹配的标记“*”或仅匹配数字的标记“#”。
从API级别 JELLY_BEAN_MR2
,此方法将接受路径中的前导斜杠。
Parameters | |
---|---|
authority |
String : the authority to match |
path |
String : 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 |
int : the code that is returned when a URI is matched against the given components. Must be positive. |
int match (Uri uri)
尝试匹配URL中的路径。
Parameters | |
---|---|
uri |
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. |