简化后的代码
public final int match(String action, String type, String scheme,
Uri data, Set<String> categories, String logTag) {
if (action != null && !matchAction(action)) {
return NO_MATCH_ACTION;
}
int dataMatch = matchData(type, scheme, data);
if (dataMatch < 0) {
return dataMatch;
}
String categoryMismatch = matchCategories(categories);
if (categoryMismatch != null) {
return NO_MATCH_CATEGORY;
}
return dataMatch;
}代码
/**
* Match this filter against an Intent‘s action. If the filter does not
* specify any actions, the match will always fail.
*
* @param action The desired action to look for.
*
* @return True if the action is listed in the filter.
*/
public final boolean matchAction(String action) {
return hasAction(action);
}
public final boolean hasAction(String action) {
return action != null && mActions.contains(action);
}代码
/**
* Match this filter against an Intent‘s data (type, scheme and path). If
* the filter does not specify any types and does not specify any
* schemes/paths, the match will only succeed if the intent does not
* also specify a type or data. If the filter does not specify any schemes,
* it will implicitly match intents with no scheme, or the schemes "content:"
* or "file:" (basically performing a MIME-type only match). If the filter
* does not specify any MIME types, the Intent also must not specify a MIME
* type.
*
* <p>Be aware that to match against an authority, you must also specify a base
* scheme the authority is in. To match against a data path, both a scheme
* and authority must be specified. If the filter does not specify any
* types or schemes that it matches against, it is considered to be empty
* (any authority or data path given is ignored, as if it were empty as
* well).
*
* <p><em>Note: MIME type, Uri scheme, and host name matching in the
* Android framework is case-sensitive, unlike the formal RFC definitions.
* As a result, you should always write these elements with lower case letters,
* and normalize any MIME types or Uris you receive from
* outside of Android to ensure these elements are lower case before
* supplying them here.</em></p>
*
* @param type The desired data type to look for, as returned by
* Intent.resolveType().
* @param scheme The desired data scheme to look for, as returned by
* Intent.getScheme().
* @param data The full data string to match against, as supplied in
* Intent.data.
*
* @return Returns either a valid match constant (a combination of
* {@link #MATCH_CATEGORY_MASK} and {@link #MATCH_ADJUSTMENT_MASK}),
* or one of the error codes {@link #NO_MATCH_TYPE} if the type didn‘t match
* or {@link #NO_MATCH_DATA} if the scheme/path didn‘t match.
*
* @see #match
*/
public final int matchData(String type, String scheme, Uri data) {
final ArrayList<String> types = mDataTypes;
final ArrayList<String> schemes = mDataSchemes;
int match = MATCH_CATEGORY_EMPTY;
//1. 若filter的type scheme为空，且intent的type data也为空则匹配
// 否则不匹配
if (types == null && schemes == null) {
return ((type == null && data == null)
? (MATCH_CATEGORY_EMPTY+MATCH_ADJUSTMENT_NORMAL) : NO_MATCH_DATA);
}
if (schemes != null) {
//2. 若filter的schemes不为空且intent的scheme包含在里面则进行后续判断；
// 否则不匹配
if (schemes.contains(scheme != null ? scheme : "")) {
match = MATCH_CATEGORY_SCHEME;
} else {
return NO_MATCH_DATA;
}
final ArrayList<PatternMatcher> schemeSpecificParts = mDataSchemeSpecificParts;
if (schemeSpecificParts != null) {
//3. 若schemeSpecificParts不为空，则用data的SchemeSpecificPart来做匹配
// 并修改match的值。uri语法：[scheme:]scheme-specific-part[#fragment] / [scheme:][//authority][path][?query][#fragment]
match = hasDataSchemeSpecificPart(data.getSchemeSpecificPart())
? MATCH_CATEGORY_SCHEME_SPECIFIC_PART : NO_MATCH_DATA;
}
if (match != MATCH_CATEGORY_SCHEME_SPECIFIC_PART) {
// If there isn‘t any matching ssp, we need to match an authority.
final ArrayList<AuthorityEntry> authorities = mDataAuthorities;
// 4. 若schemeSpecificPart(ssp)不匹配，则要匹配authority
// 也就是判断host port部分
if (authorities != null) {
int authMatch = matchDataAuthority(data);
if (authMatch >= 0) {
// 5. host port匹配，则继续进行path的匹配
final ArrayList<PatternMatcher> paths = mDataPaths;
if (paths == null) {
match = authMatch;
} else if (hasDataPath(data.getPath())) {
match = MATCH_CATEGORY_PATH;
} else {
return NO_MATCH_DATA;
}
} else {
// host port不匹配
return NO_MATCH_DATA;
}
}
}
// If neither an ssp nor an authority matched, we‘re done.
if (match == NO_MATCH_DATA) {
return NO_MATCH_DATA;
}
} else {
// filter的schemeSpecificParts不为空且和intent的SchemeSpecificPart匹配时，
// 若scheme不是"" "content" "file" 就不匹配；否则继续后续判断
// Special case: match either an Intent with no data URI,
// or with a scheme: URI. This is to give a convenience for
// the common case where you want to deal with data in a
// content provider, which is done by type, and we don‘t want
// to force everyone to say they handle content: or file: URIs.
if (scheme != null && !"".equals(scheme)
&& !"content".equals(scheme)
&& !"file".equals(scheme)) {
return NO_MATCH_DATA;
}
}
if (types != null) {
// 6. type即MIME
// 若type不为空则判断filter和intent的type是否包容，否则不匹配
if (findMimeType(type)) {
match = MATCH_CATEGORY_TYPE;
} else {
return NO_MATCH_TYPE;
}
} else {
// If no MIME types are specified, then we will only match against
// an Intent that does not have a MIME type.
if (type != null) {
// 若filter的types集合是空，但intent的不是空，不匹配
return NO_MATCH_TYPE;
}
}
return match + MATCH_ADJUSTMENT_NORMAL;
}代码
/**
* Match this filter against an Intent‘s categories. Each category in
* the Intent must be specified by the filter; if any are not in the
* filter, the match fails.
*
* @param categories The categories included in the intent, as returned by
* Intent.getCategories().
*
* @return If all categories match (success), null; else the name of the
* first category that didn‘t match.
*/
public final String matchCategories(Set<String> categories) {
if (categories == null) {
return null;//匹配成功
}
Iterator<String> it = categories.iterator();
if (mCategories == null) {//filter没有Categories；intent有则失败，无则成功
return it.hasNext() ? it.next() : null;
}
while (it.hasNext()) {//filter有Categories, intent的Categories要全部包含在filter里才算成功
final String category = it.next();
if (!mCategories.contains(category)) {
return category;
}
}
return null;
}版权声明：本文为博主原创文章，未经博主允许不得转载。
原文地址：http://blog.csdn.net/cheyiliu/article/details/47323065
