深入分析Intent匹配查詢
發表時(shí)間：2020-11-5
發布人(rén)：融晨科技
浏覽次數：45
尊崇本創兇http://blog.csdn.net/yuanzeyao/article/details/42243583
正在(zài)前裏的(de)一沃那粕拘，我麽宏細闡發了(le／liǎo)PackageManagerService的(de)娼過程(正在(zài)背狼９依φ谥那粕拘，爲(wéi / wèi)了(le／liǎo)便當，我會粗PackageManagerService簡稱PMS)，PMS正在(zài)平的(de)過程中，會來(lái)膳體系app跟映收拆置的(de)app，而(ér)後粗那些app的(de)疑密保存迪蘋皓肥據機閉中，正在(zài)那篇沃那粕拘，我們會接族诎辣郴沃那啓持絕闡發Intent婚配抽芽過程，如出(chū)有雅對PMS出(chū)有是(shì)很生悉的(de)同窗倡議先來(lái)掃瞄前辣郴沃那啓PackageManagerService平過程闡發。
做爲(wéi / wèi)一名Android App斥地(dì / de)着棘喂好你對Intent的(de)利用實臨生悉出(chū)庸凝了(le／liǎo)，比方我念正在(zài)一個(gè)Activity中平别的(de)一個(gè)Activity,會利用來(lái)郝代亂孀
Intent intent=new Intent(this,SecondActivity.class); this.startActivity(intent);
以(yǐ)梢法稱慰吸示Intent調用，誠然逢供時(shí)辰我們會利用隐式Intent，比方兇
Intent intent=new Intent("com.android.demo");
this.startActivity(intent);果爲(wéi / wèi)Intent的(de)利用同常複純，所以(yǐ)正在(zài)那裏我出(chū)有念再來(lái)花太多光丫淮描繪它了(le／liǎo)，我們那老是(shì)要(yào / yāo)哪當ツ倒源碌濫角度來(lái)懂裏經過過程Intent是(shì)如何婚配Acitivity的(de)(Service,Receiver講理也(yě)是(shì)好出(chū)有逗媚)。
我們曲接哪當ツ倒startActivity函肥初步伴(提示兇我利用的(de)是(shì)4.1源碼，出(chū)有卑版本的(de)源碼話苄些收收)，正在(zài)那裏，先給出(chū)一張時(shí)序圖，而(ér)後跟着時(shí)序圖源碼。
[img]http://img.blog.csdn.net/20141229214350896?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveXVhbnpleWFv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
圖1-1
目據圖1-1，當我們調用Activity的(de)startActivity辦房啾，實正在(zài)調用的(de)便是(shì)調用ContextImpl的(de)startActivity辦法
public void startActivity(Intent intent, Bundle options) {
if ((intent.getFlags()&Intent.FLAG_ACTIVITY_NEW_TASK) == 0) {
throw new AndroidRuntimeException(
"Calling startActivity() from outside of an Activity "
+ " context requires the FLAG_ACTIVITY_NEW_TASK flag."
+ " Is this really what you want?");
}
mMainThread.getInstrumentation().execStartActivity(
getOuterContext(), mMainThread.getApplicationThread(), null,
(Activity)null, intent, -1, options);
}正在(zài)ContextImple的(de)startActivity辦法中，會調用Instrumentation的(de)execStartActivity辦犯，那個(gè)辦法我便出(chū)有揭出(chū)源碼了(le／liǎo)，它琅春沐正在(zài)便是(shì)調用了(le／liǎo)ActivityManagerService的(de)startActivity辦犯，那個(gè)辦法琅春沐正在(zài)便是(shì)調用了(le／liǎo)ActivityStack的(de)startActivityMayWait辦犯，弄辦法逢調用了(le／liǎo)本身的(de)resolveActivity辦犯，末了(le／liǎo)調用了(le／liǎo)PMS的(de)resolveIntent辦法了(le／liǎo)，到(dào)那裏末于(yú)睹到(dào)了(le／liǎo)PMS了(le／liǎo)，正在(zài)resolveIntent辦法琅春沔便是(shì)調用了(le／liǎo)本身的(de)queryIntentActivities辦犯，queryIntentActivities會前來(lái)一個(gè)ActivityInfo東西，我們知講一個(gè)ActivityInfo東西便是(shì)一個(gè)Activity的(de)檔氨長具，記麓嗨一個(gè)Acitivity的(de)全部的(de)疑密〖怯裏給出(chū)queryIntentActivities的(de)源碼
public List<ResolveInfo> queryIntentActivities(Intent intent,
String resolvedType, int flags, int userId) {
if (!sUserManager.exists(userId)) return null;
ComponentName comp = intent.getComponent();
if (comp == null) {
if (intent.getSelector() != null) {
intent = intent.getSelector();
comp = intent.getComponent();
}
}
if (comp != null) {
final List<ResolveInfo> list = new ArrayList<ResolveInfo>(1);
final ActivityInfo ai = getActivityInfo(comp, flags, userId);
if (ai != null) {
final ResolveInfo ri = new ResolveInfo();
ri.activityInfo = ai;
list.add(ri);
}
return list;
}
synchronized (mPackages) {
final String pkgName = intent.getPackage();
if (pkgName == null) {
return mActivities.queryIntent(intent, resolvedType, flags, userId);
}
final PackageParser.Package pkg = mPackages.get(pkgName);
if (pkg != null) {
// C
return mActivities.queryIntentForPackage(intent, resolvedType, flags,
pkg.activities, userId);
}
return new ArrayList<ResolveInfo>();
}
}對膳春沔的(de)代碼，可能看出(chū):
如出(chū)有雅Intent 指渾跋扈了(le／liǎo)然Componet，那孟副接經過過程Componet便可能找到(dào)ActivityInfo
如出(chū)有遜矢定了(le／liǎo)packagename,那麽可以(yǐ)經過過程packagename找到(dào)Package,而(ér)後經過過程Package包露的(de)Activities中盡鋅配
如出(chū)有雅緊出(chū)有滿足，那夢孰要(yào / yāo)齊體系盡鋅配。
寫到(dào)那裏，我黴┬須要(yào / yāo)對殺郴沃那粕拘的(de)一皓緊張肥據機閉盡鋅念。
回念1兇PackageManagerService中有兩個(gè)scanPackageLI，第一個(gè)scanPackageLI的(de)第一個(gè)好肥是(shì)File,它的(de)任務便是(shì)粗指定的(de)文取(apk)的(de)AndroidManifest.xml文取分解成PackageParser.Package東西。我們看看那個(gè)東西有藏些字段伴
[img]http://img.blog.csdn.net/20141229221514312?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveXVhbnpleWFv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
圖1-2
那裏我僅僅列出(chū)了(le／liǎo)比較重依閱字段，疑好哪當ツ倒家看了(le／liǎo)背龊喜鹱，Package琅春沔存儲了(le／liǎo)一個(gè)apk中的(de)全部疑密，此末露全部的(de)Activity,全部的(de)Service等底箧膦且正在(zài)PMS中有一個(gè)HashMap保存了(le／liǎo)全部的(de)Pacakge,此中key便是(shì)包名
回念2Ｎ第兩個(gè)scanPackageLI中，會粗指定Package中的(de)一皓疑密盡洩墨湧，比方會粗activities中的(de)全部Activity好加ActivityIntentResolver範例的(de)鄙mActivities鄙中〈圄意那裏道(dào)的(de)Activity跟我們平常平但凡用的(de)Activity出(chū)有是(shì)一個(gè)範例，它的(de)持絕機閉來(lái)郝兇
[img]http://img.blog.csdn.net/20141229224156659?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveXVhbnpleWFv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
圖1-3
回念3ＮscanPackageLI中，經過過程調用ActivityIntentResolver的(de)addActivity辦犯，粗指定的(de)PackageParser.Activity保磁揀來(lái)，我們看看addActivity做兩如何。
/**
* @param a
* 要(yào / yāo)被保存的(de)Activity
* @param type
* "activity" or "recevier"
*/
public final void addActivity(PackageParser.Activity a, String type) {
final boolean systemApp = isSystemApp(a.info.applicationInfo);
//保存迪蘋個(gè)HashMap中
mActivities.put(a.getComponentName(), a);
final int NI = a.intents.size();
//遍曆Activity中全部的(de)IntentFilter,而(ér)後調用addFilter辦法盡行保存
for (int j=0; j<NI; j++) {
PackageParser.ActivityIntentInfo intent = a.intents.get(j);
if (!systemApp && intent.getPriority() > 0 && "activity".equals(type)) {
intent.setPriority(0);
Log.w(TAG, "Package " + a.info.applicationInfo.packageName + " has activity "
+ a.className + " with priority > 0, forcing to 0");
}
if (DEBUG_SHOW_INFO) {
Log.v(TAG, " IntentFilter:");
intent.dump(new LogPrinter(Log.VERBOSE, TAG), " ");
}
if (!intent.debugCheck()) {
Log.w(TAG, "==> For Activity " + a.info.name);
}
addFilter(intent);
}
}
邏輯比較複純，曲接盡進addFilter函肥，看看做烈姗甚麽
public void addFilter(F f) {
mFilters.add(f);
int numS = register_intent_filter(f, f.schemesIterator(),
mSchemeToFilter, " Scheme: ");
int numT = register_mime_types(f, " Type: ");
if (numS == 0 && numT == 0) {
register_intent_filter(f, f.actionsIterator(),
mActionToFilter, " Action: ");
}
if (numT != 0) {
register_intent_filter(f, f.actionsIterator(),
mTypedActionToFilter, " TypedAction: ");
}
}此中mFilters是(shì)一個(gè)HashSet範例鄙，那個(gè)辦法尾俠粗ActivityIntentInfo範例鄙保存到(dào)mFilters中，接着調用了(le／liǎo)register_intent_filter辦法
private final int register_intent_filter(F filter, Iterator<String> i,
HashMap<String, ArrayList<F>> dest, String prefix) {
if (i == null) {
return 0;
}
int num = 0;
while (i.hasNext()) {
String name = i.next();
num++;
if (localLOGV) Slog.v(TAG, prefix + name);
ArrayList<F> array = dest.get(name);
if (array == null) {
//Slog.v(TAG, "Creating new array for " + name);
array = new ArrayList<F>();
dest.put(name, array);
}
array.add(filter);
}
return num;
}正在(zài)看代碼之(zhī)峭宮必要(yào / yāo)生悉那裏的(de)肥據機閉，filter便蝦帽于(yú)一個(gè)IntentFilter,i 是(shì)一個(gè)叠代器，經過過程它我們可能遍曆filter全部的(de)scheme,dest便是(shì)一個(gè)HashMap，key是(shì)filter的(de)scheme,值便是(shì)一個(gè)ArrayList<F>，實正在(zài)便是(shì)經過過程遍曆一個(gè)IntentFilter的(de)全部scheme，目據那個(gè)scheme找到(dào)洞喀的(de)ArrayList<F>,而(ér)後粗那個(gè)Filter放進ArrayList<F>,而(ér)後前來(lái)scheme的(de)個(gè)肥。
如古回到(dào)addFilter辦犯，接着會帶調用register_mime_types辦犯，一樣，看看那個(gè)辦法做兩如何
private final int register_mime_types(F filter, String prefix) {
final Iterator<String> i = filter.typesIterator();
if (i == null) {
return 0;
}
int num = 0;
while (i.hasNext()) {
String name = i.next();
num++;
if (localLOGV) Slog.v(TAG, prefix + name);
String baseName = name;
final int slashpos = name.indexOf('/');
if (slashpos > 0) {
baseName = name.substring(0, slashpos).intern();
} else {
name = name + "/*";
}
ArrayList<F> array = mTypeToFilter.get(name);
if (array == null) {
//Slog.v(TAG, "Creating new array for " + name);
array = new ArrayList<F>();
mTypeToFilter.put(name, array);
}
array.add(filter);
if (slashpos > 0) {
array = mBaseTypeToFilter.get(baseName);
if (array == null) {
//Slog.v(TAG, "Creating new array for " + name);
array = new ArrayList<F>();
mBaseTypeToFilter.put(baseName, array);
}
array.add(filter);
} else {
array = mWildTypeToFilter.get(baseName);
if (array == null) {
//Slog.v(TAG, "Creating new array for " + name);
array = new ArrayList<F>();
mWildTypeToFilter.put(baseName, array);
}
array.add(filter);
}
}
return num;
}那個(gè)辦法的(de)成不(bù)俗跟register_intent_filter辦繁腸能是(shì)一樣的(de)，隻出(chū)庸凝register_intent_filter是(shì)處理scheme的(de)，那老是(shì)處理type的(de)，type的(de)邏輯比scheme複純。scheme隻用了(le／liǎo)一個(gè)mSchemeToFilter存儲，而(ér)type用了(le／liǎo)三個(gè)，他(tā)們辨别是(shì)兇
mWildTypeToFilter兇用于(yú)保存扇髅了(le／liǎo)Data範例“image/*”的(de)IntentFilter，但是(shì)扇髅“image/jpeg”的(de)出(chū)有算正在(zài)你
mTypeToFilter脅瘘露了(le／liǎo)mWildTypeToFilter和(hé / huò)指渾跋扈了(le／liǎo)然Data範例爲(wéi / wèi)肯侗趁肥的(de)IntentFilter疑密，如“image/jpeg”跟“image/*”範例
mBaseTypeToFilter兇保存MIME中Base範例的(de)IntentFilter,但是(shì)出(chū)誘露Sub type爲(wéi / wèi)"*"的(de)IntentFilter
實正在(zài)膳春沔回系濫3裏緊恃舭辣郴沃那啓擋刳容，下裏便初步研究一下queryIntentActivities的(de)邏輯凹
public List<ResolveInfo> queryIntentActivities(Intent intent,
String resolvedType, int flags, int userId) {
if (!sUserManager.exists(userId)) return null;
ComponentName comp = intent.getComponent();
if (comp == null) {
if (intent.getSelector() != null) {
intent = intent.getSelector();
comp = intent.getComponent();
}
}
if (comp != null) {
final List<ResolveInfo> list = new ArrayList<ResolveInfo>(1);
final ActivityInfo ai = getActivityInfo(comp, flags, userId);
if (ai != null) {
final ResolveInfo ri = new ResolveInfo();
ri.activityInfo = ai;
list.add(ri);
}
return list;
}
// reader
synchronized (mPackages) {
final String pkgName = intent.getPackage();
if (pkgName == null) {
return mActivities.queryIntent(intent, resolvedType, flags, userId);
}
final PackageParser.Package pkg = mPackages.get(pkgName);
if (pkg != null) {
return mActivities.queryIntentForPackage(intent, resolvedType, flags,
pkg.activities, userId);
}
return new ArrayList<ResolveInfo>();
}
}
那朝分代碼邏輯實正在(zài)也(yě)出(chū)有算複純，經過過程Intent你到(dào)ComponetName,如出(chū)有雅ComponetName出(chū)無爲(wéi / wèi)null(表明利用的(de)蝕涸尾悴用)，那麽經過過程調用getActivityInfo辦法你到(dào)ActivityInfo。getActivityInfo實正在(zài)便是(shì)到(dào)mActivities琅春沔目據ComponetName你到(dào)PackageParser.Activity東西，并經過過程調用PackageParser.generateActivityInfo辦法粗PackageParser.Activity東西變成ActivityInfo東西。如出(chū)有雅ComponetName爲(wéi / wèi)null(隐尾悴用),那麽便要(yào / yāo)分爲(wéi / wèi)兩種環境兇
第腋Ｖ環境兇經過過程intent你到(dào)包名爲(wéi / wèi)Null,那麽調用ActivityIntentResolver的(de)queryIntent辦法
public List<ResolveInfo> queryIntent(Intent intent, String resolvedType,
boolean defaultOnly, int userId) {
if (!sUserManager.exists(userId)) return null;
mFlags = defaultOnly ? PackageManager.MATCH_DEFAULT_ONLY : 0;
return super.queryIntent(intent, resolvedType, defaultOnly, userId);
}代碼很少，調用了(le／liǎo)IntentResolver的(de)queryIntent，曲接看queryIntent的(de)源碼伴
public List<R> queryIntent(Intent intent, String resolvedType, boolean defaultOnly,
int userId) {
String scheme = intent.getScheme();
ArrayList<R> finalList = new ArrayList<R>();
final boolean debug = localLOGV ||
((intent.getFlags() & Intent.FLAG_DEBUG_LOG_RESOLUTION) != 0);
if (debug) Slog.v(
TAG, "Resolving type " + resolvedType + " scheme " + scheme
+ " of intent " + intent);
ArrayList<F> firstTypeCut = null;
ArrayList<F> secondTypeCut = null;
ArrayList<F> thirdTypeCut = null;
ArrayList<F> schemeCut = null;
// If the intent includes a MIME type, then we want to collect all of
// the filters that match that MIME type.
if (resolvedType != null) {
int slashpos = resolvedType.indexOf('/');
if (slashpos > 0) {
final String baseType = resolvedType.substring(0, slashpos);
if (!baseType.equals("*")) {
if (resolvedType.length() != slashpos+2
|| resolvedType.charAt(slashpos+1) != '*') {
// Not a wild card, so we can just look for all filters that
// completely match or wildcards whose base type matches.
firstTypeCut = mTypeToFilter.get(resolvedType);
if (debug) Slog.v(TAG, "First type cut: " + firstTypeCut);
secondTypeCut = mWildTypeToFilter.get(baseType);
if (debug) Slog.v(TAG, "Second type cut: " + secondTypeCut);
} else {
// We can match anything with our base type.
firstTypeCut = mBaseTypeToFilter.get(baseType);
if (debug) Slog.v(TAG, "First type cut: " + firstTypeCut);
secondTypeCut = mWildTypeToFilter.get(baseType);
if (debug) Slog.v(TAG, "Second type cut: " + secondTypeCut);
}
// Any */* types always apply, but we only need to do this
// if the intent type was not already */*.
thirdTypeCut = mWildTypeToFilter.get("*");
if (debug) Slog.v(TAG, "Third type cut: " + thirdTypeCut);
} else if (intent.getAction() != null) {
// The intent specified any type ({@literal *}/*). This
// can be a whole heck of a lot of things, so as a first
// cut let's use the action instead.
firstTypeCut = mTypedActionToFilter.get(intent.getAction());
if (debug) Slog.v(TAG, "Typed Action list: " + firstTypeCut);
}
}
}
// If the intent includes a data URI, then we want to collect all of
// the filters that match its scheme (we will further refine matches
// on the authority and path by directly matching each resulting filter).
if (scheme != null) {
schemeCut = mSchemeToFilter.get(scheme);
if (debug) Slog.v(TAG, "Scheme list: " + schemeCut);
}
// If the intent does not specify any data -- either a MIME type or
// a URI -- then we will only be looking for matches against empty
// data.
if (resolvedType == null && scheme == null && intent.getAction() != null) {
firstTypeCut = mActionToFilter.get(intent.getAction());
if (debug) Slog.v(TAG, "Action list: " + firstTypeCut);
}
FastImmutableArraySet<String> categories = getFastIntentCategories(intent);
if (firstTypeCut != null) {
buildResolveList(intent, categories, debug, defaultOnly,
resolvedType, scheme, firstTypeCut, finalList, userId);
}
if (secondTypeCut != null) {
buildResolveList(intent, categories, debug, defaultOnly,
resolvedType, scheme, secondTypeCut, finalList, userId);
}
if (thirdTypeCut != null) {
buildResolveList(intent, categories, debug, defaultOnly,
resolvedType, scheme, thirdTypeCut, finalList, userId);
}
if (schemeCut != null) {
buildResolveList(intent, categories, debug, defaultOnly,
resolvedType, scheme, schemeCut, finalList, userId);
}
sortResults(finalList);
if (debug) {
Slog.v(TAG, "Final result list:");
for (R r : finalList) {
Slog.v(TAG, " " + r);
}
}
return finalList;
}
那個(gè)函肥看起來(lái)很複純，但是(shì)邏輯很複純，我正在(zài)那裏複純的(de)汨繪一下。
尾銑桤出(chū)有雅給定的(de)Intent包露MIME，便的(de)膳春沔(mTypeToFilter,mWildTypeToFilter,mBaseTypeToFilter)琅訣春譏瘧編符前提的(de)IntentFilter,粗膠匣有雅辨别保存到(dào)firstTypeCut，secondTypeCut，thirdTypeCut中，而(ér)後目據scheme盡鋅配，粗膠匣有雅保存到(dào)schemeCut，末了(le／liǎo)調用buildResolveList辦犯，粗action,scheme,categories等成分随後婚配，粗膠匣有雅保存到(dào)finalList中來(lái)，末了(le／liǎo)對finalList盡幸膳序〖欠曛環境闡發完了(le／liǎo)。
第兩種環境兇如出(chū)有雅intent中的(de)包名出(chū)無爲(wéi / wèi)Null，目據包名你到(dào)PackageParser.Package東西，調用ActivityIntentResolver的(de)queryIntentForPackage辦犯４可，此辦法中遍曆PackageParsr.Package中的(de)mactivities東西，粗每個(gè)PackageParser.Activity中的(de)全部IntentFilter好加listCut(一個(gè)ArrayList)中，而(ér)後調用IntentResolve的(de)queryIntentFromList辦犯，正在(zài)queryIntentFromList辦法中，目據給定的(de)Intent的(de)action,categories,scheme,type等疑密婚配listCut中的(de)IntentFilter東西。
好了(le／liǎo)閉于(yú)Intent的(de)妤配過程便寫到(dào)那爛埽
