aapt的源码在所在的目录:Android/frameworks/base/tools/aapt/。
Main.cpp位置:android-6.0.0_r1/frameworks/base/tools/aapt/Main.cpp
首先查看Main.cpp的main方法:
- int main(int argc, char* const argv[])
- {
- char *prog = argv[0];
- Bundle bundle;
- bool wantUsage = false;
- int result = 1; // pessimistically assume an error.
-
- ...
- //进行资源打包的参数p或package
- else if (argv[1][0] == 'p')
- bundle.setCommand(kCommandPackage);
- ...
-
- /*
- * Pull out flags. We support "-fv" and "-f -v".
- */
- while (argc && argv[0][0] == '-') {
- /* flag(s) found */
- const char* cp = argv[0] +1;
-
- while (*cp != '\0') {
- ...
- //收集appt命令输入的参数,这些参数以"-"开头
- case '-':
- if (strcmp(cp, "-debug-mode") == 0) {
- bundle.setDebugMode(true);
- }
- ...
- break;
- default:
- fprintf(stderr, "ERROR: Unknown flag '-%c'\n", *cp);
- wantUsage = true;
- goto bail;
- }
-
- cp++;
- }
- argc--;
- argv++;
- }
-
- /*
- * We're past the flags. The rest all goes straight in.
- */
- bundle.setFileSpec(argv, argc);
- //根据bundle收集的参数进行资源处理
- result = handleCommand(&bundle);
-
- //输入参数错误时会跳转到此
- bail:
- if (wantUsage) {
- usage();
- result = 2;
- }
-
- return result;
- }
在main函数内,首先创建一个Bundle对象,这个对象用来存储输入的操作类型和相关的参数。argv相当于java中的字符串数组。取该数组的第2个字符串的第一个char值。因为是执行资源打包,所以它是’p’。bundle记录执行类型为kCommandPackage,即资源打包。while循环处理剩余的char数组(即字符串数组),将参数按照类型设置到bundle中。参数解析完毕,则会执行handleCommand(&bundle)。如果在解析输入的参数时出现了错误,便使用goto跳转到bail代码块。在bail代码块中可能会执行usage();,这个方法会打印出aapt所有的命令类型和相关的参数。
先看看usage()函数,省略了与资源打包无关的信息。
- void usage(void)
- {
- ...
- fprintf(stderr,
- " %s p[ackage] [-d][-f][-m][-u][-v][-x][-z][-M AndroidManifest.xml] \\\n"
- " [-0 extension [-0 extension ...]] [-g tolerance] [-j jarfile] \\\n"
- " [--debug-mode] [--min-sdk-version VAL] [--target-sdk-version VAL] \\\n"
- " [--app-version VAL] [--app-version-name TEXT] [--custom-package VAL] \\\n"
- " [--rename-manifest-package PACKAGE] \\\n"
- " [--rename-instrumentation-target-package PACKAGE] \\\n"
- " [--utf16] [--auto-add-overlay] \\\n"
- " [--max-res-version VAL] \\\n"
- " [-I base-package [-I base-package ...]] \\\n"
- " [-A asset-source-dir] [-G class-list-file] [-P public-definitions-file] \\\n"
- " [-S resource-sources [-S resource-sources ...]] \\\n"
- " [-F apk-file] [-J R-file-dir] \\\n"
- " [--product product1,product2,...] \\\n"
- " [-c CONFIGS] [--preferred-density DENSITY] \\\n"
- " [--split CONFIGS [--split CONFIGS]] \\\n"
- " [--feature-of package [--feature-after package]] \\\n"
- " [raw-files-dir [raw-files-dir] ...] \\\n"
- " [--output-text-symbols DIR]\n"
- " [--apk-module moduleName]\n"
- "\n"
- " Package the android resources. It will read assets and resources that are\n"
- " supplied with the -M -A -S or raw-files-dir arguments. The -J -P -F and -R\n"
- " options control which files are output.\n\n"
- , gProgName);
- ...
- }
打印appt执行的操作类型和对应的参数。
先看看handleCommand()函数,
- int handleCommand(Bundle* bundle)
- {
- switch (bundle->getCommand()) {
- case kCommandVersion: return doVersion(bundle);
- ...
- case kCommandPackage: return doPackage(bundle);
- ...
- default:
- fprintf(stderr, "%s: requested command not yet supported\n", gProgName);
- return 1;
- }
- }
在main函数中bundle设置的cmmand类型为kCommandPackage,所以会执行doPackage(bundle)代码。使用操作系统自带的搜索,检索aapt目录内的文件内容’doPackage’。会查找到doPackage()是Command.cpp中的函数。
Command.cpp位置:android-6.0.0_r1/frameworks/base/tools/aapt/Command.cpp
doPackage()函数中处理资源相关的代码:
- int doPackage(Bundle* bundle)
- {
- ...
- // If they asked for any fileAs that need to be compiled, do so.
- if (bundle->getResourceSourceDirs().size() || bundle->getAndroidManifestFile()) {
- err = buildResources(bundle, assets, builder);
- if (err != 0) {
- goto bail;
- }
- }
- ...
- }
继续搜索buildResources()函数所在的文件,查找到Resource.cpp。
Resource.cpp位置:android-6.0.0_r1/frameworks/base/tools/aapt/Resource.cpp
buildResources()函数中创建资源表相关的代码:
- status_t buildResources(Bundle* bundle, const sp
& assets, sp& builder) - {
- ...
- //设置资源类型
- ResourceTable::PackageType packageType = ResourceTable::App;
- if (bundle->getBuildSharedLibrary()) {
- packageType = ResourceTable::SharedLibrary;
- } else if (bundle->getExtending()) {
- packageType = ResourceTable::System;
- } else if (!bundle->getFeatureOfPackage().isEmpty()) {
- packageType = ResourceTable::AppFeature;
- }
- //创建资源表
- ResourceTable table(bundle, String16(assets->getPackage()), packageType);
- ...
- }
继续查看ResourceTable.cpp的构造函数。
ResourceTable.cpp位置:android-6.0.0_r1/frameworks/base/tools/aapt/ResourceTable.cpp
ResourceTable构造函数
- ResourceTable::ResourceTable(Bundle* bundle, const String16& assetsPackage, ResourceTable::PackageType type)
- : mAssetsPackage(assetsPackage)
- , mPackageType(type)
- , mTypeIdOffset(0)
- , mNumLocal(0)
- , mBundle(bundle)
- {
- ssize_t packageId = -1;
- switch (mPackageType) {
- case App:
- case AppFeature:
- packageId = 0x7f;
- break;
-
- case System:
- packageId = 0x01;
- break;
-
- case SharedLibrary:
- packageId = 0x00;
- break;
-
- default:
- assert(0);
- break;
- }
-
-
- sp
package = new Package(mAssetsPackage, packageId); - mPackages.add(assetsPackage, package);
- mOrderedPackages.add(package);
-
- // Every resource table always has one first entry, the bag attributes.
- const SourcePos unknown(String8("????"), 0);
- getType(mAssetsPackage, String16("attr"), unknown);
- }
应用的资源id从0x7f开始,系统的资源id从0x01开始,共享类库的从0x00开始。如果我们想要自定义应用的资源id的起始值,则需要在switch结束后重新设置packageId值。这个自定义值可以Main.cpp的main函数中解析获取,并存放到bundle中。
1,修改Bundle.h文件。
Bundle.h位置:android-6.0.0_r1/frameworks/base/tools/aapt/Bundle.h
添加如下代码:
- class Bundle {
- public:
- ...
- //添加的获取和设置自定义id的函数
- const android::String8& getApkModule() const {return mApkModule;}
- void setApkModule(const char* str) { mApkModule=str;}
- ...
-
- private:
- /* commands & modifiers */
- ...
- //自定义id
- android::String8 mApkModule;
- ...
- }
2,修改Main.cpp的main函数,添加解析自定义id的参数并设置到bundle。
代码如下:
- int main(int argc, char* const argv[])
- {
- ...
- while (argc && argv[0][0] == '-') {
- ...
- while (*cp != '\0') {
- ...
- case '-':
- ...
- //添加解析-apk-module参数信息
- } else if(strcmp(cp, "-apk-module") == 0){
- argc--;
- argv++;
- if (!argc) {
- fprintf(stderr, "ERROR: No argument supplied for '--apk-model' option\n");
- wantUsage = true;
- goto bail;
- }
- bundle.setApkModule(argv[0]);
- } else if (strcmp(cp, "-feature-of") == 0) {
- ...
- break;
- ...
- }
- ...
- }
- ...
- }
3,修改ResourceTable.cpp的构造函数,添加判断是否存在自定义id,如果存在,则修改packageId为自定义id。
- ResourceTable::ResourceTable(Bundle* bundle, const String16& assetsPackage, ResourceTable::PackageType type)
- ...
- {
- ssize_t packageId = -1;
- switch (mPackageType) {
- ...
- }
-
- //判断和设置自定义id
- if(!bundle->getApkModule().isEmpty()){
- android::String8 apkModuleVal = bundle->getApkModule();
- packageId = apkStringToInt(apkModuleVal);
- }
-
- sp
package = new Package(mAssetsPackage, packageId); - ...
- }
-
- //将字符串转换为ssize_t类型
- ssize_t ResourceTable::apkStringToInt(const String8& s){
- size_t i = 0;
- ssize_t val = 0;
- size_t len=s.length();
- if (s[i] < '0' || s[i] > '9') {
- return -1;
- }
-
- // Decimal or hex?
- if (s[i] == '0' && s[i+1] == 'x') {
- i += 2;
- bool error = false;
- while (i < len && !error) {
- val = (val*16) + apkgetHex(s[i], &error);
- i++;
- }
- if (error) {
- return -1;
- }
- } else {
- while (i < len) {
- if (s[i] < '0' || s[i] > '9') {
- return false;
- }
- val = (val*10) + s[i]-'0';
- i++;
- }
- }
-
- if (i == len) {
- return val;
- }
- return -1;
- }
- //转换为16进制
- uint32_t ResourceTable::apkgetHex(char c, bool* outError){
- if (c >= '0' && c <= '9') {
- return c - '0';
- } else if (c >= 'a' && c <= 'f') {
- return c - 'a' + 0xa;
- } else if (c >= 'A' && c <= 'F') {
- return c - 'A' + 0xa;
- }
- *outError = true;
- return 0;
- }
还需要在ResourceTable.h文件中声明apkStringToInt()和apkgetHex()函数。
ResourceTable.h位置:android-6.0.0_r1/frameworks/base/tools/aapt/ResourceTable.h
添加到public或private中。
- ssize_t apkStringToInt(const String8& s);
- uint32_t apkgetHex(char c, bool* outError);
修改完毕,开启终端(或控制台)进入到android-6.0.0_r1目录,运行. build/envsetup.sh命令,配置运行环境。配置命令运行完毕,运行cd frameworks/base/tools/aapt,进入到aapt目录。执行mm命令,该命令会编译aapt模块中的代码,并生成可执行文件。运行结果如下:
- ============================================
- PLATFORM_VERSION_CODENAME=REL
- PLATFORM_VERSION=6.0
- TARGET_PRODUCT=full
- TARGET_BUILD_VARIANT=eng
- TARGET_BUILD_TYPE=release
- TARGET_BUILD_APPS=
- TARGET_ARCH=arm
- TARGET_ARCH_VARIANT=armv7-a
- TARGET_CPU_VARIANT=generic
- TARGET_2ND_ARCH=
- TARGET_2ND_ARCH_VARIANT=
- TARGET_2ND_CPU_VARIANT=
- HOST_ARCH=x86_64
- HOST_OS=darwin
- HOST_OS_EXTRA=Darwin-16.0.0-x86_64-i386-64bit
- HOST_BUILD_TYPE=release
- BUILD_ID=MRA58K
- OUT_DIR=out
- ============================================
- host C++: aapt <= frameworks/base/tools/aapt/Main.cpp
- host Executable: aapt (out/host/darwin-x86/obj/EXECUTABLES/aapt_intermediates/aapt)
- clang: warning: argument unused during compilation: '-pie'
- Install: out/host/darwin-x86/bin/aapt
-
- \e[0;32m#### make completed successfully (3 seconds) ####\e[00m
生产的文件为aapt,在’android-6.0.0_r1/out/host/darwin-x86/bin/’目录中。
将aapt拷贝到指定目录,进入PluginDemo工程目录,使用aapt对工程进行资源打包,执行的命令如下:
- ../../../devTools/aapt/aapt package -f -m --apk-module 0x8f -J gen -S res -M AndroidManifest.xml -I ../../../devTools/android/android-sdk-macosx/platforms/android-23
- /android.jar -F build/out/res.ap_
该命令执行失败,某个资源id找不到对应的资源。错误信息:
res/layout/xxx.xml:9: error: Error: No resource found that matches the given name (at 'text' with value '@string/xxx').
搜索相关的博客,在区长的专栏的Android aapt实现资源分区(补充携程aapt源码)这篇博客找到了出错的原因和解决方法。
继续看代码,
- bool ResTable::stringToValue(Res_value* outValue, String16* outString,
- const char16_t* s, size_t len,
- bool preserveSpaces, bool coerceType,
- uint32_t attrID,
- const String16* defType,
- const String16* defPackage,
- Accessor* accessor,
- void* accessorCookie,
- uint32_t attrType,
- bool enforcePrivate) const
- {
- ...
- if (*s == '@') {
- if (accessor) {
- uint32_t rid = accessor->getCustomResourceWithCreation(package, type, name,
- createIfNotFound);
- if (rid != 0) {
- if (kDebugTableNoisy) {
- ALOGI("Pckg %s:%s/%s: 0x%08x\n",
- String8(package).string(), String8(type).string(),
- String8(name).string(), rid);
- }
- uint32_t packageId = Res_GETPACKAGE(rid) + 1;
- if (packageId == 0x00) {
- outValue->data = rid;
- outValue->dataType = Res_value::TYPE_DYNAMIC_REFERENCE;
- return true;
- } else if (packageId == APP_PACKAGE_ID || packageId == SYS_PACKAGE_ID ) {
- // We accept packageId's generated as 0x01 in order to support
- // building the android system resources
- outValue->data = rid;
- return true;
- }
- }
- }
- }
-
- if (accessor != NULL) {
- accessor->reportError(accessorCookie, "No resource found that matches the given name");
- }
- return false;
- }
- ...
- }
在if(accessor)代码中对packageId进行验证。如果packageId不是ResourceTable构造函数中设置的3种类型,则出错,无法生成R.java文件和资源包。需要将ResourceTable构造函数中设置的packageId值存储下来,并在if (packageId == APP_PACKAGE_ID || packageId == SYS_PACKAGE_ID )添加一个自定义id判断。
按照区长的博客添加头文件和cpp文件,并添加相应的代码。具体的代码请查看Android aapt实现资源分区(补充携程aapt源码)博客,本文不再写出。
1,创建文件
创建Help.h文件,存放在android-6.0.0_r1/frameworks/base/include/androidfw/。
创建Help.cpp文件,存放在android-6.0.0_r1/frameworks/base/libs/androidfw/。并将Help.cpp添加到android-6.0.0_r1/frameworks/base/libs/androidfw/Android.mk文件。
2,修改代码
在ResourceTable::ResourceTable()函数判断和设置自定义id代码后面添加使用Help记录packageId代码。
在ResTable::stringToValue()函数中添加对Help中记录的packageId判断代码。
重新编译aapt模块,获取新生成的aapt可执行文件。再次运行生成R.java和资源打包命令(与之前的命令相同),成功运行。
生成的R.java文件内容
- package com.plugin.test;
-
- public final class R {
- public static final class attr {
- }
- public static final class drawable {
- public static final int p_icon_play=0x8f020000;
- }
- public static final class id {
- public static final int activity_main=0x8f070000;
- }
- public static final class layout {
- public static final int plugin_item=0x8f040000;
- }
- public static final class mipmap {
- public static final int p_icon_lock=0x8f030000;
- }
- public static final class string {
- public static final int app_name=0x8f050000;
- public static final int p_str=0x8f050001;
- }
- public static final class style {
-
- public static final int AppBaseTheme=0x8f060000;
-
- public static final int AppTheme=0x8f060001;
- }
- }
不再是原来系统默认的0x7f,都是自定义的0x8f。
继续执行命令编译代码,将class转换为dex,并将dex和资源包合并生成的apk。对apk签名,运行apk。apk正常运行