Android Framewrok 添加系统默认依赖库

目录

前言

1.定制库的创建

2.修改编译工具代码并解决报错。

 3.其他模块引用库内变量进行测试

---

前言

在android framework开发中，OEM 一般会封装一些定制库文件，几乎在系统中所有定制的模块和应用中都会依赖这些库文件，所以在每个Android.mk或Android.bp等编译文件中都需要添加库依赖。这样就比较麻烦，而系统原生framework.jar却是不需要在每个编译文件中进行添加就可以默认依赖。所以可以参照系统framework的处理方式，在编译系统中进行修改来实现此功能。

此功能基于Android12实现。

1.定制库的创建

1.先创建一个自定义的库（我是自己随便创建了一个库，一般oem都是有自己定制库的）

2.然后随便写了一行代码

package com.hoowi.example;
public class MyExample {

    public static final int INT = 1;

}

3.编写Android.bp文件

java_library {
    name: "hoowi.example",
    installable: true,
    srcs: [
        "com/hoowi/example/MyExample.java",
    ],
}

2.修改编译工具代码并解决报错。

1.修改build/soong/java/config/config.go文件，

var (
	pctx = android.NewPackageContext("android/soong/java/config")

	LegacyCorePlatformBootclasspathLibraries = []string{"legacy.core.platform.api.stubs", "core-lambda-stubs"}
	LegacyCorePlatformSystemModules          = "legacy-core-platform-api-stubs-system-modules"
	StableCorePlatformBootclasspathLibraries = []string{"stable.core.platform.api.stubs", "core-lambda-stubs"}
	StableCorePlatformSystemModules          = "stable-core-platform-api-stubs-system-modules"
    //在这里添加自定义库文件 hoowi.example
	FrameworkLibraries                       = []string{"ext", "framework", "hoowi.example"}
	DefaultLambdaStubsLibrary                = "core-lambda-stubs"
	SdkLambdaStubsPath                       = "prebuilts/sdk/tools/core-lambda-stubs.jar"

	DefaultMakeJacocoExcludeFilter = []string{"org.junit.*", "org.jacoco.*", "org.mockito.*"}
	DefaultJacocoExcludeFilter     = []string{"org.junit.**", "org.jacoco.**", "org.mockito.**"}

	InstrumentFrameworkModules = []string{
		"framework",
		"framework-minus-apex",
		"telephony-common",
		"services",
		"android.car",
		"android.car7",
		"conscrypt",
		"core-icu4j",
		"core-oj",
		"core-libart",
		// TODO: Could this be all updatable bootclasspath jars?
		"updatable-media",
		"framework-mediaprovider",
		"framework-sdkextensions",
		"android.net.ipsec.ike",
        //在这里添加自定义库文件 hoowi.example
		"hoowi.example",
	}
)

2.编译会报depends on undefined module的错误

3.这个是因为在go编译系统中的测试代码中没有添加模块定义，

修改build/soong/java/testing.go

func gatherRequiredDepsForTest() string {
	var bp string

	extraModules := []string{
		"core-lambda-stubs",
		"ext",
		"android_stubs_current",
		"android_system_stubs_current",
		"android_test_stubs_current",
		"android_module_lib_stubs_current",
		"android_system_server_stubs_current",
		"core.current.stubs",
		"legacy.core.platform.api.stubs",
		"stable.core.platform.api.stubs",
		"kotlin-stdlib",
		"kotlin-stdlib-jdk7",
		"kotlin-stdlib-jdk8",
		"kotlin-annotations",
        //这里添加测试模块定义
		"hoowi.example",
	}

	for _, extra := range extraModules {
		bp += fmt.Sprintf(`
			java_library {
				name: "%s",
				srcs: ["a.java"],
				sdk_version: "none",
				system_modules: "stable-core-platform-api-stubs-system-modules",
				compile_dex: true,
			}
		`, extra)
	}

	//........省略若干行

	return bp
}

 4.再次编译又会报depends on itself的错。

5.这个时候要重新修改自定义模块的Android.bp文件加入一行 sdk_version: "core_platform",

java_library {
    name: "hoowi.example",
    installable: true,
    sdk_version: "core_platform",//就是这一行代码
    srcs: [
        "com/hoowi/example/MyExample.java",
    ],
}

 6.再次编译又报错

7.这个时候修改build/soong/java/java_test.go

func TestPatchModule(t *testing.T) {
	//......省略若干行

	t.Run("Java language level 9", func(t *testing.T) {
		// Test with default javac -source 9 -target 9
		bp := `
			java_library {
				name: "foo",
				srcs: ["a.java"],
			}

			java_library {
				name: "bar",
				srcs: ["b.java"],
				sdk_version: "none",
				system_modules: "none",
				patch_module: "java.base",
			}

			java_library {
				name: "baz",
				srcs: [
					"c.java",
					// Tests for b/150878007
					"dir/d.java",
					"dir2/e.java",
					"dir2/f.java",
					"nested/dir/g.java"
				],
				patch_module: "java.base",
			}
		`
		ctx, _ := testJava(t, bp)

		checkPatchModuleFlag(t, ctx, "foo", "")
		expected := "java.base=.:out/soong"
		checkPatchModuleFlag(t, ctx, "bar", expected)
        //在这里添加自定义库（需要注意的是这里的库的顺序要与config.go中添加自定义库的顺序一致，不然也会报错）
		expected = "java.base=" + strings.Join([]string{
			".", "out/soong", "dir", "dir2", "nested", defaultModuleToPath("ext"), defaultModuleToPath("framework"),
			 defaultModuleToPath("hoowi.example")}, ":")
		checkPatchModuleFlag(t, ctx, "baz", expected)
	})
}

8.nice，终于编译通过了。

 3.其他模块引用库内变量进行测试

随便找一个库或者app引用下，可以引用到，编译可以通过。

nice，到此功能就实现了。