[譯] Android 的 Java 8 支持

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Source Transformation（源碼模擬實現）","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了更好的理解脫糖是如何工作的，我們可以在源碼的層面模擬實現，注意這裏的模擬僅僅是爲了加深理解，脫糖實際工作比這個要複雜的多。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"java"},"content":[{"type":"text","text":"class Java8 {\n interface Logger {\n void log(String s);\n }\n\n public static void main(String... args) {\n sayHi(s -> System.out.println(s));\n }\n\n private static void sayHi(Logger logger) {\n logger.log(\"Hello!\");\n }\n}\n","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"第一步","attrs":{}},{"type":"text","text":"將 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Native Lambdas","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在上面我們通過 ","attrs":{}},{"type":"codeinline","content":[{"type":"text","text":"dx","attrs":{}}],"attrs":{}},{"type":"text","text":" 工具編譯 ","attrs":{}},{"type":"codeinline","content":[{"type":"text","text":"dex","attrs":{}}],"attrs":{}},{"type":"text","text":" 文件時，錯誤信息提示我們最低的支持版本是 API 26。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"bash"},"content":[{"type":"text","text":"$ $ANDROID_HOME/build-tools/28.0.2/dx --dex --output . *.class\nUncaught translation error: com.android.dx.cf.code.SimException:\n ERROR in Java8.main:([Ljava/lang/String;)V:\n invalid opcode ba - invokedynamic requires --min-sdk-version >= 26\n (currently 13)\n1 error; 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","attrs":{}},{"type":"codeinline","content":[{"type":"text","text":"lambda","attrs":{}}],"attrs":{}},{"type":"text","text":" 表達式生成匿名類，而 ","attrs":{}},{"type":"codeinline","content":[{"type":"text","text":"D8","attrs":{}}],"attrs":{}},{"type":"text","text":" 是在編譯時生成。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如果我們查看 ","attrs":{}},{"type":"link","attrs":{"href":"https://developer.android.com/reference/java/lang/invoke/package-summary","title":"","type":null},"content":[{"type":"text","text":"Android documentation for java.lang.invoke ","attrs":{}}]},{"type":"text","text":" 和 ","attrs":{}},{"type":"link","attrs":{"href":"https://android.googlesource.com/platform/libcore/+/master/ojluni/src/main/java/java/lang/invoke/","title":"","type":null},"content":[{"type":"text","text":"AOSP source code for 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