Android 如何判断CPU是32位还是64位

发布网友 发布时间：2022-04-20 09:22

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热心网友 时间：2022-06-20 20:15

可以利用三种方式来判断CPU是32位还是64位：1. 读取Android 的system property ("ro.proct.cpu.abilist64")来判断2. 读取"/proc/cpuinfo"文件的第一行来判断3. 读取libc.so文件的ELF头部e_indent[]数组，根据数组第e_indent[4]的取值来判断[java] view plain copy public static final String CPU_ARCHITECTURE_TYPE_32 = "32"; public static final String CPU_ARCHITECTURE_TYPE_64 = "64"; /** ELF文件头 e_indent[]数组文件类标识索引 */ private static final int EI_CLASS = 4; /** ELF文件头 e_indent[EI_CLASS]的取值：ELFCLASS32表示32位目标 */ private static final int ELFCLASS32 = 1; /** ELF文件头 e_indent[EI_CLASS]的取值：ELFCLASS64表示64位目标 */ private static final int ELFCLASS64 = 2; /** The system property key of CPU arch type */ private static final String CPU_ARCHITECTURE_KEY_64 = "ro.proct.cpu.abilist64"; /** The system libc.so file path */ private static final String SYSTEM_LIB_C_PATH = "/system/lib/libc.so"; private static final String SYSTEM_LIB_C_PATH_64 = "/system/lib64/libc.so"; private static final String PROC_CPU_INFO_PATH = "/proc/cpuinfo"; private static boolean LOGENABLE = false; /** * Check if the CPU architecture is x86 */ public static boolean checkIfCPUx86() { //1. Check CPU architecture: arm or x86 if (getSystemProperty("ro.proct.cpu.abi", "arm").contains("x86")) { //The CPU is x86 return true; } else { return false; } } /** * Get the CPU arch type: x32 or x64 */ public static String getArchType(Context context) { if (getSystemProperty(CPU_ARCHITECTURE_KEY_64, "").length() > 0) { if (LOGENABLE) { Log.d("###############getSystemProperty","CPU arch is 64bit"); } return CPU_ARCHITECTURE_TYPE_64; } else if (isCPUInfo64()) { return CPU_ARCHITECTURE_TYPE_64; } else if (isLibc64()) { return CPU_ARCHITECTURE_TYPE_64; } else { if (LOGENABLE) { Log.d("###############getArchType()","return cpu DEFAULT 32bit!"); } return CPU_ARCHITECTURE_TYPE_32; } } private static String getSystemProperty(String key, String defaultValue) { String value = defaultValue; try { Class<?> clazz= Class.forName("android.os.SystemProperties"); Method get = clazz.getMethod("get", String.class, String.class); value = (String)(get.invoke(clazz, key, "")); } catch (Exception e) { if (LOGENABLE) { Log.d("getSystemProperty", "key = " + key + ", error = " + e.getMessage()); } } if (LOGENABLE) { Log.d("getSystemProperty", key + " = " + value); } return value; } /** * Read the first line of "/proc/cpuinfo" file, and check if it is 64 bit. */ private static boolean isCPUInfo64() { File cpuInfo = new File(PROC_CPU_INFO_PATH); if (cpuInfo != null && cpuInfo.exists()) { InputStream inputStream = null; BufferedReader bufferedReader = null; try { inputStream = new FileInputStream(cpuInfo); bufferedReader = new BufferedReader(new InputStreamReader(inputStream), 512); String line = bufferedReader.readLine(); if (line != null && line.length() > 0 && line.toLowerCase(Locale.US).contains("arch64")) { if (LOGENABLE) { Log.d("###############isCPUInfo64()", PROC_CPU_INFO_PATH + " contains is arch64"); } return true; } else { if (LOGENABLE) { Log.d("###############isCPUInfo64()", PROC_CPU_INFO_PATH + " is not arch64"); } } } catch (Throwable t) { if (LOGENABLE) { Log.d("###############isCPUInfo64()","read " + PROC_CPU_INFO_PATH + " error = " + t.toString()); } } finally { try { if (bufferedReader != null) { bufferedReader.close(); } } catch (Exception e) { e.printStackTrace(); } try { if (inputStream != null) { inputStream.close(); } } catch (Exception e) { e.printStackTrace(); } } } return false; } /** * Check if system libc.so is 32 bit or 64 bit */ private static boolean isLibc64() { File libcFile = new File(SYSTEM_LIB_C_PATH); if (libcFile != null && libcFile.exists()) { byte[] header = readELFHeadrIndentArray(libcFile); if (header != null && header[EI_CLASS] == ELFCLASS64) { if (LOGENABLE) { Log.d("###############isLibc64()", SYSTEM_LIB_C_PATH + " is 64bit"); } return true; } } File libcFile64 = new File(SYSTEM_LIB_C_PATH_64); if (libcFile64 != null && libcFile64.exists()) { byte[] header = readELFHeadrIndentArray(libcFile64); if (header != null && header[EI_CLASS] == ELFCLASS64) { if (LOGENABLE) { Log.d("###############isLibc64()", SYSTEM_LIB_C_PATH_64 + " is 64bit"); } return true; } } return false; } /** * ELF文件头格式是固定的:文件开始是一个16字节的byte数组e_indent[16] * e_indent[4]的值可以判断ELF是32位还是64位 */ private static byte[] readELFHeadrIndentArray(File libFile) { if (libFile != null && libFile.exists()) { FileInputStream inputStream = null; try { inputStream = new FileInputStream(libFile); if (inputStream != null) { byte[] tempBuffer = new byte[16]; int count = inputStream.read(tempBuffer, 0, 16); if (count == 16) { return tempBuffer; } else { if (LOGENABLE) { Log.e("readELFHeadrIndentArray", "Error: e_indent lenght should be 16, but actual is " + count); } } } } catch (Throwable t) { if (LOGENABLE) { Log.e("readELFHeadrIndentArray", "Error:" + t.toString()); } } finally { if (inputStream != null) { try { inputStream.close(); } catch (Exception e) { e.printStackTrace(); } } } } return null; }