在一个Android应用中因为要获取系统的属性, 比如说型号, model等一些属性, 通过下列方法就可以获取到.首先查看手机/system目录下build.prop文件。
在手机/system目录下build.prop文件存放手机相关系统属性。
build.prop是如何生成的呢？
Android的build.prop文件是在Android编译时刻收集的各种property。
编译完成之后，文件生成在/out/target/product/huaqin75_cu_ics/system/目录下。
在Android运行时刻可以通过SystemProperties_get*()读取这些属性值。
build.prop的生成是由make系统解析build/core/Makefile完成。
genymotion模拟器下面的build.prop相关属性。
# begin build properties
# autogenerated by buildinfo.sh
ro.build.id=JDQ39E
ro.build.display.id=vbox86p-userdebug 4.2.2 JDQ39E eng.buildbot.20151117.140513 test-keys
ro.build.version.incremental=eng.buildbot.20151117.140513
ro.build.version.sdk=17
ro.build.version.codename=REL
ro.build.version.release=4.2.2
ro.build.date=Tue Nov 17 14:07:43 CET 2015
ro.build.date.utc=1447765663
ro.build.type=userdebug
ro.build.user=buildbot
ro.build.host=buildbot.soft.genymobile.com
ro.build.tags=test-keys
ro.product.brand=generic
ro.product.name=vbox86p
ro.product.device=vbox86p
ro.product.board=
ro.product.cpu.abi=x86
ro.product.manufacturer=Genymotion
ro.product.locale.language=en
ro.product.locale.region=US
ro.wifi.channels=
ro.board.platform=
# ro.build.product is obsolete; use ro.product.device
ro.build.product=vbox86p
# Do not try to parse ro.build.description or .fingerprint
ro.build.description=vbox86p-userdebug 4.2.2 JDQ39E eng.buildbot.20151117.140513 test-keys
ro.build.fingerprint=generic/vbox86p/vbox86p:4.2.2/JDQ39E/eng.buildbot.20151117.140513:userdebug/test-keys
ro.build.characteristics=default
# end build properties
#
# system.prop for Genymotion
#
# Build informations
ro.product.name=Genymotion
ro.product.manufacturer=Genymobile
rild.libpath=/system/lib/libreference-ril.so
dalvik.vm.heapsize=256m
persist.service.adb.enable=1
ro.secure=0
ro.opengles.version=131072
ro.genymotion.version=2.6.0
# Add device version
ro.genymotion.device.version=1
#
# Capabilities
#
# Battery sensor
ro.genyd.caps.bat=on
# GPS sensor
ro.genyd.caps.gps=on
# Accelerometer sensor
ro.genyd.caps.acc=on
# Webcam / camera sensor
ro.genyd.caps.cam=on
# Screencast / screenshot capability
ro.genyd.caps.scr=on
# Remote controller capability
ro.genyd.caps.rmt=on
# DeviceID / IMEI and AndroidID emulation
ro.genyd.caps.did=on
# Network control capability
ro.genyd.caps.net=on
#
# ADDITIONAL_BUILD_PROPERTIES
#
keyguard.no_require_sim=true
ro.com.android.dataroaming=true
ro.com.android.dateformat=MM-dd-yyyy
ro.config.ringtone=Ring_Synth_04.ogg
ro.config.notification_sound=pixiedust.ogg
ro.carrier=unknown
ro.config.alarm_alert=Alarm_Classic.ogg
rild.libargs=-s/dev/socket/baseband_ril
ro.genyd.caps.baseband=on
ro.ril.hsxpa=1
ro.ril.gprsclass=10
wifi.interface=eth1
dalvik.vm.heapstartsize=8m
dalvik.vm.heapgrowthlimit=96m
dalvik.vm.heapsize=256m
dalvik.vm.heaptargetutilization=0.75
dalvik.vm.heapminfree=512k
dalvik.vm.heapmaxfree=8m
dalvik.vm.lockprof.threshold=500
net.bt.name=Android
dalvik.vm.stack-trace-file=/data/anr/traces.txt
主要通过adb命令shell命令查看此文件信息，导出build.prop文件：adb pull /system/build.prop d:/test 将文件复制到电脑D盘test目录下
通过Java反射机制获取SystemProperties.java内容，因为SystemProperties.java已被系统隐藏，通过get和set方法来读取build.prop里面的内容
在此我通过反射机制来读取系统属性：
import java.io.File;
import java.lang.reflect.Method;
import dalvik.system.DexFile;
import android.content.Context;
public class SystemPropertiesProxy {
/**
* 根据给定Key获取值.
*
* @return 如果不存在该key则返回空字符串
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
*/
public static String get(Context context, String key) throws IllegalArgumentException {
String ret = "";
try {
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[1];
paramTypes[0] = String.class;
Method get = SystemProperties.getMethod("get", paramTypes);
//参数
Object[] params = new Object[1];
params[0] = new String(key);
ret = (String) get.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
ret = "";
//TODO
}
return ret;
}
/**
* 根据Key获取值.
*
* @return 如果key不存在, 并且如果def不为空则返回def否则返回空字符串
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
*/
public static String get(Context context, String key, String def) throws IllegalArgumentException {
String ret = def;
try {
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[2];
paramTypes[0] = String.class;
paramTypes[1] = String.class;
Method get = SystemProperties.getMethod("get", paramTypes);
//参数
Object[] params = new Object[2];
params[0] = new String(key);
params[1] = new String(def);
ret = (String) get.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
ret = def;
//TODO
}
return ret;
}
/**
* 根据给定的key返回int类型值.
*
* @param key 要查询的key
* @param def 默认返回值
* @return 返回一个int类型的值, 如果没有发现则返回默认值
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
*/
public static Integer getInt(Context context, String key, int def) throws IllegalArgumentException {
Integer ret = def;
try {
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[2];
paramTypes[0] = String.class;
paramTypes[1] = int.class;
Method getInt = SystemProperties.getMethod("getInt", paramTypes);
//参数
Object[] params = new Object[2];
params[0] = new String(key);
params[1] = new Integer(def);
ret = (Integer) getInt.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
ret = def;
//TODO
}
return ret;
}
/**
* 根据给定的key返回long类型值.
*
* @param key 要查询的key
* @param def 默认返回值
* @return 返回一个long类型的值, 如果没有发现则返回默认值
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
*/
public static Long getLong(Context context, String key, long def) throws IllegalArgumentException {
Long ret = def;
try {
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[2];
paramTypes[0] = String.class;
paramTypes[1] = long.class;
Method getLong = SystemProperties.getMethod("getLong", paramTypes);
//参数
Object[] params = new Object[2];
params[0] = new String(key);
params[1] = new Long(def);
ret = (Long) getLong.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
ret = def;
//TODO
}
return ret;
}
/**
* 根据给定的key返回boolean类型值.
* 如果值为 'n', 'no', '0', 'false' or 'off' 返回false.
* 如果值为'y', 'yes', '1', 'true' or 'on' 返回true.
* 如果key不存在, 或者是其它的值, 则返回默认值.
*
* @param key 要查询的key
* @param def 默认返回值
* @return 返回一个boolean类型的值, 如果没有发现则返回默认值
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
*/
public static Boolean getBoolean(Context context, String key, boolean def) throws IllegalArgumentException {
Boolean ret = def;
try {
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = cl.loadClass("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[2];
paramTypes[0] = String.class;
paramTypes[1] = boolean.class;
Method getBoolean = SystemProperties.getMethod("getBoolean", paramTypes);
//参数
Object[] params = new Object[2];
params[0] = new String(key);
params[1] = new Boolean(def);
ret = (Boolean) getBoolean.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
ret = def;
//TODO
}
return ret;
}
/**
* 根据给定的key和值设置属性, 该方法需要特定的权限才能操作.
*
* @throws IllegalArgumentException 如果key超过32个字符则抛出该异常
* @throws IllegalArgumentException 如果value超过92个字符则抛出该异常
*/
public static void set(Context context, String key, String val) throws IllegalArgumentException {
try {
@SuppressWarnings("unused")
DexFile df = new DexFile(new File("/system/app/Settings.apk"));
@SuppressWarnings("unused")
ClassLoader cl = context.getClassLoader();
@SuppressWarnings("rawtypes")
Class SystemProperties = Class.forName("android.os.SystemProperties");
//参数类型
@SuppressWarnings("rawtypes")
Class[] paramTypes = new Class[2];
paramTypes[0] = String.class;
paramTypes[1] = String.class;
Method set = SystemProperties.getMethod("set", paramTypes);
//参数
Object[] params = new Object[2];
params[0] = new String(key);
params[1] = new String(val);
set.invoke(SystemProperties, params);
} catch (IllegalArgumentException iAE) {
throw iAE;
} catch (Exception e) {
//TODO
}
}
}
这样就可以去获取咯：
SystemPropertiesProxy.get(this, "ro.build.version.release")；
