Android開發工具類

public final class SystemTool {


/**
 * 指定格式返回當前系統時間
 */
public static String getDataTime(String format) {
    SimpleDateFormat df = new SimpleDateFormat(format);
    return df.format(new Date());
}

/**
 * 返回當前系統時間(格式以HH:mm形式)
 */
public static String getDataTime() {
    return getDataTime("HH:mm");
}

/**
 * 獲取手機IMEI碼
 */
public static String getPhoneIMEI(Context cxt) {
    TelephonyManager tm = (TelephonyManager) cxt.getSystemService(Context.TELEPHONY_SERVICE);
    return tm.getDeviceId();
}

/**
 * 獲取手機系統SDK版本
 *
 * @return 如API 17 則返回 17
 */
public static int getSDKVersion() {
    return android.os.Build.VERSION.SDK_INT;
}

/**
 * 獲取系統版本
 *
 * @return 形如2.3.3
 */
public static String getSystemVersion() {
    return android.os.Build.VERSION.RELEASE;
}

/**
 * 調用系統發送短信
 */
public static void sendSMS(Context cxt, String smsBody) {
    Uri smsToUri = Uri.parse("smsto:");
    Intent intent = new Intent(Intent.ACTION_SENDTO, smsToUri);
    intent.putExtra("sms_body", smsBody);
    cxt.startActivity(intent);
}

/**
 * 判斷網絡是否連接
 */
public static boolean checkNet(Context context) {
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo info = cm.getActiveNetworkInfo();
    return info != null;// 網絡是否連接
}

/**
 * 判斷是否為wifi聯網
 */
public static boolean isWiFi(Context cxt) {
    ConnectivityManager cm = (ConnectivityManager) cxt.getSystemService(Context.CONNECTIVITY_SERVICE);
    // wifi的狀態：ConnectivityManager.TYPE_WIFI
    // 3G的狀態：ConnectivityManager.TYPE_MOBILE
    State state = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();
    return State.CONNECTED == state;
}

/**
 * 隱藏系統鍵盤 <br>
 * <b>警告</b> 必須是確定鍵盤顯示時才能調用
 */
public static void hideKeyBoard(Activity aty) {
    ((InputMethodManager) aty.getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow(aty.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

/**
 * 判斷當前應用程序是否后臺運行
 */
public static boolean isBackground(Context context) {
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
        if (appProcess.processName.equals(context.getPackageName())) {
            if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
                // 后臺運行
                return true;
            } else {
                // 前臺運行
                return false;
            }
        }
    }
    return false;
}

/**
 * 判斷手機是否處理睡眠
 */
public static boolean isSleeping(Context context) {
    KeyguardManager kgMgr = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
    boolean isSleeping = kgMgr.inKeyguardRestrictedInputMode();
    return isSleeping;
}

/**
 * 安裝apk
 *
 * @param context
 * @param file
 */
public static void installApk(Context context, File file) {
    Intent intent = new Intent();
    intent.setAction("android.intent.action.VIEW");
    intent.addCategory("android.intent.category.DEFAULT");
    intent.setType("application/vnd.android.package-archive");
    intent.setData(Uri.fromFile(file));
    intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(intent);
}

/**
 * 獲取當前應用程序的版本號
 */
public static String getAppVersion(Context context) {
    String version = "0";
    try {
        version = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionName;
    } catch (PackageManager.NameNotFoundException e) {
        throw new KJException(SystemTool.class.getName() + "the application not found");
    }
    return version;
}

/**
 * 回到home，后臺運行
 */
public static void goHome(Context context) {
    Intent mHomeIntent = new Intent(Intent.ACTION_MAIN);
    mHomeIntent.addCategory(Intent.CATEGORY_HOME);
    mHomeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
    context.startActivity(mHomeIntent);
}

/**
 * 獲取應用簽名
 *
 * @param context
 * @param pkgName
 */
public static String getSign(Context context, String pkgName) {
    try {
        PackageInfo pis = context.getPackageManager().getPackageInfo(pkgName, PackageManager.GET_SIGNATURES);
        return hexdigest(pis.signatures[0].toByteArray());
    } catch (NameNotFoundException e) {
        throw new KJException(SystemTool.class.getName() + "the " + pkgName + "'s application not found");
    }
}

/**
 * 將簽名字符串轉換成需要的32位簽名
 */
private static String hexdigest(byte[] paramArrayOfByte) {
    final char[] hexDigits = { 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 97, 98, 99, 100, 101, 102 };
    try {
        MessageDigest localMessageDigest = MessageDigest.getInstance("MD5");
        localMessageDigest.update(paramArrayOfByte);
        byte[] arrayOfByte = localMessageDigest.digest();
        char[] arrayOfChar = new char[32];
        for (int i = 0, j = 0;; i++, j++) {
            if (i >= 16) { return new String(arrayOfChar); }
            int k = arrayOfByte[i];
            arrayOfChar[j] = hexDigits[(0xF & k >>> 4)];
            arrayOfChar[++j] = hexDigits[(k & 0xF)];
        }
    } catch (Exception e) {}
    return "";
}

/**
 * 獲取設備的可用內存大小
 *
 * @param cxt
 *            應用上下文對象context
 * @return 當前內存大小
 */
public static int getDeviceUsableMemory(Context cxt) {
    ActivityManager am = (ActivityManager) cxt.getSystemService(Context.ACTIVITY_SERVICE);
    MemoryInfo mi = new MemoryInfo();
    am.getMemoryInfo(mi);
    // 返回當前系統的可用內存
    return (int) (mi.availMem / (1024 * 1024));
}

/**
 * 清理后臺進程與服務
 *
 * @param cxt
 *            應用上下文對象context
 * @return 被清理的數量
 */
public static int gc(Context cxt) {
    long i = getDeviceUsableMemory(cxt);
    int count = 0; // 清理掉的進程數
    ActivityManager am = (ActivityManager) cxt.getSystemService(Context.ACTIVITY_SERVICE);
    // 獲取正在運行的service列表
    List<RunningServiceInfo> serviceList = am.getRunningServices(100);
    if (serviceList != null) for (RunningServiceInfo service : serviceList) {
        if (service.pid == android.os.Process.myPid()) continue;
        try {
            android.os.Process.killProcess(service.pid);
            count++;
        } catch (Exception e) {
            e.getStackTrace();
            continue;
        }
    }

    // 獲取正在運行的進程列表
    List<RunningAppProcessInfo> processList = am.getRunningAppProcesses();
    if (processList != null) for (RunningAppProcessInfo process : processList) {
        // 一般數值大于RunningAppProcessInfo.IMPORTANCE_SERVICE的進程都長時間沒用或者空進程了
        // 一般數值大于RunningAppProcessInfo.IMPORTANCE_VISIBLE的進程都是非可見進程，也就是在后臺運行著
        if (process.importance > RunningAppProcessInfo.IMPORTANCE_VISIBLE) {
            // pkgList 得到該進程下運行的包名
            String[] pkgList = process.pkgList;
            for (String pkgName : pkgList) {
                try {
                    am.killBackgroundProcesses(pkgName);
                    count++;
                } catch (Exception e) { // 防止意外發生
                    e.getStackTrace();
                    continue;
                }
            }
        }
    }
    //"清理了" + (getDeviceUsableMemory(cxt) - i) + "M內存";
    return count;
}

}</pre>