facebook开发者网站上的官方文件:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Add code to print out the key hash
    try {
        PackageInfo info = getPackageManager().getPackageInfo(
                "com.facebook.samples.hellofacebook", 
                PackageManager.GET_SIGNATURES);
        for (Signature signature : info.signatures) {
            MessageDigest md = MessageDigest.getInstance("SHA");
            md.update(signature.toByteArray());
            Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
    } catch (NameNotFoundException e) {

    } catch (NoSuchAlgorithmException e) {

    }

下载openSSL for windows，你可以在这里找到64位和32位的 解压缩下载的文件 在C盘中创建文件夹名为openSSL 将所有提取的项目复制到openSSL文件夹(bin,include,lib, openSSL .cnf) 获取android调试密钥库，默认位置为

C:\Users\username\.android\ debug.keystore

现在获得命令提示符并粘贴这段代码

keytool -exportcert -alias androiddebugkey -keystore C：\Users\username.android\debug.keystore |“C：\openSSL\bin\openssl” sha1 -binary |“C：\openSSL\bin\openssl” base64

按enter键，你会得到28位的键码

[EDIT 2020]->现在我完全推荐这里的答案，使用android studio更容易，更快，不需要写任何代码-下面这个是在eclipse时代的:)-。

您可以在任何活动中使用此代码。它将在logcat中记录hashkey，这是调试键。这很简单，而且比使用SSL轻松。

PackageInfo info;
try {
    info = getPackageManager().getPackageInfo("com.you.name", PackageManager.GET_SIGNATURES);
    for (Signature signature : info.signatures) {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA");
        md.update(signature.toByteArray());
        String something = new String(Base64.encode(md.digest(), 0));
        //String something = new String(Base64.encodeBytes(md.digest()));
        Log.e("hash key", something);
    }
} catch (NameNotFoundException e1) {
    Log.e("name not found", e1.toString());
} catch (NoSuchAlgorithmException e) {
    Log.e("no such an algorithm", e.toString());
} catch (Exception e) {
    Log.e("exception", e.toString());
}

你可以在知道密钥后删除代码;)

这是Facebook官方页面上给出的内容:

   keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

让我把这个命令分解成几个片段。

Look for "keytool.exe". You can search that on the C: drive. You can find it in "java jdk" or "java jre". If you have installed multiple versions, choose any. Open a CMD prompt and go to the above directory where you found "keytool.exe". Clip the "exe`" and paste the above command provided on the Facebook page. You will get an error on entering this that OpenSSL is not recognized as in input output command. Solution : Download "Openssl" from OpenSSL (if you have a 64-bit machine you must download openssl-0.9.8e X64). Extract and save it anywhere... I saved it on the C: drive in the OpenSSl folder Replace the openssl in the above command in which you was getting an error of OpenSSL with "C:\OpenSSL\bin\openssl" at both the places after the pipe, "|". If prompted for a password, enter android.

你会得到你的哈希键。要了解进一步的步骤，请再次参考Facebook页面。

目前Facebook Android教程中的说明在Windows下并不适用。他们的例子展示了如何将keytool输出输出到openssl，但是如果你在Windows下尝试这样做，由于某些原因输出是无效的。我发现我必须使用中间文件才能让它正常工作。以下是对我有用的步骤:

首先从谷歌下载openssl for Windows。

C:\Users\Me>keytool -exportcert -alias my_key -keystore my.keystore -storepass PASSWORD > mycert.bin

C:\Users\Me>openssl sha1 -binary mycert.bin > sha1.bin

C:\Users\Me>openssl base64 -in sha1.bin -out base64.txt

运行这些命令后，有效的散列存储在文件base64.txt中。复制粘贴到你的Facebook应用设置中。

下载openSSL ->安装它->通常会安装在C:\ openSSL

然后打开CMD并键入

cd../../Program Files (Enter)

java (Enter)

dir (Enter)

cd jdk1.6.0_17 (varies with jdk versions) (Enter)

查看jdk版本到C:/program files/java/jdk_version

cd bin (enter)

keytool -exportcert -alias androiddebugkey -keystore C:Users\Shalini\.android\debug.keystore | "C:\OpenSSL\bin\openssl sha1 -binary | "C:\OpenSSL\bin\openssl base64 (Enter)

它会问你密码是android。