下载open ssl:

然后将openssl\bin添加到路径系统变量中:

我的电脑->属性->高级配置->高级->系统变量->系统变量下查找路径，并将此添加到其结尾: ; yourFullOpenSSLDir \ bin

现在在你的jdk\bin文件夹C:\Program Files\Java\ jdk1.8.0_40\bin上打开一个命令行(在windows上按住shift并右键单击->打开命令行此处)，并使用:

keytool -exportcert -alias keystorealias -keystore C:\yourkeystore\folder\keystore.jks | openssl sha1 -binary | openssl base64

并复制它在给出密码后生成的长度为28的数字。

你可以用这个apk

1.first install the app from the Google play store
2.install the above apk
3.launch the apk and input the package name of your app
4.then you will get the hash code you want

自从API 26以来，你可以在KOTLIN中使用以下代码生成你的HASH key，而不需要任何Facebook SDK。

fun generateSSHKey(context: Context){
    try {
        val info = context.packageManager.getPackageInfo(context.packageName, PackageManager.GET_SIGNATURES)
        for (signature in info.signatures) {
            val md = MessageDigest.getInstance("SHA")
            md.update(signature.toByteArray())
            val hashKey = String(Base64.getEncoder().encode(md.digest()))
            Log.i("AppLog", "key:$hashKey=")
        }
    } catch (e: Exception) {
        Log.e("AppLog", "error:", e)
    }

}

这就是我如何获得我的:

private class SessionStatusCallback implements Session.StatusCallback {
        @Override
        public void call(Session session, SessionState state, Exception exception) {

            if (exception != null) {
                new AlertDialog.Builder(FriendActivity.this)
                        .setTitle(R.string.login_failed_dialog_title)
                        .setMessage(exception.getMessage())
                        .setPositiveButton(R.string.ok_button, null)
                        .show();
            }

因此，当您试图在没有密钥的情况下输入时，将会出现异常。Facebook在这个例外中加入了RIGHT键。你所要做的就是复制它。

请试试这个:

public static void printHashKey(Context pContext) {
        try {
            PackageInfo info = pContext.getPackageManager().getPackageInfo(pContext.getPackageName(), PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                String hashKey = new String(Base64.encode(md.digest(), 0));
                Log.i(TAG, "printHashKey() Hash Key: " + hashKey);
            }
        } catch (NoSuchAlgorithmException e) {
            Log.e(TAG, "printHashKey()", e);
        } catch (Exception e) {
            Log.e(TAG, "printHashKey()", e);
        }
    }

你可以从https://console.developers.google.com/projectselector/apis/credentials上获得你所有的指纹 然后使用下面的Kotlin代码将其转换为keyhash:

fun main(args: Array<String>) {
    listOf("<your_production_sha1_fingerprint>",
            "<your_debug1_sha1_fingerprint>",
            "<your_debug2_sha1_fingerprint>")
            .map { it.split(":") }
            .map { it.map { it.toInt(16).toByte() }.toByteArray() }
            .map { String(Base64.getEncoder().encode(it)) }
            .forEach { println(it) }
}