how to remove title from actionbar

This is how to remove title from action bar using appcompat.



First, add the following lines to styles.xml in res/values folder.



<style name="AppTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
        <item name="actionBarStyle">@style/Widget.Styled.ActionBar</item>
        <item name="android:actionBarStyle">@style/Widget.Styled.ActionBar</item>
    </style>

    <style name="Widget.Styled.ActionBar" parent="Widget.AppCompat.Light.ActionBar.Solid.Inverse">
        <item name="android:displayOptions">showHome|useLogo</item>
        <item name="displayOptions">showHome|useLogo</item>
    </style>

</resources>




Then, change android:theme attribute of your activity in manifest file.

<activity
            android:name="MainActivity2"
            android:theme="@style/AppTheme" >



You should use same name like the blue text above.

invalid utf-8 start byte

change charset and(or) pageEncoding to UTF-8.



<%@ page language="java" contentType="application/json; charset=EUC-KR"
    pageEncoding="EUC-KR"%>


<%@ page language="java" contentType="application/json; charset=UTF-8"
    pageEncoding="UTF-8"%>

Could not extract response: no suitable HttpMessageConverter found

Check if content type of server side(for example, jsp file) is application/json(if it is json).



<%@ page language="java" contentType="application/json; charset=EUC-KR"

    pageEncoding="EUC-KR"%>





import can't be resolved in jsp

make package under src folder of Java Resources, and put java class file in the folder.

how to get 100% correct key hash for facebook auth

@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) {

    }




Put the above code in any class file of your app to get correct key hash. Change "com.facebook.samples.hellofacebook" to your package name. Check log to get key hash and put the hash in the setting of facebook app.  

Session: an attempt was made to request new permissions for a session that has a pending request

It can be key hash problem. make key hash with release key, and add the key at facebook apps setting with debug key hash. I guess debug key hash is not working.