このコードを試してください。すべての単語の最初の文字が大文字になります。
-EditTextビューにaddTextChangedListenerを設定します
edt_text.addTextChangedListener(watcher);
-TextWatcherを追加 
TextWatcher watcher = new TextWatcher() {
    int mStart = 0;
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        mStart = start + count;
    }
    @Override
    public void afterTextChanged(Editable s) {
        String input = s.toString();
        String capitalizedText;
        if (input.length() < 1)
            capitalizedText = input;
        else if (input.length() > 1 && input.contains(" ")) {
            String fstr = input.substring(0, input.lastIndexOf(" ") + 1);
            if (fstr.length() == input.length()) {
                capitalizedText = fstr;
            } else {
                String sstr = input.substring(input.lastIndexOf(" ") + 1);
                sstr = sstr.substring(0, 1).toUpperCase() + sstr.substring(1);
                capitalizedText = fstr + sstr;
            }
        } else
            capitalizedText = input.substring(0, 1).toUpperCase() + input.substring(1);
        if (!capitalizedText.equals(edt_text.getText().toString())) {
            edt_text.addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                }
                @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                }
                @Override
                public void afterTextChanged(Editable s) {
                    edt_text.setSelection(mStart);
                    edt_text.removeTextChangedListener(this);
                }
            });
            edt_text.setText(capitalizedText);
        }
    }
};