![](/img/trans.png)
[英]Why does a Java Tensorflow session seem to reset state when a Python Tensorflow session does not?
[英]Why does the state of an object declared as final seem to be reset even when it's altered inside an anonymous function?
我使用“令牌”(聲明為final的ValueContainer類的實例)來保存從JSON請求接收的數據。 在匿名函數Response.Listener()中,我設置了令牌的值,並且它可以工作。
Log.d("myTag", "token value1:" + token.getValue());
該行顯示正確的值(非null)。 但是,當我再次檢查token.getValue()的值時(這次在匿名函數之外)
Log.d("myTag", "token value2:" + token.getValue());
我得到token.getValue()= null。 我不明白為什么令牌的值似乎重置為null。 我想念什么嗎?
完整代碼:
public class MainActivity extends AppCompatActivity {
class ValueContainer<T> {
private T value;
public ValueContainer() { }
public ValueContainer(T value) {
this.value = value;
}
public T getValue() {
return value;
}
public void setValue(T value) {
this.value = value;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final ValueContainer<String> token = new ValueContainer<String>();
String getTokenUrl = "http://www.someurl.com/?somekey=somevalue";
JsonObjectRequest getTokenRequest = new JsonObjectRequest(
Request.Method.GET, getTokenUrl, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
token.setValue(response.getString("token"));
Log.d("myTag", "token value1:" + token.getValue());
mainTextView.append("Response: JsonObjectRequest successful: get_token: " + token.getValue() + "\n");
} catch (JSONException e) {
mainTextView.append("Response: JSONException: getString():" + e);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
mainTextView.append("Response: JsonObjectRequest failed: " + error + "\n");
}
});
Log.d("myTag", "token value2:" + token.getValue());
}
您可以更改“最終”對象的“實際內容”,但不能更改其地址,如示例所示。
String stringTest = "test String";
StringBuffer normalTest = new StringBuffer(stringTest);
normalTest = normalTest.append(" end");
normalTest.delete(0, 5);
System.out.println(normalTest);
final StringBuffer finalTest = new StringBuffer(stringTest);
// finalTest = finalTest.append(" end"); // can't work;
finalTest.delete(0, 5);
System.out.println(finalTest);
您可以通過您的代碼進行測試
//token = new Token("...")// can't work
token.changeTheToken("...")// work ok
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.