java - 空点异常 - ImageLoader-6ren

java - 空点异常 - ImageLoader

转载作者：行者123 更新时间：2023-12-02 05:30:48

在尝试加载以下 Activity 时，我遇到了 NullPoint 异常，我尝试解决这些问题，但我的尝试没有成功。

简而言之，有两个 Activity - 一个 Activity 填充数组列表，单击数组列表中的某个项目后，用户将进入第二个 Activity 页面(此页面)，该页面填充有关该项目的更多信息。我的问题已在第二个 Activity 中通过 JSON 填充图像时得到解决。

下面是 logcat 消息:

08-28 23:35:21.478: E/AndroidRuntime(5085): FATAL EXCEPTION: main
08-28 23:35:21.478: E/AndroidRuntime(5085): Process: com.dooba.beta, PID: 5085
08-28 23:35:21.478: E/AndroidRuntime(5085): java.lang.NullPointerException
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:233)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.volley.toolbox.ImageLoader.get(ImageLoader.java:171)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.volley.toolbox.NetworkImageView.loadImageIfNecessary(NetworkImageView.java:140)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.volley.toolbox.NetworkImageView.onLayout(NetworkImageView.java:180)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1660)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1436)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.HorizontalScrollView.onLayout(HorizontalScrollView.java:1474)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1055)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.View.layout(View.java:14817)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewGroup.layout(ViewGroup.java:4631)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1987)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1744)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.Choreographer.doCallbacks(Choreographer.java:574)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.Choreographer.doFrame(Choreographer.java:544)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.os.Handler.handleCallback(Handler.java:733)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.os.Handler.dispatchMessage(Handler.java:95)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.os.Looper.loop(Looper.java:136)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at android.app.ActivityThread.main(ActivityThread.java:5017)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at java.lang.reflect.Method.invokeNative(Native Method)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at java.lang.reflect.Method.invoke(Method.java:515)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-28 23:35:21.478: E/AndroidRuntime(5085):     at dalvik.system.NativeStart.main(Native Method)

第一个 Activity 代码

public class CasualEventsActivity extends Activity {

    private static final String URL_WEB_SERVICE = "http://dooba.ca/analytics/casual.php";
    private GridView gv;
    private ArrayList<Events_List> container;
    private ArrayList<Events_List> items;
    public Uri list_item_bac;
    public String list_item_name;
    public String list_item_description;
    public String list_item_location;
    public String single_list_item_description;
    public String list_item_price;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.events_list_layout);
        gv = (GridView) findViewById(R.id.gridview);
        container = new ArrayList<Events_List>();
        //download JSON
        listDownload();


        GridView s = (GridView) findViewById(R.id.gridview);
        s.setOnItemClickListener(new OnItemClickListener(){

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent = new Intent(CasualEventsActivity.this,CasualEventsSingleItemActivity.class);

                intent.putExtra("list_item_name", container.get(position).getList_item_title());
                intent.putExtra("list_item_location", container.get(position).getList_item_location());
                intent.putExtra("single_list_item_description", container.get(position).getSingle_list_item_description());
                startActivity(intent); //start Activity
            }
        });
    }
    public void listDownload(){
        RequestQueue volley = Volley.newRequestQueue(this);
        JsonObjectRequest json = new JsonObjectRequest(Method.GET, URL_WEB_SERVICE, null, ResponseListener(), ErrorListener());
        volley.add(json);
    }

    private Response.Listener<JSONObject> ResponseListener() {
        return new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    //your JSON Array
                    JSONArray array = response.getJSONArray("list_item");
                    for(int i = 0; i < array.length(); i++){
                        container.add(convertirAnuncio(array.getJSONObject(i)));
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                gv.setAdapter(new AdapterEvents(getApplicationContext(),container));
                }
            };
        };


    private Response.ErrorListener ErrorListener() {
        return new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) { }
        };
    }

    //object JSON
    private final Events_List convertirAnuncio(JSONObject obj) throws JSONException {
        long id = obj.getLong("id"); //id 
        String list_item_name = obj.getString("list_item_name"); 
        String list_item_location = obj.getString("list_item_location"); 
        String list_item_description = obj.getString("list_item_description");
        String single_list_item_description = obj.getString("single_list_item_description");
        Uri uri = Uri.parse(obj.getString("list_item_bac"));
        return new Events_List(id, list_item_location, single_list_item_description,list_item_name,list_item_description,list_item_price, uri);
    }
}

第二个 Activity 代码

public class CasualEventsSingleItemActivity extends Activity {

    // Declare Variables
    String list_item_name;
    String list_item_description;
    String list_item_price;
    String list_item_location;

    String single_list_item_description;




    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_events_single_item);


        RequestQueue mRequestQueue = null;
        ImageLoader mImageLoader = new ImageLoader(mRequestQueue,
                new ImageLoader.ImageCache() {
            private final LruCache<String, Bitmap>
                    cache = new LruCache<String, Bitmap>(20);

            @Override
            public Bitmap getBitmap(String url) {
                return cache.get(url);
            }

            @Override
            public void putBitmap(String url, Bitmap bitmap) {
                cache.put(url, bitmap);
            }
        });


        Intent i = getIntent();
        list_item_name = i.getStringExtra("list_item_name");
        list_item_location = i.getStringExtra("list_item_location");



        single_list_item_description = i.getStringExtra("single_list_item_description");

        TextView txtname = (TextView) findViewById(R.id.name);
        TextView txtlocation = (TextView) findViewById(R.id.location);
        TextView txtsdescription = (TextView) findViewById(R.id.sdescription);


        NetworkImageView hsvimage1 = (NetworkImageView) findViewById(R.id.hsvimage1);
        NetworkImageView hsvimage2 = (NetworkImageView) findViewById(R.id.hsvimage2);
        NetworkImageView hsvimage3 = (NetworkImageView) findViewById(R.id.hsvimage3);

        // Get image URLs from your previous network request...
        // I could not determine where this is stored from code in your question.
        String url1 = "I would want to populate the list_bac JSON string that links to a image URL";   // e.g. http://example.com/images/image1.png
        String url2 = "I would want to populate the list_bac JSON string that links to a image URL";
        String url3 = "I would want to populate the list_bac JSON string that links to a image URL";

        // Set the URL of the image that should be loaded into this view, and
        // specify the ImageLoader that will be used to make the request.
        hsvimage1.setImageUrl(url1, mImageLoader);
        hsvimage2.setImageUrl(url2, mImageLoader);
        hsvimage3.setImageUrl(url3, mImageLoader);


        // Set results to the TextViews
        txtname.setText(list_item_name);
        txtlocation.setText(list_item_location);
        txtsdescription.setText(single_list_item_description);


        Button mConfirm2 = (Button)findViewById(R.id.bConfirm2);
        mConfirm2.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                ParseUser currentUser = ParseUser.getCurrentUser();

               // Create the class and the columns
                currentUser.saveInBackground();

                currentUser.put("ActivityName", list_item_name); 
                currentUser.saveInBackground(new SaveCallback() {
                    @Override
                    public void done(ParseException e) {
                        setProgressBarIndeterminateVisibility(false);

                        if (e == null) {
                            // Success!
                            Intent intent = new Intent(CasualEventsSingleItemActivity.this, usermatch.class);
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                            startActivity(intent);
                        }
                        else {
                            AlertDialog.Builder builder = new AlertDialog.Builder(CasualEventsSingleItemActivity.this);
                            builder.setMessage(e.getMessage())
                                .setTitle(R.string.signup_error_title)
                                .setPositiveButton(android.R.string.ok, null);
                            AlertDialog dialog = builder.create();
                            dialog.show();
                        }
                   }
               });
                //CasualEventsSingleItemActivity.this.startActivity(new Intent(CasualEventsSingleItemActivity.this, MatchingActivity.class));
            }
        });









    }

第二个 Activity 布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
        android:background="@drawable/blue_bac3"
    android:gravity="center"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="15dp"
         android:layout_marginTop="10dp"

        android:layout_marginRight="15dp"
        android:alpha="0.9"
        android:paddingBottom="3dp"
        android:shadowColor="#000000"
        android:shadowDx="3"
        android:shadowDy="3"
        android:shadowRadius="0.01"
        android:textColor="#82CAFF"
        android:textSize="24sp" />

    <TextView
        android:id="@+id/location"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/name"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="15dp"
        android:layout_marginRight="15dp"
        android:alpha="0.8"
        android:paddingBottom="5dp"
        android:shadowColor="#000000"
        android:shadowDx="3"
        android:shadowDy="3"
        android:shadowRadius="0.01"
        android:textAlignment="center"
        android:textColor="#f2f2f2"
        android:textSize="16sp" />

    <ImageView
        android:id="@+id/dividertop"
        android:layout_width="370dp"
        android:layout_centerHorizontal="true"
        android:layout_height="wrap_content"
        android:layout_below="@+id/location"
        android:alpha="0.6"
        android:background="@drawable/divider11"
        android:paddingBottom="3dp" />

    <ImageView
        android:id="@+id/dividerbottom"
        android:layout_width="370dp"
                android:layout_centerHorizontal="true"

        android:layout_height="wrap_content"
        android:layout_below="@+id/vsvdescription"
       android:alpha="0.6"
        android:background="@drawable/divider11"
        android:paddingBottom="3dp" />

    <ImageView
        android:id="@+id/image_head"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:background="#000000"
        android:padding="1dp" />

    <HorizontalScrollView
        android:id="@+id/isgallery"
        android:layout_width="370dp"
        android:layout_height="90dp"
        android:layout_centerHorizontal="true"
        android:layout_below="@+id/dividerbottom"
        android:layout_marginTop="8dp"
         >

            <LinearLayout
                android:orientation="horizontal"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" >

               <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/hsvimage1"
                android:layout_width="148dp"
                android:layout_height="90dp"
                android:layout_marginRight="6dp"
                android:layout_alignParentRight="true"
                android:background="#fff"
                android:padding="1dp" />
               <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/hsvimage2"
                android:layout_width="148dp"
                android:layout_height="90dp"
                android:layout_marginRight="6dp"
                android:layout_alignParentRight="true"
                android:background="#000000"
                android:padding="1dp" />
               <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/hsvimage3"
                android:layout_width="148dp"
                android:layout_height="90dp"
                android:layout_marginRight="6dp"
                android:layout_alignParentRight="true"
                android:background="#CCC"
                android:padding="1dp" />
               <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/hsvimage4"
                android:layout_width="148dp"
                android:layout_height="90dp"
                android:layout_alignParentRight="true"
                android:background="#000000"
                android:padding="1dp" />
                        </LinearLayout>

                  </HorizontalScrollView>

    <Button
        android:id="@+id/bConfirm2"
        android:layout_width="90dp"
        android:layout_height="50dp"
        android:layout_below="@+id/isgallery"
        android:layout_centerHorizontal="true"
        android:alpha="0.7"
        android:layout_marginTop="10dp"
        android:background="@drawable/gray_bac"
        android:text="Confirm"
        android:textColor="#2B3856"
        android:textStyle="bold" />

     <ScrollView
        android:id="@+id/vsvdescription"
        android:layout_width="370dp"
        android:layout_height="250dp"
        android:layout_marginTop="7dp"
        android:layout_marginBottom="7dp" 
        android:padding="5dp"       

        android:layout_centerHorizontal="true"
        android:layout_below="@+id/dividertop"
         >

            <RelativeLayout
                android:orientation="vertical"
                android:gravity="center"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/sdescription"
        android:layout_width="370dp"
        android:layout_height="250dp"
        android:gravity="center"
        android:alpha="0.65"
        android:textColor="#ffffff"
        android:textSize="18sp" />

    </RelativeLayout>
    </ScrollView>

</RelativeLayout>

提前致谢

更新

public class CasualEventsSingleItemActivity extends Activity {

    // Declare Variables
    String list_item_name;
    String list_item_description;
    String list_item_price;
    String list_item_location;

    String single_list_item_description;




    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_events_single_item);


        ImageLoader mImageLoader = new ImageLoader(Volley.newRequestQueue(this),
                new ImageLoader.ImageCache() {
            private final LruCache<String, Bitmap>
                    cache = new LruCache<String, Bitmap>(20);

            @Override
            public Bitmap getBitmap(String url) {
                return cache.get(url);
            }

            @Override
            public void putBitmap(String url, Bitmap bitmap) {
                cache.put(url, bitmap);
            }
        });


        Intent i = getIntent();
        list_item_name = i.getStringExtra("list_item_name");
        list_item_location = i.getStringExtra("list_item_location");



        single_list_item_description = i.getStringExtra("single_list_item_description");

        TextView txtname = (TextView) findViewById(R.id.name);
        TextView txtlocation = (TextView) findViewById(R.id.location);
        TextView txtsdescription = (TextView) findViewById(R.id.sdescription);


        NetworkImageView hsvimage1 = (NetworkImageView) findViewById(R.id.hsvimage1);
        NetworkImageView hsvimage2 = (NetworkImageView) findViewById(R.id.hsvimage2);
        NetworkImageView hsvimage3 = (NetworkImageView) findViewById(R.id.hsvimage3);

        // Get image URLs from your previous network request...
        // I could not determine where this is stored from code in your question.
        String url1 = "list_item_bac";   // e.g. http://example.com/images/image1.png
        String url2 = "list_item_bac";
        String url3 = "list_item_bac ";

        // Set the URL of the image that should be loaded into this view, and
        // specify the ImageLoader that will be used to make the request.
        hsvimage1.setImageUrl(url1, mImageLoader);
        hsvimage2.setImageUrl(url2, mImageLoader);
        hsvimage3.setImageUrl(url3, mImageLoader);

        // Set results to the TextViews
        txtname.setText(list_item_name);
        txtlocation.setText(list_item_location);
        txtsdescription.setText(single_list_item_description);


        Button mConfirm2 = (Button)findViewById(R.id.bConfirm2);
        mConfirm2.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                ParseUser currentUser = ParseUser.getCurrentUser();

               // Create the class and the columns
                currentUser.saveInBackground();

                currentUser.put("ActivityName", list_item_name); 
                currentUser.saveInBackground(new SaveCallback() {
                    @Override
                    public void done(ParseException e) {
                        setProgressBarIndeterminateVisibility(false);

                        if (e == null) {
                            // Success!
                            Intent intent = new Intent(CasualEventsSingleItemActivity.this, usermatch.class);
                            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                            startActivity(intent);
                        }
                        else {
                            AlertDialog.Builder builder = new AlertDialog.Builder(CasualEventsSingleItemActivity.this);
                            builder.setMessage(e.getMessage())
                                .setTitle(R.string.signup_error_title)
                                .setPositiveButton(android.R.string.ok, null);
                            AlertDialog dialog = builder.create();
                            dialog.show();
                        }
                   }
               });
                //CasualEventsSingleItemActivity.this.startActivity(new Intent(CasualEventsSingleItemActivity.this, MatchingActivity.class));
            }
        });









    }
}

最佳答案

这是您获取 NPE 的代码

  * Constructs a new ImageLoader.
     * @param queue The RequestQueue to use for making image requests.
     * @param imageCache The cache to use as an L1 cache.
     */
    public ImageLoader(RequestQueue queue, ImageCache imageCache) {
        mRequestQueue = queue;
        mCache = imageCache;
    }

那么为什么要为第一个参数传递 null 呢？

Also as per the code
/**
 * Helper that handles loading and caching images from remote URLs.
 *
 * The simple way to use this class is to call {@link ImageLoader#get(String, ImageListener)}
 * and to pass in the default image listener provided by
 * {@link ImageLoader#getImageListener(ImageView, int, int)}. Note that all function calls to
 * this class must be made from the main thead, and all responses will be delivered to the main
 * thread as well.
 */

所以我会听取他们的建议并使用ImageLoader.get(String requestUrl，最终的ImageListener监听器)

关于java - 空点异常 - ImageLoader，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25560013/

文章推荐： jpa - 如何通过 EntityManager 从 InputStream 更新 BLOB？

文章推荐： macros - [Libre|Open]Office中当前文档的路径

文章推荐： asp.net-mvc-3 - MetadataType 缺少程序集引用

文章推荐： c - 短路和可读性

java - JGroups:发送(空，空，消息)与发送(地址，空，消息)
我已经为使用 JGroups 编写了简单的测试。有两个像这样的简单应用程序 import org.jgroups.*; import org.jgroups.conf.ConfiguratorFact
javascript - 空/空 json 如何检查它而不输出？
我有一个通过 ajax 检索的 json 编码数据集。我尝试检索的一些数据点将返回 null 或空。但是，我不希望将那些 null 或空值显示给最终用户，或传递给其他函数。我现在正在做的是检查
c# - 如果(值==空)与如果(空==值)
这个问题在这里已经有了答案: 关闭 11 年前。 Possible Duplicate: Why does one often see “null != variable” instead of “
java - 如果(空!=变量)为什么不如果(变量!=空)
嗨在我们公司，他们遵循与空值进行比较的严格规则。当我编码 if(variable!=null) 在代码审查中，我收到了对此的评论，将其更改为 if(null!=variable)。上面的代码对性能有影
typescript - Cordova 插件-qrscanner : error: no suitable constructor found for DefaultDecoderFactory(ArrayList, <空>，<空>)
我正在尝试使用 native Cordova QR 扫描仪插件编译项目，但是我不断收到此错误。据我了解，这是代码编写方式的问题，它向构造函数发送了错误的值，或者根本就没有找到构造函数。那么我该如何解决
Apache Nutch 错误 : Injector: java. io.IOException:命令字符串中的(空)条目:空 chmod 0644
我在装有 Java 1.8 的 Windows 10 上使用 Apache Nutch 1.14。我已按照 https://wiki.apache.org/nutch/NutchTutorial 中提
SQL为空且=空
这个问题已经有答案了: 已关闭11 年前。 Possible Duplicate: what is “=null” and “ IS NULL” Is there any difference bet
空-三眼乌鸦
Three-EyedRaven 内网渗透初期，我们都希望可以豪无遗漏的尽最大可能打开目标内网攻击面，故，设计该工具的初衷是解决某些工具内网探测速率慢、运行卡死、服务爆破误报率高以及socks流
Scala-空(？)作为命名Int参数的默认值
我想在Scala中像在Java中那样做: public void recv(String from) { recv(from, null); } public void recv(String
python - 空/无SIFT描述符和在python中生成的关键点
我正在尝试从一组图像补丁中创建一个密码本。我已将图像(Caltech 101)分成20 X 20图像块。我想为每个补丁创建一个SIFT描述符。但是对于某些图像补丁，它不返回任何描述符/关键点。我尝试使
spring - @Autowire注释的问题(空)
我在验证器类中自动连接的两个服务有问题。这些服务工作正常，因为在我的 Controller 中是自动连接的。我有一个 applicationContext.xml 文件和 MyApp-servlet.
java - 空 while 循环的线程问题
已关闭。此问题不符合Stack Overflow guidelines 。目前不接受答案。已关闭10 年前。问题必须表现出对要解决的问题的最低程度的了解。告诉我们您尝试过做什么，为什么不起作用，以
php - mysql_num_rows 空
大家好，我正在对数据库进行正常的选择，但是 mysql_num_rowsis 为空，我不知道为什么，我有 7 行选择。如果您发现问题，请告诉我。真的谢谢。代码如下: function get_b
ios - 打印出连接的字符串显示(空)
我想以以下格式创建一个字符串:id[]=%@&stringdata[]=%@&id[]=%@&stringdata[]=%@&id[]=%@&stringdata[]=%@&等，在for循环中，我得到
ios - stringWithContentsOfURL返回(空)
我正在尝试使用以下代码将URL转换为字符串: NSURL *urlOfOpenedFile = _service.myURLRequest.URL; NSString *fileThatWasOpen
iphone - 将UInt32传递给NSData对象返回(空)
我正在尝试将NSNumber传递到正在工作的UInt32中。然后，我试图将UInt32填充到NSData对象中。但是，这在这里变得有些时髦... 当我尝试将NSData对象中的内容写成它返回的字符串(
java - 服务器cookie=空
我正在进行身份验证并收到空 cookie。我想存储这个 cookie，但服务器没有返回给我 cookie。但响应代码是 200 ok。 httpConn.setRequestProperty(
java - 简单的菜鸟应用程序每次都会崩溃..(空)？
我认为 Button bTutorial1 = (Button) findViewById(R.layout.tutorial1); bTutorial1.setOnClickListener
jsp - 如何在JSTL中查找HashMap是否为空/空？
我的 Controller 中有这样的东西: model.attribute("hiringManagerMap",hiringManagerMap); 我正在访问此 hiringManagerMap
jQuery 空() ListView
我想知道如何以正确的方式清空列表。在 div 中有一个列表然后清空 div 或列表更好吗？我知道这是一个蹩脚的问题，但请帮助我理解这个 empty() 函数:) 案例)如果我运行这个脚本会发生什么:

行者123

个人简介

我是一名优秀的程序员,十分优秀！

作者热门文章

滴滴打车优惠券免费领取

全站热门文章

首页

博学

6Ren·AI

商城

java - 空点异常 - ImageLoader