尝试在Android Studio中使用jsoup提取毕加索错误

问题描述

因此，我试图从网站，图像和标题中获取数据，并使用Picasso库将其加载到recylerview中，但是当应用程序启动时，它停止工作并且出现错误。

protected Void doInBackground(Void... voids) {
        try {
            String url = "https://www.example.com";
            Document doc = Jsoup.connect(url).get();

            Elements data = doc.select("span.thumbnail");

            int size = data.size();
            for (int i = 0; i < size; i++){
                String imgurl = data.select("span.thumbnail")
                        .select("img")
                        .eq(i)
                        .attr("src");
                String title = data.select("h4.titles")
                        .select("span")
                        .eq(i)
                        .text();
                parseItems.add(new ParseItem(imgurl,title));
                Log.d("items","img: " + imgurl + " .title: " + title);
            }

        } catch (IOException e) {
            e.printstacktrace();
        }

我也用

调用图书馆

implementation 'androidx.recyclerview:recyclerview:1.0.0'
implementation 'androidx.cardview:cardview:1.0.0'
implementation 'com.squareup.picasso:picasso:2.71828'
implementation 'org.jsoup:jsoup:1.13.1'

运行该应用程序时，出现以下错误

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.event_finder,PID: 8531
java.lang.IllegalArgumentException: Path must not be empty.
    at com.squareup.picasso.Picasso.load(Picasso.java:332)
    at com.example.event_finder.ParseAdapter.onBindViewHolder(ParseAdapter.java:38)
    at com.example.event_finder.ParseAdapter.onBindViewHolder(ParseAdapter.java:17)
    at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:7065)
    at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:7107)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:6012)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6279)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6118)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6114)
    at androidx.recyclerview.widget.linearlayoutmanager$LayoutState.next(linearlayoutmanager.java:2303)
    at androidx.recyclerview.widget.linearlayoutmanager.layoutChunk(linearlayoutmanager.java:1627)
    at androidx.recyclerview.widget.linearlayoutmanager.fill(linearlayoutmanager.java:1587)
    at androidx.recyclerview.widget.linearlayoutmanager.onLayoutChildren(linearlayoutmanager.java:665)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
    at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4404)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1849)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at androidx.appcompat.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:530)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1829)
    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1673)
    at android.widget.LinearLayout.onLayout(LinearLayout.java:1582)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
    at com.android.internal.policy.DecorView.onLayout(DecorView.java:784)
    at android.view.View.layout(View.java:22844)
    at android.view.ViewGroup.layout(ViewGroup.java:6389)
    at android.view.ViewRootImpl.performlayout(ViewRootImpl.java:3470)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2938)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1952)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:8171)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:972)
    at android.view.Choreographer.doCallbacks(Choreographer.java:796)
    at android.view.Choreographer.doFrame(Choreographer.java:731)
    at android.view.Choreographer$FramedisplayEventReceiver.run(Choreographer.java:957)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)

E / AndroidRuntime：在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:592）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:947）

编辑：

at com.squareup.picasso.Picasso.load（Picasso.java:332）

public RequestCreator load(@Nullable String path) {
    if (path == null) {
      return new RequestCreator(this,null,0);
    }
    if (path.trim().length() == 0) {
      throw new IllegalArgumentException("Path must not be empty.");  **this line**
    }
    return load(Uri.parse(path));
  }

，位于com.example.event_finder.ParseAdapter.onBindViewHolder（ParseAdapter.java:38）

    public void onBindViewHolder(@NonNull ParseAdapter.ViewHolder holder,int position) {
    ParseItem parseItem = parseItems.get(position);
    holder.textView.setText(parseItem.getTitle());
    Picasso.get().load(parseItem.getimgurl()).into(holder.imageView);   **this line**
}

，位于com.example.event_finder.ParseAdapter.onBindViewHolder（ParseAdapter.java:17）

public class ParseAdapter extends RecyclerView.Adapter<ParseAdapter.ViewHolder> {

解决方法

parseItem.getImgUrl() ParseAdapter.java:38

按照它的产生方式（向后），我们可以看到ParseItem parseItem = parseItems.get(position);（ParseAdapter.java:36）收到了position作为索引（来自传入的方法参数）。该索引引用列表中的空字符串。

由于您正在将新的ParseItem作为JSoup代码的一部分添加到我假设的列表（？）中，因此看来

imgUrl在

中：

            String url = "https://www.example.com";
            Document doc = Jsoup.connect(url).get();

            Elements data = doc.select("span.thumbnail");

            int size = data.size();
            for (int i = 0; i < size; i++){
                String imgUrl = data.select("span.thumbnail")
                        .select("img")
                        .eq(i)
                        .attr("src");

返回一个空的String（""），您正在ParseItem s列表中填充它

android-studio java java jsoup picasso picasso