Question

我已经获得了将XML数据解析为基本列表视图然后进入文本视图的任务，但问题是在编辑有意为练习提供的代码时，一旦我按下“登录”按钮，我的应用程序就会停止关于主要活动。感谢高级读者阅读此内容，我真的很茫然，我一直试图将它调整好几个小时。

我想知道是否有人能找到问题。

package com.example.beaconhomesproject;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.sax.Element;
import android.sax.EndElementListener;
import android.sax.EndTextElementListener;
import android.sax.RootElement;
import android.util.Xml;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class Bill extends Activity {
private ArrayList<BillListView> bill;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_bill);

    // Download
    new DownloadBillListTask()
            .execute("http://www.fcet.staffs.ac.uk/pfb1/IMWTAssignment/bills.xml");
    // Adds a CLick Listener to the list view
    ListView listView = (ListView) findViewById(R.id.bill_list);
    listView.setOnItemClickListener(new ListView.OnItemClickListener() {

        // Opens a new Activity when an item is clicked
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            Intent intent = new Intent(view.getContext(), `enter code here`BillDetails.class);
            intent.putExtra("BillListView", bill.get(position));
            startActivity(intent);
        }
    });
}

// get xml
public ArrayList<BillListView> ParseBillsFromXML(String XMLURL) {
    final ArrayList<BillListView> values = new ArrayList<BillListView>();
    final BillListView LeBill = new BillListView();

    // Convert our string into a URL
    URL feedUrl;
    try {
        feedUrl = new URL(XMLURL);
    } catch (MalformedURLException e) {
        throw new RuntimeException(e);
    }

    // Get the RootElement of our XML file which is Students
    RootElement root = new RootElement("Bills");
    Element bill = root.getChild("bill"); // Then list our element we want,
                                            // so a single Student

    // Our End Element Listener event fires when we get the end of a
    // complete Student tag
    bill.setEndElementListener(new EndElementListener() {
        @Override
        public void end() {
            values.add(LeBill.copy());
        }
    });

    // All of the End Text Element Listeners get the body of the child tags
    // of a bill
    bill.getChild("date").setEndTextElementListener(
            new EndTextElementListener() {
                @Override
                public void end(String body) {
                    LeBill.setDate(body);
                }
            });
    bill.getChild("type").setEndTextElementListener(
            new EndTextElementListener() {
                @Override
                public void end(String body) {
                    LeBill.setType(body);
                }
            });
    bill.getChild("price").setEndTextElementListener(
            new EndTextElementListener() {
                @Override
                public void end(String body) {
                    LeBill.setPrice(body);
                }
            });

    // Now we have set up all our event listeners, we can start to parse the
    // document
    try {
        Xml.parse(feedUrl.openConnection().getInputStream(),
                Xml.Encoding.UTF_8, root.getContentHandler());
    } catch (Exception e) {
        throw new RuntimeException(e);
    }

    // We can then return all our returns values after parsing
    return values;
}

// This is an inner class which runs Asynchronously (In the background)
// It needs to be told the three types it accepts
// String is the type that is passed to doInBackground
// Void is the type that is used if we report any progress (We don't in this
// case so its Void!)
// ArrayList<Student> is the data type that is returned from our background
// task and is passed to final function
class DownloadBillListTask extends
        AsyncTask<String, Void, ArrayList<BillListView>> {

    // This is the code that runs in the background - We can't update any UI
    // in this function!
    // String... basically means we are passing in a list of strings but we
    // don't specify how many!
    @Override
    protected ArrayList<BillListView> doInBackground(String... arg0) {

        // This calls our Parse function above
        return ParseBillsFromXML(arg0[0]);
    }

    // This executes back on the UI thread so we can actually update the UI
    // here
    @Override
    protected void onPostExecute(ArrayList<BillListView> result) {
        // Save our result to our class level students ArrayList
        bill = result;

        // Set the list view to display the list we just downloaded!
        ListView listView = (ListView) findViewById(R.id.bill_list);

        ArrayAdapter<BillListView> adapter = new ArrayAdapter<BillListView>(
                getBaseContext(), android.R.layout.simple_list_item_1,
                result);

        listView.setAdapter(adapter);
    }

}

public void movemain(View view) {
    Intent intent = new Intent(this, MainActivity.class);
    startActivity(intent);
}


}

XML：

   <ImageView
    android:id="@+id/waterlogo"
    android:layout_width="100dp"
    android:layout_height="80dp"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:contentDescription="@string/welcome"
    android:scaleType="fitXY"
    android:src="@drawable/water" />


     <View
        android:id="@+id/viewyview"
        android:layout_width="fill_parent"
        android:layout_height="2dp"
        android:background="#e47c0b" 
        android:layout_below="@id/waterlogo"/>
         <ListView
    android1:id="@+id/bill_list"
    android1:layout_width="match_parent"
    android1:layout_height="match_parent"
    android1:layout_alignTop="@+id/viewyview" />

    <Button
    android:id="@+id/backbutton"
    android:layout_width="100dip"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="@android:color/transparent"
    android:gravity="center"
    android:onClick="moveback"
    android:text="@string/back"
    android:textColor="#e47c0b" />



</RelativeLayout>

Log cat：

>04-22 14:39:14.965: E/AndroidRuntime(1053): FATAL EXCEPTION: AsyncTask #3
>04-22 14:39:14.965: E/AndroidRuntime(1053): java.lang.RuntimeException: An error occured while executing doInBackground()
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.FutureTask.run(FutureTask.java:239)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.lang.Thread.run(Thread.java:856)
>04-22 14:39:14.965: E/AndroidRuntime(1053): Caused by: java.lang.RuntimeException: android.sax.BadXmlException: Line 1: Root element name does not match. Expected: 'Bills', Got: 'bills'
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at com.example.beaconhomesproject.Bill.ParseBillsFromXML(Bill.java:103)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at com.example.beaconhomesproject.Bill$DownloadBillListTask.doInBackground(Bill.java:128)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at com.example.beaconhomesproject.Bill$DownloadBillListTask.doInBackground(Bill.java:1)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    ... 4 more
>04-22 14:39:14.965: E/AndroidRuntime(1053): Caused by: android.sax.BadXmlException: Line 1: Root element name does not match. Expected: 'Bills', Got: 'bills'
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.sax.RootElement$Handler.startRoot(RootElement.java:145)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.sax.RootElement$Handler.startElement(RootElement.java:116)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatParser.startElement(ExpatParser.java:143)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatParser.appendBytes(Native Method)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatParser.parseFragment(ExpatParser.java:513)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatParser.parseDocument(ExpatParser.java:474)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatReader.parse(ExpatReader.java:321)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at org.apache.harmony.xml.ExpatReader.parse(ExpatReader.java:279)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at android.util.Xml.parse(Xml.java:84)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    at com.example.beaconhomesproject.Bill.ParseBillsFromXML(Bill.java:100)
>04-22 14:39:14.965: E/AndroidRuntime(1053):    ... 8 more

Answer 1

这是你的问题：

14:39:14.965: E/AndroidRuntime(1053): Caused by: java.lang.RuntimeException: android.sax.BadXmlException: Line 1: Root element name does not match. Expected: 'Bills', Got: 'bills'

所以：

RootElement root = new RootElement("bills");

Android应用程序的运行时异常问题。

1 个答案: