Android Jsoup-解析图像时出现NullPointerException

Question

I am using Jsoup in my Android app to get images from the internet but an getting a NullPointerException. Java:

public class CollegeInfo extends Activity{

TextView body;
ImageView image1;ImageView image2;ImageView image3;ImageView image4;
ImageView image8;ImageView image7;ImageView image6;ImageView image5;
String college;
String ataglance;
double satHigh;
double satLow;
Bitmap[] bitmap;
String[] imgSrcs;InputStream[] input;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.collegeinfo);
    Bundle extras = getIntent().getExtras();
    if (extras != null) {
        college  = extras.getString("tag");
    }
    SpannableStringBuilder buffer = new SpannableStringBuilder();
    body = (TextView) findViewById(R.id.title);
    image1 = (ImageView) findViewById(R.id.imageView1);
    image2 = (ImageView) findViewById(R.id.imageView2);
    image3 = (ImageView) findViewById(R.id.imageView3);
    image4 = (ImageView) findViewById(R.id.imageView4);
    image5 = (ImageView) findViewById(R.id.imageView5);
    image6 = (ImageView) findViewById(R.id.imageView6);
    image7 = (ImageView) findViewById(R.id.imageView7);
    image8 = (ImageView) findViewById(R.id.imageView8);
        try {
            Document doc = Jsoup.connect("http://www.forbes.com/colleges/"+college+"/").get();
            String name = doc.select("meta[name=keywords]").attr("content");
            int nameLen = name.length();
            buffer.append(name+"\n");
            String city = doc.select("ul[class=address]").select("li").first().text();
            buffer.append(city+"\n");
            ataglance = "";
            for(int i=0;i<8;i++){                   
                ataglance += doc.select("div[class=ataglanz fleft]").select("li").get(i).ownText()+" ";
                ataglance += doc.select("div[class=ataglanz fleft]").select("b").get(i).text();
                ataglance += "\n";
            }
            String satRange = doc.select("div[class=ataglanz fleft]").select("b").get(8).text();
            int satLength = satRange.length();
            try{
                satHigh = Double.parseDouble(satRange.substring(satLength-4, satLength));
                satLow = Double.parseDouble(satRange.substring(0, satLength-5));
            }catch(NumberFormatException e){
                e.printStackTrace();
            }
            satHigh*=1.5; satLow*=1.5;
            int satL = (int) Math.round(satLow); int satH = (int) Math.round(satHigh);
            ataglance += "SAT Composite Range: "+Integer.toString(satL)+"-"+Integer.toString(satH);
            buffer.append(ataglance+"\n");
            for(int i = 0;i<8;i++){
                Elements img = doc.select("div[id=photos]").select("a");
                imgSrcs[i] = img.text();
                input[i] = new java.net.URL(imgSrcs[i]).openStream();
                bitmap[i] = BitmapFactory.decodeStream(input[i]);   
            }
            image1.setImageBitmap(bitmap[0]);
            image2.setImageBitmap(bitmap[1]);
            image3.setImageBitmap(bitmap[2]);
            image4.setImageBitmap(bitmap[3]);
            image5.setImageBitmap(bitmap[4]);
            image6.setImageBitmap(bitmap[5]);
            image7.setImageBitmap(bitmap[6]);
            image8.setImageBitmap(bitmap[7]);


            body.setText(buffer.toString());
        }catch(IOException e){
                e.printStackTrace();
            }


}
    {
    if (android.os.Build.VERSION.SDK_INT > 9) {
        StrictMode.ThreadPolicy policy = 
                new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        }
}
}

XML:

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <HorizontalScrollView
        android:id="@+id/horizontalScrollView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.06" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <ImageView
                android:id="@+id/imageView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView6"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imageView7"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
            <ImageView
                android:id="@+id/imageView8"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>

        </LinearLayout>

    </HorizontalScrollView>

</LinearLayout>

Before I added in the images, everything was working fine, so I believe that I am not parsing the images correctly.

Logcat:

07-29 17:19:49.985: E/AndroidRuntime(10855): FATAL EXCEPTION: main
07-29 17:19:49.985: E/AndroidRuntime(10855): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.collegeselector/com.collegeselector.CollegeInfo}: java.lang.NullPointerException
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.os.Looper.loop(Looper.java:137)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread.main(ActivityThread.java:5039)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at java.lang.reflect.Method.invokeNative(Native Method)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at java.lang.reflect.Method.invoke(Method.java:511)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at dalvik.system.NativeStart.main(Native Method)
07-29 17:19:49.985: E/AndroidRuntime(10855): Caused by: java.lang.NullPointerException
07-29 17:19:49.985: E/AndroidRuntime(10855):    at com.collegeselector.CollegeInfo.onCreate(CollegeInfo.java:87)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.Activity.performCreate(Activity.java:5104)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
07-29 17:19:49.985: E/AndroidRuntime(10855):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
07-29 17:19:49.985: E/AndroidRuntime(10855):    ... 11 more

What should I change to get the images to work?

Answer 1

Look at your stacktrace:

07-29 17:19:49.985: E/AndroidRuntime(10855): Caused by: java.lang.NullPointerException
07-29 17:19:49.985: E/AndroidRuntime(10855):    at com.collegeselector.CollegeInfo.onCreate(CollegeInfo.java:87)

You haven't initialized the string array String[] imgSrcs; yet you try to add content to it in your for each loop:

imgSrcs[i] = img.text();

Also, the size of an array cannot be modified, so you either decide upon a size of it when you initialize it and then stick with it. If you want a dynamic size, use an ArrayList object instead.