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我正在使用 SAX 解析方法从 Web 服务器获取数据所有数据都显示在 LogCat 中，但未显示在我的模拟器中

@SuppressLint("NewApi")
    public class IotdHandler extends DefaultHandler {
    private String url = "http://www.nasa.gov/rss/dyn/image_of_the_day.rss";
    private boolean inUrl = false;
    private boolean inTitle = false;
    private boolean inDescription = false;
    private boolean inItem = false;
    private boolean inDate = false;
    private static Bitmap image = null;
    private String imageUrl=null;
    private static String title = null;
    private static StringBuffer description = new StringBuffer();
    private static String date = null;

    public void processFeed() {
    try {
    //This part is added to allow the network connection on a main GUI thread...    
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy); 
    SAXParserFactory factory = SAXParserFactory.newInstance();
    SAXParser parser = factory.newSAXParser();
    XMLReader reader = parser.getXMLReader();
    reader.setContentHandler(this);
    URL urlObj = new URL(url);
    InputStream inputStream = urlObj.openConnection().getInputStream();
    reader.parse(new InputSource(inputStream));
    } 
    catch (Exception e) 
    {
        e.printStackTrace();
        System.out.println(new String("Got Exception General"));
    }
    }

    private Bitmap getBitmap(String url) {
    try {
        System.out.println(url);
    HttpURLConnection connection =
    (HttpURLConnection)new URL(url).openConnection();
    connection.setDoInput(true);
    connection.connect();
    InputStream input = connection.getInputStream();
    Bitmap bitmap = BitmapFactory.decodeStream(input);
    input.close();
    return bitmap;
    } 
    catch (IOException ioe) 
    {
        System.out.println(new String("IOException in reading Image"));
        return null;
    }
    catch (Exception ioe) 
    {
        System.out.println(new String("IOException GENERAL"));
        return null;
    }
    }

    public void startElement(String uri, String localName, String qName,
    Attributes attributes) throws SAXException 
    {

    if (localName.equals("enclosure"))
    {
        System.out.println(new String("characters Image"));
        imageUrl = attributes.putValue("","url");
        System.out.println(imageUrl);
        inUrl = true; 
    }
    else { inUrl = false; }
    if (localName.startsWith("item")) { inItem = true; }
    else if (inItem) {
    if (localName.equals("title")) { inTitle = true; }
    else { inTitle = false; }
    if (localName.equals("description")) { inDescription = true; }
    else { inDescription = false; }
    if (localName.equals("pubDate")) { inDate = true; }
    else { inDate = false; }
    }
    }

    public void characters(char ch[], int start, int length) {
        System.out.println(new String("characters"));
    String chars = new String(ch).substring(start, start + length);
    System.out.println(chars);
    if (inUrl && image == null) 
    {
        System.out.println(new String("IMAGE"));
        System.out.println(imageUrl);
        image = getBitmap(imageUrl);
    }
    if (inTitle && title == null) {
        System.out.println(new String("TITLE"));
        title = chars; }
    if (inDescription) { description.append(chars); }
    if (inDate && date == null) { date = chars; }
    }

    public static Bitmap getImage() { return image; }
    public static String getTitle() { return title; }
    public static StringBuffer getDescription() { return description; }
    public static String getDate() { return date; }

    }

这是我的 MainActivity 类我正在尝试从 nasa rss 提要中获取数据所有数据都显示在 logcat 中但未显示在模拟器中

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        IotdHandler handler = new IotdHandler(); //create handler
        handler.processFeed(); //start parsing
       resetDisplay(IotdHandler.getTitle(), IotdHandler.getDate(),
                IotdHandler.getImage(), IotdHandler.getDescription());
    }



    private void resetDisplay(String title, String date, Bitmap image, StringBuffer description)
    {
        TextView titleView = (TextView)findViewById(R.id.imageTitle);
        titleView.setText(title);

        TextView dateView = (TextView)findViewById(R.id.imageDate);
        dateView.setText(date);

        ImageView imageView = (ImageView)findViewById(R.id.imageDisplay);

        imageView.setImageBitmap(image);

        TextView descriptionView = (TextView)findViewById(R.id.imageDescription);
        descriptionView.setText(description);

    }
    }
4

1 回答 1

0

包含属性的类：

public class ImageDetails {
    private String imageDate, imageTitle, imageDesc;
    // getters and setters here
}

在 IOHandler 类中，在 startElement 函数中，添加这个，

if(qName.equalsIgnoreCase("channel") {
    imageDetails = new ImageDetails();
    // make sure imageDetails is declared in the class
}

此行在找到开始标记通道时实例化 imgedetails 类，并且由于提要只有一项，因此它只会被实例化一次。

在 IOHandler 类中进行的其他更改

创建一个类似的函数

public ImageDetails getImageDetails() {
    // call the function that reads the documents or parses it
    return imageDetails;
}

每当本地名称匹配时，使用 setter 方法来设置值。

在活动类中创建 IOHandler 的实例

IOHandler ioHandler = new IOHandler(pass values if needed);
ImageDetails imageDetails = ioHandler.getImageDetails();

使用 imageDetails.getter 方法用数据填充文本视图。

======== 编辑#1

将 startElement 函数更改为：

 @Override
public void startElement(String uri, String localName, String qName,
        org.xml.sax.Attributes attributes) throws SAXException {
    super.startElement(uri, localName, qName, attributes);

     if (qName.equals("enclosure"))
        {
            System.out.println(new String("characters Image"));
            //imageUrl = attributes.putValue("","url");
            // I have commented out this line, try to figure out how to get this atleast
            System.out.println(imageUrl);
            inUrl = true; 
        }
        else { inUrl = false; }
        if (qName.startsWith("item")) { inItem = true; }
        else if (inItem) {
        if (qName.equals("title")) { inTitle = true; }
        else { inTitle = false; }
        if (qName.equals("description")) { inDescription = true; }
        else { inDescription = false; }
        if (qName.equals("pubDate")) { inDate = true; }
        else { inDate = false; }
        }
        }

}

希望这可以帮助。

于 2013-10-20T00:59:37.327 回答