使用SAXparser獲取信息到多個元素（Android）

Question

我是Android新手（也是Java），但現在我開始使用Web服務。

因此，爲了更好地瞭解如何解析XML，我開始嘗試本教程：

http://www.anddev.org/novice-tutorials-f8/parsing-xml-from-the-net-using-the-saxparser-t353.html

與此示例中使用的XML：

<outertag> 
<innertag sampleattribute="innertagAttribute"> 
<mytag>anddev.org rulez =)</mytag> 
<tagwithnumber thenumber="1337"/> 
</innertag> 
</outertag> 

我理解它是如何工作的（我猜），但如果XML是這樣的：

<outertag> 
<innertag sampleattribute="innertagAttribute"> 
<mytag>anddev.org rulez =)</mytag> 
<tagwithnumber thenumber="1337"/> 
</innertag> 
<innertag sampleattribute="innertagAttribute2"> 
<mytag>something</mytag> 
<tagwithnumber thenumber="14214"/> 
</innertag> 
</outertag> 

在應用程序的類中需要改變什麼來獲取各種元素的數據？

我明白任何sugestion ...

完整的源代碼：

• ParseXML.java

  包org.anddev.android.parsingxml;

  import java.net.URL;

  import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory;

  import org.xml.sax.InputSource; import org.xml.sax.XMLReader;

  import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.widget.TextView;

  公共類ParsingXML延伸活動{

  private final String MY_DEBUG_TAG = "WeatherForcaster"; 
  
  /** Called when the activity is first created. */ 
  @Override 
  public void onCreate(Bundle icicle) { 
      super.onCreate(icicle); 
  
      /* Create a new TextView to display the parsingresult later. */ 
      TextView tv = new TextView(this); 
      try { 
       /* Create a URL we want to load some xml-data from. */ 
       URL url = new URL("http://www.anddev.org/images/tut/basic/parsingxml/example.xml"); 
  
       /* Get a SAXParser from the SAXPArserFactory. */ 
       SAXParserFactory spf = SAXParserFactory.newInstance(); 
       SAXParser sp = spf.newSAXParser(); 
  
       /* Get the XMLReader of the SAXParser we created. */ 
       XMLReader xr = sp.getXMLReader(); 
       /* Create a new ContentHandler and apply it to the XML-Reader*/ 
       ExampleHandler myExampleHandler = new ExampleHandler(); 
       xr.setContentHandler(myExampleHandler); 
  
       /* Parse the xml-data from our URL. */ 
       xr.parse(new InputSource(url.openStream())); 
       /* Parsing has finished. */ 
  
       /* Our ExampleHandler now provides the parsed data to us. */ 
       ParsedExampleDataSet parsedExampleDataSet = 
             myExampleHandler.getParsedData(); 
  
       /* Set the result to be displayed in our GUI. */ 
       tv.setText(parsedExampleDataSet.toString()); 
  
      } catch (Exception e) { 
       /* Display any Error to the GUI. */ 
       tv.setText("Error: " + e.getMessage()); 
       Log.e(MY_DEBUG_TAG, "WeatherQueryError", e); 
      } 
      /* Display the TextView. */ 
      this.setContentView(tv); 
  } 
  

  }

• ExampleHandler

  包org.anddev.android.parsingxml;

  import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler;

  公共類ExampleHandler延伸的DefaultHandler {

  // =========================================================== 
  // Fields 
  // =========================================================== 
  
  private boolean in_outertag = false; 
  private boolean in_innertag = false; 
  private boolean in_mytag = false; 
  
  private ParsedExampleDataSet myParsedExampleDataSet = new ParsedExampleDataSet(); 
  
  // =========================================================== 
  // Getter & Setter 
  // =========================================================== 
  
  public ParsedExampleDataSet getParsedData() { 
      return this.myParsedExampleDataSet; 
  } 
  
  // =========================================================== 
  // Methods 
  // =========================================================== 
  @Override 
  public void startDocument() throws SAXException { 
      this.myParsedExampleDataSet = new ParsedExampleDataSet(); 
  } 
  
  @Override 
  public void endDocument() throws SAXException { 
      // Nothing to do 
  } 
  
  /** Gets be called on opening tags like: 
  * <tag> 
  * Can provide attribute(s), when xml was like: 
  * <tag attribute="attributeValue">*/ 
  @Override 
  public void startElement(String namespaceURI, String localName, 
       String qName, Attributes atts) throws SAXException { 
      if (localName.equals("outertag")) { 
       this.in_outertag = true; 
      }else if (localName.equals("innertag")) { 
       this.in_innertag = true; 
      }else if (localName.equals("mytag")) { 
       this.in_mytag = true; 
      }else if (localName.equals("tagwithnumber")) { 
       // Extract an Attribute 
       String attrValue = atts.getValue("thenumber"); 
       int i = Integer.parseInt(attrValue); 
       myParsedExampleDataSet.setExtractedInt(i); 
      } 
  } 
  
  /** Gets be called on closing tags like: 
  * </tag> */ 
  @Override 
  public void endElement(String namespaceURI, String localName, String qName) 
       throws SAXException { 
      if (localName.equals("outertag")) { 
       this.in_outertag = false; 
      }else if (localName.equals("innertag")) { 
       this.in_innertag = false; 
      }else if (localName.equals("mytag")) { 
       this.in_mytag = false; 
      }else if (localName.equals("tagwithnumber")) { 
       // Nothing to do here 
      } 
  } 
  
  /** Gets be called on the following structure: 
  * <tag>characters</tag> */ 
  @Override 
  public void characters(char ch[], int start, int length) { 
      if(this.in_mytag){ 
       myParsedExampleDataSet.setExtractedString(new String(ch, start, length)); 
      } 
  } 
  

  }

• ParsedExampleDataSet

  包org.anddev.android。parsingxml;

  public class ParsedExampleDataSet {0}私人String extractedString = null; private int extractedInt = 0;

  public String getExtractedString() { 
      return extractedString; 
  } 
  public void setExtractedString(String extractedString) { 
      this.extractedString = extractedString; 
  } 
  
  public int getExtractedInt() { 
      return extractedInt; 
  } 
  public void setExtractedInt(int extractedInt) { 
      this.extractedInt = extractedInt; 
  } 
  
  public String toString(){ 
      return "ExtractedString = " + this.extractedString 
        + "nExtractedInt = " + this.extractedInt; 
  } 
  

  }

Answer 1

問題解決了！

貝婁是網站提供有用的信息：

• https://stackoverflow.com/a/4828765
• https://stackoverflow.com/a/5709544
• http://as400samplecode.blogspot.com/2011/11/android-parse-xml-file-example-using.html
• http://www.anddev.org/novice-tutorials-f8/parsing-xml-from-the-net-using-the-saxparser-t353.html

我最初的問題是我應該如何定義類的數據我想從XML中提取。在瞭解了我應該怎麼做（查看JAVA編程的基本概念）後，我將ExampleHandler返回的數據類型更改爲ArrayList <「您想要返回的數據的類」>。

我在下面給出一個例子：一個XML的

• 比如你要解析：

  <outertag> 
  <cartag type="Audi"> 
      <itemtag name="model">A4</itemtag> 
      <itemtag name="color">Black</itemtag> 
      <itemtag name="year">2005</itemtag> 
  </cartag> 
  <cartag type="Honda"> 
      <itemtag name="model">Civic</itemtag> 
      <itemtag name="color">Red</itemtag> 
      <itemtag name="year">2001</itemtag> 
  </cartag> 
  <cartag type="Seat"> 
      <itemtag name="model">Leon</itemtag> 
      <itemtag name="color">White</itemtag> 
      <itemtag name="year">2009</itemtag> 
  </cartag> 
  </outertag> 
  

所以在這裏，你應該定義一個類 「汽車」 與適當的屬性（字符串類型，型號，顏色，年;），制定者和獲得者...

• 我對這個XML ExampleHandler的建議是：

公共類ExampleHandler，你可以在活動的分析數據使用擴展的DefaultHandler {

// =========================================================== 
// Fields 
// =========================================================== 

private int numberOfItems=3;  
private boolean in_outertag = false; 
private boolean in_cartag = false; 
private boolean[] in_itemtag = new boolean[numberOfItems]; 

Car newCar = new Car(); 

private ArrayList<Car> list = new ArrayList<Car>(); 

// =========================================================== 
// Getter & Setter 
// =========================================================== 

public ArrayList<Car> getParsedData() { 
    return this.list; 
} 

// =========================================================== 
// Methods 
// =========================================================== 
@Override 
public void startDocument() throws SAXException { 
    this.list = new ArrayList<Car>(); 
} 

@Override 
public void endDocument() throws SAXException { 
    // Nothing to do 
} 

/** Gets be called on opening tags like: 
* <tag> 
* Can provide attribute(s), when xml was like: 
* <tag attribute="attributeValue">*/ 
@Override 
public void startElement(String namespaceURI, String localName, 
     String qName, Attributes atts) throws SAXException { 
    if (localName.equals("outertag")) { 
     this.in_outertag = true; 
    }else if (localName.equals("cartag")) { 
     this.in_cartag = true; 
     newCar.setType(atts.getValue("type")); //setType(...) is the setter defined in car class 
    }else if (localName.equals("itemtag")) { 
     if((atts.getValue("name")).equals("model")){ 
      this.in_itemtag[0] = true; 
     }else if((atts.getValue("name")).equals("color")){ 
      this.in_itemtag[1] = true; 
     }else if((atts.getValue("name")).equals("year")){ 
      this.in_itemtag[2] = true; 
     } 
    } 
} 

/** Gets be called on closing tags like: 
* </tag> */ 
@Override 
public void endElement(String namespaceURI, String localName, String qName) 
     throws SAXException { 
    if (localName.equals("outertag")) { 
     this.in_outertag = false; 
    }else if (localName.equals("cartag")) { 
     this.in_cartag = false; 
     Car carTemp = new Car(); 
     carTemp.copy(newCar, carTemp); //this method is defined on car class, and is used to copy the 
             //properties of the car to another Object car to be added to the list 
     list.add(carTemp); 
    }else if (localName.equals("itemtag")){ 
     if(in_itemtag[0]){ 
      this.in_itemtag[0] = false; 
     }else if(in_itemtag[1]){ 
      this.in_itemtag[1] = false; 
     }else if(in_itemtag[2]){ 
      this.in_itemtag[2] = false; 
     } 
    } 
} 

/** Gets be called on the following structure: 
* <tag>characters</tag> */ 
@Override 
public void characters(char ch[], int start, int length) { 

    if(in_itemtag[0]){ 
     newCar.setModel(new String(ch, start, length)); 
    }else if(in_itemtag[1]){ 
     newCar.setColor(new String(ch, start, length)); 
    }else if(in_itemtag[2]){ 
     newCar.setYear(new String(ch, start, length)); 
    } 
} 

}

在此之後：

... 
ArrayList<Car> ParsedData = myExampleHandler.getParsedData(); 
... 

我希望這可以幫助別人。

注意：我沒有測試完全一樣，但幾乎是相同的我的解決辦法，所以應該工作...

而且我的英語不好對不起......