使用SAXparser将信息获取多个元素(Android)
作者：互联网
我是Android(和Java)的新用户,但现在我开始使用Web服务.
因此,为了更好地理解如何解析XML,我开始尝试本教程：
http://www.anddev.org/novice-tutorials-f8/parsing-xml-from-the-net-using-the-saxparser-t353.html
使用本示例中使用的XML：
<outertag>
<innertag sampleattribute="innertagAttribute">
<mytag>anddev.org rulez =)</mytag>
<tagwithnumber thenumber="1337"/>
</innertag>
</outertag>
我知道它是如何工作的(我想),但是如果XML是这样的：
<outertag>
<innertag sampleattribute="innertagAttribute">
<mytag>anddev.org rulez =)</mytag>
<tagwithnumber thenumber="1337"/>
</innertag>
<innertag sampleattribute="innertagAttribute2">
<mytag>something</mytag>
<tagwithnumber thenumber="14214"/>
</innertag>
</outertag>
为了获得各种元素的数据,需要在应用程序的类中进行哪些更改？
我很高兴提出建议…
完整的源代码：
> ParseXML.java
包org.anddev.android.parsingxml;
导入java.net.URL;
导入javax.xml.parsers.SAXParser;
导入javax.xml.parsers.SAXParserFactory;
导入org.xml.sax.InputSource;
导入org.xml.sax.XMLReader;
导入android.app.Activity;
导入android.os.Bundle;
导入android.util.Log;
导入android.widget.TextView;
公共类ParsingXML扩展Activity {
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;
导入org.xml.sax.Attributes;
导入org.xml.sax.SAXException;
导入org.xml.sax.helpers.DefaultHandler;
公共类ExampleHandler扩展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;
公共类ParsedExampleDataSet {
私有字符串extractString = null;
私人诠释extractInt = 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;
}
}
解决方法:
问题解决了！
贝娄(Bellow)是包含有用信息的网站：
> 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
我最初的问题是如何为要从XML提取的数据定义类.在弄清楚应该如何做(回顾JAVA编程的基本概念)之后,我将ExampleHandler返回的数据类型更改为ArrayList<“您要返回的数据类”.
我在下面举一个例子：
>您要解析的XML示例：
<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>
因此,您应该在此处定义具有适当属性(字符串类型,模型,颜色,年份；),设置器和获取器的类“汽车”.
>我对XML的ExampleHandler的建议是：
公共类ExampleHandler扩展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));
}
}
}
之后,您可以使用以下方法在“活动”中获取解析的数据：
...
ArrayList<Car> ParsedData = myExampleHandler.getParsedData();
...
我希望这可以帮助别人.
注意：我没有完全像这样测试过,但与我的解决方案几乎相同,因此应该可以工作…
对不起,我英语不好…
标签：android,saxparser 来源： https://codeday.me/bug/20191009/1881171.html