Parsing of Android--xml files

Parsing methods: DOM, SAX, pull

1. DOM: Converting XML to a tree for traversal

Public void domparser ()  {    try {        1. Creating Documentbuilder instances       DocumentBuilder builder =  Documentbuilderfactory.newinstance (). Newdocumentbuilder ();        // 2. Create a document instance Document doc = builder.parse (file);// 3. Gets the root node of the XML file (persons) element  Element = doc.getdocumentelement ();// 4. Gets the list of child nodes of the root node (a list of person) nodelist personlist =  element.getelementsbytagname ("person");// todo// nodelist personlist =  Element.getchildnodes ();//This method does not// 5.  traverse all the person nodes for  (int i = 0; i  < personlist.getlength ();  i++)  {// 6. Gets a single person node element person =  ( Element)  personlist.item (i);// 7. Reads the property string id = person.getattribute ("id") of the person; System.out.println ("person   id:  " + id"// 8. Gets a list of child nodes for person nodelist childlist =  Person.getchildnodes ();// 9. Traverse the person child node for  (int j = 0; j <  Childlist.getlength ();  j++)  {        // 10. Accessing child nodes Node  child =  (Node)  childlist.item (j);if  (Child.getnodetype ()  == node.element_ node)  {//  If the child node is an element node// 11. Gets the element name String name = child.getnodename ();if  (" Name ". Equals (name))  {//  get Person namesystem.out.println (" Name:  "         + child.getfirstchild (). Getnodevalue ());}  else if  ("Age". Equals (name))  {//  get Person agesystem.out.println ("Ages:"          + child.getfirstchild (). Getnodevalue ());}}}}  catch  (parserconfigurationexception e) &NBSP;{//&NBSP;TODO&NBSP;AUTO-GENERATED&NBSP;CATCH&NBSp;blocke.printstacktrace ();}  catch  (saxexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}  catch  (ioexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}}

2.SAX: Traverse tags from top to bottom

 1. Creating a handler class, inheriting defaulthandlerclass saxhandler extends defaulthandler {/**  Previous node name  */private String tag;//  need to override five methods:// 1.startdocument (): Preprocessing// 2 when starting a document. Enddocument (): Finishing the document when you are finished// 3.startelement (): The start tag is called to call the method// 4.endelement (): Call the method// 5 when the closing tag is encountered. Characters (): Content public void startdocument ()  throws saxexception {system.out.println (" Call the Startdocument () method ");} Public void enddocument ()  throws saxexception {system.out.println ("Call EndDocument () method") );}   Read the property of the tag in this method Public void startelement (string uri, string localname,  string qname,attributes attributes)  throws saxexception {system.out.println (" Call the Startelement () method "+" LocalName: "+localname+" QName: "+qname";if  ("person". Equals (QName))  { System.out.println ("person:       "); System.out.println ("     id:&nbsP; "  + attributes.getvalue ("id"));} Tag = qname;} Public void endelement (String uri, string localname, string qname) throws  saxexception {system.out.println ("Call EndElement () method");}   reads the label content//  calls Public void characters each time it starts to end the tag (char[] ch, int start,  Int length) Throws saxexception {system.out.println ("Call characters () method"); String data = new string (ch, start, length);if  ("Name". Equals (tag))  { System.out.println ("name: "  + data);  else if  ("Age". Equals (Tag))  {system.out.println ("age: "  + data);}}  2.sax  parsing Public void saxparser ()  {try {//2.1 Creating a parser Javax.xml.parsers.SAXParser  parser = saxparserfactory.newinstance (). Newsaxparser ();//2.2 Create processor saxhandler handler  = new saxhandler ();//2.3 create file input stream FILEINPUTSTREAM FIS = NEW&NBsp FileInputStream (file);//2.4 parsing file Parser.parse (File, handler);}  catch  (filenotfoundexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}  catch  (parserconfigurationexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}  catch  (saxexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}  catch  (ioexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}}

3.Pull: Similar to sax, with more applications in Android development

Public static void xmlpullparser (Inputstream is)  {try {// 1. Gets the input stream// 2. Gets the parser xmlpullparser parser = xml.newpullparser ();p arser.setinput (is,  "Utf-8");// 3. Gets the event type Int eventtype = parser.geteventtype ();// 4. Traversing node while (eventtype !=  xmlpullparser.end_document) {switch  (eventtype)  {case xmlpullparser.start_document://file open break; case xmlpullparser.start_tag://tag starts//4.1 gets the node name String name = parser.getname (); Name.equals ("person")) {//4.2  Gets the node attribute value string id = parser.getattributevalue (0);} Else if (name.equals ("name")) {//4.3  gets the next text value System.out.println ("name: " + parser.nexttext ());} Else if (Name.equals ("Age")) {System.out.println ("age: " + parser.nexttext ());} break;case xmlpullparser.end_tag://tag end Break;default:break;} Eventtype = parser.next ();} Is.close ();}  catch  (filenotfoundexception e)  {//&NBSp Todo auto-generated catch blocke.printstacktrace ();}  catch  (xmlpullparserexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}  catch  (ioexception e)  {// TODO Auto-generated catch  Blocke.printstacktrace ();}}

This article is from the "Androidcamera Summary" blog, please be sure to keep this source http://7183397.blog.51cto.com/7173397/1606124

Parsing of Android--xml files