Dom4j parsing XML

// Read content
Public void read () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

Element root = Document. getrootelement ();
Element book = (element) root. Elements ("book"). Get (1); // get the second book in XML
String value = book. element ("name"). gettext ();
}
// Read attributes
Public void readattr () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

Element root = Document. getrootelement ();
Element book = (element) root. Elements ("book"). Get (1); // get the second book in XML
String value = book. element ("name"). attributevalue ("name ");
}
// Add
Public void add () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

Element book = Document. getrootelement (). element ("book ");
Book. addelement ("price"). settext ("209 ");

Xmlwriter writer = new xmlwriter (New outputstreamwriter (New fileoutputstream ("src/book. xml"), "UTF-8 "));
Writer. Write (document );
Writer. Close ();
}
// Add an element to a specified position
Public void Add2 () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");
Element book = Document. getrootelement (). element ("book ");
List list = book. Elements ();

Element element = incluenthelper. createelement ("price ");
Element. settext ("309 ");

List. Add (2, element );
Outputformat format = outputformat. createprettyprint ();
Format. setencoding ("UTF-8 ");

Xmlwriter writer = new xmlwriter (New fileoutputstream ("src/book. xml"), format );
Writer. Write (document );
Writer. Close ();
}
// Delete
Public void Delete () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

Element price = Document. getrootelement (). element ("book"). element ("price ");
Price. getparent (). Remove (price );
Outputformat format = outputformat. createprettyprint ();
Format. setencoding ("UTF-8 ");

Xmlwriter writer = new xmlwriter (New fileoutputstream ("src/book. xml"), format );
Writer. Write (document );
Writer. Close ();
}
// Update
Public void Update () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

Element book = (element) document. getrootelement (). Elements ("book"). Get (1 );
Book. element ("author"). settext ("or dawn ");
Outputformat format = outputformat. createprettyprint ();
Format. setencoding ("UTF-8 ");

Xmlwriter writer = new xmlwriter (New fileoutputstream ("src/book. xml"), format );
Writer. Write (document );
Writer. Close ();
}
// Use XPath to extract data from XML documents
Public void extract () throws exception {
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/book. xml ");

String value = Document. selectsinglenode ("author"). gettext (); // obtain the name of the first author.
}
// Search for usernames and passwords that match the user in user. xml.
@ Test
Public void extract2 () throws exception {
String username = "AAA ";
String Password = "123 ";
Saxreader reader = new saxreader ();
Document document = reader. Read ("src/users. xml ");
Node node = Document. selectsinglenode ("// user [@ username = '" + username + "' and @ Password = '" + password + "']");
If (node = NULL ){
System. Out. println ("Login Failed! ");
} Else {
System. Out. println ("Login successful! ");
}
}