使用javaxmlapi将xml文档保存到文件中
本文关键字：存到文件 文档 xml javaxmlapi 使用 | 更新日期: 2023-09-27 18:23:51
我被困在这个级别（代码段中Java和C#的不可编译混合）：
...
//then write results out to a file, which can then be used by XPF Application
Document photosDoc = new Document();
Element photosElement = new Element("photos", from pi in photos
select new XElement("photo",
new XElement("url", pi.PhotoUrl(false)),
new XElement("title", pi.Title))
);
photosDoc.Add(photosElement);
photosDoc.Save("C:''photos.xml");
我不知道如何转换这部分代码以将结果写入文件。我想将结果保存到一个xml文件中。
有什么帮助吗？
我在尝试将C#代码转换为java代码时偶然发现了这个问题：
using System;
using System.Collections.Generic;
using System.Text;
System.Query;
using System.Xml.XLinq;
using System.Data.DLinq;
public class RSSImageFeed
{
private const string FLICKR_API_KEY = "c705bfbf75e8d40f584c8a946cf0834c";
private const string MOST_RECENT = "http://www.flickr.com/services/rest/?method=flickr.photos.getRecent&api_key=" + FLICKR_API_KEY;
private const string INTERESTING = "http://www.flickr.com/services/rest/?method=flickr.interestingness.getList&api_key=" + FLICKR_API_KEY;
private const string ENTER_TAG = "http://www.flickr.com/services/rest/?method=flickr.photos.search&api_key=" + FLICKR_API_KEY + "&tags=";
private string url = MOST_RECENT;
private int pageIndex = 0;
private int columns = 5;
private int rows = 2;
private bool prevAvail = false;
private bool nextAvail = false;
public RSSImageFeed()
{
}
public bool IsPrevAvail
{
get { return prevAvail; }
}
public bool IsNextAvail
{
get { return nextAvail; }
}
public int PageIndex
{
set { pageIndex = value; }
get { return pageIndex; }
}
public bool LoadPictures(string searchType, string searchWord)
{
switch (searchType)
{
case "Most Recent":
this.url=MOST_RECENT;
break;
case "Interesting":
this.url=INTERESTING;
break;
case "By Search Word":
this.url = ENTER_TAG + searchWord;
break;
default :
this.url = MOST_RECENT;
break;
}
try
{
var xraw = XElement.Load(url);
var xroot = XElement.Parse(xraw.Xml);
//select the RSS data from Flickr, and use standard LINQ projection
//to store it within a new PhotoInfo which is an object of my own making
var photos = (from photo in xroot.Element("photos").Elements("photo")
select new PhotoInfo
{
Id = (string)photo.Attribute("id"),
Owner = (string)photo.Attribute("owner"),
Title = (string)photo.Attribute("title"),
Secret = (string)photo.Attribute("secret"),
Server = (string)photo.Attribute("server"),
Farm = (string)photo.Attribute("Farm"),
}).Skip(pageIndex * columns * rows).Take(columns * rows);
//set the allowable next/prev states
int count = photos.Count();
if (pageIndex == 0)
{
this.prevAvail = false;
this.nextAvail = true;
}
else
{
this.prevAvail = true;
}
//see if there are less photos than sum(Columns * Rows) if there are less
//cant allow next operation
if (count < columns * rows)
{
this.nextAvail = false;
}
//then write results out to a file, which can then be used by XPF Application
XDocument photosDoc = new XDocument();
XElement photosElement = new XElement("photos", from pi in photos
select new XElement("photo",
new XElement("url", pi.PhotoUrl(false)),
new XElement("title", pi.Title))
);
photosDoc.Add(photosElement);
photosDoc.Save(@"c:'photos.xml");
return true;
}
catch (Exception ex)
{
return false;
}
}
}
以下是我将上面的C#代码转换为java代码的尝试：
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class FlickrFeed {
private String FLICKR_API_KEY = "204e5627ea6626101221a5c7b4b0dd3a";
private String MOST_RECENT = "http://www.flickr.com/services/rest/?method=flickr.photos.getRecent&api_key=" + FLICKR_API_KEY;
private String INTERESTING = "http://www.flickr.com/services/rest/?method=flickr.interestingness.getList&api_key=" + FLICKR_API_KEY;
private String ENTER_TAG = "http://www.flickr.com/services/rest/?method=flickr.photos.search&api_key=" + FLICKR_API_KEY + "&tags=";
private String url = MOST_RECENT;
private int pageIndex = 0;
private int columns = 5;
private int rows = 2;
private boolean prevAvail = false;
private boolean nextAvail = false;
public enum SearchType
{
Most_Recent, Interesting, By_Search_Word
}
public FlickrFeed()
{
}
public boolean IsPrevAvail()
{
return prevAvail;
}
public boolean IsNextAvail()
{
return nextAvail;
}
public int PageIndex(int value)
{
pageIndex = value;
return pageIndex;
}
public boolean LoadPictures( String searchWord)
{
SearchType searchType = SearchType.By_Search_Word;
switch (searchType)
{
case Most_Recent:
this.url=MOST_RECENT;
break;
case Interesting:
this.url=INTERESTING;
break;
case By_Search_Word:
this.url = ENTER_TAG + searchWord;
break;
default :
this.url = MOST_RECENT;
break;
}
try
{
// var xraw = XElement.Load(url);
// var xroot = XElement.Parse(xraw.Xml);
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
URL Url = new URL(url);
Document doc = builder.parse(Url.openStream());
NodeList nodes = null;
Element element = null;
//select the RSS data from Flickr, and store it within a new PhotoInfo which is an object of my own making
nodes = doc.getElementsByTagName("photo");
for (int i = 0; i < nodes.getLength(); i++) {
element = (Element) nodes.item(i);
String Id = (String)element.getAttribute("id");
System.out.println("id:="+Id);
String Owner=(String)element.getAttribute("owner");
System.out.println("Owner:="+Owner);
String Title = (String)element.getAttribute("title");
System.out.println("Title:="+Title);
String Secret= (String)element.getAttribute("secret");
System.out.println("Secret:="+Secret);
String Server= (String)element.getAttribute("server");
System.out.println("Server:="+Server);
String Farm= (String)element.getAttribute("farm");
System.out.println("Farm:="+Farm);
System.out.println("ok: " + nodes.getLength());
}
/* photos = (from photo in xroot.Element("photos").Elements("photo")
select new PhotoInfo
{
Id = (string)photo.Attribute("id"),
Owner = (string)photo.Attribute("owner"),
Title = (string)photo.Attribute("title"),
Secret = (string)photo.Attribute("secret"),
Server = (string)photo.Attribute("server"),
Farm = (string)photo.Attribute("Farm"),
}).Skip(pageIndex * columns * rows).Take(columns * rows);*/
//set the allowable next/prev states
// int count = photos.Count();
int count = nodes.getLength();
if (pageIndex == 0)
{
this.prevAvail = false;
this.nextAvail = true;
}
else
{
this.prevAvail = true;
//see if there are less photos than sum(Columns * Rows) if there are less
//cant allow next operation
if (count < columns * rows)
{
this.nextAvail = false;
}
//then write results out to a file, which can then be used by XPF Application
Document photosDoc = new Document();
Element photosElement = new Element("photos", from pi in photos
select new XElement("photo",
new XElement("url", pi.PhotoUrl(false)),
new XElement("title", pi.Title))
);
photosDoc.Add(photosElement);
photosDoc.Save("C:''photos.xml");
return true;
}
catch (Exception ex)
{
return false;
}
/**
* Methode permettant de retourner ce que contient un noeud
* @param _node le noeud principal
* @param _path suite des noms des noeud sans espace separés par des "|"
* @return un string contenant la valeur du noeud voulu
*/
}
public String readNode(Node _node, String _path) {
String[] paths = _path.split("''|");
Node node = null;
if (paths != null && paths.length > 0) {
node = _node;
for (int i = 0; i < paths.length; i++) {
node = getChildByName(node, paths[i].trim());
}
}
if (node != null) {
return node.getTextContent();
} else {
return "";
}
}
/**
* renvoye le nom d'un noeud fils a partir de son nom
* @param _node noeud pricipal
* @param _name nom du noeud fils
* @return le noeud fils
*/
public Node getChildByName(Node _node, String _name) {
if (_node == null) {
return null;
}
NodeList listChild = _node.getChildNodes();
if (listChild != null) {
for (int i = 0; i < listChild.getLength(); i++) {
Node child = listChild.item(i);
if (child != null) {
if ((child.getNodeName() != null && (_name.equals(child.getNodeName()))) || (child.getLocalName() != null && (_name.equals(child.getLocalName())))) {
return child;
}
}
}
}
return null;
}
public static void main(String[] args) {
FlickrFeed f= new FlickrFeed();
f.LoadPictures("upcoming:event");
}
}
我从未见过C#->Java转换工具。语法很简单，但框架却大不相同。即使有一个工具，我也强烈建议不要使用。这不是捷径，你最终得到的是不可读的代码，也不会利用目标语言。我认为重写代码将是最好的方案。
对于Linq部分，请尝试查看Quaere。小心，这个项目还处于早期阶段。
您的代码看起来很像在Java/C#中进行XML转换。我会使用XSL来进行转换。我认为这会使代码更干净。
特别是这部分：
Element photosElement = new Element("photos", from pi in photos
select new XElement("photo",
new XElement("url", pi.PhotoUrl(false)),
new XElement("title", pi.Title))
);
这正是XSL的初衷。