I have a writeScore.class which is doing the following:
Get URL and than InputStream of a relative file score.xml
Start building new xml document by parsing through existing one
Append new record to the document builder
The last thing the program does should be to write the new document in a place of the old one. Sadly I can't find any way to use the relative path I already have. I've tried to use the use URLConnection and than .getOutputStream, but I get the protocol doesn't support output error. I also gave a try to OIUtils.copy(is, os) to convert InputStream into OutputStream but although there are no errors, for some reason the file doesn't change and the last modification date points to the last time I did it with direct file address. (I did a system wide search in case new file was created somewhere else, found nothing).
Here is simplified code using the URLConnection method:
public class writeScore {
public writeScore(Score NewScore, Interface obj) {
try {
// prepare file path
URL scoreUrl = new URL("file","localhost","save/score.xml");
InputStream is = scoreUrl.openStream();
final URLConnection scoreCon = scoreUrl.openConnection();
final OutputStream os = scoreCon.getOutputStream();
// build the document
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse(is);
// root element
Element root = doc.getDocumentElement();
Element rootElement = doc.getDocumentElement();
// add new save
/* removed for code cleaning */
// save source
DOMSource source = new DOMSource(doc);
// set up the transformer
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
// add properties of the output file
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
// save the file
StreamResult result = new StreamResult(os);
transformer.transform(source, result);
} // and catch all the exceptions
}
}
If need be I'm happy to change the way I input the file as well, as long I can have a relative path from Java/bin/game/writeScore.class to Java/save/score.xml where 'Java' is my project directory. But also once the game is package into a .jar and save is a folder outside of that jar.
Just use new File("name") that creates a file in the current working directory. With new File("../name") you create a file in the parent directory. You then need to wrap the file in a FileOutputStream.
But I would consinder using JAXB.unmarshal(file, clazz) for reading and JAXB.marshal(object, file) for writing. Just delete the old file before you write the new one. I never had troubles with updating resp. overwriting.
Here is how I did it, I removed the exception handling and logging. Pretty concise and generic, too.
public static <T> void writeXml(T obj, File f)
{
JAXB.marshal(obj, f);
}
Related
i am trying to add elements to xml document. Elements are added successfuly but problem is, that parser modifies original xml file in other places e.g it swaps namespace and id attributes or deletes duplicate namespace definitions. I need to get precisely the same document (same syntax, preserved whitespaces) only with specific elements added. I would greatly appreciate any suggestions. Here is my code:
public void appendTimestamp(String timestamp, String signedXMLFile, String timestampedXMLFile){
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try{
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(new File(signedXMLFile));
XPath xPath = XPathFactory.newInstance().newXPath();
NodeList list = (NodeList)xPath.evaluate("//*[local-name()='Signature']/*[local-name()='Object']/*[local-name()='QualifyingProperties']", doc, XPathConstants.NODESET);
if(list.getLength() != 1){
throw new Exception();
}
Node node = list.item(0);
Node unsignedProps = doc.createElement("xades:UnsignedProperties");
Node unsignedSignatureProps = doc.createElement("xzep:UnsignedSignatureProperties");
Node timestampNode = doc.createElement("xzep:SignatureTimeStamp");
timestampNode.appendChild(doc.createTextNode(timestamp));
unsignedSignatureProps.appendChild(timestampNode);
unsignedProps.appendChild(unsignedSignatureProps);
node.appendChild(unsignedProps);
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "no");
transformer.setOutputProperty(OutputKeys.METHOD, "xml");
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
DOMSource source = new DOMSource(doc);
StringWriter writer = new StringWriter();
StreamResult stringWriter = new StreamResult(writer);
transformer.transform(source, stringWriter);
writer.flush();
System.out.println(writer.toString());
}catch(Exception e){
e.printStackTrace();
}
}
The original xml file:
...
<ds:Object Id="objectIdVerificationObject" xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
...
Modified xml file:
...
<ds:Object xmlns:ds="http://www.w3.org/2000/09/xmldsig#" Id="objectIdVerificationObject">
...
If you use the dom model, then the whole xml file is read, then represented in the memory as the node tree and then saved to xml in a way determined by the writer. So it is almost impossible to preserve the original xml format as you don't have the control over it and for example whitespaces are not represented at all in the node tree.
You need to read partially the original xml and ouptut its content to the new file preserving what was read, then in the "right" place you need to add your new content adn then continue simple coapying of the original.
For example you could use the XMLStreamWriter and XMLStreamReader to achieve that as they offer "the low" level operations.
But probably it would be much easier to just copy the xml as the text line by one till you recognize the insertion point, then create new xml portion and append it as text and continue with copying.
I have to convert a text file with coordinates into a xml file. But the point of converting the text file into a xml file is so that the file size to be smaller. How can I reduce the size of my file?
public void writeXML() throws Exception
{
ArrayList<Frame> frameList = new ArrayList<Frame>();
frameList = readFile();
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder;
try
{
dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.newDocument();
// append stuff
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
//transformer.setOutputProperty(OutputKeys.INDENT, "yes");
DOMSource source = new DOMSource(doc);
StreamResult console = new StreamResult(System.out);
StreamResult file = new StreamResult(new File("file.xml"));
//transformer.transform(source, console);
transformer.transform(source, file);
System.out.println("DONE");
}
catch (Exception e)
{
e.printStackTrace();
}
}
But the point of converting the text file into a xml file is so that the file size to be smaller.
That is probably not achievable. XML is less dense than a typical text representation because properly designed XML adds a significant amount of "markup" to the file.
A file consisting of coordinates in an appropriately designed text form (e.g. CSV) will take less space than the same coordinates expressed in XML.
If you want "denser" files than a custom text format:
consider compressing the text file, or
consider using a binary representation instead of text.
If you are fixed on the idea of using XML, then the best way to reduce file size will be to compress it. Given that XML has a lot of redundancy in it (e.g. the markup), you should get significant compression.
I have this code that generates an XML file and saves to an external directory.
try //database structure
{
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
//test report elements, does not reflect the real database in the future
//mandatory/ username, location, caption, media, time(Actually, it's best if the server determines recieve time)
//optional/
//reportdata elements
Document doc = docBuilder.newDocument();
Element rootElement = doc.createElement("reportdata");
doc.appendChild(rootElement);
//username elements
Element username = doc.createElement("username");
username.appendChild(doc.createTextNode("testusername"));
rootElement.appendChild(username);
//Location ELEMENTS
//latitude elements
Element lat = doc.createElement("latitude");
lat.appendChild(doc.createTextNode(String.valueOf(latitude)));
rootElement.appendChild(lat);
//longitude
Element longi = doc.createElement("longitude");
longi.appendChild(doc.createTextNode(String.valueOf(longitude)));
rootElement.appendChild(longi);
//caption text elements
Element capt = doc.createElement("caption");
capt.appendChild(doc.createTextNode(captionText.getText().toString()));
rootElement.appendChild(capt);
//tag elements
String[] tagArr = new String[selectItems.size()];
tagArr = selectItems.toArray(tagArr);
Element tags = doc.createElement("tags");
rootElement.appendChild(tags);
int o = selectItems.size();
for(String s: tagArr) {
Element tagname = doc.createElement("tagname");
tagname.appendChild(doc.createTextNode(s));
tags.appendChild(tagname);
}
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
DOMSource source = new DOMSource(doc);
//StreamResult result = new StreamResult(System.out);
StreamResult result = new StreamResult(new File(android.os.Environment.getRootDirectory(), "upload_data.xml"));
transformer.transform(source, result);
Log.d("MESSAGE", result.toString());
After the creation of the XML file, this exception was raised
D/XML TransformerException﹕ java.io.FileNotFoundException: /system/upload_data.xml: open failed: EROFS (Read-only file system)
Any way to fix this?
... saves to an external directory
This is not quite right. You are trying to save it in the root system partition which is always read-only.
From javadoc of Environment.getRootDirectory():
Return root of the "system" partition holding the core Android OS. Always present and mounted read-only.
Solution : just save your file somewhere else :
StreamResult result = new StreamResult(new File(android.os.Environment.getExternalStorageDirectory(), "upload_data.xml"));
Note that :
you must ask the permission to write to the external storage :
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
External storage is not always available. The partition may not be mounted -yet- when you try to write on it. (just be careful)
first time using stack overflow, I'm now a student doing a project for analtics purpose, but the company store all the records into XML and I have to convert it and make a program as so to make it automated report send by email.
I'm using java to do XML parser and I'm now trying Apache common digester as other parser needs XSLT to do that, but iIwant a program that doesn't depends on XSLT because the company wants a system and sends a report like every 5 min of summary. So using XSLT may be quite slow as I saw some of the answer here. So may I know how to do that using digester or other methord, try to show some example the codes if possible, to make a conversion.
Here is the sample code I have build under digester:
public void run() throws IOException, SAXException {
Digester digester = new Digester();
// This method pushes this (SampleDigester) class to the Digesters
// object stack making its methods available to processing rules.
digester.push(this);
// This set of rules calls the addDataSource method and passes
// in five parameters to the method.
digester.addCallMethod("datasources/datasource", "addDataSource", 5);
digester.addCallParam("datasources/datasource/name", 0);
digester.addCallParam("datasources/datasource/driver", 1);
digester.addCallParam("datasources/datasource/url", 2);
digester.addCallParam("datasources/datasource/username", 3);
digester.addCallParam("datasources/datasource/password", 4);
File file = new File("C:\\Users\\1206432E\\Desktop\\datasource.xml");
// This method starts the parsing of the document.
//digester.parse("file:\\Users\\1206432E\\Desktop\\datasource.xml");
digester.parse(file);
}
Another one which is build using DOM to convert CSV to XML but still relies one XSLT file:
public static void main(String args[]) throws Exception {
File stylesheet = new File("C:\\Users\\1206432E\\Desktop\\Style.xsl");
File xmlSource = new File("C:\\Users\\1206432E\\Desktop\\data.xml");
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(xmlSource);
StreamSource stylesource = new StreamSource(stylesheet);
Transformer transformer = TransformerFactory.newInstance()
.newTransformer(stylesource);
Source source = new DOMSource(document);
Result outputTarget = new StreamResult(
new File("C:\\Users\\1206432E\\Desktop\\temp.csv"));
transformer.transform(source, outputTarget);
}
i am facing some problem for this following codes
try {
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
//root elements
Document doc = docBuilder.newDocument();
Element rootElement = doc.createElement("subcompany");
doc.appendChild(rootElement);
//id elements
Element id = doc.createElement("id");
id.appendChild(doc.createTextNode(subCompanyId != null ? subCompanyId : " "));
rootElement.appendChild(id);
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
DOMSource source = new DOMSource(doc);
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
String xmlPath = "/project/MallDirectory/mall";
//EDITED for File creation before writing.
boolean isFileCreated = new File(xmlPath, "subcompany.xml").createNewFile();
System.out.println(isFileCreated);
StreamResult result = new StreamResult(new File(xmlPath, "subcompany.xml"));
transformer.transform(source, result);
} catch (Exception ex) {
ex.printStackTrace();
}
After i run, i get this following error:
javax.xml.transform.TransformerException: java.io.FileNotFoundException: file:/project/MallDirectory/mall/subcompany.xml (No such file or directory)
It used to work on my other project, however not this time round. What exactly went wrong here ?
EDITED:
Here is the path that i am trying to write into. The file is created, but it is empty.
I managed to solve the problem.
Here is the Error:
javax.xml.transform.TransformerException: java.io.FileNotFoundException: file:/project/MallDirectory/mall/subcompany.xml (No such file or directory)
I am thinking maybe the transformer is trying to write the xml to this path 'file:/project/MallDirectory/mall/subcompany.xml'. I don't know how it happened, as i have specifically set the file path '/project/MallDirectory/mall/subcompany.xml', and does not prefixed with 'file:/'.
Therefore, i somehow managed to fix it by doing this:
...
//ERROR CODE:
//StreamResult result = new StreamResult(new File(xmlPath, "subcompany.xml"));
//
StreamResult result = new StreamResult(new File(xmlPath, "subcompany.xml").getPath());
transformer.transform(source, result);
...
The number of files that can be in open state at any point of time is specific to the OS (offcourse ,Can be configured) and you have reached the upper limit of that.Look in the code base of your application ,whehter you have some code that is trying to open a file but not closing the stream after its use.Check for such codes.
The directory path you have defined is incorrect. Take a look at the JavaDoc to determine which form of the directory path you need to get to your file location.
JavaDoc java.io.File
If "/project" is your project name then try "./MallDirectory/mall" else try "./project/MallDirectory/mall". Please observe the string carefully it contains dot in it.