Can't access file in .jar via URL - java

I need to access a file inside the currently executed .jar using a URL.
URL url = BlockConverter.class.getResource("/test.txt");
System.out.println(url.toString());
InputStream is = url.openStream();
This is what I did.
The output is:
jar:file:/C:/Users/User/Desktop/SERVER/plugins/MyJar.jar!/test.txt
My InputStream always ends up throwing an IOException when being initialized, even though the URL is being output correctly.
So how is that possible?
Why can't I open the stream?
EDIT:
Also, please don't answer with "use getResourceAsStream", since it uses the same kind of code:
public InputStream getResourceAsStream(String name) {
URL url = getResource(name);
try {
return url != null ? url.openStream() : null;
} catch (IOException e) {
return null;
}
}

I would open it as a stream directly e.g.
InputStream is = BlockConverter.class.getResourceAsStream("/test.txt");
The above method is the way I normally access resources within a jar (it will open the resource regardless of it being packaged within a jar, or simply as an unpackaged deployment, note)

Related

Properties file not loading and updating for relative path but working fine for absolute path

I am trying to access a properties file from the src/main/resources folder but when I try to load the file using a relative path it is not getting updated. But it is working fine for an absolute path.
I need the dynamic web project to work across all platforms.
public static void loadUsers() {
try(
FileInputStream in = new FileInputStream("C:\\Users\\SohamGuha\\Documents\\work-coding\\work-coding\\src\\main\\resources\\users.properties")) {
// write code to load all the users from the property file
// FileInputStream in = new FileInputStream("classpath:users.properties");
users.load(in);
System.out.println(users);
in.close();
}
catch(Exception e){
e.printStackTrace();
}
First of all you are using Spring, at least that is what the tags at the bottom say. Secondly C:\\Users\\SohamGuha\\Documents\\work-coding\\work-coding\\src\\main\\resources\\users.properties is the root of your classpath. Instead of loading a File use the Spring resource abstraction.
As this is part of the classpath you can simply use the ClassPathResource to obtain a proper InputStream. This will work regardless of which environment you are in.
try( InputStream in = new ClassPathResource("users.properties").getInputStream()) {
//write code to load all the users from the property file
//FileInputStream in = new FileInputStream("classpath:users.properties");
users.load(in);
System.out.println(users);
} catch(Exception e){
e.printStackTrace();
}
NOTE: you are already using a try with resources so you don't need to close the InputStream that is already handled for you.
Changing things inside your application simply won't work, as this would mean you could change resources (read classes) in your jar which would be quite a security risk! If you want something to be changable you will have to make it a file outside of the classpath and directly on the file-system.
Try the following code
import java.io.FileInputStream;
import java.io.IOException;
public class LoadUsers {
public static void main(String[] args) throws IOException {
try(FileInputStream fis=new FileInputStream("src/main/resources/users.properties")){
Properties users=new Properties();
users.load(fis);
System.out.println(users);
}catch(IOException ioe) {
ioe.printStackTrace();
}
}
}

Can not load properties file from the web-inf folder in Websphere 8.5 server

I am trying to load a properties file from WEb-INF folder in my web application , which is running on Websphere 8.5 . I am using below code to load the file from the location
public class Init {
private final String WEB_INF_DIR_NAME="WEB-INF";
private String web_inf_path;
private final Properties APP_PROPERTIES =null;
InputStream inputStream = null;
public String getWebInfPath() throws IOException {
if (web_inf_path == null) {
web_inf_path = URLDecoder.decode(Init.class.getProtectionDomain().getCodeSource().getLocation().getPath(), "UTF8");
web_inf_path=web_inf_path.substring(0,web_inf_path.lastIndexOf(WEB_INF_DIR_NAME)+WEB_INF_DIR_NAME.length()).substring(1);
}
inputStream = Init.class.getResourceAsStream("/config/localhost/accountservice.properties");
// inputStream = this.getClass().getClassLoader().getResourceAsStream("/config/localhost/accountservice.properties");
if (inputStream != null) {
APP_PROPERTIES.load(inputStream);
}
System.out.println(APP_PROPERTIES.getProperty(AccountServiceDataAccessConstants.INET_LIBRARY_NAME)); // Here i am getting NULL
return web_inf_path;
}
}
I have also tried using servlet context , but its also giving me NULL. I have tried all possible ways to solve it but unfortunately i am not able to do it. I am also giving my folder structure.
Please excuse me if this is a silly question , but i am not really getting any idea about it.
Usually, everything in WebContent is placed in the root of your WAR file. So instead of
inputStream = Init.class.getResourceAsStream("/config/localhost/accountservice.properties");
It would be
inputStream = Init.class.getResourceAsStream("/WEB-INF/config/localhost/accountservice.properties");
The root of the WAR has WEB-INF in it, and then you can descend into your folder structure as normal.

How to get files from resources folder. Spring Framework

I'm trying to unmarshal my xml file:
public Object convertFromXMLToObject(String xmlfile) throws IOException {
FileInputStream is = null;
File file = new File(String.valueOf(this.getClass().getResource("xmlToParse/companies.xml")));
try {
is = new FileInputStream(file);
return getUnmarshaller().unmarshal(new StreamSource(is));
} finally {
if (is != null) {
is.close();
}
}
}
But I get this errors:
java.io.FileNotFoundException: null (No such file or directory)
Here is my structure:
Why I can't get files from resources folder? Thanks.
Update.
After refactoring,
URL url = this.getClass().getResource("/xmlToParse/companies.xml");
File file = new File(url.getPath());
I can see an error more clearly:
java.io.FileNotFoundException: /content/ROOT.war/WEB-INF/classes/xmlToParse/companies.xml (No such file or directory)
It tries to find WEB-INF/classes/
I have added folder there, but still get this error :(
I had the same problem trying to load some XML files into my test classes. If you use Spring, as one can suggest from your question, the easiest way is to use org.springframework.core.io.Resource - the one Raphael Roth already mentioned.
The code is really straight forward. Just declare a field of the type org.springframework.core.io.Resource and annotate it with org.springframework.beans.factory.annotation.Value - like that:
#Value(value = "classpath:xmlToParse/companies.xml")
private Resource companiesXml;
To obtain the needed InputStream, just call
companiesXml.getInputStream()
and you should be okay :)
But forgive me, I have to ask one thing: Why do you want to implement a XML parser with the help of Spring? There are plenty build in :) E.g. for web services there are very good solutions that marshall your XMLs into Java Objects and back...
ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource("fileName").getFile());
you are suppose to give an absolute path (so add a loading ´/´, where resource-folder is the root-folder):
public Object convertFromXMLToObject(String xmlfile) throws IOException {
FileInputStream is = null;
File file = new File(String.valueOf(this.getClass().getResource("/xmlToParse/companies.xml")));
try {
is = new FileInputStream(file);
return getUnmarshaller().unmarshal(new StreamSource(is));
} finally {
if (is != null) {
is.close();
}
}
}

Generating pdf with wkhtmltopdf and download the pdf

I am working in a old project.The project is in Spring MVC .In the project I have to generate a pdf file from a jsp page and store in a location and download that file. For that I am using wkhtmltopdf tool to convert the one specific jsp page into pdf format. Using wkhtmltopdf sometime works fine, it generate the pdf in specific location, but sometime it require more time. Also when I am trying to download the file from specific location , sometime it download a 0KB size file or sometime the downloaded file can't be open (with some size) but sometime download perfectly. If I check the file at define location, it exist and open normally.
Here is my code in controller class.
#RequestMapping(value="/dwn.htm",method=RequestMethod.GET)
public void dwAppFm(HttpSession session,HttpServletRequest request,HttpServletResponse response,#RequestParam String id) throws IOException,InterruptedException
{
final int BUFFER_SIZES=4096;
ServletContext context=request.getServletContext();
String savePath="/tmp/";//PDF file Generate Path
String fileName="PDFFileName"; //Pdf file name
FileInputStream inputStream=null;
BufferedInputStream bufferedInputStream=null;
OutputStream outputStream=null;
printApp(id,fileName);
Thread.sleep(1000);
printApp(id,fileName);
File download=new File(savePath+fileName+".pdf");
while(!download.canRead())
{
Thread.sleep(1000);
printApp(id,fileName);
download=new File(savePath+fileName+".pdf");
}
if(download.canRead()){//if the file can read
try{
Thread.sleep(1000);
inputStream=new FileInputStream(download);
bufferedInputStream=new BufferedInputStream(inputStream);
String mimeType = context.getMimeType(savePath+fileName+".pdf");
if (mimeType == null) {
mimeType = "application/octet-stream";
}
System.out.println("MIME type: " + mimeType);
response.setContentType(mimeType);
response.setContentLength((int)download.length());
String headerKey="Content-Disposition";
String headerValue=String.format("attachment;filename=\"%s\"", download.getName());
response.setHeader(headerKey, headerValue);
outputStream=response.getOutputStream();
byte[] buffer=new byte[BUFFER_SIZES];
int bytesRead=-1;
while ((bytesRead = bufferedInputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
}catch(Exception e)
{
e.printStackTrace();
}
finally
{
try{
if(inputStream!=null)inputStream.close();
if(bufferedInputStream!=null)bufferedInputStream.close();
if(outputStream!=null)outputStream.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
}
public void printApp(String id,String fileName)
{
try{
String urlPath="http://localhost:8080/proj";
urlPath+="/genApp.htm?id="+id;//generate url to execute wkhtmltopdf
String wxpath="/home/exm/wkhtmltopdf";//the path where wkhtmltopdf located
String save="/tmp/"+fileName+".pdf";//File save Pathname
Process process=null;
process=Runtime.getRuntime().exec(wxpath+" "+urlPath+" "+save);
}catch(Exception e)
{}
}
#RequestMapping(value="/genApp.htm",method=RequestMethod.GET)
public String getApplicationPDF(HttpServletRequest request,HttpSession session,#RequestParam String id)
{
UDets uDets=uService.getAllById(Long.parseLong(id));//Methods to get details
request.setAttribute("uDets",uDets );
return "makeApp";//Name of the jsp page
}
In my code I have use Thread.sleep(1000) and printApp(id,fileName) method three times , since sometime wkhtmltopdf fail to generate pdf in certain time and then probability of downloading 0KB file is more. I haven't share the jsp page since the jsp page contain simple jsp page code of lots of line (the size of the generated pdf file is two page).
So the problem is what should I change in my code so that the pdf file generated and download without a failure also in heavy load in server.
If there is any best procedure or idea please share.
I don't like to use itext, since the jsp page contain complex design. Any advise is also appreciable and also thanks in advance.
I would say that your code is flawed not just a little but big time. You are checking if a file can be read, if not you start again a proces writing to the same file (at least twice). At some time you will endup with multiple processes trying to write to the same file, resulting in strange behavior.
I would refactor the printApp method to return the Process it created. Then call waitFor on that process. If it returns 0 and doesn't get interrupted it completed successfully and you should be able to download the file.
#RequestMapping(value="/dwn.htm",method=RequestMethod.GET)
public void dwAppFm(HttpSession session,HttpServletRequest request,HttpServletResponse response,#RequestParam String id) throws IOException,InterruptedException
{
String savePath="/tmp/";//PDF file Generate Path
String fileName="PDFFileName.pdf"; //Pdf file name
File download = new File(savePath, fileName);
try {
Process process = printApp(id, download.getPath());
int status = process.waitFor();
if (status == 0) {
response.setContentType("application/pdf");
response.setContentLength((int)download.length());
String headerKey="Content-Disposition";
String headerValue=String.format("attachment;filename=\"%s\"", download.getName());
StreamUtils.copy(new FileInputStream(download), response.getOutputStream())
} else {
// do something if it fails.
}
} catch (IOException ioe) {
// Do something to handle exception
} catch (InterruptedException ie) {
// Do something to handle exception
}
}
}
public Process printApp(String id, String pdf) throws IOException {
String urlPath="http://localhost:8080/proj";
urlPath+="/genApp.htm?id="+id;//generate url to execute wkhtmltopdf
String wxpath="/home/exm/wkhtmltopdf";//the path where wkhtmltopdf located
String command = wxpath+" "+urlPath+" "+pdf;
return Runtime.getRuntime().exec(command);
}
Something like the code above should to the trick.

open a file in a tomcat webapplication

i want to open a file and return its content. Although it is in the same directory like the class that wants to open the file, the file can't be found. Would be cool if you could help me solving the problem.
Here is the code:
#GET #Produces("text/html") #Path("/{partNO}/") #Consumes("text/html")
public String getPartNoResponseHTML(#PathParam("partNO") String parID) throws WebApplicationException {
PartNoTemplate partNo = getPartNoResponse(parID);
String result = "";
try {
result = readFile(PART_NO_TEMPLATE_FILE);
} catch (FileNotFoundException e) {
e.printStackTrace(System.out);
return e.getMessage() + e.toString();
// throw new WebApplicationException(Response.Status.NOT_FOUND);
} finally {
result = result.replace("{partNO}", parID);
result = result.replace("{inputFormat}", partNo.getFormat().toString());
}
return result;
}
I guess it can't find the file, because its running on tomcat. I'm also using Jersey and JAX-RS. Thank you for your help,
Maxi
If the file is inside the application WAR (or in a jar) you can try by using
InputStream input = servletContext.getClass().getClassLoader().getResourceAsStream("my_filename.txt");
Your problem is similar (I think) with How can I read file from classes directory in my WAR?
Try to get the path of the file from ServletContext.
ServletContext context = //Get the servlet context
In JAX-RS to get servlet context use this:
#javax.ws.rs.core.Context
ServletContext context;
Then get the file from your web application:
File file = new File(context.getRealPath("/someFolder/myFile.txt"));
You don't post the code that actually tries to read the file, but assuming the file is in the classpath (as you mention it's in the same directory as the class) then you can do:
InputStream in = this.getClass().getResourceAsStream("/SomeTextFile.txt");
See here

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