Develop Reference

Download multiple files(stored in a database) in a zip in java

How to download multiple files in a zip folder. I am using spring-boot and documents are saved in MongoDB using GridFS.
I was trying to download using FileSystemResource which takes File as an argument taking reference from https://simplesolution.dev/spring-boot-download-multiple-files-as-zip-file/
I tried to get download a resource from mongodb using below line of code and convert it into File object using
gridFsTemplate.getResource(GridFsFile).getFile();
I but it throws an error saying
GridFS resource can not be resolved to an absolute file path.

I have done using ByteArrayResource:
public void downloadZipFile(HttpServletResponse response, List<String> listOfDocIds) {
response.setContentType("application/zip");
response.setHeader("Content-Disposition", "attachment; filename=download.zip");
List<FileResponse> listOfFiles = myService.bulkDownload(listOfDocIds);// This call will fetch docs in the form of byte[] based on docIds.
try(ZipOutputStream zipOutputStream = new ZipOutputStream(response.getOutputStream())) {
for(FileResponse fileName : listOfFiles) {
ByteArrayResource fileSystemResource = new ByteArrayResource(fileName.getFileAsBytes);
ZipEntry zipEntry = new ZipEntry(fileName.getFileName());
zipEntry.setSize(fileSystemResource.contentLength());
zipEntry.setTime(System.currentTimeMillis());
zipOutputStream.putNextEntry(zipEntry);
StreamUtils.copy(fileSystemResource.getInputStream(), zipOutputStream);
zipOutputStream.closeEntry();
}
zipOutputStream.finish();
} catch (IOException e) {
logger.error(e.getMessage(), e);
}
}
class FileResponse{
private String fileName;
private byte[] fileAsBytes;
// setter and getters
}

Unable to attach file to issue in jira via rest api Java

I want to attach multiple files to issue. I'm able to create issue successfully however i am facing problem in attaching documents after creating issue. I have referred to this link SOLVED: attach a file using REST from scriptrunner
I am getting 404 error even though issue exists and also user has all the permissions.
File fileToUpload = new File("D:\\dummy.txt");
InputStream in = null;
try {
in = new FileInputStream(fileToUpload);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
HttpResponse < String > response3 = Unirest
.post("https://.../rest/api/2/issue/test-85/attachments")
.basicAuth(username, password).field("file", in , "dummy.txt")
.asString();
System.out.println(response3.getStatus());
here test-85 is a issueKey value.
And i am using open-unirest-java-3.3.06.jar. Is the way i am attaching documents is correct?

I am not sure how open-unirest manages its fields, maybe it tries to put them as json field, rather than post content.
I've been using Rcarz's Jira client. It's a little bit outdated but it still works.
Maybe looking at its code will help you, or you can just use it directly.
The Issue class:
public JSON addAttachment(File file) throws JiraException {
try {
return restclient.post(getRestUri(key) + "/attachments", file);
} catch (Exception ex) {
throw new JiraException("Failed add attachment to issue " + key, ex);
}
}
And in RestClient class:
import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
public JSON post(String path, File file) throws RestException, IOException, URISyntaxException {
return request(new HttpPost(buildURI(path)), file);
}
private JSON request(HttpEntityEnclosingRequestBase req, File file) throws RestException, IOException {
if (file != null) {
File fileUpload = file;
req.setHeader("X-Atlassian-Token", "nocheck");
MultipartEntity ent = new MultipartEntity();
ent.addPart("file", new FileBody(fileUpload));
req.setEntity(ent);
}
return request(req);
}
So I'm not sure why you're getting a 404, Jira is sometime fuzzy and not really clear about its error, try printing the full error, or checking Jira's log if you can. Maybe it's just the "X-Atlassian-Token", "nocheck", try adding it.

Can not read file when run within jar file

I have an akka http service. I simply return the api documentation for a get request. The documentation is in html file.
It all works fine when run within the IDE. When I package it as a jar I get error 'resource not found'. I am not sure why it can not read the html file when hosted in a jar and works fine when in IDE.
Here is the code for the route.
private Route topLevelRoute() {
return pathEndOrSingleSlash(() -> getFromResource("asciidoc/html/api.html"));
}
The files are located in resource path.

I have got this working now.
I am doing this.
private Route topLevelRoute() {
try {
InputStreamReader inputStreamReader = new InputStreamReader(getClass().getResourceAsStream("/asciidoc/html/api.html"));
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
//Get the stream input into string builder
reader.lines().forEach(s -> strBuild.append(s));
inputStreamReader.close();
bufferedReader.close();
//pass the string builder as string with contenttype set to html
complete(HttpEntities.create(ContentTypes.TEXT_HTML_UTF8, strBuild.toString()))
} catch (Exception ex) {
//Catch any exception here
}
}

Reading From Config File Outside Jar Java

Currently I am trying to read my config file from root of project directory, in order to make this actual configuration I want to move this to external location and then read from there.
Adding a complete path in following code throws out error :
package CopyEJ;
import java.util.Properties;
public class Config
{
Properties configFile;
public Config()
{
configFile = new java.util.Properties();
try {
// configFile.load(this.getClass().getClassLoader().getResourceAsStream("CopyEJ/config.properties"));
Error Statement ** configFile.load(this.getClass().getClassLoader().getResourceAsStream("C://EJ_Service//config.properties"));
}catch(Exception eta){
eta.printStackTrace();
}
}
public String getProperty(String key)
{
String value = this.configFile.getProperty(key);
return value;
}
}
Here's the error:
java.lang.NullPointerException
at java.util.Properties$LineReader.readLine(Properties.java:365)
at java.util.Properties.load(Properties.java:293)
at CopyEJ.Config.<init>(Config.java:13)
at CopyEJ.CopyEJ.main(CopyEJ.java:22)
Exception in thread "main" java.lang.NullPointerException
at java.io.File.<init>(File.java:194)
at CopyEJ.CopyEJ.main(CopyEJ.java:48)
How can I fix this ?

The purpose of method getResourceAsStream is to open stream on some file, which exists inside your jar. If you know exact location of particular file, just open new FileInputStream.
I.e. your code should look like:
try (FileInputStream fis = new FileInputStream("C://EJ_Service//config.properties")) {
configFile.load(fis);
} catch(Exception eta){
eta.printStackTrace();
}

This line requires your config.properties to be in the java CLASSPATH
this.getClass().getClassLoader().getResourceAsStream("C://EJ_Service//config.properties")
When it is not, config.properties won't be accessible.
You can try some other alternative and use the configFile.load() function to read from.
One example would be:
InputStream inputStream = new FileInputStream(new File("C:/EJ_Service/config.properties"));
configFile.load(inputStream);

Java: opening a resource (txt file) which is in a jar with OS standard application

i get the error "AWT-EventQueue-0 java.lang.IllegalArgumentException: URI is not hierarchical".
-I'm trying to use the java.awt.Desktop api to open a text file with the OS's default application.
-The application i'm running is launched from the autorunning jar.
I understand that getting a "file from a file" is not the correct way and that it's called resource. I still can't open it and can't figure out how to do this.
open(new File((this.getClass().getResource("prova.txt")).toURI()));
Is there a way to open the resource with the standard os application from my application?
Thx :)

You'd have to extract the file from the Jar to the temp folder and open that temporary file, much like you would do with files in a Zip-file (which a Jar basically is).

You do not have to extract file to /tmp folder. You can read it directly using `getClass().getResourceAsStream()'. But note that path depend on where your txt file is and what's your class' package. If your txt file is packaged in root of jar use '"/prova.txt"'. (pay attention on leading slash).

I don't think you can open it with external applications. As far as i know, all installers extract their compressed content to a temp location and delete them afterwards.
But you can do it inside your Java code with Class.getResource(String name)
http://download.oracle.com/javase/6/docs/api/java/lang/Class.html#getResource(java.lang.String)

Wrong
open(new File((this.getClass().getResource("prova.txt")).toURI()));
Right
/**
Do you accept the License Agreement of XYZ app.?
*/
import java.awt.Dimension;
import javax.swing.*;
import java.net.URL;
import java.io.File;
import java.io.IOException;
class ShowThyself {
public static void main(String[] args) throws Exception {
// get an URL to a document..
File file = new File("ShowThyself.java");
final URL url = file.toURI().toURL();
// ..then do this
SwingUtilities.invokeLater( new Runnable() {
public void run() {
JEditorPane license = new JEditorPane();
try {
license.setPage(url);
JScrollPane licenseScroll = new JScrollPane(license);
licenseScroll.setPreferredSize(new Dimension(305,90));
int result = JOptionPane.showConfirmDialog(
null,
licenseScroll,
"EULA",
JOptionPane.OK_CANCEL_OPTION);
if (result==JOptionPane.OK_OPTION) {
System.out.println("Install!");
} else {
System.out.println("Maybe later..");
}
} catch(IOException ioe) {
JOptionPane.showMessageDialog(
null,
"Could not read license!");
}
}
});
}
}

There is JarFile and JarEntry classes from JDK. This allows to load a file from JarFile.
JarFile jarFile = new JarFile("jar_file_Name");
JarEntry entry = jarFile.getJarEntry("resource_file_Name_inside_jar");
InputStream stream = jarFile.getInputStream(entry); // this input stream can be used for specific need

If what you're passing to can accept a java.net.URLthis will work:
this.getClass().getResource("prova.txt")).toURI().toURL()