java - Writing multiple images to ServletOuputStream? -

-

i've requirement multiple images web service(ex:list) , have write images servletoutputstream.

when click on 'view' link invokes servlet , servlet invokes webservice , receives multiple images list.

now i'm trying write images servletoutputstream not working..

trying send images zip

response.setcontenttype("application/zip");   outputstream os = null; bufferedoutputstream bos = null; zipoutputstream zos = null;      try{     os = resp.getoutputstream();     bos = new bufferedoutputstream(os);      zos = new zipoutputstream(bos);     zos.setlevel(zipoutputstream.stored);      sendmultiplefiles(zos, annotcontent,"display"); }catch (ioexception e) {     resp.setstatus(httpservletresponse.sc_internal_server_error); } {     if (zos != null) {         zos.finish();         zos.flush();     }     bos.close();     os.close(); }  private void sendmultiplefiles(zipoutputstream zos, collection<byte[]> filestosend, string name) throws ioexception {     mylogger.info("sendmultiplefiles invoked..");     for(byte[] f: filestosend) {          inputstream instream = null;         zipentry ze = null;          try {             instream = new bytearrayinputstream(f);              ze = new zipentry(name + "-archived");             ze.setcomment("dummy file");              zos.putnextentry(ze);             int readbyte = 0;             while((readbyte = instream.read()) != -1)             {                 zos.write(readbyte);             }         } catch (ioexception e) {             system.out.println("cannot find " );         } {             if (ze != null) {                 zos.closeentry();             }             instream.close();          }     }

above code not working..any suggestions appreciated..

your solution depend on content-type serving - if serving html response issue can resolved either storing images on disk (outside context root , writing image display endpoint) or if images small - sending bytes out base64 encoding in image tag directly.

if response type not html - here options - return zip file.

less standard way of using servlet multipart mime extension.

edit: per comment mime type jpeg - 1 option combine jpeg 1 larger 1 (cannot send multiple out). combining bytes of binary file - jpeg has it's own format compression along header, footer , exif info - may need specialized apis combine them one. here 1 came across. if combining jpg not option - trying achieve cannot done in 1 write.


Comments

Post a Comment

Popular posts from this blog

java - Custom OutputStreamAppender not run: LOGBACK: No context given for <MYAPPENDER> -

-
i wish write custom appender on basis of outputstreamappender . wrote following class package tests; import java.io.ioexception; import java.io.outputstream; import ch.qos.logback.core.outputstreamappender; public class myappender<e> extends outputstreamappender<e> { public myappender() { system.out.println("myappender created"); setoutputstream(new outputstream() { @override public void write(int b) throws ioexception { throw new unsupportedoperationexception(); } }); } } then wrote following runner: package tests; import org.slf4j.loggerfactory; import ch.qos.logback.classic.logger; public class runner { private static final logger log = (logger) loggerfactory.getlogger(runner.class); public static void main(string[] args) { //log.addappender(new myappender<iloggingevent>()); log.info("hello world"); } } finall...
Read more

java - UML - How would you draw a try catch in a sequence diagram? -

-
Image
is there standard way of drawing try catch sequence diagrams? i've made attempt based on this feel end result doesn't feel right. code diagram based around: public static void save () { try { filehandle filehandle = gdx.files.external(file); filehandle.writestring(boolean.tostring(constantshandler.soundenabled)+"\n", false); (int = 0; < 5; i++) { filehandle.writestring(integer.tostring(constantshandler.highscores[i])+"\n", true); } } catch (throwable e) { } } my attempt note: know still need add loop. that's ok. fragments meant show conditional control flow in sequence diagram. superstructures puts limitations on use of fragments (see pp. 467 of ss2.1.1). should use critical region try part above. , option catch . however, keep telling can take quite freedom in using uml. it's language , such changes in life time. long reader ge...
Read more

c++ - No viable overloaded operator for references a map -

-
i trying use map can make tag names reference number. when try , use it, in code error (6 in total every time reference map): src/main.cpp:25:45: error: no viable overloaded operator[] type 'std::map<std::string, std::string>' const char* idcs = node.child_value(tagmap[3]); this code: #include "pugi/pugixml.hpp" #include <iostream> #include <string> #include <map> int main() { pugi::xml_document doca, docb; std::map<std::string, pugi::xml_node> mapa, mapb; std::map<std::string, std::string> tagmap {{"1", "data"}, {"2", "entry"}, {"3", "id"}, {"4", "content"}}; if (!doca.load_file("a.xml") || !docb.load_file("b.xml")) { std::cout << "can't find input files"; return 1; } (auto& node: doca.child(tagmap[1]).children(tagmap[2])) { co...
Read more