java - jna Pointer in 32 bit JRE -

i using jna call magnification api functions in java.

magimagescalingcallback.java

package jna.extra;  import com.sun.jna.callback; import com.sun.jna.pointer; import com.sun.jna.platform.win32.windef.hrgn; import com.sun.jna.platform.win32.windef.hwnd; import com.sun.jna.platform.win32.windef.rect;  public interface magimagescalingcallback extends callback{     public boolean magimagescalingcallback(hwnd hwnd, pointer srcdata,magimageheader srcheader, pointer destdata,magimageheader destheader,rect source,rect clipped,hrgn dirty); } 

magimageheader.java

package jna.extra;  import java.util.arrays; import java.util.list;  import com.sun.jna.platform.win32.guid.guid;   public class magimageheader extends com.sun.jna.structure {     public int width;     public int height;     public guid format;     public int stride;     public int offset;     public int cbsize;      public list getfieldorder() {         return arrays.aslist("width","height","format","stride","offset","cbsize");     } } 

magnification.java

package jna.extra;  import com.sun.jna.native; import com.sun.jna.platform.win32.windef.dword; import com.sun.jna.platform.win32.windef.hwnd; import com.sun.jna.platform.win32.windef.rect; import com.sun.jna.win32.stdcalllibrary; import com.sun.jna.win32.w32apioptions;   public interface magnification extends stdcalllibrary {      magnification instance = (magnification) native.loadlibrary("magnification", magnification.class,                                                 w32apioptions.default_options);      public boolean maginitialize();      public boolean magsetwindowfilterlist(hwnd hwndmag, dword dword, int i,             hwnd[] excludehwnds);      public boolean magsetwindowsource(hwnd hwndmag, rect sourcerect);      public void maggetwindowfilterlist(hwnd hwndmag, dword dword, int i, hwnd[] test);      public boolean magsetimagescalingcallback(hwnd hwndmag,magimagescalingcallback magimagescalingcallback);      public magimagescalingcallback maggetimagescalingcallback(hwnd hwndmag);  } 

wingdiextra.java

package jna.extra;  import com.sun.jna.platform.win32.windef.dword; import com.sun.jna.platform.win32.wingdi;  public interface wingdiextra extends wingdi {      public dword srccopy = new dword(0x00cc0020);     public dword srcpaint = new dword(0x00ee0086);     public dword srcand = new dword(0x008800c6);     public dword srcinvert = new dword(0x00660046);     public dword srcerase = new dword(0x00440328);      public dword notsrccopy = new dword(0x00330008);     public dword notsrcerase = new dword(0x001100a6);     public dword mergecopy = new dword(0x00c000ca);     public dword mergepaint = new dword(0x00bb0226);      public dword patcopy = new dword(0x00f00021);     public dword patpaint = new dword(0x00fb0a09);     public dword patinvert = new dword(0x005a0049);     public dword dstinvert = new dword(0x00550009);     public dword whiteness = new dword(0x00ff0062);     public dword blackness = new dword(0x00000042);     public dword captureblt = new dword(0x00cc0020 | 0x40000000);     public dword black = new dword(0x00000000);      public long ws_child = 0x40000000l;     public long ws_visible = 0x10000000l;     public long ms_showmagnifiedcursor = 0x0001l;        public long ws_ex_topmost = 0x00000008l;     public long ws_ex_layered = 0x00080000;     public long ws_ex_transparent = 0x00000020l;      public long ws_clipchildren = 0x02000000l;      public long mw_filtermode_exclude = 0;  } 

my code

package jna.extra;  import java.awt.image.bufferedimage; import java.io.file; import java.io.ioexception;  import javax.imageio.imageio;  import com.sun.jna.platform.win32.kernel32; import com.sun.jna.platform.win32.windef.dword; import com.sun.jna.platform.win32.windef.hrgn; import com.sun.jna.platform.win32.windef.rect; import com.sun.jna.platform.win32.windef.hwnd; import com.sun.jna.native; import com.sun.jna.pointer;  import luz.winapi.jna.user32;  public class screenskip {      public static void main(string[] args){         if(!magnification.instance.maginitialize()){             system.out.println("cannot intialize magnification api");             system.exit(0);         }          rect desktoprect= new rect();         hwnd desktop = user32.instance.getdesktopwindow();         if(desktop==null){             system.out.println("problem desktop");             system.exit(0);         }         if(!user32extra.instance.getwindowrect(desktop, desktoprect)){             system.err.println("cannot window rect");             system.exit(0);         }         hwnd top = user32extra.instance.createwindowex(new dword(wingdiextra.ws_ex_topmost | wingdiextra.ws_ex_layered | wingdiextra.ws_ex_transparent), "#32770", "parent window", new dword(wingdiextra.ws_clipchildren), desktoprect.left, desktoprect.top, desktoprect.right-desktoprect.left, desktoprect.bottom-desktoprect.top, desktop, null, null, null);          if(top==null){             system.out.println("problem while creating parent window , error "+native.getlasterror());             system.exit(0);         }          hwnd hwndmag=null;         system.out.println(native.getlasterror());         hwndmag = user32extra.instance.createwindowex(null, "magnifier", "magwindow", new dword(wingdiextra.ws_child | wingdiextra.ms_showmagnifiedcursor | wingdiextra.ws_visible), desktoprect.left, desktoprect.top, desktoprect.right-desktoprect.left, desktoprect.bottom-desktoprect.top, top, null, kernel32.instance.getmodulehandle(null), null);         if(hwndmag==null){             system.err.println("problem while creating magnifier window , error "+native.getlasterror());             system.exit(0);         }          rect sourcerect= new rect();          if(!user32extra.instance.getwindowrect(desktop, sourcerect)){             system.err.println("cannot window rect");             system.exit(0);         }          final bufferedimage image = new bufferedimage(1366, 768, bufferedimage.type_int_rgb);         if(!magnification.instance.magsetimagescalingcallback(hwndmag,new magimagescalingcallback() {              public boolean magimagescalingcallback(hwnd hwnd, pointer srcdata,                     magimageheader srcheader, pointer destdata,                     magimageheader destheader, rect source, rect clipped, hrgn dirty) {                 image.setrgb(0, 0, srcheader.width, srcheader.height, srcdata.getintarray(0, srcheader.width * srcheader.height ), 0, srcheader.width);                 return true;             }         })){             system.err.println("error occured while setting callback");             system.exit(0);         }         if (!magnification.instance.magsetwindowsource(hwndmag, sourcerect))         {             system.err.println("cannot copy");             system.exit(0);         }         try {             imageio.write(image, "jpeg", new file("printed1.jpg"));         } catch (ioexception e) {             e.printstacktrace();         }         if (!magnification.instance.magsetwindowsource(hwndmag, sourcerect))         {             system.err.println("cannot copy");             system.exit(0);         }     } } 

if magsetwindowsource function called magimagescalingcallback function called.

the problem if run code jre7(64 bit) works fine. if run same code in jre7(32 bit), getting following error.

 # # fatal error has been detected java runtime environment: # #  exception_access_violation (0xc0000005) @ pc=0x10002a21, pid=5552, tid=4884 # # jre version: java(tm) se runtime environment (7.0_80-b15) (build 1.7.0_80-b15) # java vm: java hotspot(tm) client vm (24.80-b11 mixed mode, sharing windows-x86 ) # problematic frame: # c  [jna6797525900717560222.dll+0x2a21] # # failed write core dump. minidumps not enabled default on client versions of windows # # if submit bug report, please visit: #   http://bugreport.java.com/bugreport/crash.jsp # crash happened outside java virtual machine in native code. # see problematic frame report bug. #  stack: [0x05c60000,0x05cb0000],  sp=0x05cae4d0,  free space=313k native frames: (j=compiled java code, j=interpreted, vv=vm code, c=native code) c  [jna6797525900717560222.dll+0x2a21] j  com.sun.jna.pointer._getint(j)i+0 j  com.sun.jna.pointer.getint(j)i+6 j  com.sun.jna.pointer.getvalue(jljava/lang/class;ljava/lang/object;)ljava/lang/object;+340 j  com.sun.jna.structure.readfield(lcom/sun/jna/structure$structfield;)ljava/lang/object;+168 j  com.sun.jna.structure.read()v+82 j  com.sun.jna.callbackreference$defaultcallbackproxy.convertargument(ljava/lang/object;ljava/lang/class;)ljava/lang/object;+330 j  com.sun.jna.callbackreference$defaultcallbackproxy.invokecallback([ljava/lang/object;)ljava/lang/object;+95 j  com.sun.jna.callbackreference$defaultcallbackproxy.callback([ljava/lang/object;)ljava/lang/object;+2 v  ~stubroutines::call_stub v  [jvm.dll+0x1429aa] v  [jvm.dll+0x20743e] v  [jvm.dll+0x142a2d] v  [jvm.dll+0xcb7b2] v  [jvm.dll+0xcd5df] c  [jna6797525900717560222.dll+0x9dd2] c  [jna6797525900717560222.dll+0xa47f] c  [jna6797525900717560222.dll+0xc864] c  [jna6797525900717560222.dll+0xcdee] c  0x00b80012 c  [magnification.dll+0x5434] c  [magnification.dll+0x5a2c] c  [magnification.dll+0x5f5d] c  [magnification.dll+0x612a] c  [magnification.dll+0x28ab] c  [user32.dll+0x162fa] c  [user32.dll+0x16d3a] c  [user32.dll+0x1965e] c  [user32.dll+0x196c5] c  [magnification.dll+0x22e2] c  [jna6797525900717560222.dll+0xcc77] c  [jna6797525900717560222.dll+0xc78a] c  [jna6797525900717560222.dll+0x4561] c  [jna6797525900717560222.dll+0x4d2e] j  com.sun.jna.function.invokeint(i[ljava/lang/object;)i+0 j  com.sun.jna.function.invoke([ljava/lang/object;ljava/lang/class;z)ljava/lang/object;+315 j  com.sun.jna.function.invoke(ljava/lang/class;[ljava/lang/object;ljava/util/map;)ljava/lang/object;+214 j  com.sun.jna.library$handler.invoke(ljava/lang/object;ljava/lang/reflect/method;[ljava/lang/object;)ljava/lang/object;+341 j  com.sun.proxy.$proxy5.magsetwindowsource(lcom/sun/jna/platform/win32/windef$hwnd;lcom/sun/jna/platform/win32/windef$rect;)z+20 j  org.redfire.screen.screenshare$capturescreen.run()v+674 j  java.lang.thread.run()v+11 v  ~stubroutines::call_stub v  [jvm.dll+0x1429aa] v  [jvm.dll+0x20743e] v  [jvm.dll+0x142b75] v  [jvm.dll+0x142bd7] v  [jvm.dll+0xed5cf] v  [jvm.dll+0x163c4c] v  [jvm.dll+0x1646a7] v  [jvm.dll+0x1a92f9] c  [msvcr100.dll+0x5c556] c  [msvcr100.dll+0x5c600] c  [kernel32.dll+0x133aa] c  [ntdll.dll+0x39f72] c  [ntdll.dll+0x39f45]  java frames: (j=compiled java code, j=interpreted, vv=vm code) j  com.sun.jna.pointer._getint(j)i+0 j  com.sun.jna.pointer.getint(j)i+6 j  com.sun.jna.pointer.getvalue(jljava/lang/class;ljava/lang/object;)ljava/lang/object;+340 j  com.sun.jna.structure.readfield(lcom/sun/jna/structure$structfield;)ljava/lang/object;+168 j  com.sun.jna.structure.read()v+82 j  com.sun.jna.callbackreference$defaultcallbackproxy.convertargument(ljava/lang/object;ljava/lang/class;)ljava/lang/object;+330 j  com.sun.jna.callbackreference$defaultcallbackproxy.invokecallback([ljava/lang/object;)ljava/lang/object;+95 j  com.sun.jna.callbackreference$defaultcallbackproxy.callback([ljava/lang/object;)ljava/lang/object;+2 v  ~stubroutines::call_stub j  com.sun.jna.function.invokeint(i[ljava/lang/object;)i+0 j  com.sun.jna.function.invoke([ljava/lang/object;ljava/lang/class;z)ljava/lang/object;+315 j  com.sun.jna.function.invoke(ljava/lang/class;[ljava/lang/object;ljava/util/map;)ljava/lang/object;+214 j  com.sun.jna.library$handler.invoke(ljava/lang/object;ljava/lang/reflect/method;[ljava/lang/object;)ljava/lang/object;+341 j  com.sun.proxy.$proxy5.magsetwindowsource(lcom/sun/jna/platform/win32/windef$hwnd;lcom/sun/jna/platform/win32/windef$rect;)z+20 j  org.redfire.screen.screenshare$capturescreen.run()v+674 j  java.lang.thread.run()v+11 v  ~stubroutines::call_stub   

how solve issue? how can make work on 32-bit jre? thanks!

firstly, magimagescalingcallback defined winapi function, means have define callback being child of stdcallcallback.

secondly, return type simple boolean (you should not use boolean this).

thirdly, parameters of callback magimageheader, , not magimageheader *, , rect not rect *, means needs passed value; callback declaration needs changed so:

i added rectbyvalue class, containing following:

import com.sun.jna.platform.win32.windef; import com.sun.jna.structure;  public class rectbyvalue extends windef.rect implements structure.byvalue {} 

i changed magimagescalingcallback class following:

import com.sun.jna.win32.stdcalllibrary;  public interface magimagescalingcallback extends stdcalllibrary.stdcallcallback {    public boolean magimagescalingcallback(hwnd hwnd, pointer srcdata,magimageheader.byvalue srcheader, pointer destdata,magimageheader.byvalue destheader,rectbyvalue source,rectbyvalue clipped,hrgn dirty); } 

you need add byvalue support magimageheader; , use size_t last element of structure:

import java.util.arrays; import java.util.list;  import com.sun.jna.platform.win32.guid.guid; import com.sun.jna.platform.win32.basetsd; import com.sun.jna.pointer; import com.sun.jna.structure;  public class magimageheader extends structure {     public int width;     public int height;     public guid format;     public int stride;     public int offset;     public basetsd.size_t cbsize;      public list getfieldorder() {         return arrays.aslist("width","height","format", "stride","offset","cbsize");     }      public static class byvalue extends magimageheader implements structure.byvalue {         public byvalue() {}          public byvalue(magimageheader magimageheader) {             super (magimageheader.getpointer());              width = magimageheader.width;             height = magimageheader.height;             format = magimageheader.format;             stride = magimageheader.stride;             offset = magimageheader.offset;             cbsize = magimageheader.cbsize;         }          public byvalue(pointer memory) {             super(memory);         }     }      public magimageheader(pointer memory) {         super(memory);         read();     }      public magimageheader() {     } } 

i changed screen size match display on screenskip it's new bufferedimage(2160, 1440... instead of 1366, 786, , changed callback code creator to:

if(!magnification.instance.magsetimagescalingcallback(hwndmag, new magimagescalingcallback() {      public boolean magimagescalingcallback(hwnd hwnd, pointer srcdata,             magimageheader.byvalue srcheader, pointer destdata,             magimageheader.byvalue destheader, rectbyvalue source, rectbyvalue clipped, hrgn dirty) {         image.setrgb(0, 0, srcheader.width, srcheader.height, srcdata.getintarray(0, srcheader.width * srcheader.height ), 0, srcheader.width);         return true;     } })){     system.err.println("error occured while setting callback");     system.exit(0); } 

the end product of running in 32bit or 64bit mode file called minimal can think achieve want.

.... huh ... gives me blank image on 32bit. seems incorrect.