android - draw image on canvas and save into sd card -

i tried use following codes to

1. draw on canvas
2. save canvas on image

problem - when try save image, shows error permission denied.my error log below.

code draw on canvas:

public mydrawview(context c, attributeset attrs) {         super(c, attrs);         mpath = new path();         mbitmappaint = new paint(paint.dither_flag);         mpaint = new paint();         mpaint.setantialias(true);         mpaint.setdither(true);         mpaint.setcolor(0xff000000);         mpaint.setstyle(paint.style.stroke);         mpaint.setstrokejoin(paint.join.round);         mpaint.setstrokecap(paint.cap.round);         mpaint.setstrokewidth(9);     }      @override     protected void onsizechanged(int w, int h, int oldw, int oldh) {         super.onsizechanged(w, h, oldw, oldh);         mbitmap = bitmap.createbitmap(w, h, bitmap.config.argb_8888);         mcanvas = new canvas(mbitmap);     }      @override     protected void ondraw(canvas canvas) {         canvas.drawbitmap(mbitmap, 0, 0, mbitmappaint);         canvas.drawpath(mpath, mpaint);         }      private float mx, my;     private static final float touch_tolerance = 4;      private void touch_start(float x, float y) {         mpath.reset();         mpath.moveto(x, y);         mx = x;         = y;     }     private void touch_move(float x, float y) {         float dx = math.abs(x - mx);         float dy = math.abs(y - my);         if (dx >= touch_tolerance || dy >= touch_tolerance) {             mpath.quadto(mx, my, (x + mx)/2, (y + my)/2);             mx = x;             = y;         }     }     private void touch_up() {         mpath.lineto(mx, my);         // commit path our offscreen         mcanvas.drawpath(mpath, mpaint);         // kill don't double draw         mpath.reset();     }      @override     public boolean ontouchevent(motionevent event) {         float x = event.getx();         float y = event.gety();          switch (event.getaction()) {             case motionevent.action_down:                 touch_start(x, y);                 invalidate();                 break;             case motionevent.action_move:                 touch_move(x, y);                 invalidate();                 break;             case motionevent.action_up:                 touch_up();                 invalidate();                 break;         }         return true;     }      public bitmap getbitmap() {         this.setdrawingcacheenabled(true);           this.builddrawingcache();         bitmap bmp = bitmap.createbitmap(this.getdrawingcache());            this.setdrawingcacheenabled(false);     return bmp;    }      public void clear(){         mbitmap.erasecolor(color.green);         invalidate();         system.gc();         }  } 

second code save canvas image in main activity. since beginner, appreciate advice.

second code mainactivity:

public class mainactivity extends activity { mydrawview mydrawview;  @override protected void oncreate(bundle savedinstancestate) {      super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     mydrawview = (mydrawview) findviewbyid(r.id.draw);     button button1 = (button) findviewbyid(r.id.button1);     button1.setonclicklistener(new view.onclicklistener() {         public void onclick(view v) {              file folder = new file(environment                     .getexternalstoragedirectory().getabsolutepath()+"/folder image");             if (!folder.exists()) {                 folder.mkdirs();             }              file file = new file(folder,"sample.png");              if (!file.exists()) {                 try {                     file.createnewfile();                 } catch (ioexception e) {                     e.printstacktrace();                 }             }               fileoutputstream ostream = null;             try {                 ostream = new fileoutputstream(file);                  system.out.println(ostream);                 view targetview = mydrawview;                  bitmap = mydrawview.getbitmap();                 bitmap save = bitmap.createbitmap(320, 480, config.argb_8888);                 paint paint = new paint();                 paint.setcolor(color.white);                 canvas = new canvas(save);                 now.drawrect(new rect(0, 0, 320, 480), paint);                 now.drawbitmap(well, new rect(0, 0, well.getwidth(), well.getheight()), new rect(0, 0, 320, 480), null);                  if (save == null) {                     system.out.println("null bitmap save\n");                 }                 save.compress(bitmap.compressformat.png, 100, ostream);             } catch (nullpointerexception e) {                 e.printstacktrace();                 toast.maketext(getapplicationcontext(), "null error", toast.length_short).show();             } catch (filenotfoundexception e) {                 e.printstacktrace();                 toast.maketext(getapplicationcontext(), "file error", toast.length_short).show();             } catch (ioexception e) {                 e.printstacktrace();                 toast.maketext(getapplicationcontext(), "io error", toast.length_short).show();             }          }     });  }  @override public boolean oncreateoptionsmenu(menu menu) {     getmenuinflater().inflate(r.menu.main, menu);     return true; } } 

my error log is:

12-16 13:12:13.848: w/system.err(2010): java.io.ioexception: open failed: eacces (permission denied) 12-16 13:12:13.848: w/system.err(2010):     @ java.io.file.createnewfile(file.java:940) 12-16 13:12:13.848: w/system.err(2010):     @ com.example.drawimage.mainactivity$1.onclick(mainactivity.java:48) 12-16 13:12:13.848: w/system.err(2010):     @ android.view.view.performclick(view.java:4084) 12-16 13:12:13.848: w/system.err(2010):     @ android.view.view$performclick.run(view.java:16966) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.handler.handlecallback(handler.java:615) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.handler.dispatchmessage(handler.java:92) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.looper.loop(looper.java:137) 12-16 13:12:13.848: w/system.err(2010):     @ android.app.activitythread.main(activitythread.java:4745) 12-16 13:12:13.848: w/system.err(2010):     @ java.lang.reflect.method.invokenative(native method) 12-16 13:12:13.848: w/system.err(2010):     @ java.lang.reflect.method.invoke(method.java:511) 12-16 13:12:13.848: w/system.err(2010):     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:786) 12-16 13:12:13.848: w/system.err(2010):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 12-16 13:12:13.848: w/system.err(2010):     @ dalvik.system.nativestart.main(native method) 12-16 13:12:13.848: w/system.err(2010): caused by: libcore.io.errnoexception: open failed: eacces (permission denied) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.posix.open(native method) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.blockguardos.open(blockguardos.java:110) 12-16 13:12:13.848: w/system.err(2010):     @ java.io.file.createnewfile(file.java:933) 12-16 13:12:13.848: w/system.err(2010):     ... 12 more 12-16 13:12:13.848: w/system.err(2010): java.io.filenotfoundexception: /mnt/sdcard/folder image/sample.png: open failed: eacces (permission denied) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.iobridge.open(iobridge.java:416) 12-16 13:12:13.848: w/system.err(2010):     @ java.io.fileoutputstream.<init>(fileoutputstream.java:88) 12-16 13:12:13.848: w/system.err(2010):     @ java.io.fileoutputstream.<init>(fileoutputstream.java:73) 12-16 13:12:13.848: w/system.err(2010):     @ com.example.drawimage.mainactivity$1.onclick(mainactivity.java:58) 12-16 13:12:13.848: w/system.err(2010):     @ android.view.view.performclick(view.java:4084) 12-16 13:12:13.848: w/system.err(2010):     @ android.view.view$performclick.run(view.java:16966) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.handler.handlecallback(handler.java:615) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.handler.dispatchmessage(handler.java:92) 12-16 13:12:13.848: w/system.err(2010):     @ android.os.looper.loop(looper.java:137) 12-16 13:12:13.848: w/system.err(2010):     @ android.app.activitythread.main(activitythread.java:4745) 12-16 13:12:13.848: w/system.err(2010):     @ java.lang.reflect.method.invokenative(native method) 12-16 13:12:13.848: w/system.err(2010):     @ java.lang.reflect.method.invoke(method.java:511) 12-16 13:12:13.848: w/system.err(2010):     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:786) 12-16 13:12:13.848: w/system.err(2010):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 12-16 13:12:13.848: w/system.err(2010):     @ dalvik.system.nativestart.main(native method) 12-16 13:12:13.848: w/system.err(2010): caused by: libcore.io.errnoexception: open failed: eacces (permission denied) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.posix.open(native method) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.blockguardos.open(blockguardos.java:110) 12-16 13:12:13.848: w/system.err(2010):     @ libcore.io.iobridge.open(iobridge.java:400) 12-16 13:12:13.848: w/system.err(2010):     ... 14 more 

androidmanifest.xml:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.example.drawimage"     android:versioncode="1"     android:versionname="1.0" >      <uses-sdk         android:minsdkversion="8"         android:targetsdkversion="21" />     <uses-permission android:name="android.permission.read_external_storage"/>     <uses-permission android:name="android.permission.write_external_storage"/>      <application         android:allowbackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/apptheme" >         <activity             android:name=".mainactivity"             android:label="@string/app_name" >             <intent-filter>                 <action android:name="android.intent.action.main" />                  <category android:name="android.intent.category.launcher" />             </intent-filter>         </activity>     </application>  </manifest> 

you should not call folder "/folder image", remove space should fine.