android - java.io.StreamCorruptedException:Wrong format:56 -

during time, develop android application, use object[input/output]stream send/receive message.the following code send method:

public void sendmsg(message msg) {     try {         if(connectedfalg) {             outputstream.reset();             outputstream.writeobject(msg);             outputstream.flush();         }     } catch (ioexception e) {         // todo auto-generated catch block         e.printstacktrace();     } } 

at same time, there thread receive message time, code following:

while(true) {     try {         message msg = (message) inputstream.readobject();         buffermanager.instance.addreceivequeue(msg);     } catch (optionaldataexception e) {         // todo auto-generated catch block         e.printstacktrace();     } catch (ioexception e) {         // todo auto-generated catch block         e.printstacktrace();     } catch (classnotfoundexception e) {         // todo auto-generated catch block         e.printstacktrace();     } } 

in project, have 3 ball, 1 ball target ball, others controlled mobile phone accelerate sensor.at first send state of no.1 ball, , send no.2 ball or target ball, have exception.like:

java.io.streamcorruptedexception:wrong format:56 05-15 21:53:02.220: w/system.err(5923):     @ java.io.objectinputstream.corruptstream(objectinputstream.java:676) 05-15 21:53:02.230: w/system.err(5923):     @ java.io.objectinputstream.readnonprimitivecontent(objectinputstream.java:789) 

and times have problem:

05-16 15:42:28.380: w/system.err(14690): java.io.utfdataformatexception: bad byte @ 122 

05-16 15:42:28.380: w/system.err(14690): @ java.nio.charset.modifiedutf8.decode(modifiedutf8.java:60) 05-16 15:42:28.380: w/system.err(14690): @ java.io.datainputstream.decodeutf(datainputstream.java:179) 05-16 15:42:28.380: w/system.err(14690): @ java.io.datainputstream.decodeutf(datainputstream.java:173) 05-16 15:42:28.380: w/system.err(14690): @ java.io.datainputstream.readutf(datainputstream.java:169) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readfielddescriptors(objectinputstream.java:895) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readclassdescriptor(objectinputstream.java:1719) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readnewclassdesc(objectinputstream.java:1631) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readclassdesc(objectinputstream.java:658) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readnewobject(objectinputstream.java:1781) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readnonprimitivecontent(objectinputstream.java:762) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readobject(objectinputstream.java:1981) 05-16 15:42:28.380: w/system.err(14690): @ java.io.objectinputstream.readobject(objectinputstream.java:1938)

this project https://github.com/aresxiao/datastreamengine/tree/dev

if 2 ball collide, call collisioncalculate() method,the method following:

public boolean collisioncalculate(float ballatempxy[],abstractball balla,abstractball ballb) {             value bvalue = kvstoreinmemory.instance.getversionvalue(new key(ballb.getballid())).getvalue();     float[] bloc = bvalue.getloc();      float bax = ballatempxy[0] - bloc[0];     float bay = ballatempxy[1] - bloc[1];      float mvba = mould(new float[]{bax, bay});        if(mvba > (balla.getradius() + ballb.getradius())){          return false;     }      float[] bv = bvalue.getv();      float vb = (float)math.sqrt(bv[0] * bv[0] + bv[1] * bv[1]);      float vbcollx = 0;     float vbcolly = 0;     //垂直方向的xy分速度     float vbverticalx=0;     float vbverticaly=0;      if(balla.getvmin() < vb)     {         float bangle=angle         (             new float[]{bv[0],bv[1]},             new float[]{bax,bay}         );          float vbcoll=vb * (float)math.cos(bangle);          vbcollx = (vbcoll/mvba) * bax;         vbcolly = (vbcoll/mvba) * bay;          vbverticalx = bv[0] - vbcollx;         vbverticaly = bv[1] - vbcolly;     }      value avalue = kvstoreinmemory.instance.getversionvalue(new key(balla.getballid())).getvalue();      float[] av = avalue.getv();      float va = (float)math.sqrt(av[0] * av[0] + av[1] * av[1]);     //平行方向的xy分速度     float vacollx = 0;     float vacolly = 0;     //垂直方向的xy分速度     float vaverticalx = 0;     float vaverticaly = 0;      if(balla.getvmin() < va)     {         float aangle=angle         (             new float[]{av[0],av[1]},             new float[]{bax,bay}         );                    float vacoll=va*(float)math.cos(aangle);          vacollx=(vacoll/mvba)*bax;         vacolly=(vacoll/mvba)*bay;          vaverticalx = av[0]-vacollx;         vaverticaly = av[1]-vacolly;     }      av[0] = vaverticalx + vbcollx;     av[1] = vaverticaly + vbcolly;     avalue.setv(av[0], av[1]);      registercontrollerfactory.instance.getregistercontroller().write(new key(balla.getballid()), avalue);     system.out.println("write balla "+balla.getballid());     bv[0] = vbverticalx + vacollx;     bv[1] = vbverticaly + vacolly;      bvalue.setv(bv[0], bv[1]);     registercontrollerfactory.instance.getregistercontroller().write(new key(ballb.getballid()), bvalue);     system.out.println("write ballb "+ballb.getballid());      return true; }