[Android / PHP / MySQL] Sauvegarder une image

salut tout le monde.je développe une application android mais je rencontre un grand problème sur l'envoi des images vers le serveur mysql via php
voici mes erreurs



03-18 22:59:44.777: W/dalvikvm(8781): Unable to resolve superclass of Lcom/example/app/AndroidMultiPartEntity; (132)
03-18 22:59:44.777: W/dalvikvm(8781): Link of class 'Lcom/example/app/AndroidMultiPartEntity;' failed
03-18 22:59:44.777: E/dalvikvm(8781): Could not find class 'com.example.app.AndroidMultiPartEntity', referenced from method com.example.app.UploadActivity$UploadFileToServer.uploadFile
03-18 22:59:44.777: W/dalvikvm(8781): VFY: unable to resolve new-instance 45 (Lcom/example/app/AndroidMultiPartEntity;) in Lcom/example/app/UploadActivity$UploadFileToServer;
03-18 22:59:44.777: D/dalvikvm(8781): VFY: replacing opcode 0x22 at 0x000d
03-18 22:59:44.777: W/dalvikvm(8781): Unable to resolve superclass of Lcom/example/app/AndroidMultiPartEntity; (132)
03-18 22:59:44.777: W/dalvikvm(8781): Link of class 'Lcom/example/app/AndroidMultiPartEntity;' failed