来个高手指导下

枯萎的花

sget-object v2 Lcom/sdk/code/SV;->HEX_DIGITS:[C
aget-byte v3 v4 v0
and-int/lit16 v3 v3 240
ushr-int/lit8 v3 v3 4
aget-char v2 v2 v3
invoke-virtual {v1,v2} Ljava/lang/StringBuilder;->append(C)Ljava/lang/StringBuilder;
sget-object v2 Lcom/sdk/code/SV;->HEX_DIGITS:[C
aget-byte v3 v4 v0
and-int/lit8 v3 v3 15
aget-char v2 v2 v3
invoke-virtual {v1,v2} Ljava/lang/StringBuilder;->append(C)Ljava/lang/StringBuilder;
add-int/lit8 v0 v0 1
goto :label_9

请告诉下是什么意思