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http断点续传简单实现(java)

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/* ^@n?&  
**SiteFileFetch.java . KzU7  
*/ |$.`4h?  
package NetFox; tFYo d#  
import java.io.*; Kv>P+I'|r  
import java.net.*; v?qU/  
=S}SZYw l  
`l`)Cs;a  
public class SiteFileFetch extends Thread {  `\#J&N  
! 6: X]  
yM*f}S/ (  
SiteInfoBean siteInfoBean = null; //文件信息Bean rIZ^ix-N  
long[] nStartPos; //开始位置 ).9m6.%Uk  
long[] nEndPos; //结束位置 ^|ln q.j  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4 .d~u@=  
long nFileLength; //文件长度 EnnE@BJ"  
boolean bFirst = true; //是否第一次取文件 u40<>A  
boolean bStop = false; //停止标志 f" g-Hbl5  
File tmpFile; //文件下载的临时信息 ?'r=>'6D  
DataOutputStream output; //输出到文件的输出流 |$a!Zx94^  
UU" '  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) d{G*1l(X  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1;N5@0%p  
{ E [b6k&A  
siteInfoBean = bean; 1|/]bffg!c  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); iF'qaqHWY4  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !1cVg ls|  
if(tmpFile.exists ()) tg' 2 v/  
{ `78)|a*R.  
bFirst = false; U%E364;F  
read_nPos(); SK G!DKQ  
}  ]pP:  
else UKBaGX:v  
{ QO(P_az3mg  
nStartPos = new long[bean.getNSplitter()]; !f!HVna  
nEndPos = new long[bean.getNSplitter()]; >7I"_#x1:  
} A/w7 (  
55#s/`gd)^  
B~t[Gy  
?0k4l8R  
} lzup! `g  
TuX9:Q  
Rt2<F-gY  
public void run() af<wUxM0  
{ m6^n8%  
//获得文件长度 <maY S2  
//分割文件 TW5Pt{X= f  
//实例FileSplitterFetch N9=1<{Z  
//启动FileSplitterFetch线程 f?|cQ[#t!\  
//等待子线程返回 z*B-`i.  
try{ F>/"If#  
if(bFirst) b'$fr6"O1  
{ p`2w\P3;)  
nFileLength = getFileSize(); oVYW '~OID  
if(nFileLength == -1) S1D=' k]  
{ WXX)_L$2  
System.err.println("File Length is not known!"); yITL;dBy  
} U9eb&nd  
else if(nFileLength == -2) aokV'6  
{ &yN/ AY`U  
System.err.println("File is not access!"); CFyu9Al  
} akB+4?+s)  
else yTwtGo&  
{ $Y9Wzv3Ra  
for(int i=0;i<nStartPos.length;i++) %RX}sS  
{ ?'I pR  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); mcqLN5  
} r}Ec_0_lt  
for(int i=0;i<nEndPos.length-1;i++) S @[B?sNj  
{ 6 r}R%{  
nEndPos = nStartPos[i+1]; /<-@8CC<  
} @dx$&;w  
nEndPos[nEndPos.length-1] = nFileLength; C])b 3tM,7  
} m6 @,J?X  
} z6>Rv9f  
J.^%VnrFO9  
VYC$Q;Z  
//启动子线程 @^UnrKSd  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ipdGAG  
for(int i=0;i<nStartPos.length;i++) C|hD^m  
{ L92vb zP  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k1HVvMD<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dD.;P=AP  
nStartPos,nEndPos,i); "Q <  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FhVoN}  
fileSplitterFetch.start(); lbUUf}   
} nOj0"c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (&^k''f  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;N;['xcx;  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ('Doy1L  
nEndPos = " + nFileLength); nkii0YB!  
// fileSplitterFetch[nPos.length-1].start(); K! I]0!:  
`D~wY^q{  
9~ JeI/  
//等待子线程结束 7ts`uI<E@7  
//int count = 0; oW\kJ>!  
//是否结束while循环 Kp)H>~cL  
boolean breakWhile = false; R-lpsvDDL2  
uEX+j  
vn Ol-`Z ~  
while(!bStop) WO]9\"|y  
{ .&2Nm&y$ K  
write_nPos(); .5K}R<  
Utility.sleep(500); ;r.0=Uo9]  
breakWhile = true; x}B_;&>&"_  
>3&Oe  
 L$Yg*]\  
for(int i=0;i<nStartPos.length;i++) CS|al(?~  
{ nXFPoR)T  
if(!fileSplitterFetch.bDownOver) (`me}8  
{ "B3&v%b  
breakWhile = false; \~~y1.,U.  
break; i}E&mv'  
} +fRABY5C  
} 3]cW08"c  
if(breakWhile) tTcff9ee  
break; vn5O8sD  
odaCKhdk  
L2<IG)oXU  
//count++; wJ Qm7n-+  
//if(count>4) h5^qo ^;g7  
// siteStop(); FBGe s[,  
} o7=#ye&P  
aTU[H~dTU  
N6UPD11}6  
System.err.println("文件下载结束!"); ` 5lW  
} uZhY)o*]@  
catch(Exception e){e.printStackTrace ();} cf`g.9pjlx  
} _ISaO C{2-  
B57MzIZi]  
#WqpU.  
//获得文件长度 }eq*dr1`  
public long getFileSize() 'Tbdo >y  
{ 3[;fO_R  
int nFileLength = -1; ScCA8JgY  
try{ G%FLt[  
URL url = new URL(siteInfoBean.getSSiteURL()); S\"#E:A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]21`x  
httpConnection.setRequestProperty("User-Agent","NetFox"); DqN<bu2  
" .<>(bE  
s=[T,:Z  
int responseCode=httpConnection.getResponseCode(); $LOwuvu>  
if(responseCode>=400) AJ"a  
{ unD.t  
processErrorCode(responseCode); Ygs:Ox"[-G  
return -2; //-2 represent access is error  up==g  
} d$qi. %<kh  
7,7-E&d  
@t{`KB+ ^  
String sHeader; "OWW -m  
 hSgH;k  
e]DuV)k&  
for(int i=1;;i++) VqL#w<A %  
{ "J"RH:$v  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H9%[! RF  
//Utility.log(in.readLine()); Mfinh@K,  
sHeader=httpConnection.getHeaderFieldKey(i); l?<DY$H 0  
if(sHeader!=null) 'dvi@Jx  
{ _MLbJ  
if(sHeader.equals("Content-Length")) v9 *WM3  
{ ?R":"*eu  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )\RG NJMC  
break; M'|?* aNK  
} )j\9IdkU;y  
} W87kE?,  
else 4H*M^?h\#  
break; h-+vN hH  
} FaQz03N\  
} z0T9tN!(  
catch(IOException e){e.printStackTrace ();} >QSlH]M  
catch(Exception e){e.printStackTrace ();} >1  %|T  
7xh91EU:4  
U%r|hn3  
Utility.log(nFileLength); !%Bhg?  
u2 t=*<X  
RaC8Sq7hW  
return nFileLength; 51gSbkVX  
} 8T5W6Zs1  
76(/(v.x  
DI0Wk^m  
//保存下载信息(文件指针位置) Pe/8=+qO  
private void write_nPos() K,5_{pj  
{ ^I:f4RWo  
try{ Dp-j(F  
output = new DataOutputStream(new FileOutputStream(tmpFile)); q#PMQR"C  
output.writeInt(nStartPos.length); u9u'!hAGH  
for(int i=0;i<nStartPos.length;i++) j.kv!;Rj=  
{ nq qqP  
// output.writeLong(nPos); !S#K6:  
output.writeLong(fileSplitterFetch.nStartPos); L};P*{q2Z  
output.writeLong(fileSplitterFetch.nEndPos); 3g87ir  
} L Z}m;  
output.close(); p\22_m_wd  
} ;pt.)5  
catch(IOException e){e.printStackTrace ();} hV}C.- 6h  
catch(Exception e){e.printStackTrace ();} C 8KV<k  
}  {HbSty  
'37 <+N  
'OI(MuSn  
//读取保存的下载信息(文件指针位置) UK5u"@T  
private void read_nPos() k2/t~|5  
{ h{ T{3  
try{ R5N~%Dg)3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^Eif~v  
int nCount = input.readInt(); dR!x)oO=  
nStartPos = new long[nCount]; SZD7"m4  
nEndPos = new long[nCount]; B|ctauJ  
for(int i=0;i<nStartPos.length;i++) vD76IG jm  
{ 3$4I  
nStartPos = input.readLong(); 3w}ul~>j  
nEndPos = input.readLong(); G * =>  
} w*\JA+  
input.close(); 2sYz$ZGC"#  
} &mkL4 jXG  
catch(IOException e){e.printStackTrace ();} wGgeK,*_  
catch(Exception e){e.printStackTrace ();} a[jNT$8  
} z:oi @q  
n{(,r'  
^G14Z5.  
private void processErrorCode(int nErrorCode) <9]J/w+  
{ [&pMU)   
System.err.println("Error Code : " + nErrorCode); 1EWskmp  
} #xh M&X  
cb }OjM F  
A [_T~+-G  
//停止文件下载 xg;vQKS6  
public void siteStop() ;sAe#b  
{ ?OFfU  4  
bStop = true; Y^b}~t  
for(int i=0;i<nStartPos.length;i++) |]eWO#vs  
fileSplitterFetch.splitterStop(); >{[  
 Y-+JDrK  
l p|`n  
} qNWSDZQ  
} K0|:+s@u  
//负责部分文件的抓取 =klfCFwP  
**FileSplitterFetch.java :A+}fB IN  
*/ 7LsVlT[  
package NetFox; ]F3fO5Z  
VNwOD-b/]  
P6A##z  
import java.io.*; hcoZ5!LvT  
import java.net.*; ?Kg_bvoR  
xAr&sGMA  
)JhB!P(  
public class FileSplitterFetch extends Thread { $!^C|,CS  
+5Ju `Z  
NH4T*R)Vz  
String sURL; //File URL U6#9W}CE  
long nStartPos; //File Snippet Start Position %WPy c%I  
long nEndPos; //File Snippet End Position [Pl''[  
int nThreadID; //Thread's ID B & ]GGy  
boolean bDownOver = false; //Downing is over 5| Oj\L{  
boolean bStop = false; //Stop identical f^lhdZ\  
FileAccessI fileAccessI = null; //File Access interface q+ `QiPj  
N%9?8X[5  
#'y&M t  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {a ]u  
{ EUW>8kw0  
this.sURL = sURL; ~-UO^$M-  
this.nStartPos = nStart; wli H3vA_  
this.nEndPos = nEnd; /4;Sxx-  
nThreadID = id; G +AP."M?  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4m6/ ba  
} 6!H,(Z]j  
UkcH+0o  
\f7R^;`_<R  
public void run() K{:[0oIHc  
{ x,HD,VQR/  
while(nStartPos < nEndPos && !bStop) 55/)2B2J  
{  r}}2 Kl  
!6hV|2aJy  
sl:1P^b  
try{ K^P&3H*(/n  
URL url = new URL(sURL); :i|Bz6Ht4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <fHN^O0TS  
httpConnection.setRequestProperty("User-Agent","NetFox"); Rm`P.;%  
String sProperty = "bytes="+nStartPos+"-"; F`1J&S;C  
httpConnection.setRequestProperty("RANGE",sProperty); 39L_O RMH  
Utility.log(sProperty); o5:md :\  
In8{7&iVO  
9CAu0N5<  
InputStream input = httpConnection.getInputStream(); 7rG+)kHG  
//logResponseHead(httpConnection); iUs_)1  
Y$9x !kV  
,y@WFRsx  
byte[] b = new byte[1024]; R ^ZOcONd-  
int nRead; mY]o_\`  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cPkP/3I]h  
{ S VypR LVB  
nStartPos += fileAccessI.write(b,0,nRead); G8'  
//if(nThreadID == 1) ab`9MJc;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5!aI~(3<  
}  FL b  
g_0| `Sm  
u8gqWsvruM  
Utility.log("Thread " + nThreadID + " is over!"); 0`Uw[Er&  
bDownOver = true; =Y*@8=V  
//nPos = fileAccessI.write (b,0,nRead); "{Hl! Zq/  
} pu_?) U  
catch(Exception e){e.printStackTrace ();} ]x(6^:D5  
} Dl,sl>{  
} NKTy!zWh  
w`v` aw]  
lbPn<  
//打印回应的头信息 V+r&Z<&  
public void logResponseHead(HttpURLConnection con) |T]&8Q)S  
{ y`z4S,  
for(int i=1;;i++) ,L4zhhl!_  
{ Yhjv[9  
String header=con.getHeaderFieldKey(i); wd3OuDrU  
if(header!=null)  FjMKb  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ti7 @{7>  
Utility.log(header+" : "+con.getHeaderField(header)); PPh<9$1\g  
else =RZ PDu  
break; |oSqy  
} gyegdky3  
} ryqu2>(   
qJ2Z5  
X_!km-{  
public void splitterStop() h50]%tp\  
{ x U"g~hT  
bStop = true; Pz\ByD  
} 4iZg2"[D  
u6%\ZK._ \  
)&Z`SaoP|J  
} I8c:U2D  
PHJHW#sv  
C6Cr+TScH  
/* Ikw.L  
**FileAccess.java d[  _@l  
*//文件访问(定位,写) 0g HV(L?  
package NetFox; 'z{|#zd9  
import java.io.*; w#ZzmO  
sLFZ 61rT  
j-VwY/X  
public class FileAccessI implements Serializable{ UZ "!lpg  
sbhzER  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [rW];H8:~  
RandomAccessFile oSavedFile; x-W~&`UU  
long nPos; EhW"s%Q  
Lf%=vd  
dp&G([  
public FileAccessI() throws IOException Zz+v3o0  
{ U| ?68B3  
this("",0); mU"Am0Bdjq  
} <P/odpmc  
W*DK pJy  
_1mpsY<k  
public FileAccessI(String sName,long nPos) throws IOException X|G[Ma?   
{ E " >`  
oSavedFile = new RandomAccessFile(sName,"rw"); oE6`]^^  
this.nPos = nPos; 7WY~v2SDF  
oSavedFile.seek(nPos); 1Kr$JIcd  
} z30 mk  
D u T6Od/f  
sv!v`zh  
public synchronized int write(byte[] b,int nStart,int nLen) ?k($Tc&Q  
{ =F}qT|K  
int n = -1; sI h5cT  
try{ Ul6|LTY  
oSavedFile.write(b,nStart,nLen); [zXC\)&!  
n = nLen; q2'}S A/  
} !^s -~`'\~  
catch(IOException e) cP\z*\dS  
{ !Q5,Zhgr  
e.printStackTrace (); hc3tzB  
} U@CAQ?  
ob'" ^LO\  
#XB3Wden2  
return n; TU58  
} WRwx[[e6z  
Hc[@c)DH  
;yyR_N S  
} +\;Ro18?  
t_*x.{x-  
{QaO\{J=  
/* 4; 0#Z^p  
**SiteInfoBean.java !]E ]Xd<  
*/ $ZZ?*I  
package NetFox; )?7/fF)@|  
gat;Er  
VH<d[Mj  
public class SiteInfoBean { WPAUY<6f  
;\6@s3  
kPiY|EH  
private String sSiteURL; //Site's URL mEu2@3^E }  
private String sFilePath; //Saved File's Path N ~fE&@-  
private String sFileName; //Saved File's Name ULBEe@ s  
private int nSplitter; //Count of Splited Downloading File jT< I`K*  
|=0w_)Fa]  
</@5>hx/  
public SiteInfoBean() x DN u'  
{//nSplitter的缺省值为5 j@^zK!mO  
//default value of nSplitter is 5 c q[nqjC=  
this("","","",5); $Dx*[.M3>  
} zi_$roq=)  
ARt{ 2|  
!8T04988j  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B|yz~wu S  
{ _+nk3-yQw  
sSiteURL= sURL; Tx]p4wY:D  
sFilePath = sPath; w{ |`F>f9  
sFileName = sName; *s-s1v  
this.nSplitter = nSpiltter; UN F\k1[  
^Ifm1$X}  
U<Qi`uoj!  
} +N7<[hE;  
lJ]QAO  
tm1&OY  
public String getSSiteURL() u\= 05N6G  
{ Otx>S' 5  
return sSiteURL; <[-{:dH,5  
} I)vR  
Z 4i5,f  
5Phsh  
public void setSSiteURL(String value) =Ul"{T<  
{  S.B?l_d^  
sSiteURL = value; ::'Y07  
} 7l/lY-zO  
0Z]HH+Z;  
T3<1{"&  
public String getSFilePath() CGlEc  
{  s!  
return sFilePath; &A.0(s  
} wB' !@>db  
wIR"!C>LE  
reArXmU<u  
public void setSFilePath(String value) !iNwJ|0  
{ ]!P8{xmb@  
sFilePath = value; On~KTt3Mp  
} WcS`T?Xa  
)8rF'pxI  
o _l_Yi  
public String getSFileName() 3 yb]d5:U  
{ M% Rr=  
return sFileName; ]+m 2pEO  
} U1Fo #L  
>i  >|]  
8#tuB8>  
public void setSFileName(String value) _yR_u+5  
{ )g^qgxnnV  
sFileName = value; oqysfLJ  
} q+oc^FD?@  
8! !h6dQgI  
)*XWe|H_  
public int getNSplitter() ?PTXgIC  
{ ILl~f\xG)  
return nSplitter; ! l0"nPM=  
} nK+ke)'Zv=  
,ayJgAD  
2gkN\w6zQ  
public void setNSplitter(int nCount) r-!Qw1  
{ \,X)!%6kZ  
nSplitter = nCount; !9YCuHj!p  
} $ (xdF  
} 1n&%L8]  
Sw"h!\c`  
/3^XJb$Sa  
/* iymN|KdpaZ  
**Utility.java :aaX Y:<  
*/ |4 \2,M#  
package NetFox; 4r ~K`)/S'  
|ka/5o  
1W\wIj.  
public class Utility { ^VG].6  
1P1h);*Z  
|39,n~"o&  
public Utility() -P|claO0  
{ W^xO/xu1 /  
[xrsa!$   
^xNzppz`]C  
} [ 't.x=  
yhbU;qEG9  
//线程睡眠 Jq(;BJ90R  
public static void sleep(int nSecond) 5Rs#{9YE  
{ Z'2AsT  
try{ $57Q g1v  
Thread.sleep(nSecond); -ZSN0Xk  
} N6u>V~i  
catch(Exception e) S2E z}*plp  
{ ,.V<rDwN&  
e.printStackTrace (); ]dJ"_  
} ~&RrlFh  
} ?<W|Ya  
!vJ$$o6#  
//日志 rb4;@&  
public static void log(String sMsg) `o }+2Cb  
{ PMbZv%.,-  
System.err.println(sMsg); oOvQA W8`  
} un~`|   
u*I'c2m  
Q8h0.(#-  
public static void log(int sMsg) =. \hCgq  
{ %dW ;P[0  
System.err.println(sMsg); uQx/o ^  
} B|"i`{>  
} ! M CV@5$  
uo2k  
:*|Ua%L_  
/* 4TPdq&';C:  
**TestMethod.java Op]*wwI*h  
*/ n~\; +U  
package NetFox; FNF`Z  
]ilLed  
wf]?:'}  
public class TestMethod { ]4[%Sv6]G  
2#^g] o-N  
`Ji WS  
public TestMethod() Q Kr/  
{ ///xx/weblogic60b2_win.exe ^JMG'@x  
try{ |,oLZC Na  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T!y 9v5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yn]Sc<uK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Lhux~,EH  
fileFetch.start(); pKq[F*Lut  
} 4XER 7c  
catch(Exception e){e.printStackTrace ();} 1?|"33\03R  
u=v-,Tw  
>FOCdlJ#  
} Ot\[Ya''  
i?(cp["7  
Q"{Dijc%  
public static void main(String[] args) .(cpYKFX  
{ &}P#<"Fo8Q  
new TestMethod(); vw3[(_MV3_  
} PpG;5  
} uyk;]EYjHZ  
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