http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]43alf F#
} uYFMv=>j
for(int i=0;i<nEndPos.length-1;i++) d"#gO,H0
{ C%giv9a
nEndPos = nStartPos[i+1]; wYZT D*A2h
} u~s Sk
nEndPos[nEndPos.length-1] = nFileLength; iO!27y
} weNzYMf%
} "pt+Fe|@c;
Dt.0YKF
aSc{Ft/O
//启动子线程 6!P`XTTE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yiiyqL*E
for(int i=0;i<nStartPos.length;i++) T}C2e! _O
{ 7#QLtU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OnZF6yfN=3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a%Uw;6|{
nStartPos,nEndPos,i); }$o*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1hl]W+9
fileSplitterFetch.start(); B\\6#
} Lp_$?MCD.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `/z_rqJ0CL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k@#5$Ejc2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EE+`i%
nEndPos = " + nFileLength); UQ/qBbn
// fileSplitterFetch[nPos.length-1].start(); s[3e=N
$:Rn;
FY$fV"s
//等待子线程结束 gX[|;IZ0o
//int count = 0; 4|`Yz%'
//是否结束while循环 )h#]iGVN}
boolean breakWhile = false; h@=7R
puOC60zI
K*~]fy
while(!bStop) _@Y"$V]=Vt
{ n5|l|#c$N
write_nPos(); COR;e`%,
Utility.sleep(500); CdY8#+"
breakWhile = true; ]<1HM"D
!lAD q|$
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for(int i=0;i<nStartPos.length;i++) !BDUv(
{ 2K;#Evn'j
if(!fileSplitterFetch.bDownOver) Z1M>-[j)
{ iZaeoy
breakWhile = false; "NDxgJ%J35
break; X 7=fX~s
} *I0Tbc O
} J1bA2+5.*e
if(breakWhile) ?>af'o:
break; &-M]xo^
f|U0s
baee?6
//count++; +iy7e6P
//if(count>4) ` @8`qXg
// siteStop(); XAPYpBgm
} ~4\,&HH
VU|;:
Wqra8u#
System.err.println("文件下载结束！"); oBA`|yW{U
} D==Mb~
catch(Exception e){e.printStackTrace ();} 5!Bktgk.
} '_dzcN,z
K$H <}e3
piOXo=9H.
//获得文件长度 ,w{m3;]_%
public long getFileSize() UNDi_6Dy
{ XF}rd.K:
int nFileLength = -1; q_ %cbAcD
try{ $+cAg>
URL url = new URL(siteInfoBean.getSSiteURL()); lv]quloT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f6!D L<
httpConnection.setRequestProperty("User-Agent","NetFox"); 6 {}JbRNf
HG%Z"d
Tv5g`/e=Ej
int responseCode=httpConnection.getResponseCode(); mf' ]O,
if(responseCode>=400) ; dd Q/
{ S_v(S^x6
processErrorCode(responseCode); `Gd$:qV
return -2; //-2 represent access is error !g>.i`
} ]u#JuX
&.Q8Mi aT
|%1?3Mpn
String sHeader; fQ+\;iAU
cX:HD+wO
u=r`t(Z1H
for(int i=1;;i++) [Il~K
{ /\Z J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ""{|3XJe
//Utility.log(in.readLine()); Wkzs<y"
sHeader=httpConnection.getHeaderFieldKey(i); BI2; ex
if(sHeader!=null) ~>5#5!}@*
{ at|g%$%
if(sHeader.equals("Content-Length")) :B|Dr v
{ 7\XE,;4>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9b;A1gu
break; QvLZg
} -"Q-H/qh
} 9 [jTs3l:
else 5,pSg
break; 'Z&;uv,l
} e-5?p~>
} nmFC%p)4
catch(IOException e){e.printStackTrace ();} npp[@*~
catch(Exception e){e.printStackTrace ();} 9bJQT'<R
(\a6H2z8l
^YvB9XN
Utility.log(nFileLength); g~S)aU\:,
kforu!C
@kFu*"
return nFileLength; FP^{=0
} R?66b{O
DJ@|QQ
>TjJA#
//保存下载信息（文件指针位置） AoaN22
private void write_nPos() !@A#=(4R4
{ fP HLXg5s
try{ 7=XL!:P
output = new DataOutputStream(new FileOutputStream(tmpFile)); %7hB&[ 5
output.writeInt(nStartPos.length); J*fBZ.NO
for(int i=0;i<nStartPos.length;i++) ILwn&[A0
{ &<pKx!
// output.writeLong(nPos); aj\nrD1
output.writeLong(fileSplitterFetch.nStartPos); =~KsS}`1,
output.writeLong(fileSplitterFetch.nEndPos); !yOeW0/2[
} Avlz=k1*
output.close(); C\ZkGX
} !? 5U|
catch(IOException e){e.printStackTrace ();} qTQ!jN
catch(Exception e){e.printStackTrace ();} "xRBE\B
} oslJC$cy'
a`(a)9i
q2rUbU_A(
//读取保存的下载信息（文件指针位置） x]|+\1
private void read_nPos() m~hoE8C$
{ ULH0'@BJ
try{ TBrGA E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }MbH3ufC
int nCount = input.readInt(); U`|0 jJ
nStartPos = new long[nCount]; v%{.A)
nEndPos = new long[nCount]; %wptZ"2M
for(int i=0;i<nStartPos.length;i++) \C^;k%{LV
{ ra N)8w}-
nStartPos = input.readLong(); qmy%J
nEndPos = input.readLong(); z*$q8Z&7rg
} ,m<H-gwa
input.close(); dq1:s1
} #-% A[7Cdp
catch(IOException e){e.printStackTrace ();} X>YsQrK(ig
catch(Exception e){e.printStackTrace ();} JwnQ0 e
} RP5+d
gk[{2HgN
VdSv
private void processErrorCode(int nErrorCode) WKz> !E%
{ -u!FOD/
System.err.println("Error Code : " + nErrorCode); %M|,b!eF
} >>i@r@
A5'NGt
ORXm&z)
//停止文件下载 wa=uUM_4u^
public void siteStop() 3@Z#.FV~C[
{ #@@Mxr'F
bStop = true; _p-t<ytnh
for(int i=0;i<nStartPos.length;i++) vsWHk7 9
fileSplitterFetch.splitterStop(); hN2:d1f0
wkqX^i7ls
S [h];eM
} %?^6).aEK
} NLPkh,T:
//负责部分文件的抓取 :j')E`#
**FileSplitterFetch.java &!aAO(g
*/ <s5qy-
package NetFox; +Q=1AXe
`LAR@a5i
##Q/I|
import java.io.*; [.hyZ}B
import java.net.*; h_1T,f(
c gzwx
uXDq~`S
public class FileSplitterFetch extends Thread { g,o?q:FL
'0y9MXRT
"<_0A f]
String sURL; //File URL iRg7*MQu
long nStartPos; //File Snippet Start Position I):!`R.,
long nEndPos; //File Snippet End Position DypFl M*
int nThreadID; //Thread's ID %>-@K|:gS
boolean bDownOver = false; //Downing is over N>(g?A; Z+
boolean bStop = false; //Stop identical :ISMPe3'
FileAccessI fileAccessI = null; //File Access interface P&m\1W(
7XKY]|S,'
kg@>;(V&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }g#&Q0
{ t5)+&I2
this.sURL = sURL; Hqnxq
this.nStartPos = nStart; c|F[.;cR
this.nEndPos = nEnd; XNQAi (!GS
nThreadID = id; [V'QrcCF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^Q*atU
} OO?]qZa1
Xc"&0v%;#
[aI]y=v
public void run() lrfv+
{ B+^(ktZp@
while(nStartPos < nEndPos && !bStop) \AL f$88>@
{ h~{aGo
N]KxAttt
/%_OW@ ?
try{ '13ZX:
URL url = new URL(sURL); (b'B%rFO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [7_56\G4
httpConnection.setRequestProperty("User-Agent","NetFox"); |#6QThK
String sProperty = "bytes="+nStartPos+"-"; upj]6f"(
httpConnection.setRequestProperty("RANGE",sProperty); .h0b~nI>>
Utility.log(sProperty); &>e-(4Xu
[mEql,x3
U=hlu
InputStream input = httpConnection.getInputStream(); Y"-^%@|p
//logResponseHead(httpConnection); =+t^f
s"Pf+aTW
n,B,"\fw
byte[] b = new byte[1024]; >^XBa*4;Y
int nRead; P/EM :
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J|'7_0OAx
{ Fu&EhGm6
nStartPos += fileAccessI.write(b,0,nRead); L\y;LSTU
//if(nThreadID == 1) 6c^e\0q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /axIIfx-
} ui(^k $
s'kDk2r
%Y!Yvw^&P(
Utility.log("Thread " + nThreadID + " is over!"); /dv<qp
bDownOver = true; el:9wq
//nPos = fileAccessI.write (b,0,nRead); 5@^ dgq
} bdGIF'p%
catch(Exception e){e.printStackTrace ();} [D*UT#FM
} @as"JAN
} kcb.Wz~=
JyR/1 W
R+&jD;U{
//打印回应的头信息 Oft4-4$E
public void logResponseHead(HttpURLConnection con) "M|zv
{ hKzSgYxP=t
for(int i=1;;i++) tv!_e$CR
{ a'!zG cT
String header=con.getHeaderFieldKey(i); QtvYv!
if(header!=null) [HCAmnb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); detwa}h[0
Utility.log(header+" : "+con.getHeaderField(header)); f4L`.~b'hb
else TEDAb>
break; KiJT!moB
} O(+phRwJ
} }:Z#}8
H,N)4;F<c
=m5SK5vLKT
public void splitterStop() gn3jy^5
{ Nbp!teH6
bStop = true; ?B:a|0pf
} 'Ysx=
R'S0 zp6
hAHq\
} +[5.WC7J
I4&::y^C
F'hHK.tT
/* 8T(e.I
**FileAccess.java P;k0W>~k
*//文件访问(定位，写) z)HD`Ho
package NetFox; h,Q3oy\s1
import java.io.*; QR1{ w'c
d>{nQF;c
PssMTEf
public class FileAccessI implements Serializable{ 7EXI6jGJ|
)c8j}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 otk}y8
RandomAccessFile oSavedFile; U#3J0+!
long nPos; sP ls zC[
+|tC'gCnV
N5 $c]E
public FileAccessI() throws IOException =+AS/Jq
{ Vb9',a?#n
this("",0); .nyfYa+
} 1&e} ms
=C~/7N,lW]
b!)<-|IK
public FileAccessI(String sName,long nPos) throws IOException TC<@e<-%Sq
{ C:Hoq(
oSavedFile = new RandomAccessFile(sName,"rw"); Zfyo-Wk
this.nPos = nPos; qG<$Ajiin
oSavedFile.seek(nPos); &gjF4~W]
} qbv#I;
q`pP$i:
|^A;&//
public synchronized int write(byte[] b,int nStart,int nLen) .jj$Kh q]
{ QR>gt;
int n = -1; U*3uq7
try{ 5< ja3
oSavedFile.write(b,nStart,nLen); zL\OB?)5J
n = nLen; *6} N =Z
} hcyM6:}
catch(IOException e) /c,(8{(O
{ -=(!g&0
e.printStackTrace (); Dq)j:f#QM
} z`\F@pX%wC
|m2X+s9
DG?"5:Zd
return n; Ps 8%J;
} CP6LHkM9
Qci4J
{uHU]6d3qy
} =KR NvW
f aLtdQi
b?Ki;[+O
/* {Lm~r+ U
**SiteInfoBean.java &\Amn?Iq
*/ 8HP6+c%
package NetFox; 6,9o>zT%H
~j<+k4I~
3"P }n
public class SiteInfoBean { Yh>]-SCw
1CHeufQ
Ry|!pV
private String sSiteURL; //Site's URL 8KRba4[
private String sFilePath; //Saved File's Path f/V 2f].
private String sFileName; //Saved File's Name 7P9=)$(EH
private int nSplitter; //Count of Splited Downloading File ldp%{"ZZ
L@gWzC~?Q
LU9A#
public SiteInfoBean() "70WUx(\t
{//nSplitter的缺省值为5 W>O~-2
//default value of nSplitter is 5 gmm|A9+tv
this("","","",5); W]nSR RWco
} |<GDUwC_;
VP6ZiQ|
yUp,NfS]o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |M+<m">E
{ rs~wv('
sSiteURL= sURL; ObiT-D?)g
sFilePath = sPath; g]c6&Y,#
sFileName = sName; {\(L%\sV@
this.nSplitter = nSpiltter; ]GRWnif
3.qTLga|}
lgb?)=
} 3%E74 mOcD
y>aZXa
.<Zy|1 4
public String getSSiteURL() c.j$9=XLBG
{ ,JEFGI{
return sSiteURL; D)d~3`=#
} >>5NX"{
;W^o@*i{>
#cCL.p"]
public void setSSiteURL(String value) u5Ftu?t
{ >2Kh0rIH
sSiteURL = value; VL*ovD%-
} Et/&^&=\-
!Uq^7Mw
@0SC"CqM
public String getSFilePath() TEaJG9RU>v
{ uNHF'?X
return sFilePath; R>(@ZM&
} 1Y]TA3:
J52 o g4l
0gfA#|'
public void setSFilePath(String value) 7=DjI ~
{ Yk5}`d!:
sFilePath = value; 48*Do}l]
} LH@j8YB5u
Yx>"bv
A$a1(8H
public String getSFileName() n2fbp\I
{ <Ce2r"U1e
return sFileName; $]A/ o(
} !OuWPH. :
&Y^WP?HS
yfC^x%d7G
public void setSFileName(String value) 1hziXC0WY
{ th&[Nt7
sFileName = value; ;asP4R=
} QJ7L7S
l!g]a2x*
$.[#0lCI
public int getNSplitter() kVy\b E0o
{ a@0BBihz
return nSplitter; 6%VV,$p
} gw}Mw
~mR'Q-hi<
Z>^pCc\lH
public void setNSplitter(int nCount) `2PLWo
{ Ed ,D8ND
nSplitter = nCount; 4M^G`WA}t9
} 1 %,a =,v
} b/Xbs0q
ME=/|.}D<
Vl2XDkhq
/* Rh>}rGvCUN
**Utility.java Ey4z.s'-l
*/ V@\%)J'g
package NetFox; @`,1:
-%I2[)F<
B0ndcB-
public class Utility { QQV~?iW{~
izx#3u$P
X 51Yfr
public Utility() iT)z_
{ T0]*{k(FR
]7/ b/J
eVM/uDD
} dF~8XYo
>~Qr
//线程睡眠 /mK?E5H'r1
public static void sleep(int nSecond) &zuG81F6
{ KR%{a(V;7
try{ '_$uW&{NI
Thread.sleep(nSecond); h)Ff2tX
} !0dNQ[$82
catch(Exception e) A+UU~?3y
{ Vo"RO$%ow*
e.printStackTrace (); ^'ryNa;"
} Q pmsOp|
} s\P2Bp_{
Ck/F9(
//日志 G7CG~:3h+
public static void log(String sMsg) ]$,UPR/3
{ UAyC.$!
System.err.println(sMsg); m{7(PHpw
} Ogp"u b8
\~5C7^_
S*sT] J`!
public static void log(int sMsg) !Lh^oPT"I
{ E.U_W
System.err.println(sMsg); O/!bG~\Y
} ]7rj/l$u
} 8zBWIi
3ux0Jr2yT
:hI@AA>g
/* QzAK##9bfa
**TestMethod.java =dx1/4bZl|
*/ ykFJ%sw3X
package NetFox; %/rMg"f:
V._(q^
Ii:>xuF&
public class TestMethod { j6g[N4xr
A mwa)
{H{X[p8
public TestMethod() #-GJ&m8
{ ///xx/weblogic60b2_win.exe XduV+$03
try{ E(i[o?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EFc-foN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g9Yz*Nee<
SiteFileFetch fileFetch = new SiteFileFetch(bean); f +hjC
fileFetch.start(); 8Y#\xzod
} "{D|@Bc
catch(Exception e){e.printStackTrace ();} h48SItY
E!O\87[
{$1J=JbE
} >G'SbQ8
jU5}\oP@
Q(o!iI:Gts
public static void main(String[] args) g38&P3/
{ ,p9i%i
new TestMethod(); I=!rbF;Z
} l]]l
} mP(kcMT"
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