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)); LXxl?D
} lIl9ypikg
for(int i=0;i<nEndPos.length-1;i++) 7.|S>+Q
{ `Kp}s<
nEndPos = nStartPos[i+1]; s5.k|!K
} Wf1-"Q
nEndPos[nEndPos.length-1] = nFileLength; -s~p}CQ.
} <4NQL*|>
} ZOHRUm
bX{PSjD
g =\13#F
//启动子线程 J~2CD*v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m){&:Hs
for(int i=0;i<nStartPos.length;i++) }rxFS <j
{ M=Is9)y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N[{]iQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ja=N@&Z#
nStartPos,nEndPos,i); :wCC^Y]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _6I>+9#C
fileSplitterFetch.start(); SD I,M
} CU !.!cZ{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fW[.r==Kf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EQ~I'#m7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8)`5P\
nEndPos = " + nFileLength); #ZwY?T x
// fileSplitterFetch[nPos.length-1].start(); (QhAGk&lu
]eL~L_[G\
%>NRna
//等待子线程结束 ndt8=6p
//int count = 0; e)og4
//是否结束while循环 % NwoU%q
boolean breakWhile = false; Ug`
%J3lK]bv(
Nuo<` 6mV@
while(!bStop) Es,0'\m&
{ %,E7vYjT%
write_nPos(); fa.f(c
Utility.sleep(500); L%4tw5*N
breakWhile = true; C$0ITw
.?7So3
t9n'!
for(int i=0;i<nStartPos.length;i++) <sF!]R&4
{ lZ+/\s,]|
if(!fileSplitterFetch.bDownOver) _4S7wOq5
{ BC&^]M
breakWhile = false; ix+x3OCip
break; 33S`aJ
} @) ]t8(
} ~l@%=/m
if(breakWhile) a\|X^%2g
break; B)(w%\M4^
"URVX1#(r
gGD]t;<u
//count++; ;W =by2x*
//if(count>4) 3pzOt&T|w
// siteStop(); r6/<&1[
} s UvKA0
,7/\&X<`B
4v i B=>
System.err.println("文件下载结束！"); ;+!xZOmm
} sd7Y6?_C
catch(Exception e){e.printStackTrace ();} i@%L_[MtA
} $jDD0<F.#
;vZ*,q6
ug>]U ~0
//获得文件长度 E,Dlaq
public long getFileSize() )z|_*||WU^
{ J\9jsx!WQ
int nFileLength = -1; .|tQ=l@I
try{ iNMLYYq]l
URL url = new URL(siteInfoBean.getSSiteURL()); *GB$sXF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8cequAD
httpConnection.setRequestProperty("User-Agent","NetFox"); g8B&u u #
P/HHWiD`D
],WwqD=
int responseCode=httpConnection.getResponseCode(); k0R,!F
if(responseCode>=400) [)B@
{ puk4D
processErrorCode(responseCode); _LLW{^V
return -2; //-2 represent access is error *YMXiYJR
} YlxUx
Gf!t< =T
%Gnd"SGs
String sHeader; nT(!HDH
d;IJ0xB+by
F12S(5Z0%
for(int i=1;;i++) 6i55Ja
{ 4h[2C6 \+`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WIhIEU7/
//Utility.log(in.readLine()); _q2`m
sHeader=httpConnection.getHeaderFieldKey(i); 3BuD/bs
if(sHeader!=null) =2Pz$q*ub
{ MX%|hIOpr
if(sHeader.equals("Content-Length")) }"!6Xm
{ ,<IL*=a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pvK \fSr
break; 1j_aH#Fz:
} }C9VTJs|
} &n,xGIG
else 0fEZD$
break; xow6@M,
} dpl"}+
} Vu^Q4Z
catch(IOException e){e.printStackTrace ();} 2*b#+b
catch(Exception e){e.printStackTrace ();} !^rITiy
gt(X!iN]
Ss*LgK_
Utility.log(nFileLength); m(Pz7U.Q
3g4vpKg6c
*=r@vQ
return nFileLength; d{(s-
} -sruxF
_S[Rvb1e
x`b~ZSNJ%
//保存下载信息（文件指针位置） `Nxo0Q
private void write_nPos() 6T5A31 Q
{ %`8KG(F^
try{ AiR%MD
output = new DataOutputStream(new FileOutputStream(tmpFile)); c=uBT K*
output.writeInt(nStartPos.length); Zi15wE
for(int i=0;i<nStartPos.length;i++) 1D#T+t`[
{ KR+aY.
// output.writeLong(nPos); 4C2>0O<^s
output.writeLong(fileSplitterFetch.nStartPos); @Wlwt+;fT
output.writeLong(fileSplitterFetch.nEndPos); i:NJ>b
} 1`7]C+Pv
output.close(); +"*l2E]5
} 0DW'(#`
catch(IOException e){e.printStackTrace ();} l#<}|b
catch(Exception e){e.printStackTrace ();} BHiw!S<
} S0X.8Bq
^$T!@+:
.F=<r-0
//读取保存的下载信息（文件指针位置） MC[`<W)u
private void read_nPos() H-PW(
{ 3tx0y
try{ !kjr>:)x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `:B
int nCount = input.readInt(); kfG65aa>_
nStartPos = new long[nCount]; [7ek;d;'t
nEndPos = new long[nCount]; h|Teh-@A5
for(int i=0;i<nStartPos.length;i++) _ cHV3cz
{ Dg];(c+/
nStartPos = input.readLong(); 96([V|5K
nEndPos = input.readLong(); e2_r0I^C
} %$!R]B)
input.close(); 9Le/'ovq
} v\r7.l:hf
catch(IOException e){e.printStackTrace ();} 8kn]_6:3i
catch(Exception e){e.printStackTrace ();} HCn]#
} `eA&C4oFOO
SFXfo1dqH
[f0oB$
private void processErrorCode(int nErrorCode) )e <! =S
{ r5fz6"
System.err.println("Error Code : " + nErrorCode); :p*ojl|
} dcc%G7w
>(1_Dn\
^~*[~
//停止文件下载 +p%5/smfs
public void siteStop() #xJGuYdv
{ R)DNFc:
bStop = true; 8 MACbLY
for(int i=0;i<nStartPos.length;i++) WPh |~]by<
fileSplitterFetch.splitterStop(); m}'t'l4 c
UHsrZgIRYT
o )}<
} ytcG6WN3
} Ty,)mx){)
//负责部分文件的抓取 _|5FrN
**FileSplitterFetch.java ~_^o?NE,
*/ Yqz[sz5+m
package NetFox; ky lrf4=
^|hRu{QW
KTAe~y
import java.io.*; %NAFU/&
import java.net.*; X6"^:)&1M
yADN_
(w@MlMk
public class FileSplitterFetch extends Thread { eL$U M
Kr}M>hF+|
c#4L*$ViF
String sURL; //File URL B$[%pm`'2
long nStartPos; //File Snippet Start Position $y]||tX
long nEndPos; //File Snippet End Position ?}lpo; $
int nThreadID; //Thread's ID O%q;,w{prW
boolean bDownOver = false; //Downing is over J#OE}xASoA
boolean bStop = false; //Stop identical "}~i7NBB
FileAccessI fileAccessI = null; //File Access interface Hr8$1I$=
SpTORR8
XCi]()TZ_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j*Wh;I+h
{ '2qxcco
this.sURL = sURL; -aeo7C
this.nStartPos = nStart; l1|,Lr
this.nEndPos = nEnd; S&)) 0d
nThreadID = id; +qW w-8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qzbkxQu]g
} ?GD?J(S
]OCJ~Zw
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public void run() Hpo?|;3D5
{ }+RF~~H/
while(nStartPos < nEndPos && !bStop) oJ;O>J@c
{ {uQ)p=
"VVR#H}{
,IZxlf%
try{ gBiQIhz
URL url = new URL(sURL); r(2'0JQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :R*^Izs=
httpConnection.setRequestProperty("User-Agent","NetFox"); UE$[;Zg
String sProperty = "bytes="+nStartPos+"-"; !7a^8
httpConnection.setRequestProperty("RANGE",sProperty); &)f++(i
Utility.log(sProperty); /KvPiQ%
m+8b2H:V
xS\QKnG.
InputStream input = httpConnection.getInputStream(); W<hdb!bE
//logResponseHead(httpConnection); |I^Jn@Mq:
9xS`@ "`
;>8TNB e!
byte[] b = new byte[1024]; +(P43XO08
int nRead; !DUg"o3G>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m ?"%&|
{ /zP)2q^
nStartPos += fileAccessI.write(b,0,nRead); G mUs U{
//if(nThreadID == 1) 41Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); huD\dmQ:]
} Rc.<0#
}GNH)-AG)$
n; '~"AG)
Utility.log("Thread " + nThreadID + " is over!"); 'GdlqbX(%
bDownOver = true; WUK.>eM0
//nPos = fileAccessI.write (b,0,nRead); A%8`zR
} 4Z p5o`*g2
catch(Exception e){e.printStackTrace ();} P;o>~Y>x
} ].T;x|
} 5!Mp#lO
C`T5d
= Vr[V@
//打印回应的头信息 TKBK3N
public void logResponseHead(HttpURLConnection con) 2yO)}g FJ
{ HNUR6H&Fta
for(int i=1;;i++) w7?9e#>Z
{ ]4Yb$e`
String header=con.getHeaderFieldKey(i); V5@[7ncVf
if(header!=null) ue:P#] tx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vKOn7
Utility.log(header+" : "+con.getHeaderField(header)); d*:qFq_
else Olh%"=*;
break; wQuaB6E
} 0]w[wc <
} 1Y"qQp
Ri6 br
=ZIFS
public void splitterStop() eV=sDx
{ ?,e:c XhE2
bStop = true; Bv]wHPun
} Y},GZ^zqy
G`lhvpifG
n~i4yn=
} 8jGoU9
`ip69 IF2*
%f(.OR)6{
/* |oi49:NXn
**FileAccess.java v6Wf7)d/1
*//文件访问(定位，写) VRP.tD
package NetFox; [>9"RzEl
import java.io.*; !4.^@^L|\
"8dnFrE
[Et\~'2w8=
public class FileAccessI implements Serializable{ Z5a@fWU
1% %Tm"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jy|xDQ
RandomAccessFile oSavedFile; ssbyvzQ
long nPos; aNU%OeQA
6}lEeMRW
Q>g$)-8
public FileAccessI() throws IOException 8/$iCW
{ P2RL\`<"
this("",0); &_9eg
} ]H'82a
ddhTri'f
l8lR5<
public FileAccessI(String sName,long nPos) throws IOException .Tqvy)'
{ wTbIS~!gF
oSavedFile = new RandomAccessFile(sName,"rw"); %= ;K>D
this.nPos = nPos; :@A;!'zpL
oSavedFile.seek(nPos); OWfj<#}t+
} `;2`H, G'
Xn'>k[}<k
19`0)pzZ*P
public synchronized int write(byte[] b,int nStart,int nLen) JN-8\L
{ ' *C)S
int n = -1; (\Zo"x;(
try{ cU[pneY
oSavedFile.write(b,nStart,nLen); I T2sS6&R
n = nLen; b>._ r&.
} n:)Y'52}
catch(IOException e) {X"]92+
{ dg8\(G
e.printStackTrace (); > o`RPWs
} @CUDD{1o
<"%h1{V
%4K#<b"W
return n; %d\+(:uu/
} A8Y~^wn
T`[ZNq+${
)`7h,w J[1
} 5R G5uH/-<
hrt-<7U
u#|Jl|aT
/* _Hj,;Z
**SiteInfoBean.java Oip..f0
*/ %=eD)p7l-
package NetFox; 3iL&;D
iiB$<b.((I
rWmi 'niu
public class SiteInfoBean { M_I\:Q
.1lc'gu5y
l6Bd<tSH
private String sSiteURL; //Site's URL Bn:sN_N
private String sFilePath; //Saved File's Path pz=Wq4l
private String sFileName; //Saved File's Name P*sCrGO%
private int nSplitter; //Count of Splited Downloading File ?C\9lLX
B6&Mtm1
K#m o+n5-;
public SiteInfoBean() V#KM~3e
{//nSplitter的缺省值为5 H@2+wr)$}
//default value of nSplitter is 5 1D]wW%us
this("","","",5); ?&_\$L[
} ~;Kl/Z
IW*.B6Hw8
j pV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) syvi/6
{ 1!#ZEI C
sSiteURL= sURL; Pw.+DA
sFilePath = sPath; xbA2R4|
sFileName = sName; 3|3lUU\I
this.nSplitter = nSpiltter; }"tYb6*
XE\bZc
]0E-lD0J
} Zv7)+Q
=v9;HPiO
SBt: `,
public String getSSiteURL() inrL'z
{ '5\1uB PKW
return sSiteURL; aR $P}]H
} K.Z{4x=0
VUy 1?n
7]bqs"t
public void setSSiteURL(String value) 0T;WN$W|
{ &Y$rVBgQ
sSiteURL = value; H\vO0 <X
} 5H2|:GzUc
)G&OX
V"73^
public String getSFilePath() *^ BE1-
{ yD"sYT
return sFilePath; Mk;j"ZDF
} 0}N^l=jQ
Fsh-a7Qp
plAt +*&
public void setSFilePath(String value) cPSu!u}D
{ EbHeP
sFilePath = value; ,5:86'p
} +0DIN4Y(4
~JiA
Fy^\Uw
public String getSFileName() uv!/DX#
{ jL<.?HE
return sFileName; D![Twlll
} DGnswN%n1
Hn)=:lI
RZjR d
public void setSFileName(String value) sMK/l @7
{ B^{DCHu/
sFileName = value; sYzG_*)
} &V L<Rx
`Ii>wb
.wywO|
public int getNSplitter() >xN^#$ng}
{ gUcE,L
return nSplitter; CgWj9 [
} Pcc%VQN
&~8}y+z
qsp,Usu/
public void setNSplitter(int nCount) E7D DMU
{ -~g3?!+Hb
nSplitter = nCount; ;DTNw=
} [B[J%?NS
} PZs
Z:Wix|,ONS
TH-^tw
/* qCMcN<:>
**Utility.java dGg+[?
*/ s0u$DM2
package NetFox; gqhW.e}]
+Muyp]_
;&!l2UB%
public class Utility { =@'"\ "Nh
G+}LLm.wX
=[,adB
public Utility() jn[a23;G)
{ iX28+weH
':=C2x1d|
t65!2G"<
} |w5#a_adM
1NTe@r!y
//线程睡眠 *=8)]_=f
public static void sleep(int nSecond) C{D2mSS
{ ?/\;K1c p
try{ C"}x=cK
Thread.sleep(nSecond); xl3U
} |Yx8Ez
catch(Exception e) :1iw_GhJf
{ O]>Or3oO
e.printStackTrace (); km^AX:r1
} z(ajR*\#
} B@4#y9`5
I'gnw~
//日志 x[X.// :
public static void log(String sMsg) D7@10;F}[
{ ^V:YNUqp#
System.err.println(sMsg); &Fi8@0Fh
} Um~jp:6p
}MX`WW0\]Z
~?p > L
public static void log(int sMsg) ms$o,[
{ %wO~\:F8
System.err.println(sMsg); X}ZOjX!
} 1li`+~L F
} (#:Si~3
;9~z_orNQZ
}yw\+fc
/* {*2A%}S
**TestMethod.java U{x'@/Ld
*/ kB 2bT}
package NetFox; sw&Qks?V
v6GWD}HH,
u32<=Q[
public class TestMethod { zb<+x(0y"
&$=F$
kK(633s
public TestMethod() )sQbDA|p
{ ///xx/weblogic60b2_win.exe Ub"\LUu
try{ 8c~H![2u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >eXNw}_j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |LQmdgVr$
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9.R_=
fileFetch.start(); 'fB`e]_
} yF:fxdpw
catch(Exception e){e.printStackTrace ();} X>CYKRtb
F,D&
mB\5bSFY`
} u,C-U!A
,ToED
C{Fo^-3
public static void main(String[] args) sqy5rug
{ RPrk]<<1
new TestMethod(); o 2DnkzpJ
} 1ID!rxE
} 6QV/8IX
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