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)); ~FCkr&Ky3
} u2\QhP 9
for(int i=0;i<nEndPos.length-1;i++) apy9B6%PJ+
{ ;@/^hk{A
nEndPos = nStartPos[i+1]; iX (<ozH
} ZMa@/\pf1
nEndPos[nEndPos.length-1] = nFileLength; x6N)T4J(
} |0^~S
} M it3q
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.! 'SG6 q
//启动子线程 {/ef`MxV }
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y-YlQ^
for(int i=0;i<nStartPos.length;i++) ,v\^efc:%
{ |f67aN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1xBgb/+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GoSdo
nStartPos,nEndPos,i); 7H=V|Btnc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9:9gam
fileSplitterFetch.start(); p#;I4d G
} :}0>IPW-V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ; ,9:1.L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9^+8b9y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Bl$Hg,in-
nEndPos = " + nFileLength); "($"T v2
// fileSplitterFetch[nPos.length-1].start(); ;+;%s D
P z< \q;
"WF@T
//等待子线程结束 (Y!{ UNq5
//int count = 0; +YD_ L
//是否结束while循环 0)Nu
boolean breakWhile = false; +%sMd]$,n
!94qF,#1
Gv\39+9=
while(!bStop) i0q<,VSl$_
{ ! mb<z^>5
write_nPos(); ^jYE4gHM
Utility.sleep(500); " i!Xiy~
breakWhile = true; cZR9rnZT
4(nwi[1Y
@h=r;N#/`P
for(int i=0;i<nStartPos.length;i++) |X47&Y
{ %^KNY ;E
if(!fileSplitterFetch.bDownOver) [%LIW%t|
{ 5.M82rR;~
breakWhile = false; 2e?a"Vss
break; T"_f9?
} 3q-Xj:FP
} 9 `+RmX;m
if(breakWhile) i&mt-
break; 'f_[(o+n
8{4SaT.-Rm
,II-:&H
//count++; *G&3NSM-
//if(count>4) i K,^|Q8
// siteStop(); ]iezwz`'
} r7FFZNs!
\DMZ M
qbx}9pp}g
System.err.println("文件下载结束！"); 89Ch'D
} ioT+,li
catch(Exception e){e.printStackTrace ();} }}b &IA#
} +wIv|zj9
[cso$Tv
6^vz+oN
//获得文件长度 HRg< f= oz
public long getFileSize() 9M;k(B!
{ 2A&Y})D
int nFileLength = -1; b|Sjh;
try{ ?v,4seRuz
URL url = new URL(siteInfoBean.getSSiteURL()); S;tv4JY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lvp8{]I<
httpConnection.setRequestProperty("User-Agent","NetFox"); M$Or|HTG
fx=HKt
l1UN.l'p
int responseCode=httpConnection.getResponseCode(); ~O8Xj6
if(responseCode>=400) ;d<RPVE:
{ sjj,q?
processErrorCode(responseCode); s;W1YN
return -2; //-2 represent access is error L %20tm
} UPcx xtC
{?uG] G7
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String sHeader; $s<bKju
AGMrBd|J{
.azA1@V|
for(int i=1;;i++) M0K+Vz=
{ hQ_gOI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !SAR/sdXf
//Utility.log(in.readLine()); St|B9V?eEB
sHeader=httpConnection.getHeaderFieldKey(i); qr'P0+|~5
if(sHeader!=null) v=J[p;H^H
{ eh /QFm 4
if(sHeader.equals("Content-Length")) >5MHn@
{ Oi4y~C_Xd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e)#f`wM
break; NR.YeKsBq
} -F&*>?I
} lG R6S
else chszP{-@X
break; D:#e;K
} ' }T6dS
} wvz_)bN~A
catch(IOException e){e.printStackTrace ();} cr>"LAi
catch(Exception e){e.printStackTrace ();} a&C}'e"
&O\$=&, h
JW9U&Bj{
Utility.log(nFileLength); &Xp<%[:
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9-hVlQ~|
return nFileLength; EZ)$lw/!J
} wq>0W4(
I%tJLdL
:>o2UH
//保存下载信息（文件指针位置） !8}x6
private void write_nPos() 0u=FlQ }h
{ k|;[)gE
try{ o l8|
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rdl^-\BV
output.writeInt(nStartPos.length); rssn'h
for(int i=0;i<nStartPos.length;i++) @f%q ,:
{ hx:"'m5
// output.writeLong(nPos); k*k 9hv?
output.writeLong(fileSplitterFetch.nStartPos); |YWX.-aeo
output.writeLong(fileSplitterFetch.nEndPos); [fIElH<
} g3kF&+2i
output.close(); $[M5Vv
} YdF\*tZ
catch(IOException e){e.printStackTrace ();} *,#T&M7D
catch(Exception e){e.printStackTrace ();} [*z`p;n2D
} o}6d[G>
B`/p[U5
,#hx%$f}d
//读取保存的下载信息（文件指针位置） ZE4xF8
private void read_nPos() $94l('B6H
{ ZuVes?&j
try{ <69Uq8GI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); by@}T@^\
int nCount = input.readInt(); 3fhlMOm
nStartPos = new long[nCount]; =plU3D2
nEndPos = new long[nCount]; v6*8CQ+
for(int i=0;i<nStartPos.length;i++) m)"wd$O^w
{ Pj7n_&*/
nStartPos = input.readLong(); "Oq>i9v;|$
nEndPos = input.readLong(); gvy c(d
} D.Z4noMA6
input.close(); t`eUD>\
} C?fa-i0l^
catch(IOException e){e.printStackTrace ();} xSL%1>MrN
catch(Exception e){e.printStackTrace ();} lbnH|;`$]m
} &'A8R;b}-?
+X4/l"|
m6YDyQC
private void processErrorCode(int nErrorCode) obtXtqew
{ oa:30@HSb
System.err.println("Error Code : " + nErrorCode); ?)mM]2%%
} ?n9?`8a#
:}3;z'2]l
[RFF&uy
//停止文件下载 x$;kA}gy
public void siteStop() g4NbzU[I
{ $i.)1.x
bStop = true; jyFXAs2
for(int i=0;i<nStartPos.length;i++) /qObXI
fileSplitterFetch.splitterStop(); 1jkMje
.vk|aIG
az;o7[rI^
} =.yKl*WV{
} %2z]2@
//负责部分文件的抓取 `AcT}.u
**FileSplitterFetch.java W=ar&O~}n
*/ ;=F]{w]$+
package NetFox; AD4Ot5
*Rj(~Q/t
!/wR[`s9w
import java.io.*; 7FvtWE*
import java.net.*; ar[*!:!
=6^phZ(
tZqy \_G
public class FileSplitterFetch extends Thread { fLR\@f
a534@U4,
f]37Xl%I
String sURL; //File URL ^Uq"hT(41
long nStartPos; //File Snippet Start Position 18];fC
long nEndPos; //File Snippet End Position EH~XN9b
int nThreadID; //Thread's ID HL34pmc
boolean bDownOver = false; //Downing is over CH4 ~9mmE
boolean bStop = false; //Stop identical $pGdGV\H
FileAccessI fileAccessI = null; //File Access interface o<\9OQ0
gy6Pf4Yo
1GI/gc\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k.("<)
{ *9I/h~I
this.sURL = sURL; fsH=2p
this.nStartPos = nStart; z-;2)RkV2
this.nEndPos = nEnd; kCVA~%d7
nThreadID = id; <yz&> +9,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +c-?1j
} CF_pIfbaf
4;.y>~z
iQJ[?l`
public void run() 0tyS=X;#e
{ OD`?BM
while(nStartPos < nEndPos && !bStop) )%D>U
{ wR*>9LjeG
6im!v<1Qx
^oT!%"\
try{ o:8*WCiqrN
URL url = new URL(sURL); ZQ'bB5I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .uwD;j +#
httpConnection.setRequestProperty("User-Agent","NetFox"); !i77v, (#|
String sProperty = "bytes="+nStartPos+"-"; +8~C&K:
httpConnection.setRequestProperty("RANGE",sProperty); sm>5n_Vw
Utility.log(sProperty); Vi o ~2
[mJmT->
`am]&0g^+(
InputStream input = httpConnection.getInputStream(); ubZcpqm?Q
//logResponseHead(httpConnection); /2#1Oi)o
*D6X&Hg&5
rj> _L
byte[] b = new byte[1024]; 8O_0x)X
int nRead; 5y%-K=d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hd9vS"TN]
{ 8,m3]Lg
nStartPos += fileAccessI.write(b,0,nRead); %}0B7_6B+@
//if(nThreadID == 1) JLFZy\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qTD^Vz V
} Kfl#78$d
Z<^TO1xs9B
z-X_O32
Utility.log("Thread " + nThreadID + " is over!"); e )?~
bDownOver = true; q|_t=YM@
//nPos = fileAccessI.write (b,0,nRead); ]H_|E
} TEYn^/n~
catch(Exception e){e.printStackTrace ();} H 6~6hg
} |NoTwK
} gvl3NQQ%t
r#;GVJR6
Obb"#W@3
//打印回应的头信息 do>,ELS+m
public void logResponseHead(HttpURLConnection con) L/sMAB
{ p ! _\a
for(int i=1;;i++) &)y$XsSMW
{ 4UV<Q*B\F
String header=con.getHeaderFieldKey(i); )%T<Mw2u
if(header!=null) M7JQw/,xs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KqNbIw*sR
Utility.log(header+" : "+con.getHeaderField(header)); Sh+$w=vC
else ;"N4Yflz
break; DbH"e
} LqA&@
} \)'o{l&
+dgHl_,i
W-UMX',0zS
public void splitterStop() 0/@ ^He8l
{ IVblSiFF
bStop = true; -4IHs=`;I
} /suW{8A(E
2S^:fm}
rrL gBeQa
} Un[ 0or
U:1cbD7|3
Gi=s|vt
/* t6JM%
**FileAccess.java $/p/9 -
*//文件访问(定位，写) k~,({T<
package NetFox; ! O~:
import java.io.*; 2/ES.>K!.
<RaM@E
UG5AFZ\
public class FileAccessI implements Serializable{ ;p_@%*JAx
QO&{Jx.^[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _hz}I>G@B
RandomAccessFile oSavedFile; V~%C me
long nPos; a#L:L8T;j
5zf bI
4 [K"e{W3
public FileAccessI() throws IOException o,D7$WzL
{ <jwQ&fm)/R
this("",0); "7X[@xX@
} {k"t`uo_
9>I&Z8J$M
(O@fgBM
public FileAccessI(String sName,long nPos) throws IOException uZ/XI {/
{ g;n6hXq4
oSavedFile = new RandomAccessFile(sName,"rw"); kQt#^pO)
this.nPos = nPos; ><Awk~KR
oSavedFile.seek(nPos); r|,_qNrw
} dvX[,*wz
q@(MD3OE
mN&B|KWU
public synchronized int write(byte[] b,int nStart,int nLen) K275{ydN
{ %p t^?
int n = -1; w28&qNha
try{ Dm+[cA"I
oSavedFile.write(b,nStart,nLen); *&nIxb60b{
n = nLen; BJNZH#"
} J\%SAit@
catch(IOException e) :I!}ZD+Z
{ [0M`uf/u
e.printStackTrace (); oH]_2[ !
} L#6!W
^1mnw@04
N}\%r&KR=
return n; .X](B~\!
} Qt+i0xd
b2 5.CGF
\Aq$h:<
} Zb4+zps^-
m<liPl uv
L4t(Y7
/* ?;xL]~Q~1
**SiteInfoBean.java epm ~
*/ WZ6'"Cz`
package NetFox; kuI$VC
#i'wDvhol
vKFEA7
public class SiteInfoBean { [fZhfZ)<
;#XF.l,u
<To$Hb,NP
private String sSiteURL; //Site's URL F6Ne?[b
private String sFilePath; //Saved File's Path %)#yMMhR
private String sFileName; //Saved File's Name >z|bQW#2
private int nSplitter; //Count of Splited Downloading File zb,YYE1
i[4t`v'Dk
jb83Y>
public SiteInfoBean() K3.z>.F'h
{//nSplitter的缺省值为5 k@ So l6
//default value of nSplitter is 5 `P/87=h
this("","","",5); ~oX`Gih
} U)6Ew4uRxV
\ !qe@h<
$g&_7SJ@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yW]>v>l:Eg
{ Hg04pZupN
sSiteURL= sURL; oH"VrS 6
sFilePath = sPath; E0*62OI~O
sFileName = sName; ecMpU8}rR
this.nSplitter = nSpiltter; Ie7S'.Lmq
q${+I(b,
n3_|#1Qu
} 49tJ+J-N
A)80qx:
7TB&Q*Zf
public String getSSiteURL() cMoBYk
{ W_bA.zT{
return sSiteURL; =J0r,dR
} 2= )V"lR\
J 7HOSFwXn
RHu4cK!5
public void setSSiteURL(String value) eHc.#OA&
{ Im"8+756
sSiteURL = value; Fgw$;W
} 5 D[`nU}
q-r5zGI
=6d'/D#J
public String getSFilePath() /}Ct2w&<k
{ Q;k D Jo
return sFilePath; @g]>D
} S76xEL
l<UA0*t
4bq+(CI6
public void setSFilePath(String value) \F9HsR6
{ [H=l#W@
sFilePath = value; <Q@{6
} ?8ady% .ls
H8A=]Gq
h3(B7n7
public String getSFileName() us )NgG
{ $AF,4Ir-b+
return sFileName; FPkig`(3
} `{&l _
I#-T/1N
~)#xOE}
public void setSFileName(String value) yHnN7&
{ 0Ci:w|J
sFileName = value; =zRjb>
} f!bGH-.r5
mMtva}=*
6.M!WK{+
public int getNSplitter() ch)#NHZ9F
{ DcsQ6
return nSplitter; ',s{N9
} 6)1xjE#
tg;AF<VI
q)!G5j3
public void setNSplitter(int nCount) ;5:3 =F>ao
{ ksV^Y=]
nSplitter = nCount; t]6 4=
} )%bY2 pk
} U(\ ^!S1
l-q.VY2
/jN&VpDG
/* zJTSg
**Utility.java Dw&_6\F@
*/ t Z]b0T(e
package NetFox; ,%]xT>kH
fH 0&Wc3yC
WZf}1.Mh*
public class Utility { |$`I1
| (: PX
,S7M4ajVZB
public Utility() aq$adPtu
{ ^fhkWx4i
.]BJM?9
LLJsBHi-
} 9m}c2:p
=~ ="#
//线程睡眠 aZL FsSY
public static void sleep(int nSecond) .!Os'Y9[,
{ G;;iGN
try{ 4fau 9bW
Thread.sleep(nSecond); |r/4 ({n
} \q:PU6q
catch(Exception e) }tPI#[cfK
{ F}4jm,w
e.printStackTrace (); gg QI
} CDGN}Q2_
} oT[8Iu
qW t 9Tr
//日志 BZRC0^-C@
public static void log(String sMsg) r&D&xsbQ
{ Gu\lV c
System.err.println(sMsg); QW6\~l 4
} 6Ej@;]^^-
xyRZ v]K1
Z{ b($po
public static void log(int sMsg) ?iaD;:'qE
{ gfU!sYZ
System.err.println(sMsg); Hh0a\%!
} ['_G1_p
} Hbi2amfBu
~ H $q
Uv(Uj3D
/* ^6Y:9+
**TestMethod.java '>"-e'1m(
*/ 5:~BGK&{Y
package NetFox; l;'c6o0e
c!=^C/5Ee
&HYs^|ydrr
public class TestMethod { L }&$5KiwV
wEJ?Y8
/]"2;e-s+
public TestMethod() y w>T1
{ ///xx/weblogic60b2_win.exe "ju0S&
try{ R{A$hnhW6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %SD=3UK6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l/@t>%
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zv)x-48
fileFetch.start(); 8Qi@z Jq,
} x@480r
catch(Exception e){e.printStackTrace ();} ]BBL=$*
\D,c*I|p7
d`&F
} ,MdK "Qa>
ET}Dh3A
4^Ghn
public static void main(String[] args) i-_ * 5%A
{ _T[m YY
new TestMethod(); ( mKuFz7
} 7!-y72qx
} 0s8w)%4$
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