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)); a1nj}1M%
} nC>'kgRt
for(int i=0;i<nEndPos.length-1;i++) #lHA<jI
{ L1i:hgq0]
nEndPos = nStartPos[i+1]; _~_E(rTn
} `[*nUdG
nEndPos[nEndPos.length-1] = nFileLength; Yo$ xz
} fqcFfz6?x
} ]sf1+3
aHvsgp]
3.^Tm+ C
//启动子线程 '3MCb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B}YpIb]d
for(int i=0;i<nStartPos.length;i++) ozr82
{ T.{sO`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'QrvkQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZSo#vQ
nStartPos,nEndPos,i); %tRQK$]c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?\D=DIN-r
fileSplitterFetch.start(); 8A3pYW-
} HI}9"(t}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !u;r<:g!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zu@5,AH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z#!}4@_i3
nEndPos = " + nFileLength); ub* j&L=
// fileSplitterFetch[nPos.length-1].start(); X\a*q]"_
:Vyr8+]
kA1C&
//等待子线程结束 D<35FD,
//int count = 0; ue;o:>G
//是否结束while循环 m.K@g1G
boolean breakWhile = false; ^XIVWf#`H
;=?f0z<
dmkd.aP4
while(!bStop) &S8Pnb)d
{ l1h;ng6
write_nPos(); g[d.lJ=Q-N
Utility.sleep(500); V?*\ISB`}
breakWhile = true; AKbrXKx
*Ou)P9~-L
]tzO)c)w;
for(int i=0;i<nStartPos.length;i++) zL<<`u?
{ [4_JK
if(!fileSplitterFetch.bDownOver) ;F;"Uw
{ .%'$3=/oe
breakWhile = false; L =kc^dU
break; 8a;I,DK=j
} w>q:&Q
} qf7oG0
if(breakWhile) .1&~@e%=-
break; "&,Gn#'FG
N4wv'OrL]
dcGs0b
//count++; M^E\L C
//if(count>4) GT)63|
// siteStop(); wLDWD,"K
} Z?#_3h$"T
1gTW*vLM\
[= GVK
System.err.println("文件下载结束！"); 2KUm(B.I
} 9EE},D
catch(Exception e){e.printStackTrace ();} FccT@,.F
} .[E"Kb}=
&s|a\!>l
x'.OLXx>
//获得文件长度 z`^DQ8+\j
public long getFileSize() ?)ROQ1-#@
{ .)zX<~,
int nFileLength = -1; Wxi|(}
try{ 4K(AXk
URL url = new URL(siteInfoBean.getSSiteURL()); sU/R$Nbr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H</Mh*Fl2G
httpConnection.setRequestProperty("User-Agent","NetFox"); 99\;jz7
?ep'R&NV
F>0[v|LG
int responseCode=httpConnection.getResponseCode(); UA{tmIC\
if(responseCode>=400) b~1]}9TJ
{ }nQni?
processErrorCode(responseCode); (L{Kg U&{$
return -2; //-2 represent access is error &7{/ x~S{
} U8T"ABvFP
b* QRd
'>}dqp{Wr
String sHeader; [&Z3+/lR*
QEavbh^S
@-~ )M_
for(int i=1;;i++) Qe&K
{ scffWqEo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !F|mCEU
//Utility.log(in.readLine()); (&w'"-`
sHeader=httpConnection.getHeaderFieldKey(i); lR^OS*v
if(sHeader!=null) rT2gX^Mj&
{ vSt7&ec
if(sHeader.equals("Content-Length")) }|k_sx:
{ +0,{gDd+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u]B15mT?
break; Tk^J#};N
} y}fF<qih'>
} yN0!uzdW*
else AX Y.80+
break; UogkQ& B
} c\n&Z'vK
} ",b3C.
catch(IOException e){e.printStackTrace ();} \8~P3M":c
catch(Exception e){e.printStackTrace ();} jAa{;p"jU
q*Hf%I"
w/L^w50pt
Utility.log(nFileLength); U%Kv}s/(F{
D*>EWlZ
gbf-3KSp^
return nFileLength; MpV3.
} ]kN<N0;\d
?y] q\>
$Vi[195]2
//保存下载信息（文件指针位置） T,Bu5:@#
private void write_nPos() JH%^FF2
{ [|=#~(yYQ
try{ -`iXAyr)m
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y7vTseq
output.writeInt(nStartPos.length); Nn"[GB
for(int i=0;i<nStartPos.length;i++) ,~R`@5+
{ BVKr 2v
// output.writeLong(nPos); "5KJ /7q!
output.writeLong(fileSplitterFetch.nStartPos); >y2;sJ4]D%
output.writeLong(fileSplitterFetch.nEndPos); wH=L+bA>a
} COE,pb17
output.close(); arCi$:-z@
} !J5k?J&{=
catch(IOException e){e.printStackTrace ();} X#qmwcF
catch(Exception e){e.printStackTrace ();} J3]W2m2Zw
} ECO4ut.d
F/"Q0%(m
"Ih>>|r
//读取保存的下载信息（文件指针位置） V)$y
private void read_nPos() NZJ:@J=-
{ jm-J_o;}z6
try{ QFP3S(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c]#+W@$
int nCount = input.readInt(); `5[$8;
nStartPos = new long[nCount]; Q^&oXM'x/i
nEndPos = new long[nCount]; 5wy1%/;
for(int i=0;i<nStartPos.length;i++) hPCt-
{ Bf72 .gx{0
nStartPos = input.readLong(); 0{ZYYB&"~J
nEndPos = input.readLong(); BFU6?\r
} g>lJZD@
input.close(); m15MA.R>
} u|!On
catch(IOException e){e.printStackTrace ();} &C~R*
catch(Exception e){e.printStackTrace ();} N1lhlw6
} 9`"o,wGX3
I)xB I~x
e}x}Fj</(
private void processErrorCode(int nErrorCode) Xq3n7d.
{ LvWl*:z
System.err.println("Error Code : " + nErrorCode); ,0'Yj?U>
} ")/TbTVu
hX-([o
egBjr?
//停止文件下载 +GgJFBl
public void siteStop() AL%gqt]
{ *%G$[=
bStop = true; U~~Y'R\NU
for(int i=0;i<nStartPos.length;i++) 1g_(xwUp+
fileSplitterFetch.splitterStop(); 6sRe. ct<
]=s!cfu
dDuT,zP
} M18H1e@Al
} "(@W^qF}d
//负责部分文件的抓取 zW`Zmt\T2
**FileSplitterFetch.java =h?Q.vad
*/ .Z,3:3,]
package NetFox; @%4MFc0`!
jpL'y1@Ut
Q^^.@FU"x
import java.io.*; \5+?wpH
import java.net.*; b-/ztZ@u
A)5-w`1
3Y\7+975m
public class FileSplitterFetch extends Thread { Fq{Z-yVp
)V!9/d
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String sURL; //File URL V#j|_N1hm
long nStartPos; //File Snippet Start Position Gj[+{
long nEndPos; //File Snippet End Position Rw]4/
int nThreadID; //Thread's ID 4_CV.?
boolean bDownOver = false; //Downing is over /UJ@e
boolean bStop = false; //Stop identical Wvhg:vup
FileAccessI fileAccessI = null; //File Access interface }uI(D&?+h
A),nkw0X
E$$pO.\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mo+mO&B
{ y-UutI&
this.sURL = sURL; r]XXN2[jO
this.nStartPos = nStart; -29Sw
this.nEndPos = nEnd; o8 A]vaa
nThreadID = id; / 38b:,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mhp&; Q9
} jzuOs,:R
-rU~
2gn*B$a
public void run() n-h2SQl!
{ #z|\AmZ\
while(nStartPos < nEndPos && !bStop) ~[@Gj{6p0
{ ^y@RfM=A
~<M/<%o2*
sGNVZx
try{ ~|j:xM(i
URL url = new URL(sURL); 9NH"Ik*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pRsYA7Ti
httpConnection.setRequestProperty("User-Agent","NetFox"); <Sxsmf0"
String sProperty = "bytes="+nStartPos+"-"; >".,=u'
httpConnection.setRequestProperty("RANGE",sProperty); m6%csh-N1
Utility.log(sProperty); jL$&]sQ`O)
F{1;~Yg%
P]bq9!{1
InputStream input = httpConnection.getInputStream(); %-~W|Y
//logResponseHead(httpConnection); +39Vxe:Oy
-Yaw>$nJ
,hj5.;M
byte[] b = new byte[1024]; >U~B"'!xV
int nRead; ?[4!2T,Ca
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ua.7_Em
{ U @Il:\I
nStartPos += fileAccessI.write(b,0,nRead); ;4jRsirx9
//if(nThreadID == 1) 7wt2|$Qz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %21i#R`E
} =-M)2&~L~
8^fkY'x
9N9dQ}[:g
Utility.log("Thread " + nThreadID + " is over!"); MCamc
bDownOver = true; .xtjB8gc
//nPos = fileAccessI.write (b,0,nRead); !Jo3>!,j
} dzYB0vut@
catch(Exception e){e.printStackTrace ();} {~*aXu3
} sSLs%)e|:
} uN`{; Av
o0-7#2
AL.zF\?
//打印回应的头信息 @`:n+r5u
public void logResponseHead(HttpURLConnection con) C;DNL^
{ Ep%5wR
for(int i=1;;i++) 0dKI+zgr
{ kl.)A-6V
String header=con.getHeaderFieldKey(i); +):t6oX|
if(header!=null) +"Pt?k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G Q&9b_
Utility.log(header+" : "+con.getHeaderField(header)); r`]&{0}23
else K 7)1wiEj
break; 0G/VbS
} Jtj_Rl !
} W_EM k
nZ>bOP+,
GyV3]Qqj
public void splitterStop() !F0MLvdX7^
{ wj>mk
bStop = true; aa<9%j
} W4yNET%l,
|]a=He;
@Taj++ua
} &z;;Bx0s
Wxl^f?I`:
OE(H:^ZR
/* !FweXFl
**FileAccess.java %H:uE*WZ
*//文件访问(定位，写) qvz2u]IOw
package NetFox; Wjt1NfS&
import java.io.*; daT[2M
kBY54pl
ScrEtN
public class FileAccessI implements Serializable{ uX{n#i,~L
N> RabD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MnvFmYgxA
RandomAccessFile oSavedFile; ZF :e6em
long nPos; mj0{Nd
./@!k[
QRnkj]b
public FileAccessI() throws IOException ~je#gVoUR
{ JGPLVw
this("",0); >=hOjV;
} UhCE.# U
eR r.j
0$3\DS<E
public FileAccessI(String sName,long nPos) throws IOException QRj><TKi
{ ReOp,A/y
oSavedFile = new RandomAccessFile(sName,"rw"); 2=X2M
this.nPos = nPos; -ea>}S
oSavedFile.seek(nPos); 8P r H"pI
} @NGK2J
>W"gr]R<
(#* 7LdZ
public synchronized int write(byte[] b,int nStart,int nLen) d%?+q0j
{ W=M`Bkw{
int n = -1; <}b`2/wP
try{ %sb)U~gP
oSavedFile.write(b,nStart,nLen); ZdHfZ3)dB
n = nLen; _[-+%RP
} IM&2SSmYNH
catch(IOException e) 3vPb}
{ bs!N~,6h
e.printStackTrace (); 5uMh#dm^
} <v;;:RB6c
I*R[8|
_aVrQ@9
return n; OaU-4 ~n;
} mxtLcG4G
Z%~j)
V6"<lK8"
} #|fa/kb~
vCT5do"C&
fk)ts,p?
/* tS,nO:+x
**SiteInfoBean.java |du@iA]dP
*/ *,hS-
package NetFox; LtKiJ.j?A
t3K7W2bz
D.o|pTZ
public class SiteInfoBean { }fnp}L
kf+]bV
MZf$8R
private String sSiteURL; //Site's URL ]Mi ~vG q
private String sFilePath; //Saved File's Path Pk[:+. f(
private String sFileName; //Saved File's Name 5Jq~EB{"
private int nSplitter; //Count of Splited Downloading File i rMZLc6
w#eD5y~'oo
Y3r m')c
public SiteInfoBean() IlsXj`!e
{//nSplitter的缺省值为5 /2-S/,a
//default value of nSplitter is 5 v!?bEM3D
this("","","",5); H];|<G
} ]kq{9b';
a'f"Zdh%w
. $uvQpyh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o^;$-O!/
{ 6H67$?jMyJ
sSiteURL= sURL; <jF]SN
sFilePath = sPath; emOd<C1A
sFileName = sName; x/Se /C
this.nSplitter = nSpiltter; [Hz_x(t26
ZB GLwe
Xn-GSW3{
} \y^Od7F
F+Rtoq|
8*3o9$Pj
public String getSSiteURL() pDb5t>
{ 'gk.J
return sSiteURL; B PTQm4TN
} W-q2|NK
G$pTTT6#
q}>1Rr|U`
public void setSSiteURL(String value) ?D-1xnxep
{ duB{1
sSiteURL = value; BJ!b LQ
} ?|'+5$
B1T:c4:N
84^'^nd
public String getSFilePath() cjt<&b*
{ \#.,@g
return sFilePath; 7l> |G,[c
} D].!u{##
T:q_1W?h]
~4h<nc
public void setSFilePath(String value) 6s\niro2
{ S[!K
sFilePath = value; \$YKw0K
} 6M9t<DQV
lP& 7U
:8aa#bA
public String getSFileName() ^%|,G:r
{ OQMkpX-dH
return sFileName; I&~kwOP
} \Zz"%i
0 3fCn"
exw~SvT3
public void setSFileName(String value) ,gGIkl&
{ t-Rfy`I3
sFileName = value; D7|[:``
} (n+2z"/
OJiW@Z_\
qp_lMz
public int getNSplitter() .gTla
{ Hs/ aU_
return nSplitter; lo*OmAF
} \7PPFKS
Q\Dx/?g!vx
r!SMF]?SJ
public void setNSplitter(int nCount) ^Gt&c_gH
{ u~n*P``{
nSplitter = nCount; P'.MwS
} .zQ:u{FT
} )9F-h8 &"
f =@'F=
>)*'w!
/* )QYg[<e6
**Utility.java 2g5i3C.q$
*/ HA&7 ybl
package NetFox; Jb~$Vrdy
H'k$<S
Y,Dd}an
public class Utility { %@ UH,Ew
ITJ{]7N
BrF/-F
public Utility() nMXk1`|/)x
{ A>WMPe:sSS
it]im
}5c%v1
} i!g}PbC[
r09gB#K4
//线程睡眠 u3 k%
public static void sleep(int nSecond) <knf^D<"
{ ;6S,|rC]
try{ S:)Aj6>6
Thread.sleep(nSecond); ]D?//
} ta"uxL\gge
catch(Exception e) G165grGFd
{ ~hK7(K
e.printStackTrace (); F.5'5%
} wZ6D\I
} rk$&sDc/3
9A_{*E(wd
//日志 S3#NGBZ/
public static void log(String sMsg) B1<:nl
{ TNe,'S,%
System.err.println(sMsg); Z9X<W`
} MzjV>.
D![42H+-Qd
E;!pK9wL|
public static void log(int sMsg) $A~UA
{ zVN/|[KP4
System.err.println(sMsg); GL;@heP
} y/=:F=H@w
} :})(@.H
58xaVOhb
Ku;|Dz/=o
/* \f| Hk*@
**TestMethod.java DV+M;rs
*/ ?bFP'.
package NetFox; k1tJ$}
X&C&DTB
j("$qpv
public class TestMethod { \H(r }D$u<
_vOV(#q2a
,n\"zYf]^
public TestMethod() _Z~cJIEU
{ ///xx/weblogic60b2_win.exe ;R[ xo!
try{ 1 &G0;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |OW/-&)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y8} fj=
SiteFileFetch fileFetch = new SiteFileFetch(bean); WgHl. :R
fileFetch.start(); m$N`Xj
} wq yw#)S
catch(Exception e){e.printStackTrace ();} @ig'CF%(
x_za R}WI
6cR}Mm9Hx3
} xPBSJhla
(al.7VA;9
$+(Df|)
public static void main(String[] args) Mdk(FG(
{ <Q57}[$*)
new TestMethod(); N:R6 b5 =}
} ++O L&n
} OJ#ehw<
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