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)); Mo4#UV
} <4caG2~q
for(int i=0;i<nEndPos.length-1;i++) m~upTQz
{ 8|\0\Wd;vu
nEndPos = nStartPos[i+1]; |sa{!tKJ
} NS^(5g
nEndPos[nEndPos.length-1] = nFileLength; iti~RV,
} QH_0U`3
} pI__<
l?_h(Cq<
i{['18Q$F3
//启动子线程 OK=lp4X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z0XH`H|~
for(int i=0;i<nStartPos.length;i++) pP1|/f5n`
{ TB=KTj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T?p'R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gnAM}
nStartPos,nEndPos,i); sn|q EH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m 6Xex.d
fileSplitterFetch.start(); !^o(?1
} bp'qrcFuiL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (WW*yv.J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |7ga9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", aY/msplC
nEndPos = " + nFileLength); {i:5XL
// fileSplitterFetch[nPos.length-1].start(); &}TfJ=gj
Q}a, f75
\ 2cI=Qf
//等待子线程结束 RoL5uha,l
//int count = 0; M"q]jeaM
//是否结束while循环 Rnl 4
boolean breakWhile = false; ^LA.Y)4C2%
8{mQmG4
h)O<bI8
while(!bStop) 6SYQRK
{ Iyo ey
write_nPos(); @B<B#
Utility.sleep(500); DXbzl +R
breakWhile = true; eSV_.uvsb
*b{C`[ =V
q>$[<TsE&}
for(int i=0;i<nStartPos.length;i++) bzz{ p1e
{ ^8_`IT
if(!fileSplitterFetch.bDownOver) Fx^e%":@ip
{ uO4kCK<7C
breakWhile = false; x~7_`=}rO
break; >DHpD?Pm!
} IEi E6z]L(
} Z*/*P4\
if(breakWhile) amPC C
break; Hk65c0
6 (:^>@
X>i`z
//count++; ZBDEE+8e
//if(count>4) (<u3<40[YN
// siteStop(); vV2px
} /xK5%cE>B
O@.afk"{
_}_lrg}U
System.err.println("文件下载结束！"); &9Vm3X
} P#_8$#G3
catch(Exception e){e.printStackTrace ();} njz:7]>e
} Tk9/1C{8
M4;A4V=W
z0@)@4z!
//获得文件长度 In-W,
public long getFileSize() 9fWr{fx
{ /ae]v+
int nFileLength = -1; D,aJ`PK~
try{ Z;/"-.i
URL url = new URL(siteInfoBean.getSSiteURL()); C:$12{I?*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QK+s}ny
httpConnection.setRequestProperty("User-Agent","NetFox"); 'O#,;n
eRlJ
&"V%n
int responseCode=httpConnection.getResponseCode(); &FQ]`g3_@
if(responseCode>=400) ?K<m.+4b*y
{ rUunf'w`e1
processErrorCode(responseCode); l:!4^>SC
return -2; //-2 represent access is error bL=32YS
} yPKDn.1
vt;<+"eps
a'/yN{?p
String sHeader; 69Y>iPRU
dHU#Y,v
'o2V}L'nG
for(int i=1;;i++) YF{KSGq
{ P7IxN)b7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4<`x*8` ,
//Utility.log(in.readLine()); # ;,b4O7@
sHeader=httpConnection.getHeaderFieldKey(i); _IAvFJI
if(sHeader!=null) R/H?/
{ `r; .
if(sHeader.equals("Content-Length")) m6qmZ2<
{ +C~,q{u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8T5s6EmIOW
break; {FR#je
} >$gWeFu
} dAOmqu,6
else bSW!2#~
break; I,{9vew
} TQx''$j\
} E'p5
catch(IOException e){e.printStackTrace ();} %@<}z|.4
catch(Exception e){e.printStackTrace ();} 9R XT
/rd6p{F
05".;(
Utility.log(nFileLength); (7nWv43
7y",%WYSD
Qtmsk:qm
return nFileLength; MSPzOJQPy
} 1=DUFl.
>w:px$g4
PI7M3\z
//保存下载信息（文件指针位置） )J/,-p
private void write_nPos() nq#k}Qx:
{ r4}:t$
try{ f-5vE9G3y7
output = new DataOutputStream(new FileOutputStream(tmpFile)); .tB[8Y=J
output.writeInt(nStartPos.length); D7%`hU
for(int i=0;i<nStartPos.length;i++) w.qpV]9>
{ aHKv*-z-
// output.writeLong(nPos); B\2<r5|QG
output.writeLong(fileSplitterFetch.nStartPos); $'}:nwq6x
output.writeLong(fileSplitterFetch.nEndPos); *iB_$7n`
} V@jR8zv|_
output.close(); Sqw.p#
} 4|fI9.
catch(IOException e){e.printStackTrace ();} Rv=(D^F,
catch(Exception e){e.printStackTrace ();} [guJd";
} ~4th;#'
#UH|,>W6
Q!Rknj 2
//读取保存的下载信息（文件指针位置） v&}mbt-
private void read_nPos() 9N>Dp N
{ [((P,v*
try{ [`P+{ R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &Y"u*)bm
int nCount = input.readInt(); XW6>;:4k
nStartPos = new long[nCount]; D_,}lsrb
nEndPos = new long[nCount]; -#v1b>ScY
for(int i=0;i<nStartPos.length;i++) `gq@LP"o
{ 3_(fisvx
nStartPos = input.readLong(); qw[)$icP
nEndPos = input.readLong(); [Q,E( s
} uX@RdkC
input.close(); #$(F&>pj
} ^{8r(1,
catch(IOException e){e.printStackTrace ();} _yTGv-
catch(Exception e){e.printStackTrace ();} ' }rUbJo
} b_*Y5"(*
+Io^U
*axOen
private void processErrorCode(int nErrorCode) >\hu1C|W
{ //VgPl
System.err.println("Error Code : " + nErrorCode); +*[lp@zU{
} lmb5Z-xB
qp>O#tj[
ev>gh0
//停止文件下载 1R)4[oYN\<
public void siteStop() sW 7R&t!G
{ G S-@drZp_
bStop = true; 79<{cexP
for(int i=0;i<nStartPos.length;i++) L.bR\fE
fileSplitterFetch.splitterStop(); oDul ?%
xg)cA C\=
)sG`sET]`f
} ppIMaP
} I9Af\ k|^
//负责部分文件的抓取 O3#4B!J$E
**FileSplitterFetch.java [ajF
*/ +_uT1PsBY
package NetFox; djV^A
A?8f 6
_wp6rb:8!
import java.io.*; %^xY7!{
import java.net.*; F*hOa|7/
ZRO
7Zp'}Om<I
public class FileSplitterFetch extends Thread { \I; lgz2
92+LY]jS
Cul^b_UmP#
String sURL; //File URL ZLe@O~f;%
long nStartPos; //File Snippet Start Position wwVK15t
long nEndPos; //File Snippet End Position ',nGH|K.
int nThreadID; //Thread's ID #/t^?$8\\
boolean bDownOver = false; //Downing is over Pq`]^^=be'
boolean bStop = false; //Stop identical s=Pwkte
FileAccessI fileAccessI = null; //File Access interface $-Q,@Bztq
dK,j|
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p=jD "lq
{ wI\v5&X-B
this.sURL = sURL; bb[.Kvq5
this.nStartPos = nStart; E$m3Gg)s>N
this.nEndPos = nEnd; DLe?@R5
nThreadID = id; jx a?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cP63q|[[
} j?4k{?x
aH'Sz'|E
E[HXbj"
public void run() :9q=o|T6D
{ #4_'%~-e
while(nStartPos < nEndPos && !bStop) Ua]shSjyI
{ T(K~be
j K?GB
Z8+{ -
try{ `s(T(l
URL url = new URL(sURL); ZWaHG_ U)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %qL0=ad
httpConnection.setRequestProperty("User-Agent","NetFox"); .]g>.
String sProperty = "bytes="+nStartPos+"-"; qQ[&FjTO`
httpConnection.setRequestProperty("RANGE",sProperty); (1gfb*L
Utility.log(sProperty); O]RP?'vO
vttmSdY
x9R_KLN:;
InputStream input = httpConnection.getInputStream(); F,EcqM'f
//logResponseHead(httpConnection); B!H46w~
54s+4R FL
sG*1?
byte[] b = new byte[1024]; 5$0@f`sj
int nRead; |=2E?&%?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MHmaut#
{ vs;T}'O
nStartPos += fileAccessI.write(b,0,nRead); |H 0+.f;
//if(nThreadID == 1) Fp..Sjh 6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q:@$$}FjL
} !q;EC`i#
%YLdie6c
J4!Om&\@
Utility.log("Thread " + nThreadID + " is over!"); iZ2|/hnw
bDownOver = true; &S9Sl
//nPos = fileAccessI.write (b,0,nRead); =FQ]eb*
} ,2S w6u
catch(Exception e){e.printStackTrace ();} >Du5B&41
} C4e3Itc9X
} $EHAHNL?Lx
d-nqV5
W*iPseXq
//打印回应的头信息 x0B|CO
public void logResponseHead(HttpURLConnection con) ;o }pRC
{ @SeE,<
for(int i=1;;i++) j4Ppn
{ 6O8'T`F[
String header=con.getHeaderFieldKey(i); A$.woE@
if(header!=null) [xq"[*Evv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /H&:
Utility.log(header+" : "+con.getHeaderField(header)); )MqF~[k<-
else B]~#+rMK
break; `G> 6
} cN_e0;*Ua
} \xJTsdd
/Ps}IW
pfsRV]
public void splitterStop() fl>*>)6pm
{ @/i{By^C
bStop = true; cLR02
} 3OTq
FC+K2Yf1=0
~Q%C>
} (cJb/|?3
GY 4?}T^s
MB;<F
/* m~ :W$x1+
**FileAccess.java ZOvMA]Rf
*//文件访问(定位，写) FM:ax{
package NetFox; 94Mh/A9k
import java.io.*; _UKH1qUd4
QWG?^T fi
f@Mm{3&.
public class FileAccessI implements Serializable{ i2`i5&*
"mr;|$Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i3g;B?54
RandomAccessFile oSavedFile; 9NLO{kN
long nPos; {FyGh */
nsk`nck
Tx"}]AyB6
public FileAccessI() throws IOException <Okk;rj2
{ +Z[(s!
this("",0); /~*U'.V
} aY7kl
P[-2^1P"
5\/h3i"I
public FileAccessI(String sName,long nPos) throws IOException rSDS9Vf(
{ c-8Pc]+g
oSavedFile = new RandomAccessFile(sName,"rw"); !m(5N4:vV
this.nPos = nPos; z17
oSavedFile.seek(nPos); TZL)jfhj
} e!wBNcG2
Q?rb(u(
x"0*U9f
public synchronized int write(byte[] b,int nStart,int nLen) wQiRj.
{ Z[:fqvXQ
int n = -1; s8iJl+Jm
try{ L>Bf}^
oSavedFile.write(b,nStart,nLen); r2H_)Oi
n = nLen; ~$} `R=
} :{<( )gfk
catch(IOException e) W_(
{ -~T?xs0_
e.printStackTrace (); _q`$W9M+k
} Av[L,4A
Rg~ ~[6G>
*l:5FTp
return n; %mr
} sxcpWSGA^
oZ;u>MeZ
?z>ZsD
} 1!<k-vt
7Wub@Mp
6( TG/J
/* <*u[<
**SiteInfoBean.java &scHyt
*/ Qk?;nF
package NetFox; #7K&x.w$
!Tuc#yFw
gf2<dEff
public class SiteInfoBean { ZVu&q{s,
.nX+!EXeS
PEZ~og:w
private String sSiteURL; //Site's URL [|<2BQX
private String sFilePath; //Saved File's Path RGy4p)z*+
private String sFileName; //Saved File's Name Ftu~nh}
private int nSplitter; //Count of Splited Downloading File g,/gApa
|KFRC)g
>en,MT|
public SiteInfoBean() fnV^&`BB
{//nSplitter的缺省值为5 xe5|pBT
//default value of nSplitter is 5 !X721lNP
this("","","",5); .z7%74p
} j<w";I&Diz
Xi3:Ok6FZ
Ht#5;c2/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xFcJyjo^z
{ i_8q!CL@{
sSiteURL= sURL; A9^t$Ii
sFilePath = sPath; bQc-ryC+.
sFileName = sName; yZFm<_9>
this.nSplitter = nSpiltter; [U[saR\
dX|(n.}
\5.36Se
} 3D>syf
apQ` l^
7A@GNA
public String getSSiteURL() ]&%_Fpx
{ C8i6ESmU
return sSiteURL; 1B+uv0lA
} q]+'{Ci@
Ru8k2d$B
nE+OBdl
public void setSSiteURL(String value) tM3eB= .*
{ Stqlp<xy
sSiteURL = value; "i/ l'
} Oi#F
xu[6h?u(h8
=jZ}@L/+
public String getSFilePath() )Cl!,m)~
{ NU>={9!
return sFilePath; u'}SaX]0
} _ S%3?Q
`?)ivy>\:
kd^CZ;O
public void setSFilePath(String value) IfF@$eO
{ wc##'u
sFilePath = value; `!{m#BBT}
} K~Lh'6
R5=2EwrGP
A?I/[zkc
public String getSFileName() ,YzrqVY
{ )`5kfj
return sFileName; w yi n
} _(=[d
w_o|k&~,
M_@%*y\o
public void setSFileName(String value) --*Jv"/0
{ t,|`#6Ft
sFileName = value; _kR);\V.8
} ]A)`I
kGbtZ} W
d%tF~|#A%
public int getNSplitter() K^0cL%dB
{ c zTr_>
return nSplitter; wWV`k
} oGz-lO{lt
()L[l@m
[:Kl0m7
public void setNSplitter(int nCount) Q; DN*
{ (dZu&
nSplitter = nCount; %\OG#36
} }c/p+Wo
} Uz(Sv:G
wxw3t@%mNm
hxcRFqX"
/* 9 -7.4!]I
**Utility.java ~RdJP'YF-
*/ -olD!zKS
package NetFox; a(>oQG8F
-90qG"@
I75>$"$<
public class Utility { *N5cC#5`=
!Yuu~|
7q_B`$ata
public Utility() @&!`.Y oy
{ Th&-n%r9K
8%-+@\=
3q7Z?1'o
} CjW`cHd
LU$aCw5 B;
//线程睡眠 v5J% p4
public static void sleep(int nSecond) Jo%5NXts4
{ ]:Y@pZ
try{ (.6~t<DRv
Thread.sleep(nSecond); a "*DJ&
} 8}9B*m
catch(Exception e) &fH;A X.
{ tNsiokOm
e.printStackTrace (); 'F3cvpc`
} D vG9(Eh
} C:Tjue{G2
)*!"6d)^
//日志 J=QuZwt
public static void log(String sMsg) 2M`]nAk2a
{ $$my,:nH
System.err.println(sMsg); <_X`D4g]XO
} !V|%n(O"
v X=zqV
6:Eu[PE~w
public static void log(int sMsg) 34k}7k~n
{ g5THkxp
System.err.println(sMsg); cBxBIC
} /]pBcb|<
} .Pz( 0Y
x\/N09
px`o.%`'
/* 9ure:Dko(Y
**TestMethod.java j,@N0~D5
*/ []opPQ 1
package NetFox; k[6%+
i-6,r[<
P<&-8QA
public class TestMethod { i7@qfe$fR
cL/6p0S
hEG-,
public TestMethod() ?9jl8r>
{ ///xx/weblogic60b2_win.exe `$V7AqX(
try{ V4c$V]7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cRt[{HE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )"Ef* /+
SiteFileFetch fileFetch = new SiteFileFetch(bean); kJ^)7_3
fileFetch.start(); mM*jdm(!
} EP!zcp2' C
catch(Exception e){e.printStackTrace ();} cM9z b6m
W*D]?hXU;
0MV^-M
} 3I|&}+Z6
4}mp~AXy;z
CHeU`!:
public static void main(String[] args) /$]#L%
{ a(|YLN
new TestMethod(); U%E6"Hg
} Dm=d
} SkGh@\
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