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)); iJ}2"i7M
} m&Lt6_vi
for(int i=0;i<nEndPos.length-1;i++) Z.!g9fi8>
{ egfi;8]E
nEndPos = nStartPos[i+1]; Osnyd+dJY
} E]NY (1
nEndPos[nEndPos.length-1] = nFileLength; GGH;Z WSe
} #C4|@7w%
} :]'q#$!
d!o.ASL{
_*Pfp+if
//启动子线程 aC`Li^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }/20%fP
for(int i=0;i<nStartPos.length;i++) y =R aJm
{ NdZ)[f:2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }d_<\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DB#$~(o
nStartPos,nEndPos,i); g[M]i6h2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L^lS^P
fileSplitterFetch.start(); tyB)HF
} ;TtaH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XJUEwX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b7bSTFZxC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bZ/ hgqS
nEndPos = " + nFileLength); h0|[etaf
// fileSplitterFetch[nPos.length-1].start(); V{!lk]p}a
TZ'aNcGg
^]VcxKUJ
//等待子线程结束 m$?.Yig?
//int count = 0; B~?c3:6
//是否结束while循环 *|oPxQCtK
boolean breakWhile = false; F=srkw:*.
Vc|NL^
*%X.ym'
while(!bStop) T8U[xu.>
{ =^Th[B
write_nPos(); q-YL]PgV
Utility.sleep(500); Q\|18wkW
breakWhile = true; 6J\q`q(W(
|~eY%LB
L;3aZt,#O
for(int i=0;i<nStartPos.length;i++) y`rL=N#
{ $.a|ae|K
if(!fileSplitterFetch.bDownOver) F99A;M8(
{ mbyih+amCr
breakWhile = false; ;Z*'D}
break; (-\]A|
} /l^y}o %?
} usy,V"{
if(breakWhile) UeA2c_ 5
break; zj{(p Z1
I0iY+@^5
_lP4}9p
//count++; 7,h3V=^)Q
//if(count>4) Qwv '<
// siteStop(); 9\AS@SH{^T
} wlrIgn%
VG)="g[%)
uJY.5w
System.err.println("文件下载结束！"); S6GMUaR
} Wab.|\c
catch(Exception e){e.printStackTrace ();} 8b7;\C~$p
} )!eEO [\d
VD/&%O8n
Lyr2(^#:
//获得文件长度 G?<pBMy
public long getFileSize() LJWTSf"f?
{ _dr*`yXi
int nFileLength = -1; 3za`>bUN
try{ j7}lF?cJ2
URL url = new URL(siteInfoBean.getSSiteURL()); i:d`{kJ|[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Aj }]h\L
httpConnection.setRequestProperty("User-Agent","NetFox"); wu2:'y>n
N<liS3>
lUHtjr
int responseCode=httpConnection.getResponseCode(); vL$|9|W(
if(responseCode>=400) IcFK,y%1
{ f>niFPW"
processErrorCode(responseCode); A#35]V06
return -2; //-2 represent access is error I8k
} \i0-o8q@I
A*F9\mjI5
nWGR5*e:
String sHeader; Sph*1c(R
*Tp]h 0
vTd-x>n
for(int i=1;;i++) >jMH#TZaX
{ "15=ET
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]G*$W+G]
//Utility.log(in.readLine()); /lJjQ]c;>
sHeader=httpConnection.getHeaderFieldKey(i); >S'>!w
if(sHeader!=null) zh%qS~8Yv
{ 2ce'fMV
if(sHeader.equals("Content-Length")) O&V[g>x"U
{ &Mj1CvCv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BFh$.+D
break; /cfHYvnz
} Rg&19}BU
} A$@o'Q;he
else :Fw?{0
break; ZMdW2_*F
} fa{@$ppx
} 6V2j*J
catch(IOException e){e.printStackTrace ();} B\[-fq
catch(Exception e){e.printStackTrace ();} 3gc"_C\$
EwQae(PpA
:B.G)M\
Utility.log(nFileLength); fhRjYYGI
F\LsI;G
TatMf;?h&
return nFileLength; KO&:06V{
} l.oBcg[
-B9S}NPo
q- :4=vkn
//保存下载信息（文件指针位置） yW("G-Nm
private void write_nPos() d}-'<Z#G
{ xNX'~B^4d
try{ j"hASBTgp
output = new DataOutputStream(new FileOutputStream(tmpFile)); TQJF+;%
output.writeInt(nStartPos.length); e+@xsn3
for(int i=0;i<nStartPos.length;i++) QNArZ6UQ
{ :l"dYfl
// output.writeLong(nPos); v`B4(P1Z
output.writeLong(fileSplitterFetch.nStartPos); jdM=SBy7q
output.writeLong(fileSplitterFetch.nEndPos); S}cF0B1E*
} "IwM:v
output.close(); )0-o%- e
} i&&qbZt
catch(IOException e){e.printStackTrace ();} 5UOk)rOf
catch(Exception e){e.printStackTrace ();} "8HE^Po/pn
} s$GF 95^
ET-Vm >]
_-%d9@x
//读取保存的下载信息（文件指针位置） jczq`yW
private void read_nPos() sRq U]i8l
{ Pp*}R2
try{ ~@P)tl>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j=ihbR^]Tl
int nCount = input.readInt(); Q2c*.Y
nStartPos = new long[nCount]; N9]xJgTze
nEndPos = new long[nCount]; Ttv'k*$cP
for(int i=0;i<nStartPos.length;i++) O]qPmEj
{ /9_#U#vhY
nStartPos = input.readLong(); 2B` 8eb
nEndPos = input.readLong(); \r;F2C0*i
} FH*RU1Z
input.close(); ]XUSqai
} l1<?ONB.#
catch(IOException e){e.printStackTrace ();} GwQn;gkF
catch(Exception e){e.printStackTrace ();} $]*d#`Sy{%
} ~/|zlu*jpc
_tj&Psp
gs`> C(
private void processErrorCode(int nErrorCode) [5Y<7DS
{ <&U!N'CE
System.err.println("Error Code : " + nErrorCode); (WE,dY+.
} }-p,iTm
zu<3^=3
@^?XaU
//停止文件下载 YwAnqAg
public void siteStop() kon=il<@
{ Ei~f`{i
bStop = true; )N7n,_#T>
for(int i=0;i<nStartPos.length;i++) 2[up+;%Y
fileSplitterFetch.splitterStop(); 5AOfp2O
/ Z!i;@Wf
D$nK`r
} K"l0w**Og#
} @\}YAa>>"I
//负责部分文件的抓取 @ Nb%L&=P8
**FileSplitterFetch.java l h/&__
*/ M<[?g5=#
package NetFox; CgnXr/!L
%MJ;Q?KB
8#59iQl
import java.io.*; d+}kg
import java.net.*; (1){A8=?o
<xn;bp[
de YyaV
public class FileSplitterFetch extends Thread { |(ocDmd
Z;b+>2oL
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String sURL; //File URL -3hCiKq
long nStartPos; //File Snippet Start Position Q)^g3J
long nEndPos; //File Snippet End Position .mPg0
int nThreadID; //Thread's ID rkYjq4Z@
boolean bDownOver = false; //Downing is over onl>54M^
boolean bStop = false; //Stop identical f0oek{
FileAccessI fileAccessI = null; //File Access interface Kx6y" {me|
inF6M8 A1
n}J^6:1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SxMj,u%X/
{ [xdj6W
this.sURL = sURL; - DL"-%X.
this.nStartPos = nStart; +v15[^F
this.nEndPos = nEnd; Q2\
nThreadID = id; $(q8y/,R*-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G;]:$J
} _N'75
VzwPBQ -
@2' %o<lF
public void run() (ZPXdr
{ jJ++h1 K
while(nStartPos < nEndPos && !bStop) Z$;"8XUM
{ F~_;o+e;X
&KqVN]1+^
zk=\lp2
try{ e|'N(D}h*
URL url = new URL(sURL); !T'X 'Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nq;#_Rkr
httpConnection.setRequestProperty("User-Agent","NetFox"); X~RH^VYv
String sProperty = "bytes="+nStartPos+"-"; wUp)JI
httpConnection.setRequestProperty("RANGE",sProperty); P*G+eqX
Utility.log(sProperty); r4eUZ .8R
RP` `mI
?_ RYqolz
InputStream input = httpConnection.getInputStream(); X+ f9q0
//logResponseHead(httpConnection); rsF:4G"%
JBcY!dy-d
TzM=LvA
byte[] b = new byte[1024]; 2QayM?k8
int nRead; e.;M.8N#SQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #":a6%0Q
{ JJf<*j^G
nStartPos += fileAccessI.write(b,0,nRead); L11L23:
//if(nThreadID == 1) fLB1)kTS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 77We;a
} UR3$B%i
Alz~-hqQ
kx{!b3"
Utility.log("Thread " + nThreadID + " is over!"); q)iTn)Z!
bDownOver = true; X?dfcS*!n
//nPos = fileAccessI.write (b,0,nRead); |}S1o0v{(a
} t26ij`V
catch(Exception e){e.printStackTrace ();} ;f%|3-q1[
} p&3> `C
} h<3p8eB
P s#>y&
kO ![X^V
//打印回应的头信息 R&So4},B
public void logResponseHead(HttpURLConnection con) 3g'+0tEl
{ a%K}j\M
for(int i=1;;i++) )HVcG0H1
{ QIAR
String header=con.getHeaderFieldKey(i); D ,M@8h,
if(header!=null) M|%c(K#E,3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @"8R3BN
Utility.log(header+" : "+con.getHeaderField(header)); ;<-7*}Dj
else rn" pKUd
break; \P?A7vuhLs
} s4,(26y
} Tf-CEHWD
a[C&e,)}
~A >oO-0K
public void splitterStop() l$XA5#k
{ hC>wFC
bStop = true; (cs~@
} K`4GU[ul
X8CVY0<o
h4 vm{ho
} ~:2K#q5C
8:{q8xZ=k
\A(5;ZnuD
/* 3k{ @.V?]
**FileAccess.java .#!mDlY;
*//文件访问(定位，写) ,- HIFbXx@
package NetFox; (I=6Nnt'
import java.io.*; MsjnRX:c3u
#&siHHs \
9} *$n&B
public class FileAccessI implements Serializable{ ~3=2=Uf
&jm[4'$ *z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JEHK:1^
RandomAccessFile oSavedFile; qG9qN.|dC
long nPos; D#v?gPo4
oVkr3KZ
p>p'.#M
public FileAccessI() throws IOException gpAHC
{ s*JE)
this("",0); K0<yvew
} kp`0erJqw
3*WS"bt
F]5\YYXO
public FileAccessI(String sName,long nPos) throws IOException NG9vml
{ RWikJ
oSavedFile = new RandomAccessFile(sName,"rw"); Gvn: c/m;
this.nPos = nPos; v@_in(dk
oSavedFile.seek(nPos); PU+1=%'V
} Hsl{rN
hW%p#g;
z%};X$V`J
public synchronized int write(byte[] b,int nStart,int nLen) /=ylQn3 *
{ p&5S|![\
int n = -1; bi,mM,N/
try{ ^s*\Qw{Ii
oSavedFile.write(b,nStart,nLen); an KuTI
n = nLen; KjYDFrR4
} }vD;DSz:
catch(IOException e) DV,DB\P$
{ {^wdJZ~QLK
e.printStackTrace (); RbAt3k;y
} ~:Ixmqi}R
owMmCR
\`gEu{
return n; i+AUQ0Zbf6
} V6+Zh>'S
1;`Fe":;vC
~B]jV$=
} 6Ahr_{
ee<H@LeG
VN+\>j-
/* @g\;` #l
**SiteInfoBean.java Y)OBTX
*/ -<d(
package NetFox; wA",SBGX
Y^3)!>
l0#4Fma
public class SiteInfoBean { 1RA }aX
w"6aha*%7
zn^v!:[
private String sSiteURL; //Site's URL `WlH*p)z9
private String sFilePath; //Saved File's Path xp=Zd\5W$
private String sFileName; //Saved File's Name j%5a+(H,z;
private int nSplitter; //Count of Splited Downloading File K @C4*?P
g? I!OG
]|y}\7Aa
public SiteInfoBean() ZM 8U]0[X
{//nSplitter的缺省值为5 yU!GS-
//default value of nSplitter is 5 YM8rJ-
this("","","",5); ^k;mn-0
} "5(W[$f*]v
Se/ss!If
1=>2uYKR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8? F 2jv
{ L}b'+Wi@
sSiteURL= sURL; vlAy!:CV
sFilePath = sPath; GjLW`>
sFileName = sName; (QKsB3X
this.nSplitter = nSpiltter; ]f5c\\)
lfRH`u
<dS5|||
} g<a<{|
+9jivOmK
+8eVj#N
public String getSSiteURL() 1Df,a#,y"
{ ,A?{~?u.
return sSiteURL; 'rvE
} -zR.'x%
CMFC"eSe
Zg2]GJP
public void setSSiteURL(String value) :S#i9# aB
{ ] .`_, IO
sSiteURL = value; r;$r=Ufr
} h*l cEzG?A
oLd:3,p}
c{ 7<H
public String getSFilePath() !L/tLHk+
{ A^t"MYX@
return sFilePath; _=6vW^s
} kM,@[V
lqauk)(A0
n~.%p
public void setSFilePath(String value) <347 C{q
{ Vl-D<M+ih
sFilePath = value; JLml#Pu4
} $Q=$?>4U
!#C)99L"F
3eJ\aVI>pE
public String getSFileName() 50COL66:7
{ M.X}K7Z_/
return sFileName; K[n<+e;G
} )Gmb?!/^
p0
}!Xf&c{7{
public void setSFileName(String value) OW?uZ<z
{ ta@ISRK
sFileName = value; LMt0'Ml9
} xNn>+J
:J<Owh@
SCqu,
public int getNSplitter() pz.Y=V\t
{ nMLU-C!t
return nSplitter; BEFe~* ~
} -?[O"D"c
$3lt{ %
y|$vtD%c
public void setNSplitter(int nCount) bOi};/f
{ |{zHM23gD
nSplitter = nCount; pHigxeV2
} C3]\$
} dBsRm{aS
2*N&q|ED
)Uc$t${en
/* )-MA!\=<
**Utility.java %g!yccD9
*/ 0~Um^q*'3
package NetFox; M-{b
L[`R8n1C
<)r,CiS
public class Utility { 38Bnf
"bv,I-\
:;|)/
public Utility() d;;>4}XJ]
{ Bu*W1w\
#|)JD@;Q
t-3v1cv"
} yg]suU<z]
9:bh3@r/
//线程睡眠 nF|#@O`1
public static void sleep(int nSecond) #j(q/ T{x
{ tI/mE[W
try{ _lP4ez Y
Thread.sleep(nSecond); Ukk-(gjX
} UchALR^5
catch(Exception e) i{Y=!r5r
{ K,`).YK
e.printStackTrace (); IKNFYe[9e
} Jnh;;<
} =;~%L
s!8J.hD'I
//日志 W}#QKZ)MB
public static void log(String sMsg) G%V=idU*"
{ EuR!yD
System.err.println(sMsg); X ,V= od>
} GC5#1+fQ
U89]?^|bb
:F!dTD$
public static void log(int sMsg) EM>c%BH<N
{ f;@b a[
System.err.println(sMsg); u|_ITwk
} m'G?0^Ft
} N7RG5?
#+2:d?t
.N2nJ/
/* l<0[ K(
**TestMethod.java )A>U<n$h
*/ Zi[{\7a
package NetFox; ;-Y]X(z>
mh!N^[=n
g:~?U*f-
public class TestMethod { ?~]1Gd
3iwoMrp
"w:\@Jwu(
public TestMethod() |k['wqn"
{ ///xx/weblogic60b2_win.exe YoSo0fQA
try{ !Vp,YN+yN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ee$"O6*!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9TbS>o
SiteFileFetch fileFetch = new SiteFileFetch(bean); :FKYYH\
fileFetch.start(); thlpj*|
} 3isXgp8
catch(Exception e){e.printStackTrace ();} wB1-|=K1
|p=.Gg=2
$v?! 6:
} ,J`lr U0
Rsa\V6N>
:*F3
public static void main(String[] args) PpJE|[]
{ $BR=IYby
new TestMethod(); %%-U.
} ZF/J/;uI
} WIH4Aw
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