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)); S:8OQI
} v8I{XU@%
for(int i=0;i<nEndPos.length-1;i++) ibdO*E
{ '+*-s7o{
nEndPos = nStartPos[i+1]; O!Wd5Y
} Q0{z).&\(e
nEndPos[nEndPos.length-1] = nFileLength; tJ=di5&
} . -"E^f
} (shK
~"!a9GZ
@-#T5?
//启动子线程 O4No0xeWo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R<zG^m
for(int i=0;i<nStartPos.length;i++) `!G7k
{ ^ie^VY($
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M8@_Uj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *OdX u&5
nStartPos,nEndPos,i); g6sjc,`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bQaoMZB
fileSplitterFetch.start(); P|^$kK
} fj4^VXD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n~Szf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ACjf\4Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GIv){[i
nEndPos = " + nFileLength); ]v5-~E!
// fileSplitterFetch[nPos.length-1].start(); Y'Z+, CNf
HXJ9xkrr
-U>7 H`5
//等待子线程结束 (tl}q3U
//int count = 0; rwpgBl
//是否结束while循环 0]x;n+G[q
boolean breakWhile = false; >&H~nGP.
t#<KxwhcN
hN(L@0)
while(!bStop) Z,WW]Y,$
{ {@r*+~C3
write_nPos(); :w?7j_p#
Utility.sleep(500); WwW^[k (X
breakWhile = true; }`9`JmNM
C$#W{2x%6
16@);Ot
for(int i=0;i<nStartPos.length;i++) "A]Y~iQ
{ ^C9x.4I$)
if(!fileSplitterFetch.bDownOver) G5{Ot>;*%
{ oA~4p(
breakWhile = false; `W[+%b
break; XLTD;[jO
} &.*uc|{
} B50 [O!
if(breakWhile) (BERY
break; k_3j '
qa}>i&uO
CtT~0Y|
//count++; ;o$;Z4:.D
//if(count>4) MB*u-N0v
// siteStop(); 4^Ow^7N?
} HR3_@^<7
v3JPE])/
F$*3@Y
System.err.println("文件下载结束！"); j;2<-{
} n6d^>s9J
catch(Exception e){e.printStackTrace ();} *\LyNL(
} Y&,rTa
m{&w{3pQk
-NDi5i\
//获得文件长度 $o^e:Y, a
public long getFileSize() lEfBe)7+
{ i=8UBryr'e
int nFileLength = -1; -3mgza
try{ 6.Bh3p
URL url = new URL(siteInfoBean.getSSiteURL()); @8"18HEp#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a{`"68
httpConnection.setRequestProperty("User-Agent","NetFox"); s#lto0b"8
F14(;'Az
4uX(_5#j
int responseCode=httpConnection.getResponseCode(); 93I'cWN
if(responseCode>=400) 55hyV{L%
{ GOW"o"S
processErrorCode(responseCode); p`GWhI?
return -2; //-2 represent access is error ek[kq[U9
} Igjr~@#
Ky&KF0
uu>lDvR*
String sHeader; (/fT]6(
)C}KR`"
\Hs|$
for(int i=1;;i++) 5OB]x?4]
{ RqGVp?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '\L0xw4
//Utility.log(in.readLine()); Wg(bD,
sHeader=httpConnection.getHeaderFieldKey(i); pruWO'b`
if(sHeader!=null) N?+eWY
{ v[D&L_
if(sHeader.equals("Content-Length")) _>v0R'
{ 5w-JPjH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zKJ.Tj W
break; ih!~G5Xi9i
} 1#D<ZN
} A7(M,4`6
else QUPf*3Oy
break; hb! ln7
} C*O ,rm}
} vfXJYw+6_
catch(IOException e){e.printStackTrace ();} a*Jn#Mx<M
catch(Exception e){e.printStackTrace ();} [` 'd#pR
]-KV0H
@,YlmX}
Utility.log(nFileLength); fN0bIE Y
BVAr&cu
RH=$h! 5
return nFileLength; va>"#;37
} L *{QjH
b8cVnP
(H[
//保存下载信息（文件指针位置） Q)+Y}
private void write_nPos() \[k%)_
{ o4'Wr
try{ (+x]##Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); \=8=wQv
output.writeInt(nStartPos.length); #gI&lO*\gr
for(int i=0;i<nStartPos.length;i++) <Cr8V'c
{ L"^.0*X/d
// output.writeLong(nPos); ~T&% VvI
output.writeLong(fileSplitterFetch.nStartPos); (!ZV9S
output.writeLong(fileSplitterFetch.nEndPos); L1F###c
} RnSm]}?
output.close(); {Ve D@
} SJOmeN}4)
catch(IOException e){e.printStackTrace ();} *pK lA&_
catch(Exception e){e.printStackTrace ();} Oh-Fp-v87
} H%cp^G
$vqU|]J`
2R] XH 0
//读取保存的下载信息（文件指针位置） YnD#p[Wo^
private void read_nPos() 2)?
{ x?rbgsB5&
try{ &_YtY47
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L^jaBl
int nCount = input.readInt(); Dh?vU~v(6
nStartPos = new long[nCount]; W[GQ[h
nEndPos = new long[nCount]; _^b@>C>O
for(int i=0;i<nStartPos.length;i++) +]_nbWL(%
{ K{N%kk%F
nStartPos = input.readLong(); pEkOSG
nEndPos = input.readLong(); E+Im~=m$
} _lNC<7+#h
input.close(); +.wT 9kFcc
} ]DU61Z"v?b
catch(IOException e){e.printStackTrace ();} S{ey@X(
catch(Exception e){e.printStackTrace ();} :Dt\:`(r'
} RZe#|k+ 8
HrDTn&/
363cuRP
private void processErrorCode(int nErrorCode) CvP`2S\
{ O!yakU+
System.err.println("Error Code : " + nErrorCode); r/^tzH's
} 0w'|d@*wV
\.kTe<.:_
p;F2z;#
//停止文件下载 w'|&5cS
public void siteStop() +!Q!m 3/I
{ E;xMPK$
bStop = true; '1]+8E `Z
for(int i=0;i<nStartPos.length;i++) l3BD <PB2S
fileSplitterFetch.splitterStop(); 2DUr7rM
[h^f%
\U Ax(;
} 6{ C Fe|XN
} l`G(O$ct
//负责部分文件的抓取 =p5?+3"@
**FileSplitterFetch.java erXy>H[;
*/ Esb?U|F4
package NetFox; y%2%^wF
D7M0NEY
^t`f1rGR
import java.io.*; T7^ulG1'
import java.net.*; YN4"O>
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`(!W s\:
public class FileSplitterFetch extends Thread { O1|B3M[P
G&.d)NfE
jT{f<P0
String sURL; //File URL Lr wINVa
long nStartPos; //File Snippet Start Position wInY7uBd!
long nEndPos; //File Snippet End Position Is<x31R
int nThreadID; //Thread's ID >1m)%zt
boolean bDownOver = false; //Downing is over xnT3^ #-h
boolean bStop = false; //Stop identical " \`BPN
FileAccessI fileAccessI = null; //File Access interface g)X7FxS,z
HgYc@P*b
@l)\?IEF@f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (rAiDRQ[
{ )\D2\1e(c
this.sURL = sURL; uXjoGcW
this.nStartPos = nStart; i^/ eN
this.nEndPos = nEnd; L7s>su|c(
nThreadID = id; tF<^9stM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #"hJpyW 4V
} 7[4_+Q:}
^GE^Q\&D&
=d}gv6v2S
public void run() *Yj~]E0`1
{ +:fqL
while(nStartPos < nEndPos && !bStop) ESn6D@"
{ p(~Y" H
yI3Q|731)
JL?Cnk$!
try{ 45?*:)l:
URL url = new URL(sURL); ||yXp2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &$<(D0
httpConnection.setRequestProperty("User-Agent","NetFox"); gW'P`Oxw
String sProperty = "bytes="+nStartPos+"-"; KbXbT
httpConnection.setRequestProperty("RANGE",sProperty); dFdlB`L
Utility.log(sProperty); $*YC7f
u)tHOV>&
N[0 xqQ
InputStream input = httpConnection.getInputStream(); a3Z:C!|O'
//logResponseHead(httpConnection); TNyK@~#m
f#'8"ff*1
|sA4:Aq
byte[] b = new byte[1024]; UCe,2v%
int nRead; c"sj)-_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P#w}3^
{ ub[""M?
nStartPos += fileAccessI.write(b,0,nRead); <\E"clZI
//if(nThreadID == 1) +8Of-ZUx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m5X3{[a:
} l#X=]xQf
L@>^_p$
\d `dV0X
Utility.log("Thread " + nThreadID + " is over!"); #L_@s d
bDownOver = true; 7bA4P*
//nPos = fileAccessI.write (b,0,nRead); AF6d#Klog
} dNOX&$/=
catch(Exception e){e.printStackTrace ();} A Z4|&iT
} N8,EI^W8Z
} X!,#'&p&
x1.3W j
hq5NQi` %
//打印回应的头信息 '9IP;
public void logResponseHead(HttpURLConnection con) zY]Bu-S3
{ CWE Ejl
for(int i=1;;i++) 6W)xj6<@
{ *eHA: A_I
String header=con.getHeaderFieldKey(i); J ZVr&KZN
if(header!=null) U(rr vNt:t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ix*BI9E
Utility.log(header+" : "+con.getHeaderField(header)); [LJ705t
else f%bc64N(
break; DkDw>Nx<rs
} H @_eFlT t
} 4$0jz'
A Oby*c
A8\U CG
public void splitterStop() @`w'
{ B.]qrS|
bStop = true; 5u'TmLuKT
} }s`jl``PM
P3+)pOE-SI
aeG#: Ln+{
} ML=hKwCA
9 eSN+q
t7{L[C$
/* K)yCrEZ
**FileAccess.java "WF( 6z#
*//文件访问(定位，写) >{O[t2&
package NetFox; l@,);w=_P
import java.io.*; B]A 5n8<
Z_iAn TT
wm); aWP
public class FileAccessI implements Serializable{ s,eld@
>/7KL2*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2uvQf&,
RandomAccessFile oSavedFile; s(1_:
long nPos; F,'^se4&
ddUjs8VvJ
`U{o:
public FileAccessI() throws IOException {toyQ)C7
{ :)KTZ
this("",0); l(h;e&9x
} "wT~$I"
cJU!zG
p{A}p9sjx
public FileAccessI(String sName,long nPos) throws IOException }4bB7,j
{ ](B&l{V
oSavedFile = new RandomAccessFile(sName,"rw"); 8gVxiFjo
this.nPos = nPos; 5?V?
oSavedFile.seek(nPos); B(4:_j\2
} Z]mM
/E`l:&89)
l%sp[uqcg
public synchronized int write(byte[] b,int nStart,int nLen) {ED(O-W
{ 5]4<!m
int n = -1; s`8M%ZLu
try{ 6. +[ z
oSavedFile.write(b,nStart,nLen); 2+T8Y,g
n = nLen; n:5O9,umZ
} ?=;e.qK=71
catch(IOException e) es.\e.HK
{ ,cGwtt(
e.printStackTrace (); ,Az`6PW
} Rxvd+8FF
Ft%TnEp
T+AlcOP
return n; veYsctK~
} 4b3F9
W2r6jm!
.LXh]I*
} %{N$1ht^
ch5`fm
H6%!v1 u
/* R,d70w (_
**SiteInfoBean.java %=NM_5a}]
*/ ooLnJY#
package NetFox; `}k&HRn
#a7Amh\nT
}#\;np
public class SiteInfoBean { E<zT
v@$evmA
'f=)pc#&g
private String sSiteURL; //Site's URL Ckl7rpY+
private String sFilePath; //Saved File's Path zCBtD_@
private String sFileName; //Saved File's Name y~]IVl"
private int nSplitter; //Count of Splited Downloading File C>w9 {h
1K? & J2
!^>LOH>j
public SiteInfoBean() LH3N}J({
{//nSplitter的缺省值为5 }%o+1 <=
//default value of nSplitter is 5 c:?#zX
this("","","",5); %vf2||a$BS
} v GR \GFm
E&iWtwkz
wZ]BY;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z!]U&Ax`Z
{ dbMu6Bm\G
sSiteURL= sURL; BDRYip[Sa
sFilePath = sPath; }Ke}rM<
sFileName = sName; S1H47<)UF
this.nSplitter = nSpiltter; zulf%aaL
a O"nD_7
h0QYoDvbC
} ctc`^#q
Z!*8JaMT
JGSk4
public String getSSiteURL() }l]3m=)
{ pU:C=hq4
return sSiteURL; x;ICV%g/
} K+h9bI/Sf
(2O} B.6
@Q$/eL
public void setSSiteURL(String value) r3c\;Ra7
{ MuFU?3ovG*
sSiteURL = value; Ew?/@KAV\
} Z5*(W;;
}GoOE=rhY
P[#WHbn
public String getSFilePath() GqIvvnw@f
{ _pH6uuB
return sFilePath; A5.'h<
} (.quX@w"m
,rH)}C<Q+
&-8-xw#.
public void setSFilePath(String value) ~P]HG;$?n
{ -hG 9
sFilePath = value; F)E7(Un`8
} +%Bf y4F6
WB=<W#?w7%
?G>5 D`V
public String getSFileName() nIT^'
{ Kc9mI>uH
return sFileName; 4ye`;hXy
} ?(,5eg
e&H<lT
/SqFP L]
public void setSFileName(String value) @KW+?maW
{ S,`Sq8H
sFileName = value; +3o)L?:g
} F"m}mf
Z|Lh^G
hBfzU\*0H
public int getNSplitter() k9_VhR|!
{ ,3@15j
return nSplitter; [#Nx>RY
} LG&Q>pt.
:S+U}Sm[
E9Xk8w'+
public void setNSplitter(int nCount) G8(i).Q
{ soqNzdTB2
nSplitter = nCount; @8<uAu%
} E!}-qbH^
} Z'EO
qs c-e,rl
sen{f^U
/* +{Jf]"KD
**Utility.java >e$^#\D
*/ h4B#T'b
package NetFox; Ji}IV
(y+5d00
li_pM!dWU_
public class Utility { [>J~M!yu:r
{ZsWZJ!
8F\Msx
public Utility() 3R=3\;
{ |L_g/e1A3
cdtzf:#q
HyX4ob[X
} eR* ]<0=
#`#aSqGmc
//线程睡眠 dW^_tzfF7
public static void sleep(int nSecond) oIL+@}u7
{ qiKtR
try{ 5.K$ X$+7}
Thread.sleep(nSecond); G}dOx}kT
} Lq $4.l[j
catch(Exception e) 2W:?#h3
{ }b]y 0"
e.printStackTrace (); kJ<Xq
} f/[?5M[
} ;AL@<,8
tCCi|*P G
//日志 @#--dOWYR
public static void log(String sMsg) agxSb^ 8tF
{ L^al1T
System.err.println(sMsg); H'h4@S
} =3v 1]7X
UVBw;V
W$MEbf%1
public static void log(int sMsg) iQ}sp64
{ seV;f^-hR
System.err.println(sMsg); &CeF^
} ::72~'tw
} >yT@?!/Q>'
zm3MOH^a
~lalc ^
/* <,cIc]eX
**TestMethod.java "1`i]Y\'
*/ M Xt +
package NetFox; ]S2[eS
gS<{ekN
pS@VLXZP
public class TestMethod { gK#fuQ$hH
x<y[na
fJ"~XTN}T
public TestMethod() L+ETMk0
{ ///xx/weblogic60b2_win.exe gZ>orZL'
try{ w4MMo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F']%q 0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U;Y}2
SiteFileFetch fileFetch = new SiteFileFetch(bean); aj'8;E+
fileFetch.start(); D%Jc?6/I#3
} Pc; 14M
catch(Exception e){e.printStackTrace ();} ' /<b[
[qD<U%Hi
FQ~ead36C
} iN/!k.ybW}
[BR}4(7
Qbt>}?-
public static void main(String[] args) ~Ow23N
{ rKs WS~U
new TestMethod(); ?O>JtEz~lQ
} L\?g/l+k
} W;g+R-
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