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)); Bq# l8u
} 8 FJ>W.
for(int i=0;i<nEndPos.length-1;i++) m0$~O5|4
{ q>^x,:L
nEndPos = nStartPos[i+1]; RY\[[eG
} ! ,v!7I
nEndPos[nEndPos.length-1] = nFileLength; zmEg4v'I
} FKVf_Ncf%
} A2xfNY<
1#OM~v6B
7hLdCSX
//启动子线程 c c^I9g~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U5f<4I
for(int i=0;i<nStartPos.length;i++) :}[RDF?
{ \5ZDP3I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HZ8k%X}1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /^jV-Z`
nStartPos,nEndPos,i); w<54mGMOLr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \y\@=j
fileSplitterFetch.start(); 6.>l
} F%s'R 0l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rf[w&~R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NMCMY<o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _go1gf7
nEndPos = " + nFileLength); HT@/0MF{J
// fileSplitterFetch[nPos.length-1].start(); 0)Wrfa
/CT g3Q"KQ
m~xO;_m
//等待子线程结束 6t0-u~
//int count = 0; *(pmFEc
//是否结束while循环 *^WY+DV
boolean breakWhile = false; 017(I:V?(:
7Ns1b(kU
_1sjsGp>
while(!bStop) B+w< 0No
{ b+DBz}L4
write_nPos(); `N,q~@gL
Utility.sleep(500); 1TIP23:
breakWhile = true; >qT4'1S*g
Fb:Z.
^7zXi xp
for(int i=0;i<nStartPos.length;i++) ,vE)/{:d
{ *|F ;An.N^
if(!fileSplitterFetch.bDownOver) {;0+N -U
{ ? 016
breakWhile = false; }.$5'VGO
break; s<;kTReA
} B[8`l} t
} pndAXO:v
if(breakWhile) Z8yt8O
break; A@I( &Z
C2/B1ba
x+V@f~2F
//count++; PE7D)!d T
//if(count>4) fZ6"DJZ
// siteStop(); Sph:OX8
} sERm+x<
c&rS7%
3%'Y):
System.err.println("文件下载结束！"); (tLAJ_v!.K
} t R(Nko
catch(Exception e){e.printStackTrace ();} @9X+ BdQU
} 'U8% !
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F4xXJ"vc
//获得文件长度 ^o@N.+`&<
public long getFileSize() u#&ZD|
{ =,4iMENm!
int nFileLength = -1; X":T>)J-
try{ I6B`G Im5
URL url = new URL(siteInfoBean.getSSiteURL()); 8U$(9X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]g0h7q)79
httpConnection.setRequestProperty("User-Agent","NetFox"); (aQNe{D#
},W<1*|
<RFT W}f!
int responseCode=httpConnection.getResponseCode(); zZ11J0UI
if(responseCode>=400) ^zs]cFN#%
{ u}:p@j}Zv
processErrorCode(responseCode); %0<-5&GE
return -2; //-2 represent access is error "dN4EA&QJ
} ys#V_ysb
dhAkD-Lh
-{tB&V~+v
String sHeader; rbEUq.Yk]~
>Y\$9W=t
1m5=Nu
for(int i=1;;i++) |'R^\M Q
{ 6|O2i j-J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MMYV8;c
//Utility.log(in.readLine()); Oz:J8l%
sHeader=httpConnection.getHeaderFieldKey(i); #,4CeD|(D,
if(sHeader!=null) )8rN
{ A/%+AH(
if(sHeader.equals("Content-Length")) )PNeJf|@
{ `BA,_N|6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '. '}
break; 5,,b>Z<
} F^mMyK
} *t-Wol
else 2 u{"R
break; UDUj
} 4-wCk=I
} {}W9m)I
catch(IOException e){e.printStackTrace ();} U~)i&":sN
catch(Exception e){e.printStackTrace ();} \~O}V~wE
AdWLab;
@2>j4Sc
Utility.log(nFileLength); P`$"B0B)
yL#bZ9W }
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return nFileLength; ~$PQ8[=
} s:fy *6=[Z
MBO3y&\S4
'0juZ~>}
//保存下载信息（文件指针位置） TO|&}sDh
private void write_nPos() LG/6_t}
{ GF3"$?Cw
try{ vp>,}nx4
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1lJY=`8qa
output.writeInt(nStartPos.length); M2.Pf s
for(int i=0;i<nStartPos.length;i++) 3,QsB<9Is
{ 9\aR{e,1
// output.writeLong(nPos); QS*!3?%
output.writeLong(fileSplitterFetch.nStartPos); O6[,K1,
output.writeLong(fileSplitterFetch.nEndPos); xMb)4cw}
} 64hl0'67y
output.close(); DAPbFY9
} %e71BZo~^s
catch(IOException e){e.printStackTrace ();} jYv`kt
catch(Exception e){e.printStackTrace ();} 7a4b,-93
} z TM1 e
b/I_iJ8t
*s"dCc
//读取保存的下载信息（文件指针位置） Pz/bne;=
private void read_nPos() X;hV+|Bo
{ %O!~!'
try{ <![]=~z$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k70o=}
int nCount = input.readInt(); Jp0*Y-*Y
nStartPos = new long[nCount]; giDe
nEndPos = new long[nCount]; n&`=.[+A
for(int i=0;i<nStartPos.length;i++) SG)hrd
{ v`Iw:?)%
nStartPos = input.readLong(); wTL&m+xr
nEndPos = input.readLong(); ZE!dg^-L
} )Ycjx~
input.close(); Wd R~
} =xa:>Vh#
catch(IOException e){e.printStackTrace ();} rTgCmr'&
catch(Exception e){e.printStackTrace ();} ^D{!!)O
} 3miEF0x[
TxN'[G
lhyWlO
private void processErrorCode(int nErrorCode) ?0U.1N
{ ?0{8fGM4
System.err.println("Error Code : " + nErrorCode); NJVAvq2E.
} RwG@C|sG
h{R>L s
[|XMR=\>
//停止文件下载 ?_!} lg
public void siteStop() ;Tn$c70
{ +;H-0Q5
bStop = true; jmDQKqEc|l
for(int i=0;i<nStartPos.length;i++) aWG7k#nE
fileSplitterFetch.splitterStop(); Ed(6%kd
Y\Z.E;
rhLm2q
} uh][qMyLM
} ^RS?y8
//负责部分文件的抓取 g.&n X/
**FileSplitterFetch.java %LH~Im=
*/ Spnshv8
package NetFox; Nan@SuKY
%`kO\q_
7V^\fh5~
import java.io.*; E&}@P0^
import java.net.*; VSW:h
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'T8(md299
public class FileSplitterFetch extends Thread { D9cpw0{nc
.+;;-]})
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String sURL; //File URL gCVgL]jj(
long nStartPos; //File Snippet Start Position y)s+/Teb
long nEndPos; //File Snippet End Position *~t&Ux#hj
int nThreadID; //Thread's ID * [\H)Lz
boolean bDownOver = false; //Downing is over 0""t`y&
boolean bStop = false; //Stop identical i#uc
FileAccessI fileAccessI = null; //File Access interface ?!h jI;_&
) r8yt}
&vDK6w,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?"d25LyN
{ WSt&?+Y
this.sURL = sURL; x*Lm{c5+
this.nStartPos = nStart; u~WE}VC
this.nEndPos = nEnd; Ik4FVL8~
nThreadID = id; hzT,0<nw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1Q&\y)@bT
} ku@sQn
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oj|\NlR
public void run() .4jU G=
{ z qM:'x*
while(nStartPos < nEndPos && !bStop) XZ8#8Di8
{ q;W(;B
w:|BQ,
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try{ X9J&OQ[W
URL url = new URL(sURL); cv .R`)l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6AM-^S@
httpConnection.setRequestProperty("User-Agent","NetFox"); =B0#z]qu
String sProperty = "bytes="+nStartPos+"-"; Gu3# y"a>
httpConnection.setRequestProperty("RANGE",sProperty); &YSjwRr
Utility.log(sProperty); (?G?9M#7_
-3z$~ {
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InputStream input = httpConnection.getInputStream(); R-L*N$@!
//logResponseHead(httpConnection); CJ@G8>
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byte[] b = new byte[1024]; -<Wv7FNpD
int nRead; MJ=(rp=YU9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]M:=\h,t>
{ jD`p;#~8
nStartPos += fileAccessI.write(b,0,nRead); kp{q5J6/
//if(nThreadID == 1) ;tBc&LJ?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lrr1) h
} $Ur-Q d
*!~jHy8F
O&]P u5
Utility.log("Thread " + nThreadID + " is over!"); ,?'":T1[
bDownOver = true; cZ<@1I5QK
//nPos = fileAccessI.write (b,0,nRead); D2060ze
} 9r5<A!1#L
catch(Exception e){e.printStackTrace ();} ]*M VVzF
} f _ O
} X\Y:9^5
zqDG#}3f^
,KfBG<3
//打印回应的头信息 {JJq/[j
public void logResponseHead(HttpURLConnection con) -Um|:[*I
{ ^lt;K{
for(int i=1;;i++) Po ,zTz
{ X;~3 U 9
String header=con.getHeaderFieldKey(i); y<Z-f.
if(header!=null) rJ@yOed["b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q1|! oQ
Utility.log(header+" : "+con.getHeaderField(header)); i*T>,z
else `8.Oc;*zu
break; 2[O\"a%
} &s+F+8"P+
} Po~u-5
RPXkf71iM
q h+c}"4m
public void splitterStop() gz,x6mnQ
{ ~> xVhd
bStop = true; =:4vRq [
} jkN-(v(T
+Kw&XRAd
nB8JdM2h{
} -F]0Py8(
FL,av>mV
l'K3)yQEJ
/* YFGQPg
**FileAccess.java SWrt4G
*//文件访问(定位，写) ]]InD N
package NetFox; 7AOjlC9R}
import java.io.*; 2I!L+j_
K F:W:8
^2|G0d@.:
public class FileAccessI implements Serializable{ 0cpI2
ranlbxp2l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &3o[^_Ti
RandomAccessFile oSavedFile; |x Nd^
long nPos; 3 zF"GT
'&|]tu:q
N9[2k.oBH
public FileAccessI() throws IOException "I7 Sed7
{ OLl?1
this("",0); Dd=iYMm7
} @S-p[u
cP]5Qz
SU {U+
public FileAccessI(String sName,long nPos) throws IOException B(omD3jzN
{ ;'|Mt)\
oSavedFile = new RandomAccessFile(sName,"rw"); uia[>&2
this.nPos = nPos; 3hPj;-u
oSavedFile.seek(nPos); x'uxSeH$
} M.[A%_|P
r N.<S[
G T3wJQ5N
public synchronized int write(byte[] b,int nStart,int nLen) opQdym
{ u`Sg'ro
int n = -1; z.xOT;t
try{ UImd*;2TE
oSavedFile.write(b,nStart,nLen); HgY#O r(
n = nLen; h/AL`$
} 1Ar6hA
catch(IOException e) knPo"GQW
{ :We}l;.jQ
e.printStackTrace (); [^J2<\<0
} c^$+=-G{fd
(I) e-1
PN +<C7/
return n; fV\ eksBF
} L, k\`9bQ
gLH#UwfJ
On^jHqLaE
} )]^xy&:|
_BA2^C':c{
pFUW7jE
/* mHnHB.OL
**SiteInfoBean.java dWCUZ,6}
*/ )(Z)yz
package NetFox; 6z(eW]p
XQH wu
#fb <\!iza
public class SiteInfoBean { 9qqzCMrI0e
Y?^1=9?6
'%D$|)
private String sSiteURL; //Site's URL /{j")
private String sFilePath; //Saved File's Path oI!L2
private String sFileName; //Saved File's Name SvE|"
private int nSplitter; //Count of Splited Downloading File <0,szw
pO;BX5(x
AIx,c1G]K
public SiteInfoBean() g#=~A&4q
{//nSplitter的缺省值为5 f\Fk+)e@
//default value of nSplitter is 5 :=<0Z1S
this("","","",5); e2onR~Cf
} H"_]Hq
q*h1=H52
:=0XT`iY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r%QnV0L^
{ U;QN+fF]u
sSiteURL= sURL; #kuk3}&
sFilePath = sPath; <MPoDf?h
sFileName = sName; )bM #s">Y
this.nSplitter = nSpiltter; D>YbL0K>X~
jMT];%$[
~HR/FGe?N
} (IrX\Y
e>ZF? (a0
h,D6MP
public String getSSiteURL() E2PMcT{)_
{ G?y'<+Awt
return sSiteURL; =t+{)d.w
} SSS)bv8m
Fe4QWB6\U
>/kwy2
public void setSSiteURL(String value) 7=o2$
{ 4/Vy@h"A3
sSiteURL = value; hKT]M[Pv
} N'#Lb0`B
CD]2a@j{
wc-ll&0Z
public String getSFilePath() qlUw;{;p
{ 7jb{E+DrG
return sFilePath; &I[ITp6y0
} I3 %P_oW'
owA0I'|V-A
{GaQV-t
public void setSFilePath(String value) $rZ:$d.C
{ 4zF|}aiQ
sFilePath = value; Wgh4DhAW
} lZ3o3"
<z>K{:+>
.?TPoqs7Z
public String getSFileName() "dKYJ&$
{ $J~~.PUXQ
return sFileName; +Oae3VFf;
} >gt_C'
XZcT-w7
xr2ew%&o
public void setSFileName(String value) u%^Lu.l_c
{ DIk\=[{2q
sFileName = value; NZ\aK}?~!
} "4{_amgm&<
A~vZ}?*M
LE15y>
public int getNSplitter() xLE+"6;W
{ U`j[Ni}"
return nSplitter; brQkVt_)EE
} cI)XXb4
A2`QlhZ
bb6 ~H
public void setNSplitter(int nCount) ;|2h&8yX(/
{ sP0pw]!
nSplitter = nCount; u5f+%!p
} ~urV`J
} :'OCQ.[{s
gyW*-:C
@17hB h
/* q2I;Ly\3o
**Utility.java )P^5L<q>|
*/ 2$D *~~
package NetFox; 7k<4/|CQ{
\ B~9Ue!
o:\RJig<
public class Utility { TtL2}Wdd.%
Jmb [d\ /D
q%4l!gzF3
public Utility() LzEAA{
{ lu^c^p;
{&Kq/sRz
5zlgmCGow
} guC/eSxv
i^{.Q-
//线程睡眠 c<V.\y0x
public static void sleep(int nSecond) r<;bArs-u
{ W{OlJRX8
try{ {IeW~S'&
Thread.sleep(nSecond); U*ZP>Vv
} "y>\ mC
catch(Exception e) 8wz4KG3SK
{ *G^n<p$"
e.printStackTrace (); H|='|k5Y.
} 28[dTsd%
} 29"eu#-Qj
6 ^X$;
//日志 ;Ef:mr"Nu
public static void log(String sMsg) c7j^OP
{ BoB2q(
System.err.println(sMsg); D[)")xiG
} &* 4uji
&XosDt
A>6b 6
public static void log(int sMsg) pti`q)
{ 9i)E<.6
System.err.println(sMsg); LxkToO{
} 0lNVQxG
} 7z \I\8
'sJ=h0d_[V
<^,w,A
/* n4%|F'ma
**TestMethod.java y D.S"
*/ BRP9j y
package NetFox; p6[a"~y
bz_Zk
pb`F_->uq
public class TestMethod { ?;.j)
V *=To
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public TestMethod() uROt h_/
{ ///xx/weblogic60b2_win.exe - Z"w
try{ oC>QJ(o,8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =:aH2T*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L0SeG:
SiteFileFetch fileFetch = new SiteFileFetch(bean); &I.UEF2,
fileFetch.start(); *=L3bBu?
} E%\iNU!
catch(Exception e){e.printStackTrace ();} 0SV#M6`GX
t=iSMe
-@%*~^~z'
} (veGztt
SMaC{RPQ
krZ J"`
public static void main(String[] args) 1)u 3
{ PIo/|1
new TestMethod(); QBa1c-Y
} CzxU @
} .-+_>br~
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