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)); u{Ak:0G7
} $UC{"0
for(int i=0;i<nEndPos.length-1;i++) X3yS5whd(
{ }LQC.!
nEndPos = nStartPos[i+1]; qnXTNs ?b
} |IN[uQ
nEndPos[nEndPos.length-1] = nFileLength; d@ (vg
} AG>\aV"b
} Du!._
yLqF ,pvO
b i~=x
//启动子线程 +GeWg` \=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `*k@4.J{
for(int i=0;i<nStartPos.length;i++) 'Wp@b678
{ dp<$Zw8BE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vBoO'l9'M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9yL6W'B!
nStartPos,nEndPos,i); `ET& VV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oM-[B h]A
fileSplitterFetch.start(); Sc_5FX\Yx
} `HyF_m>\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J^:n* C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M4:s;@qZ.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l!@ 1u^v2
nEndPos = " + nFileLength); (O0byu}
// fileSplitterFetch[nPos.length-1].start(); E}YIWTX
9!#EwPD$#
gr+Pl>C{
//等待子线程结束 M*`hDdS
//int count = 0; $r15gfne>
//是否结束while循环 30d#Lq
boolean breakWhile = false; Mk5RHDh
$3\,h;y
YlKFw|=
while(!bStop) Y.-S=Y
{ T5e^J"
write_nPos(); q.T:0|
Utility.sleep(500); H,K`6HH
breakWhile = true; ?1w"IjUS
ag;dc
FN\GE\H
for(int i=0;i<nStartPos.length;i++) pkk4h2Ah
{ "dtlME{Bx
if(!fileSplitterFetch.bDownOver) $^h?:L:1n
{ Y;_T=L
breakWhile = false; -Qb0:]sV#
break; =/}X$,@2
} /b%Q[ Ck_
} I`^YAbnb
if(breakWhile) }-nU3{1
break; H~Uq?!=b
wOg,SMiq
%{'4. ,
//count++; qqvF-mDN
//if(count>4) A[JM4x
// siteStop(); ir&.Z5=
} #jP/k.
yU_9a[$V
L~&" aF/b
System.err.println("文件下载结束！"); zy>}L #
} .8H}Lf\
catch(Exception e){e.printStackTrace ();} (0C&z/
} AC4 l<:Yh
x~+-VF3/
mi^hvks<
//获得文件长度 S^j,f'2
public long getFileSize() jQ$BPEG&X
{ s|2}2<+
int nFileLength = -1; 0>@[o8
try{ $$4W}Ug3U
URL url = new URL(siteInfoBean.getSSiteURL()); c-*2dV[@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6+PGwCS
httpConnection.setRequestProperty("User-Agent","NetFox"); (h,Ws-O
<L&eh&4c
F,pCR7o>
int responseCode=httpConnection.getResponseCode(); [:B*6FXMN~
if(responseCode>=400) 88o:NJ}_
{ m UgRm]
processErrorCode(responseCode); XTo8,'UaP
return -2; //-2 represent access is error E{>`MNj
} GV6mzD@<
q-IWRb0j%a
m =k%,J_
String sHeader; F1c&0*_A
I%xn,u
Xw^X&Pp
for(int i=1;;i++) &t_h'JX&
{ c#pj:f*H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o^GC=Aca`
//Utility.log(in.readLine()); 1JeJxzv>C
sHeader=httpConnection.getHeaderFieldKey(i); [hnK/4!
if(sHeader!=null) r\xXU~$9v
{ KY+]RxX
if(sHeader.equals("Content-Length")) o0`q#>7!_b
{ j04/[V)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GAp!nix6h
break; LdEE+"Jw
} /^4"Qv\@/
} VQ<5%+
else VGZ6
break; UH20n{_:
} Ub)M*Cq0(o
} aQ|hi F}
catch(IOException e){e.printStackTrace ();} 8*Zvr&B,G
catch(Exception e){e.printStackTrace ();} tIGs>, a=
M&[b.t*
F$yeF^\g
Utility.log(nFileLength); Pux)>q] C
@T7PZB&xnl
c<tmj{$
return nFileLength; :e2X/tl#
} 968^"T#
Eem g
$?f]ZyZr.
//保存下载信息（文件指针位置） =P]GPEz_
private void write_nPos() 5~l2!PY
{ PEzia}m
try{ gZ`DT
output = new DataOutputStream(new FileOutputStream(tmpFile)); `bqzg
output.writeInt(nStartPos.length); |Fp'/~|w2d
for(int i=0;i<nStartPos.length;i++) 7I3:u+
{ .bfST.OA
// output.writeLong(nPos); H,|YLKg-|
output.writeLong(fileSplitterFetch.nStartPos); b:Dg}
output.writeLong(fileSplitterFetch.nEndPos); / O)6iJ
} >{XScxaB`
output.close(); %wW'!p-<
} >'Hx1;
catch(IOException e){e.printStackTrace ();} -u~eZ?(!Ye
catch(Exception e){e.printStackTrace ();} /qXzOd
} xA-jvu9@
0;cuX@A/a?
OX3Xy7
//读取保存的下载信息（文件指针位置） Ja [#[BJ?
private void read_nPos() FL&dv
{ ImHU:iR[J-
try{ a}yR p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VDn:SGj5
int nCount = input.readInt(); )7AM3%z1?
nStartPos = new long[nCount]; <kbnu7?a*
nEndPos = new long[nCount]; q+%!<]7X
for(int i=0;i<nStartPos.length;i++) MYx88y
{ 4)nt$fW
nStartPos = input.readLong(); aAcKwCGq\
nEndPos = input.readLong(); 3:AU:
} #90c$ dc
input.close(); 1eiw3WU;
} -0DZ::
catch(IOException e){e.printStackTrace ();} h2;l1G,
catch(Exception e){e.printStackTrace ();} QgZJ`G--
} vJThU$s-
?*+1~m>
3#mE( `|P
private void processErrorCode(int nErrorCode) [gn[nP9
{ vHc#m@4o
System.err.println("Error Code : " + nErrorCode); {u4i*udG`)
} `^%@b SE(
"XB4yExy
w%2ziwgh
//停止文件下载 UR,?!rJ^B
public void siteStop() ^U{P3%uZ
{ ;@4sd%L8V
bStop = true; vX.]hp5~
for(int i=0;i<nStartPos.length;i++) )Ga8`t"
fileSplitterFetch.splitterStop(); PW)8aLU
6sy,A~e
.hne)K%={y
} qK-qcPLsl
} L!vWRwZwC
//负责部分文件的抓取 K0 QH?F
**FileSplitterFetch.java +.K*n&
*/ S}mm\<=1
package NetFox; CjV7q y
$eMK{:$O
eI?HwP{m
import java.io.*; zzE]M}s
import java.net.*; b"3uD`
y($EK(cb
3P`WPph
public class FileSplitterFetch extends Thread { G<fS(q
wt\m+!u`
tNB%eb{
String sURL; //File URL =h7[E./U1
long nStartPos; //File Snippet Start Position |?yE^$a
long nEndPos; //File Snippet End Position xD^wTtT
int nThreadID; //Thread's ID pJ6Jx(
boolean bDownOver = false; //Downing is over Rdj8*f
boolean bStop = false; //Stop identical ?sE@]]z
FileAccessI fileAccessI = null; //File Access interface {83C,C-
O!,Ca1N
UQnBqkE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jm+blB^%K
{ jJ<;2e~OW
this.sURL = sURL; +K&?)?/=
this.nStartPos = nStart; *?p ^6vO
this.nEndPos = nEnd; [9J:bD
nThreadID = id; r;'i<t{P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sX!3_'-
} Wt"ww~h`(
z6 a,0&;-L
Q!`)e@r
public void run() iel-<(~
{ nfa_8
while(nStartPos < nEndPos && !bStop) [\a:4vDAbi
{ cB<O.@
|zh +
|+u+)C
try{ ot0U-G(
URL url = new URL(sURL); A`IHP{aB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \*Ts)EW
httpConnection.setRequestProperty("User-Agent","NetFox"); &M$Bt} <
String sProperty = "bytes="+nStartPos+"-"; yYM_lobn
httpConnection.setRequestProperty("RANGE",sProperty); r(]98a]o~
Utility.log(sProperty); _tA7=*@8
%6N)G!P
S7Znz@
InputStream input = httpConnection.getInputStream(); C_-%*]*,j
//logResponseHead(httpConnection); drbe#FObX
6N&|2:U
ovB=Zm
byte[] b = new byte[1024]; CuIqh BW!
int nRead; f&f`J/(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9QC< E|
{ .(JE-upJ"
nStartPos += fileAccessI.write(b,0,nRead); hRa\1Jt>a
//if(nThreadID == 1) jmSt?M0.xV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!i,?vn
} Etw~*
& \JLTw
4`$5 _} j!
Utility.log("Thread " + nThreadID + " is over!"); O/(3 87=U
bDownOver = true; Shs')Zsbv
//nPos = fileAccessI.write (b,0,nRead); nT#37v
} &yB%QX{3
catch(Exception e){e.printStackTrace ();} =,O/,2)
} g%ZdIKj!
} Bj; [
UmYD]
1E8$% 6VV
//打印回应的头信息 /9P^{OZ;y
public void logResponseHead(HttpURLConnection con) A0S8Dh$
{ 6={IMkmA
for(int i=1;;i++) RXUA!=e
{ 7,f:Qi@g
String header=con.getHeaderFieldKey(i); PBCb0[\
if(header!=null) J_|7$ l/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4C6=77Jr
Utility.log(header+" : "+con.getHeaderField(header)); =Y/}b\9`T
else q)NXyy4BT
break; DQ%`v=
} c!.=%QY
} K4_~ruhr
N`f!D>b:dn
Rq"VB.ef&{
public void splitterStop() dJloH)uJZ>
{ Ih(:HFRMq6
bStop = true; $|rCrak;
} ={\![{L
fBf]4@{
C?8PT/
} I; ^xAd3G
3T"2S[gT
VIb;96$Or
/* 92s4u3L;
**FileAccess.java BO[+E'2
*//文件访问(定位，写) @8QFP3\1
package NetFox; R_t~UTfI;
import java.io.*; "tfn?n0
yVT&rQ"{
hJecCOA)'
public class FileAccessI implements Serializable{ >9 q]>fJ
G!nl'5|y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mp!YNI
RandomAccessFile oSavedFile; <}<#W/
long nPos; km9Gwg/zT
SRP5P,-y
nWKO8C>
public FileAccessI() throws IOException ,m2A p\l
{ hT.4t,wa8
this("",0); EV:_Kx8fP
} Vp|2wlFE-
0Ulxp
:8](&B68gE
public FileAccessI(String sName,long nPos) throws IOException @m5O{[euj<
{ (}9cD^F0n
oSavedFile = new RandomAccessFile(sName,"rw"); $$k7_rs
this.nPos = nPos; r5D jCV"
oSavedFile.seek(nPos); <9=zP/Q
} X'YfjbGo
n>u.3wL
wYZye^7
public synchronized int write(byte[] b,int nStart,int nLen) W/b"a?wE{
{ s.f`.o
int n = -1; d&/^34gn
try{ )C'G2RV
oSavedFile.write(b,nStart,nLen); X7t5b7
n = nLen; =9kj? u~
} ]\[m=0K
catch(IOException e) jn.R.}TT
{ @<hF.4,]
e.printStackTrace (); ;gZwQ6)i
} 2b; rr
&r&;<Q
V*~1,6N[
return n; ,h3269$J
} J@oEV=L
?R dmKA
='7er.~\
} K#_~ !C4L
:&xz5c`"04
83mlZ1jQz
/* ev~dsk6k
**SiteInfoBean.java m"96:v
*/ $Sp*)A]E`
package NetFox; !Sh^LYqn
b7?U8/#'
p>2||
public class SiteInfoBean { 59&T/
ST[2]
9zXu6<|qrL
private String sSiteURL; //Site's URL ^</65+OT+
private String sFilePath; //Saved File's Path 'CP/ymf/a
private String sFileName; //Saved File's Name b=6MFPbg
private int nSplitter; //Count of Splited Downloading File SZCF3m&pz
aO~si=
%1Vu=zCAW
public SiteInfoBean() v[0DE*p
{//nSplitter的缺省值为5 E"Ya-8d=
//default value of nSplitter is 5 kWzuz#
this("","","",5); jlYD~)
} )2iM<-uB
A8=e?%
[5>S-Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \[Sm2/9v
{ s`$NW^']
sSiteURL= sURL; =gxgS<bde
sFilePath = sPath; 4^d+l.F
sFileName = sName; <_##YSGh,
this.nSplitter = nSpiltter; _myg._[
F Q8RK~?`
xi '72
} ti$oZ4PpF
N&6_8=3z
Z7tU0
public String getSSiteURL() .`oJcJ
{ b&\3ps
return sSiteURL; jF%)Bhn(
} r Iya\z1W
@4 zi]v
I-RdAVB/Ep
public void setSSiteURL(String value) D6&mf2'u
{ FRl3\ZDqrb
sSiteURL = value; 'hwV
} U%mkhWn
[}W^4,
6F|Hg2tpz
public String getSFilePath() DFt=%aV[
{ _hAj2%SL
return sFilePath; 0EL\Hd
} ({;P#qCX
7\7Brw4
yt/20a
public void setSFilePath(String value) 6%\7.h
{ SREDM
sFilePath = value; Tf&f`/
} `jD8(}_
/|4Q9=
OqfhCNAY
public String getSFileName() Bo\a
{ WUE)SVf
return sFileName; ^kCk^D-Gz
} 'Z*\1Ci
u)q2YLK8
e3yorQ][
public void setSFileName(String value) KuIt[oM
{ e.)yV'%L
sFileName = value; }};j2
} 1kB'sc3N!
SQO>}#qm
Bi9 N
public int getNSplitter() { 4_I7r
{ d-6sC@PB
return nSplitter; ,wwU` U
} f7EIDFX>pt
&^CL]&/
2.fyP"P L
public void setNSplitter(int nCount) T[Z <bW~0
{ 2]of SdM
nSplitter = nCount; ,XWay%8{E
} G"T;l"TAt8
} ,\sR;=svK
w6WGFQ_%
R`Ys;g/!
/* <;$Sa's,LE
**Utility.java :wv :#EaH
*/ _1w.B8Lyz@
package NetFox; E)&NP}k-P
1=9qAp;?o
r+{!@`dYi
public class Utility { #hy5c,}>
ugIm:bg&
38x[Ad4%
public Utility() ^D]7pe
{ ~>}dse
U<ku_(2"#
mr{k>Un\
} Y0P}KPD
bl:a&<F
//线程睡眠 ZXssvjWQV}
public static void sleep(int nSecond) 4*N@=v
{ [3{:H"t
try{ M(.uu`B
Thread.sleep(nSecond); )[y!m9Vn
} JqVBT+:
catch(Exception e) _H^^2#wc/
{ HobGl0<y
e.printStackTrace (); N[+o[%A
} |?;"B:0
} ohQz%?r
YO.`l~ v
//日志 Y5h)l<P>B
public static void log(String sMsg) ]HNT(w@
{ )M&Azbu
System.err.println(sMsg); }2iKi(io*
} +YQ)}v
#"=yQZ6Y
MYDf`0{$_a
public static void log(int sMsg) (x1"uy7_
{ k$$S!qi#
System.err.println(sMsg); 0]:*v?
} J-eA,9J
} 9:CVN@E
J]=aI>Ow
3%vx'1h[
/* ?vht~5'
**TestMethod.java T(sG.%
*/ 1eE]4Z4Q
package NetFox; JhMrm%
$.r}g\43P
X_0{*!v8
public class TestMethod { oSu|Yn
Ru9pb~K
6?<`wGs(
public TestMethod() , IMT '*
{ ///xx/weblogic60b2_win.exe EvH(Po h
try{ 7b7%(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (_%JF[W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $dVgFot
SiteFileFetch fileFetch = new SiteFileFetch(bean); hZss
fileFetch.start(); G +nY}c
} [kp7LA"`
catch(Exception e){e.printStackTrace ();} %CsTB0Y7n,
HAI1%F236
Q8gdI
} JX2 |
b]so9aCz
"b1R5(Ar
public static void main(String[] args) K;ry4/Vap
{ ^;bGP.!p
new TestMethod(); 35@Ibe~
} e%@[d<Ta\
} 4s1kZ`e
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