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)); U2r[.Ru
} O1@3V/.Wu
for(int i=0;i<nEndPos.length-1;i++) riF-9 %i
{ ]UkqPtG;
nEndPos = nStartPos[i+1]; ^6gEL~m|]
} t33\f<e
nEndPos[nEndPos.length-1] = nFileLength; n%;4Fm?
} {Hie%2V
} *~~J1.ja>
Dm%Q96*VAq
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//启动子线程 JqUft=p5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0 .UN
for(int i=0;i<nStartPos.length;i++) baBPf{<
{ Q;ZV`D/FA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e7y,zcbv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SQ*%d.1
nStartPos,nEndPos,i); ._]*Y`5)d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m70AWG
fileSplitterFetch.start(); .+mP#<mAg
} 1,:QrhC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aeVd.`lxM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QL @SE@"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #)m[R5g(
nEndPos = " + nFileLength); Em4'b1mDX%
// fileSplitterFetch[nPos.length-1].start(); H?eG5
2c51kG77E
DxD\o+:r
//等待子线程结束 lD'^6
//int count = 0; vTo+jQs^
//是否结束while循环 A>,kmU5
boolean breakWhile = false; |'lNR)5
-aLM*nIoe
fu{v(^
while(!bStop) vM-kk:n7f
{ AHMvh 7O?
write_nPos(); S?zP; iFj
Utility.sleep(500); [0 rH/{
breakWhile = true; >sdF:(JV&
#S]O|$&*
*%\Xw*\0
for(int i=0;i<nStartPos.length;i++) Xgl %2'
{ mhM;`dl
if(!fileSplitterFetch.bDownOver) Y O|hwhe_
{ R%~~'/2V
breakWhile = false; #V)l>
break; W9{;HGWS
} -tx%#(?wH
} c(29JZ
if(breakWhile) I %sw(uoE
break; "$b{EYq6
Zl>wWJ3y
V lkJ$f5l
//count++; C^LxJG{L5
//if(count>4) 4]E1x l
// siteStop(); _j4K
} +K8T%GAr
9':Hh'
,$aqF<+;
System.err.println("文件下载结束！"); zlB[Eg^X
} v9!]/]U^
catch(Exception e){e.printStackTrace ();} ,-kz\N@.
} M04u>| ,
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=*.S<Ko)
//获得文件长度 /cVZ/"
public long getFileSize() vR pO0qG
{ Q<DXDvL
int nFileLength = -1; >s!k"s,
try{ Y9 Bk$$#\
URL url = new URL(siteInfoBean.getSSiteURL()); xT( pB-R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z).&0K
httpConnection.setRequestProperty("User-Agent","NetFox"); fh66Gn,
4#t=%}
Gm> =s
int responseCode=httpConnection.getResponseCode(); I~E&::,
if(responseCode>=400) |Om9(xT
{ z_#HJ}R=
processErrorCode(responseCode); /1m+iM^V
return -2; //-2 represent access is error E(z|LS*3
} t?b@l<,s
<[T{q |*
$VP\Ac,!
String sHeader; I)9,
VV#'d
#)i+'L8
for(int i=1;;i++) 6OJhF7\0&
{ XWX]/j2jA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DwK$c^2q{.
//Utility.log(in.readLine()); {$pi};
sHeader=httpConnection.getHeaderFieldKey(i); 4H@7t,>
if(sHeader!=null) b7">IzAe
{ Lo Y*,Aa&
if(sHeader.equals("Content-Length")) (=Oo=8\
{ pV!WZUfg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2|(lKFkQ
break; K@oyvJ$
} }7K~-
} [\%a7ji#
else 7AqbfLO
break; E70o nR!i
} J l{My^I5
} e2>AL
catch(IOException e){e.printStackTrace ();} >5TXLOYZ
catch(Exception e){e.printStackTrace ();} )4hA Fy6l
.81 ~ K[
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Utility.log(nFileLength); %h;1}SFl0
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|+JC'b?,
return nFileLength; ccx0aC3@I
} bj_/
Z.rhM[*+0C
>z%WW&Z'
//保存下载信息（文件指针位置） ~BE=z:
private void write_nPos() :~ &#9
{ tO D}&
try{ fQ-IM/z
output = new DataOutputStream(new FileOutputStream(tmpFile)); *+00
output.writeInt(nStartPos.length); oMYZ^b^
for(int i=0;i<nStartPos.length;i++) ixoN#'y<"
{ 7{k?"NF
// output.writeLong(nPos); SL\15`[{
output.writeLong(fileSplitterFetch.nStartPos); CL?=j| Ea
output.writeLong(fileSplitterFetch.nEndPos); &Z9rQH81f>
} Po.by~|
output.close(); e? |4O<@
} !CY*SGO
catch(IOException e){e.printStackTrace ();} W'Y(@
catch(Exception e){e.printStackTrace ();} ~zvZK]JoX
} "5Z5x%3I
vIZFI
lS!O(NzqE'
//读取保存的下载信息（文件指针位置） 2^Z"4t4
private void read_nPos() nU6UjC|3
{ u@`y/,PX
try{ Df]*S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oh9L2"
int nCount = input.readInt(); >7cDfv"
nStartPos = new long[nCount]; E}#&2n8Y
nEndPos = new long[nCount]; LWN9 D
for(int i=0;i<nStartPos.length;i++) ;E!] /oY<
{ YM.
nStartPos = input.readLong(); G c,
nEndPos = input.readLong(); aN6HO
} :o~]d
input.close(); SP>&+5AydX
} N-Bw&hEZ
catch(IOException e){e.printStackTrace ();} K!2%8Ej,J
catch(Exception e){e.printStackTrace ();} w6-<HPW<S
} 3a}c'$F>_'
!\OX}kHX5
*_HF%JYMZ
private void processErrorCode(int nErrorCode) # $'H?lO
{ QBfo=9[=e
System.err.println("Error Code : " + nErrorCode); -3m!970
} t8.3
|eJR3o
I SdB5Va
//停止文件下载 Im]6-#(9\|
public void siteStop() @~&^1%37)
{ gkca{BJ
bStop = true; qagR?)N)u
for(int i=0;i<nStartPos.length;i++) ]mC5Z6,1s
fileSplitterFetch.splitterStop(); >McEuoZx9
5dbj{r)s6i
ov >5+"q)
} K*p3#iB
} 3BF3$_u)o
//负责部分文件的抓取 ^oClf(
**FileSplitterFetch.java _~}2@&*G"
*/ J: I@kM
package NetFox; h}DKFrHW;-
S&D8Rao5
N&|,!Cu
import java.io.*; gr# |ZK.`
import java.net.*; s3K!~v\L]
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k/BlkjlNE
public class FileSplitterFetch extends Thread { lvLz){
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T`]P5Bk8r
String sURL; //File URL k[f_7lJ2
long nStartPos; //File Snippet Start Position oR3t vw.
long nEndPos; //File Snippet End Position CW.T`F
int nThreadID; //Thread's ID !;${2Q
boolean bDownOver = false; //Downing is over ocZ^rqo2w
boolean bStop = false; //Stop identical [N<rPHT
FileAccessI fileAccessI = null; //File Access interface +c__U Qx
L@ejFXQg
\Xr*1DI<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A8:eA
{ )HX(-"c
this.sURL = sURL; Y.#fpG'
this.nStartPos = nStart; 10bv%ZX7
this.nEndPos = nEnd; ktp<o.f[
nThreadID = id; 8PWEQ<ev7>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HK%W7i/k@
} j[dgY1yE:
)l`VE_(|
0ZZ Wj%
public void run() wyLyPJv
{ \eRct_
while(nStartPos < nEndPos && !bStop) /Ba/gq0j
{ *>xCX
6` Aw!&{
1jaK N*
try{ cIP%t pTW.
URL url = new URL(sURL); +*aC \4w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _1~pG)y$U
httpConnection.setRequestProperty("User-Agent","NetFox"); Vjd>j; H
String sProperty = "bytes="+nStartPos+"-"; Tk`|{Ph0
httpConnection.setRequestProperty("RANGE",sProperty); wrsr U
Utility.log(sProperty); JC;&]S.
_~S[
%joU}G;"
InputStream input = httpConnection.getInputStream(); 7<Y aw,G
//logResponseHead(httpConnection); =F %lx[9Ye
rd)W+W9
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byte[] b = new byte[1024]; =1<v1s|)q
int nRead; wxT(ktE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QV4FA&f&
{ 4=N(@mS
nStartPos += fileAccessI.write(b,0,nRead); 0sB[]E|7[s
//if(nThreadID == 1) a|4Q6Ycu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'rA(+-.M;
} 62K#rRS
tJ&tNSjTi
qVjMflVoay
Utility.log("Thread " + nThreadID + " is over!"); h 9}x6t,
bDownOver = true; >2X-98,
//nPos = fileAccessI.write (b,0,nRead); IaU%L6Q]
} & x_ #zN]
catch(Exception e){e.printStackTrace ();} Eh$1piJG
} cH+ ~|3
} hML-zZ
0Q)YZ2
k|U2Mp
//打印回应的头信息 Fh|{ib
public void logResponseHead(HttpURLConnection con) DKkilqVM
{ :T<5Tq*+x
for(int i=1;;i++) hVui.]
{ .N`*jT
String header=con.getHeaderFieldKey(i); T)',}=
if(header!=null) Ba**S8{/`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :\y' ?d- Q
Utility.log(header+" : "+con.getHeaderField(header)); JV_VM{w{K
else f[ia0w5 m
break; 4yjIR?
} \k^ojzJ
} 8 VhU)fY
g!9|1z
l,zhBnD
public void splitterStop() I0!]J{
{ $g/h=w@
bStop = true; e+MQmWA'F
} yrd1J$
vTTXeS-b
T k@~w
} 4S[UJ%
e6^}XRyf
4IvT}Us#+
/* n 8 K6m(
**FileAccess.java nd7g8P9p
*//文件访问(定位，写) a,r B7aD
package NetFox; &~2IFp
import java.io.*; K9y~ e
TPak,h(1
j-.Y!$a%6
public class FileAccessI implements Serializable{ ]hoq!:>M1
k+vfZ9bD(J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WjCxTBI
RandomAccessFile oSavedFile; A7|L|+ ?
long nPos; "F6gV;{Bt
/bPs0>5
#<EYO
public FileAccessI() throws IOException SvrUXf
{ JbQY{z!
this("",0); -Mz[S
} DUh\x>^
1ANb=X|hig
0/9]TIc
public FileAccessI(String sName,long nPos) throws IOException m^=El7+
{ N/--6)5~0
oSavedFile = new RandomAccessFile(sName,"rw"); Z!7xRy
this.nPos = nPos; 8/&4l,M5
oSavedFile.seek(nPos); >?rMMR+A
} F=e-jKogK
v+8Ybq
K1Uq`TJ
public synchronized int write(byte[] b,int nStart,int nLen) L(sT/
{ 5t"FNL <(M
int n = -1; c&FOt
try{ !a-B=pn!]
oSavedFile.write(b,nStart,nLen); 0!7p5
n = nLen; ! Dj2/][
} V; CPn
catch(IOException e) S!+>{JyQ
{ y@It#!u0
e.printStackTrace (); w( _42)v]g
} bLAHVi<.
2#r4dr0
:tI F*pC
return n; akU2ToP
} 4^M"V5tDx
:O$bsw:3w<
>#k- ~|w
} ^YropzHZ4E
&i.sSqSI5
7GWOJ^)
/* y&-QLX L
**SiteInfoBean.java nosD1sS.K8
*/ B4wRwrVI>
package NetFox; [~2imS
j49Uj}:j
$LFL4Q
public class SiteInfoBean { ]bY]YNt{7]
(QJe-)0_y
rp{|{>'`.q
private String sSiteURL; //Site's URL x3Y)l1gh
private String sFilePath; //Saved File's Path dRnf
private String sFileName; //Saved File's Name XWyP'\
private int nSplitter; //Count of Splited Downloading File \Z&Nd;o
-THMTRFz
'A3skznX{
public SiteInfoBean() J}:.I>
{//nSplitter的缺省值为5 lM{fld
//default value of nSplitter is 5 xZlCFu
this("","","",5); +38R#2JV
} -!:5jfT"
#mA(x@:*
OTdijQLY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AyOibnoZ2E
{ T9H*]LxK
sSiteURL= sURL; L/V^#$
sFilePath = sPath; });Rjg
sFileName = sName; 2R.LLE
this.nSplitter = nSpiltter; _Uq' N0U
<.B+&3')
Mjy:k|aY"
} a4=(z72xe
S!.&#sc
I4{xQI
public String getSSiteURL() Cul=,;pkB
{ ow.!4kx{d
return sSiteURL; wz*iwd-
} (Y@T5-!D
$?G@ijk,
4]ni-u0*
public void setSSiteURL(String value) E<[ s+iX
{ }|Mwv $`
sSiteURL = value; yy7(')wKO
} .t5.(0Xk[A
;54NQB3L
e12QYoh
public String getSFilePath() ,_I rE
{ <78|~SKAV
return sFilePath; _wS=*-fT
} (^m] 7l
0f.jW O
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public void setSFilePath(String value) yJq<&g
{ y]m: {
sFilePath = value; bj`\;_oo
} kz7FQE
VTM* 1uXS>
:aej.>I0
public String getSFileName() |JxVfX8^
{ 9Yv:6@.F
return sFileName; VP~2F E
} d?2ORr|m=
)Y7H@e\1
5M0Q'"`F:
public void setSFileName(String value) L(VFzPkY%
{ bOFzq>k_
sFileName = value; &aLTy&8Fv
} D}98ZKi
30!DraW8
(WyNO QO'
public int getNSplitter() l<f9$l^U
{ 25$_tZPAI
return nSplitter; _SAM8!q4,
} ,X4+i8Yc
[-])$~WfW
h*k V@Dc
public void setNSplitter(int nCount) oS fr5 i
{ c\{N:S>
nSplitter = nCount; ` kT\V'
} *c$[U{Px
} EfrQ~`\
olE(#}7V
u ]e-IYH
/* &Q883A J
**Utility.java w\bwa!3Y
*/ Jr2yn{s=S
package NetFox; GfE>?mG
0Z1ksfLU
ES~b f
public class Utility { ""0Y^M2I
Rql/@j`JX
ga5Q
public Utility() 9\_AB.Z:
{ g"m' C6;
Zv;nY7B
h;gc5"mG
} {aY) Qv}
l{{,D57J
//线程睡眠 TTz=*t+D
public static void sleep(int nSecond) ]y_:+SHc
{ Z-PBCU
try{ '~D4%WKT
Thread.sleep(nSecond); $0_K&_5w~
} %Jt35j@Ee
catch(Exception e) i%K6<1R;y{
{ 3^7+fxYWo
e.printStackTrace (); oMQ4q{&|
} z1J)./BO
} IA2VesHb
\,Y .5?
//日志 8G:/f3B=
public static void log(String sMsg) msBoInhI
{ MzIDeZ
System.err.println(sMsg); d@R7b^#g
} E(~7NRRm
4&mY-N7A
JbPkC*.
public static void log(int sMsg) dy&G~F28
{ ,hn#DJ)
System.err.println(sMsg); 72dRp!JU
} z &EDW5I
} &=g3J4$z
:#YC_ id
nn7LL+h
/* Q,KNZxT,q
**TestMethod.java 6!\V|
*/ ywwA,9~
package NetFox; |Ea%nghl
Hr?lRaV
A8'RM F1
public class TestMethod { ^Arv6kD,
`MI\/oM@
x%viCkq
public TestMethod() Z/q6Q#
{ ///xx/weblogic60b2_win.exe yB UQ!4e
try{ m!FuC=e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u7< +)6-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nwFBuP<LR
SiteFileFetch fileFetch = new SiteFileFetch(bean); MQoA\
fileFetch.start(); \zBi-GI7
} d$$5&a
catch(Exception e){e.printStackTrace ();} {=GmXd%D
_ $F=A
w+)${|N?
} <:9ts@B
w6vbYPCN
KuJ)alD;1
public static void main(String[] args) }4C_r'd6
{ 1-y8Hy_a2
new TestMethod(); |T<aWZb^=
} :h(HKMSk1
} ?X|)0o
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