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)); GlQ=M)E
} ]y.,J
for(int i=0;i<nEndPos.length-1;i++) 2=F_<Jh|+
{ ;PG'em
nEndPos = nStartPos[i+1]; f=}u;^
} rAP+nh ans
nEndPos[nEndPos.length-1] = nFileLength; mUcHsCszH
} Dih~5
} `1M_rG1/+
5jx{O${u
gJvc<]W8!
//启动子线程 *DDfdn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D!qtb6<.
for(int i=0;i<nStartPos.length;i++) WYEvW<Hv
{ <XCH{Te1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MW'z*r|,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O!Mm~@MoA
nStartPos,nEndPos,i); #z~D1Zl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YwB5Zqr
fileSplitterFetch.start(); .}Bb :*@
} K8284A8v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g.F{yX]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (z^2LaM `8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b$rBxe\
nEndPos = " + nFileLength); t MA
// fileSplitterFetch[nPos.length-1].start(); #'$CC<*vy
]r|.\}2Y7
>;0z-;k6
//等待子线程结束 EMJio\
//int count = 0; @Q TG
//是否结束while循环 QWfwoe&;R:
boolean breakWhile = false; &Sc0l/
e|]g?!
>TK`s@jdSV
while(!bStop) Fda<cS]
{ Q7`zrCh
write_nPos(); 2t#9ih"9
Utility.sleep(500); scN}eg:5
breakWhile = true; &X +@,!
RC\TPG/8!
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for(int i=0;i<nStartPos.length;i++) {s_0[>
{ X9zTz2 Fy
if(!fileSplitterFetch.bDownOver) 'pZ~3q
{ m,]Tl;f
breakWhile = false; $c f?`k
break; dI'C[.zp[
} )M^;6S
} #`}g?6VHo
if(breakWhile) 0D0#*J
break; ;?%2dv2d
PMkwY{.u
Dt.OZ4w5
//count++; bNIT 1'v
//if(count>4) H+_oK ]/
// siteStop(); %3"3OOT7
} 9.PY49|
/sJk[5!z
:sM|~gT
System.err.println("文件下载结束！"); nef-xxXC^I
} 28Q`O$=v
catch(Exception e){e.printStackTrace ();} 5F&i/8Ib
} JEFW}M)UGv
r|0C G^:C
iHQFieZ.E
//获得文件长度 _VR4|)1g
public long getFileSize() x7{,4js
{ } vcr71u
int nFileLength = -1; 0Wv9K~F
try{ hFQC%N.'
URL url = new URL(siteInfoBean.getSSiteURL()); KGK8;Q,O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +$8hTi,
httpConnection.setRequestProperty("User-Agent","NetFox"); "B)DX*-\?
:UFf6T?
PS \QbA
int responseCode=httpConnection.getResponseCode(); @RT yCr
if(responseCode>=400) Fd|:7NRA<
{ "fz-h
processErrorCode(responseCode); c WK@O>
return -2; //-2 represent access is error 4+l7v?:Pr
} 9HP)@66
?86h:9
MQR2UK(
String sHeader; .%~ L
&QCqaJ-
SHz& o[u
for(int i=1;;i++) ;zz"95X7
{ `Gsh<.w!7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x2|DI)J1'
//Utility.log(in.readLine()); Mzxz-cE
sHeader=httpConnection.getHeaderFieldKey(i); /R@(yT=t
if(sHeader!=null) x1A^QIuxO
{ ,{zvGZ|
if(sHeader.equals("Content-Length")) Z AZQFr'*
{ Nnv&~D>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rKi)VVkx_
break; j-yD;N
} a$9UUH-|
} ,9W0fm\t
else j:{<
break; wiwJD}3h'
} ocL
} 5O)Z}
catch(IOException e){e.printStackTrace ();} G-,PsXSwe
catch(Exception e){e.printStackTrace ();} TD\QX2m
mHw1n=B
#gsAwna3
Utility.log(nFileLength); _);1dcnR
.fQDj{
d@#=cvW
return nFileLength; n7{1m$/
} QKHmOVh]
Y]P $|JW):
-4GSGR'L&y
//保存下载信息（文件指针位置） (S9"(\A
private void write_nPos() ts9N$?0:V
{ i<%(Z[9Lk
try{ /vU9eh"%
output = new DataOutputStream(new FileOutputStream(tmpFile)); Do2y7,jv
output.writeInt(nStartPos.length); bM;tQ38*
for(int i=0;i<nStartPos.length;i++) ZO0_:T#Z
{ rEddX
// output.writeLong(nPos); mP:mzmUw
output.writeLong(fileSplitterFetch.nStartPos); 94K;=5h
output.writeLong(fileSplitterFetch.nEndPos); dcXtT3,kpX
} guFR5>-L
output.close(); C'zMOR6c
} p8F|]6Z
catch(IOException e){e.printStackTrace ();} H<1C5-
catch(Exception e){e.printStackTrace ();} tK8\Ib J
} +Pa!pj/< z
sy>Pn
p&ow\AO
//读取保存的下载信息（文件指针位置） ^!kvgm<{$
private void read_nPos() b[BSUdCB
{ drb_GT
try{ q:?g?v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %iJ6;V4
int nCount = input.readInt(); h]MSjC.X
nStartPos = new long[nCount]; ?$r+#'asd(
nEndPos = new long[nCount]; ! '2'db
for(int i=0;i<nStartPos.length;i++) ]~a!O
{ ;>Z#1~8
nStartPos = input.readLong(); hXMC!~Th
nEndPos = input.readLong(); SkPv.H0Id
} ?(g kkYI
input.close(); av`b8cGg
} qTffh{q V
catch(IOException e){e.printStackTrace ();} %*jpQOw
catch(Exception e){e.printStackTrace ();} EH,uX{`e
} I s8|
sav2.w
~vF.k,
private void processErrorCode(int nErrorCode) QjQJ "
{ B]]M?pS
System.err.println("Error Code : " + nErrorCode); ?*4]LuK6
} zIdQ^vm8Q
W^yF5
tQwbIX-7/
//停止文件下载 ~zRW*pd
public void siteStop() qqkZbsN
{ V8,$<1Fi;-
bStop = true; "KFCA9u-
for(int i=0;i<nStartPos.length;i++) 7:1Hgj(
fileSplitterFetch.splitterStop(); z<AQ;b
nLQ X?:
ShSh/0
} .Hgiru&
} OSSMIPr
//负责部分文件的抓取 5[Q44$a{
**FileSplitterFetch.java 8PQ$X2)
*/ PE4{;|a }
package NetFox; e?f[t*td
!N)oi$T%
F.@yNr"
import java.io.*; j"YJ1R-5
import java.net.*; >,~JQ%1
2b3*zB*@V
Y %<B,3
public class FileSplitterFetch extends Thread { Ebq5P$
}4bwLO
_ROe!w 1
String sURL; //File URL (:hPT-1
long nStartPos; //File Snippet Start Position q.g!WLiI
long nEndPos; //File Snippet End Position 9Y/c<gbY
int nThreadID; //Thread's ID *, {b]6v
boolean bDownOver = false; //Downing is over 0~FX!1;
boolean bStop = false; //Stop identical ?rv+ydR/q
FileAccessI fileAccessI = null; //File Access interface G=b`w;oL:
>\>HRyt%
*1elUI2Rg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [IHT)%>E8&
{ J0s8vAs
this.sURL = sURL; 8, WQ}cC
this.nStartPos = nStart; F<^,j7@
this.nEndPos = nEnd; 8`^I.tD
nThreadID = id; ,q:6[~n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 31bKgU{
} 1x\%VtO>\b
!UgJ^v
Q2Q`g`*O:
public void run() <89js87
{ R)<>} y
while(nStartPos < nEndPos && !bStop) ;Y)?6^"
{ zlXkD~GV
"+)ey>_
s2d;601*b
try{ YjsaTdZ!&
URL url = new URL(sURL); 9|OQHy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qkR.{?x
httpConnection.setRequestProperty("User-Agent","NetFox"); Tl25t^Y
String sProperty = "bytes="+nStartPos+"-"; 5g/WQo\
httpConnection.setRequestProperty("RANGE",sProperty); y`\/eX
Utility.log(sProperty); O'!k$iJNb
vK$T$SL
SmtH2%yI
InputStream input = httpConnection.getInputStream(); ,a?em'=
//logResponseHead(httpConnection); %VwB ?
#xts*{u-#
x9@%L{*
byte[] b = new byte[1024]; ;GvyL>|-~
int nRead; hz )L+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (6.0gB$aTu
{ 6o{anHBB
nStartPos += fileAccessI.write(b,0,nRead); ,@[Q:fY
//if(nThreadID == 1) gp$+Qd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )6!SFj>.O
} N;ssO,
RtF_p {s
f\|33)k
Utility.log("Thread " + nThreadID + " is over!"); ch< zpo:
bDownOver = true; C\}m_`MR
//nPos = fileAccessI.write (b,0,nRead); Ebp8})P/~
} 3xj<ATSe
catch(Exception e){e.printStackTrace ();} gA.G:1v
} +z9;BPw%
} g fO.Ky6
<QszmE
(*hA0&n
//打印回应的头信息 g]d@X_ &D
public void logResponseHead(HttpURLConnection con) 6,oi(RAf
{ kQ4%J,7e4
for(int i=1;;i++) 5oORwOP
{ .8wR;^
String header=con.getHeaderFieldKey(i); }*?e w
if(header!=null) N%>/ e'(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (o e;pa
Utility.log(header+" : "+con.getHeaderField(header)); Iye
else ?(ks=rRK
break; 5"@<7/2qI
} g#Yqw
} `uGX/yQ#=
Tm`QZh3
I80.|KIv
public void splitterStop() qjTz]'^BpM
{ '+-R 7#
bStop = true; dJCu`34Y'|
} t}TtWI
rWa7"<`p
ts)0+x
} t6js@Ih
MR8-xO'w
,g^Bu{?
/* S _#UEf
**FileAccess.java ;'cv?3Y
*//文件访问(定位，写) ^\_`0%`>
package NetFox; 1!=$3]l0Lj
import java.io.*; rro,AS}
6G1Z"9<2*
0MPsF{Xw[
public class FileAccessI implements Serializable{ r+ vtKb
in B}ydk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5t0i/&zX
RandomAccessFile oSavedFile; <2,@rYe/
long nPos; ]4hXK!^Uu
J'2R-CI,
VX;u54hS
public FileAccessI() throws IOException )Cx8?\/c=x
{ kqHh@]Z0'
this("",0); RV&2y=eb
} m<OxO\Mpf
l;?.YtMg
$\a;?>WA"
public FileAccessI(String sName,long nPos) throws IOException :G}tvFcOAF
{ t,MK#Ko
oSavedFile = new RandomAccessFile(sName,"rw"); a>s v
this.nPos = nPos; }rGDM
oSavedFile.seek(nPos); u1nv'\*
} b6NttY!3
f+/^1~^
BNzL+"W
public synchronized int write(byte[] b,int nStart,int nLen) 6"%[s@C
{ '^P Ud`
int n = -1; R]ppA=1*_l
try{ RRq*CLj
oSavedFile.write(b,nStart,nLen); E$Ge# M@dM
n = nLen; /=Xen mmS
} iUl{_vb
catch(IOException e) # &M
{ Jl5<9x
e.printStackTrace (); rJNf&x%6
} hefV0)4K
J-X5n 3I&
A.<X78!^
return n; q F}5mUcZ4
} _&BnET
([$F5 q1TR
\,(tP:o
} u1<xt1K
i%\nJs*
9jvg[H
/* qo}kwwWN;
**SiteInfoBean.java <v{jJ7w
*/ Jl^oDW
package NetFox; 8#oF7eE
V-X n&s
Pu*st=KGB
public class SiteInfoBean { T!;<Fy"p
}1$8)zH
Ex*g>~e
private String sSiteURL; //Site's URL c85B-/
private String sFilePath; //Saved File's Path ]|732Z
private String sFileName; //Saved File's Name _abVX#5<
private int nSplitter; //Count of Splited Downloading File fSun{?{
|d:URuG~:I
/>n0&~k[h
public SiteInfoBean() DO%YOv
{//nSplitter的缺省值为5 4&&j7$aV
//default value of nSplitter is 5 NgH%
this("","","",5); Um9=<*p
} -(1e!5_-@
$~`(!pa:
m7!l3W2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) uM4,_)L
{ pXQ&2s$
sSiteURL= sURL; t@4vEKw?.X
sFilePath = sPath; n_c0=YH
sFileName = sName; :A 1,3g
this.nSplitter = nSpiltter; Ni0lj:
?2G^6>O`
rre;HJGEL
} 1 9)78kV{
JLG5`{
+SP5+"y@
public String getSSiteURL() !BQ!]u
{ T]i~GkD\
return sSiteURL; {+`ep\.$&
} w]%r]PwU+
Ads^y`b
54 8@._-S
public void setSSiteURL(String value) $MsM$]~
{ s%/0WW0y^
sSiteURL = value; rAQ^:q
} =]Ek12.
w'qV~rN~tc
l_kH^ET
public String getSFilePath() `[ne<F?e
{ v=W%|iZ
return sFilePath; .^v7LF]Q
} G-:DMjvN
OZv&{_b_
[hiOFmMJZ-
public void setSFilePath(String value) ___+5r21\
{ 5 WAsEP
sFilePath = value; f|apk,o_
} )lW<:?k
2OZdj
JUXK}0d%eN
public String getSFileName() Z`:V~8=l
{ }k,Si9O
return sFileName; 3Yr
} "iKK&%W
4mPg; n
>MhkNy
public void setSFileName(String value) ^^%*2^
{ 7*4F-5G/
sFileName = value; p<J/J.E
} %Ajf|Go0/G
I4");T3
BS{">lPmx
public int getNSplitter() aH>.o 1;
{ ).vdKNzw
return nSplitter; ,Wdyg8&.
} lOEbh
xW^<.@Agm
fj"S|]e
public void setNSplitter(int nCount) Cf10 ud
{ |epe;/
nSplitter = nCount; ^y h
} +6TKk~0e^
} #6YNgJNk
BE m%x0y
#ob">R
/* V&f3>#n\
**Utility.java PSy=O\
*/ [PU.lRq
package NetFox; 6Es-{u(,
[}VEDx
]V9\4#I4
public class Utility { 1f~DUku=
c8u&ev.U
SWmdU]
public Utility() !X,=RR`zT
{ ME7JU|@Z
5ax/jd~}
3XA^{&}
} Q"(i
!u=[/>
//线程睡眠 [NuayO3
public static void sleep(int nSecond) Karyipn}
{ IYrO;GQ
try{ gFW1Nm_DJ
Thread.sleep(nSecond); :oZ30}
} 6x.#K9@q4
catch(Exception e) #q=?Zu^Da
{ :|d3BuY
e.printStackTrace (); T{ojla(
} 19lx;^b
} &yP9vp="
|m?0h.O,
//日志 DsP+#PX
public static void log(String sMsg) ]~|zY5i!
{ k3e $0`Q
System.err.println(sMsg); Ddu$49{S:
} _E?(cWC
oinF<-(
~xA'-N/
public static void log(int sMsg) 8S)k]$wf%
{ 0lW}l9}'-
System.err.println(sMsg); T}g;kppC
} PvO>}(=
} v/(< fI^
_w'4f )7
sbG3,'i)
/* d F),
**TestMethod.java "Z,'NL>&
*/ > ^D10Nf*
package NetFox; 4|*_mC
x0 3|L!n
CjD2FnjT
public class TestMethod { xro
TMq\}k-I5
i)eub`uMy
public TestMethod() =0O`VSb
{ ///xx/weblogic60b2_win.exe Wb^YqqE
try{ E5Z,4B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rs<UWk<q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Xd{"+'29
SiteFileFetch fileFetch = new SiteFileFetch(bean); Dd:Qotu
fileFetch.start(); O'_D*?
} BE:GB?XBH
catch(Exception e){e.printStackTrace ();} ;i\i+:=
3'IF?](]U
>/-<,,<\C
} tEZ@v(D
s,lrw~17
qd(`~a
public static void main(String[] args) vJK0>":G
{ Xul<,U~w6
new TestMethod(); }oloMtp$
} 1?Wk qQ
} cO_En`F
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