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)); Qz"//=hC|H
} U ,!S1EiBs
for(int i=0;i<nEndPos.length-1;i++) @!|h!p;
{ tgHN\@yj
nEndPos = nStartPos[i+1]; $e.Bz`
} a54S,}|
nEndPos[nEndPos.length-1] = nFileLength; na 0Zb
} xk3)#*
} qQ1D}c@
R^]a<g,
P@x@5uC2
//启动子线程 K)}Vr8,V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; # %'%LY=
for(int i=0;i<nStartPos.length;i++) )\kNufP
{ ~#)9Kl7<X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bJkFCI/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rrq7UJ;
nStartPos,nEndPos,i); eLbh1L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a&dP@)
fileSplitterFetch.start(); 6j!a*u:}"
} qk>M~,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |tz{Es<`B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _X@ Q`d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 88 ca
nEndPos = " + nFileLength); t{`-G*^
// fileSplitterFetch[nPos.length-1].start(); BqdGU-Q
9;rZ)QD
;yCtk ~T%
//等待子线程结束 6zi Mf
//int count = 0; Zu>CR_C
//是否结束while循环 XpA|<s
boolean breakWhile = false; &)|f|\yh"
lwo,D}
uKB V`I
while(!bStop) :qV|rih_Q
{ >SS^qjh/
write_nPos(); 7|Iq4@IT
Utility.sleep(500); E.-2 /'i
breakWhile = true; ]BTISaL-R
u'gsIuRJ
Q5IN1 ^=HF
for(int i=0;i<nStartPos.length;i++) QUF1_Sa
{ " LhXR
if(!fileSplitterFetch.bDownOver) 0UGAc]!/RZ
{ 238z'I+$G/
breakWhile = false; VTi;y{
break; m`b:#z
} ie7TO{W
} Ct:c%D(L
if(breakWhile) Tz7R:S.
break; A2Iqn5
g91xUG
ZS@R?
//count++; >feeVk
//if(count>4) 8^R~qpg%
// siteStop(); $N|Spp0
} RLGIST`
%6Y}0>gY
Ie8SPNY-H
System.err.println("文件下载结束！"); EJJ&`,q
} B*^QTJ
catch(Exception e){e.printStackTrace ();} L:jv%;DM
} N]GF>kf:
cCIs~*D
dbF9%I@
//获得文件长度 5j _[z|W2
public long getFileSize() ZJ[p7XP
{ "L9pFz</
int nFileLength = -1; U]ZI_[\'U
try{ 5z" X>!?^
URL url = new URL(siteInfoBean.getSSiteURL()); ^Nysx ~6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s5X51#J#~
httpConnection.setRequestProperty("User-Agent","NetFox"); En0hjXa
ENf(E9O
?:F Jc[J
int responseCode=httpConnection.getResponseCode(); Kn2W{*wD
if(responseCode>=400) _cJ\A0h^
{ Ac/LNqIs
processErrorCode(responseCode); 1z@ ncqe
return -2; //-2 represent access is error 5rJ7CfVq
} 18y'#<X!
|voZ0U
P{,=a]x,mz
String sHeader; W=,]#Z+M;
'ztY>KVj
yPH5/5;,
for(int i=1;;i++) `|:` yl
{ uFOYyrESc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *4l6+#W
//Utility.log(in.readLine()); e C&!yY2g
sHeader=httpConnection.getHeaderFieldKey(i); K=dG-+B~}
if(sHeader!=null) &*~_ "WyU
{ ^n\g,
if(sHeader.equals("Content-Length")) T3-/+4$0v
{ 1NK,:m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mH'om SCz
break; (]5gYi
} WTZuf9:
} |s!n7%|,7
else e^hI[LbNC
break; I3Ad+]v
} Nm3CeU
} \r&(l1R
catch(IOException e){e.printStackTrace ();} CR-2>,*a9
catch(Exception e){e.printStackTrace ();} F5\{`
XZ/cREz^s
^5-SL?E
Utility.log(nFileLength); *bi;mQ
(T",6xBSG
iF"kR]ZL
return nFileLength; FXid=&T@0D
} q]y{ 4"=5
:/;;|lGw
0'R}'
//保存下载信息（文件指针位置） AQ,%5MeqJ
private void write_nPos() w X.]O!^X~
{ L0ZAF2O
try{ &=lhKt
output = new DataOutputStream(new FileOutputStream(tmpFile)); =8DS~J{
output.writeInt(nStartPos.length); N2Cf(
for(int i=0;i<nStartPos.length;i++) !Eb!y`jK
{ +^%0/0e
// output.writeLong(nPos); @$?*UI6y
output.writeLong(fileSplitterFetch.nStartPos); {.r9l
output.writeLong(fileSplitterFetch.nEndPos); H8!lSRq
} 0|(6q=QK
output.close(); Wk]E6yz6
} /? Bu^KX
catch(IOException e){e.printStackTrace ();} uecjR8\e
catch(Exception e){e.printStackTrace ();} Z'c9xvy5
} wd Di5-A4
tj tN<y
Qs_]U
//读取保存的下载信息（文件指针位置） |PLWF[+t8
private void read_nPos() "T6s;'k
{ p%e/>N.P
try{ a,[NcdG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A)kdY!}
int nCount = input.readInt(); g=S|lVQm
nStartPos = new long[nCount]; prVqV-S6TY
nEndPos = new long[nCount]; ;oRgg'k<
for(int i=0;i<nStartPos.length;i++) @Sz7*p
{ ,L8(Vo`-
nStartPos = input.readLong(); Ewo6Q){X
nEndPos = input.readLong(); gq)uv`3
} R78lV-};Q
input.close(); v0+$d\mP4<
} [<#`@Kr
catch(IOException e){e.printStackTrace ();} <rNz&;m}
catch(Exception e){e.printStackTrace ();} OF`:);
} aOW$H:b
0JLQ.%_
+kOXa^K
private void processErrorCode(int nErrorCode) /Fp@j/50
{ +<c(;Ucl?
System.err.println("Error Code : " + nErrorCode); u:\DqdlU`
} {uiL91j.
e41r!od
<*djtO
//停止文件下载 wUmcA~3D
public void siteStop() [S[@ Q[zP@
{ VqdR
bStop = true; +\MGlsMK@.
for(int i=0;i<nStartPos.length;i++) ^+9i~PjL
fileSplitterFetch.splitterStop(); 8' +I8J0l
C0'_bTfB
P? LpI`f
} g<MCvC@
} aX35^K /
//负责部分文件的抓取 Mog!pmc{
**FileSplitterFetch.java Y!_e,]GW
*/ i7xBi:Si
package NetFox; Bet?]4\_
/U"3LX
!Bb^M3iA
import java.io.*; ngH_p>
import java.net.*; H`8}w{ft&
rh6m
_U%2J4T2
public class FileSplitterFetch extends Thread { nnMRp7LQ-
,a} vx"~
f15n ~d
String sURL; //File URL IL<@UWs6
long nStartPos; //File Snippet Start Position bH_zWk
long nEndPos; //File Snippet End Position mbO.Kyfen
int nThreadID; //Thread's ID RMBPm*H
boolean bDownOver = false; //Downing is over K=;oZYNd
boolean bStop = false; //Stop identical 9AZpvQ
FileAccessI fileAccessI = null; //File Access interface oF(|NS^
}&IOBYHVDo
Uj>bWa`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =7<g;u
{ a &tl@y1
this.sURL = sURL; -l q,~`v
this.nStartPos = nStart; 0I[3%Q{
this.nEndPos = nEnd; Lz}mz-N
nThreadID = id; N uq/y=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CYN|
} ~ ^)4*@i6
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_9"%;:t
public void run() N(L?F):fT
{ )zq sn
while(nStartPos < nEndPos && !bStop) " IC0v9
{ /}RW~ax
$rmfE
@#&y
try{ mdukl!_x
URL url = new URL(sURL); 4$jb-Aw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "9yQDS:
httpConnection.setRequestProperty("User-Agent","NetFox"); hIMD2
String sProperty = "bytes="+nStartPos+"-"; i 9wk)
httpConnection.setRequestProperty("RANGE",sProperty); mEDi'!YE"
Utility.log(sProperty); l*<RKY8
m}?(c)ST
Y@[Dy
InputStream input = httpConnection.getInputStream(); hZLwg7X!
//logResponseHead(httpConnection); "A,-/~cBV
F<A[S"
TTzvH;S
byte[] b = new byte[1024]; O{nM yB
int nRead; I]Jz[{~1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D]$X@2A
{ OO`-{HKt
nStartPos += fileAccessI.write(b,0,nRead); haIH `SY
//if(nThreadID == 1) 1A-ess\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R3gg{hQ
} \v[?4[
YVB\9{H?
ld/\`s[i
Utility.log("Thread " + nThreadID + " is over!"); UqaV9
bDownOver = true; 8!u8ZvbFG
//nPos = fileAccessI.write (b,0,nRead); a 9f%p
} }o MY
catch(Exception e){e.printStackTrace ();} Q{+N{/tF
} z\?cazQ
} WEFvJ0]
lq\/E`fc`
b)Dzau
//打印回应的头信息 &Ew{{t;"
public void logResponseHead(HttpURLConnection con) D\i8WU
{ ~V<imF
for(int i=1;;i++) Id;YIycXe
{ e|jmOYWG
String header=con.getHeaderFieldKey(i); V?"SrXN>
if(header!=null) ZF6?N?t}h8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HCTjFW>C
Utility.log(header+" : "+con.getHeaderField(header)); o&b1-=MC2
else 3,RaM^5dV
break; Erd)P
} 1dahVc1W
} 2[R{IV8e
_0(Bx?[h
Pf?y!dK<
public void splitterStop() ^&6'FE
{ \<K@t=/ 6
bStop = true; UN6Du\)]d
} c>nXnN
NRgNW1#
pv #uLo
} j[<}l&
U$5 lh
WGeTL`}dh
/* bI?YNt,
**FileAccess.java 4tv}V:EO
*//文件访问(定位，写) vPA {)l\K
package NetFox; c3$h-M(jVJ
import java.io.*; =UW! 7OzC
t^zmvPDK
x O~t
public class FileAccessI implements Serializable{ 4#^?-6
\E3evU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !9knFt43
RandomAccessFile oSavedFile; k{q4Zz[
long nPos; <i(<|/$
` kG}NJf
J` J^C
public FileAccessI() throws IOException kt*""&R
{ LCMCpEtY*K
this("",0); 1IRlFC
} aOH$}QnS
Eu^?e
{Bb:S"7NX
public FileAccessI(String sName,long nPos) throws IOException vhQIkB8
{ HX77XTy
oSavedFile = new RandomAccessFile(sName,"rw"); !K~:crUV|S
this.nPos = nPos; -0/5!
oSavedFile.seek(nPos); <cn{S`
} sw'?&:<"Ow
0[qU k(=}[
s;'jn_,0
public synchronized int write(byte[] b,int nStart,int nLen) |_^A$Hv
{ I*Q^$YnM
int n = -1; N5%zbfKM
try{ 9j;L-
oSavedFile.write(b,nStart,nLen); "X }@VT=
n = nLen; l"#}g%E
} L-T3{I,3
catch(IOException e) mu?6Phj
{ boJ
e.printStackTrace (); 5uU.K3G7
} Ikn)XZU^
[?vn>
|%@.@c
return n; D/ SM/
} gfPht 5
-!k$ Z
g{}{gBplnl
} DKG%z~R*
?{OB+f}Mo
A@kp`-
/* .%pbKi `
**SiteInfoBean.java $YX\&%N
*/ 'F- wC!
package NetFox; 8RfFP\AP
Vg0$5@
zIyMq3
public class SiteInfoBean { >J]^Rgn>
^MUSq(
;;2Yfn'`9
private String sSiteURL; //Site's URL RvQl{aL
private String sFilePath; //Saved File's Path 2$g3ABfV
private String sFileName; //Saved File's Name i8\&J.
private int nSplitter; //Count of Splited Downloading File KfO$bmwmx
7eh<>X!TX
?5A!/`E&%
public SiteInfoBean() ,&1DKx
{//nSplitter的缺省值为5 d&dp#)._8
//default value of nSplitter is 5 &3Q!'pJJ
this("","","",5); Z*}5M4
} rl0sN5n
8%dE$smH
){PL6|5x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BixKK$Lo
{ &3SQVOW ~T
sSiteURL= sURL; 8e`'Ox_5a
sFilePath = sPath; 2&f]v`|M|
sFileName = sName; l.#iMi(@p~
this.nSplitter = nSpiltter; *<PQp
$R'
cZ@z]LY.g
} Q!%4Iq%jr
"t-u=aDl-.
b#:Pl`n6u
public String getSSiteURL() }E\ b_.
{ p@H3NX
return sSiteURL; vakAl;
} $\0%"S
PfaBzi9?f
:Kl~hzVSOa
public void setSSiteURL(String value) JP2zom
{ |6%B2I&c
sSiteURL = value; 'Y ZYRFWXM
} FY^[?lj
dU7+rc2,CU
h@5mVTb}i
public String getSFilePath() TsPx"+>7`
{ y&HfF~
return sFilePath; f__r" N
} .#M'
#bqc}h9
T+OQa+E@P
public void setSFilePath(String value) ^ di[J^
{ *?zyF@K{%
sFilePath = value; CQfrAk4mu
} >'eOzMBn
m3]|I(]`Xe
po_||NIY
public String getSFileName() 4%O*2JAw
{ lp5`Kw\
return sFileName; jh.W$.Oq
} juuBLv
JDVMq=ui
"H>L!v
public void setSFileName(String value) ;J pdnV
{ BDY@&vF
sFileName = value; }x4,a6^
} ,J?Hdy:R
~uRG~,{rH
<by}/lF0
public int getNSplitter() {O*<1v9<
{ *&B1(&{:V
return nSplitter; tYyva
} 2X2,(D!
GP ;c$pC
\sFdp!M}2
public void setNSplitter(int nCount) N1WP
{ 8Dpf{9Y-E
nSplitter = nCount; ABEC{3fWpu
} zcItZP
} W5?F?Dp!v
w[PWJ! <
HbF.doXK
/* MrjET!`.jC
**Utility.java 9z5K -s
*/ $DW3H1iW
package NetFox; fXMVl\ <
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/_E:sI9(
public class Utility { $enh>!mU
u4B,|_MK
*!UY;InanX
public Utility() 5=Mm=HyI2
{ WMBntB
<Fb3\T L
70&v`"
} 13Ga #
eN{[T PPCq
//线程睡眠 yyh L]Uq"=
public static void sleep(int nSecond) 8%JxXtWW`
{ (5{|']G
try{ o#E 3{zM
Thread.sleep(nSecond); mnL \c'
} 1Nx.aji
catch(Exception e) vTjgW?9
{ R|H9AM ~E
e.printStackTrace (); "!XeK|Wi
} m}0US;c#f
} OlhfBu)~
PRl\W:_t
//日志 +O3zeL
public static void log(String sMsg) =25qY"Mf
{ ?RvXO'ml
System.err.println(sMsg); VE^NSkOa&
} _:0<]<x?
}5bh,'
)7=B]{B_
public static void log(int sMsg) \(.&E`r
{ uOc>~ITPS
System.err.println(sMsg); MQE=8\
} ,T"pUeVJ
} ]P$8# HiX
'Z'X`_
oT&JQ,i[2Q
/* Y32F{ z
**TestMethod.java ]>/YU*\
*/ !`\W8JT+
package NetFox; i9k7rEW^
(p`'Okw
VP\HPSp
public class TestMethod { rB?u.jn0T
E!Hq%L!/
xq=+M!V
public TestMethod() F/ 2@%,2n
{ ///xx/weblogic60b2_win.exe hSaS2RLF
try{ -'JTVfm.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I!jSAc{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [6 wI22
SiteFileFetch fileFetch = new SiteFileFetch(bean); [V{JuG;s
fileFetch.start(); KoiU\r
} 64s+ 0}
catch(Exception e){e.printStackTrace ();} "%urT/Fv&
%H>vMR-,~
|`s}PcV
} 66D<Up'K
wc)[r~On(5
*x`z5_yfO
public static void main(String[] args) FFbMG:>:
{ <.$<d
new TestMethod(); dJ?VN!B0
} Y+iC/pd
} b@^M|h.Va
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