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)); ?yAp&Ad
} lKVy{X3]*
for(int i=0;i<nEndPos.length-1;i++) nsT]Yxo%M
{ '8%pEl^
nEndPos = nStartPos[i+1]; JA]TO(x
} TtZZjeg+V
nEndPos[nEndPos.length-1] = nFileLength; '5^$v{
} mM`zA%=
} 0[A4k:
\R"}=7
{?2jvv
//启动子线程 4)]w"z0Pc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +f5|qbX/\
for(int i=0;i<nStartPos.length;i++) $? 'JePC
{ Mn)>G36(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @B.;V=8wJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8PN/*Sa
nStartPos,nEndPos,i); |aAu4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :ik$@5wp
fileSplitterFetch.start(); 3HtLD5%Q
} aJ!(c}N~97
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Drn{ucIs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b*;zdGX.A9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8}B*a;d
nEndPos = " + nFileLength); ;N+ v x
// fileSplitterFetch[nPos.length-1].start(); w)Rtt 9
Vki'pAN
JpI(Vcd
//等待子线程结束 1/ZvcdYB
//int count = 0; F'v3caE
//是否结束while循环 C(=$0FIR
boolean breakWhile = false; O?p8Gjf
tYe+7s
' 91-\en0
while(!bStop) '7'*+sgi$
{ D]n"`< Ho
write_nPos(); P4\{be>e
Utility.sleep(500); \hlQu{q.
breakWhile = true; %NyV2W=~X
sl5y1W/]]
9EPE.+ns
for(int i=0;i<nStartPos.length;i++) 0XkLWl|k
{ ]q,5'[=~4h
if(!fileSplitterFetch.bDownOver) %VV\biO]
{ 2s^9q9NS"
breakWhile = false; t:NYsL
break; >AtW
} a&sVcsX
} ^)JUl!5j]C
if(breakWhile) :,<G6"i
break; u~uR:E%'C
|b BA0.yS
#
//count++; ]+U:8*
//if(count>4) )aV\=a |A
// siteStop(); NmH1*w<A
} G}2DZ=&>'
8!R +wy
/~8<;N>,+
System.err.println("文件下载结束！"); d`XC._%^J
} {6y@;Fd
catch(Exception e){e.printStackTrace ();} IInsq
} 9_$i.@L1
+qWrm|O]
(Xak;Xum1
//获得文件长度 Zb \E!>V
public long getFileSize() m L#%H(
{ zL^`r)H
int nFileLength = -1; 8C[W;&Y=
try{ 6~oo.6bA
URL url = new URL(siteInfoBean.getSSiteURL()); mY)Y47iL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =&!L&M<<
httpConnection.setRequestProperty("User-Agent","NetFox"); _,"?R]MO
(plsL
vp[;rDsIJ$
int responseCode=httpConnection.getResponseCode(); We8n20wf<
if(responseCode>=400) a?d)lnk
{ |vGb,&3
processErrorCode(responseCode); O<*l"fw3
return -2; //-2 represent access is error tx+KxOt9Y
} EMTAl;P
%8L>|QOX
6Mh;ld@
String sHeader; Y ,
wU"0@^k]<
}k{h^!fV
for(int i=1;;i++) o94]:$=~
{ Q#h*C ZT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ycD}7
//Utility.log(in.readLine()); z#j)uD
sHeader=httpConnection.getHeaderFieldKey(i); $-=QTX
if(sHeader!=null) QE#Ar8tU
{ *GGiSt
if(sHeader.equals("Content-Length")) mY'c<>6t
{ cn3F3@_"\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rw|;?a0
break; id"-eMwp
} NCXr$ES{
} TV['"'D&i
else 4PcsU HR
break; fOHgz,x=
} 0DZ}8"2
} MS=zG53y
catch(IOException e){e.printStackTrace ();} Y30T>5
catch(Exception e){e.printStackTrace ();} d%EUr9~?
eM) I%
y-1!@|l0:6
Utility.log(nFileLength); ^p}S5,
C&1()U
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return nFileLength; h{5K9$9=
} ^W*T~V*8
1FPt%{s3
C3hQT8~
//保存下载信息（文件指针位置） l_MF9.z&
private void write_nPos() 45qSt2
{ Nr(t5TP^
try{ Rn4Bl8z'>
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2BGS$$pP
output.writeInt(nStartPos.length); jfOqE*frl!
for(int i=0;i<nStartPos.length;i++) PL}c1Ud
{ <aPbKDF~V
// output.writeLong(nPos); N}/|B}
output.writeLong(fileSplitterFetch.nStartPos); RP9jZRDbZ
output.writeLong(fileSplitterFetch.nEndPos); oR1HJ2>Z1
} Z+%w|Sx
output.close(); K!cLEG!G
} ;dR4a@
catch(IOException e){e.printStackTrace ();} li +MnLt
catch(Exception e){e.printStackTrace ();} iL6Yk @
} 3%0ShMFP@
q-lejVS(g
<|kS`y
//读取保存的下载信息（文件指针位置） V:Lq>rs#
private void read_nPos() \$B%TY
{ |RS(QU<QE
try{ p7{%0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L#>^R
int nCount = input.readInt(); |}07tUq
nStartPos = new long[nCount]; !VoAN5#;
nEndPos = new long[nCount]; 5X1z^(
for(int i=0;i<nStartPos.length;i++) v|K'M,E
{ `Jv~.EF%
nStartPos = input.readLong(); K K_
nEndPos = input.readLong(); ^K]`ZQjKC
} +;|" #
input.close(); uA]!y{"}J
} ~5@bWJ
catch(IOException e){e.printStackTrace ();} 0g{`Qd
catch(Exception e){e.printStackTrace ();} Gkr?M^@K
} cmu|d
H-g CY|W
9ZVzIv(
private void processErrorCode(int nErrorCode) xRp;y*
{ PZ[hH(EX
System.err.println("Error Code : " + nErrorCode); ">|G^@|:A
} 5%#V>|@e#
oa;vLX$
gbvMS*KQz
//停止文件下载 g[%^OT#
public void siteStop() DN0`vl{*
{ Wq"5-U;:w
bStop = true; CEXD0+\q
for(int i=0;i<nStartPos.length;i++) "+sl(A3`U
fileSplitterFetch.splitterStop(); :+?w>
,3P@5Ef
d [f,Nu'
} "IuHSjP
} *2^+QKDG
//负责部分文件的抓取 Po*G/RKu4W
**FileSplitterFetch.java qdQQt5Y'm
*/ AQU^7O
package NetFox; PO@b9O
L}hc|(:
BTAt9Z8qK
import java.io.*; l+XTn;cS
import java.net.*; /73ANQ"
jV 982Y
Pu0 <Clh
public class FileSplitterFetch extends Thread { J-U5_>S
K*sav?c
!3;KC"o
String sURL; //File URL W&Xm_T[Q
long nStartPos; //File Snippet Start Position +zL|j/q?
long nEndPos; //File Snippet End Position DOB#PI[/
int nThreadID; //Thread's ID (`)ZR%i
boolean bDownOver = false; //Downing is over ;kfl5
boolean bStop = false; //Stop identical M$$Lsb [
FileAccessI fileAccessI = null; //File Access interface m/bP`-/,
h#~\-j9>
$VNj0i. Pr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U.A:'9K,
{ 6^VPRp
this.sURL = sURL; ~m6b6Aj@6
this.nStartPos = nStart; !4vepa}Y
this.nEndPos = nEnd; 2kkqPBc_
nThreadID = id; `)TuZP_)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]rS:#LK
} vT{+Z\LL=
&\m=|S
FByA4VxB
public void run() <X"_S'O
{ 8Xx4W^*_
while(nStartPos < nEndPos && !bStop) H#:Aby-d}
{ ^|UD&6 dx
=OamN7V=
S.R|Bwj}(Y
try{ wB+X@AA
URL url = new URL(sURL); xRbtiFk9H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l>*L Am5
httpConnection.setRequestProperty("User-Agent","NetFox"); dGG8k&
String sProperty = "bytes="+nStartPos+"-"; SQ la]%
httpConnection.setRequestProperty("RANGE",sProperty); | {Tq/
Utility.log(sProperty); V: n\skM
P^^WViVX
^^T xx
InputStream input = httpConnection.getInputStream(); jT*?Z:U
//logResponseHead(httpConnection); Y6RbRcJw
:6jh*,OHZl
&a!MT^anA~
byte[] b = new byte[1024]; :YCB23368"
int nRead; E RjMe'q4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :$Xvq-#$|
{ S0w:R:q}L
nStartPos += fileAccessI.write(b,0,nRead); g+]o=@
//if(nThreadID == 1) qGdoRrp0Ov
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ST1c`0e
} '0<9+A#
1O2jvt7M
!W/"Z!k
Utility.log("Thread " + nThreadID + " is over!"); V*gh"gZ<
bDownOver = true; a: 2ezxP
//nPos = fileAccessI.write (b,0,nRead); pEq }b+-
} Jd28/X5&
catch(Exception e){e.printStackTrace ();} uc Ph*M
} zALtG<_t
} |f3 :9(p
IG90mpLX
G=PX'dS
//打印回应的头信息 ttA'RJ
public void logResponseHead(HttpURLConnection con) ?T)M z q}
{ s)G?5Gz
for(int i=1;;i++) IL{tm0$r
{ C."\ a_p
String header=con.getHeaderFieldKey(i); +!mEP>
if(header!=null) AP+%T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dWP<,Z>
Utility.log(header+" : "+con.getHeaderField(header)); .l$U:d
else 20/P:;
break; o>HU4O}
} *iVEO
} L&0aS:
=wlPm5
"KgNMNep
public void splitterStop() *tfD^nctO
{ ~\+Bb8+hpJ
bStop = true; JHa\"h
} U(2=fKK;
%+oqAYm+s
?5;N=\GQ
} sGx3O i
aKintb}n
gxmY^"Jy
/* XTRF IY
**FileAccess.java 9.BgsV .
*//文件访问(定位，写) .'NTy R
package NetFox; e~geBlLar
import java.io.*; G5ShheZd
Qna*K7kv
mbns%%GJU
public class FileAccessI implements Serializable{ f)mOeD*u|
_9'hmej
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QH_Ds,oH=
RandomAccessFile oSavedFile; 10xza=a
long nPos; )iid9K<HB
r7FJqd
c Qe3
public FileAccessI() throws IOException ]Y@_2`
{ fL*+[v4
this("",0); 7Ah
} ^7yaMB!
Z5 7.+z<
}rUAYr~VZ
public FileAccessI(String sName,long nPos) throws IOException Tv6y+l
{ _-rC]iQJ55
oSavedFile = new RandomAccessFile(sName,"rw"); hM[3l1o{|
this.nPos = nPos; r&IDTS#
oSavedFile.seek(nPos); nw_s:
} 5~ZzQG
aKE`nA0\B
Z}{]/=h
public synchronized int write(byte[] b,int nStart,int nLen) qHT73_R
{ ;WAa4r>
int n = -1; EM`'=<)V
try{ s6r(\L_Im
oSavedFile.write(b,nStart,nLen); sWB@'P:x
n = nLen; .FV^hrJxI;
} sVGQSJJ5
catch(IOException e) 0 /9 C=v
{ *Mb'y d/|
e.printStackTrace (); @4MQ021(
} 9Ofls9]U
><S(n#EB
Y]5spqG
return n; G:y+yE4
} ,fqM>Q
9gglyoZ%
tCm]1ZgRW
} y0ObcP.MA
z'Z[mrLq
&,=FPlTC=
/* fFYoZ/\
**SiteInfoBean.java 74N3wi5B
*/ Dv L8}dz
package NetFox; "RM\<)IF
FD&^nJ_{
z@w}+fYO
public class SiteInfoBean { #ti%hm
l5~O}`gfh
4=EA3`l
private String sSiteURL; //Site's URL G "!v)o
private String sFilePath; //Saved File's Path $d!Vxm
private String sFileName; //Saved File's Name m(d|TwG{
private int nSplitter; //Count of Splited Downloading File (CgvI*O
wW/q#kc
c8Ud<M .
public SiteInfoBean() Lq1?Y
{//nSplitter的缺省值为5 pPag@L
//default value of nSplitter is 5 uv<_.Jq]
this("","","",5); f8aY6o"i
} Hb::;[bm:
2ZEGE+0
R&&&RI3{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A<"<DDy
{ \v5;t9uBZ
sSiteURL= sURL; &"I csxG
sFilePath = sPath; +4Pes
sFileName = sName; )p1~Jx(\
this.nSplitter = nSpiltter; W3d+t?28
#.[eZ[
EApbaS}Up
} (Nk[ys}%*
J 7G-qF\
OXbShA&1
public String getSSiteURL() u%+k\/Scp.
{ o kA<
return sSiteURL; vJ=Q{_D=\
} FMI1[|:;
noL9@It0
o|xZ?#^h
public void setSSiteURL(String value) FKz5,PeL
{ ;RX u}pd
sSiteURL = value; `]XI Q\ *
} ' h<(
R3l{.{3p2
~6@`;s`[Y
public String getSFilePath() uC#@qpzy
{ q~[sKAh
return sFilePath; Z+J4q9^$
} (.V),NKG
i,a"5DR8
X~c?C-fV
public void setSFilePath(String value) H~nZ=`P9&
{ C!Srv7
sFilePath = value; <Nqbp
} w:QO@
;l0dx$w
:op_J!;
public String getSFileName() _`&l46
{ ]VLseF
return sFileName; O^row1D_
} j]<K%lwp
%kV7 <:y
Yg3nT:K_Y&
public void setSFileName(String value) @x+2b0 b
{ ]2qKc
sFileName = value; C`ky=
} qrw
]4en|Aq
]kTxVe
public int getNSplitter() Wu/#}Bw#
{ A8*zB=C
return nSplitter; -|uoxj>
} R=LiB+p
o!":mJy
60u_,@rV
public void setNSplitter(int nCount) o25rKC=o
{ iI";m0Ny
nSplitter = nCount; .E}lAd.Mn
} ?V^7`3F
} 3yKmuu!
pLtw|S'4
mL48L57Z
/* zZ8*a\
**Utility.java "O4A&PJD
*/ tj[E!
package NetFox; wqF?o
3^+D,)#D^
;x/eb g
public class Utility { ()?83Xj[c
K8_v5
R/ZScOW[
public Utility() ggx_h
{ "U-jZ5o"
3>aEP5
nJ2x;';lA
} ?Z7QD8N
LD}~]
//线程睡眠 Zob/H+]
public static void sleep(int nSecond) *c94'Tcl
{ SscB&{f
try{ Km8aHc]O~
Thread.sleep(nSecond); `Zm6e!dH-
} vyIH<@@p7
catch(Exception e) !B}9gT
{ 73D<wMgZF
e.printStackTrace (); dWvVK("Wj
} -{xk&EB^$5
} y(p_Unm
VWvSt C
//日志 J{1H$[W~}
public static void log(String sMsg) \:WWrY8&
{ 0 Uropam
System.err.println(sMsg); 'j6O2=1
} $s/E}X
kO}&Oi,?
-Lh7!d
public static void log(int sMsg) TJO$r6&
{ tX{yR'Qhu
System.err.println(sMsg); 9Ux(
} 6:7[>|okQ
} 3 !@
lD/9:@q\V
k2U*dn"9U
/* !mmMAsd,
**TestMethod.java ,yYcjs!=o
*/ FPDTw8" B;
package NetFox; aixX/se
lir=0oq<
Rm} ym9
public class TestMethod { >.iF,[.[F<
Wh)D_
2s\ClT
public TestMethod() @%]A,\
{ ///xx/weblogic60b2_win.exe #Vq9 =Q2
try{ Yq+1kA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Lnr9*dm6q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NBYJ'nA%;f
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2?JV "O=
fileFetch.start(); 5X)8Nwbc
} }e?H(nZS7h
catch(Exception e){e.printStackTrace ();} ?h= n5}Y
Ax;[Em?I
6>a6;[
} ,&P 4%N"
z0[XI7KK
3e_tT8
public static void main(String[] args) UerbNz|
{ k?+ 7%A]
new TestMethod(); [n2B6Px
} N~v6K}`}
} uE-(^u
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