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)); \= v.$u"c
} Hl,{4%]
for(int i=0;i<nEndPos.length-1;i++) iqvLu{
{ S[1<Qrv]
nEndPos = nStartPos[i+1]; ~.aR=m\#
} 4T31<wk
nEndPos[nEndPos.length-1] = nFileLength; nd]SI;<
} (da`aRVDp
} o5bp~.m<
1ZI1+TDH
M@R"-$Z
//启动子线程 S3\NB3@qC&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eCYPd-d
for(int i=0;i<nStartPos.length;i++) 5E\.YqdV
{ "iA0hA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N[po)}hp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k5I;Y:~`
nStartPos,nEndPos,i); d.FU))lmD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $AZYY\1
fileSplitterFetch.start(); g}NO$?ndg
} Q,[G?vbj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "E(i<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SLKplLO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Wd:pqhLh
nEndPos = " + nFileLength); j{%;n40$
// fileSplitterFetch[nPos.length-1].start(); %rylmioW>
m+0yf(w
dymq Z<
//等待子线程结束 #RBrii-,
//int count = 0; v>_@D@pr
//是否结束while循环 }T@=I&g;
boolean breakWhile = false; &eHRn_st5b
HU'Mi8xxy
M76p=*
while(!bStop) K6kz{R%`
{ inWLIXC,
write_nPos(); --WQr]U/
Utility.sleep(500); L}`/v]E"eU
breakWhile = true; =]%JTGdp(
sp,-JZD
M]s\F(*ib
for(int i=0;i<nStartPos.length;i++) L[x`i'0B
{ <E2 IU~e
if(!fileSplitterFetch.bDownOver) qYC&0`:H
{ #7]Jz.S
breakWhile = false; ,U~A=bsa
break; h3o'T=`Sm
} +>"s)R43
} 1,-C*T}nR
if(breakWhile) XwY,xg&o
break; jr=9.=jI8k
>v]^nJl
iH8we,s'
//count++; wXIRn?z
//if(count>4) ubwM*P
// siteStop(); jH< #)R
} GC')50T J
2? qC8eC
$aV62uNf
System.err.println("文件下载结束！"); =Hg!@5]H
} mtmC,jnD
catch(Exception e){e.printStackTrace ();} <tD,Uu{P
} qX,q*hr-
3vY-;&
#EH=tJgO|J
//获得文件长度 BU:;;iV8
public long getFileSize() C?\(?%B
{ 32wtN8kx
int nFileLength = -1; #AJW-+1g.=
try{ =I# pXL
URL url = new URL(siteInfoBean.getSSiteURL()); x3q^}sj%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y bhFDx
httpConnection.setRequestProperty("User-Agent","NetFox"); 731Lz*IFg
K!6T8^JH
f/)Y {kS6
int responseCode=httpConnection.getResponseCode(); ui%#f1Iq
if(responseCode>=400) y98FEG#S}
{ (VeK7cU
processErrorCode(responseCode); ^&qK\m_A
return -2; //-2 represent access is error EtcT:k?y
} ciblj?"Wi
\u,CixV=
Db|f"3rq?
String sHeader; 8 0tA5AP
sY;h~a0n
riIubX#
for(int i=1;;i++) 0~U#DTx0
{ Ui'v' $
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t]h_w7!U
//Utility.log(in.readLine()); #Zdh<.
sHeader=httpConnection.getHeaderFieldKey(i); o%_-u +
if(sHeader!=null) mkSu $c
{ A(2 0+
if(sHeader.equals("Content-Length")) r8EJ@pOF2w
{ ZFtx&vrP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T8S&9BM7
break; 1aAOT6h
} ~O}r<PQ
} [+\He/M6
else 2j-l<!s
break; A%^?z.
} Wd'}YbC
} vFUp$[
catch(IOException e){e.printStackTrace ();} jj{:=lZB
catch(Exception e){e.printStackTrace ();} p/{%%30ke
In?rQiD9
Qw0k-t0=4
Utility.log(nFileLength); Cff6EE
*y4DK6OFe
xm{?h,U,
return nFileLength; P.Ntjz/B
} 9K$ x2U
zqA>eDx
sl$6Zv-l%0
//保存下载信息（文件指针位置） ^(q .f=I!a
private void write_nPos() R>bg3j
{ mnA_$W3~I
try{ Bl+\|[yd
output = new DataOutputStream(new FileOutputStream(tmpFile)); uuM1_nD[
output.writeInt(nStartPos.length); y3efie {J
for(int i=0;i<nStartPos.length;i++) OLx;j+p
{ #N][-i
// output.writeLong(nPos); #6M |T+=
output.writeLong(fileSplitterFetch.nStartPos); Fg`<uW]TFZ
output.writeLong(fileSplitterFetch.nEndPos); p*<Jg l
} _WS8I>
output.close(); -53c0g@X
} =X'[r
catch(IOException e){e.printStackTrace ();} ~i1 jh:,
catch(Exception e){e.printStackTrace ();} #ft9ms#N
} Qb {[xmc
G8}owszT
- +a,Ej
//读取保存的下载信息（文件指针位置） Zq4%O7%
private void read_nPos() AWcbbj6Nd
{ #x.v)S
try{ f/dJRcDl<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tgpu9V6
int nCount = input.readInt(); f>Rux1Je4
nStartPos = new long[nCount]; x_3B) &9
nEndPos = new long[nCount]; Ry+?#P+
for(int i=0;i<nStartPos.length;i++) @x1cV_s[
{ ;L$-_Z
nStartPos = input.readLong(); OG{*:1EP
nEndPos = input.readLong(); =Htt'""DN
} p-j6H
input.close(); +&\. ]Pp
} N_92,xI#
catch(IOException e){e.printStackTrace ();} ,~3rY,y-
catch(Exception e){e.printStackTrace ();} ^P,Pj z
} "EpH02{i
,x\qYz+7|
%vO(.A+
private void processErrorCode(int nErrorCode) *$O5.`]
{ Lx_Jw\YO
System.err.println("Error Code : " + nErrorCode); qb;b.P?~D$
} g{Av =66Z
ASdW!4.p
=R:O`qdC4e
//停止文件下载 >,Y+1
public void siteStop() !n;3jAl&$
{ fln[Q2zl
bStop = true; w7`pbcY,
for(int i=0;i<nStartPos.length;i++) U`[viH>K
fileSplitterFetch.splitterStop(); _p"u~j~%-
8pEA3py
`Hw][qy#
} [.&JQ
} r],%:imGr
//负责部分文件的抓取 g(zeOS]q}
**FileSplitterFetch.java yf*'=q
*/ RR=WD-l
package NetFox; -\p&18K#
Fah6 &a
]Sj;\Iz
import java.io.*; NU_^*@k
import java.net.*; Zb_A(mnzh
2c]751
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public class FileSplitterFetch extends Thread { mxEe -q
.<vXj QE
>-V632(/{o
String sURL; //File URL z 8M\(<
long nStartPos; //File Snippet Start Position n><ad*|MX
long nEndPos; //File Snippet End Position 9Tr ceL;
int nThreadID; //Thread's ID Ytc[ kp
boolean bDownOver = false; //Downing is over /*;a6S8q
boolean bStop = false; //Stop identical '__>M>[
FileAccessI fileAccessI = null; //File Access interface 4IW fp&Q!
--diG$x.
<}RD]Sc$1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HY_>sD
{ CF3x\6.q}
this.sURL = sURL; \A^8KVE!
this.nStartPos = nStart; (Zx--2lc
this.nEndPos = nEnd; q~#>MB}".
nThreadID = id; q{V e%8$"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /t`|3Mw
} ..Dm@m}
/&\V6=jA1
8D>5(Dg-
public void run() iz^a Qx/
{ !\|
while(nStartPos < nEndPos && !bStop) 9{3_2CIL
{ [f\Jcjc
(gYW iz
PZru:.Mh
try{ ogSDV
URL url = new URL(sURL); =p5]r:9W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _"x%s
httpConnection.setRequestProperty("User-Agent","NetFox"); 1.u^shc&|
String sProperty = "bytes="+nStartPos+"-"; UUDbOxD^w
httpConnection.setRequestProperty("RANGE",sProperty); f6J]=9jU
Utility.log(sProperty); \^0>h`[
"c} en[
4S*ifl
InputStream input = httpConnection.getInputStream(); <BT18u\
//logResponseHead(httpConnection); Kn3Xn`P?
R`$Y]@i&B
CAx$A[f<
byte[] b = new byte[1024]; $aEv*{$y
int nRead; I*j~5fsS'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _QHk&-Lp
{ [>>_%T\I
nStartPos += fileAccessI.write(b,0,nRead); oQpGa>6U&
//if(nThreadID == 1) @C^x&Sjm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e}-fGtFx
} 66-\}8f8a
y$nI?:d
,<!*@xy7v
Utility.log("Thread " + nThreadID + " is over!"); `%~}p7Zu
bDownOver = true; z9&j
//nPos = fileAccessI.write (b,0,nRead); 3]'ab-,Vp
} ]%-U~avph
catch(Exception e){e.printStackTrace ();} 4Th?q{X
} pRh9+1EM;
} o"0~
/Z]nV2$n)V
I9L3Y@(f6m
//打印回应的头信息 QKEtV
public void logResponseHead(HttpURLConnection con) T^MY w
{ wbOYtN Y@
for(int i=1;;i++) !wUznyYwt
{ IhK SwT
String header=con.getHeaderFieldKey(i); h}'Hst
if(header!=null) Q=%W-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $bKXP(
Utility.log(header+" : "+con.getHeaderField(header)); E@otV6Wk[@
else $?!]?{K
break; ?7)v:$(G}
} 4~A$u^scn
} qLX<[UL
.3UJ*^(?
I74Rw*fB
public void splitterStop() h{_\okC>
{ 2o9B >f&g
bStop = true; CG@Fn\J
} 49>b]f,Vc
4a&8G
XXX y*/P
} ld#x'/
{[:C_Up)f
raOuD3
/* f?^-JZ
**FileAccess.java OO?N)IB@
*//文件访问(定位，写) PfU\.[l$
package NetFox; #>KiX84
import java.io.*; nu+^D$ait
3rFku"zT$
@=AQr4&
public class FileAccessI implements Serializable{ Vb#a ,t
At<MY`ka
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'OTZ&;7{
RandomAccessFile oSavedFile; ^Os }sJ*5S
long nPos; V,VL?J\
?(R#
&qPezyt
public FileAccessI() throws IOException A0@,^|]
{ FXY>o>K%h
this("",0); A{-S )Z3}
} fnr8{sr.2Z
OESKLjFt
yU/?4/G!
public FileAccessI(String sName,long nPos) throws IOException 9 4H')(
{ t\QLj&h}E
oSavedFile = new RandomAccessFile(sName,"rw"); $X-PjQb1Bb
this.nPos = nPos; &R.5t/x_
oSavedFile.seek(nPos); ORP<?SG55u
} G na%|tUz|
W;R6+@I[
XNx$^I=
public synchronized int write(byte[] b,int nStart,int nLen) WvF{`N
{ Q\IViM
int n = -1; ;*zLf 9i
try{ 5*A5Y E-
oSavedFile.write(b,nStart,nLen); ^1c7\"{
n = nLen; y2?9pVLa\y
} 1k:yU(
catch(IOException e) l,Y5VGiH#
{ Wk3-J&QbS
e.printStackTrace (); r{d@74
} f^QC4hf0
x.t&NP^V)
3)CIqN
return n; aynaV
} E<! L^A M`
=AzkE]
05HCr"k
} cs\=8_5
t 3N}):
t@#5 G* _Q
/* (i(E~^O
**SiteInfoBean.java n7~3~i`D;
*/ vvY?8/
package NetFox; 5CcX'*P
_hl| 3 eW5
r90tXx
public class SiteInfoBean { `EMGrw_
\fC;b"j
bG"FN/vg
private String sSiteURL; //Site's URL u=s,bt,"5
private String sFilePath; //Saved File's Path a""9%./B
private String sFileName; //Saved File's Name t1 9f%d
private int nSplitter; //Count of Splited Downloading File e~)4v
D5Sbs(
60%fva
public SiteInfoBean() wTR?8$
{//nSplitter的缺省值为5 I*o6Bn |D
//default value of nSplitter is 5 BB3a8
this("","","",5); Rvf{u8W
} Z)~?foe'
OOIp)=4
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .WN&]yr,
{ |zfFB7}v
sSiteURL= sURL; Mi(6HMA.SF
sFilePath = sPath; 7=X6_AD
sFileName = sName; WwnBe"7M
this.nSplitter = nSpiltter; !.V_?aYi8
O"TVxP:
S=V
} Ufi#y<dP
@,Dnl v|?
v+sF0 j\P
public String getSSiteURL() *wmkcifF;
{ nIBeZof
return sSiteURL; qA!4\v={
} {df;R|8l
xo @|;Z>&F
/{8Y,pZbu
public void setSSiteURL(String value) KgD$P(J:[
{ H*0g*(
sSiteURL = value; +RpCh!KP
} zCA8}](C^
txnH~;(
t'W6Fmwkx
public String getSFilePath() cC$YD]XdIA
{ 8R\6hYJ%F
return sFilePath; [D+PDR
} GFbn>dY
V#b*:E.cA
<x;g9Z>(
public void setSFilePath(String value) jM6$R1HX
{ F+R1}5-3cl
sFilePath = value; ZT/f
} Z \ @9*
zSsBbu:
LR#.xFQ+
public String getSFileName() =M@)qy
{ im:[ViR {
return sFileName; 9%ct
} m^ar:mK@
Xu_1r8-|=b
r:0RvWif
public void setSFileName(String value) tZ@&di:-F
{ hTby:$aCg
sFileName = value; J'=s25OWU
} c; .y
\?e2qu/ C
3bC-B!{;g
public int getNSplitter() d@JavcR
{ gV':Xe
return nSplitter; fWfhs}_
} k8}'@w
$`0^E#Nl
K]>4*)A:
public void setNSplitter(int nCount) u\xrC\Ka
{ G5 )"%G.
nSplitter = nCount; |yOIC,5[JW
} Fgwe`[
} 9_&]7ABV
$E:z*~?
^Vh^Z)gGi
/* 't(#HBU
**Utility.java *n@rPr-
*/ E:\#Ur2
package NetFox; SU7,uxF
xK1w->[
BgCEv"G5
public class Utility { ,T 3M
V+0pvgS[
sKiy1Ww
public Utility() 1#>uqUxah
{ d--6<_q
u,72Mm>
r`)'Kd
} +\PLUOk
n^G[N-\3
//线程睡眠 +W[{UC4b
public static void sleep(int nSecond) 0_^3 |n
{ <7ag=IgDy
try{ NgxJz ]b
Thread.sleep(nSecond); ) AGE"M3X
} HPO:aGU
catch(Exception e) tg/!=g
{ Uul5h8F
e.printStackTrace (); Y3)*MqZlF
} Lq@uwiq!
} Dg ~k"Ice
65+2+p
//日志 T`I4_x
public static void log(String sMsg) brCL"g|}
{ nM8'="$
System.err.println(sMsg); 6(A"5B=\
} 0Y~5|OXJ
1Sns$t%b
q8e]{sT'!
public static void log(int sMsg) [zrFW g6N
{ a*_" nI&lr
System.err.println(sMsg); dt<P6pK-
} &)!N5Veb
} `v/p4/
E%Ysyk
%|2x7@&s
/* e<u~v0rDl
**TestMethod.java Fb{HiU9<!
*/ 1[RI 07g7*
package NetFox; VF<VyWFC0`
R\6dvd
#N97
public class TestMethod { _w5c-\-PUM
;t.)A3 PL
te>Op 1R
public TestMethod() x+Ly,9nc$
{ ///xx/weblogic60b2_win.exe RtaMrG=D
try{ 1yc$b+TH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3Z}m5f`t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mI;\ UOh'
SiteFileFetch fileFetch = new SiteFileFetch(bean); NeewV=[%
fileFetch.start(); (I1^nrDP.
} H,!yG5yF
catch(Exception e){e.printStackTrace ();} K1-3!G
sa"!ckh
Ob|tA
} xCu\jc)2
~!Rf5QA85
[XA:pj;rg'
public static void main(String[] args) vcOw`oS
{ /5f=a
new TestMethod(); l>7?B2^<E
} P$/Y9o
} \&v)#w
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