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)); P}~nL
} f >$V:e([
for(int i=0;i<nEndPos.length-1;i++) EPiZe-
{ jt`\n1q)
nEndPos = nStartPos[i+1]; _%]x-yH!@
} hCpcX"wND
nEndPos[nEndPos.length-1] = nFileLength; 05ovz
} T*{nf
} ZwOX ,D
c-oIP~,
uW0Dm#
//启动子线程 d}^G790
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W|CZA
for(int i=0;i<nStartPos.length;i++) W,fXHYst
{ *bSxobn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yvIzgwN%s!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]114\JE
nStartPos,nEndPos,i); !g7lJ\B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1LVO0lT
fileSplitterFetch.start(); zff<#yK1
} QWI)Y:<K/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vf;&0j&`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bae\EaS ?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \e9rXh%
nEndPos = " + nFileLength); svvl`|n%
// fileSplitterFetch[nPos.length-1].start(); M2!2J
i`^[_
RdqB^>X
//等待子线程结束 qV5lv-p
//int count = 0; YhQ%S}
//是否结束while循环 N;S1s0FN
boolean breakWhile = false; @@V{W)rl
qO{Yr$V%
N4)ZPLV
while(!bStop) <7 xX/Z}M
{ "[dfb#0z`
write_nPos(); Vrn+"2pdJ
Utility.sleep(500); :5[1Iepdn
breakWhile = true; K_ Odu^
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{Jc.49
for(int i=0;i<nStartPos.length;i++) Om_-#S
{ CB^.N>'
if(!fileSplitterFetch.bDownOver) 2 9#jKh
{ Q.,2G7[ <
breakWhile = false; 8Z!Mad
break; ):lH
} %%sJ+)
} Z=dM7Lj*
if(breakWhile) 'E"W;#%
break; 5m2f\^U
(vFO'jtcB-
Hu$y8_Udw
//count++; bm poptfL
//if(count>4) X]}:WGFM
// siteStop(); &embAqW:
} .'PS L
6d(D>a
T^icoX=c4
System.err.println("文件下载结束！"); nc^DFP
} fS$;~@p
catch(Exception e){e.printStackTrace ();} :i>If:>g
} HCw,bRxm
NXX/JJ+w
l5/gM[0_7
//获得文件长度 B \LmE+a>
public long getFileSize() ]d~2WX Y
{ 89x;~D1
int nFileLength = -1; .: k6Kg
try{ ;EQ7kuJQ?
URL url = new URL(siteInfoBean.getSSiteURL()); g'AxJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =O3)tm;
httpConnection.setRequestProperty("User-Agent","NetFox"); yoH,4,!G
[@_W-rA
{fJCj152.
int responseCode=httpConnection.getResponseCode(); d7S?"JpV
if(responseCode>=400) qTSe_Re
{ Lp)P7Yt-
processErrorCode(responseCode); s:3b.*t<
return -2; //-2 represent access is error >f'aW
} ejc>
x~Dj2F]
JwQ/A[b
String sHeader; IGOEqUw*
82iFk`)T
=!\Y;rk
for(int i=1;;i++) p\R&vof*
{ Xe&p.v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qKrxln/T
//Utility.log(in.readLine()); waU2C2!w
sHeader=httpConnection.getHeaderFieldKey(i); h[mJ=LIrg
if(sHeader!=null) wjfq"7Q
{ 6qSsr]
if(sHeader.equals("Content-Length")) {1gT{2/~@
{ ?,i}Qr [Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >Ptu-*
break; qOy0QZ#0
} [ ebk u_
} \CX6~
else adPd}rt;
break; _F5*\tQ
} ( k,?)
} bct8~dY
catch(IOException e){e.printStackTrace ();} ,m8mh)K?0>
catch(Exception e){e.printStackTrace ();} 3m| C8:
THARr#1b};
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Utility.log(nFileLength); mVFo2^%v
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u 7:Iv
return nFileLength; A"z9t#dv@
} *E]:VZl
+D2I~hC0'
9F[_xe@
//保存下载信息（文件指针位置） _M+7)[xj=
private void write_nPos() wh)F&@6 R!
{ 0*_E'0L8e
try{ Ra"hdxH
output = new DataOutputStream(new FileOutputStream(tmpFile)); {A'*3(8
output.writeInt(nStartPos.length); >7PNl\=gG
for(int i=0;i<nStartPos.length;i++) K?Sy?Kz
{ Au6Y]
// output.writeLong(nPos); .)SR3?
output.writeLong(fileSplitterFetch.nStartPos); f!#+cM
output.writeLong(fileSplitterFetch.nEndPos); =t`cHs29
} }*C*!?pcd
output.close(); !*f$*,=^
} [2Zl '+
catch(IOException e){e.printStackTrace ();} C T\@>!'f
catch(Exception e){e.printStackTrace ();} 7WwE] ^M
} b;%t*?t
?(n v_O
Xdwpn+7s
//读取保存的下载信息（文件指针位置） }=}wLm#&1
private void read_nPos() |-;VnC&UY
{ JHXkQz[Jb
try{ L^r & .N\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;s;3cC!
int nCount = input.readInt(); NJ]3qH
nStartPos = new long[nCount]; a9UXg<4
nEndPos = new long[nCount]; kIX1u<M~
for(int i=0;i<nStartPos.length;i++) Kk*8
{ l*6Zh"o:
nStartPos = input.readLong(); 8NiR3*1
nEndPos = input.readLong(); uovv">Uw
} N/ f7"~+`
input.close(); 6]4#8tR1_
} Nk<^ Qv
catch(IOException e){e.printStackTrace ();} 4"_`Mu_%
catch(Exception e){e.printStackTrace ();} {0j_.XZ
} [F'|KcE3
!=A;?Kdq
IrMB=pWo
private void processErrorCode(int nErrorCode) +<j7^AEG
{ 8XG';K_
System.err.println("Error Code : " + nErrorCode); s*s~yH6
} Q@7d:v
Bp3E)l
zh|9\lf
//停止文件下载 JXM]tV
public void siteStop() hHGuD2%
{ DY9]$h*y
bStop = true; IvT><8<G
for(int i=0;i<nStartPos.length;i++) t&:L?K)j
fileSplitterFetch.splitterStop(); [:FiA?O]
xM(H4.<
g;v;xlY`N
} ?3p7MjvZ
} ;AE-=/<
//负责部分文件的抓取 p[(I5p:L
**FileSplitterFetch.java A4'5cR9T!
*/ ,zltNbu\.(
package NetFox; ! 5NuFLOf
8AX_y3$
:nQlS
import java.io.*; IO:*F0
import java.net.*; h%krA<G9
o6d x\
t*=[RS*
public class FileSplitterFetch extends Thread { r!+{In+Z
W*t] d
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String sURL; //File URL @phVfP"M
long nStartPos; //File Snippet Start Position \ l#eW x
long nEndPos; //File Snippet End Position KWZhCS?[(
int nThreadID; //Thread's ID 3iIy_nWC
boolean bDownOver = false; //Downing is over qh:Bc$S
boolean bStop = false; //Stop identical aPVzOBp
FileAccessI fileAccessI = null; //File Access interface 3f] ;y<Km
QYboX~g~p
USEb} M`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j/z=<jA
{ >m>F {v
this.sURL = sURL; \gk.[={^P
this.nStartPos = nStart; -}9^$}PR
this.nEndPos = nEnd; D]]wJQU2
nThreadID = id; )63 $,y-;$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dPwyiV0
} L%T(H<G
.VCY|KZ
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public void run() !g9k9 l
{ V}Y*Yv
while(nStartPos < nEndPos && !bStop) M'PZ{6;
{ njF$1? )sq
Lr:Qc#2
0RT8N=B83
try{ du66a+@t
URL url = new URL(sURL); Zgo~"G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IHni1
httpConnection.setRequestProperty("User-Agent","NetFox"); A~2)ZdAN
String sProperty = "bytes="+nStartPos+"-"; ~w+I2oS$
httpConnection.setRequestProperty("RANGE",sProperty); G aV&y
Utility.log(sProperty); <qwf"Ey
N2v/<
|QDoi[ *
InputStream input = httpConnection.getInputStream(); IT1YF.i
//logResponseHead(httpConnection); }/F$73Xd
AJbCC
TI4Hu,rc
byte[] b = new byte[1024]; YV<y-,Io
int nRead; |oi+|r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #wI}93E
{ d+ jX49Vt
nStartPos += fileAccessI.write(b,0,nRead); _x!idf
//if(nThreadID == 1) a%T`c/C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N/bOl~!y
} X.eOw>.
3m1(l?fp
q(?+01
Utility.log("Thread " + nThreadID + " is over!"); `RL Wr,h
bDownOver = true; uiVNz8H
//nPos = fileAccessI.write (b,0,nRead); L"qJZU
} V4:/LNq_]
catch(Exception e){e.printStackTrace ();} Io1j%T#ZT
} eQuu\/z*H
} 5#,H&ui\
P:"R;YCvE
YYv0cV{E
//打印回应的头信息 apo)cR
public void logResponseHead(HttpURLConnection con) An{>39{
{ /MGapmqV9
for(int i=1;;i++) *siX:?l
{ ~U0%}Bbh
String header=con.getHeaderFieldKey(i); |O{N_-];.
if(header!=null) &-3e3)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K(EJ`2]:r
Utility.log(header+" : "+con.getHeaderField(header)); h2ROQKL"B
else "mK`3</G
break; N1a]y/
} gV2vwe
} 2:*15RH3
m,k0 h%
IZ=Z=k{
public void splitterStop() ipu!{kJ
{ S,c{LTL
bStop = true; 42NfD/"g+s
} L ;L:
--K)7
!l (Vk
} T$5wH )<
L4>14D\
9>)b6)J D
/* ^kKLi
**FileAccess.java )9YDNVo*-
*//文件访问(定位，写) ZnEgU}g<2
package NetFox; (Q*q#U
import java.io.*; 1l,fK)z
OS(`H5D
B\J[O5},
public class FileAccessI implements Serializable{ + [w 0;W_
e~]P _53
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I-]G{
RandomAccessFile oSavedFile; ]9oj,k
long nPos; -9b=-K.y
;_,jy7lf
\p4*Q}t
public FileAccessI() throws IOException .]v>LsbhF
{ dn(!wC]
this("",0); kR<sSLEb
} f2WVg;Z
aTvyzr1
LT%~Cuf
public FileAccessI(String sName,long nPos) throws IOException yKML{N1D
{ |! 9~
oSavedFile = new RandomAccessFile(sName,"rw"); ef)RlzLOq
this.nPos = nPos; xV> .]
oSavedFile.seek(nPos); ht-'O"d:
} REh"/d
5U2%X pO
Et0gPX-
public synchronized int write(byte[] b,int nStart,int nLen) '.v;/[0
{ -wn-PB@r
int n = -1; +~5Lo'^
try{ G4|C227EO
oSavedFile.write(b,nStart,nLen); {sw|bLo|+
n = nLen; 0~nX7
} `oxBIn*BD
catch(IOException e) D?KLV_Op
{ @K"$M>n$Z
e.printStackTrace (); O60T.MM`
} < se~wR
qz`-?,pF
]xS%Er
return n; lMgguu~qg
} qsj$u-xhX
E2zL-ft.
_{o 3y"DZ
} l"J#Pvi
w"v96%"Y
/[/L%;a'p
/* #?Ix6 {R
**SiteInfoBean.java Y~Uf2(7b5
*/ pW[TufTa
package NetFox; ~=yU%5 s@
O]IAIM
s(X\7Hz_nC
public class SiteInfoBean { Ktk?(49
.nY}_&
D&fOZVuqZ
private String sSiteURL; //Site's URL Da<`| l
private String sFilePath; //Saved File's Path 3ko h!q+
private String sFileName; //Saved File's Name );HhV,$n
private int nSplitter; //Count of Splited Downloading File H0b{`!'Fs:
6EY\
M[985bl
public SiteInfoBean() 6(7 56
{//nSplitter的缺省值为5 `{ Ox=+]M
//default value of nSplitter is 5 K7s[Fa6J
this("","","",5); [#!Y7Ede
} eJf]"-
=Fe4-B?I
,./n@.na
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;QVTb3Th
{ eSZ':p
sSiteURL= sURL; ShQ!'[J
sFilePath = sPath; _k}Qe;
sFileName = sName; |Fx *,91
this.nSplitter = nSpiltter; `)$G}7cRUH
Ro{xprE1
LT)I ?ud
} zv"NbN
Ca5LLG
|"}7)[BW}
public String getSSiteURL() |)d%3s\
{ jp"Q[gR##
return sSiteURL; tW!*W?
} %O!xrA{
<^$ppwk$
'PrBa[%
public void setSSiteURL(String value) s3sD7 @
{ r?~_^
sSiteURL = value; X!{K`~DRX
} Y9-F\t=~
e1b?TF@lz
Q e/XEW
public String getSFilePath() }T PyHq"
{ {\k }:)
return sFilePath; B&7:=t,m(
} w)&4i$Lk6
eU)QoVt
G]$EIf'
public void setSFilePath(String value) 6pb~+=3n
{ $KT)Kz8tF
sFilePath = value; )zy;!
} <l!:#u
tZx}/&m-
amExZ/
public String getSFileName() p7{H "AC
{ 0)zJG |
return sFileName; o&M.9V?~~
} _KtV`bF
YvuE:ia
V60"j(
public void setSFileName(String value) ;K7kBp\d
{ a;Pn.@NVq
sFileName = value; '.N}oL<gP
} CY.92I@S
S~H>MtX(<
SXe1Q8;
public int getNSplitter() __+8wC
{ <_kA+&T
return nSplitter; MSBrI3MqQ
} Y^DGnx("m
3.P7GbN
Xf"< >M
public void setNSplitter(int nCount) 1he5Zevm}
{ v>nBdpjXh
nSplitter = nCount; rtbV*@Z
} 2yFT` 5+H4
} _E8Cvaob
:.=j)ljTx
eU`O=uE
/* f.%3G+
**Utility.java +Q"~2_q5/;
*/ $;$vcV9*
package NetFox; bJ9*z~z)e
Tb;,t=;u
1M_Vhs^
public class Utility { *_J{_7pwe
/ece}7M
EbX!;z
public Utility() z6;hFcO
{ oC} u
q7_Ttjn-DV
/s+IstW
} rH,@"(p\
;/pI@Ck
//线程睡眠 VpB)5>
public static void sleep(int nSecond) f8WI@]1F
{ TF!v,cX
try{ p_]b=3wt~
Thread.sleep(nSecond); -F*vN'
} 5D<ZtsXE
catch(Exception e) [MKG5=kaE
{ Qm*ZOz'i
e.printStackTrace (); ?* ,
} E y9rH_
} NOkgG0Z
&%@O V:C
//日志 u)r:0;5
public static void log(String sMsg) 5a@9PX^.J
{ ~Mar
System.err.println(sMsg); .m\0<8C
} Wb cm1I)
<Uj9~yVN]
7hu7rWY`E
public static void log(int sMsg) b5Q>e%i#
{ /NiD#s0t
System.err.println(sMsg); -])=\n!=
} |6^%_kO!|
} Z^'\()3t
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-r3 s{HO
/* u3,O)[qV
**TestMethod.java b5 NlL`g
*/ HOCj* O4
package NetFox; L@zhbWY
E]m?R 4
h7T),UL
public class TestMethod { `F&~SU,
*TI?tD
`]@=Hx(
public TestMethod() 6@8z3JW.A
{ ///xx/weblogic60b2_win.exe U~"Y8g#qgy
try{ XpE847!soL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FY^Nn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |S|'o*u
SiteFileFetch fileFetch = new SiteFileFetch(bean); [Y@>,B!V
fileFetch.start(); H|wP8uQC
} ]{\M,txo8
catch(Exception e){e.printStackTrace ();} 1(:!6PY
M3|G^q:l
dkCUU
} 5E~^-wX
Xxd]j]
@@{5]Y
public static void main(String[] args) >zL5*:G
{ m_Q&zp["
new TestMethod(); _!, J iOI
} q-_!&kDK"
} 1^= QIX
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