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)); l{Xsh;%=
} (r:WG!I,
for(int i=0;i<nEndPos.length-1;i++) oM QH-\(}
{ 9?l( }S`
nEndPos = nStartPos[i+1]; C+O`3wPZp
} >q4nQ/eP
nEndPos[nEndPos.length-1] = nFileLength; =yfr{5}R
} nM\Wa
} dYk)RX`}7!
d.2
69\0$O
//启动子线程 m6aoh^I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r'w5i1C+
for(int i=0;i<nStartPos.length;i++) />)>~_-3
{ Za4 YD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !X*L<)=nh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !|,=rM9x
nStartPos,nEndPos,i); }+I 8l'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wf<uG|90
fileSplitterFetch.start(); 6WI_JbT~
} R+rHa#M_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?Q:se
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R0-ARq#0<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SAly~(r?/
nEndPos = " + nFileLength); (47jop0RDQ
// fileSplitterFetch[nPos.length-1].start(); 0Rrz
5as';1^P&*
<P$b$fh/
//等待子线程结束 c-z=(Z
//int count = 0; GsE?<3
//是否结束while循环 oKzV!~{0M;
boolean breakWhile = false; m <aMb
,Ad\!
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while(!bStop) A7~)h}~
{ T|ZT&x$z
write_nPos(); ;,@3bu>r
Utility.sleep(500); LP#CA^*S
breakWhile = true; p^\>{
plb'EP>e
JI@~FD&
for(int i=0;i<nStartPos.length;i++) 7A3e-51>
{ m6+2rD
if(!fileSplitterFetch.bDownOver) QO%>RG
{ %Xkynso~
breakWhile = false; y)Ip\.KV\
break; NM[w=
} 1[u{3lQ
} VO. Y\8/
if(breakWhile) C Hyb{:<
break; C@hnT<e
$P4hNb
^=.|\ YM
//count++; _S@s
//if(count>4) wz>j>e6k`
// siteStop(); tul5:}x3
} \muyL?
q\d'}:kfu
"2Js[uf
System.err.println("文件下载结束！"); HPtaW:J
} q+|Dm<Ug
catch(Exception e){e.printStackTrace ();} O_(J',++
} tv\P$|LV`8
4'G<qJoc
WoesE:NiR
//获得文件长度 3PI{LU
public long getFileSize() _pjpPSV6J
{ H)t8d_^|j
int nFileLength = -1; w}oH]jVKL6
try{ g&riio7lx
URL url = new URL(siteInfoBean.getSSiteURL()); wyvs#T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U%w?muJW
httpConnection.setRequestProperty("User-Agent","NetFox"); yd`.Rb&V
+#'exgGU^[
?6tuo:gP
int responseCode=httpConnection.getResponseCode(); JF24~Q4P
if(responseCode>=400) =Lp0i9c
{ G)'cd D1
processErrorCode(responseCode); {Qlvj.Xw
return -2; //-2 represent access is error /$+ifiFT
} W#-M|
6Dw[n
jc)D*Cf
String sHeader; a8A8?:
b.j\=c
o5. q
for(int i=1;;i++) *hFT,1WE=+
{ 1w1(FpQO.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g0_8:Gs}^
//Utility.log(in.readLine()); l,,5OZw
sHeader=httpConnection.getHeaderFieldKey(i); 2Hy$SSH
if(sHeader!=null) H }</a%y
{ -DU[dU*~
if(sHeader.equals("Content-Length")) /38^N|/Zr
{ T9N /;3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OC"W=[Myl
break; 0'VwObq
} jJ|O]v$N
} 9J0m
else '1/uf;OXIH
break; kAf2g
} >qAQNX
} F9-xp7T
catch(IOException e){e.printStackTrace ();} S%g`X
catch(Exception e){e.printStackTrace ();} #Z (B4YO
k((_~<$2K
*.W![%Be
Utility.log(nFileLength); tb{l(up/a
xNE<$Bz
g^4'42UX
return nFileLength; n#bC,
} ks:Z=%o
#pE:!D
dhsQfWg#}
//保存下载信息（文件指针位置） y$K!g&lGA
private void write_nPos() o;_v'
{ 1r|'n aiZ
try{ NR^z!+oSR
output = new DataOutputStream(new FileOutputStream(tmpFile)); BWfsk/lej
output.writeInt(nStartPos.length); m7g; psg
for(int i=0;i<nStartPos.length;i++) ZU7,=B=
{ ON] z-
// output.writeLong(nPos); gKn"e|A
output.writeLong(fileSplitterFetch.nStartPos); K7U`
output.writeLong(fileSplitterFetch.nEndPos); ?psvhB{O
} 7`|$uIM`
output.close(); !1w=_
} @/E5$mX`
catch(IOException e){e.printStackTrace ();} kd9hz-*
catch(Exception e){e.printStackTrace ();} 8u!!a^F
} x.xfMM2n
)&;?|X+p
.@gv}`>
//读取保存的下载信息（文件指针位置） WENPS*0oS]
private void read_nPos() al(t-3`<
{ w8%<O^wN,
try{ NYm2fFPc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O*`] ]w]
int nCount = input.readInt(); (/-2bO
nStartPos = new long[nCount]; #t>w)`bA-
nEndPos = new long[nCount]; Gp6|M2Vu_5
for(int i=0;i<nStartPos.length;i++) Ma2sQW\
{ j7?53e
nStartPos = input.readLong(); /608P:U
nEndPos = input.readLong(); \/xWsbG\
} 2E9Cp
input.close(); "\Zsr6y
} ogtKj"a
catch(IOException e){e.printStackTrace ();} 2,{m>fF
catch(Exception e){e.printStackTrace ();} "M3R}<Vt
} b*+Od8r
MN}@EQvW==
PmZ-H>
private void processErrorCode(int nErrorCode) NldeD2~H
{ +[<|TT
System.err.println("Error Code : " + nErrorCode); NuRxkeEO
} %AwR4"M
Z@nWx]iz
SzR7:U
//停止文件下载 Ghs{B8
public void siteStop() _DnZ=&=MA
{ ,_,Z<X/
bStop = true; {dM18;
for(int i=0;i<nStartPos.length;i++) "g;^R/sfq
fileSplitterFetch.splitterStop(); 8=Xy19<;t
v9QR,b`n
A>8"8=C
} 3J%(2}{y
} se(ZiyHp
//负责部分文件的抓取 +Wrj%}+
**FileSplitterFetch.java +F=j1*'&
*/ rtd&WkU rD
package NetFox; l*V]54|ON3
`irz'/"p
1$2'N~`#U
import java.io.*; -'ePx f
import java.net.*; 'id]<<F
| #Z+s-
1AiqB Rs
public class FileSplitterFetch extends Thread { Eh/B[u7T[
{>$i)B
US3rkkgDO
String sURL; //File URL lJ1_Zs `
long nStartPos; //File Snippet Start Position ++=t|ZS U
long nEndPos; //File Snippet End Position E_k<EQ%r
int nThreadID; //Thread's ID ElLDSo@WvR
boolean bDownOver = false; //Downing is over g$$i WC!S<
boolean bStop = false; //Stop identical TN!8J=sx.
FileAccessI fileAccessI = null; //File Access interface 6^_:N1@
fP<Tvf
2 u:w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BSU%.tmI
{ .H;[s
this.sURL = sURL; $3.hZx>
this.nStartPos = nStart; [HNWM/ff7+
this.nEndPos = nEnd; H809gm3(Z
nThreadID = id; 0*7N=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {6}H}_(]
} P|c[EUT
bn$a7\X-
,c }R*\
public void run() =SMI,p&
{ $hv o^$
while(nStartPos < nEndPos && !bStop) O.OPIQ=?:w
{ g>].m8DZ'
phkfPvL{
R)}ab{A
try{ MC=pN(l
URL url = new URL(sURL); .%Pt[VQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YKCd:^u
httpConnection.setRequestProperty("User-Agent","NetFox"); |KH981
String sProperty = "bytes="+nStartPos+"-"; Qy< ~{6V
httpConnection.setRequestProperty("RANGE",sProperty); Js{X33^Ju
Utility.log(sProperty); Q)vf>LwC2S
qRk<1.
+bO]9*g]
InputStream input = httpConnection.getInputStream(); &?[uY5Mk
//logResponseHead(httpConnection); V!^5#A<
1dsMmD[O
E+'P|~>oX
byte[] b = new byte[1024]; C|or2
int nRead; 6d%V=1^F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Xx)PyO
{ 0Z{;sW
nStartPos += fileAccessI.write(b,0,nRead); FR5P;Yz%H
//if(nThreadID == 1) i"4&UJu1;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ONr}{T%@/
} `?M?WaP
mEh([ZnY
! J7ExfEA
Utility.log("Thread " + nThreadID + " is over!"); uu5L9.i9
bDownOver = true; (j>a?dKDS
//nPos = fileAccessI.write (b,0,nRead); 3fdx&}v/
} w^/jlddF
catch(Exception e){e.printStackTrace ();} o=%pR|
} DAvF ND$=
} <Sn;k[M}d
;^yR,32F
r:xbs0 7
//打印回应的头信息 8l<4OgoK
public void logResponseHead(HttpURLConnection con) * |dz.Tr
{ *{K?JB#W
for(int i=1;;i++) }={TVs^
{ #.KVT#%~{
String header=con.getHeaderFieldKey(i); qL;T^ljP
if(header!=null) JI5%fU%O#n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \7\7i-Vo
Utility.log(header+" : "+con.getHeaderField(header)); 8k.<xWDU
else !Au@\/}
break; d[( }
} JA<Hm.V#
} igGg[I1?
4lCEzWo[/
iYPlgt/Y!
public void splitterStop() Zb? u'Vm=u
{ @)^|U"
bStop = true; ORdS|y;:
} X"sc'#G T
vAV{HBQ*
WR<,[*Mv^
} Ow3t2G
1+Z@4;fk
$yoIz.?V
/* (p?7-~6|:
**FileAccess.java C)z?-f
*//文件访问(定位，写) l.iT+T
package NetFox; `|2p1Ei
import java.io.*; %@,! (
(\zxiK
uH.1'bR?a
public class FileAccessI implements Serializable{ wRj||yay#-
s`$YY_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {^jRV@
RandomAccessFile oSavedFile; lK2=[%,~
long nPos; L8{4>,
V/dL-;W;
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public FileAccessI() throws IOException +N>z|T<
{ ;x|LB>.
this("",0); !8@8
} /hv2=A
=3H*%
VLP'3 qX
public FileAccessI(String sName,long nPos) throws IOException \&,{N_G#L.
{ mr[+\ 5
oSavedFile = new RandomAccessFile(sName,"rw"); c`agrS:P
this.nPos = nPos; ']__V[
oSavedFile.seek(nPos); K2@],E?e%|
} p?H2W-
JE=3V^k
2,^U8/
public synchronized int write(byte[] b,int nStart,int nLen) IA3m.Vxj ^
{ 0qSf7"3f
int n = -1; m2j]wUh"
try{ NxGSs_7
oSavedFile.write(b,nStart,nLen); 3jzmiS]
n = nLen; JF6=0
} m.b}A'GT
catch(IOException e) ? \p,s-CR:
{ 9 .3?$(
e.printStackTrace (); Lyy:G9OV
} 9lR-
T/nG\WZbZn
`7$Sga6M
return n; R\Of ,
} [;LP6n7v
"x4}FQ
N${Wh|__^l
} E(miQ
`s|^
0 ~^l*
/* =EQaZ8k
**SiteInfoBean.java ,: Z7P@
*/ "Gc\"'^r
package NetFox; ]?*L"()kp
t+tD
\L:+k `
public class SiteInfoBean { <o"2z~gv
|h%0)_
t+IrQf,P[
private String sSiteURL; //Site's URL #VU>Z|$@N
private String sFilePath; //Saved File's Path V:h3F7
private String sFileName; //Saved File's Name C)(/NGf
private int nSplitter; //Count of Splited Downloading File nPg,(8Tt
g=Bge)
c1}i|7/XSi
public SiteInfoBean() ]\6*2E{1m
{//nSplitter的缺省值为5 _M)J{ {?:
//default value of nSplitter is 5 0fAo&B
this("","","",5); "YoFUfaNg
} !D~\uW1b
,#8H9<O9t
(yv)zg9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hpOK9
{ :S=!]la0h
sSiteURL= sURL; V1 {'d[E*
sFilePath = sPath; D22jWm2
sFileName = sName; 5.U4P<qS
this.nSplitter = nSpiltter; ~^v*f
Ur,{ZGm
KF}_|~~T
} &]jCoBj+_
; -,VJCPi
iXD=_^^o .
public String getSSiteURL() *zl-R*bM$
{ !I+F8p
return sSiteURL; LR%P\~
} 0ra+MQBg
@jT=SFf
hO..j
public void setSSiteURL(String value) JK^pb0ih
{ 3 adF) mh
sSiteURL = value; 5@yBUwMSj
} Z/+H
my*E7[
tr$d?
public String getSFilePath() yq,%<%+
{ :,pdR>q%(y
return sFilePath; uE^5o\To
} o>MB8[r
NzC&ctPk
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public void setSFilePath(String value) 3Ss)i7
{ A"Sp7M[J
sFilePath = value; H':0
} 1)!?,O\ey
!DZ4C.
R7ExMJw
public String getSFileName() (F'?c1
{ f1X]zk(=W
return sFileName; -|( q9B
} ](SqLTB+?
)mE67{YJh~
0s%]%2ON
public void setSFileName(String value) r)Fd3)e
{ MURHv3
sFileName = value; g{^(EZ,
} y0\=F
D~r{(u~Ya
!y7w~UVs
public int getNSplitter() Na{&aqdz
{ #r;uM+
return nSplitter; W0s3nio
} 2X|nPhNi
0&2eiMKG?n
L^{wxOf&6E
public void setNSplitter(int nCount) Ahrtl6@AS
{ U'Fc\M5l/l
nSplitter = nCount; z[*Y%o8-r
} aKk0kC
} }(v <f*7=n
_[8sL^
^|lG9z%Foy
/* $S2kc$'F
**Utility.java kd+tD!:F(
*/ N3o kN8d
package NetFox; </33>Fu)
0;:AT|U/d
g33Y]\
public class Utility { Qm2(Z8Gh
q-4#)EnW
wZ\% !#}7
public Utility() $Y<(~E$FX
{ fhbILg
UVaz,bXla
_Rey~]iJJ8
} d{~Qd|<rr
\aB"D=P\ok
//线程睡眠 i=j4Wg,{J
public static void sleep(int nSecond) *&vi3#ur
{ 'QxPQcU
try{ g0"KCX
Thread.sleep(nSecond); o!}/& '(
} ]-tAgNzl%
catch(Exception e) rKr2 K'
{ >TddKR@C
e.printStackTrace (); E K#ib
} [nG[@)G~0M
} 62{[)jt{
MD=VR(P?eq
//日志 dxF/]>t
public static void log(String sMsg) :j(D&?ao
{ ;+4X<)y*>
System.err.println(sMsg); wVY;)1?
} ts~$'^K[-
Q5pm^X._j
u@$pOLI
public static void log(int sMsg) +)QA!g$
{ ffE&=eh)
System.err.println(sMsg); DU.[Sp
} E!v^j=h$u
} *'hvYl/?>
?ne!LDlE|
ZeP3 Yjr3
/* DsH`I%w{
**TestMethod.java 7z4u?>pne*
*/ {;j@-=pV
package NetFox; +)7Yqh#$
Il,^/qvIY
0&|,HK
public class TestMethod { {glRXR
kFF)6z:2
8/* 6&#-
public TestMethod() =*?2+ ;
{ ///xx/weblogic60b2_win.exe aok,qn'j
try{ Il9pL~u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /]*#+;;%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1F_ 1bAh$
SiteFileFetch fileFetch = new SiteFileFetch(bean); J>Uzd, /
fileFetch.start(); .4-I^W"1
} ua!g}m~
catch(Exception e){e.printStackTrace ();} hV4\#K[
jboQ)NxT!,
"3Z<V8xB
} HJ,sZ4*]]
>o"3:/3
^>fjURR
public static void main(String[] args) \XXS;
{ %<Q?|}
new TestMethod(); ET7(n0*P}]
} |.zotEh
} 1@Zjv>jy[
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