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)); A$]&j5nh|
} l3C%`[MB
for(int i=0;i<nEndPos.length-1;i++) k{q4Zz[
{ io{uN/!X_J
nEndPos = nStartPos[i+1]; Eax^1 |6
} 8V$:th('
nEndPos[nEndPos.length-1] = nFileLength; $<(FZb=
} u79,+H@ep
} !$i*u-%4
O8drR4Pt
}+fMYgw
//启动子线程 DL0i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b=Y:`&o=[
for(int i=0;i<nStartPos.length;i++) ,>rr|O
{ |_^A$Hv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wtY*{m2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9j;L-
nStartPos,nEndPos,i); W+C@(}pt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L-T3{I,3
fileSplitterFetch.start(); ~K-c-Zs#z
} 5uU.K3G7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NBUSr}8|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z`=[hu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @1w9!\7Vt
nEndPos = " + nFileLength); {{WA=\N8C
// fileSplitterFetch[nPos.length-1].start(); ^}gQh#
Wp[R$/uT
lStYfO:<'v
//等待子线程结束 _ xAL0 (
//int count = 0; Xo{|m[,
//是否结束while循环 T7!"gJ
boolean breakWhile = false; El}."}l&
RvQl{aL
JIl<4 %A
while(!bStop) tCJ+OU5/
{ d3$&I==;:
write_nPos(); 9bL`0L
Utility.sleep(500); 5jTBPct
breakWhile = true; $:#{Y;d
*[-% .=[7
BixKK$Lo
for(int i=0;i<nStartPos.length;i++) UUf-G0/P
{ {PXN$p:'
if(!fileSplitterFetch.bDownOver) hf/6VlZ
{ lm?1 K:+[
breakWhile = false; =lzRx%tm
break; :+9KNyA
} B}%B4&Ij
} $rAHtr
if(breakWhile) )jh4HMvmC
break; dc.oK4G}
W3XVr&
|6%B2I&c
//count++; cH&-/|N
//if(count>4) dU7+rc2,CU
// siteStop(); t(O{IUYM
} fgs){Ng`
MT8BP)C
s<i& q {r
System.err.println("文件下载结束！"); kjo,?$r %
} $c!cO" U
catch(Exception e){e.printStackTrace ();} jm_b3!J
} `uO(#au,U
7r`A6 \ !
T ~9)0A"]
//获得文件长度 v&hQ;v
public long getFileSize() %Ts6M,Fpp
{ U#I8Rd I,
int nFileLength = -1; a@E+/9
try{ Svs!C+:le
URL url = new URL(siteInfoBean.getSSiteURL()); 3fS+,>s\O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p[Pa(a,B7
httpConnection.setRequestProperty("User-Agent","NetFox"); ^ |k7g
J YA
y"Fp4$qb
int responseCode=httpConnection.getResponseCode(); xz-z" 8d
if(responseCode>=400) WOW:$.VO^
{ <5R`E(
processErrorCode(responseCode); i8F^ N=
return -2; //-2 represent access is error U*G8}W
} P8hA<{UFS\
z=}@aX[
+d7sy0
String sHeader; ~uF%*
8JOfx
(;f7/2~`
for(int i=1;;i++) ?-40bb
{ YVzcV`4w(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %?GLMf7)
//Utility.log(in.readLine()); *Nv!Kuk
sHeader=httpConnection.getHeaderFieldKey(i); gnW]5#c@
if(sHeader!=null) Fap@cW3?8
{ [(Z sQK
if(sHeader.equals("Content-Length")) ~FnB!Mh}?
{ ]g#ur@Y%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bPaE;?m
break; *h+@a
} 8db J'
} :6~DOvY
else (7C&I-l
break; Gi7jgv{{
} I! s&m%s
} ~]+-<O^U~
catch(IOException e){e.printStackTrace ();} K+3dwQo
catch(Exception e){e.printStackTrace ();} I) mP?
$D`~X`
~VNN
Utility.log(nFileLength); L0v& m
?\_N*NEtK
r?{$k3Vl
return nFileLength; tTWeOAF
} 2_^{Vez@I
s[{L.9Y
1!u}~E_
//保存下载信息（文件指针位置） $ O1w6\}_
private void write_nPos() e-$U .cx
{ h'{}eYb+
try{ :K%{?y
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sq9I]A
output.writeInt(nStartPos.length); nWTo$*>W
for(int i=0;i<nStartPos.length;i++) F-!,U)
{ x/nlIoT
// output.writeLong(nPos); vmI2o'zi
output.writeLong(fileSplitterFetch.nStartPos); zdDn. vG
output.writeLong(fileSplitterFetch.nEndPos); adHZX
} ]=2wQ8
output.close(); j@4 yRl ^
} r 5!ie!5gE
catch(IOException e){e.printStackTrace ();} Qo*,2B9R L
catch(Exception e){e.printStackTrace ();} J(BtGGU'
} :D-xa!7
9zdp8?T
F_8nxQ-
//读取保存的下载信息（文件指针位置） n@pm5f
private void read_nPos() I]qml2
{ GA19=gow
try{ z^s40707x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #UR4I2t*
int nCount = input.readInt(); C-@
nStartPos = new long[nCount]; ->DfT*)
nEndPos = new long[nCount]; => .EDL.
for(int i=0;i<nStartPos.length;i++) 1}#(4tw)
{ "%O,*t
nStartPos = input.readLong(); FhJ8}at+e
nEndPos = input.readLong(); .@0i,7S
} "j+zd&*={
input.close(); >|<8QomD
} qXPT1%+)y
catch(IOException e){e.printStackTrace ();} O.7Q*^_
catch(Exception e){e.printStackTrace ();} b6Jv|1w'
} NTRw:'
jr@u
b .9]b
private void processErrorCode(int nErrorCode) 7g(,$5
{ ebk{p<
System.err.println("Error Code : " + nErrorCode); /1X0h
} vkE[Ur>
QJFx/zU
H \$04vkR
//停止文件下载 'jp nQcwxx
public void siteStop() F{*S}&q*)o
{ MF>1u%
bStop = true; {p-b,J9~a
for(int i=0;i<nStartPos.length;i++) $M\[^g(q
fileSplitterFetch.splitterStop(); owA3>E5t&
h,Y MR3:X
g`KVF"8
} 7p""5hw
} K~nk:}3Ui
//负责部分文件的抓取 J-g#zs
**FileSplitterFetch.java ]a|3"DP5
*/ /kLX f_
package NetFox; #84pRU~
H27J kZ&
jREj]V>
import java.io.*; /kGRN@
import java.net.*; B 95}_q
&_ er_V~
jRXpEiM
public class FileSplitterFetch extends Thread { (;=:QjaoZ
Ww*='lz
(j-[m\wF
String sURL; //File URL |RQ19m@
long nStartPos; //File Snippet Start Position E^S[8=
long nEndPos; //File Snippet End Position d)|{iUcW
int nThreadID; //Thread's ID ~:ddTv?F
boolean bDownOver = false; //Downing is over ADRjCk}I
boolean bStop = false; //Stop identical gkUG*Zw
FileAccessI fileAccessI = null; //File Access interface <:yB4t3H+q
0;'kv|
Y>-|`2Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +~J?/
{ ,)A^3Q*
this.sURL = sURL; =?UCtYN,P
this.nStartPos = nStart; JDVMq=ui
this.nEndPos = nEnd; E"iH$NN
nThreadID = id; BDY@&vF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 03L"W^gc
} -}k'a{sj=
S1^u/$*6
DsY-JBDvoz
public void run() @YmD 79
{ ~*D)L'`2M
while(nStartPos < nEndPos && !bStop) N1WP
{ Kg&{ ?&
"Iu[)O%
RsU=fe,
try{ M*| y&XBe
URL url = new URL(sURL); qWe1`.o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [@[!esC
httpConnection.setRequestProperty("User-Agent","NetFox"); L1*P<Cb
String sProperty = "bytes="+nStartPos+"-"; O!='U!X@P
httpConnection.setRequestProperty("RANGE",sProperty); Q17"hO>kC
Utility.log(sProperty); m` cw:
vOsd>3"
HTI1eLZ2
InputStream input = httpConnection.getInputStream(); ~u1ox_v`%(
//logResponseHead(httpConnection); IjN3 jU
a8aEZ724
hu\HK81m
byte[] b = new byte[1024]; eA&hiAP/
int nRead; _Jj/"?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c"t1E-Nsk
{ 8 f%@:}H
nStartPos += fileAccessI.write(b,0,nRead); c\UVMyE
//if(nThreadID == 1) )F&@ M;2p'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z h0m3|9O
} 7P9n. [
S5d:?^PGg
^4]#Ri=U
Utility.log("Thread " + nThreadID + " is over!"); sj2v*tFb
bDownOver = true; ([UuO}m-
//nPos = fileAccessI.write (b,0,nRead); dv-yZRU:
} $G5m/[KDI
catch(Exception e){e.printStackTrace ();} !U}A1)
} :gY$/1SYD
} WKX5Dl
%f\{ ]
\v]}
//打印回应的头信息 `3kE$h#
public void logResponseHead(HttpURLConnection con) *103
{ %0INtq
for(int i=1;;i++) v83uGEq(
{ hxx,E>k
String header=con.getHeaderFieldKey(i); xPb;_~
if(header!=null) p+;Re2Uyg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '*!R gbj;
Utility.log(header+" : "+con.getHeaderField(header)); Nv*x^y]
else rfYu8-
break; <qZXpQ#
} EG&^;uU
} 'LFHZ&-
B+);y
9 f-T>}
public void splitterStop() y4,2Xs9,
{ cGkl=-oQ'
bStop = true; y4VCehdJ
} lZ0+:DaP2
' F`*(\#
qh0)~JL4
} OnH>g"
vPmP<c)cb
b-]E-$Uz
/* uByF*}d1
**FileAccess.java @5 kKMz
*//文件访问(定位，写) |C'w] QYm
package NetFox; PZNo.0M70
import java.io.*; 'e3y|
>1pD'UZIy7
h|=^@F_\`
public class FileAccessI implements Serializable{ (m)%5*:
Sx;zvc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v7Knu]
RandomAccessFile oSavedFile; ?#}=!$p
long nPos; 2@08V|
H4l:L(!D
"1%<IqpU+
public FileAccessI() throws IOException TzPx4L6?
{ zIF &ZYP
this("",0); *Q!b%DIa$
} :N8D1e-a
n,PHfydqX
Da-F(^E
public FileAccessI(String sName,long nPos) throws IOException #Yw^n?~~
{ n/$BdFH
oSavedFile = new RandomAccessFile(sName,"rw"); 7S] h:q%%
this.nPos = nPos; 82$By]Y9
oSavedFile.seek(nPos); X&wK<
} 4c2P%X( C
wB9IP{Pf
>=U$s@
public synchronized int write(byte[] b,int nStart,int nLen) rFx2S
{ `}zv17wp
int n = -1; LWVO%@)w
try{ n:wn(BC3
oSavedFile.write(b,nStart,nLen); 7[D0n7B@
n = nLen; `t6lnO
} S BFhC
catch(IOException e) P*aD2("Z
{ LrPDpTd
e.printStackTrace (); Ku&(+e
} gKYn*
#jZ:Ex
4aV3x&6X
return n; 8z/^Ql
} @%#(Hse
RLKO0 #
a@8knJ|
} hA@X;Mh^w
_eO]awsA
5Q%#Z L/'
/* R +\y".
**SiteInfoBean.java Rp@u.C<
*/ =pk'a_P8-
package NetFox; [;?^DAnK2
rW`F|F%
w}YHCh
public class SiteInfoBean { vaQ,l6z .h
%kcg#p+tE
#t/Q4X +
private String sSiteURL; //Site's URL "q(&<+D@
private String sFilePath; //Saved File's Path JfVayI=
private String sFileName; //Saved File's Name [=9R5.)c
private int nSplitter; //Count of Splited Downloading File >N,G@{FR
r!M2H{
c^bA]l^a
public SiteInfoBean() cYp}$
{//nSplitter的缺省值为5 @i`gR%
//default value of nSplitter is 5 /tUl(Fp J`
this("","","",5); <]9MgfAe
} %bimcRX#W
w1}[lq@
%/^d]#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p;5WLAF
{ o}%fs *
sSiteURL= sURL; =CVw0'yZ
sFilePath = sPath; l~=iUZW<
sFileName = sName; n;=A'g|Q
this.nSplitter = nSpiltter; :D,YR(])
kDz.{Ih
h49Q2`
} ~H$XSNPi
|4c==7.
H|!s.
public String getSSiteURL() XMdc n,
{ \%C[l
return sSiteURL; dL\8^L
} g}D$`Nx:
~mp$P+M(%p
Z\L@5.*ydE
public void setSSiteURL(String value) |-mazvA
{ ##5/%#eZ
sSiteURL = value; 9?:S:Sq
} O7\s1 V;
|]q=D1/A
p3S c4
public String getSFilePath() \1!k)PZdTW
{ Qx6/QaS?
return sFilePath; /Ow?nWSt
} n1t(ns|
Cm4*sN.&)
`[KhG)Y7t
public void setSFilePath(String value) #SYWAcTkO}
{ [1*/lt|+p
sFilePath = value; Kzb@JBIF
} m\f_u*
W~tOH=9>
5\S7Va;W
public String getSFileName() uI2'jEjO
{ W,~1KUTc
return sFileName; 9qDGxW '1
} `VsGa
=M5M;
q?L(V+X
public void setSFileName(String value) ? st#6=M
{ J7GsNFL
sFileName = value; ,*[LnR
} f>dkT'4
IFxI>6<&
"^z=r]<5
public int getNSplitter() [MS.5+1Y
{ u`@f~QP0
return nSplitter; Aa>gN
} k_>{"Rc
rbPs~C-[
ts<dUO
public void setNSplitter(int nCount) + nS/jW
{ sK0VT"7K
nSplitter = nCount; 6# ";W2
} fR4l4 GU?)
} &|}IBu:T
}G+A_HF ^
"5:f{GfO#v
/* NCnId}BT
**Utility.java ':D&c
*/ r)(BT:2m
package NetFox; L59oh
%J7mZB9
6 v^
public class Utility { -!,]Y10
>x ghq
9}cuAVI
public Utility() 7&V^BW
{ 6bKO;^0
n/oipiYx
5`'=Ko,N
} N5s|a5
yI.H4Dl<
//线程睡眠 8='21@wrN
public static void sleep(int nSecond) H r^15
{ QYfAf3te
try{ ?lDcaI>+n
Thread.sleep(nSecond); }u_EXP8M
} I"32[?0 (;
catch(Exception e) k>&s(b
{ }&T<wm!
e.printStackTrace (); e=o{Zo?H=
} `JWYPsWk
} M1]6lg[si
0*Km}?;0-
//日志 {IPn\Bka
public static void log(String sMsg) s i"`
{ e*2&s5 #RT
System.err.println(sMsg); 0uIV6LI
} )n}]]^Sc
iCnUnR{
8jjk?PUD8
public static void log(int sMsg) %rDmW?T
{ _A,-[*OKI
System.err.println(sMsg); nKjeH@&#
} r($_>TS&"
} co^P7+j
Naf`hE9
MeI2i
/* I,<>%Z|'
**TestMethod.java 1R2o6`_
*/ sh !~T<yy
package NetFox; n-y^7'v
lv00sa2z
n4vXm
public class TestMethod { fmnRUN=
zY+t,2z
53`9^|:
public TestMethod() JMirz~%ib
{ ///xx/weblogic60b2_win.exe 7"n)/;la
try{ Q.9Ph ~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )iEa2uJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fXu~69_
SiteFileFetch fileFetch = new SiteFileFetch(bean); I|F~HUzA"
fileFetch.start(); h\=p=M
} 6VH90KAT
catch(Exception e){e.printStackTrace ();} iM?I /\
GP{$v:RG
hy$MV3LP
} ol?z<53X]
,5eH2W
/$FXg;h9$
public static void main(String[] args) 28T\@zi
{ >9o,S3
new TestMethod(); FXOT+9bg
} bmj8WZ
} aCU7w5
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