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)); a9}7K/Y=d
} h/?$~OD
for(int i=0;i<nEndPos.length-1;i++) I($0&Y\De
{ *6IytWOX5
nEndPos = nStartPos[i+1]; 8Qd*OO
} @Fvp~]jCb
nEndPos[nEndPos.length-1] = nFileLength; ps[HvV"
} t<h[Lb%{T4
} {DlQTgP
q|r^)0W
Dc-v`jZ@)
//启动子线程 m~c6b{F3Z-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C&wp*
for(int i=0;i<nStartPos.length;i++) $`;1][OD
{ r}T(?KGx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '1P~"P3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >h)D~U(H
nStartPos,nEndPos,i); &|MdBJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qca,a3k
fileSplitterFetch.start(); = j)5kY`
} "}*5'e.*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n4Xh}KtH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ` ES-LLhVf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~xPU#m<
nEndPos = " + nFileLength); HV21=W
// fileSplitterFetch[nPos.length-1].start(); KJ (|skO
=2XAQiUR\
D`hl}
//等待子线程结束 )?y${T
//int count = 0; ]8 vsr$E#
//是否结束while循环 OKi}aQ2R*
boolean breakWhile = false; H^sImIEUT
db*yA@2Lg
:Eb=jWA
while(!bStop) \gCh'3
{ W79Sz}):
write_nPos(); pG&#xRk
Utility.sleep(500); 5FMe&
breakWhile = true; :;Xh`br
)gVz?-u+D
mE"(d*fe'
for(int i=0;i<nStartPos.length;i++) um,G^R
{ ^vw[z2"
if(!fileSplitterFetch.bDownOver) 4$oDq
{ TTagZI$
breakWhile = false; P(xgIMc H
break; j82x$I*
} `a6AES'w$
} :P8X?C63W]
if(breakWhile) l6T^e@*
break; y0]"qB
\ gO!6
ZHM NG~!
//count++; Xk] uXx:TN
//if(count>4) !&adO,jN+=
// siteStop(); V7<w9MM
} fnJx$PD~
.k -!/^
VX:Kq<XwQ
System.err.println("文件下载结束！"); #;0F-pt
} z!G?T(SpA
catch(Exception e){e.printStackTrace ();} XwZR Kh\>=
} ,K15KN.'
RF[Uy?es
s5\<D7
//获得文件长度 sK@]|9ciQ
public long getFileSize() dvcLZK
{ 50e vWD
int nFileLength = -1; 3~%M4(
try{ :sX4hZK=G
URL url = new URL(siteInfoBean.getSSiteURL()); 9 lXnNK |]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zI= 9
httpConnection.setRequestProperty("User-Agent","NetFox"); Z&|Dp*Z
eGW h]%
3Yf~5csY
int responseCode=httpConnection.getResponseCode(); 7q&T2?GEN
if(responseCode>=400) )i"52!
{ G:!3X)b
processErrorCode(responseCode); uquY z_2
return -2; //-2 represent access is error d(YAH@
} (qw;-A W8
U!jRF
eIj2(q9
String sHeader; GdM|?u&s"
l0PXU)>C
,&iEn}xG7i
for(int i=1;;i++) /b]+RXvxj
{ #y8Esik
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |JiN; O+K
//Utility.log(in.readLine()); j9/hZqo
sHeader=httpConnection.getHeaderFieldKey(i); bE!z[j]
if(sHeader!=null) b63DD(
{ +h?Gps
if(sHeader.equals("Content-Length")) ]u.)6{
{ ky{@*fg.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =d$m@rc0r
break; iU|X/>k?
} x<5;#
} 4D[(X=FSU
else !jR 1!i
break; J ql$ g
} 4}t$Lf_
} q}]z8 L
catch(IOException e){e.printStackTrace ();} iow"X6_l_
catch(Exception e){e.printStackTrace ();} E~S~Ld%
N97WI+`
mUfANlQ:
Utility.log(nFileLength); zG7y$\A
swg*fhJFB
MSb0J`
return nFileLength; je74As[
} n){u!z)Al
GG(}#Z5h
Z*Fn2I4
//保存下载信息（文件指针位置） 0pBG^I`_
private void write_nPos() CN6b982&
{ ;73{n*a$
try{ `^)oVs
output = new DataOutputStream(new FileOutputStream(tmpFile)); v<atic
output.writeInt(nStartPos.length); nFjaV`6`@
for(int i=0;i<nStartPos.length;i++) 2UMX%+ "J
{ >&JS-jFg
// output.writeLong(nPos); ^V"08
output.writeLong(fileSplitterFetch.nStartPos); 2E.D0E Cu
output.writeLong(fileSplitterFetch.nEndPos); z>HM$n`YD
} ^qtJcMK+hq
output.close(); [M?&JA_$}
} (r-PkfXvIf
catch(IOException e){e.printStackTrace ();} +hIMfhF
catch(Exception e){e.printStackTrace ();} hdpA& OteR
} \/!jGy*
_o-01gu.
bLC+73BjC
//读取保存的下载信息（文件指针位置） X CHN'l'
private void read_nPos() t?FPmbjv
{ 0BN=>]V~j7
try{ RWZjD#5%Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k^%F4d3z@C
int nCount = input.readInt(); eK/rsr
nStartPos = new long[nCount]; &ZJ$V
nEndPos = new long[nCount]; wx^1lC2
for(int i=0;i<nStartPos.length;i++) Sr-!-eC
{ T9AFL;1
nStartPos = input.readLong(); 8ZNwo
nEndPos = input.readLong(); mpzm6Ieu
} `8D'r|=`Eh
input.close(); +2m\Sv V
} fK4NmdTV
catch(IOException e){e.printStackTrace ();} \O\veB8
catch(Exception e){e.printStackTrace ();} R}$A>)%dx
} ~g&Gi)je
|Gt]V`4
30QQnMH3
private void processErrorCode(int nErrorCode) xKXD`-|W
{ t.]e8=dE
System.err.println("Error Code : " + nErrorCode); TYedem<$
} {+ WI>3
51puR8AG>
*KPNWY9!W
//停止文件下载 F"a31`L>H
public void siteStop() gX]'RBTb
{ SA.,Q~_T7
bStop = true; G=>LW1E|
for(int i=0;i<nStartPos.length;i++) B3yp2tncj
fileSplitterFetch.splitterStop(); +w+qTZyky
vH vwH
Nk shJ2
} X-5&c$hv
} 6M@m`c
//负责部分文件的抓取 WQ1*)h8,9
**FileSplitterFetch.java ^/jALA9!
*/ XLFo"f
package NetFox; E#,n.U>#)
} mEsb?
x2z%J,z@4
import java.io.*; 2_;3B4GDF
import java.net.*; .8Gmy07
/qO?)p3gk
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public class FileSplitterFetch extends Thread { Z#062NL "
fQ~YBFhlr
eX9H/&g
String sURL; //File URL !e:HE/&>i
long nStartPos; //File Snippet Start Position =#{i;CC%
long nEndPos; //File Snippet End Position *M()z.N
int nThreadID; //Thread's ID b+mh9q'5E
boolean bDownOver = false; //Downing is over AME6Zu3Y
boolean bStop = false; //Stop identical Js!V,={iX
FileAccessI fileAccessI = null; //File Access interface 30$Q5]T
W\<p`xHk
oF#]<Z\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X&({`Uw<K
{ 06vxsT@
this.sURL = sURL; }5sJd>u5^
this.nStartPos = nStart; UP |#WegO
this.nEndPos = nEnd; HtGGcO'bqg
nThreadID = id; R(F+Xgje
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s~Od(,K
} zmh3 Qa(
U)grC8 C
*dm?,~f%<
public void run() C6(WnO{6
{ i3 n0W1~
while(nStartPos < nEndPos && !bStop) 2j7e@pr
{ _J`q\N K
pZe:U;bb
zq&,KZ
try{ [vY? !
URL url = new URL(sURL); xt"GO b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3re|=_ Hy
httpConnection.setRequestProperty("User-Agent","NetFox"); ZCS{D
String sProperty = "bytes="+nStartPos+"-"; 6s|4'!
httpConnection.setRequestProperty("RANGE",sProperty); tL~?)2uEN
Utility.log(sProperty); JOJ?.H&su
*,d>(\&[f
#35@YMF
InputStream input = httpConnection.getInputStream(); J|2OmbJe
//logResponseHead(httpConnection); QGV~Y+
?$LKn2C
b ZEyP W
byte[] b = new byte[1024]; !{L`Zd;C>w
int nRead; +yd(t}H@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F,-S&d
{ E>3fk
nStartPos += fileAccessI.write(b,0,nRead); `CQMvX{
//if(nThreadID == 1) Wg2Y`2@t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l4s_9
} tJ,x>s?Y
K@zzseQ}=
pC'GKk 8
Utility.log("Thread " + nThreadID + " is over!"); =D2x@ank[
bDownOver = true; < l%3P6|
//nPos = fileAccessI.write (b,0,nRead); x0!5z1KQh
} ;Y>cegG\
catch(Exception e){e.printStackTrace ();} RZeU{u<O
} #]!0$z|Z
} uM9[
'9MtIcNb
,pz^8NJAI
//打印回应的头信息 <H)I06];
public void logResponseHead(HttpURLConnection con) aGYF\7
{ 51k^?5cO
for(int i=1;;i++) 2So7fZa^wg
{ U ExK|t
String header=con.getHeaderFieldKey(i); dM1)wkbET
if(header!=null) R1DXi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `9
Utility.log(header+" : "+con.getHeaderField(header)); &k+'TcWm
else 6n.W5 1g(s
break; *M_Gu{xc
} 1MCHwX3/
} . 787+J?
AZCbUkq
@]H:=Q'gj
public void splitterStop() '_~=C-g
{ Ex ?)FL$4
bStop = true; `_6!nkq8
} jtk2>Ol
idf~"a
#Pz},!7
} iraO/KhD*3
bS+by'Ea1W
bX:ARe O
/* n(gw%w+\7
**FileAccess.java 0vs9# <&V
*//文件访问(定位，写) q=5#t~?
package NetFox; +FWkhmTv
import java.io.*; Gv!* Qk4
r2T-=XWB
KbY5 qou
public class FileAccessI implements Serializable{ `R]9+_"N
s wdW70
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rZDlPp>BPZ
RandomAccessFile oSavedFile; %/:{x()G
long nPos; Z%Nl<i
L!7*U.+
qF{u+Ms
public FileAccessI() throws IOException 8}0W_CU,
{ l("Dw8H
this("",0); )j40hrR
} r`|/qP:T[
Elt=/,v`!
JBCcR,\kM*
public FileAccessI(String sName,long nPos) throws IOException .VVY]>bJg@
{ {ZH9W
oSavedFile = new RandomAccessFile(sName,"rw"); %p}_4+[;
this.nPos = nPos; pC2r{-
oSavedFile.seek(nPos); oY:6a
} 9&=~_,wJd
`?Yh`P0
ldo7}<s
public synchronized int write(byte[] b,int nStart,int nLen) iNR6BP W
{ 5uK:f\y)l
int n = -1; {|%N
try{ %v\0Dm+A
oSavedFile.write(b,nStart,nLen); ;%Jw9G\h
n = nLen; |\j'Z0
} j(!M
catch(IOException e) 2B7X~t>8a
{ w<*tbq
e.printStackTrace (); >_1*/o JO
} zxtx~XO
2;G^>BP<
\+E{8&TH'
return n; bIP{DxKS
} \FSkI0
euS"C*
(xJ6: u
} aD,sx#g0
yVm~5Y&Z
?9_<LE q
/* +Eh1>m
**SiteInfoBean.java 4!<8Dd
*/ 0A@'w*=
package NetFox; 5B!l6ST
BF2,E<^A
Dx =ms^oN5
public class SiteInfoBean { 7z"xjA
{T Z7>k
15_OtK
private String sSiteURL; //Site's URL _PrK6M@"L
private String sFilePath; //Saved File's Path .N8AkQ(Ok
private String sFileName; //Saved File's Name <jT6|2'
private int nSplitter; //Count of Splited Downloading File K*Zf^g m
k7Fa+Y)K7
~#dNGWwG
public SiteInfoBean() 2H_|Attoi
{//nSplitter的缺省值为5 >[=q9k
//default value of nSplitter is 5 NIeT.!
this("","","",5); 5 fjeBfy
} Lc6Wj'G G
, gk49z9
!Ac<A.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |k:MXI
{ gk\IivPb
sSiteURL= sURL; 3hr&p{/
sFilePath = sPath; {%xwoMVc+
sFileName = sName; _e$15qW+
this.nSplitter = nSpiltter; a|`Pg1j#
KFdTw{GlJ7
^!-*xH.dK
} [!4p5;
rIg1]q
rG1l:Z)
public String getSSiteURL() F0%FX`b{{
{ 1`N q K
return sSiteURL; }3F8[Td.~N
} FyX\S=
4mJ4)
~`c?&YixU
public void setSSiteURL(String value) +~\1Zgw
{ <<gk<_7`
sSiteURL = value; YYHtd,0\+
} ;1&%Wj"d
yazC2Enes8
M ()&GlNs
public String getSFilePath() cj@Ygc)n
{ n5A0E2!
return sFilePath; 0'`>20Y
} )f9f_^;
X>j% y7v
Oemi}
public void setSFilePath(String value) `uy)][j-
{ ulV)X/]1
sFilePath = value; xz5Jli
} jXkz,]Iy
9l9nT
uPc}a3'?
public String getSFileName() ULqnr@/FbK
{ 0&2(1
return sFileName; $-m@cObw!.
} \];0S4SBy
V #W,}+_Sz
_eM\ /(v[
public void setSFileName(String value) z9pv|
{ blNJ
sFileName = value; )#zc$D^U
} ~~k_A|&
rvuskXdo
xal+buOiP
public int getNSplitter() z=B*s!G
{ $^?"/;8P5
return nSplitter; %KK6}d#
} {A]"/AC
bB@1tp0+
:}}5TJwG
public void setNSplitter(int nCount) I~?D^
{ ^{nf0)56c
nSplitter = nCount; 7N,E%$QL
} B)g7MG
} js)M c*]&
/)Bk r/
DZ -5A
/* HtB>#`'
**Utility.java |oPCmsO3R{
*/ J3gJSRT@P
package NetFox; {/G~HoY1i
)WavG1
13wO6tS k
public class Utility { [ZU6z?Pf
__M(dN(^
+<7~yZ[Z8
public Utility() u)PB@
{ Gs;wx_k^
m`gH5vQa
e/JbRbZX
} b?eIFI&w^l
\,)('tUE
//线程睡眠 L,c@Z@
public static void sleep(int nSecond) =B@+[b0Z
{ P_6oMR
try{ 42E]&=Cet
Thread.sleep(nSecond); lJ;7sgQ#
} rpH ,c[D
catch(Exception e) esU9
{ ;+] mcgN!
e.printStackTrace (); fTd=}zY
} O_}R~p
} ;"46H'>!
$Y* d ' >
//日志 5'wWj}0!%
public static void log(String sMsg) AL@8v=
{ _Y@vO
System.err.println(sMsg); <y[LdB/a
} 4\ R2\
-l)vl<}
[AkL6
public static void log(int sMsg) V .+ mK|)
{ 4H'\nsM
System.err.println(sMsg); x9Um4!/t
} l#u$w&
} I^S gWC
0'q&7 MV
jez=q
/* mh&wvT<:{
**TestMethod.java 6BK-(>c(6
*/ k?]`PUrV
package NetFox; h=h4`uA9
=y+gS%o$
>tc#Ofgzd
public class TestMethod { f_v@.vnn.
1;8=,&
D! TFb E
public TestMethod() +l'l*<
{ ///xx/weblogic60b2_win.exe ]S!:p>R
try{ %f3qCN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !YX$4_I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qj|P0N{7
SiteFileFetch fileFetch = new SiteFileFetch(bean); v$~1{}iI5
fileFetch.start(); Ai>=n;
} F[am2[/<A
catch(Exception e){e.printStackTrace ();} NMJX `
w]<V~X
KA~eOEjM
} wJc~AP)I%z
Z[9) hGh
HK}br!?
public static void main(String[] args) 2S%[YR>>
{ DpD19)ouy
new TestMethod(); :\hcl&W:
} M9[52D!{
} P;~`%,+S
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