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)); $4=Ne3y
} [M4xZHd#o
for(int i=0;i<nEndPos.length-1;i++) sF y]+DB
{ =(%*LY!Xc
nEndPos = nStartPos[i+1]; D/Rv&>Jh
} NdZ)[f:2
nEndPos[nEndPos.length-1] = nFileLength; }d_<\
} DB#$~(o
} `%|u!
*xPB<v2N:P
XM$GQn]B
//启动子线程 ;v_ls)_,-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u=%y
for(int i=0;i<nStartPos.length;i++) o~= iy
{ s3seK6x'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~]&B>q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dsV ~|D6:
nStartPos,nEndPos,i); 7R: WX:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ozU2
fileSplitterFetch.start(); /J;;|X#P
} {B3(HiC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6#E7!-u(-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yr5NRs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )!i!3
nEndPos = " + nFileLength); ,(P %z.P@
// fileSplitterFetch[nPos.length-1].start(); D3y>iQd
T8U[xu.>
=^Th[B
//等待子线程结束 q-YL]PgV
//int count = 0; Q\|18wkW
//是否结束while循环 6J\q`q(W(
boolean breakWhile = false; Lx%:t YZ
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#pX8{Tf[
while(!bStop) v;Es^ YI
{ pajy#0 U
write_nPos(); G.Tpl-m
Utility.sleep(500); n'yl)HA~>`
breakWhile = true; #7o0dE;Kg9
L?HF'5o
`_GO=QQ
for(int i=0;i<nStartPos.length;i++) ilv_D~|
{ M|k&TTV
if(!fileSplitterFetch.bDownOver) vO]J]][
{ to'j2jP
breakWhile = false; ,ijW(95{k
break; yw'ezpO"
} JA<~xo[Q9
} )6=gooe]
if(breakWhile) GMdI0jaG#
break; 7H%_sw5S.
]U[&uymax
S6GMUaR
//count++; Wab.|\c
//if(count>4) [t{](-
// siteStop(); .a:Z!KF
} x6ahZ
9<l-NU9 _
Zi/-~')E
System.err.println("文件下载结束！"); 6 Uw;C84!
} ^!}F%
catch(Exception e){e.printStackTrace ();} iS
} _s*! t
ra]:$XJ5=a
zw]3Vg{T
//获得文件长度 &:No}6
public long getFileSize() t!{x<9
{ l<xFnj
int nFileLength = -1; EjSD4
try{ B'p5M.6d#:
URL url = new URL(siteInfoBean.getSSiteURL()); MqdB\OW&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MtUY?O.P2
httpConnection.setRequestProperty("User-Agent","NetFox"); ~M*gsW$
Hd0Xx}3&
Vv7PCaq
int responseCode=httpConnection.getResponseCode(); Xhse~=qA
if(responseCode>=400) P>wZ~Hjk
{ #h N.=~
processErrorCode(responseCode); .!yq@Q|=u
return -2; //-2 represent access is error 4fty~0i=z
} uoCGSXsi
Szts<n5
E*k([ZL
String sHeader; sKd)BA0`
bnr|Y!T}Bi
s@~/x5jwCs
for(int i=1;;i++) hJ[UB
{ N@()F&e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *S4aF*Qk
//Utility.log(in.readLine()); TKOP;[1h
sHeader=httpConnection.getHeaderFieldKey(i); 1Nj=B_T
if(sHeader!=null) f=m/ -mAA
{ o?wt$j-
if(sHeader.equals("Content-Length")) ln#\sA?iG
{ &SmXI5>Bo0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U:n*<l-k}
break; EkZjO Ci
} K]<u8eF
} zQc"bcif5(
else k 4B_W
break; OQFi.8
} F;kvH
} KjOi(YUnq7
catch(IOException e){e.printStackTrace ();} @9vvR7{P
catch(Exception e){e.printStackTrace ();} tOH0IE c
wyw<jH
tS<h8g_
Utility.log(nFileLength); XWtiwf'K
nU17L6'$
PN &|8_
return nFileLength; azX`oU,l
} )%VCzye*{
GV8)Kor%
{eR9 ;2!
//保存下载信息（文件指针位置） {|6z+vR
private void write_nPos() gz61FW
{ 5B*qbM
try{ $.:3$et@/
output = new DataOutputStream(new FileOutputStream(tmpFile)); fHfY}BQS
output.writeInt(nStartPos.length); y5u\j{?Te
for(int i=0;i<nStartPos.length;i++) )gXTRkmw
{ G),db%,X2
// output.writeLong(nPos); 9m8ee&,
output.writeLong(fileSplitterFetch.nStartPos); tU:FX[&?R
output.writeLong(fileSplitterFetch.nEndPos); Qq3fZ=
} `6F+Rrn
output.close(); w$>3pQ8d
} {/ &B!zvl
catch(IOException e){e.printStackTrace ();} h8=h >W-
catch(Exception e){e.printStackTrace ();} Qra>}e%*
} &{W^W8,%
4seciz0?
f#P_xn&et
//读取保存的下载信息（文件指针位置） x?L hq2
private void read_nPos() V]c5 Z$Bd
{ 5pJ*1pfeo
try{ L~eAQR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bUs|t
int nCount = input.readInt(); t5)J;0/
nStartPos = new long[nCount]; TyOH`5D
nEndPos = new long[nCount]; ~/|zlu*jpc
for(int i=0;i<nStartPos.length;i++) _tj&Psp
{ nwf7M#3d
nStartPos = input.readLong(); 4#:\?HAu!
nEndPos = input.readLong(); ~NNv>5t5
} %+wF"
input.close(); }-p,iTm
} zu<3^=3
catch(IOException e){e.printStackTrace ();} @^?XaU
catch(Exception e){e.printStackTrace ();} YwAnqAg
} kon=il<@
Ei~f`{i
'qy#)F
private void processErrorCode(int nErrorCode) 7lU.Nit
{ ow.j+<M
System.err.println("Error Code : " + nErrorCode); Y=Hz;Ni
} xR908+>5
uRQ_'l
o:UXPAj
//停止文件下载 ;&,.TC?l
public void siteStop() Bq!cY Wj
{ xo WT*f
bStop = true; If'2rE7J
for(int i=0;i<nStartPos.length;i++) n93zD*;5
fileSplitterFetch.splitterStop(); )(bxpW
j}RzXJ~t
T~s}Nx#
} yVS\Q,:J9
} FT/amCRyT
//负责部分文件的抓取 HC7JMj
**FileSplitterFetch.java U8O(;+
*/ zj%cQkZ
package NetFox; ]W) jmw'mo
\+Y!ILOI
m;/i<:`
import java.io.*; FFe)e>bH
import java.net.*; 9$O@`P\
\FifzKA
DJP6TFT&G
public class FileSplitterFetch extends Thread { Fe$/t(
@ls.&BHUP
:'*DMW~
String sURL; //File URL EXpSh}
long nStartPos; //File Snippet Start Position *^h_z;{,
long nEndPos; //File Snippet End Position K{b-TT 4
int nThreadID; //Thread's ID @GGccF
boolean bDownOver = false; //Downing is over Pp_V5,i\
boolean bStop = false; //Stop identical 9Nt3Z>d
FileAccessI fileAccessI = null; //File Access interface d 4O
;[6&0!N\
-&Gfh\_NW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hz)9"B\S
{ f\K#>u* Q
this.sURL = sURL; 2F?kjg,
this.nStartPos = nStart; n`L,]dco
this.nEndPos = nEnd; gb 4pN
nThreadID = id; nGrVw&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +t]Xj1Q
} 3s(Ia^
("Dv>&w9
ZBc|438[
public void run() z[&s5"
{ ]k+m=OR{/
while(nStartPos < nEndPos && !bStop) )saR0{e0N
{ Q$=*aUU%G
9?`RR/w
O9]\Q@M.
try{ xb$yu.c
URL url = new URL(sURL); yFM>T\@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OVswt
httpConnection.setRequestProperty("User-Agent","NetFox"); dZ2`{@AYY
String sProperty = "bytes="+nStartPos+"-"; 8$}OS-
httpConnection.setRequestProperty("RANGE",sProperty); Oif,|:
Utility.log(sProperty); Vxh.<b6&'
:oa9#c`L
Y<LNQ]8\G
InputStream input = httpConnection.getInputStream(); N z~"vi(t
//logResponseHead(httpConnection); AcC8)xRpk4
/f3m)pT
#`/QOTnm2c
byte[] b = new byte[1024]; @{}rG8
int nRead; 3jPB#%F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >oqZ !V5[
{ |}S1o0v{(a
nStartPos += fileAccessI.write(b,0,nRead); t26ij`V
//if(nThreadID == 1) ^ KH>1!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DQgH_!
} CLK^gZ
p4mY0Y]mP
e4.&aIC[
Utility.log("Thread " + nThreadID + " is over!"); 6 =gp:I
bDownOver = true; Do;#NLrWb
//nPos = fileAccessI.write (b,0,nRead); =nhzMU9c\y
} *Bw#c j
catch(Exception e){e.printStackTrace ();} U e*$&VlT
} {ZqQ!!b
} &!1}`4$[T
;KcFy@ 6q5
?`P2'i<b
//打印回应的头信息 K{L.ZH>7
public void logResponseHead(HttpURLConnection con) Z?1OdoT-
{ 6?SFNDQ"C
for(int i=1;;i++) g6euXI
{ v0 ];W|
String header=con.getHeaderFieldKey(i); oI@9}*
if(header!=null) -:]@HD:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); frH)_YJ%
Utility.log(header+" : "+con.getHeaderField(header)); !_^g8^>2(
else %f!iHo+Z
break; qrDcL>Hrn
} T[2}p=<%
} 3j*'HST
sh6(z?KP
bUvK
public void splitterStop() l)8sw=
{ 7/>a:02
bStop = true; abWl ut
} Sdc*rpH"(
Yx1 D)
`-O=>U5nH
} 2R`u[
?,% TU&Yn
zilaP)5x6
/* 4}-#mBV]/
**FileAccess.java wj%wp[KA$
*//文件访问(定位，写) -1W
package NetFox; yXF|Sqv
import java.io.*; &r@H(}$1\
!Zs,-=^D
afm_Rrg[
public class FileAccessI implements Serializable{ cU+>|'f&
d8:C3R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kZ[mM'u#
RandomAccessFile oSavedFile; ]^@0+!
long nPos; I,j3bC
>&hX&,hG
m2b`/JW
public FileAccessI() throws IOException u^=@DO'
{ jG8;]XP
this("",0); btQet.
} @^CG[:|
{!=2<-Aq
;3UvkN
public FileAccessI(String sName,long nPos) throws IOException uaxB -PZ
{ :qnokrGzB
oSavedFile = new RandomAccessFile(sName,"rw"); 1nB@zBQu-
this.nPos = nPos; sqG`"O4W
oSavedFile.seek(nPos); J@` 8(\(
} DHzkRCM
7;xKy'B\
q\H7&w
public synchronized int write(byte[] b,int nStart,int nLen) 1+^n!$
{ xG%*PNM0q
int n = -1; F+*Q <a4
try{ %6]\^
oSavedFile.write(b,nStart,nLen); 4oJ$dN
n = nLen; U**)H_S/~
} yW>RRE;
catch(IOException e) J3&Sj{ o
{ JS7dsO0;
e.printStackTrace (); (C\r&N
} *?N<S$m
<E}N=J'uJ
)ddsyFGW
return n; P6we(I`"2
} +*a7GttU
\7 Mq $d
~:Ixmqi}R
} q^6N+^}QN
oD,C<[(p
|EeBSRAfe
/* o7arxo\
**SiteInfoBean.java @dV9Dpu
*/ <[9?Rj@
package NetFox; (nz}J)T&
:c<*%*e
SG`)PW?
public class SiteInfoBean { #eLN1q&Z
OPiaG!3<
,s? dAy5
private String sSiteURL; //Site's URL Ff)@L-Y\K
private String sFilePath; //Saved File's Path P;c0L;/
private String sFileName; //Saved File's Name @g\;` #l
private int nSplitter; //Count of Splited Downloading File R&!]Rl9hf
+-P<CCvWz
i[_|%'p
public SiteInfoBean() o=mo/N4
{//nSplitter的缺省值为5 ai^t= s
//default value of nSplitter is 5 B^m!t7/,
this("","","",5); M[z3 f
} xgs@gw7!n0
%,;gP.dh7
97]4 :Zv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y?t2,cm
{ `EVg'?pl
sSiteURL= sURL; H9E(\)@
sFilePath = sPath; .qinR6=
sFileName = sName; pz @km
this.nSplitter = nSpiltter; C9pnU,[
N(BiOLZL6
j%5a+(H,z;
} x~Cz?ljbn
Um'Ro4
q_pmwJ:UL
public String getSSiteURL() mR,O0O}&
{ ]|y}\7Aa
return sSiteURL; k-vA#
} B{99gwMe]
6Ty3e|do
QES^^PQe:
public void setSSiteURL(String value) req-Q |
{ (GNEYf|
sSiteURL = value; L]*`4L
} R9r)C{63S&
Z:c*!`F
\*J.\f
public String getSFilePath() g@(4ujOT
{ ZR6&AiL(Bj
return sFilePath; %HVD^. V
} l# BZzJ?~
nj"m^PmWo3
_j>L4bT
public void setSFilePath(String value) h[,XemwX
{ Oc~VHT
sFilePath = value; H\d;QN9Q;
} kw#X]`c3
AbG&9=Ks
:fW.-^"VP
public String getSFileName() <k5`&X!+
{ S%{lJYwXt
return sFileName; UI_v3c3b
} <dS5|||
>'.[G:b
vuW-}fY;
public void setSFileName(String value) JeL~]F
{ 18rp; l{
sFileName = value; -`g J
} 2;h+;G
iAgOnk[
_E(x2BS?
public int getNSplitter() wE8]'o
{ ~Q0&P!k
return nSplitter; V4Qz*z%
} DEcGFRgN~
ILNXaJ'0a
5E0wn'
public void setNSplitter(int nCount) U(!?d ]en
{ _C5nApb
nSplitter = nCount; e]Puv)S>{8
} x?gQ\0S<
} m'c#uU
d#4Wj0x
L@+Z)# V
/* moe/cO5a9
**Utility.java N|o>%)R
*/ py=i!vb&Z%
package NetFox; xmOM<0T
1j+eD:d'
\:h0w;34O
public class Utility { Eh:yRJ_8
:Nkz,R?
&D^e<j}RQ
public Utility() Agz=8=S%
{ IE|,~M2
fmBkB8
>r~|1kQ.
} y=wdR|b
E~}[+X@
//线程睡眠 y%JF8R;n
public static void sleep(int nSecond) m+p4Mc%u
{ URk$}_39
try{ GG*BN<(>!
Thread.sleep(nSecond); u!M&;QL
} "7:u0p!
catch(Exception e) KjC[q
{ ["<5?!bU
e.printStackTrace (); X:DMT>5k
} @f\ X4!e*y
} :bI,rEW#_
" xlJs93c
//日志 7WXiG0
public static void log(String sMsg) (&k')ff9K
{ xS-w\vbLV
System.err.println(sMsg); b#e]1Q
} @PKAz&0
\6U 2-m'
1T:)Zv'
public static void log(int sMsg) ?l(nM+[kSL
{ z"9aAytd
System.err.println(sMsg); x4@MO|C
} Cy]"
} a$A2IkD
xJ$Rs/9C
haN"/C^
/* 7(H?k
**TestMethod.java y)0gJP L^
*/ <. ezw4ju
package NetFox; r!CA2iK`
$tEdBnf^ca
%s]U@Ku(a
public class TestMethod { dP?nP(l
*q+oeAYX
Ct-rD79l
public TestMethod() N!]PIWnC
{ ///xx/weblogic60b2_win.exe ,nI_8r"M>
try{ \A` gK\/h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t$tsWAmiA[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m9 ^m
SiteFileFetch fileFetch = new SiteFileFetch(bean); suzFcLxo
fileFetch.start(); =CWc`
} |{zHM23gD
catch(Exception e){e.printStackTrace ();} 5aa}FdUq
K3j_C`Se
"4KkKi
} X>3iYDe
Cm99?K
l# }As.o}
public static void main(String[] args) :PHUsy
{ `^?}s-H+
new TestMethod(); nZ"{y
} y?[5jL|Ue
} D1oaG0
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