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)); xsTxc&0^
} As\5Ze9|
for(int i=0;i<nEndPos.length-1;i++) AO]lXa
{ ~Afs
nEndPos = nStartPos[i+1]; 3>(`Y
} ^KaMi_--
nEndPos[nEndPos.length-1] = nFileLength; Orb(xLChJ
} kp6x6%{K\
} K$]QzPXS
zh.c_>jS
IW1\vfe
//启动子线程 QVH_B+ Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ck:J
for(int i=0;i<nStartPos.length;i++) < 5PeI
{ )aC+qhh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i3"sArP"|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "_K 6=
nStartPos,nEndPos,i); /iN\)y#u1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sXa8(xc
fileSplitterFetch.start(); 64vSJx>u
} yTn@p(J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8$vH&HdI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C5M-MZaS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H<xC%/8
nEndPos = " + nFileLength); %OtW\T=u
// fileSplitterFetch[nPos.length-1].start(); =z/F=1^<
D1n2Z:9
KwHOV$lD;
//等待子线程结束 $G_<YVXcG
//int count = 0; PGKXzp'
//是否结束while循环 1A)~Y
boolean breakWhile = false; GVM#Xl}w9
5ZcnZlOOQ
2o$8CR;
while(!bStop) (lnQ!4LK
{ gQEV;hCO
write_nPos(); Ueeay^zN
Utility.sleep(500); J50 ~B3bj`
breakWhile = true; %_[-[t3
9y5\4&v
]xG8vy
for(int i=0;i<nStartPos.length;i++) <e^/hR4O
{ DPwSg\*)
if(!fileSplitterFetch.bDownOver) KR}0(,Y
{ 'O`3FI
breakWhile = false; $Y`aS^IW
break; U.aa iX7
} o.5j@dr
} Tpukz_F
if(breakWhile) yd72y'zi
break; Wj:QC<5 v
ie(7m|.
(<l2 ^H
//count++; #$w#"Nr9k
//if(count>4) ?lK!OyCkc
// siteStop(); 3ngLEWT
} sb @hGS
lnDDFsA
s=TjM?)
System.err.println("文件下载结束！"); 4I-p/&Q
} //Gvk|O1
catch(Exception e){e.printStackTrace ();} 5u46Vl{
} qX(%Wn;n
gQuw|u
L0kNt &di
//获得文件长度 vb- .^l
public long getFileSize() '-IT@}
{ r?!xL\C\
int nFileLength = -1; J,O@T)S@
try{ j/<y
URL url = new URL(siteInfoBean.getSSiteURL()); J31M:<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tA-B3 ]
httpConnection.setRequestProperty("User-Agent","NetFox"); mx9/K+:
7LwS =yP
pQ 6#L
int responseCode=httpConnection.getResponseCode(); f~FehN7
if(responseCode>=400) U!/nD~A
{ b8.%?_?
processErrorCode(responseCode); YfwJBzD
return -2; //-2 represent access is error 0s|LK
} Qs9U&*L
rk/ c
EYxRw
String sHeader; 5}xni
pq3 A%|
wzPw;xuG
for(int i=1;;i++) igrog
{ X|`,AKJit
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~n^G<iXLp
//Utility.log(in.readLine()); 0f%:OU5Y
sHeader=httpConnection.getHeaderFieldKey(i); ;_/q>DR>,3
if(sHeader!=null) X-1Vp_(,TP
{ ;q; C^l
if(sHeader.equals("Content-Length")) Zd U{`>v
{ 1Wk EPj,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K$cIVsfr
break; 1=Zw=ufqV
} \Byk`} 9
} ?=!XhU .
else aNC,ccm
break; 0l:pWc
} ph?0I:eU
} huJq#5?
catch(IOException e){e.printStackTrace ();} Sz|CreFK16
catch(Exception e){e.printStackTrace ();} g&3#22z
uq4sbkP
dB+GTq=6f
Utility.log(nFileLength); %Z[/U
\TB%N1^
SMO%sZ]
return nFileLength; wDSUMB<?
} B21AcE
;3|Lw<D5;
OgN1{vRFx
//保存下载信息（文件指针位置） )H9*NB8%
private void write_nPos() (oitCIV
{ 18"VB50b}
try{ Z'NbHwW}
output = new DataOutputStream(new FileOutputStream(tmpFile)); D}/=\J/
output.writeInt(nStartPos.length); r!$NZ2I
for(int i=0;i<nStartPos.length;i++) mBZDl4 '
{ cNo4UZvr
// output.writeLong(nPos); Ccr+SR2
output.writeLong(fileSplitterFetch.nStartPos); oPu|Q^I=
output.writeLong(fileSplitterFetch.nEndPos); 5o| !f
} wUCDJY:,1
output.close(); :"P hkR
} 7ml0
catch(IOException e){e.printStackTrace ();} 4A/,X>W61
catch(Exception e){e.printStackTrace ();} };m7FO
} !""!sFx)R
Z;y}gv/{
As'M39*V
//读取保存的下载信息（文件指针位置） 3{4/7DcX
private void read_nPos() ]Ec[")"kT
{ I0HY#z%
try{ '<D`:srV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); to!W={S<ol
int nCount = input.readInt(); @`;Y/',
nStartPos = new long[nCount]; W B*`zCM
nEndPos = new long[nCount]; 5Ue^>8-
for(int i=0;i<nStartPos.length;i++) v^],loi<V
{ <`xRqe:&9
nStartPos = input.readLong(); Cre0e$ a
nEndPos = input.readLong(); mU+FQX
} oiv2rOFu
input.close(); tM$0 >E
} {?f^
catch(IOException e){e.printStackTrace ();} 6l\UNG7
catch(Exception e){e.printStackTrace ();} lDJd#U'V
} a^XTW7]r
# 5f|1O
sL7`=a.&T
private void processErrorCode(int nErrorCode) BY4 R@)
{ ]tQDk4&i
System.err.println("Error Code : " + nErrorCode); 6I cM:x
} V1`5D7Z
'hlB;z|T
c_G-R+
//停止文件下载 bN4&\d*u#
public void siteStop() KBr5bcm4u
{ Wt+y-ES
bStop = true; LA+$_U"Jk
for(int i=0;i<nStartPos.length;i++) 6PJJ?}P^1
fileSplitterFetch.splitterStop(); "_1-IE
5{ 4"JO3
$uUb$8Bu
} {"0TO|%x
} B)DC,+@$
//负责部分文件的抓取 Jl>at
**FileSplitterFetch.java F/h:&B:;
*/ )pS_+ZF
package NetFox; V"7<[u]K|
< R|)5/9
GIC"-l1\
import java.io.*; 2-6.r_
import java.net.*; [^U;
xV,4U/T
c#n4zdQd]5
public class FileSplitterFetch extends Thread { Y*kh$E%<#
qXU:A-IdIl
Pv7f _hw
String sURL; //File URL -yl4tW
long nStartPos; //File Snippet Start Position 3%[)!zKv
long nEndPos; //File Snippet End Position ^/%o%J&Hz
int nThreadID; //Thread's ID 17i<4f#
boolean bDownOver = false; //Downing is over z<oE!1St
boolean bStop = false; //Stop identical TRk ?8
FileAccessI fileAccessI = null; //File Access interface {(M&-~Yh
Lz9$,Y[
o0aO0Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *X=@yB*aK
{ 5DkK'tCI9Z
this.sURL = sURL; )4!CR/ao
this.nStartPos = nStart; 0H OoKh
this.nEndPos = nEnd; lTV@b&
nThreadID = id; o5=)~D{/G3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4T==A#Z
} uG=t?C6
sd]54&3A
3^02fy
public void run() &?/N}g@K
{ +QIGR'3u
while(nStartPos < nEndPos && !bStop) ,#E3,bu6_4
{ mh A~eJ
{WYu0J@
d`?U!?Si
try{ YW?7*go'Z
URL url = new URL(sURL); `W"a!,s2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K2x6R
httpConnection.setRequestProperty("User-Agent","NetFox"); J.bFv/R
String sProperty = "bytes="+nStartPos+"-"; 0<]$v"`I
httpConnection.setRequestProperty("RANGE",sProperty); 7m|`tjQ1
Utility.log(sProperty); @4/~~
zj~nnfoys
fqcU5l[v,
InputStream input = httpConnection.getInputStream(); !paN`Fz\a
//logResponseHead(httpConnection); 9?u9wuH
i"%JFj_G
%uGleY]~
byte[] b = new byte[1024]; wO^$!zB W
int nRead; z'?7]C2b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :LZ-da"QR
{ saGRP}7?
nStartPos += fileAccessI.write(b,0,nRead); -TzI>Fz
//if(nThreadID == 1) 0kU3my]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DO7-=74=
} G0I~&?nDa
TJHN/Z/
a&$Zpf!!
Utility.log("Thread " + nThreadID + " is over!"); =@xN(](
bDownOver = true; h^o+E2<]
//nPos = fileAccessI.write (b,0,nRead); &K5C=]4
} uSABh^
catch(Exception e){e.printStackTrace ();} DC?21[60
} /^++As0pY
} l;XU#6{
$Cz1C
TqS2!/jp
//打印回应的头信息 &u+yM D
public void logResponseHead(HttpURLConnection con) 0M$#95n
{ 2wB.S_4"-<
for(int i=1;;i++) RDUT3H6~
{ e1^fUOS
String header=con.getHeaderFieldKey(i); E:08%4O
if(header!=null) ad"'O]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vC)"*wYB{
Utility.log(header+" : "+con.getHeaderField(header)); X}zX`]:I'
else Pv< QjY
break; M0cd-Dn
} TA Ftcs:
} G;2R]H#p
-Nsk}Rnk*
siZr@g!L
public void splitterStop() C-Nuy1o
{ SV$nyV
bStop = true; TRF]i/Bs
} \bU`
Qo'yS"g<9)
f'1(y\_fb
} c*N50%=4
Iq)(UfaSve
ctp?y
/* rpUy$qrRc
**FileAccess.java mbF(tSy
*//文件访问(定位，写) rei 8LW
package NetFox; n4^~gT%b5]
import java.io.*; L<bYRGz
J"diFz+20
ec`bz "1
public class FileAccessI implements Serializable{ *R5`.j =
?Fce!J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RTK}mhnV
RandomAccessFile oSavedFile; J5O.*&
long nPos; ID)^vwn
gh TcB
qv *3A?uzr
public FileAccessI() throws IOException 24//21m
{ XAkK:}h
this("",0); wAw42{M
} F;#zN
haCKv
92ZWU2"
public FileAccessI(String sName,long nPos) throws IOException Ffnk1/Zy
{ OFL|RLiD
oSavedFile = new RandomAccessFile(sName,"rw"); -^yXLa;D
this.nPos = nPos; kB8 Mi
oSavedFile.seek(nPos); N*Yy&[
} 2R~6<W+&:>
ndr)3tuYu
s8^~NX(xdy
public synchronized int write(byte[] b,int nStart,int nLen) 88 {1mA,v
{ fO6[!M(
int n = -1; xPt*CB
try{ 7skljw(
oSavedFile.write(b,nStart,nLen); ZT6V/MD7T.
n = nLen; 0x\2#i
} 7!pLK&_
catch(IOException e) (qUK7$
{ cQX:%Ix=
e.printStackTrace (); )u0O_R
} {&-#s#&
YJd8l>mz
f27)v(EJ
return n; k=?^){[We
} Jn=42Q:>
mwIk^Sz]@
TtPr)F|
} #:#Dz.$L
6a*83G,k
RwW$O@0
/* J@QdieW6
**SiteInfoBean.java vs+QbI6>-
*/ -j&Vtr
package NetFox; .Rvf/-e
}S*/b1
ZZ("-#?
public class SiteInfoBean { &iNS?1a%f=
fz3lR2~G
{(}yG_Q]!
private String sSiteURL; //Site's URL *hF^fxLbl
private String sFilePath; //Saved File's Path =p q:m
private String sFileName; //Saved File's Name T6uMFD4 |
private int nSplitter; //Count of Splited Downloading File !{(ls<
^LVk5l)\>g
Umz05*
public SiteInfoBean() y@3Q;~l,
{//nSplitter的缺省值为5 ePEe?o4;
//default value of nSplitter is 5 :m Kxa
this("","","",5); Me,<\rQ
} !MoOKW
Yl~$V(
"]#'QuR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M\9F:.t=
{ cvfUyp;P
sSiteURL= sURL; IE;\7r+h
sFilePath = sPath; Qs l80~n_7
sFileName = sName; |n`PESf_
this.nSplitter = nSpiltter; 8}BS2C%P
2bLI%gg3
r+S;B[Vd
} @}DFp`~5|
WL U}
PO o%^'(
public String getSSiteURL() rP'AJDuq
{ O9^T3~x[V
return sSiteURL; "Zcu[2,
} 1`JB)9P
3+(z_!Qh
?YBaO,G9o
public void setSSiteURL(String value) ]g,lRG
{ J\=a gQ
sSiteURL = value; Xwq]f:@V
} j;\[pg MR/
d>|;f
q@l(Qol
public String getSFilePath() m[:K"lZ ]2
{ ]-:6T0JuS
return sFilePath; w2OsLi Sv
} G;s"h%Xw98
NiA4JgM]v
Vb!O8xV4;+
public void setSFilePath(String value) c-B/~&
{ R0wf#%97
sFilePath = value; aQUGNa0+d
} {DwIjy31T
m#\[m<F
,Dp0fauJ
public String getSFileName() !9]d|8!
{ ,lm=M5b
return sFileName; 9S>g6}[E#0
} +sf .PSz$
!^WHZv4
S^N{wZo
public void setSFileName(String value) zvO:"w}
{ P:k+ y$
sFileName = value; <a|@t@R
} 8lP6-VA
^DB{qU
{@.Vh]
public int getNSplitter() G1d(,4Xp
{ bL1m'^r
return nSplitter; |cd-!iJX-
} F!yV8XQ
A@$kLex
Y#HI;Y^RP
public void setNSplitter(int nCount) #xT!E:W'
{ }x:f%Z5h
nSplitter = nCount; gXy-Mpzp
} Ef@,hX
} Ck'aHe22'
cb$-6ZE/
& mt)d
/* vt1lR5
**Utility.java !{Z~<Ky
*/ LFf`K)q
package NetFox; QyGnDomQ
<9eu1^g
zT#`qCbT'J
public class Utility { :]WqfR)#
Zu/<NC (
+Qj(B@i
public Utility() $,27pkwHeW
{ f.6~x$:)`E
rs-,0'z,7
)T|L,Lp
} Y)|N"f;
.`p&ATgv
//线程睡眠 [L(hG a
public static void sleep(int nSecond) 7%;_kFRV
{ 9P WY52!
try{ gfgn68k
Thread.sleep(nSecond); cWLqU
} A''pS
catch(Exception e) MX|H}+\
{ 9Q.#\
e.printStackTrace (); 'V&Y[7Aeq
} 09h.1/
} ST dNM\+
~Z)/RT/
//日志 GTl xq%?b
public static void log(String sMsg) !{%&=tIZ
{ !3qVB
System.err.println(sMsg); =#xK=pRy;
} e0HfP v_
QLKK.]
HM9fjl[
public static void log(int sMsg) ej(ikj~j
{ ~E5z"o6$
System.err.println(sMsg); D Ml?o:l
} >m6&bfy\q
} y 1\'(1
& E}mX]t
=^;P#kX
/* `[fxyg:u
**TestMethod.java 7h9U{4r: M
*/ BS1Ap
package NetFox; B.dT)@Lx0
('[TLHP
kHK0(bYK
public class TestMethod { </`yd2>
7'lZg<z{~j
^Q}eatEn
public TestMethod() #UP~iHbt\
{ ///xx/weblogic60b2_win.exe Ond'R'3\E
try{ WT\<.Py
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YN/}9.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7^6uG6
SiteFileFetch fileFetch = new SiteFileFetch(bean); fS&6
fileFetch.start(); X[yNFW}S2W
} na+d;h*~y
catch(Exception e){e.printStackTrace ();} 9i q""
#]Y>KX2HG
mN_Z7n;^eh
} c3TKl/
G&f8n
4Y\wnwI
public static void main(String[] args) k@mVxnC
{ 4=8QZf0\
new TestMethod(); \;X+X,M
} 5\fCd|
} zg)sd1@
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