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)); ]-s`#
} ]O9f"cj
for(int i=0;i<nEndPos.length-1;i++) Uwm[q+sTp
{ <T.3ZZ%
nEndPos = nStartPos[i+1]; h'YcNkM 2>
} RY/ Z~]
nEndPos[nEndPos.length-1] = nFileLength; AFm*60C
} @qhg[= @
} y1"^S
MTITIecw=
Mi/'4~0Y
//启动子线程 CQuvbAo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; milK3+N
for(int i=0;i<nStartPos.length;i++) S5pP"&I[
{ u,SX`6%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8DS5<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <T_Nlar^^
nStartPos,nEndPos,i); _8b>r1$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f?<M3P
fileSplitterFetch.start(); $E~Lu$|
} K[|P6J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `SS~=~WY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z#E,96R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NW>:Lz ?"
nEndPos = " + nFileLength); 08jUVHdt
// fileSplitterFetch[nPos.length-1].start(); K{w=qJBM
QsF<=b~
\FY De
//等待子线程结束 F=T.*-oS3
//int count = 0; eg~^wi
//是否结束while循环 pu)9"Ad[ G
boolean breakWhile = false; BK\~I
h}%M
MVL }[J
while(!bStop) {FmFu$z+[
{ u/:Sf*;?
write_nPos(); 53&xTcv}x
Utility.sleep(500); \utH*;J|x
breakWhile = true; dv9Pb5i
a5~C:EU0
.idl@%
for(int i=0;i<nStartPos.length;i++) 3{LvKe
{ +VW]%6+
if(!fileSplitterFetch.bDownOver) 2Ku#j ('
{ <sFf'W_3{
breakWhile = false; yExyx?j.
break; xY'YbHFz
} leYmVFE
} 1H[;7@o$e
if(breakWhile) QEHZ=Yg%3
break; vAhO!5]>\
Gc!{%x
eD1MP<>h
//count++; p|8Fl
//if(count>4) x w83K
// siteStop(); 7<Js'\Z
} |Gs-9+'y
J&Qy$itqg
{}C7VS1
System.err.println("文件下载结束！"); EkAqFcKLq
} yrYaKh
catch(Exception e){e.printStackTrace ();} ~t3?er& R
} ,H(vD,54g
RkV3_c
Sm_:SF!<D6
//获得文件长度 _,?HrL9
public long getFileSize() g(r'Y#U
{ \*"0wR;[K
int nFileLength = -1; >)Z2bCe
try{ 1'pQ,
URL url = new URL(siteInfoBean.getSSiteURL()); Cv7RCjMw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~HI0<;r=eL
httpConnection.setRequestProperty("User-Agent","NetFox"); s ;Nu2aOp7
5.HztNL
& ~G
int responseCode=httpConnection.getResponseCode(); XN%D`tbvJ
if(responseCode>=400) 3:Egqw
{ 61wG:
processErrorCode(responseCode); 128 rly
return -2; //-2 represent access is error m/B9)JzY
} GeTCN
+hhbp'%
e14Q\
String sHeader; I}0-
CMjPp`rA
][qA@3^Tw
for(int i=1;;i++) ?gP/XjToMg
{ |-Klh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \`9|~!,Ix7
//Utility.log(in.readLine()); { 3P!b|V>
sHeader=httpConnection.getHeaderFieldKey(i); 9JeGjkG,
if(sHeader!=null) *<5lx[:4/x
{ iZ;jn8
if(sHeader.equals("Content-Length")) sh3}0u+
{ Ec/+9H6g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'N/%SRk
break; JkEQ@x
} 8>+eGz|
} dM.Ow!j
else >Nqkz?67
break; @,$HqJ
} ky"7 ^
} m{Xf_rQ w
catch(IOException e){e.printStackTrace ();} 5d;K.O
catch(Exception e){e.printStackTrace ();} 4[j) $!l`
o%Q'<0d
cwU6}*_zn
Utility.log(nFileLength); r 24]2A
[o6<aE-
IN*Z__l8j`
return nFileLength; &1n0(qB
} ?Ir6*ZyY
B|w}z1.
$jL.TraV7
//保存下载信息（文件指针位置） L7="!I
private void write_nPos() !aoO,P#j
{ aq**w?l
try{ TK1MmL
output = new DataOutputStream(new FileOutputStream(tmpFile)); aa3YtNpP
output.writeInt(nStartPos.length); F&Z>B};
for(int i=0;i<nStartPos.length;i++) N.J:Qn`(
{ }z@hx@N/
// output.writeLong(nPos); TJa%zi
output.writeLong(fileSplitterFetch.nStartPos); z$,hdZ]
output.writeLong(fileSplitterFetch.nEndPos); :9>nY
} F<1'M#bl
output.close(); 05DtU!3O
} 7P(:!ce4-
catch(IOException e){e.printStackTrace ();} 1O{67Pf
catch(Exception e){e.printStackTrace ();} R|yTUGY
} HM x9M$
_J`M>W)8
'7%9Sqx
//读取保存的下载信息（文件指针位置） Jx,s.Z0@7,
private void read_nPos() S!bvU2d
{ p[IgnO
try{ e=C,`&sz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]vG)lY.=
int nCount = input.readInt(); ON^u|*kO
nStartPos = new long[nCount]; g:V6B/M&
nEndPos = new long[nCount]; R'_[RHFC
for(int i=0;i<nStartPos.length;i++) }zLE*b,
{ -#hl&^u$
nStartPos = input.readLong(); d@~)Wlje
nEndPos = input.readLong(); #-8/|_*
} +%^xz 1m
input.close(); EkPSG&6RZ
} Xp@OIn
catch(IOException e){e.printStackTrace ();} .- o,_eg1f
catch(Exception e){e.printStackTrace ();} E_#&L({|@
} q9Wtu7/
m{"zFD/
fe,CY5B{
private void processErrorCode(int nErrorCode) H$HhB8z3
{ !ym5'h
System.err.println("Error Code : " + nErrorCode); Z!6G(zz:>
} ~Y$1OA8
^^mi@&ApLD
_TiF}b!hi
//停止文件下载 n+w>Qz'
public void siteStop() "^7Uk#! 7
{ nfR5W~%*:
bStop = true; PI?[
for(int i=0;i<nStartPos.length;i++) pgarGaeq
fileSplitterFetch.splitterStop(); v\Gu
QUO?q+
epePx0N%x$
} 36z{TWF
} Sx7xb]3XI"
//负责部分文件的抓取 pQJZE7S
**FileSplitterFetch.java W@LR!EW)
*/ hHQt4 r'd
package NetFox; #=c%:{O{4R
\qPrY.-
e!yt<[ph
import java.io.*; 0Oq1ay^
import java.net.*; {0~ p"%*
# jyAq$I0
6C=.8eP
public class FileSplitterFetch extends Thread { Xb {y*',
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~5zhK:7c
String sURL; //File URL 4H)a7<,
long nStartPos; //File Snippet Start Position SqLKF<tY]/
long nEndPos; //File Snippet End Position [ CY=
int nThreadID; //Thread's ID j@f(cRAf#
boolean bDownOver = false; //Downing is over U/;Vge8{
boolean bStop = false; //Stop identical 1>LquZ+Kj
FileAccessI fileAccessI = null; //File Access interface 0!T $Ef
:/08}!_:
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p_D)=Ef|&
{ 0&|-wduR=
this.sURL = sURL; dcsd//E
this.nStartPos = nStart; 3FfS+q*3S
this.nEndPos = nEnd; p_( NLJ%
nThreadID = id; >jm9x1+C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qIl@,8T
} !`o=2b=N
"|H0 X#
7>TG ]&
public void run() NUseYU``
{ A.Njn(z?Lz
while(nStartPos < nEndPos && !bStop) c s>W6
{ nN:i{t4f
^B7Aam
)deuB5kz
try{ 2P*O^-zRp
URL url = new URL(sURL); Qoc-ZC"<6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TqC"lO>:Q
httpConnection.setRequestProperty("User-Agent","NetFox"); ;3_'{
String sProperty = "bytes="+nStartPos+"-"; !!AutkEg>
httpConnection.setRequestProperty("RANGE",sProperty); (<t)5?@%
Utility.log(sProperty); f#?R!pR
<cS1}"
oz QL2
InputStream input = httpConnection.getInputStream(); & |r)pl0$
//logResponseHead(httpConnection); ;NEHbLH#F
. Hw^Nx
-Cl0!}P4I
byte[] b = new byte[1024]; iD9GAe}x
int nRead; kE1u-EA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R[6&{&E:
{ !Wk "a7
nStartPos += fileAccessI.write(b,0,nRead); &F)lvtt|
//if(nThreadID == 1) *@< jJP4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *Co+UJjT
} -c. a7
b^1!_1c
_?8T'?-1
Utility.log("Thread " + nThreadID + " is over!"); o{/D:B
bDownOver = true; y_w4ei
//nPos = fileAccessI.write (b,0,nRead); 5E]I
} %NuS!v>
catch(Exception e){e.printStackTrace ();} MZ.Jkf(
} A-kI_&g\Og
} y~w$>7U.
%~@}wHMB
S&yCclM
//打印回应的头信息 YRl2e`&jt
public void logResponseHead(HttpURLConnection con) Xv6s,<#\
{ 2KU[Yd
for(int i=1;;i++) nX~sVG{Q
{ Y0DBkg
String header=con.getHeaderFieldKey(i); DY%E&Vd:h
if(header!=null) }Q*8QV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :%{8lanO
Utility.log(header+" : "+con.getHeaderField(header)); ;G?_^ 0
else Z^b1i`v
break; R lv|DED$
} S;= D/)[mr
} |&7l*j(\
dS-l2 $n
:`d& |BB
public void splitterStop() +=*ZH`qX
{ F2#^5s(
bStop = true; >R6Me*VR
} E/ Pa0.
{?82>q5F
|zSkQ_?54
} Wn|w~{d{
FQ_4a}UOjX
_d:l1jD
/* l+@NjZGm<
**FileAccess.java 3SDw-k
*//文件访问(定位，写) ]krOPM/
package NetFox; =6ojkTk
import java.io.*; zg|]Ic
2$|WXYY
s iC/k*
public class FileAccessI implements Serializable{ 9R!.U\sq
WVKzh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Pr" 2d\
RandomAccessFile oSavedFile; B?k75G
long nPos; dx|j,1e
kZeb^Q+,
v~j21`
public FileAccessI() throws IOException |]V0sgpoZ
{ \S _ycn
this("",0); Vg0Rc t
} "gYn$4|R7*
zXB.)4T
3(X"IoNQ
public FileAccessI(String sName,long nPos) throws IOException J 5~bs*a8
{ ">|fB&~A
oSavedFile = new RandomAccessFile(sName,"rw"); ?me0J3u_
this.nPos = nPos; Bc$t`PI
oSavedFile.seek(nPos); +Bgy@.a?
} ((#|>W\&
, j7&(V~
ZPHB$]ri
public synchronized int write(byte[] b,int nStart,int nLen) ><%z~s
{ )jvYJ9s
int n = -1; *?cE]U6;
try{ 0P z"[
oSavedFile.write(b,nStart,nLen); 2 g,UdG
n = nLen; yy@g=<okt\
} I;9>$?t[
catch(IOException e) cZi/bIh
{ ftRf~5d2
e.printStackTrace (); dG\dGSZ\h
} BTqY_9
!CUrpr/*
(k4>I"x)
return n; Q!WXFS
} J'W6NitMr
B\`4TU}kE
4vF1
} UH2fP G
rz5AIe>Hm
Cjdw@v0;
/* M"W-|t)~
**SiteInfoBean.java _DS_AW}D
*/ !{jDZ?z{h
package NetFox; !;>j(xc
Y<odXFIS
M, f6UYo=
public class SiteInfoBean { @-)jU!
#fd;]
bejvw?)S.
private String sSiteURL; //Site's URL _46 y
private String sFilePath; //Saved File's Path 3U^E<H
private String sFileName; //Saved File's Name Xf(H_&K
private int nSplitter; //Count of Splited Downloading File qf-0 | w
rZEL7{
Dn1aaN6
public SiteInfoBean() )ERmSWq/u
{//nSplitter的缺省值为5 _NA[g:DZ&O
//default value of nSplitter is 5 :+06M@
this("","","",5); [f 4Nq \i
} 7S|nn|\Kp
7b7@"Zw*
8Th{(J_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,t2Mur
{ yy8h8{=g
sSiteURL= sURL; ei%L[>N
sFilePath = sPath; bLuAe EA
sFileName = sName; WKek^TW4HE
this.nSplitter = nSpiltter; >UlAae44
/x\{cHAt8J
UDl[
} ^VabXGzo#
cgY+xd@
-*HR0:H
public String getSSiteURL() /{il;/Vj
{ dz_~_|
return sSiteURL; H}vq2|MN
} SA!P:Q?h
()%NotN;
;&=c@>!xP#
public void setSSiteURL(String value) vuN!7*d+
{ :Aq==N_/2
sSiteURL = value; 4E:kDl*@
} NpqK+GO
hUR>NUK@8
_!_%Afz
public String getSFilePath() apmZ&Ab
{ +9yV'd>U
return sFilePath; v@n0ma=
} {5`=){
DNwqi"
@,kR<1
public void setSFilePath(String value) )/Z% HBn
{ PLoD^3uG)
sFilePath = value; ]fiAV|'^
} jxeZ,w o
*e/8uFX
9\f%+?p
public String getSFileName() pT ]:TRPS
{ 'Sk-L 5
return sFileName; _e4%<!1
} ( &N`N1
q#pD}Xe$
#u]'3en
public void setSFileName(String value) 3pU/Zbb,:
{ {&3{_Ml
sFileName = value; S1SsJo2\
} 5|:t$
4 s&9A/&pC
(58}G2}q
public int getNSplitter() $<DcbJW
{ m6wrG`-di
return nSplitter; {@E(p4W
} ^&8FwV]
>tGl7Ov
&-R(u}m-F
public void setNSplitter(int nCount) 1>)q5D
{ 7j,u&%om
nSplitter = nCount; 7^bde<0
} J)I|Xot
} R-[t4BHn
L@VIC|~E
3]MSS\uB
/* ']Z1nb
**Utility.java Cr&,*lUo
*/ =pa F6!AB
package NetFox; R%EpF'[~[
y*oH"]D
Ng,<4;
public class Utility { qL;u59
K (px-jY
4arqlzlo
public Utility() 5oOF|IYi
{ I l2`c}9
iCXKi7
RvXK?mL4F
} vHmsS\\~9
nGoQwKIW
//线程睡眠 K3*8-Be
public static void sleep(int nSecond) )y#~eYn
{ ~[[(_C3
try{ )\3 RR.p
Thread.sleep(nSecond); J>w3>8!>7
} `2I<V7SF$
catch(Exception e) Z)qts=
{ 9jkaEn>m^
e.printStackTrace (); =sFLzAu8
} (6g;FD:"6
} f5tkv<) %
F4X0DRC,G
//日志 _DD.#YB</
public static void log(String sMsg) G?$0OU
{ EEI!pi
System.err.println(sMsg); SSrYFu"
} 8n2MZ9p]
0pW?v:!H
HzdyfZ!jR
public static void log(int sMsg) qvHRP@
{ Bj1{=Pvl
System.err.println(sMsg); jT:z#B%
} + 7~u_J
} /$-Tg)o5i
31*0b|Z
.$]%gjIBCl
/* I 7 B$X=
**TestMethod.java xtq='s8e
*/ t^')ST
package NetFox; !Zi_4 .(4
Z]^Ooy[pb
UB9n7L(@c
public class TestMethod { Ms61FmA4
ZvVrbj&
JlMD_pA
public TestMethod() -F338J+J24
{ ///xx/weblogic60b2_win.exe OL0W'C9oA
try{ ibj3i7G?
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); S`t@L}
SiteFileFetch fileFetch = new SiteFileFetch(bean); =" Sb>_
fileFetch.start(); /9wmc2
} 0Z,a3)jcc
catch(Exception e){e.printStackTrace ();} )}|b6{{<
vw5f|Q92
l =`?Im
} tgpg
&ZR}Z7E*=
V'Z Z4og
public static void main(String[] args) uW{;@ 7N
{ 9\J6G8b>|I
new TestMethod(); @o/126(k
} L0QF(:F5
} [+8in\T i
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