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)); rMIr&T
} y*A#}b*0
for(int i=0;i<nEndPos.length-1;i++) ab8uY.j
{ {"l_x]q
nEndPos = nStartPos[i+1]; ALS\}_8
} Dk4Jg++
nEndPos[nEndPos.length-1] = nFileLength; 2%"2~d7
} Y<M,/Y_ !
} <@xp. Y
1a4HThDXP
BuMBnbT
//启动子线程 UA$ XjP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; preKg$U
for(int i=0;i<nStartPos.length;i++) wvsKnYKX
{ tjc3;9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :U!knb"/>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mw%do&e
nStartPos,nEndPos,i); k"F5'Od
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h}fz`ti U
fileSplitterFetch.start(); cmF&1o3_
} !a?$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9X&Xc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :iJ+ImBpK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bI.LE/yk
nEndPos = " + nFileLength); BYuF$[3ya&
// fileSplitterFetch[nPos.length-1].start(); 2iHD$tw
'EoJo9p6}
d;O16xcM/
//等待子线程结束 XB, 2+
//int count = 0; |Fz/9+I
//是否结束while循环 ]TQ2PVN2
boolean breakWhile = false; Sc'z vlq
Xh"JyDTj3
cjfYE]
while(!bStop) _MQ)
{ NNSHA'F,.\
write_nPos(); c}GmS@
Utility.sleep(500); "&*O7cs$pA
breakWhile = true; V(Ll]g/T_;
h^R EBPe
=TKu2
for(int i=0;i<nStartPos.length;i++) bb}zn'xC
{ ek!x:G$'
if(!fileSplitterFetch.bDownOver) %PozxF:
{ :N$^x /{
breakWhile = false; 9x@( K|
break; xtWQ.
} sy`@q<h(
} 7(cRm$)L
if(breakWhile) vAWJP_;J
break; #DK@&Gv
Hx[YHu KL^
E~vM$$O$
//count++; dbM~41C6
//if(count>4) A;ip V :)
// siteStop(); 8~*<s5H
} I/YBL
SSG57N-T
W^j;"qj
System.err.println("文件下载结束！"); iF]G$@rbU
} A^lJlr:_`
catch(Exception e){e.printStackTrace ();} Ws;S=|9,7~
} 9N1Uv,OtB
t&scvXh
r'bctFsD
//获得文件长度 =iJfz
public long getFileSize() dH]0(aJ
{ O^|:q
int nFileLength = -1; HURrk~[
try{ Dp1FX"a)
URL url = new URL(siteInfoBean.getSSiteURL()); ])`+ 78
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w:[1,rRvT
httpConnection.setRequestProperty("User-Agent","NetFox"); Qm9r>m6p@N
,uz+/K%OA5
Ot,_=PP
int responseCode=httpConnection.getResponseCode(); R<\5q%@G
if(responseCode>=400) Nf@-i`
{ (]cM;
processErrorCode(responseCode); ,_SE!iL
return -2; //-2 represent access is error 0 0JH*I
} kT7x !7C
v67utISNI
%K9pnq/T^
String sHeader; 1=U(ZX+u
*\gS 2[S
+=_^4
for(int i=1;;i++) |A .U~P):
{ ajr);xd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UQX.
//Utility.log(in.readLine()); <H; z4
sHeader=httpConnection.getHeaderFieldKey(i); RC[mpR;2
if(sHeader!=null) /Kw}R5l
{ dWR-}>
if(sHeader.equals("Content-Length")) m=m T`EP
{ eT!*_.' e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j<*
break; a9f!f %9
} Q4;%[7LU
} N<d0C
else Xl/SDm_p
break; \OzPDN
} ~]w|ULNa3|
} XJ$mRh0`K
catch(IOException e){e.printStackTrace ();} P0mY/bBU
catch(Exception e){e.printStackTrace ();} l_q=@y
G5l?c@o
fen~k#|l
Utility.log(nFileLength); o[A y2"e?
d*B^pDf
e>zv+9'Q
return nFileLength; ^CBc~um2
} B2kKEMdGg
/#FU"
K|Cb6''
//保存下载信息（文件指针位置） uY_vX\;67z
private void write_nPos() 7]8nW!h;
{ ^ UDNp.6k
try{ sC}p_'L
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4Ou5Vp&y
output.writeInt(nStartPos.length); ,N1I\f
for(int i=0;i<nStartPos.length;i++) W5SCm(QS5
{ m)q e
// output.writeLong(nPos); #Fwf]{J
output.writeLong(fileSplitterFetch.nStartPos); nOQvBc
output.writeLong(fileSplitterFetch.nEndPos); 2zPO3xL,
} 2?}5U)Hg
output.close(); F,.dC&B
} AE@N:a
catch(IOException e){e.printStackTrace ();} US'rhSV
catch(Exception e){e.printStackTrace ();} S|Yz5)*
} /\wm/Yx?S
Z(|'zAb^
oro^'#ki
//读取保存的下载信息（文件指针位置） x-@}x@n&[
private void read_nPos() -}G>{5.A
{ 6>d0i S@R
try{ isR)^fI|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O/ih9,
int nCount = input.readInt(); ?.~hex#M@
nStartPos = new long[nCount]; N3m~nEj
nEndPos = new long[nCount]; 5faY{;8
for(int i=0;i<nStartPos.length;i++) )OE!vA
{ x!`~+f.6
nStartPos = input.readLong(); sMDHg
nEndPos = input.readLong(); rk)h_zN
} -RBH5+SS2
input.close(); Ap)pOD7
} x&d:V
catch(IOException e){e.printStackTrace ();} I=c}6
catch(Exception e){e.printStackTrace ();} G|+naZ
} qgkC)
\2OjIEQQ
(&@,ZI;
private void processErrorCode(int nErrorCode) #,jw! HO]
{ nJr:U2d
System.err.println("Error Code : " + nErrorCode); 7blo<|9
} e"^n^_9
l}&&f8n
gbr-C
//停止文件下载 $/|2d4O:{
public void siteStop() q'CtfmI`r=
{ bo_Tp~j
bStop = true; Scz/2vNi`
for(int i=0;i<nStartPos.length;i++) H^JwaF
fileSplitterFetch.splitterStop(); D"ecwx{%;C
T(q/$p&q
i7|sVz=
} ZB'ms[
} rZkl0Y;n\
//负责部分文件的抓取 2&KM&NX~
**FileSplitterFetch.java qt,;Yxx#^
*/ g'<ekY+V:
package NetFox; m5kt O^EU
)^[PW&=W|x
r NT>{
import java.io.*; 5o2vj8::
import java.net.*; |N+uEiJ
x!;;;iS
!v?WyGbUg
public class FileSplitterFetch extends Thread { P{[@t_
rpMjDjW
M0Vs9K=
String sURL; //File URL x>eV$UJ
long nStartPos; //File Snippet Start Position i_ z4;%#?
long nEndPos; //File Snippet End Position ZO\x|E!b
int nThreadID; //Thread's ID bPHtP\)
boolean bDownOver = false; //Downing is over V)#rP?Y
boolean bStop = false; //Stop identical HWOOw&^<
FileAccessI fileAccessI = null; //File Access interface Vm]u-R`{
i=aK ?^+
L)-1( e<x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WLA LXJ7
{ zOsk'ZE&
this.sURL = sURL; M)Z3q
this.nStartPos = nStart; Msl8o c
this.nEndPos = nEnd; 1b`WzoJgH
nThreadID = id; o@W:PmKW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 j5~nLo2
} kCvf-;b
CCp&+LRvR
>Q% FW
public void run() *z6m644H
{ 1 TA\6a}
while(nStartPos < nEndPos && !bStop) TM<;Nj[*n
{ ,l7',@6Y
/& wA$h
C{2y*sx
try{ 6hAMk<kx?i
URL url = new URL(sURL); 2{I+H'w8:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %h"%G=:
httpConnection.setRequestProperty("User-Agent","NetFox"); ObEp0-^?
String sProperty = "bytes="+nStartPos+"-"; Ot([5/K
httpConnection.setRequestProperty("RANGE",sProperty); *wu|(t_ A
Utility.log(sProperty); =5u;\b>*
M.0N`NmS
vR?E'K3
InputStream input = httpConnection.getInputStream(); SJ).L.Cm6
//logResponseHead(httpConnection); ^;mnP=`l[
+hUz/G+3
y7/=-~
byte[] b = new byte[1024]; yR4++yk
int nRead; >v1ajI>O&{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4)+L(KyB2
{ KvkU]s_
nStartPos += fileAccessI.write(b,0,nRead); YW'l),Z
//if(nThreadID == 1) }e0>Uk`[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r(DW,xoK0
} 7]lUPLsl
i f!
GRj#1OqL
Utility.log("Thread " + nThreadID + " is over!"); 4M*!'sG\
bDownOver = true; ve@E.`
//nPos = fileAccessI.write (b,0,nRead); EJaGz\\
} DA9f\q
catch(Exception e){e.printStackTrace ();} {^_K
} Bl/Z _@
} ]=?.LMjnH
/j;HM[
h}yfL@
//打印回应的头信息 #kRt\Fzq
public void logResponseHead(HttpURLConnection con) U]64HuL
{ -Gd@baV
for(int i=1;;i++) a}5/?/
{ bo40s9"-*W
String header=con.getHeaderFieldKey(i); *r].EBJ\
if(header!=null) 0q_?<v_1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /[,0,B9!3
Utility.log(header+" : "+con.getHeaderField(header)); B(,j*,f
else `=19iAp.
break; 33OkYC%e
} %hN7K
} }-T :
8<PQ31
UIK4]cYC'
public void splitterStop() JV@b(x`
{ 3B?7h/f
bStop = true; \VHRI<$+5
} ^\7GFpc
z4wG]]Kh*
\JBPZ~N3
} m e2$ R>@
Eu`K2_b
~As_O6JI
/* PXo^SHJ+gt
**FileAccess.java L^e%oQ>s
*//文件访问(定位，写) sPRo=LB
package NetFox; 5;X3{$y
import java.io.*; 2aJ_[3p/h]
5~{s-Ms
sDP8!
public class FileAccessI implements Serializable{ ]+d>;$O
g96]>]A<{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9@wmngvM*Y
RandomAccessFile oSavedFile; q*7:L
long nPos; k FCdGl
y;=/S?L.:
%6E:SI4
public FileAccessI() throws IOException MQq!<?/
{ :ioD*k
this("",0); Vu;z|L
} d/lV+yZ
:|\)=4
_bSn YhS
public FileAccessI(String sName,long nPos) throws IOException WP >VQZ&
{ bFsJqA.A
oSavedFile = new RandomAccessFile(sName,"rw"); {~EPP .
this.nPos = nPos; iyP0;$
oSavedFile.seek(nPos); Xk}\-&C7
} Ue(\-b\)
zXML<?w
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public synchronized int write(byte[] b,int nStart,int nLen) tC\(H=ecP
{ 3 uJ?;
int n = -1; ?xw0kXK4
try{ oa6&?4K?F
oSavedFile.write(b,nStart,nLen); ^1;Eq>u
n = nLen; aRcVoOq
} k:#u%Z
catch(IOException e) ahg]OWn#
{ Bb.U4#
e.printStackTrace (); sF~!qag4q'
} V z-]H]MW,
J }|6m9k!
4P^CqD&i
return n; nJY3 1(p
} |f2bb
M=Y['wx
Kon|TeC>d
} i!yE#zew
=)nJ'}x
YRu#JYti
/* ]|_+lik#
**SiteInfoBean.java W{fNZb'
*/ .1jeD.l
package NetFox; Wv]ODEd
3f(tb%pa5
;lf$)3%[
public class SiteInfoBean { :ka^ztXG
SLda>I(p7&
mX[J15
private String sSiteURL; //Site's URL ]E^)d|_
private String sFilePath; //Saved File's Path WJy\{YAG
private String sFileName; //Saved File's Name s&1}^'|
private int nSplitter; //Count of Splited Downloading File ! =*k+gpF
=s&ycc;-5}
%Ot*k%F
public SiteInfoBean() UmG|_7
{//nSplitter的缺省值为5 U\-=|gQ'
//default value of nSplitter is 5 <[?ZpG
this("","","",5); rp=Y }
} }WHq?
fWyXy%Qq
ydMSL25<+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q^h/64F
{ dUv(Pu(.#
sSiteURL= sURL; $E}N`B7
sFilePath = sPath; r?/!VO-*N
sFileName = sName; Sl'{rol'
this.nSplitter = nSpiltter; 4+MaV<!tU^
slaH2}$xR
\-8aTF
} 3~?m?vj|Y
OR}+)n{
b4Pa5w
public String getSSiteURL() "[0.a\ d<
{ B+MnT{
return sSiteURL; :QC |N@C
} Hyi'z1
y-{?0mLq
a%5/Oc[[
public void setSSiteURL(String value) 7"1]5\p^g
{ tVh"C%Vkr
sSiteURL = value; Nh\o39=
} ;vy<!@Y;8
,c&gw tdl
-d^'-s
public String getSFilePath() y9.?5#aL
{ "28zLo3
return sFilePath; / }*}r
} UG[r /w5(F
}}Z2@}
Ss_}@p ^
public void setSFilePath(String value) yCN?kHG
{ mtdy@=?1Y
sFilePath = value; ,T$ GOjt
} XlnSh<e
PkLNIp1
3gnO)"$
public String getSFileName() >GLoeCRNu
{ )j\_*SoH
return sFileName; ,RW`9+gx
} %0 i)l|
_EJPI
x=+>J$~Pb
public void setSFileName(String value) J5';Hb)
{ aNA]hl
sFileName = value; 9Q!Z9n"8~)
} H \'1.8g/
bwj{5-FU
BMdZd5!p&
public int getNSplitter() (=%0$(S>
{ BC\W`K
return nSplitter; lQBEq"7$
} tP"6H-)X&
T]nAz<l),
Sc/$2gSG
public void setNSplitter(int nCount) H5V>d
{ jU* D
nSplitter = nCount; *ra>Kl0
} cpALs1j:
} IvlfX`("
<i]0EE}%
w%8y5v5
/* 0{vH.b @
**Utility.java ' QMcQvU
*/ Pq8oK'z-
package NetFox; O5Z9`_9<
C*3St`2@9
bX,#z,
public class Utility { :8hI3]9
r-TrA$k
0y+^{@lU
public Utility() DBL@Mp[<
{ K3M.ZRh\;`
;{L[1OP%e
ft1#f@b.
} 6h2keyod
I`H&b& .`
//线程睡眠 tx~,7TMS/
public static void sleep(int nSecond) A[ncwJ
{ ()bQmNqmO=
try{ ..X_nF
Thread.sleep(nSecond); o{`x:
} 7C0xKF
catch(Exception e) P.C?/7$7Z+
{ ]& ckq
e.printStackTrace (); T3@2e0u )
} z!O;s ep?/
} &1yJrj9y
( _6j@?u
//日志 dk nM|
public static void log(String sMsg) |oLGc!i
{ [n)ak)_/
System.err.println(sMsg); ye9GBAj /
} I9qFXvqL
"aF2:E'
_ia&|#n
public static void log(int sMsg) \}v@!PQl
{ R/Bjc}J'
System.err.println(sMsg); gv>DOez/
} ''@Tke3IG6
} (ct1i>g
5z,q~CU
\efDY[j/
/* 'g)f5n a[
**TestMethod.java x-k-Pd
*/ <efO+X!
package NetFox; *6` ^8Y\
slPr^)
:38h)9>RK
public class TestMethod { mMwV5\(
wg%Z
)VkVZf | S
public TestMethod() QOktIH
{ ///xx/weblogic60b2_win.exe ]pBEoktp
try{ !~9ASpqvPy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _Sfu8k>):
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9;v3 (U+:
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ve%ua]qA
fileFetch.start(); H!]&"V77
} W7WHDL^
catch(Exception e){e.printStackTrace ();} x)dLY.'|
xjbI1qCfe
0SYJ*7lPX
} lqOpADLS3
gU+yqT7=
pP":,8Q{
public static void main(String[] args) sx=1pnP9`
{ Lm=EN%*#9
new TestMethod(); -@>]iBl
} "rLm)$I
} e8 ]CB
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