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)); IE0hC\C}
} [AA*B
for(int i=0;i<nEndPos.length-1;i++) cvk$ I"q+
{ ?]]7PEee*
nEndPos = nStartPos[i+1]; 0;/},B[A
} -|WQs'%O
nEndPos[nEndPos.length-1] = nFileLength; '[zy%<2sL
} VZ1u/O?ub
} fgW>~m.W
Yp@i{$IUW
`iQ9 9
//启动子线程 [+2iwfD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M/LC:,
for(int i=0;i<nStartPos.length;i++) Zk*!,,P!
{ 1(`UzC=R|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pe`eF(J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M\!z='Fi
nStartPos,nEndPos,i); ibqJ'@{=e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1$toowb"Zy
fileSplitterFetch.start(); :H8`z8=0f{
} )r`F}_CEL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p3W-*lE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |qq7vx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Js0hlWu
nEndPos = " + nFileLength); "74Rn"d5
// fileSplitterFetch[nPos.length-1].start(); 3o.9}`/
@ rG=>??k
@@pI>~#zh
//等待子线程结束 =hq+9 R8=
//int count = 0; #k/NS
//是否结束while循环 [:"7B&&A
boolean breakWhile = false; S uo
XR@C^d
{IG5qi?/E)
while(!bStop) 1c19$KHu
{ 8;q2W F{AX
write_nPos(); C9Xj)5k@R
Utility.sleep(500); 6 66f;h
breakWhile = true; +hL%8CVU M
=*'K'e>P3
zv>7;En3
for(int i=0;i<nStartPos.length;i++) Pgo^$xn'6
{ V 3yt{3Or
if(!fileSplitterFetch.bDownOver) FI=]K8
{ (;T g1$
breakWhile = false; o"Mhwh
break; o4Hp|iK&0
} Uf`~0=w
} 4cQ|"sOzD
if(breakWhile) ]R%+
break; fKkH [
d'UCPg<Y
Cj3C%W
//count++; >sl#2,br
//if(count>4) -+,3aK<[
// siteStop(); Jd-u?
} \ QE?.Fx
:@c\a99Kx
*L+)R*|:&
System.err.println("文件下载结束！"); k=``Avp?
} =1e>$E#
catch(Exception e){e.printStackTrace ();} $^ZugD
} 9yWQ}h
>j}.~$6dj_
m6iQB\ \
//获得文件长度 =ec"G2$?"
public long getFileSize() |x/00XhS
{ uh 3yiDj@a
int nFileLength = -1; |4?O4QN
try{ M.h8Kr!.
URL url = new URL(siteInfoBean.getSSiteURL()); w^N3Ma
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s;!Tz)
httpConnection.setRequestProperty("User-Agent","NetFox"); T$vDw|KSVP
M_Z(+k{Gy
%D $+Z(
int responseCode=httpConnection.getResponseCode(); %[J|n~8_Z
if(responseCode>=400) /AhN$)(O
{ Api<q2@R
processErrorCode(responseCode); /gUD!@
return -2; //-2 represent access is error T/Fj0'
} {6Qd,CX
! 1wf/C;=
I]vCra
String sHeader; (n {,R
:o=a@Rqx
TW)~&;1l
for(int i=1;;i++) kD{qW=Lpn
{ _=ziw|zI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w\(;>e@
//Utility.log(in.readLine()); Xn3 \a81
sHeader=httpConnection.getHeaderFieldKey(i); ,HHCgN
if(sHeader!=null) KXvBJA$
{ ,3p$Z
if(sHeader.equals("Content-Length")) s$PPJJT{b
{ XPd@>2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r.#"he_6!.
break; \95O
} Qs1e0LwA9
} lq*{2M{[
else EI!e0V1!
break; f.Feo
} 8-uRn38
} Y>i5ubR~
catch(IOException e){e.printStackTrace ();} b@?pofZ`k
catch(Exception e){e.printStackTrace ();} vzPuk|q3
z(JDLd
eA'1
Utility.log(nFileLength); p"k[ac{
tShyG!b
dp~] Wx
return nFileLength; Uh=@8v
} zM+eb| >cr
'%\FT-{
p"ElO,\
//保存下载信息（文件指针位置） '3eL^Aq
private void write_nPos() Z&[_8Y5j
{ ;fl3'.S[
try{ 2uy<wJE>
output = new DataOutputStream(new FileOutputStream(tmpFile)); ocDAg<wo
output.writeInt(nStartPos.length); ]46#u=y~3
for(int i=0;i<nStartPos.length;i++) k<i#agq
{ LktH*ePO
// output.writeLong(nPos); ccm(r~lhJ
output.writeLong(fileSplitterFetch.nStartPos); s?pd&_kOv3
output.writeLong(fileSplitterFetch.nEndPos); KV {J>J1
} l0GsY.~,
output.close(); :$5$H
} 1$1[6 \3v
catch(IOException e){e.printStackTrace ();} 22_%u=p-|
catch(Exception e){e.printStackTrace ();} hUO&rov3@
} +:jx{*}jo
3Lw&HtH
GT3?)g{Z
//读取保存的下载信息（文件指针位置） 4ht+u
private void read_nPos() RI</T3%~
{ +q-/~G'
try{ K]s*rPT/,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,"U_oa3
int nCount = input.readInt(); ?D8+wj
nStartPos = new long[nCount]; 5*P+c(=
nEndPos = new long[nCount]; w_hN2eYo&e
for(int i=0;i<nStartPos.length;i++) [t}\8^y
{ " _{o}8L
nStartPos = input.readLong(); OD~B2MpM>
nEndPos = input.readLong(); x!RpRq9
} SE;Yb'
input.close(); 2?./S)x)
} || 0n%"h>i
catch(IOException e){e.printStackTrace ();} <yw(7
catch(Exception e){e.printStackTrace ();} K|^'`FpPO
} /@qnEP%
5kbbeO|0G
U,e'vS{
private void processErrorCode(int nErrorCode) _dk/SWb)
{ iB0#Z_
System.err.println("Error Code : " + nErrorCode); M*n@djL$\~
} _&xi})E^O]
lU&[){
66 @#V
//停止文件下载 I`-N]sf^
public void siteStop() @&fAR2
{ ?Q#yf8
bStop = true; roNRbA]
for(int i=0;i<nStartPos.length;i++) j,@@[{tu
fileSplitterFetch.splitterStop(); LUN"p#1
-Mx\W|YK
wu53e= /
} YOE!+MiO
} GX-V|hLaGX
//负责部分文件的抓取 oTLA&dy@
**FileSplitterFetch.java o{r<=X ysM
*/ RW I7eC
package NetFox; #ssSs]zl
jS<(Oo
%f'mW2
import java.io.*; (]gd$BgD
import java.net.*; :+*q,lX8
TVs#,
3I):W9$Qp
public class FileSplitterFetch extends Thread { eF=cMC
XMpa87\
& cV$`L
String sURL; //File URL n4%ZR~9WH
long nStartPos; //File Snippet Start Position kACgP!~/1
long nEndPos; //File Snippet End Position ~>-MVp
int nThreadID; //Thread's ID %!X9>i>
boolean bDownOver = false; //Downing is over 6zR9(c:a~
boolean bStop = false; //Stop identical P~d&PhOe
FileAccessI fileAccessI = null; //File Access interface x4=Sm0Ro|V
hw9qnSeRy
'h.:-1# L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException su\iUi
{ ;%W]b
this.sURL = sURL; YkuFt>U9,
this.nStartPos = nStart; 7G]v(ay
this.nEndPos = nEnd; vnr{Ekg
nThreadID = id; 9Q/t+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qr<RMs
} kVeR{i<*(
jRGslak;
XV %DhR=
public void run() |9'`;4W
{ kfj)`x
while(nStartPos < nEndPos && !bStop) z}z 6Vg
{ dgp1B\
orON)Sks
qSA]61U&
try{ l.nd Wv
URL url = new URL(sURL); o7i>D6^^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5x?YFq6k
httpConnection.setRequestProperty("User-Agent","NetFox"); /?*GJN#
String sProperty = "bytes="+nStartPos+"-"; w_ONy9
httpConnection.setRequestProperty("RANGE",sProperty); bo|3sN+D
Utility.log(sProperty); w]O[{3"
1Xn:B_pP
` G-V %
InputStream input = httpConnection.getInputStream(); >h3m/aeNC
//logResponseHead(httpConnection); scQnL'\
'^!#*O
A29R5
byte[] b = new byte[1024]; #UesXv
int nRead; &m=73RN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "zZZ h
{ bGtS! 'I
nStartPos += fileAccessI.write(b,0,nRead); 6Q*Zy[=
//if(nThreadID == 1) *YO^+]nmY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sD ,=_q@
} -\[H>)z]RB
QCAoL.v
aDZ,9}
Utility.log("Thread " + nThreadID + " is over!"); @i <vlHpl
bDownOver = true; FKBI.}A?!'
//nPos = fileAccessI.write (b,0,nRead); PrqyJ
} z;Jz^m-
catch(Exception e){e.printStackTrace ();} 9y+0Zj+.
} 38E %]*5F
} ;_p$5GVR|
L.?QZN%cN
ISHzlEY
//打印回应的头信息 fW=vN0Z
public void logResponseHead(HttpURLConnection con) c]%~X&Tg`
{ w<&R|= 93
for(int i=1;;i++) %EH{p@nM&-
{ ~YRG9TK
String header=con.getHeaderFieldKey(i); oH='\M%+
if(header!=null) zQ~ax!}R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ms 3Sri
Utility.log(header+" : "+con.getHeaderField(header)); u*=8s5Q[
else 572{DC&T
break; [nASMKK0
} 'W*:9wah
} l0w<NZF
^_gH}~l+U
e);`hNLih
public void splitterStop() Z^!% b
{ Fs(FI\^
bStop = true; 0fzHEL
} y|/[;
1I?`3N
2h:{6Gq8
} D/YMovH%
i_e%HG
Dv"HFQuF
/* Marx=cNj
**FileAccess.java UQ#t &
*//文件访问(定位，写) GIZw/L7Yb
package NetFox; +L|x^B3
import java.io.*; b/"gUYo
ub;:"ns}
C2{*m{ D
public class FileAccessI implements Serializable{ %uw7sGz\
\q@Co42n\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0bG#'.-
RandomAccessFile oSavedFile; 7!dj&?
long nPos; m6uFmU*<M}
k8c(|/7d
o~7D=d?R
public FileAccessI() throws IOException Tq?7-_MLC$
{ 5=#2@qp
this("",0); .*edaDi
} +ib&6IU
(q@%eor&}
hg2Ywzfm-
public FileAccessI(String sName,long nPos) throws IOException [}HS[($
{ ik#ti=.
oSavedFile = new RandomAccessFile(sName,"rw"); fjCFJ_
this.nPos = nPos; d$^@$E2f
oSavedFile.seek(nPos); y* :C~
} U@9v(TfV
&F:%y(;{Y
2HO2
public synchronized int write(byte[] b,int nStart,int nLen) I?RUVs
{ I? ="Er[g}
int n = -1; iG#92e4
try{ ,FwpHs $A
oSavedFile.write(b,nStart,nLen); fV2w &:^3
n = nLen; Eh^gR`I
} RN&6z"|jR
catch(IOException e) EM(%|#
{ /dO*t4$@?
e.printStackTrace (); @/,0()*dL
} zs6rd83#
PeIKx$$Kl{
IrUoAQ2xpG
return n; V?)YQB
} eX1_=?$1P
+|Izjx]ZV
d_!}9
} 8DX5bB
7 0PGbAD
+/ {lz8^,
/* Cp+tcrd_s
**SiteInfoBean.java ;l^'g}dQ^
*/ A'$>~Ev
package NetFox; znDpg{U(
Jd~Mq9(
h^v#?3.@
public class SiteInfoBean { Ii#+JY0k
l$[,V:N
u{7->[=
private String sSiteURL; //Site's URL 0"Euf41
private String sFilePath; //Saved File's Path Kn1T2WSAg
private String sFileName; //Saved File's Name $&!|G-0'
private int nSplitter; //Count of Splited Downloading File ^q`RaX)
hYh~%^0dt
K:A:3~I!NW
public SiteInfoBean() M)U)Sc zHO
{//nSplitter的缺省值为5 \GV'{W+o2
//default value of nSplitter is 5 Ls+vWfF=#
this("","","",5); ej7L-~lxQ
} zKI1
R#i`H(N
2a;[2':
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZvLI~ul(zT
{ 'v@*xF/L6a
sSiteURL= sURL; bc:3 5.
sFilePath = sPath; /EJy?TON*
sFileName = sName; !x\\# 9
this.nSplitter = nSpiltter; .s?^y+e_
:sw@1
;.<HpDfG_
} ZmycK:f
uH(M@7"6_!
|Qb@.
public String getSSiteURL() \%9QE
{ E^A!k=>
return sSiteURL; +~*e B
} I0><IaFy
ef!f4u\
H: ;XU
public void setSSiteURL(String value) $Yp.BE<}
{ U(Bmffn4Z
sSiteURL = value; 2Q7X"ek~[
} fz?woVn
:`lP+y?a1
}:u-l3e
public String getSFilePath() ?G<?:/CU
{ |qwx3 hQ?
return sFilePath; f@$kK?c?
} d'H gek{T
|DPq~l(d
<>Ha<4A =E
public void setSFilePath(String value) =(Y0wZP|
{ jW4>WDN:
sFilePath = value; 5y] %Cu1.u
} MttFB;Tp
]g }5p4*&
G{O{ p
public String getSFileName() ic4hO>p&
{ 4@Z!?QzW
return sFileName; E$&bl
} ks %arm&
r:Q=6j,
3.g4X?=zd
public void setSFileName(String value) $dWYu"2CD
{ VS!v7-_N5
sFileName = value; I~Qi):&x
} c4r9k-w0E
8H T3C\$s
OF)*kiJ
public int getNSplitter() [Q\(kd*4
{ 3xmPY.
return nSplitter; D #7q3s
} P2 qC[1hYH
*cCj*Zr]
kY6_n4
public void setNSplitter(int nCount) ]=]MJ3_7
{ ykH@kv Qt
nSplitter = nCount; xP;>p| M
} &}|`h8JA]K
} }f% Qk0^
lDF7~N9J_
g:!R't?
/* $9xp@8b\_
**Utility.java e.#,9
*/ (d*||"
package NetFox; QC&,C}t,
WS?Y8~+{5
?AQA>D#W
public class Utility { ts("(zI1E
\PFjw9s
2$VSH&
public Utility() feeHXKD|
{ 1'iQlnMO@
g6S-vSX,
W7@Vma`
} %`\Qtsape
#JY>
//线程睡眠 "3|OB, <;:
public static void sleep(int nSecond) -j:yEZ4Oy
{ skTtGz8R[
try{ .7:ecFKk
Thread.sleep(nSecond); R9D2cu,{
} 6+"gk(
catch(Exception e) -w8?Ur1x:
{ j~>J?w9<O
e.printStackTrace (); R6:m@
} JsMN_%y?
} }jU)s{>fb
.cx9+;
//日志 P"t Dq&
public static void log(String sMsg) Snp(&TD<<
{ ~V?\@R:g
System.err.println(sMsg); }<w9Jfr"X
} %qqeL
tB4yj_ZF
qPJSVo
public static void log(int sMsg) D0MW~Y6{
{ 3H4T*&9;n
System.err.println(sMsg); >IA1 \?(
} @+)T"5_Y[
} Y?zo")
<Lt"e8Z>x
rSm#/)4A
/* o]&P0 b
**TestMethod.java 5Z"N2D)."
*/ Y%@;\
package NetFox; BQeg-M
T!pZj_ h=
"A5z!6T{
public class TestMethod { L'"c;FF02i
x&m(h1h
$(08!U
public TestMethod() mv`b3 $
{ ///xx/weblogic60b2_win.exe nPl,qcyY
try{ U!RIeC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %|f@WxNrU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~x@V"rxGw
SiteFileFetch fileFetch = new SiteFileFetch(bean); F[F NtZ
fileFetch.start(); oR7f3';?6
} Bs>S2]
catch(Exception e){e.printStackTrace ();} PlgpH'z4$
f8UO`*O
sqjDh
} huR ^l
N+H[Y4c?F&
*A")A.R
public static void main(String[] args) w vI v+Q9
{ ed3wj3@
new TestMethod(); %\)AT"
} }g|9P SbJ
} / T_v8{D
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