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)); "5-^l.CKH
} V^JV4 `o
for(int i=0;i<nEndPos.length-1;i++) N F2/B#q
{ S'A>2>
nEndPos = nStartPos[i+1]; (5R?#vj
} +s,Qmmb7)
nEndPos[nEndPos.length-1] = nFileLength; g6Q!8
} 7N-w eX
} Fz1_w$^
f#?fxUH~
h!&prYx
//启动子线程 {U!8|(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .z 6fv
for(int i=0;i<nStartPos.length;i++) GqWB{$J;"
{ 2W/?q!t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \]=7!RQ\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kB/D!1 "
nStartPos,nEndPos,i); ,=tD8@a<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |p><'Q%*
fileSplitterFetch.start(); dik:4;
} 4"{ooy^Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2ggdWg7z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0o+6Q8q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y9_K, g
nEndPos = " + nFileLength); A3|Dz&@:
// fileSplitterFetch[nPos.length-1].start(); D$bIo"
F_;vO%}
%%NlTE8*
//等待子线程结束 -sw .
//int count = 0; /wP@2ADB
//是否结束while循环 L%Ow#.[C2
boolean breakWhile = false; W.dt:_
Rn{iaM2Y<
: y5<go8e
while(!bStop) kBYNf =
{ Hj:r[/
write_nPos(); ;k7xMZs
Utility.sleep(500); L1ieaKw
breakWhile = true; lmfi
I3,= 0z
@r#v[I
for(int i=0;i<nStartPos.length;i++) .Jt[(;
{ ;\lW5ZX
if(!fileSplitterFetch.bDownOver) lD"(MQV@0
{ sYjpU
breakWhile = false; O>^C4c!
break; P5 K' p5}#
} *tgnYa[l
} | \'rP_I>
if(breakWhile) W6"v)Jc>_
break; 3 |hHR
VwOW=4`6
Svc|0Ad&
//count++; SILQ
//if(count>4) J]&y$?C
// siteStop(); O9EKRt
} I9:Cb)hbU]
l~6?kFy9h
o'W5|Gy
System.err.println("文件下载结束！"); uoHNn7W
} %,D<O,N
catch(Exception e){e.printStackTrace ();} &jsVw)Ue
} 7PANtCFb&
4g :>[q
5e$~)fL
//获得文件长度 F8;dKyT?q
public long getFileSize() dl~%MWAVb
{ ?gJy3@D
int nFileLength = -1; 6`]$qSTS
try{ A8pIs
URL url = new URL(siteInfoBean.getSSiteURL()); D9FJ 1~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vgUb{D
httpConnection.setRequestProperty("User-Agent","NetFox"); 5m9*85Ib
{@tv>!WW
4?-.ZUT-1
int responseCode=httpConnection.getResponseCode(); qEpi]=|
if(responseCode>=400) iMs5zf<M
{ hRty [
processErrorCode(responseCode); WHjUR0NZ
return -2; //-2 represent access is error R}lsnX<
} SE),":aY
w9,iq@
2 !At2P2
String sHeader; VUhbD
SQqD:{#g"
L{(QpgHZ
for(int i=1;;i++) #B:hPZM1
{ O2BW6Wc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 91$]Qg,lB
//Utility.log(in.readLine()); %,Ap7X3:QT
sHeader=httpConnection.getHeaderFieldKey(i); :{oZ~<
if(sHeader!=null) ~-PjW#J%
{ :cGt#d6
if(sHeader.equals("Content-Length")) {K9/HqH
{ _>9.v%5cs(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ti'}MC+0
break; -u?S=h}
} ,(;lIP
} 3:8{"md@2
else #Sa27$&.>
break; OtGb<v<_H
} ^NX"sM0g
} .!G94b
catch(IOException e){e.printStackTrace ();} xA9:*>+>
catch(Exception e){e.printStackTrace ();} >lBD<;T
(HSgEs1d
g_G6~-.9I
Utility.log(nFileLength); e_V O3"
%-<'QYYP
#/I[Jqf
return nFileLength; ]|sAK%/
} nv0]05.4
t`+'r}=d
h}]fnA
//保存下载信息（文件指针位置） ~M\I;8ne
private void write_nPos() J,zO2572u
{ 4"xPr[=iG
try{ cCa|YW^j
output = new DataOutputStream(new FileOutputStream(tmpFile)); NcP.;u;`
output.writeInt(nStartPos.length); {;.T7dL
for(int i=0;i<nStartPos.length;i++) 2D:fJ~|-[
{ S-YM%8A[
// output.writeLong(nPos); |]aE<`D
output.writeLong(fileSplitterFetch.nStartPos); KyzFnVH3)
output.writeLong(fileSplitterFetch.nEndPos); ~_s{0g]B
} HW7; {QMg
output.close(); *X4PM\ck
} !}4MN:r
catch(IOException e){e.printStackTrace ();} ,:`ND28V7
catch(Exception e){e.printStackTrace ();} JB>b`W9
} A0fFv+RN3
(sQr X{~
I(9R~q
//读取保存的下载信息（文件指针位置） "h|'}7p
private void read_nPos() 9Ffp2NW`;
{ _z54Ycr4H
try{ C#H:-Q&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !vk|<P1
int nCount = input.readInt(); >5j<4ShW
nStartPos = new long[nCount]; zcva-ze:;
nEndPos = new long[nCount]; '&sE=.
for(int i=0;i<nStartPos.length;i++) (XXheC
{ P9S2?Q
nStartPos = input.readLong(); hAm`NJMSO
nEndPos = input.readLong(); > ]8a3x
} 9JWa$iBH@
input.close(); OQ,NOiNkap
} uaOKv.%
catch(IOException e){e.printStackTrace ();} NHl|x4Zpw
catch(Exception e){e.printStackTrace ();} +n7?S~R$
} ~u.T-0F
UThB7(O,
) /v6l
private void processErrorCode(int nErrorCode) rvyrxw%[
{ /"?HZ% W
System.err.println("Error Code : " + nErrorCode); z.6$W^
} (?H0+zws^
Q43|U4a
4]/7 )x?R
//停止文件下载 ^::EikpF%
public void siteStop() >+mD$:L
{ 8&Myva
bStop = true; T2D<UhP
for(int i=0;i<nStartPos.length;i++) 5P .qXA"D
fileSplitterFetch.splitterStop(); qiZO _=0
8`b`QtGf
*c)uGz'cD
} @m?QR(LJ
} } %'bullT
//负责部分文件的抓取 Pub0IIs
**FileSplitterFetch.java ;r/;m\V
*/ 'SYo_!
package NetFox; S2>c#BQ
kqb0>rYa
8_&CT :u>
import java.io.*; BI:k#jO!
import java.net.*; TM8=U-A
&vovA} F
{T'GQz+R"
public class FileSplitterFetch extends Thread { zd]D(qeX
+f0~D(d!_
t |W)
String sURL; //File URL f1PN|
long nStartPos; //File Snippet Start Position \ j.x0/;
long nEndPos; //File Snippet End Position fZKt%m
int nThreadID; //Thread's ID 4gSH(*}
boolean bDownOver = false; //Downing is over jEz+1Nl)
boolean bStop = false; //Stop identical nJ?^?M'F%
FileAccessI fileAccessI = null; //File Access interface `O^G5 0
_28<m JfG
OquAql:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 39 Y(!q
{ I =Wc&1g
this.sURL = sURL; YHV-|UNF
this.nStartPos = nStart; qEUT90
this.nEndPos = nEnd; QHBtWQgS
nThreadID = id; fWGOP~0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^")F7`PF
} d {2
~^)^q8
2eQdQwX
public void run() JM.XH7k
{ RE3Z%;'
while(nStartPos < nEndPos && !bStop) ?RFg$Z'^
{ 6qo^2
uk`8X`'
iF+RnWX\
try{ $mA5@O~C5\
URL url = new URL(sURL); :Zw@yt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }iBC@`mg(
httpConnection.setRequestProperty("User-Agent","NetFox"); Zt3}Z4d
String sProperty = "bytes="+nStartPos+"-"; K,xW6DiH
httpConnection.setRequestProperty("RANGE",sProperty); pL1s@KR
Utility.log(sProperty); %bb~Y"
qBk``!|s]
ts9pM~_~
InputStream input = httpConnection.getInputStream(); ;SKh
//logResponseHead(httpConnection); #6S75{rnW"
(9fdljl],:
3mt%!}S
byte[] b = new byte[1024]; )E7 FA|
int nRead; \ SCy$,m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N1--~e
{ @fn6<3
nStartPos += fileAccessI.write(b,0,nRead); ? S=W&
//if(nThreadID == 1) h=RDO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _EYB 8e
} &bC}3D
0??Yr
R 4EEelSZu
Utility.log("Thread " + nThreadID + " is over!"); hY\{|
bDownOver = true; J0<p4%Cf
//nPos = fileAccessI.write (b,0,nRead); CSn<]%GL
} ddpl Pzm#
catch(Exception e){e.printStackTrace ();} 7$T8&Mh
} )q?$p9
} ML!9:vz
7|D|4!i2Y
$@[)nvV\
//打印回应的头信息 KXBL eR&^
public void logResponseHead(HttpURLConnection con) s^C;>
{ !QC<n/
for(int i=1;;i++) /#q")4Mf
{ NtZ6$o<Y
String header=con.getHeaderFieldKey(i); J1 tDO?
if(header!=null) ,?b78_,2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6Dzs?P
Utility.log(header+" : "+con.getHeaderField(header)); xUj2]Q>R+
else r\mPIr|
break; kV^?p
} =:5<{J OG
} {rGYRn,
$pu3Ig$^
V/H@vKN2
public void splitterStop() I6w/0,azC
{ M/w{&&
bStop = true; Y+|PY? ~
} (|0b7|'T
#S?c ;3-
'O "kt T
} ONWO`XD
ZlM_m >,o
wznn #j
/* t,Q'S`eTU
**FileAccess.java Jk*QcEE=
*//文件访问(定位，写) n0FYfqH
package NetFox; /+P5)q TKL
import java.io.*; cdp{W
4<yK7x
BGpk&.J
public class FileAccessI implements Serializable{ *R!]47Y d
bA+[{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pX]21&F
RandomAccessFile oSavedFile; >Fh#DmQ
long nPos; [D9:A
KL~AzLI
Qg{WMlyOP
public FileAccessI() throws IOException @ay|]w
{ y{;u@o?T
this("",0); yjv&4pIc1
} (olLB
1w) fu
Q %y,;N"ro
public FileAccessI(String sName,long nPos) throws IOException L`pY27|
{ yjR)Z9t
oSavedFile = new RandomAccessFile(sName,"rw"); |P~q/Wff
this.nPos = nPos; m|`VJ0
oSavedFile.seek(nPos); 2moIgJ
} ` Rsl] GB
BWohMT
i)8gCDc
public synchronized int write(byte[] b,int nStart,int nLen) ;6zPiaDQ
{ ?0m?7{
int n = -1; n8Q* _?Z/
try{ _4Ii5CNNU
oSavedFile.write(b,nStart,nLen); b+_hI)T
n = nLen; DUQ9AT#3
} CJ:uYXJJ:z
catch(IOException e) h%/ssB
{ dGa@<hg
e.printStackTrace (); .2/,XwIr
} %L28$c3p
K^8@'#S
#[Z<=i~C
return n; HmFNE$k
} vD_u[j]
y3Y2QC(
T4vogoy
} (26Bs':M~
eC.w?(RB
W.z$a.<(rF
/* F@Pem
**SiteInfoBean.java a4:`2
*/ iY}QgB< M
package NetFox; 9A(n_Rs7?
/#@LRN<oCq
2$iw/r
public class SiteInfoBean { f>|9 l
rtcJ=`)0`
i_|h{JK)
private String sSiteURL; //Site's URL <xXiJU+
private String sFilePath; //Saved File's Path sw[<VsxjR
private String sFileName; //Saved File's Name bGhhh/n
private int nSplitter; //Count of Splited Downloading File 8rla0d@
PQ6T|>
hT\p)w
public SiteInfoBean() q$bHO
{//nSplitter的缺省值为5 Ml'bZLwq
//default value of nSplitter is 5 ="/R5fp
this("","","",5); Dr4?Ow
} |}l@w+N3
22l|!B%o
B9%yd*SJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @>d&5}F_>{
{ q]2}UuM|U
sSiteURL= sURL; K!pxDW}
sFilePath = sPath; $_4oN(WSz
sFileName = sName; \Mobq
this.nSplitter = nSpiltter; F! |TW6)gv
T3=-UYx]
iuvtj]/
} oVKsic?
v'mJ~tz
CD XB&%Sr
public String getSSiteURL() K8e4ax
{ 6$xo# }8
return sSiteURL; :< KSf#O
} UXcH";*9b
,U} 5
<z~2d
public void setSSiteURL(String value) @g@fL%
{ CDwFVR'_Af
sSiteURL = value; j]cXLY
} Z<$E.##
6KBzlj0T+
yg-L^`t+B5
public String getSFilePath() vTe$77n
{ +=,4@I%
return sFilePath; \N-| iq
} hi4h0\L!}
q.u[g0h;
b7>,-O
public void setSFilePath(String value) [~Z'xY y
{ 7Y_fF1-wY
sFilePath = value; ~%8Q75tn.
} $9 &Q.Kpq>
~|0F?~eR7
FBwncG$]F*
public String getSFileName() jx5[bUp4u
{ E<98ahZ?l
return sFileName; Tvksf!ba
} F'Y2f6B
6S&=OK^
U||w6:W5
public void setSFileName(String value) Zh fD`@>&
{ N.Wdi
sFileName = value; I[cV"BDa
} 9wYtOQ{g
"JQt#[9l
zw%n!wc_\
public int getNSplitter() ;ow~vO,x
{ )68fm\t(
return nSplitter; DESViQM
} !=h|&Vta
~QEXB*X-g'
P9tQS"Rs
public void setNSplitter(int nCount) M~{P',l*
{ ]zwqGA
nSplitter = nCount; w;SH>Ax:
} ?3"D| cS1
} kvgs $
cf[u%{ 6Y
v<J;S9u=
/* vX0I^8.
**Utility.java s eZ<52f2
*/ 3}#XA+Z
package NetFox; vo( j@+dz
b-(UsY:
kFIB lPV
public class Utility { ?#EXG
q V UUuyF
<Ec)m69P
public Utility() t{S{!SF4
{ |gRgQGeB
=Z>V}`n
Y7t{4P
} R,5$ 0_]|+
61rh\<bn
//线程睡眠 k]/6/s\
public static void sleep(int nSecond) M+R)P+
{ On.x~t
try{ `w=H'"Zv
Thread.sleep(nSecond); LI|HET_
} -^jLU FC
catch(Exception e) zI:5I@ X
{ ^.1VhTB
e.printStackTrace (); >'TD?@sr
} hYUV9k:
} eW*ae;-
^RyTK|SQ
//日志 %FWfiFV|<
public static void log(String sMsg) A{Htpm~
{ aLk2#1$g
System.err.println(sMsg); L%O8vn^3
} j _9<=Vu
4Z~Dxo
W]}V<S$
public static void log(int sMsg) a={qA4N
{ No&[ \;
System.err.println(sMsg); sAN:C{
} ;q&D,4r]
} YB3=ij!K
rHBjR_L.2
Bpo68%dx89
/* kBT}Siw
**TestMethod.java u&_U CJCf
*/ UR2)e{RXg
package NetFox; 5"~^;O
yj+b/9My
"3oU (RA
public class TestMethod { :QL p`s
&FF. Ddt{
`h3}"js
public TestMethod() XK-x*|
{ ///xx/weblogic60b2_win.exe "}+/0$F
try{ GFa/9Bi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Tn-]0hWkP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >D4Ez
SiteFileFetch fileFetch = new SiteFileFetch(bean); tRBK1h
fileFetch.start(); z ;Nk& <?
} hBE>ea
catch(Exception e){e.printStackTrace ();} TPFmSDq
^tcBxDC"]
emPm^M5/K
} s;WCz
iX6jvnJ:/
xF|*N<9(</
public static void main(String[] args) Z?'|9FM
{ 1W<_5 j_
new TestMethod(); M F: Eu
} x.Ml~W[
} #zs\Z]3#
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