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)); ~{2@-qcm
} /%)MlG
for(int i=0;i<nEndPos.length-1;i++) SB$~Btr
{ *aG0p&n}
nEndPos = nStartPos[i+1]; EnwiE
} -[^wYr=
nEndPos[nEndPos.length-1] = nFileLength; (e F5?I
} 07/5RFmJ
} -BEPpwb<g
?ZTB u[
27u$VHwb
//启动子线程 `f6Qd2\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dE^(KBF
for(int i=0;i<nStartPos.length;i++) S1$\D!|1
{ vaTXu*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M$! 0ikh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \+cQiN b@
nStartPos,nEndPos,i); qn+mlduU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 35&&*$Jm
fileSplitterFetch.start(); M{~eI
} }f6.eqBX4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !p0FJ].g,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @M,KA {e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Bm~>w`1wK
nEndPos = " + nFileLength); ;uba
// fileSplitterFetch[nPos.length-1].start(); >!bYuVHA
HnOF_Twq
hrS/3c'<Z
//等待子线程结束 r9*{)"
//int count = 0; XZKOBq B]
//是否结束while循环 ghms-.:b8
boolean breakWhile = false; <<UlFE9"
k{@z87+&
Ch7eUTqA@
while(!bStop) AiO,zjM=
{ i"_f46rP
write_nPos(); b~#rUOXb8?
Utility.sleep(500); hR=4w$
breakWhile = true; 4SG[_:+!
oiFtPki
n`^</0
for(int i=0;i<nStartPos.length;i++) (TnYUyFP`
{ v- {kPc=:#
if(!fileSplitterFetch.bDownOver) `P# h?tZ
{ OW #pBeX99
breakWhile = false; Y61E|:fV!
break; F." L{g
} dFFB\|e;0
} kV(?u_ R
if(breakWhile) SKcAZC
break; d]@9kG
0K#dWc}"a
:;7qup
//count++; /iukiWeW
//if(count>4) CdEJ/G:
// siteStop(); B<0lif|
} [2&Fnmjk}X
W?6RUyMC$T
+x4o#N
System.err.println("文件下载结束！"); $6Ty~.RP5H
} 7L]fCw p[
catch(Exception e){e.printStackTrace ();} bgEUG
} PDGh\Y[AK,
[9>1e
d[O.UzQ
//获得文件长度 =Wl CE_
public long getFileSize() ;zh|*F>
{ H:~LL0Md%
int nFileLength = -1; hPEK@
try{ $(_i>&d<
URL url = new URL(siteInfoBean.getSSiteURL()); c\RDa|B,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v$,9l+p/
httpConnection.setRequestProperty("User-Agent","NetFox"); 5gEUE{S
(# ?~^ut
sS+9ly{9J
int responseCode=httpConnection.getResponseCode(); ]INbRytvc
if(responseCode>=400) )IhI~,0Nmj
{ 9D 0ujup
processErrorCode(responseCode); g(<@r2p
return -2; //-2 represent access is error NB,iC [e
} + 1v@L
=;T971L`
0}w>8L7i{
String sHeader; U` bvv'38#
.m+KXlP
a{H~>d<?
for(int i=1;;i++) o3uv"# C
{ LiN{^g^fx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]huqZI
//Utility.log(in.readLine()); *.Kc-f4mP
sHeader=httpConnection.getHeaderFieldKey(i); "lUw{3
if(sHeader!=null) Va !HcG1^:
{ ob0clJX
if(sHeader.equals("Content-Length")) f PDnkr
{ w"aD"}3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3RGVH,
break; Nf3Kz#!B
} 67J=#%\
} rJg!2
else &z,w0FOre
break; fe&K2C%bm
} o[8Y%3
} Kh%9Oy
catch(IOException e){e.printStackTrace ();} >Y[{m $-
catch(Exception e){e.printStackTrace ();} 1UmV&
o&X!75^G>
9i9VDk{
Utility.log(nFileLength); D^f;dT;-
k^ID
3+(Fq5I
return nFileLength; _-&Au%QNJ`
} ;pC-0m0Y
]Nm_<%lT
7';PI!$
//保存下载信息（文件指针位置） JLs7[W)O
private void write_nPos() OyTBgS G?a
{ 3Vt-]DGX
try{ PUucYc
output = new DataOutputStream(new FileOutputStream(tmpFile)); A$%%;O
output.writeInt(nStartPos.length); A;{8\e
for(int i=0;i<nStartPos.length;i++) #&Biu}4D
{ ,qaIdw[
// output.writeLong(nPos); m]&d TZV
output.writeLong(fileSplitterFetch.nStartPos); >JnEhVRQJ9
output.writeLong(fileSplitterFetch.nEndPos); ("IRv>} 0
} C2!POf;GdN
output.close(); qzmY]N+w|
} f}#pKsX.
catch(IOException e){e.printStackTrace ();} +EkZyM~z2
catch(Exception e){e.printStackTrace ();} Y[*z6gP(
} bJGT^N@
dG6Mo76
Mi:$<fEX
//读取保存的下载信息（文件指针位置） [NH[n#
private void read_nPos() Ro?4tGn
{ Tb~(?nY5
try{ >\KBXS}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); syV&Ds)
int nCount = input.readInt(); V,&s$eQC
nStartPos = new long[nCount]; C>t1~^Q},9
nEndPos = new long[nCount]; nh,N(t9
for(int i=0;i<nStartPos.length;i++) 2<|+h= &
{ du`],/ 6
nStartPos = input.readLong(); d}IVYI
nEndPos = input.readLong(); lq+FH&
} '7wWdq
input.close(); ,AACE7%l
} JCS$Tm6y<_
catch(IOException e){e.printStackTrace ();} Vb0hlJb
catch(Exception e){e.printStackTrace ();} OTalR;:]r
} 27w]Q_C
8n1Sy7K!;
\6nWt6M
private void processErrorCode(int nErrorCode) /sC$;l
{ Z]"ktb;+[
System.err.println("Error Code : " + nErrorCode); `2Ff2D^ ?
} =yvyd0|35
2hu;N
:DQHb"(
//停止文件下载 (x#4BI}L9)
public void siteStop() ;^t<LhN:
{ QH#|R92:
bStop = true; O"_FfwO a
for(int i=0;i<nStartPos.length;i++) *H:;pIWP
fileSplitterFetch.splitterStop(); \ $z.x-U
3Pkzzyk_|D
rzEE|
} t$R|lv5<
} >qCUs3}C{*
//负责部分文件的抓取 (CO8t~J=
**FileSplitterFetch.java k`kmmb>
*/ "-(yZigQ
package NetFox; ;l+3l ez
%w_h8
[%z~0\lu8
import java.io.*; P\N$TYeH
import java.net.*; tAc[r)xFw
ZuILDevMD
C$ nT&06o
public class FileSplitterFetch extends Thread { El]Rrku
j$Gb>Ex>
EKq9m=Ua@o
String sURL; //File URL VO[s:e9L
long nStartPos; //File Snippet Start Position !:a pu!
long nEndPos; //File Snippet End Position @dD70T
int nThreadID; //Thread's ID UPUO8W)<Z6
boolean bDownOver = false; //Downing is over ="<+^$7:k
boolean bStop = false; //Stop identical )!){4c/
FileAccessI fileAccessI = null; //File Access interface sf7'8+wj>
>\3=h8zw
~h tV*R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |"vqM)V$
{ Y0aO/6
this.sURL = sURL; l`fjz-eE
this.nStartPos = nStart; h#'(UZ
this.nEndPos = nEnd; <~vamim#K
nThreadID = id; F;5.nKo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }3 RqaIY}
} %/-Z1Nv*#
>*B/Wy
}4 5|
public void run() WF-B=BRZ
{ doVBVTk^
while(nStartPos < nEndPos && !bStop) ~z%K9YcyU
{ 7*~ rhQ
w\8grEj
Cf J@|Rh
try{ kbBX\*{yh
URL url = new URL(sURL); L:%; Fx2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _~| j~QE]
httpConnection.setRequestProperty("User-Agent","NetFox"); =H3 JRRS
String sProperty = "bytes="+nStartPos+"-"; OGrp{s
httpConnection.setRequestProperty("RANGE",sProperty); cAV9.VS<L
Utility.log(sProperty); 2*F["E
_ B",? }
(]vHW+'
InputStream input = httpConnection.getInputStream(); KP -g<Zc
//logResponseHead(httpConnection); 4(|x@:wxm
K/ I3r_
p!|ok#sW
byte[] b = new byte[1024]; (,[m}Qb?!
int nRead; r,!7TuBl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B&+V%~/
{ G*3O5m
nStartPos += fileAccessI.write(b,0,nRead); ?)'j;1_=E3
//if(nThreadID == 1) #ZeZs31
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DNq=|?qn]
} o5@ l!NQ
Q!zg=_z-
"Z#97Jc+J
Utility.log("Thread " + nThreadID + " is over!"); w91{''sK
bDownOver = true; `BdZqXKG
//nPos = fileAccessI.write (b,0,nRead); :p%nQF,*f
} VfAIx]Fa
catch(Exception e){e.printStackTrace ();} vZq7U]RW
} &d[&8V5S
} u&9|9+"N
HhH[pE
cRDjpc]
//打印回应的头信息 ,AhQA
public void logResponseHead(HttpURLConnection con) K%1'zSAyK
{ ''s]6Jjw
for(int i=1;;i++) )PVX)2P_C
{ 593D/^}D
String header=con.getHeaderFieldKey(i); `7LN?- T
if(header!=null) 4?jXbC k~x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {~.h;'m
Utility.log(header+" : "+con.getHeaderField(header)); i$?i1z*c}
else XTXRC$B
break; RYZh"1S;k
} pMHY2t
} V+W,#5
66,?f<b
s>9w+|6Ji
public void splitterStop() #(?EL@5
{ XuVbi=pN.2
bStop = true; %($sj|_l
} hIuKs5`
Z6 E-FuO
dUk^DI,:l
} %TyR8 %
X25cU{
{()8 Wr
/* lGwX.cA!'
**FileAccess.java LBk1Qw}-
*//文件访问(定位，写) 6-{QU] #
package NetFox; RM|<(kq
import java.io.*; >t.2!Z_RQ
5lu620o
BXiuVx
public class FileAccessI implements Serializable{ JVD#wwic
B- N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AA:Ch?
RandomAccessFile oSavedFile; Z f4Xt Yn
long nPos; <*<7p{x
WFocA:
<VS\z(K
public FileAccessI() throws IOException l}&egq DC
{ n9B1NM5 \
this("",0); jFZJ #'CNS
} 3l0x~
-5l74f!i
v<,?%(g)7
public FileAccessI(String sName,long nPos) throws IOException qY]IX9'kV
{ cxFfAk\,en
oSavedFile = new RandomAccessFile(sName,"rw"); {a-p/\U
this.nPos = nPos; S^HuQe!#
oSavedFile.seek(nPos); *`>(K&
} U<|kA(5
r5xu#%hgp;
r]iec{ ^
public synchronized int write(byte[] b,int nStart,int nLen) j)?I]j/
{ iqig~fjK~
int n = -1; U{gJn#e/.
try{ ]7}2"?J4v
oSavedFile.write(b,nStart,nLen); eNY$N_P
n = nLen; 0.4c|-n
} &Y;z[+(P
catch(IOException e) r in#lu&N
{ q%i2'yE
e.printStackTrace (); `PnB<rf:*1
} ~Aq;g$IJZ
NYz{[LM
e*;-vS9H
return n; 7_)'Re#
} CS"2Sd 1`
5 5>^H1M
@[D-2s
} eVL'Ao&Ho
a]|P rjPI
`So*\#\T
/* `{s:lf
**SiteInfoBean.java t5G@M&d4Eo
*/ 3N|,c]|
package NetFox; /!rH DcR
dU+28
tJy6\~
public class SiteInfoBean { r5tC
sc\4.Ux%Q
8q{ %n
private String sSiteURL; //Site's URL tbrjTeC
private String sFilePath; //Saved File's Path Fr?o 4E6h
private String sFileName; //Saved File's Name N>giFj[dD
private int nSplitter; //Count of Splited Downloading File y)X1!3~(
`ySLic`
zFmoo4P/
public SiteInfoBean() RNE})B
{//nSplitter的缺省值为5 kaQn'5
//default value of nSplitter is 5 m!L&_Z|j
this("","","",5); %?1k}(qUeY
} Jf{6'Ub
rwGY)9|
73OFFKbsk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8Ih+^Y a
{ Rm`_0}5
sSiteURL= sURL; N|Mzj|i.
sFilePath = sPath; HWG5Ghu8,)
sFileName = sName; )<-\ F%&b
this.nSplitter = nSpiltter; k;/U6,LQ*
_@wXh-nc
L6c=uN
} U@yn%k9
[GJ_]w^}j
#)QR^ss)iw
public String getSSiteURL() yyb8ll?@a
{ NCbn<ojb
return sSiteURL; xhLVLXZ9
} ]p~w`_3v
i7v> 9p7
BR*,E~%
public void setSSiteURL(String value) Hz&a~
{ wK0vKdi
sSiteURL = value; *U|K~dl]K
} q'9u8b
.I_Mmaq;i
*P]FX-D3
public String getSFilePath() |{]W (/
{ i;>Yx#
return sFilePath; 8`l bKV
} :1NF#-2\f
Y4q;
~'k.'O{
public void setSFilePath(String value) musZCg$
{ '|V"!R)
sFilePath = value; ,\ [R\s
} YMx]i,u'+
f-&4x_5
Q]wM WV
public String getSFileName() &6V[@gmD
{ <XG&f
return sFileName; PLlad\
} |Am +f.
LldZ"%P
_3v6c
public void setSFileName(String value) }xXUCU<
{ 8i"v7}
sFileName = value; _dCdyf
} >qkZn7C
CR3<9=Lv>
YQGVQ[P
public int getNSplitter() OOJg%y*H
{ BnJpC<xm
return nSplitter; r/o1a't;
} IJ >qs8
nKpXRuFn\
foO/Yc
public void setNSplitter(int nCount) L|O[u^
{ x{y}pH"H
nSplitter = nCount; ;Qe-y|>
} L[;U Z)V@
} WrJgU&H{
fg"]4&`j-
+P YX.
/* mcbvB5U
**Utility.java =GH>-*qp
*/ SStaS<q'
package NetFox; /o@6?UH
2ZUI~:U Z
jD]Ci#|W
public class Utility { 3Wv-olv
(SMnYh4
zY_?$9l0
public Utility() mk*r^k`a
{ <!@*2/Q]J]
I_ O8 9Sgn
^\o3V<
} U~h f,Oxi
ppL*#/jYt
//线程睡眠 r2dU>U*:4
public static void sleep(int nSecond) %a\!|/;6
{ k2]fUP
try{ va6e]p*Oy
Thread.sleep(nSecond); r:rM~``
} i3 ?cL4
catch(Exception e) n[|*[II
{ K,B qVu
e.printStackTrace (); i{T mn
} \0bao<
} I$yFCdXr
LTsX{z
//日志 ~1xfE C/
public static void log(String sMsg) (x)}k&B;
{ <V?csx/eRd
System.err.println(sMsg); @-B)a Z
} al#BfcZW
=17d7#-
0<ze'FbV]
public static void log(int sMsg) 04o>POR
{ K14FY2"
System.err.println(sMsg); u?Pec:3%
} [2~^~K
} d`eX_]Z
b({K6#?'[
S1d^mu
/* z?Hi u6c-
**TestMethod.java /2s=;tA1
*/ Hsdcv~Xr;l
package NetFox; kD}w5 U
ZwzN=03T
Dt#( fuk#
public class TestMethod { *P:!lO\|
/w|!SZB
V= wWY*C
public TestMethod() 5)@UpcjUA
{ ///xx/weblogic60b2_win.exe ?**9hu\BG
try{ W{@,DQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +mu.W r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |XGj97#M
SiteFileFetch fileFetch = new SiteFileFetch(bean); S1vUP5cZ
fileFetch.start(); -e2f8PV?3
} 5I`_SOa!
catch(Exception e){e.printStackTrace ();} Yo-$Z-ud
T<a/GE/
>IT19(J;A
} UR{OrNg*
s!g06F
59R%g .2Y
public static void main(String[] args) ;:WM^S
{ uge~*S
new TestMethod(); r*F^8_YMK
} xGkc_
} 6d;_}
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