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)); 'GkvUrD9D$
} <KtBv Ip]
for(int i=0;i<nEndPos.length-1;i++) 5:c;RRn
{ +kM\ D~D1
nEndPos = nStartPos[i+1]; `4LJ;KC(
} ;d4y{
nEndPos[nEndPos.length-1] = nFileLength; `qE4U4
} J;~E<_"Hn
} GWgd8x*V
OZ^h\m4
?1CJf>B>
//启动子线程 (v!mR+\x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0 sZwdO
for(int i=0;i<nStartPos.length;i++) |) O):
{ D i+4Eb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0pD[7~^o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y`rL=N#
nStartPos,nEndPos,i); $.a|ae|K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5C B%=iL{
fileSplitterFetch.start(); g92dw<$>
} p'}lN|"{O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u#FXW_-TK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vevf[eO-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4f!dYo4L
nEndPos = " + nFileLength); N+NK`
// fileSplitterFetch[nPos.length-1].start(); BhLZ7*
6GzzGP^
ojoxXly`
//等待子线程结束 4`s)ue
//int count = 0; `y2ljIWJ
//是否结束while循环 \#++s&06
boolean breakWhile = false; &U&Zo@ot"x
(xL :;
ailG./I+
while(!bStop) +#~O'r]%GG
{ j{)~QD?
write_nPos(); jB!W2~Z
Utility.sleep(500); ZOuR"9]
breakWhile = true; eQ<xp A
&Pq\cNYzW
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for(int i=0;i<nStartPos.length;i++) G?<pBMy
{ LJWTSf"f?
if(!fileSplitterFetch.bDownOver) B7!;]'&d
{ frc{>u~t
breakWhile = false; uf]Y^,2
break; VHW`NP 5Jl
} ,E?4f @|X
} .fEwk
if(breakWhile) Ukc'?p,*
break; <(YF5Xm6$h
IcFK,y%1
akC>s8tqlA
//count++; )Oievu_"|
//if(count>4) b+Vi3V
// siteStop(); \i0-o8q@I
} A*F9\mjI5
E~RV1)
Sph*1c(R
System.err.println("文件下载结束！"); hM>*a!)U
} =/Wu'gG)
catch(Exception e){e.printStackTrace ();} VjB*{,
} kwlC[G$j7
.!yq@Q|=u
4fty~0i=z
//获得文件长度 DWrbp
public long getFileSize() ]_u`EvEx6
{ YBvd q1
int nFileLength = -1; o@3B(j;J`
try{ q5p e~
URL url = new URL(siteInfoBean.getSSiteURL()); ,dcg?48
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eu9w|g
httpConnection.setRequestProperty("User-Agent","NetFox"); X`1p'JD
Q>=-ext}q
*H"aOT^{
int responseCode=httpConnection.getResponseCode(); fK_~lGY(
if(responseCode>=400) ;Iq5|rzDn
{ 6m+W#]^
processErrorCode(responseCode); [))JX"a
return -2; //-2 represent access is error lR@& Z6lw
} W2<3C
! =WcF5
H)5QqZ8
String sHeader; ,QvYTJ{
F7T E|LZ
TatMf;?h&
for(int i=1;;i++) KO&:06V{
{ H&bh<KPMh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7/"@yVBW
//Utility.log(in.readLine()); yp+F<5o
sHeader=httpConnection.getHeaderFieldKey(i); P}@*Z>j:#
if(sHeader!=null) N09KVz2Q
{ =dGKF`tR
if(sHeader.equals("Content-Length")) -:SIS`0s
{ El (/em
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PN &|8_
break; azX`oU,l
} $XGtS$
} 0T))>.iu#
else <hv7s,i
break; lFfXWNb
} Dm%%e o
} s.:r;%a
catch(IOException e){e.printStackTrace ();} 2-mQt_ i
catch(Exception e){e.printStackTrace ();} # X/Q
E[?kGR[
_{Y$o'*#I
Utility.log(nFileLength); T3z(k la
yM ,VrUh
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return nFileLength; jczq`yW
} sRq U]i8l
o56kp3b)b
w$>3pQ8d
//保存下载信息（文件指针位置） jBpVxv
private void write_nPos() 3cC }'j
{ /DO'IHC.o
try{ Rla4L`X;
output = new DataOutputStream(new FileOutputStream(tmpFile)); kcS6_l
output.writeInt(nStartPos.length); M<(u A'
for(int i=0;i<nStartPos.length;i++) *jF#^=
{ $Nu)E
// output.writeLong(nPos); !O{z 3W
output.writeLong(fileSplitterFetch.nStartPos); <HQ&-jx
output.writeLong(fileSplitterFetch.nEndPos); R1'`F{56
} ?N>pZR
output.close(); :;4SQN{2 O
} yvxl_*Ds8
catch(IOException e){e.printStackTrace ();} A5XR3$5P
catch(Exception e){e.printStackTrace ();} r1Z<:}ZwK
} r)b<{u=]
*]x_,:R6Ow
a)S7}0|R
//读取保存的下载信息（文件指针位置） O<GF>
private void read_nPos() O >FO>
{ 2-v\3voN
try{ RH1uVdJ1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YwAnqAg
int nCount = input.readInt(); kon=il<@
nStartPos = new long[nCount]; p)/ p!d[T/
nEndPos = new long[nCount]; 'qy#)F
for(int i=0;i<nStartPos.length;i++) 0x5xLg;Q
{ o.^y1mH'
nStartPos = input.readLong(); bx>i6 R2
nEndPos = input.readLong(); \ e,?rH
} DB@EVH
input.close(); ]0/p 7N14
} ]MAT2$"le
catch(IOException e){e.printStackTrace ();} A*'V+(
catch(Exception e){e.printStackTrace ();} ;fGx;D
} U)[ty@zyF
Ror2qDF
LC-)'Z9}5
private void processErrorCode(int nErrorCode) R0<< f]
{ U:|H9+5
System.err.println("Error Code : " + nErrorCode); J&6:d
} BXhWTGiG
o~C('1Fdb
ez*jjm
//停止文件下载 iP "EA8
public void siteStop() ( v@jc8y
{ VJ{pN~_1
bStop = true; n )K6i7]xk
for(int i=0;i<nStartPos.length;i++) \!H{Ks{#R.
fileSplitterFetch.splitterStop(); &qRJceT(
~m`!;rE
"l,UOv c
} =!,Gst_
} 9;KJr[FQV
//负责部分文件的抓取 .Z%G@X*
**FileSplitterFetch.java >;nS8{2o
*/ 0H:dv:#WAI
package NetFox; f=I:DkR
~O4|KY
C5n?0I9
import java.io.*; ',mW`ZN
import java.net.*; S()Za@ [a$
)|]Z>>%t
)+Y&4Qu
public class FileSplitterFetch extends Thread { (ZPXdr
7ZFJexN]
Z$;"8XUM
String sURL; //File URL {L0;{
long nStartPos; //File Snippet Start Position ^?"^Pmw
long nEndPos; //File Snippet End Position ;V.vfar
int nThreadID; //Thread's ID r4;Bu<PQN1
boolean bDownOver = false; //Downing is over !T'X 'Q
boolean bStop = false; //Stop identical 0"4@;e_)>
FileAccessI fileAccessI = null; //File Access interface 7Dt"]o"+
;NsO
vWY(%Q,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cZQu*K^j
{ *gu8-7'
this.sURL = sURL; m0( E kK
this.nStartPos = nStart; #Lka+l;L7
this.nEndPos = nEnd; dr})-R
nThreadID = id; o&-L0]i|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 40K2uT{cq
} <NB41/
-(;LQDG |
/EFq#+6
public void run() c8DZJSO
{ `ROEV~
while(nStartPos < nEndPos && !bStop) K.DXJ UR
{ WC-_+9)2&
vJCf~'
t ;-L{`mW
try{ s AE9<(g&@
URL url = new URL(sURL); )=H{5&e#u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^M Ey,
httpConnection.setRequestProperty("User-Agent","NetFox"); 'G#SLqZy
String sProperty = "bytes="+nStartPos+"-"; A=`*r*
httpConnection.setRequestProperty("RANGE",sProperty); <qY5SV,
Utility.log(sProperty); F?4Sz#
;^-:b(E
xP@/9SM
InputStream input = httpConnection.getInputStream(); r nBOj#N
//logResponseHead(httpConnection); >XE`h9
,w`~K:b.
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byte[] b = new byte[1024]; aRwnRii
int nRead; f7+Cz>R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (9GbG"
{ ./w{L"E
nStartPos += fileAccessI.write(b,0,nRead); Hj~O49%j&
//if(nThreadID == 1) 9<cOYY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I;j3*lV_
} ^ d\SPZ
E`AYee%l
3N<&u
Utility.log("Thread " + nThreadID + " is over!"); }kPVtSQ
bDownOver = true; 25em[Q:
//nPos = fileAccessI.write (b,0,nRead); 4lz{G*u
} frH)_YJ%
catch(Exception e){e.printStackTrace ();} wkikD
} qrDcL>Hrn
} `&g:d E(j
1xTTJyoq
\A(5;ZnuD
//打印回应的头信息 gaeOgP.0
public void logResponseHead(HttpURLConnection con) ,- HIFbXx@
{ +X^4; &
for(int i=1;;i++) MsjnRX:c3u
{ WK;(P4Z
String header=con.getHeaderFieldKey(i); 4}-#mBV]/
if(header!=null) &jm[4'$ *z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yXF|Sqv
Utility.log(header+" : "+con.getHeaderField(header)); KO,_6>8]U
else 295w.X(J
break; 4VFc|g
} OCW+?B;
} Qp!J:YV
o}~3JBnT
yWHne~!
public void splitterStop() X47Ol
{ V2Y$yV8g1
bStop = true; mo9$NGM&}
} ;0j*>fb\q7
cht
3h&bZ
} K-4tdC3
!6E:5=L^
d@>\E/zA
/* }ywi"k4>
**FileAccess.java ,qy&|4Jz
*//文件访问(定位，写) uaxB -PZ
package NetFox; E@pFTvo
import java.io.*; 1nB@zBQu-
sqG`"O4W
DHzkRCM
public class FileAccessI implements Serializable{ kfCKhx
EUZq$@uWL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bi,mM,N/
RandomAccessFile oSavedFile; l* Y[^'
long nPos; |<Bpv{]P
0N VI+Z$
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public FileAccessI() throws IOException KjYDFrR4
{ ,?y7,nb
this("",0); }vD;DSz:
} GP]TnQ<*;
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rfTe
public FileAccessI(String sName,long nPos) throws IOException XnY"oDg^>
{ o?dR\cxj
oSavedFile = new RandomAccessFile(sName,"rw"); Wp4K6x
this.nPos = nPos; & rQD`E/
oSavedFile.seek(nPos); |EeBSRAfe
} wlVvxX3%
s3< F
.. UoyBV
public synchronized int write(byte[] b,int nStart,int nLen) M=+M8M`Iy
{ 7jT}{ x
int n = -1; hVZo"XUb
try{ JUU&Z[6J
oSavedFile.write(b,nStart,nLen); ohplj`X[21
n = nLen; 6Ahr_{
} 7TdQRB
catch(IOException e) 6 [ _fD
{ G>0)I
e.printStackTrace (); KpGUq0d@
} 8^T2^gs
UoRDeYQ`E
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return n; i;]CL[#2e`
} {Zwf..,
B^m!t7/,
.C?GW1[c~@
} uk6g s)qxC
$WClpvVj
-t>Z 9
/* M8_R
**SiteInfoBean.java hr1$1&p
*/ R8uj3!3^
package NetFox; `WlH*p)z9
kF2Qv.5!
j"6:A
public class SiteInfoBean { Gc^t%Ue-H)
G1p'p&x.
]b)!YPo
private String sSiteURL; //Site's URL DO%Pwfkd
private String sFilePath; //Saved File's Path tj0Qr-/
private String sFileName; //Saved File's Name Y"oDFo,
private int nSplitter; //Count of Splited Downloading File U/5$%0)
K=o:V&
AZBC P
public SiteInfoBean() OA5f}+
{//nSplitter的缺省值为5 %-r?=L
//default value of nSplitter is 5 XLocg
this("","","",5); ^k;mn-0
} 1b+h>.gWar
b-4dsz'ai
\*J.\f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1x;@~yU
{ 1=>2uYKR
sSiteURL= sURL; Qpw@MF2P
sFilePath = sPath; 22'vm~2E
sFileName = sName; &L'6KEahR
this.nSplitter = nSpiltter; 6Wb!J>93
_[%n ~6
nUqL\(UuY
} ?cJA^W
]7l{g9?ZtV
(QKsB3X
public String getSSiteURL() SlN"(nq
{ ,@479ZvvR3
return sSiteURL; T,Fm"U6[(
} `OBl:e
fOLnK y#
W W35&mI)k
public void setSSiteURL(String value) F#KF6)P
{ }Q;BQ2[
sSiteURL = value; G}q<{<+$
} q55M8B 4w
yH+c#w
}EP|Mb
public String getSFilePath() I<KCt2:X
{ ovSH}h!
return sFilePath; @x*.5:[
} df yrn%^Ia
_}^u-fJ/~
3jS7 uU
public void setSFilePath(String value) &rcdr+'
{ ~9bv Wd1D
sFilePath = value; 2=O))^8
} {F/q{c~]
\ JG #m
<ipWMZae0F
public String getSFileName() 9LHa&""
{ d&?F#$>7|
return sFileName; \D ^7Z97
} moe/cO5a9
N|o>%)R
;)P5#S!n-
public void setSFileName(String value) =CEHRny
{ JC/d:.
sFileName = value; !L/tLHk+
} y{?Kao7Ij
N?zV*ngBS
@??u})^EL
public int getNSplitter() OFp#<o,p
{ $8=(I2&TW
return nSplitter; my]P_mE
} hj+p`e S
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wzg i @i
public void setNSplitter(int nCount) K` 2i
{ 16L"^EYq
nSplitter = nCount; Vl-D<M+ih
} ;tm3B2
} zWJKYFqK
~PCTLP~zI
2nJYS2mT7
/* x~%\y
**Utility.java &hO$4qtN
*/ 0:jsV|5B8
package NetFox; =I7[L{+~Y
? 1GJa]G
TX&[;jsj
public class Utility { sFCf\y
K[n<+e;G
\Ec X!aC
public Utility() |I(%7K
{ X"wFQa
vu44!c@
1T:)Zv'
} ?l(nM+[kSL
z"9aAytd
//线程睡眠 1]HHe*'Z
public static void sleep(int nSecond) Un]DFu
{ 6<#Slw[
try{ V,E9Uds
Thread.sleep(nSecond); *Gf&q
} =Z^un&'
catch(Exception e) )eVzSj>MT
{ zI(xSX@
e.printStackTrace (); 5[1@`6j
} ixg\[5.Q+
} vs*>onCf
*13g<#$
//日志 u4@, *tT
public static void log(String sMsg) .[#xQ=9`
{ K6ciqwUO
System.err.println(sMsg); YcPKM@xo
} -?[O"D"c
Tq.MubaO
$ V3n~.=
public static void log(int sMsg) y/z9Ce*>
{ p!C_:Z5i
System.err.println(sMsg); xP XoJN
} {`($Q$Q1
} QziN]
Y!bpOa&
g9M')8a n
/* b$PT_!d
**TestMethod.java C3]\$
*/ K<D`(voL
package NetFox; lp?i_p/z
8.:B=A
!Jk(&.
public class TestMethod { MiRibHXI,
fLLnf].O
y?[5jL|Ue
public TestMethod() pM1=UF
{ ///xx/weblogic60b2_win.exe od;Bb
try{ d&O'r[S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #($k 3OA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oXnC"y}0P
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3| GNi~
fileFetch.start(); ,w,ENU0~f
} ^qE<yn
catch(Exception e){e.printStackTrace ();} '#;,oX~5
[Od>NO,n+]
38Bnf
} 4x=V|"
Pn~pej5'K
p7%0hLW
public static void main(String[] args) nh _DEPMq
{ Ry3+/]
new TestMethod(); ORUWslMt
} Bu*W1w\
} a7ub.9>
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