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)); V8pZr+AJ
} G2sj<F=AV
for(int i=0;i<nEndPos.length-1;i++) <<Z, 1{3F
{ %z~kHL
nEndPos = nStartPos[i+1]; ?1LRR ;-x
} 0xeY0!ux
nEndPos[nEndPos.length-1] = nFileLength; e;|$nw-
} #D ]CuSi
} v5{2hCdt
+A$>F@u
.F$cR^i5u
//启动子线程 .Ep&O#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y%}N@ ,lT
for(int i=0;i<nStartPos.length;i++) I;G(Wj
{ `9T5Dem|#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'C>sYSL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bu08`P9
nStartPos,nEndPos,i); fILvEf4b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qN Ut&#
fileSplitterFetch.start(); H_aG\
} W|s";EAM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pEW~zl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ovi^bNQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RU>qj *e
nEndPos = " + nFileLength); > +00[T
// fileSplitterFetch[nPos.length-1].start(); 59+KOQul6
>Ml5QO$*.q
47f\
//等待子线程结束 (S?DKPnR
//int count = 0; A<(DYd1H
//是否结束while循环 B$hog_=s
boolean breakWhile = false; Ji6.-[:
~_g{P3
R-wz+j#
while(!bStop) ^r mQMjF
{ ~-R2mAUK
write_nPos(); pmO0/ty
Utility.sleep(500); "7jE&I
breakWhile = true; l/\D0\x2
Q7tvpU
a(ml#-M
for(int i=0;i<nStartPos.length;i++) tE-g]y3
{ N0JdU4'
if(!fileSplitterFetch.bDownOver) Tf?`_jL
{ yO*
breakWhile = false; |k,-]c;6
break; 1-&L-c.
} XP?)xDr8
} KDH<T4#x
if(breakWhile) brlbJFZ19
break; Xil;`8h
.0~uM!3y
~-B+7
//count++; Nd{U|k3pL
//if(count>4) 7q5*grm
// siteStop(); YhqMTOw
} U4yl{?
M CP GDr
e0otr_)3F
System.err.println("文件下载结束！"); 1xkrhqq
} D{[{&1\)r
catch(Exception e){e.printStackTrace ();} 4z9lk^#"X
} X8N9*vy
`u PLyS.
VxARJ*4=Y
//获得文件长度 FouN}X6
public long getFileSize() #.$y
{ \<09.q<8
int nFileLength = -1; B&0W P5OF
try{ ^w2 HF
URL url = new URL(siteInfoBean.getSSiteURL()); cO5zg<wF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !\9^|Ef?
httpConnection.setRequestProperty("User-Agent","NetFox"); 22U`1AD3U
j0V/\Ep)T<
QCE7VV1Rw
int responseCode=httpConnection.getResponseCode(); Pnm$g;`P
if(responseCode>=400) IF\ @uo`
{ i1-%#YYF(
processErrorCode(responseCode); CH 29kQ
return -2; //-2 represent access is error 2Q5@2jT
} 8&| o
't0M+_J
L/`1K_\l
String sHeader; :zLf~W
f5FEHyj|
LdN[N^n[H
for(int i=1;;i++) 1gbFl/i6T
{ MGt>:&s(]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $T^q>v2u
//Utility.log(in.readLine()); Qz#By V:
sHeader=httpConnection.getHeaderFieldKey(i); ZDgT"53
if(sHeader!=null) 'wG1un;t
{ dIlpo0; F
if(sHeader.equals("Content-Length")) !]82$
{ #S'uqP!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hr6j+p:
break; VN!nef
} orH6R8P]
} J&,hC%]
else QOSMV#Nw%
break; J 3C^tV
} )`f-qTe
} $["HC-n?.k
catch(IOException e){e.printStackTrace ();} W/>a 1
catch(Exception e){e.printStackTrace ();} kaB|+U9^
Hy&Z0W'l
c&',#.9
Utility.log(nFileLength); pTwzVz~
&um++ \
t~/:St
return nFileLength; cr{yy :D
} #NYnZ^6e
`hkvxt
,#3Aaw
//保存下载信息（文件指针位置） |<,qnf| -
private void write_nPos() 8xgBNQdPT
{ [1P_^.Htr
try{ WF~BCP$OR
output = new DataOutputStream(new FileOutputStream(tmpFile)); aO&{.DO2
output.writeInt(nStartPos.length); 1bCE~,tD
for(int i=0;i<nStartPos.length;i++) _Fa\y ZX
{ y 2> 93m
// output.writeLong(nPos); bXF8V
output.writeLong(fileSplitterFetch.nStartPos); 9u{[e"
output.writeLong(fileSplitterFetch.nEndPos); .eD&UQ
} -EP1Rl`\
output.close(); K9%rr_ja!
} 0j!3\=P$
catch(IOException e){e.printStackTrace ();} /g{*px|
catch(Exception e){e.printStackTrace ();} ;7:} iKU
} ;QXg*GNAv$
IeYNTk&<
C`i#7zsH
//读取保存的下载信息（文件指针位置） 8fP2qj0
private void read_nPos() @u9L+*F
{ ~iH a^i?2*
try{ |> STb\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *mp:#'
int nCount = input.readInt(); JT0j2_*Rr
nStartPos = new long[nCount]; L.'61ZU
nEndPos = new long[nCount]; q@bye4Ry%W
for(int i=0;i<nStartPos.length;i++) (x2?{\?
{ TF:'6#p
nStartPos = input.readLong(); ';FJs&=I
nEndPos = input.readLong(); :KO&j"[
} <?7qI85OT
input.close(); g,JfT^
} z)C/U
catch(IOException e){e.printStackTrace ();} G]rY1f0
catch(Exception e){e.printStackTrace ();} Gb`)d
} RQ8d1US
j_sos%-
1}wDc$O
private void processErrorCode(int nErrorCode) #9|&;C5',!
{ cgrSd99.
System.err.println("Error Code : " + nErrorCode); $~FZJ@qa
} <WIIurp
b=lJ`|
R*:$^v@4
//停止文件下载 ~ q-Z-MA
public void siteStop() uG7]s]Wdz;
{ K-k!':K:
bStop = true; PSq?8.
for(int i=0;i<nStartPos.length;i++) >b2!&dm
fileSplitterFetch.splitterStop(); >p-UQc
Mrrpm%Y
8C3oi&av/{
} iRrUIWx
} I^k&v V
//负责部分文件的抓取 EX_j|/&tZ
**FileSplitterFetch.java IzTJ7E*i
*/ ZXb|3|D
package NetFox; {`SMxDevc}
9DA|;|
gJ|#xZ
import java.io.*; >} 2C,8N
import java.net.*; ;VKWY
&233QRYM
nUj`#%
public class FileSplitterFetch extends Thread { 0L/chP
]\^O(BzB
As46:<!2
String sURL; //File URL q3#[6!
long nStartPos; //File Snippet Start Position Im~DK
long nEndPos; //File Snippet End Position ]?(kaNQ"D
int nThreadID; //Thread's ID ^ l#6Es
boolean bDownOver = false; //Downing is over o~XK*f=(
boolean bStop = false; //Stop identical 5/nL[4Z
FileAccessI fileAccessI = null; //File Access interface .*`^dt
nBk&+SN
^(:~8 h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *90dkJZ.
{ '/xynk%)xw
this.sURL = sURL; >ZkL`!:s
this.nStartPos = nStart; 5?$MZaT
this.nEndPos = nEnd; Q8`V0E\~
nThreadID = id; o_Zs0/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x"q]~u<rB
} TQck$&
cV6H!\
=%~- M
public void run() ) Z3KO
{ nV8'QDQ:Al
while(nStartPos < nEndPos && !bStop) fd *XK/h
{ s\mA3t
By@65KmR"
=,zB|sjn
try{ CsZm8oL$
URL url = new URL(sURL); 0M;g&&mF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eQuw uT
httpConnection.setRequestProperty("User-Agent","NetFox"); +&7V@
String sProperty = "bytes="+nStartPos+"-"; P0m9($JBD
httpConnection.setRequestProperty("RANGE",sProperty); !Np7mv\7
Utility.log(sProperty); 2z !05]B%
VLm\PS
QP\:wi
InputStream input = httpConnection.getInputStream(); _fk}d[q0
//logResponseHead(httpConnection); X(/fE?%;
Fb1<Ic#
X[.%[G|oj}
byte[] b = new byte[1024]; H_f8/H
int nRead; # l9VTzi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +#wVe
{ Nsh/
nStartPos += fileAccessI.write(b,0,nRead); czIEkm
//if(nThreadID == 1) qZ!kVrmg&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {,5.svO
} mQ1
C _he=SV
hkl0N%[
Utility.log("Thread " + nThreadID + " is over!"); &v0]{)PO
bDownOver = true; %pjY^tM/
//nPos = fileAccessI.write (b,0,nRead); 5rLx b
} Vq0X:<9
catch(Exception e){e.printStackTrace ();} (pCHj'
} $s=` {vv
} W3[>IH"+
7ucm1
axmq/8X
//打印回应的头信息 neu<zSS
public void logResponseHead(HttpURLConnection con) TI8\qIW
{ ">=Ep+ix
for(int i=1;;i++) L *\[;.mk
{ GmNCw5F
String header=con.getHeaderFieldKey(i); .*6NqX$
if(header!=null) }ACg#;>/+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }.D18bE(
Utility.log(header+" : "+con.getHeaderField(header)); fr`#s\JKw
else #@-dT,t
break; <=_!8A
} dpE^BWv3
} ,5<AV K-#Q
VXZYRr3F
yz0#0YG7
public void splitterStop() M*n94L=Sg&
{ 7./-|#
bStop = true; v$@1q9 5J
} ,#BD/dF
4xT /8>v2|
WYRC_U7
} @?J7=}bzz
&Oz
-wH0g^Ed
/* bbS,pid1
**FileAccess.java :Nf(:D8
*//文件访问(定位，写) j*gZvbO;'L
package NetFox; VDv.N@)7
import java.io.*; fzVN;h
&b,A-1`w_
f uU"
public class FileAccessI implements Serializable{ s+_8U}R
+68age;dM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9G6ZKqum
RandomAccessFile oSavedFile; POc<XLZB
long nPos; ze9n}oN
W\0u[IV.x
,>qtnwvlHP
public FileAccessI() throws IOException m4uh<;C~
{ -#;ZZ\fdj
this("",0); v1+.-hO
} ^^ SMr l
dg*xo9Xi`
O%bltNEx1
public FileAccessI(String sName,long nPos) throws IOException =n=!s{A:t
{ R)N^j'R~=
oSavedFile = new RandomAccessFile(sName,"rw"); rFt+Y})
this.nPos = nPos; S{F\_'%
oSavedFile.seek(nPos); \I6F;G6
} =B+dhZ+#S$
XmwR^
3HR)H-@6@7
public synchronized int write(byte[] b,int nStart,int nLen) c3rj :QK6I
{ c*axw%Us
int n = -1; =],c$)
try{ bhg6p$411
oSavedFile.write(b,nStart,nLen); bM_fuy55Op
n = nLen; +7lr#AvU/
} =d~pr:.F
catch(IOException e) #/9Y}2G|]
{ o&k,aCQC
e.printStackTrace (); >D##94PZ
} #ax% n
~z41$~/
DuAix)#FN9
return n; N5#j}tT
} /IX555/dR1
v13\y^t
n^55G>"0|
} 'tQp&pj
E)p[^1WC
nnu#rtvZp}
/* 48;b
**SiteInfoBean.java M0vX9;J
*/ 9,tk
package NetFox; w!d(NA<|0]
nemC-4}
!-SI &qy
public class SiteInfoBean { g38MF
Mbly-l{|
v$;URF%^
private String sSiteURL; //Site's URL 7''iT{-[p
private String sFilePath; //Saved File's Path #'i,'h+F
private String sFileName; //Saved File's Name B'y)bY'_dS
private int nSplitter; //Count of Splited Downloading File X}QcXc.d
0E3;f;'X
'['x'G50
public SiteInfoBean() I~ mu'T
{//nSplitter的缺省值为5 va#].4_
//default value of nSplitter is 5 VGCd)&s
this("","","",5); )T slI
} 3:OqD~,zy
O ~[[JAi[
( YZ2&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vMJ_n=Vf
{ c|iTRco
sSiteURL= sURL; rof9Rxxe-
sFilePath = sPath; Z;dR:|%)
sFileName = sName; 3^)c5kcI
this.nSplitter = nSpiltter; #>z!ns
@y eAM7
),%@X
} OzTR#`oey
r'*#i>PkQD
M,r8 No
public String getSSiteURL() NXS$w{^
{ Cs vwc%
return sSiteURL; p7.~k1h
} :$XlYJrjK
|$GPJaNqa
BISH34
public void setSSiteURL(String value) ( ~JtKSq%
{ XHJ/211
sSiteURL = value; h54\ \Ci
} + :b"0pu-H
1:{+{Yl7
W6u(+P]("
public String getSFilePath() |b!Bb<5
{ M~9IL\J^G
return sFilePath; Hm~.u.)\.
} }JUc!cH8z
po*r14f
Gy'/)}}Z
public void setSFilePath(String value) =6qSo @
{ I5Rd~-="G
sFilePath = value; +\.0Pr
} H.tfn>N|
{{ 1qkG9$
!Okl3 !fC
public String getSFileName() rF/<}ye/4M
{ J8&0l&~6
return sFileName; 8K\S]SZ
} 3Z}KRsp3
y XCZs
;_/!F}d
public void setSFileName(String value) uPb.uG
{ ,jy9\n*<t9
sFileName = value; qMd4awB R
} bhW&,"$Z
TH~"y
0"mr*hyj
public int getNSplitter() - G=doP0
{ mU>lm7'
return nSplitter; D@ BP<
} Ed#Hilk'
Z3dI B`@
}~v0o# I
public void setNSplitter(int nCount) LiEDTXRz
{ PJ)d5D%T
nSplitter = nCount; UrdSo"%
} OXV9D:bIa
} (%4O\s#l
.ITTYQHv)
{YIVi:4q
/* *3y_FTh8ra
**Utility.java [-nPHmZV[
*/ I%mGb$Q
package NetFox; tG0 &0`
6D4 j];~X
Bdib)t[
public class Utility { z2;<i|Ez0
PWS5s^WM
'.XR,\g>
public Utility() 4BJw+EV8
{ =^w:G=ymS
M{X; H'2
vZ|Wj] ;o
} ^B(:Hv}G(:
t28 y=nv
//线程睡眠 TcH7!fUj
public static void sleep(int nSecond) 88zK)k{
{ ^:ehG9
try{ &hIr@Gi@ch
Thread.sleep(nSecond); a=*JyZ.2
} nO8e'&|
catch(Exception e) Az6tu <
{ `m-7L
e.printStackTrace (); |p*s:*TJp
} Y-]Ne"+vf
} b5l;bXp]
v<gve<]
//日志 35~1$uRA
public static void log(String sMsg) =u.hHkx
{ v.>95|8
System.err.println(sMsg); +wm%`N;v<
} *YP;HL
A7aW]
k}e~xbh-y
public static void log(int sMsg) W>E|Iv[o
{ q)y<\cEO
System.err.println(sMsg); #M[%JTTn
} R(#ZaFuo[
} 5:SS2>~g
gO_d!x*
<!PbD
/* US]I[Y6V
**TestMethod.java h:<?)g~U
*/ b4>1UZGW-
package NetFox; bfKF6
A_I\6&b4
\T^ptj(0
public class TestMethod { luCwP
oN=>U"<\1
hfRxZ>O2
public TestMethod() |) CfO4
{ ///xx/weblogic60b2_win.exe e9rgJJ
try{ u56WB9Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jL:GP}I=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G@o\D-$
SiteFileFetch fileFetch = new SiteFileFetch(bean); __,F_9M
fileFetch.start(); '_FxxLAO
} 1( rN
catch(Exception e){e.printStackTrace ();} :} DTK
Pk&sY'
>yqFO
} r)[Xzn
#?7g_
,7SqRY,+
public static void main(String[] args) af}JS2=$
{ P$&l1Mp
new TestMethod(); *)s^+F 0
} %8?XOkH)
} {Hzj(c~S?
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