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)); LE;g 0s
} 6 hiC?2b{x
for(int i=0;i<nEndPos.length-1;i++) +>YfRqz:KB
{ 5 9-!6;T
nEndPos = nStartPos[i+1]; PC/!9s0W
} yV]xRaRr2
nEndPos[nEndPos.length-1] = nFileLength; R$6qoqv{yG
} }5bM1h#z
} +nU.p/cK+\
3-x%wD.
w*~Tm>U
//启动子线程 [m2+9MMl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o4Q3<T7nI
for(int i=0;i<nStartPos.length;i++) oH-8r:{
{ 9l !S9d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C}"@RHEu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?<~WO?
nStartPos,nEndPos,i); MCnN^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p^X^1X7
fileSplitterFetch.start(); x"\qf'{D
} Pil;/t)"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I>n g`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &<1`O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F ?=9eISLJ
nEndPos = " + nFileLength); !%S4n
// fileSplitterFetch[nPos.length-1].start(); }ugxN0
d2jr8U
5*G%IR@@LK
//等待子线程结束 Qv{,wytyO
//int count = 0; >*qQ+_
//是否结束while循环 m*n5zi|O
boolean breakWhile = false; @Icq1zb] y
{fz$Z!8-
`W5-.Tv
while(!bStop) h;M3yTM-
{ IeTdN_8
write_nPos(); jw>hk
Utility.sleep(500); jk70u[\
breakWhile = true; S/gm.?$V
nhH;?D3
]U_ec*a
for(int i=0;i<nStartPos.length;i++) ^T079=$5
{ \}dyS8
if(!fileSplitterFetch.bDownOver) ZYMw}]#((E
{ s3 B'>RG}
breakWhile = false; Ge \["`;i
break; 6/Y1 wu
} p>kq+mP2bc
} FFcB54ALTf
if(breakWhile) hIU(P Dl4
break; .6.^G
P&=lV}f
npH?4S-8G
//count++; aC^$*qN-)
//if(count>4) ~5OL6Bi-q
// siteStop(); YpmYxd^
} HW6.O|3
..qd,9H
r>n" 51*
System.err.println("文件下载结束！"); a.kbov(
} &ab|2*3?X
catch(Exception e){e.printStackTrace ();} +%#8k9Y
} ;Icixu'O
5<R%H{3j
1W,(\'^R
//获得文件长度 xeA#u J
public long getFileSize() bB6[Xj{
{ C/tr$.2H=
int nFileLength = -1; WUoOGbA `
try{ &M[f&_"8Q
URL url = new URL(siteInfoBean.getSSiteURL()); WES#ZYtT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =r4!V>
httpConnection.setRequestProperty("User-Agent","NetFox"); 8q^o.+9
Uems\I0
sqO<J$tz
int responseCode=httpConnection.getResponseCode(); 7"2b H
if(responseCode>=400) ?M}S|dsmE
{ l-)Bivoi
processErrorCode(responseCode); Q*ju sm
return -2; //-2 represent access is error 9 [Y-M
} C"eXs#A
QMp rv*i
]r/^9XaqtA
String sHeader; p]&j;H.
wij,N(,H
GjT#%GBF
for(int i=1;;i++) FN87^.^2S
{ MDO$m g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PuCc2'#
//Utility.log(in.readLine()); wEEn?
sHeader=httpConnection.getHeaderFieldKey(i); WFv!Pbq,
if(sHeader!=null) ,.mBJSE3
{ }iiHr|l3
if(sHeader.equals("Content-Length")) *3+-W
{ ,/2LY4` 5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `jsEN ;<
break; ERz;H!pU8
} (-^bj
} gS9>N/b|
else WZewPn>#q
break; f`$Gz
} ZI13
} 6NLW(?]
catch(IOException e){e.printStackTrace ();} VLvS$0(}Z
catch(Exception e){e.printStackTrace ();} \ v2H^j/
{6,|IGAq V
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Utility.log(nFileLength); \;9W.d1iU
u=NG6G
-,#+`>w
return nFileLength; -4 Ux,9&
} "IjI'c
`=)2<Ca;~@
r@}bDkx
//保存下载信息（文件指针位置） Jfhk@27T
private void write_nPos() I9 64
{ fg*@<'
try{ DSyXr~p8
output = new DataOutputStream(new FileOutputStream(tmpFile)); X_TiqV
output.writeInt(nStartPos.length); >FF5x#^&c
for(int i=0;i<nStartPos.length;i++) i'HQQWd
{ ;sOsT?)7$
// output.writeLong(nPos); w4};q%OBj
output.writeLong(fileSplitterFetch.nStartPos); 1,t)3;o$
output.writeLong(fileSplitterFetch.nEndPos); _M5%V>HO
} YZwaD b
output.close(); J7$_VP
} /@oLe[Mz$
catch(IOException e){e.printStackTrace ();} n=sXSxl
catch(Exception e){e.printStackTrace ();} 1TN}GsAj
} b{Zpux+
b$JBL_U5Ch
3=.Y,ENM;
//读取保存的下载信息（文件指针位置） On_@HQ/FI
private void read_nPos() B(5c9DI`
{ D]03eu
try{ 't (O$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kuMKX`_
int nCount = input.readInt(); /f{$I
nStartPos = new long[nCount]; U.oksD9v
nEndPos = new long[nCount]; Im72Vt:p-
for(int i=0;i<nStartPos.length;i++) ot%.M*h-
{ 4B[D/kIg
nStartPos = input.readLong(); E1V^}dn
nEndPos = input.readLong(); 7}o/:
} XEH}4;C'{
input.close(); rNN j0zw>
} k5BXirB
catch(IOException e){e.printStackTrace ();} 3'I^lc
catch(Exception e){e.printStackTrace ();} !u|Tu4G^
} lU4}B`#"v
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RYR-K^;R
private void processErrorCode(int nErrorCode) >t+ qe/
{ ^>c8t_RG
System.err.println("Error Code : " + nErrorCode); @tT-JwU
} hsNWqk qys
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Qst$S}n
//停止文件下载 ^4Uw8-/9
public void siteStop() |`O5Xs1{B
{ .TB"eUy
bStop = true; \_]En43mg
for(int i=0;i<nStartPos.length;i++) H=c`&N7E
fileSplitterFetch.splitterStop(); L=!of{4Z(}
NTs7KSgZ
3z =^(Y
} v4vf}.L]
} Gwec4D
//负责部分文件的抓取 @_ygnNn4R
**FileSplitterFetch.java ii|?;
*/ s95F#>dr
package NetFox; m?CZQq,
4mYCSu14:`
:3ZYJW1
import java.io.*; b'p4wE>
import java.net.*; "jg@w%~
+b$S~0n
#CUzuk&
public class FileSplitterFetch extends Thread { QV|>4^1D
1+kE!2b;b
mqtg[~dNc
String sURL; //File URL .8gl< vX
long nStartPos; //File Snippet Start Position !kuX,*}q
long nEndPos; //File Snippet End Position /8ynvhF#
int nThreadID; //Thread's ID QrYa%D+
boolean bDownOver = false; //Downing is over 0JyVNuHn
boolean bStop = false; //Stop identical HM[klH]s=
FileAccessI fileAccessI = null; //File Access interface ]1`g^Z@ 0
"9y( }
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yg|lq9gD
{ lTRl"`@S
this.sURL = sURL; jQs>`P-CM
this.nStartPos = nStart; (#\pQ51
this.nEndPos = nEnd; e)^j+ l
nThreadID = id; }%!tT\8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X*eW#|$\
} w|Cx>8P8@
"?}uQ5f
K!z`
public void run() kQ>^->w
{ w!^~<{Kz
while(nStartPos < nEndPos && !bStop) 9/ovKpY
{ \fWW'
`8_z!)
TYns~X_PR
try{ "h"NW[R
URL url = new URL(sURL); T<b+s#n4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); []kN16F
httpConnection.setRequestProperty("User-Agent","NetFox"); AIijCL
String sProperty = "bytes="+nStartPos+"-"; n| !@1sd
httpConnection.setRequestProperty("RANGE",sProperty); !vD{Df>
Utility.log(sProperty); I~* ? d
N!&:rK
G'z{b$?/[
InputStream input = httpConnection.getInputStream(); =<z.mzqu5
//logResponseHead(httpConnection); {r85l\u)Q\
'\q f^?9
Y'VBz{brf
byte[] b = new byte[1024]; {MdLX.ycc)
int nRead; k0z&v <
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,YYVj{~2
{ 2{,n_w?Wy
nStartPos += fileAccessI.write(b,0,nRead); 9SQ4cv*2
//if(nThreadID == 1) A=5epsB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q%YV$$c
} R,2P3lv1v@
0ZpFE&
(7FW9X;
Utility.log("Thread " + nThreadID + " is over!"); LtgXShp_!
bDownOver = true; 2;3f=$3
//nPos = fileAccessI.write (b,0,nRead); Kn;D?ioY
} #uCB)n&.
catch(Exception e){e.printStackTrace ();} o(kM9G|
} arK_oh0B
} {No L
a`Qot
XM1`x
//打印回应的头信息 qO1tj'U<
public void logResponseHead(HttpURLConnection con) \00DqL(Oj`
{ vxQ8t!-u
for(int i=1;;i++) ~p0c3*
{ una%[jTc
String header=con.getHeaderFieldKey(i); nKr9#JebRC
if(header!=null) Fm_y&7._
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |]=2 }%1w
Utility.log(header+" : "+con.getHeaderField(header)); Q _iO(qu 6
else ti5HrKIw
break; F^$led1/F
} MxQ?Sb%Gka
} [4&#*@
!5@_j,lW(
Os%n{_#8
public void splitterStop() qml2XJ>
{ BQ</g* $;
bStop = true; Z;Rp+X
} G2{O9
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s) O[t
} #EGA#SKoq
,B}I?vN.
fU3`v\X
/* 7}O.wUKw%
**FileAccess.java D#A~Nbc
*//文件访问(定位，写) }ArpPU :]
package NetFox; {Rq1HH
import java.io.*; ~tFqb<n
J T#d(Y
C#;jYBtT7?
public class FileAccessI implements Serializable{ )3<:tV8
o_M.EZO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _Us*+ 2(4L
RandomAccessFile oSavedFile; A=zPLq{Sb
long nPos; 2L_6x<u'
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gd/H``x|Y
public FileAccessI() throws IOException #%@*p,xh
{ nwt C:*}
this("",0); 1_'? JfY-
} jVgFZ,
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1'v5/
public FileAccessI(String sName,long nPos) throws IOException =VLS/\A
{ XZNY4/25G
oSavedFile = new RandomAccessFile(sName,"rw"); -m= 8&B
this.nPos = nPos; m9}AG Rj
oSavedFile.seek(nPos); DmVP
} GV6K/T:
p}b/XnV$~
pg+[y<B
public synchronized int write(byte[] b,int nStart,int nLen) wu9=N ^x
{ 5BkV aF7Th
int n = -1; *1Z5+uVT[
try{ y7i%W4
oSavedFile.write(b,nStart,nLen); FSuAjBl0-
n = nLen; iJxQB\x
} h0Z{,s}
catch(IOException e) g$:Xuw1
{ m4E)qCvy
e.printStackTrace (); 88"Sai
} ]{~NO{0@Y
[[~w0G~1
g42)7
return n; `cQo0{xK
} F 09DV<j
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:4S%'d7
} ZR v"h/~
RC|!+TD
IPSF]"}~
/* Wjh/M&,
**SiteInfoBean.java f~OU*P>V@
*/ Xb !MaNm)
package NetFox; P #F=c34u
vzel#
Y!q!5Crfi
public class SiteInfoBean { -V"22sR]
K ]OK:hY4
Uawpfgc}
private String sSiteURL; //Site's URL "N:XzG
private String sFilePath; //Saved File's Path lJP1XzN_
private String sFileName; //Saved File's Name @;xMs8@
private int nSplitter; //Count of Splited Downloading File yL^UE=#C_
+(D$9{y
"1q>At
public SiteInfoBean() $P7iRM]
{//nSplitter的缺省值为5 &0TVi
//default value of nSplitter is 5 :M{Y,~cP
this("","","",5); qzw'zV
} iGDLZE+?
cH-@V<
]{ BEr*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0,s$T2
{ bb42v7?
sSiteURL= sURL; 7J28JK
sFilePath = sPath; n26Y]7N
sFileName = sName; Kz<@x`0
this.nSplitter = nSpiltter; 8By,#T".
&Lt[WT$
ultG36.x
} \7MHaQvS
GBFw+v/|4
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public String getSSiteURL() S|rgCh!h
{ Dlo xrdOY&
return sSiteURL; DcIvhBp
} B{oU,3U>
to8X=80-3
JxLf?ad.
public void setSSiteURL(String value) TvNY:m6.%
{ >3:?)
sSiteURL = value; kpbm4t
} fl Jp4-nx
KV|}#<dD
=z{JgD/
public String getSFilePath() +5.t. d
{ ri C[lB
return sFilePath; \ 6EKgC1
} LAx4Xp/
1iL'V-y
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public void setSFilePath(String value) Et"?8\"n7
{ zJM S=r
sFilePath = value; Sx*oo{Kk%
} "'^4*o9
04J}UE]Ww
2#X4G~>#h
public String getSFileName() Hv]7e|
{ E@a3~a
return sFileName; _8}QlT
} zJ+8FWy:S
,U)"WLmY
Kx"<J@
public void setSFileName(String value) %8aC1x
{ ,:Vm6u!
sFileName = value; 4RKW
} iDl;!b&V.
N3t0-6$_
o }Tz"bN
public int getNSplitter() E6Rz@"^XV
{ sfr(/mp(
return nSplitter; iFSJL,QZ3
} D2YZ9e
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41#w|L \
public void setNSplitter(int nCount) %or,{mmiM:
{ .%'(9E
nSplitter = nCount; ES<1tG
} GN#<yv$av
} "I;C;}!
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>$gG/WD?KR
/* c4e_6=Iv
**Utility.java -K(fh#<6KO
*/ pqvOJ#?Q}=
package NetFox; gIR^)m
r _,_5 @0e
|W$DVRA
public class Utility { $d+DDm1o
nfb]VN~(
It_M@
public Utility() @=w<B4L
{ `=#01YX[0
a m-b!l!q^
53QfTP
} 2:}fe}
QQk{\PV
//线程睡眠 U(&oj e
public static void sleep(int nSecond) y#Ht{)C
{ \&V0vN1
try{ c~A4gtB=
Thread.sleep(nSecond); ~5ZvOX6L2
} zJa)*N
catch(Exception e) "Th$#3
{ , xx6$uZ
e.printStackTrace (); ?%Rw(E
} |eoid?=
} s"=6{EVqk3
?3z-_8#
//日志 ;TQf5|R\K
public static void log(String sMsg) qZ@0]"h
{ *fO3]+)d+
System.err.println(sMsg); 8T;IZ(s
} VS#wl|b8
QYXx:nIrg
I~PDaZP
public static void log(int sMsg) B}OY/J/*8
{ Gx?+9CV
System.err.println(sMsg); DPe]daF
} +c:3o*
} 4A{|[}!
nU+tM~C%a
g}&hl"j
/* k.h`Cji@
**TestMethod.java W-RqN!snJ8
*/ 8pLBt:
package NetFox; @J[6,$UVu
I3u{zHVwI
M|T4~Q U&
public class TestMethod { "_L?2ta
ci,+Bjc
fkfZ>D^1
public TestMethod() +]>+a<x*%
{ ///xx/weblogic60b2_win.exe 7RU}FE
try{ ~:;3uLs,8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9L%I<5i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G@!z$
SiteFileFetch fileFetch = new SiteFileFetch(bean); MgnM,95
fileFetch.start(); 2.}R
} sK$wN4k
catch(Exception e){e.printStackTrace ();} CR4rDh8za
?tf&pgo
78n}rT%k1
} 3HG;!D~m;
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dYFzye
public static void main(String[] args) @$Qof1j'%
{ mOll5O7VW
new TestMethod(); fbrp#G71y
} 1Wg-x0R
} :(3|HTz
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