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)); ",,qFM!
} B#/~U`t*
for(int i=0;i<nEndPos.length-1;i++) &hM,b!R|
{ -QHzf&D?
nEndPos = nStartPos[i+1]; B'#gs'fl
} d'eM(4R@
nEndPos[nEndPos.length-1] = nFileLength; ,:Y=,[n
} =S?-=jPtg
} d ;Gm{g#
!z&seG]@
\2VZkVO9
//启动子线程 ?2bE=|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]a@v)aa-
for(int i=0;i<nStartPos.length;i++) ]MH \3g;
{ cB{;Nh6"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o@V/37!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B2+_F"<;
nStartPos,nEndPos,i); q~A|R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uS+b* :
fileSplitterFetch.start(); fqp7a1qQl
} FK,r<+h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0BU:(o&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h"%,eW|^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YUE1 '}
nEndPos = " + nFileLength); hE3jb.s(>
// fileSplitterFetch[nPos.length-1].start(); qcoZ2VJ hh
Sv]"Y/N
Z(clw
//等待子线程结束 N`mC_)
//int count = 0; =P+wp{?AN|
//是否结束while循环 cH8H)55F
boolean breakWhile = false; f\%X7.
=GS_ G;Dz
74!JPOpQH
while(!bStop) uX5B>32
{ K {N;k-
write_nPos(); hQRc,d6x5
Utility.sleep(500); r?{LQWP>e
breakWhile = true; ri.|EmH2:D
Y&:\s8C
}jy7,+
for(int i=0;i<nStartPos.length;i++) Iw-6Z+ 94
{ %4g4 C#
if(!fileSplitterFetch.bDownOver) 4xC6#:8
{ !P3tTL!*L
breakWhile = false; kJ:5msKwC
break; ~#xs `@{s
} ^K@GK
} R5YtCw]i=
if(breakWhile) Q0cf]
break; xuC6EK+
G`<1>%"F
\>CBam8d
//count++; wB0WR
//if(count>4) ^{,}, i
// siteStop(); W2V@\
} ,DsT:8
y"n~ET}e7
$7ME a"a
System.err.println("文件下载结束！"); %-zH]"Q$
} ZXRN?b
catch(Exception e){e.printStackTrace ();} $TUC?e9"h
} mi3q1npb7[
8XXTN@&,
-^%"w
//获得文件长度 RB 0j!H:
public long getFileSize() O&1p2!Bk4
{ "e?#c<p7
int nFileLength = -1; lIT2 AFX+
try{ p~y 4q4
URL url = new URL(siteInfoBean.getSSiteURL()); /IR5[67
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aQ3vG08L>
httpConnection.setRequestProperty("User-Agent","NetFox"); +Gs;3jC^
m^&mCo,
*^m.V=
int responseCode=httpConnection.getResponseCode(); ?9M+fi
if(responseCode>=400) B,qZwc|
{ 2QD B'xs3
processErrorCode(responseCode); T</gWW
return -2; //-2 represent access is error cnO4NUDv
} MjosA R
:)S4MoG
z^a?t<+
String sHeader; {nWtNyJpS
D%}o26K.C
DWO:
for(int i=1;;i++) 0iq$bT|
{ *8HxJ+[,[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 57%cN-v*
//Utility.log(in.readLine()); ",oUVl
sHeader=httpConnection.getHeaderFieldKey(i); =njj.<BO
if(sHeader!=null) x}24?mP
{ zTzG&B-
if(sHeader.equals("Content-Length")) Q9 ",
{ aj~@r3E;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {?_)m/\
break; 3W00,f^9
} KV(W|~+rM
} Vc<n6
else <GlV!y
break; 745PCC'FK
} lY,1 w
} 0|k[Wha#
catch(IOException e){e.printStackTrace ();} /9gMcn9EB
catch(Exception e){e.printStackTrace ();} =hb87g.
atnbM:t
%zVv3p:
Utility.log(nFileLength); y9mZQq
UeTp,
SQvB)NOw
return nFileLength; EnAw8Gm*
} qWK7K%-$E
TUCpmj
O\{_)L
//保存下载信息（文件指针位置） zL}DLfy>R
private void write_nPos() ZPFTNwf
{ V,,iKr@TG
try{ "lAS <dq
output = new DataOutputStream(new FileOutputStream(tmpFile)); FV,SA3
output.writeInt(nStartPos.length); LB0=V0|
for(int i=0;i<nStartPos.length;i++) 2)]*re)
{ ?NeB_<dLa`
// output.writeLong(nPos); {[#
output.writeLong(fileSplitterFetch.nStartPos); !7|9r$
output.writeLong(fileSplitterFetch.nEndPos); "6h.6_bTw
} #J9XcD{1
output.close(); RGOwm~a
} uQ)]g
catch(IOException e){e.printStackTrace ();} yQ2[[[@k@
catch(Exception e){e.printStackTrace ();} SpQ6A]M gm
} bsDUFXH]
J?DyTs3Z
D]y.!D{l2
//读取保存的下载信息（文件指针位置） 9a,CiH%@
private void read_nPos() [X\2U4
{ 6ng9 o6
try{ X:bgY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /d;l:
int nCount = input.readInt(); =-Tetp
nStartPos = new long[nCount]; n\,W:G9AR7
nEndPos = new long[nCount]; X^)5O>>|t
for(int i=0;i<nStartPos.length;i++) Ue%5 :Sdr
{ ]>j_ Y,
nStartPos = input.readLong(); -': tpJk
nEndPos = input.readLong(); BGOI
} %oQj^r!Xd
input.close(); KO7cZME
} s^< oU
catch(IOException e){e.printStackTrace ();} P]^] T}5
catch(Exception e){e.printStackTrace ();} 4(]('[M
} HX^ P9jXT
^4i3#}
WR%iUO40
private void processErrorCode(int nErrorCode) OC.@C}u
{ M1\/ueOe
System.err.println("Error Code : " + nErrorCode); jeNEC&J
} 0cVXUTJ|W
=$J2
MR: {Ps&,
//停止文件下载 C5?M/xj
public void siteStop() F[Up
{ m5*RB1
bStop = true; sIe(;%[`
for(int i=0;i<nStartPos.length;i++) $Vh82Id^
fileSplitterFetch.splitterStop(); ':@qE\(
UNae&Zir
XFYl[?`G
} X8TZePh
} [0emOS
//负责部分文件的抓取 6cvm\opH
**FileSplitterFetch.java 4kEFbzwx
*/ .Dz /MSl
package NetFox; KYaf7qy]
c{q`uI;O
7v_e"[s~
import java.io.*; ~heF0C_
import java.net.*; bzS [X
agzG
YXEZ&$e'
public class FileSplitterFetch extends Thread { ycN_<
I._=q
a;sZNUSn
String sURL; //File URL ?u|g2!{_
long nStartPos; //File Snippet Start Position >F v8 -
long nEndPos; //File Snippet End Position AseY.0
int nThreadID; //Thread's ID {cFei3'q
boolean bDownOver = false; //Downing is over dLq!t@?iu>
boolean bStop = false; //Stop identical -1:asM7
FileAccessI fileAccessI = null; //File Access interface "lt[)3*
2I
195(Kr<5$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~Q0}>m,S
{ Yv)/DsSyL
this.sURL = sURL; ~czt=
this.nStartPos = nStart; DDEn63{
this.nEndPos = nEnd; Syb:i(Y
nThreadID = id; AKVmUS;70
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SF7Kb`>Y
} Q\Eq(2p
o/xE O=AW
[F$3mzx
public void run() -JK+{<
{ rm7UFMCR6i
while(nStartPos < nEndPos && !bStop) C/JFg-r
{ ZJqmD
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+q;^8d>
try{ G(- `FH
URL url = new URL(sURL); wFD.3!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x8^Dhpr6
httpConnection.setRequestProperty("User-Agent","NetFox"); 9bB~r[k
String sProperty = "bytes="+nStartPos+"-"; a)e2WgVB/E
httpConnection.setRequestProperty("RANGE",sProperty); Z,z^[Jz
Utility.log(sProperty); ]KmYPrCl0
B4?P"|
Tr8+E;;
InputStream input = httpConnection.getInputStream(); F=#Wfl-o
//logResponseHead(httpConnection); |[ge,MO:
c=5$bo]LI
8{RiaF8
byte[] b = new byte[1024]; 9"rATgN1
int nRead; px*MOHq K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z7Kc`9.0|
{ 5R4 dN=L*1
nStartPos += fileAccessI.write(b,0,nRead); Gs%kqD{=
//if(nThreadID == 1) iR9iI!+;N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _>*"6
} KLk37IY2\
eNNK;xXe#
B?]^}r
Utility.log("Thread " + nThreadID + " is over!"); `?)i/jko"
bDownOver = true; ??F{Gli"C`
//nPos = fileAccessI.write (b,0,nRead); #KIHq2:.4
} yC -4wn*
catch(Exception e){e.printStackTrace ();} C-Mop,w
} xc!"?&\*
} \<5xf<{
bvoR?D\-"
xn-n{U"
//打印回应的头信息 8ViDh
public void logResponseHead(HttpURLConnection con) 6l4l74
{ 0wx`y$~R
for(int i=1;;i++) 4x:fOhtP
{ g {00i
String header=con.getHeaderFieldKey(i); ;y"DEFs,u
if(header!=null) ykZ)`E]P`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vm(% u!_P
Utility.log(header+" : "+con.getHeaderField(header)); Co'dZd(
else A9"ho}<
break; -kJ`gdS
} 8?PNyO-Wt5
} }&=C*5JN
fE(rDQI
,QK>e;:Be
public void splitterStop() 4 1Ru@
{ N-^\e)ln
bStop = true; qZ4DO*%b3
} H)5]K9D
D~-Ri`k.
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} 'p<(6*,"
pvX\kX3}
[u<1DR
/* ?xy~N?N
**FileAccess.java Q@2Smtu~c
*//文件访问(定位，写) x{=ty*E
package NetFox; us/x.qPy2
import java.io.*; n04Zji(F@
7y:J@fh<
+Ta7b)
public class FileAccessI implements Serializable{ 6%)dsTAB
!4|7U\;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HH>]"mv
RandomAccessFile oSavedFile; /@0wbA
long nPos; .6r&<*
P5[.2y_qM
>]Y`-*vw&
public FileAccessI() throws IOException 5RqkAC
{ rt f}4.
this("",0); 291v R]
} <jxTI%'f59
Up8#Nz T
=l {>-`:
public FileAccessI(String sName,long nPos) throws IOException 5{{u #W%=
{ %KqXtc`O
oSavedFile = new RandomAccessFile(sName,"rw"); `*WR[c
this.nPos = nPos; GR/ p%Y(
oSavedFile.seek(nPos); 90Q}9T\
} t; "o,T
'l2`05
9Czc$fSSt
public synchronized int write(byte[] b,int nStart,int nLen) sI#K01;"
{ cBU>/ zIp
int n = -1; F$d`Umqs;P
try{ /']Gnt G.
oSavedFile.write(b,nStart,nLen); x6m21DWw
n = nLen; kYx|`-PA<r
} 0nBAO
catch(IOException e) zg[ksny
{ d]CRvzW
e.printStackTrace (); J3C"W794}
} -V(5U!^B
3HWI;
E:#VS~
return n; 7,Nd[ oL*7
} k{uc%6s
V0"UFy?i
JWC{"6
} !YCYmxw#
+[:}<^p?cG
ZVViu4]?y
/* >wZ!1Jq
**SiteInfoBean.java CJ?Lv2Td
*/ \=1k29O
package NetFox; =Bl#CE)X
H~fZA)W 4Y
$kg!XT{V
public class SiteInfoBean { #k*e>d$
fZ$8PMZv
F8.Fp[_tM
private String sSiteURL; //Site's URL >AJtoJ=j
private String sFilePath; //Saved File's Path jrG@ +" }
private String sFileName; //Saved File's Name IX$ $pdQ
private int nSplitter; //Count of Splited Downloading File 't2"CPZ
klv ]+F&[
//g~1(
public SiteInfoBean() Vc}m_T]O
{//nSplitter的缺省值为5 Za5*HCo
//default value of nSplitter is 5 c)+IX;q-C
this("","","",5); 0fwo8NgX
} T-uI CMEf
5_#wOz0u$
Y ~xcJH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c=h{^![$
{ l\JoWL
sSiteURL= sURL; )FYz*:f>&
sFilePath = sPath; NbSkauF~b
sFileName = sName; X^7bOFWE
this.nSplitter = nSpiltter; =T!iM2
U8;k6WT|
C([TolZ
} >^{}Hjt
|s+y]3-_
C&D!TR!K
public String getSSiteURL() RKx" }<#+
{ YOd0dKe
return sSiteURL; 7jvf:#\LtL
} }]'Z~5T
Quqts(Q)+
C5$1K'X@
public void setSSiteURL(String value) \GEFhM4)
{ "o+< \B~
sSiteURL = value; I5 "Z
} ?l &S:` L
p$0G EYwM
(0bvd
public String getSFilePath() amK"Z<V F
{ $<OX\f%
return sFilePath; GFB(c
} :D""c*
i]JD::P_H
c=0S]_
public void setSFilePath(String value) mR)Xq=
{ VE`5bD+%e
sFilePath = value; Ys|tGU
} .i) H1sD
bx#GOK-
7jQOwzj
public String getSFileName() *VG#SK
{ 40w,:$
return sFileName; N7v7b<6
} Tu"bbc
&!SdO<agZ
p8aGM-+40W
public void setSFileName(String value) <%Zg;]2H`
{ _Ryt|# y
sFileName = value; R?Vs8?
} G~5EAeG
{N42z0c
Z]V^s8>
public int getNSplitter() B4Ko,=pg
{ ["TUSf]
return nSplitter; gdPv,p19L
} W$>srdG0$
5|z>_f.^pS
&@p_g8r#
public void setNSplitter(int nCount) [H<![Z1*r
{ OGpy\0%
nSplitter = nCount; ">_<L.,I
} % P .(L
} K%h9'}pq>1
SaceIV%(
V3r1|{Z(
/* <&^P1x<x
**Utility.java _4Z|O]
*/ jM]B\cvN
package NetFox; h8B:}_Cu
_IYd^c
C-O~Oil
public class Utility { <#/r.}.x
(&t741DN|
#;~`+[y?\
public Utility() xMsSZ{j%5
{ .$&mWytw=
=;Ap+}
gT8Q:8f:
} z=%&?V
:59fb"^$
//线程睡眠 @-ps[b`z
public static void sleep(int nSecond) Hj(ay48
{ Lu?MRF f
try{ }x!=F<Q!r
Thread.sleep(nSecond); ]z3!hgTj
} >n3w'b
catch(Exception e) uy'm2
{ G8AT] =
e.printStackTrace (); iXLODuI
} l Oxz&m
} NN>E1d=
"}ibH{$lM
//日志 B}S!l>.z
public static void log(String sMsg) K!~j}z*
{ }\ kLh(
System.err.println(sMsg); r:N =?X`N
} LL% Aw)Q`
1'Sr0 oEd3
?|,dHqh{nM
public static void log(int sMsg) n1!hfu7@s
{ NSs"I]
System.err.println(sMsg); D/U=zDpiB
} q~:H>;:G-
} zP554Gr?
im,H|u_f4
n$Nb,/o
/* 9d kuvk}:
**TestMethod.java <e&88{jJ
*/ ''D\E6c\
package NetFox; vtx3a^
AUk-[i
~V34j:
public class TestMethod { py|ORVN(Z
z3Id8G&>
=#=<%HPT
public TestMethod() @kh:o\
{ ///xx/weblogic60b2_win.exe k]>1@t
try{ WzinEo{f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oz8z%*9(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #Sg< 9xsW
SiteFileFetch fileFetch = new SiteFileFetch(bean); [pY1\$,
fileFetch.start(); dMd2a4
} FT'2J
catch(Exception e){e.printStackTrace ();} Y9<N#h#
-ElK=q
uy'I#^Bt
} Kx4_`;>
YzA6*2
3[{RH*nHD
public static void main(String[] args) *C~$<VYI
{ mv,p*0
new TestMethod(); n3z]&J5fr
} Z-U-n/6I
} VsU*yG a
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