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)); =]/<Kd}A.
} ={N1j<%fh
for(int i=0;i<nEndPos.length-1;i++) #Q*V9kvU/H
{ v=cQ`nou
nEndPos = nStartPos[i+1]; ,wBfGpVb
} ZrZDyXL
nEndPos[nEndPos.length-1] = nFileLength; WjM7s]ZRv
} j:/Z_v'
} R:R<Xt N`5
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&;L=f;
//启动子线程 .uxM&|0H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t4/ye>P &
for(int i=0;i<nStartPos.length;i++) _nxH;Za
{ uN>5Eh&=Pf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c-n/E. E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0\B{~1(^
nStartPos,nEndPos,i); yO!M$aOn/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w-LENdw
fileSplitterFetch.start(); $gD8[NAIx=
} ; D/6e6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L G5_\sY!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nb<oo:^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kw]?/s`
nEndPos = " + nFileLength); y)CvlI
// fileSplitterFetch[nPos.length-1].start(); u'>94Gm}
7Zdg314
U,;796h
//等待子线程结束 @|Yn~PwKs
//int count = 0; ctLNzJes%
//是否结束while循环 ms&1P
boolean breakWhile = false; q^Oj/ws
5Pn.c!
|('o g*$
while(!bStop) 2.b,8wT/
{ tH.L_< N
write_nPos(); ::$W .!Uv
Utility.sleep(500); .SER,],P
breakWhile = true; g3>>gu#0DC
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+qC[X~\
for(int i=0;i<nStartPos.length;i++) L~Peerby
{ `?3f76}h
if(!fileSplitterFetch.bDownOver) [xr^t1
{ /W BmR R
breakWhile = false; f pq|mY
break; K.Y`/<
} cGgfCF^`
} aK@ Y) Ju'
if(breakWhile) W.jXO"pN
break; % ym};7'&b
111A e*U
H)7v$A,5%
//count++; V@#oQi*
//if(count>4) TPk?MeVy%W
// siteStop(); %\T,=9tD\
} m x |V)
3c3;8h$k
`Y4Kw
System.err.println("文件下载结束！"); B#jnM~fJz
} oYZ 4F
catch(Exception e){e.printStackTrace ();} 3J &Ros
} v>B412l
nf 8V:y4
1Ng.Ukb
//获得文件长度 u*)/e9C
public long getFileSize() W wPzm?30
{ 2WFZ6
int nFileLength = -1; 3rH}/`d4
try{ L4m Vk
URL url = new URL(siteInfoBean.getSSiteURL()); X%IqZ{{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hDJG.,r
httpConnection.setRequestProperty("User-Agent","NetFox"); n*wQgC'vw
{&IB[Y6
e!*]y&W
int responseCode=httpConnection.getResponseCode(); eb\SpdM6
if(responseCode>=400) {jB>]7
{ %0C [v7\
processErrorCode(responseCode); ?`Yu~a{
return -2; //-2 represent access is error ]wU/yc)e
} -|#{V.G3'
m.m6.
1\m,8i+gU
String sHeader; c.IUqin
6-_g1vq
JVX)>2&$
for(int i=1;;i++) uNyN[U
{ d/Q#Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H@1'El\9
//Utility.log(in.readLine()); 2lpPN[~d
sHeader=httpConnection.getHeaderFieldKey(i); 5:IDl1f5
if(sHeader!=null) >^jBE''
{ N<rq}^qo
if(sHeader.equals("Content-Length")) uS`}
{ < bC'.m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); . fja;aG
break; .t1:;H b
} IAH"vHM
} Ur xiaE
else :6nD"5(
break; \s*UUODWK
} 8)1q,[:M
} ,yltt+e
catch(IOException e){e.printStackTrace ();} (`dz37@*
catch(Exception e){e.printStackTrace ();} UF!qp
Z|n|gxe
tVAo o-%
Utility.log(nFileLength); $M)i]ekm
Q&]|W Xv
;Yee0O!d4
return nFileLength; ]M*`Y[5"
} $\NqD:fgb
/(JG\Ut
&RZO\ZT
//保存下载信息（文件指针位置） `#ruZM066
private void write_nPos() xA Ez1
{ 4}m9,
try{ IrL%0&*hS
output = new DataOutputStream(new FileOutputStream(tmpFile)); b M1\z
output.writeInt(nStartPos.length); v=@y7P1
for(int i=0;i<nStartPos.length;i++) AaYH(2m-
{ k4V3.i!E
// output.writeLong(nPos); \:J=tAC
output.writeLong(fileSplitterFetch.nStartPos); rgVRF44X{
output.writeLong(fileSplitterFetch.nEndPos); OWewV@VXR
} 3Qe|'E,U
output.close(); @G2# Z
} Np+PUu>
catch(IOException e){e.printStackTrace ();} t\ oud{Cv
catch(Exception e){e.printStackTrace ();} 1jd{AqHl
} \+V"JIStUj
>O\+9T@
%N-aLw\
//读取保存的下载信息（文件指针位置） x\G%
private void read_nPos() I #1~CbR
{ I/njyV)H
try{ $~6MR_Yq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vT EqT
int nCount = input.readInt(); D:Q#%wJ
nStartPos = new long[nCount]; [bHm-X]
nEndPos = new long[nCount]; ,5$G0
for(int i=0;i<nStartPos.length;i++) $"vz>SuB
{ 1+Gq<]@G
nStartPos = input.readLong(); |`:cB
nEndPos = input.readLong(); qhY+<S9
} E'aOHSAg
input.close(); _+By=B.'
} *gwaW!=
catch(IOException e){e.printStackTrace ();} gw"cXny
catch(Exception e){e.printStackTrace ();} :o8`2Z*g
} eP]y\S*P
p*c(dkOe8
"BSY1?k{
private void processErrorCode(int nErrorCode) 8S#$'2sT
{ O z0-cM8t
System.err.println("Error Code : " + nErrorCode); z)C}}NH*!@
} "j_iq"J
DYf2V6'
iXm&\.%
//停止文件下载 v<v;ZR)
public void siteStop() mvjx &+q
{ /=;,lC
bStop = true; .rk5u4yK
for(int i=0;i<nStartPos.length;i++) 4nm.ea|
fileSplitterFetch.splitterStop(); ~JT2el2W7p
gg#9I(pX
hhPQ.{]>
} g*b`o87PI
} 8j>V?'Szk
//负责部分文件的抓取 z~h?"'
**FileSplitterFetch.java #tKks:eL
*/ ,Sgo_bC/|
package NetFox; 7#C$}1XJ1
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t,%m-dU
import java.io.*; TQO|C?
import java.net.*; 68?&`/t
m~Pk]~j
4|_xz;i
public class FileSplitterFetch extends Thread { lx2#C9L_
4C?{p%3c
Mk#r_:[BS
String sURL; //File URL &C MBTY#u
long nStartPos; //File Snippet Start Position }'Ap@4
long nEndPos; //File Snippet End Position :.AC%'S
int nThreadID; //Thread's ID z+.G>0M
boolean bDownOver = false; //Downing is over C2R"96M7q
boolean bStop = false; //Stop identical kKF=%J?X
FileAccessI fileAccessI = null; //File Access interface |[n\'Xy;{
SHYekX
:i>LESJq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m)66g]F+
{ @VP/kut
this.sURL = sURL; tiGH#~?
this.nStartPos = nStart; #8t=vb3
this.nEndPos = nEnd; a"P & 9c
nThreadID = id; 'E#L6,&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KLM6#6`
} BsXF'x<U*
H$ nzyooh
7|=SZ+g
public void run() HAE$Np|>a
{ EUt2S_2P
while(nStartPos < nEndPos && !bStop) S".|j$
{ DA=LR
JUw|nUnl?
+>1Yp">?
try{ ,+BFpN'
URL url = new URL(sURL); VB/75xK_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EIzTbW{p
httpConnection.setRequestProperty("User-Agent","NetFox"); &O+S[~
String sProperty = "bytes="+nStartPos+"-"; ){/n7*#Th%
httpConnection.setRequestProperty("RANGE",sProperty); dj084q7
Utility.log(sProperty); 6$PQ$
(~\HizSl
w@WtW8 p^
InputStream input = httpConnection.getInputStream(); |oeg'T
//logResponseHead(httpConnection); SgQmR#5
-GL.8"c[
nUq@`G
byte[] b = new byte[1024]; a$uDoi
int nRead; `Q+O#l?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) # .&t'"u
{ *@lVesC2
nStartPos += fileAccessI.write(b,0,nRead); lnl>!z
//if(nThreadID == 1) Q.4+"JoG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y"5FK
} p&(z'd
[Ketg
#?M[Q:
Utility.log("Thread " + nThreadID + " is over!"); N["M "s(N
bDownOver = true; QWm g#2'
//nPos = fileAccessI.write (b,0,nRead); 'u PI~l`g
} r^s$U,e#~
catch(Exception e){e.printStackTrace ();} |&S^L}V.C
} V:D?i#%,z
} Xa}y.qH
FzsW^u+
bneP>Bd
//打印回应的头信息 Ki:98a$
public void logResponseHead(HttpURLConnection con) F9_X^#%L
{ '&AeOn
for(int i=1;;i++) hNcEBSQ
{ vKbGG
String header=con.getHeaderFieldKey(i); s?sr0HZ
if(header!=null) 's8LrO(=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EffU-=?%!
Utility.log(header+" : "+con.getHeaderField(header)); jfR!M07|
else gU@.IOg
break; XC[AJ!q`
} NUY sQO)
} Ip,0C8T`Q
.GDY J9vi
\$8p8MP<&D
public void splitterStop() I} ]s(
{ "Bn]-o|r
bStop = true; n QOLR?%
} nza^<DlS
b\"2O4K,)
ra\2BS)X
} }PzYt~Z`@
SI l<\
{<^PYN>`
/* (@*#Pn|A
**FileAccess.java j98>Jr\
*//文件访问(定位，写) }~Y#N
package NetFox; aQfrDM<*XS
import java.io.*; CY8=prC
@|o^]-,
_i&awm/U
public class FileAccessI implements Serializable{ D)LqkfJ}z^
}"9jCxXL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =kWm9W<^
RandomAccessFile oSavedFile; !bD`2m[Q
long nPos; A?OaP
YR/rN,
-RnQ8Iuo
public FileAccessI() throws IOException KbF,jm5
{ E2{SKIUm
this("",0); faaFmEC
} GCPSe A~cx
A ptzBs/
gnSb)!i>z
public FileAccessI(String sName,long nPos) throws IOException du4Q^-repC
{ {oN7I'>
oSavedFile = new RandomAccessFile(sName,"rw"); sHulaX{
this.nPos = nPos; O>`DR0
oSavedFile.seek(nPos); snyg
} 2s@<k1EdPl
0dgp<
:X;'37o#q
public synchronized int write(byte[] b,int nStart,int nLen) vL7JzSU_
{ J Covk1
int n = -1; ,0=:06l
try{ .DSmy\FI5
oSavedFile.write(b,nStart,nLen); J@c)SK%2h
n = nLen; $fA%_T_P'P
} EBN'u&zX
catch(IOException e) @t6B\ ?4'T
{ 7Z/KXc[b
e.printStackTrace (); hqVFb.6[
} ;'r} D!8w/
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,9W|$2=F
return n; .W<yiB}^
} -&* 4~
C&m[/PJ~l
257pO9]
} h$EH|9HAb
}Q?,O
\ueo^p]_?
/* ch}t++`l]
**SiteInfoBean.java ['~B&
*/ B#_<?
package NetFox; 2R2ws.}
((}T^
3U0>Y%m|,
public class SiteInfoBean { i5sNCt
~e5hfZv|w
1>1&NQ#}
private String sSiteURL; //Site's URL Uv~r]P)
private String sFilePath; //Saved File's Path 9"3 7va
private String sFileName; //Saved File's Name E {$Jk]c
private int nSplitter; //Count of Splited Downloading File =G%k|
T\VKNEBo
WKib$(%f6
public SiteInfoBean() F/FUKXxx
{//nSplitter的缺省值为5 v"VpE`z1#
//default value of nSplitter is 5 ;N4A9/)
this("","","",5); [%M=nJ{8
} X\:;A{
59;p|
G=R`O1-3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $[L~X M
{ ,iKL 68
sSiteURL= sURL; !e5!8z
sFilePath = sPath; xx`xDD
sFileName = sName; #1-,s.)
this.nSplitter = nSpiltter; {k4)f ad\
?6;9r[ p
\':'8:E
} q#RUL!WF7U
m5c?A+@fZ
"]1 !<M6\i
public String getSSiteURL() zPzy0lx
{ TYv'#{
return sSiteURL; F xek#
} or~2r8
|]--sUx:
>|{n";n&
public void setSSiteURL(String value) ,E8:!r)6
{ UoAHy%Y<%
sSiteURL = value; 0,b.;r
} d}@b 3
b#~K>
Z^tTR]u\$
public String getSFilePath() O52B
{ J,iS<lV_
return sFilePath; B*0TM+
} @c;XwU]2t
>:o$h2
(G1KMy
public void setSFilePath(String value) C{{RU7iqc&
{ F,dPmR
sFilePath = value; `$PdI4~J
} .rPg
Nxm^jPM0
W;Y"J_
public String getSFileName() ke2zxX2f
{ /penB[1i
return sFileName; 6Qc *:(GE
} qjr:(x/
9%#u,I
Z;ze{Vb
public void setSFileName(String value) plNoI1st
{ %I^schE*
sFileName = value; 7MbV|gM}
} L`2(u!i J
$)YalZ
r+Pfq[z&
public int getNSplitter() fw&cv9X(IU
{ yac4\%ze
return nSplitter; +X%pUe
} po! [Nd&"
W{$J)iQ
xcQD]"
public void setNSplitter(int nCount) R@df~
{ <)$e*HrI
nSplitter = nCount; +B '<0
} Vg^yjP{sv
} Leu6kPk
7VIfRN{5n
j'uzjs[
/* r1&eA%eh
**Utility.java 2!)|B ;y
*/ IKrojK8-?
package NetFox; 2RU/oqmR
gJH^f3
F05]6NVv
public class Utility { 7](aPm8
v8"Zru
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public Utility() /g>]J70
{ 3dx.%~c
I]z4}#+cX
% !>@m6JK
} >~l^E!<i-u
en"\2+{Cg
//线程睡眠 jL{k!V`s
public static void sleep(int nSecond) s-4qK(ml-
{ vX?C9Fr2
try{ c;,-I
Thread.sleep(nSecond); 6`@6k2]
} 1j]vJ4R_\
catch(Exception e) 12V-EG i
{ g;7W%v5wqk
e.printStackTrace (); ?jU 3%"
} ,:{+-v(
} R_=fH\c;
(+nnX7V?I
//日志 Eb8~i_B-
public static void log(String sMsg) kZ0z]Y
{ BxiR0snf0q
System.err.println(sMsg); g^{a;=
} .IsOU
Rw<O%i5/d
qN^]`M[ BY
public static void log(int sMsg) 09=w
{ `NyO|9/4
System.err.println(sMsg); DB0?H+8t
} ~i]4~bkH2
} P\h1%a/D
`[h&Q0Du6
I0N~>SpZ5
/* xxG>Leml
**TestMethod.java lSy_cItF
*/ )Wk&c8|y
package NetFox; 9RC:-d;;_
D|2lBU
S3Fj /2Q8
public class TestMethod { RLO<5L
/Ri-iC >
O' Mma5
public TestMethod() 4O4}C#6(4
{ ///xx/weblogic60b2_win.exe a_zf*;
try{ H|3CZ=U?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qykI[4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mj ,Oy
SiteFileFetch fileFetch = new SiteFileFetch(bean); @>F`;'_*z
fileFetch.start(); P!!:p2fo
} !,~C
catch(Exception e){e.printStackTrace ();} N.vkM`Z
(\4YBaGd
aW#^@||B
} UoJMOw[
Q) iN_|
AQPzId*z
public static void main(String[] args) +WvW#wpH
{ ||;a#FZ^
new TestMethod(); w!RJ8
} lgC^32y
} 5 HN,y
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