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)); /yS/*ET8
} 2rJeON
for(int i=0;i<nEndPos.length-1;i++) bjYaJtn
{ Vm <9/UG<
nEndPos = nStartPos[i+1]; Jdp@3mP
} k=):>}
nEndPos[nEndPos.length-1] = nFileLength; yCG<qQz
} @%sr#YqY
} 1I -LGe[Q
+F3`?6UXz
VPqMbr"L[
//启动子线程 zS+_6s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R x.]m0
for(int i=0;i<nStartPos.length;i++) W:z!fh-
{ #8[iqvE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7f\@3r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A T'P=)F@
nStartPos,nEndPos,i); #cD20t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *.ZU" 5e
fileSplitterFetch.start(); aR~Od Ys
} I~.d/!>Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <OC|z3na_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .&Ok53]b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xRU ~hQ
nEndPos = " + nFileLength); duk:: |{F
// fileSplitterFetch[nPos.length-1].start(); KGoHn6jM
l`A4)8Y@
,t=12R]>
//等待子线程结束 ,dO$R.h
//int count = 0; 81<0B@E
//是否结束while循环 Z2x%
boolean breakWhile = false; :u$+lq
Qo;#}%}^^
)Mj $/
while(!bStop) eX@7f!uz
{ J\V.J/
write_nPos(); GxR, 3
Utility.sleep(500); {BlKVsQ
breakWhile = true; U\\nSU
,@'M'S
+\O[)\
for(int i=0;i<nStartPos.length;i++) Udh!%QP%[w
{ 6Y[|xu:N8Y
if(!fileSplitterFetch.bDownOver) WDdp(<
{ k;9"L90
breakWhile = false; ']]&<B}mz
break; GXE6=BO
} @\UoZv(
} qm&Z_6Pw
if(breakWhile) 4/Bn9F
break; Ft)Z'&L
_%$(D"^j
ef;Ta|#
//count++; ttK`*Ng
//if(count>4) BLvI[b|3gn
// siteStop(); KZxA\,Y'5
} _,i+gI[
5@{+V!o,
Mn=5yU
System.err.println("文件下载结束！"); 8{GRrwQ>
} 23;e/Qr
catch(Exception e){e.printStackTrace ();} .V\M/q\Tv
} !dW77kLTg
qJ|n73yn
r4D6I,
//获得文件长度 *!gj$GK@%
public long getFileSize() QFfKEMN
{ X}5aE4K/
int nFileLength = -1; ;I+"MY7D
try{ #!FLX*,
URL url = new URL(siteInfoBean.getSSiteURL()); Q#i^<WUpg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,OQ!lI_`R
httpConnection.setRequestProperty("User-Agent","NetFox"); XT|!XC!|
weOzs]uc
&z\]A,=Tc
int responseCode=httpConnection.getResponseCode(); WSY&\8
if(responseCode>=400) -|DSfI#j
{ @MV%&y*z.
processErrorCode(responseCode); PZdYkbj
return -2; //-2 represent access is error epH48)2
} .2b) rKo~
^!*?vHx:
Z-{!Z;T)z
String sHeader; (&6C,O~n^.
/I'n]
?]=fC{Rh
for(int i=1;;i++) 9o7d3ir)
{ #f'(8JjY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y"uFlHN&i
//Utility.log(in.readLine()); Jb~-)n2
sHeader=httpConnection.getHeaderFieldKey(i); E00zf3Jgv'
if(sHeader!=null) xmDX1sL**
{ Ohm>^N;
if(sHeader.equals("Content-Length")) G@)I
{ !_`T8pJ`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); toipEp<ci
break; !j(KbAhWZ
} MGO.dRy_
} LC/w".oq?
else fxDY:l
break; hG,gY;&[6
} 2.2Z'$W
} 6[9E^{(z
catch(IOException e){e.printStackTrace ();} 4M8AYh2)
catch(Exception e){e.printStackTrace ();} vII8>x%*
RZfC?
1>*]jj}
Utility.log(nFileLength); >5Zpx8W
~^.&nph
6,xoxNoPP3
return nFileLength; NEO~|B*oDU
} `~(C\+gUp
x~GV#c
s9A'{F
//保存下载信息（文件指针位置） tji,by#E/%
private void write_nPos() !dLz ?0
{ LIH>IpamN
try{ J1<fE(X
output = new DataOutputStream(new FileOutputStream(tmpFile)); JXeqVKF
output.writeInt(nStartPos.length); 1V`]sfRK
for(int i=0;i<nStartPos.length;i++) -aNTFt~|[
{ skcMGEB
// output.writeLong(nPos); x 0
output.writeLong(fileSplitterFetch.nStartPos); &1Fcwj
output.writeLong(fileSplitterFetch.nEndPos); EGwY|+3
} Snt=Hil`
output.close(); H/V%DO
} |?Q(4(D`*
catch(IOException e){e.printStackTrace ();} &Jj> jCg
catch(Exception e){e.printStackTrace ();} E|9LUPcb
} YeJ95\jf
g]xZ^M+
~,e!t.339
//读取保存的下载信息（文件指针位置） t%z7#}9$
private void read_nPos() >*}qGk
{ 3i(k6)H$4
try{ SEchF"KJQF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BHmA*3?
int nCount = input.readInt(); ~rCnST
nStartPos = new long[nCount]; n@L!{zY
nEndPos = new long[nCount]; <J-OwO a-1
for(int i=0;i<nStartPos.length;i++) 8"LaP3U
{ )O- x1U
nStartPos = input.readLong(); l``1^&K
nEndPos = input.readLong(); @\l> <R9V
} F.8{ H9`
input.close(); w=e,gNO
} 6sy%KO*A
catch(IOException e){e.printStackTrace ();} F'CUkVC0~P
catch(Exception e){e.printStackTrace ();} +lha^){
} GIVs)~/Eq
qd|*vE
CES FkAj~
private void processErrorCode(int nErrorCode) UxicqkX
{ 24N,Bo 3
System.err.println("Error Code : " + nErrorCode); #>'1oC{
} H[N&Wiq/|
pjj 5
G^mk<pH
//停止文件下载 'v|2}T*
public void siteStop() ^RWt
{ P'9aZd
bStop = true; g&0GO:F`
for(int i=0;i<nStartPos.length;i++) 4_.k Q"'DH
fileSplitterFetch.splitterStop(); K[sM)_I
?XOeMI
9jPb-I-
} 2Bjp{)*
} {t/!a0\HS
//负责部分文件的抓取 <M'IRf/D
**FileSplitterFetch.java 9_>4~!x`
*/ iKabo,~
package NetFox; Y(SI`Xo[
b"FsT
yL Q&<\
import java.io.*; r3j8[&B"
import java.net.*; Zc4hjg
Ic=V:
$g$`fR)
public class FileSplitterFetch extends Thread { )ql?}
#6H<JB
pn $50c
String sURL; //File URL J#x91Jh
long nStartPos; //File Snippet Start Position ONjc},_
long nEndPos; //File Snippet End Position d}o1 j
int nThreadID; //Thread's ID >Au<y,Tw
boolean bDownOver = false; //Downing is over 78QFaN$
boolean bStop = false; //Stop identical ?3Jh{F_+
FileAccessI fileAccessI = null; //File Access interface 2mlE;.}8
|%V.Lae
I(<G;ft<}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u3. PHZ
{ >rFvT>@NU
this.sURL = sURL; %9D@W*Z
this.nStartPos = nStart; /3TorB~Y
this.nEndPos = nEnd; BkZ%0rw%
nThreadID = id; KncoIw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'j)eqoj
} `2fuV]FW
tJu<#hX
sMS`-,37u
public void run() "G,*Z0V5
{ |wb7`6g
while(nStartPos < nEndPos && !bStop) |fI%L9
{ 7.Mh$?;i9
?0(B;[xEJ
O^xt
try{ *tO<wp&
URL url = new URL(sURL); B)Q'a3d#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (;j7{(
httpConnection.setRequestProperty("User-Agent","NetFox"); @iP6N
String sProperty = "bytes="+nStartPos+"-"; hrL<jcv|
httpConnection.setRequestProperty("RANGE",sProperty); ww,c)$
Utility.log(sProperty); 4By-+C*
5->PDp
OX`n`+^D
InputStream input = httpConnection.getInputStream(); 6+u'Tcb
//logResponseHead(httpConnection); d$TW](Bby
$F-XXBp
PW`Tuj
byte[] b = new byte[1024]; H\k5B_3OU
int nRead; >eTlew<5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CbHNb~
{ :9YQX(l8
nStartPos += fileAccessI.write(b,0,nRead); -0X> y
//if(nThreadID == 1) @iRVY|t/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1}uDgz^
} c'B"Onu@m*
"n6Y^
J7_H.RPa
Utility.log("Thread " + nThreadID + " is over!"); !:t9{z{Ixg
bDownOver = true; |i`@!NrFL
//nPos = fileAccessI.write (b,0,nRead); ;gMh]$|"
} "P{&UwMmh
catch(Exception e){e.printStackTrace ();} Xdq, =;
} *YtNt5u
} B~NC
~/U0S.C
CN=&Je%I
//打印回应的头信息 ~tLR
public void logResponseHead(HttpURLConnection con) _'7/99]4g}
{ *02( J
for(int i=1;;i++) W*<]`U_.
{ <C$<(Dw5
String header=con.getHeaderFieldKey(i); jyGVbno`
if(header!=null) 2 QmUg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]p!J]YV ]0
Utility.log(header+" : "+con.getHeaderField(header)); i4I0oRp
else v/czW\z
break; fI1;&{f
} Du>HF;Fv
} 3I5WDuq
OVyy}1Hx
88>Uu!M=f
public void splitterStop() Z~(XyaN
{ JLu0;XVK
bStop = true; Ln_l>X6j51
} j1F+,
%-l:_A
PBL^xlg
} OD]J@m
"AouiZkh
XX-T",
/* qYiAwK$
**FileAccess.java r(i)9RI+(
*//文件访问(定位，写) 4c=kT@=jX
package NetFox; (@E#O$'
import java.io.*; {{3H\ rR
S7a6ntei
W6O.E
public class FileAccessI implements Serializable{ 1[l>D1F?
n6G&^Oj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 : xZC7"
RandomAccessFile oSavedFile; F?} *ovy
long nPos; udGGDH
%h"< IA S.
A{2$hKqHi
public FileAccessI() throws IOException txo?k/w
{ s7o*|Xv
this("",0); #`4^zU)
} t4@g;U?o
6\Vu#r
MNqyEc""
public FileAccessI(String sName,long nPos) throws IOException g u =fq\`
{ \hW73a!
oSavedFile = new RandomAccessFile(sName,"rw"); ]zU<=b@
this.nPos = nPos; Sqf.#}u<=
oSavedFile.seek(nPos); KN:dm!A
} :EwA$`/
%_MR.J+m2
yl<$yd0Zdu
public synchronized int write(byte[] b,int nStart,int nLen) }AW)R&m
{ }pnFJ
int n = -1; xqWrW)
try{ ,?<h] !aQ
oSavedFile.write(b,nStart,nLen); 1vs>2` DLa
n = nLen; WlQ=CRY
} Kw0V4UF
catch(IOException e) 0~b6wuFl
{ !7`=rT&
e.printStackTrace (); pE/3-0;}N
} d4>-a^)V
8ex:OTzn|
rg^\BUa-W,
return n; 4VJzs$
} 2Lekckgv
"!Oh#Vf
DUKmwKM"k
} yr9A0F0
qj"syO
[l%fL9
/* /B@%pq
**SiteInfoBean.java +wW
*/ _@pf1d$
package NetFox; kqigFcz!Y
&@utAuI
11<@++,i
public class SiteInfoBean { L+rySP
P9i9<pR
vDeG20.?Z
private String sSiteURL; //Site's URL sQ:VrXwP
private String sFilePath; //Saved File's Path 9=~H6(m>
private String sFileName; //Saved File's Name N"1x]1'
private int nSplitter; //Count of Splited Downloading File RrU~"P1C
k\&IFSp
<<On*#80w
public SiteInfoBean() 0S:!Gv+
{//nSplitter的缺省值为5 qVD!/;l
//default value of nSplitter is 5 @VC9gdO/
this("","","",5); Qv0>Pf
} @52=3
7R<u=U
RQS:h]?:l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m)|.:sj
{ '"]>`=R
sSiteURL= sURL; f+TBs_
sFilePath = sPath; yCkW2p]s,K
sFileName = sName; *o e0=
this.nSplitter = nSpiltter; &Wv`AoV
fFZ`rPb
F `pyhc>1;
} XJlDiBs9=Q
7{+Io
\LoSUl i
public String getSSiteURL() o(X90X
{ Hu9-<upc&
return sSiteURL; Z!RRe]"y
} +ersP@G
IJ_'w[k
*4hOCQ[
public void setSSiteURL(String value) 1f@U:<:
{ xH`j7qK.
sSiteURL = value; ]IHD:!Z-=
} WrHgF*[
K+7yUF8XP
'x45E.wYw
public String getSFilePath() {b-0_
{ Z\*5:a]
return sFilePath; LN~N Fjs
} +6#%P
Mdltzy=)L
w*6!?=jP
public void setSFilePath(String value) ,p*ntj{
{ rtYb"-&
sFilePath = value; ~E3SC@KL
} C:s^s
x<{;1F,k3
&w;^m/zP3
public String getSFileName() >G4HZE
{ 5}X<(q(
return sFileName; anz9lGG#
} VM<oUKh_3
V 4\^TO`q=
1%/ NL?8#
public void setSFileName(String value) i^yH?bH @~
{ 2{sD*8&`
sFileName = value; m|nL!Wc
} J/]o WC`u
`u p-m=zA
9N*S-Po=
public int getNSplitter() >p]WCb'PH
{ 5Aa31"43n
return nSplitter; `uNvFlP
} L.IoGUxD
I!F}`d
,Ou1!`6?t
public void setNSplitter(int nCount) %2Xus9;k#
{ f74%YY
nSplitter = nCount; ~C/Yv&58
} qL%.5OCn(
} c#\ah}]Vo
oRT
QLF,/"
/* 8u:v:>D.'
**Utility.java n!kk~65|
*/ PuCwdTan_
package NetFox; Y-Ziyy
)tN?: l
LY\ddI*s
public class Utility { KlVi4.]
>YJ8u{Z{o
]/ZA/:Oa+
public Utility() e9z$+h
{ G!!-+n<
#RR:3ZPZC
HsjELbH
} e?^\r)1
3r~>~ueZ
//线程睡眠 PmPyb>HK=P
public static void sleep(int nSecond) HO%E-5b9
{ 2d5}`>
try{ #sz]PZ\
Thread.sleep(nSecond); ?$30NK3G
} bk\dy7
catch(Exception e) ;xW8Z<\-
{ #Dj"W8'zh
e.printStackTrace (); aW`:)y&f
} zmy4tsmX
} AkYupP2]v
G8^0^@o
//日志 ":UWowJO
public static void log(String sMsg) 2X qTyf<
{ pY{; Yn&t
System.err.println(sMsg); 'L>&ZgLy
} rQu
+Fc ET
~ V@xu{
public static void log(int sMsg) N`,7FI}
{ HZQDe&
System.err.println(sMsg); Hk<X
} d'N(w7-Y
} hw&ke$Fg#
XPHQAo[(s
Cp .1/
/* S+.21,
**TestMethod.java ri/t(m^{W
*/ w8AJ#9W
package NetFox; #d}0}7ue
^?$D.^g
& cM u/}
public class TestMethod { c8^+^.=pX
:3111}>c
-kG3k> by_
public TestMethod() (w5u*hx
{ ///xx/weblogic60b2_win.exe |Hx%f
try{ =8$|_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m.1LxM$8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5xh!f%6
SiteFileFetch fileFetch = new SiteFileFetch(bean); @Ufa-h5"(
fileFetch.start(); =3h+=l[
} !7A"vTs
catch(Exception e){e.printStackTrace ();} :.C+?$iuX
,|e}Y [
??%)|nj.
} U>/<6Wd
IY];Ss&i
bin6i2b
public static void main(String[] args) ]*bAF^8i
{ XHWh'G9
new TestMethod(); k-{yu8*';
} r/UYC"K3
} R'S c
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