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)); C&\5'[*
} g|<Sfp+;+
for(int i=0;i<nEndPos.length-1;i++) H(^bC5'
{ ^cvl:HOog
nEndPos = nStartPos[i+1]; Br>Fpe$q4
} u~zs* qp
nEndPos[nEndPos.length-1] = nFileLength; {Z;t ^:s#
} "%2xR[NF
} ~vdkFc(8B
W{cY6@
`Kl`VP=c
//启动子线程 }A$WO{2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s Wjy6;
for(int i=0;i<nStartPos.length;i++) ({}(qm
{ vdoZ&Tu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )wXuwdc[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CR<`ZNuWz
nStartPos,nEndPos,i); v{x{=M]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -]G(ms;}/Y
fileSplitterFetch.start(); HHk)ZfWRo
} Y]aW)u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6X g]/FD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }*U[>Z-eO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2Nc>6
nEndPos = " + nFileLength); @{ ;XZb^
// fileSplitterFetch[nPos.length-1].start(); :B*}^g
OU DcY@x~
^ ?hA@{T/1
//等待子线程结束 N^?9ZO
//int count = 0; Wk;5/
//是否结束while循环 iP~,n8W
boolean breakWhile = false; *y[PNqyd
%T`U^Pnr
s0UFym8
while(!bStop) qd@&59zSh
{ )4Q?aMm
write_nPos(); |w}w.%
Utility.sleep(500); .]4W!])9
breakWhile = true; em@EDMvI
/G{_7cb
JwnAW}=
for(int i=0;i<nStartPos.length;i++) 3M*Bwt;F_
{ }w-wSkl1
if(!fileSplitterFetch.bDownOver) G1T^a>tj4
{ Q'apG)0I
breakWhile = false; 8 }'|]JK
break; 3. WF}8
} =H7xD"'%R
} `rY2up#%
if(breakWhile) g8;D/
break; mo]KCi
}$su4A@0
y k161\
//count++; )(Iy<Y?#
//if(count>4) Tm]nEl)_
// siteStop(); yTM{|D]$(
} F-Z%6O,2
?^HfNp9
a.F Al@Br
System.err.println("文件下载结束！"); )8gGv
} sE(HZR1
catch(Exception e){e.printStackTrace ();} 8Ad606
} A!W0S
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m"tOe?
//获得文件长度 >v;8~pgO
public long getFileSize() CCijf]+
{ JM$.O;y -
int nFileLength = -1; nHFrG =o,
try{ R_P}~l
URL url = new URL(siteInfoBean.getSSiteURL()); &Jc_Fc(M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -XoPia2
httpConnection.setRequestProperty("User-Agent","NetFox"); ytEC
6"T['6:j
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int responseCode=httpConnection.getResponseCode(); UO`;&e-DB
if(responseCode>=400) AtS;IRN@
{ z:Sigo_z[
processErrorCode(responseCode); H2gj=krK
return -2; //-2 represent access is error {aKqXL[UP
} F#|O@.tDG
`XTh1Z\
Upl6:xYrG
String sHeader; |rRO@18dA
fr6^nDY
_Yb_D/
for(int i=1;;i++) j'%4{n
{ iItcN;;7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4\t1mocCSN
//Utility.log(in.readLine()); W~T}@T:EN
sHeader=httpConnection.getHeaderFieldKey(i); #PvB/3
if(sHeader!=null) !{,F~i9
{ EC&@I+'8Q
if(sHeader.equals("Content-Length")) co4h*?q
{ n#Dv2 E=6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y>."3*^
break; :S@1
} w^k;D,h
} }]1BO
else \h<BDk*
break; 89}Y5#W
} gE/Tj$
} ',7??Q7j&v
catch(IOException e){e.printStackTrace ();} ?VU(Pq*`
catch(Exception e){e.printStackTrace ();} .k{ j]{k
u#7+U\
2g{)AtK$#
Utility.log(nFileLength); vY|^/[x#B
p4>$z& _
#h!*dj"
return nFileLength; 9ch#}/7B
} Z[!d*O%R_
q}Z3?W
T70QJ=,
//保存下载信息（文件指针位置） FxG7Pk+=
private void write_nPos() 6Z?j AXGSq
{ @xsP5je]
try{ |xr%6 [Ff
output = new DataOutputStream(new FileOutputStream(tmpFile)); n@C~ev@%S
output.writeInt(nStartPos.length); _;A $C(
for(int i=0;i<nStartPos.length;i++) ~Aad9yyi
{ Nb2Qp K
// output.writeLong(nPos); 9&%fq)gS
output.writeLong(fileSplitterFetch.nStartPos); 6!iJ;1PeE
output.writeLong(fileSplitterFetch.nEndPos); /T^ JS
} F,Xo|jjj
output.close(); ek aFN\
} cR-~)UyrO
catch(IOException e){e.printStackTrace ();} Ax3W2s
catch(Exception e){e.printStackTrace ();} pb60R|k
} (<t_Pru
/e\{
z!QDTIb
//读取保存的下载信息（文件指针位置） t-u|U(n
private void read_nPos() =bh*[,-
{ ~H)4)r^
try{ "i.r@<)S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nm$Dd~mxW1
int nCount = input.readInt(); d&cU*
nStartPos = new long[nCount]; SQsSa1
nEndPos = new long[nCount]; SDG-~(Y
for(int i=0;i<nStartPos.length;i++) x)rlyjFM
{ ? Q@kg
nStartPos = input.readLong(); PMsz`
nEndPos = input.readLong(); XB hb`AG
} q"KnLA(
input.close(); T@wcHg
} :Br5a34q
catch(IOException e){e.printStackTrace ();} a^qNJ?R!
catch(Exception e){e.printStackTrace ();} Y-piL8Xc
} 6TWWlU^e
5 v^yQ<70
$!vxVs9n
private void processErrorCode(int nErrorCode) I|oT0y&
{ 31^cz*V
System.err.println("Error Code : " + nErrorCode); <q)4la
} Dq\ Jz~
>>l`,+y
%x;x_
//停止文件下载 LL^q1)o
public void siteStop() ?B@;QjhjiJ
{ ;:S&F
bStop = true; e/_C
for(int i=0;i<nStartPos.length;i++) s6*ilq1
fileSplitterFetch.splitterStop(); uaw~r2
)'4P.>!!aQ
Mpue
} _R|Ify#J
} yZ]:y-1
//负责部分文件的抓取 9L0GLmLk1u
**FileSplitterFetch.java vgIpj3u
*/ 4nfu6Dq
package NetFox; g3n'aD@'x
[$(%dV6O
->z54 T
import java.io.*; 8eIUsI.o
import java.net.*; g]@(E
mM.*b@d-
`cz2DR-"
public class FileSplitterFetch extends Thread { &adI (s~
c'6g*%2k
TQX)?^Ft
String sURL; //File URL #v#<itfFH
long nStartPos; //File Snippet Start Position GY3Wj
long nEndPos; //File Snippet End Position l:;PXy6)
int nThreadID; //Thread's ID e<7.y#L
boolean bDownOver = false; //Downing is over +[@z(N-h
boolean bStop = false; //Stop identical TlL^7f}
FileAccessI fileAccessI = null; //File Access interface c@[:V
0<"k8 k@J
J2q,7wI#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :Eh\NOc_O
{ |@?%Ct
this.sURL = sURL; mOpTzg@
this.nStartPos = nStart; r;9 r!$d
this.nEndPos = nEnd; pA.J@,>`}
nThreadID = id; wHZW `
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <H3ezv1M
} uY_SU-v
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j.~!dh$mg
public void run() i"zuil
{ g 6]epp[8
while(nStartPos < nEndPos && !bStop) ZN"j%E{d
{ rrg96WD
:.(;<b<\
CO-_ea U(
try{ )}Q(Tl\$
URL url = new URL(sURL); J{[n?/A{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WPZ?*Sx
httpConnection.setRequestProperty("User-Agent","NetFox"); i| \6JpNA:
String sProperty = "bytes="+nStartPos+"-"; jA".r'D%
httpConnection.setRequestProperty("RANGE",sProperty); YDC mI@
Utility.log(sProperty); 4?N8R$
r|4t aV&
PFUO8>!pA\
InputStream input = httpConnection.getInputStream(); ,F&g5'
//logResponseHead(httpConnection); >+. (r]
+% /s*EC'w
fQrhsuCrC
byte[] b = new byte[1024]; y(R? ,wa=]
int nRead; Li*eGlId
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OY[e.N t&
{ aA7=q=
nStartPos += fileAccessI.write(b,0,nRead); |AZg*T3:W
//if(nThreadID == 1) Vcd.mE(t%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B?VhIP e
} p=/m
Kn+S,1r
H>r!i4l
Utility.log("Thread " + nThreadID + " is over!"); zy*/T>{#
bDownOver = true; "#mBcQ;QLV
//nPos = fileAccessI.write (b,0,nRead); cj11S>D
} ?UM*Xah
catch(Exception e){e.printStackTrace ();} 4Llo`K4
} VDTcR
} c8Z wr]DF
UH7jP#W%=
oyo(1>
//打印回应的头信息 -i-?.:
public void logResponseHead(HttpURLConnection con) 8p[)MiC5W^
{ RK w$-7O
for(int i=1;;i++) boG_f@dv(
{ P2Vg4
String header=con.getHeaderFieldKey(i); G[jW<'f
if(header!=null) Z"unF9`"1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;c$J=h]
Utility.log(header+" : "+con.getHeaderField(header)); $XoQ]}"O
else k4 F"'N
break; .F+@B\A<
} FLEo*9u>b
} @JdZ5Q
NHlk|Y#6b
a&vY!vx3
public void splitterStop() S*yjee<@
{ +^;JS3p@\
bStop = true; n_'{^6*O
} (5\NB0
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} #:SNHM^><
\l~*PG2
*2jK#9"MP
/* B7imV@<
**FileAccess.java @IXsy
*//文件访问(定位，写) {T].]7Z
package NetFox; O$cHZs$
import java.io.*; <tioJG{OT
r7qh>JrO
D_Bb?o5
public class FileAccessI implements Serializable{ T1H"\+
G}p\8Q}'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zl`h~}I
RandomAccessFile oSavedFile; 9?k_y ZV
long nPos; 8U_{|]M
Dl}$pN
mx=BD'
public FileAccessI() throws IOException c/uNM
{ A~mum+[5
this("",0); A@Dw<.&_I
} TiH)5
k!{p7*0
A= w9V
public FileAccessI(String sName,long nPos) throws IOException x,'!eCKN
{ r hfb ftw
oSavedFile = new RandomAccessFile(sName,"rw"); vY_-Ranj#.
this.nPos = nPos; (P`3 @H
oSavedFile.seek(nPos); +$Rt+S BD
} \nP>:5E1
0P]E6hWgg
iJ~Vl"|m
public synchronized int write(byte[] b,int nStart,int nLen) Ox@P6|m
{ *2GEnAZb7n
int n = -1; ^urDoB:
try{ .(WQYOMl0
oSavedFile.write(b,nStart,nLen); v~Y^r2
n = nLen; :GJ &_YHf
} !3ctB3eJ
catch(IOException e) ki)#d' }
{ M4W5f#C5Ee
e.printStackTrace (); LupkrxV
} wT{nu[=GH*
9WR6!.y#f
<Z/x,-^*<
return n; +U3m#Y)k
} {.?/)
Ct%x&m:
cSm%s
} jt.3P
%?Ev|:i`@
j.@\3'
/* $O5UyKI
**SiteInfoBean.java X<*U.=r)
*/ }3L@J8:D"
package NetFox; NW&b&o
k{Aj^O3gD
C;vtY[}<
public class SiteInfoBean { c=`wg$2:5
z'EajBB\f
}O4^Cc6
private String sSiteURL; //Site's URL w4d--[Q
private String sFilePath; //Saved File's Path s]JF0584
private String sFileName; //Saved File's Name =%BZ9,l
private int nSplitter; //Count of Splited Downloading File @$+ecaVW
.uk>QMs1
go<W( ,O
public SiteInfoBean() ]]wA[c~G
{//nSplitter的缺省值为5 : 7`[$<~E
//default value of nSplitter is 5 Zc`BiLzrIG
this("","","",5); >L 0_dvr
} ]V#M%0:Q82
v3jg~"!
;IokThI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iS<I0\D
{ y7i*s^ys{
sSiteURL= sURL; L# 2+z@g
sFilePath = sPath; HZf/CE9T
sFileName = sName; GJqJlgHe
this.nSplitter = nSpiltter; `u&Zrdr,
KSNPkd6
9*1,!%]
} Ch3jxgQY
7!JQB
#Q`dku%V:
public String getSSiteURL() &E=>Hj(dTG
{ b8LLr;oQw
return sSiteURL; vsl]92xI
} ]@Uq=?%
{>)#HD
X'qU*Eo
public void setSSiteURL(String value) ?pB>0b~3-
{ d*%`!G
sSiteURL = value; csW43&
} ]n~ilS.rkl
< RH UH)I
T r1?620
public String getSFilePath() DuHu\>f<S
{ q;][5
return sFilePath; ry`z(f
} /Id%_,}Kb
?}U(3
gh8F2V;<
public void setSFilePath(String value) 6U R2IxbE
{ 2 Cv4=S
sFilePath = value; n' q4
} ap+JQ@b
.Lsavpo
xY^%&n
public String getSFileName() e(GP^oK
{ UZJCvfi
return sFileName; 'DL`Ee\
} [Q/TlOt5
li}1S
P;ci9vk
public void setSFileName(String value) IV\'e}
{ [nrYpb4
sFileName = value; =06gj)8
} ZOeQ+j)|I
<YhB8W9 P
$',K7%y
public int getNSplitter() iiS-9>]/
{ ,>0*@2
return nSplitter; /7|V+6jV
} DkvF5c&
3@M|m<_R$
\%f q
public void setNSplitter(int nCount) XH}\15X
{ x:7b/j-
nSplitter = nCount; &h^9}>rVjV
} 1+jAz`nA:T
} 34%RZG_o'
l0PZ`m+;j
4,CXJ2
/* S~;4*7+?:
**Utility.java > dI LF
*/ DVB{2~7 4
package NetFox; _/6!yyl
--%N8L;e
{MCi<7j<?
public class Utility { X\@C.H2ttY
V C24sU
1DE<rKI
public Utility() 2[RoxKm
{ tG9BfGF
aTqd@},?
*n 6s.$p)%
} t>urc
M^r1S
//线程睡眠 [z`31F
public static void sleep(int nSecond) j3{I /m
{ G~2jUyv
try{ }L+L"l&
Thread.sleep(nSecond); %|g>%D3Z?
} X(]WVCu
catch(Exception e) A: 5x|
{ (e!0]Io@
e.printStackTrace (); njScz"L~
} ^;Y|3)vvB
} % NA9{<I
E:JJ3X|
//日志 VY;{/.Sa
public static void log(String sMsg) )vjh~ybZ
{ 6:Ch^c+IZ
System.err.println(sMsg); x(etb<!jd
} wQP^WzNE
V5sg#|&
s%C)t6`9
public static void log(int sMsg) CFzNwgv]z
{ \r /ya<5
System.err.println(sMsg); m?pstuUK(
} 5][Ztx
} \`oT#|0
xO^:_8=&:
Vr6@>@SC
/* I/d&G#:~
**TestMethod.java v, n$^R
*/ ,&jhlZ i
package NetFox; *)ardZV${
gVq;m>\|F
:3XA!o&.T3
public class TestMethod { YQ+tDZY8`
K/tRe/t}
(qqOjz
public TestMethod() F~%]6^$w
{ ///xx/weblogic60b2_win.exe 4 Y;Nm1@
try{ & -{DfNKc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i5Zk_-\#H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :=/85\P0SU
SiteFileFetch fileFetch = new SiteFileFetch(bean); %+8F'&X
fileFetch.start(); Q<h-FW8z
} TD'L'm|2
catch(Exception e){e.printStackTrace ();} 0vEoGgY0*:
0Fk5kGD,&K
8TGOx%}i
} AvxfI"sp
`tHvD=`m.
^* J2'X38I
public static void main(String[] args) fBRo_CU8!
{ XWA:J^
new TestMethod(); M)eO6oX|
} }`W){]{kO
} 19O,a#{KHf
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