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)); F:DrX_O%
} _)-o1`*-
for(int i=0;i<nEndPos.length-1;i++) \fe]c :
{ d#wVLmKZ
nEndPos = nStartPos[i+1]; q@2siI~W
} f*8DCh!r"
nEndPos[nEndPos.length-1] = nFileLength; /Z4et'Lo
} Dvln/SBk
} 69.NPy@
TD_Oo-+\
<#HYqR',
//启动子线程 hE-M$LmN@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /qw.p#
for(int i=0;i<nStartPos.length;i++) QS`]
{ 1h5 Akq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C7AUsYM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }(u ol
nStartPos,nEndPos,i); 9N3eN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gQ.Sa j $
fileSplitterFetch.start(); FVBYo%Ap
} x,Vr=FB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kU`r)=1"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2J;g{95z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /Ci<xmP
nEndPos = " + nFileLength); ;A[Q2(w+
// fileSplitterFetch[nPos.length-1].start(); $ME)#(
Kc(FX%3LU
0m ? )ROaJ
//等待子线程结束 :BTq!>s
//int count = 0; syK^<xa
//是否结束while循环 TS5Q1+hWHV
boolean breakWhile = false; 3R VR
&+R?_Ooibk
ehY5!D1Q
while(!bStop) Rlirs-WQ
{ :Ux_qB
write_nPos(); HpnWoDM
Utility.sleep(500); Z%\,w(o[h
breakWhile = true; GPkpXVm
#LOwGJ$yVz
40 0#v|b
for(int i=0;i<nStartPos.length;i++) v.5+7,4
{ )dSi/
if(!fileSplitterFetch.bDownOver) 4X|zmr:A
{ xN%K^Tree
breakWhile = false; :\U{_@?`%
break; g=o4Q< #^y
} B7vpsSL
} @s^-.z
if(breakWhile) RpYERAgT
break; o _H`o&xr
)\^-2[;
$,'*f?d
//count++; ~u+9J}
//if(count>4) N}YkMJy
// siteStop(); ~e.L.,4QZ8
} gPc=2
t&DEb_"De
jF*j0PkNdb
System.err.println("文件下载结束！"); 29q _BR *:
} ~F7gP{r
catch(Exception e){e.printStackTrace ();} iG?[<1~
} dC4'{n|7
4xJQ!>6
6S\8$
//获得文件长度 {FTqu.
public long getFileSize() @xZR9Z8]L
{ RCLeA=/N@0
int nFileLength = -1; L&OwPd
try{ 61 ~upQaR
URL url = new URL(siteInfoBean.getSSiteURL()); t&Og$@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BL58] P84
httpConnection.setRequestProperty("User-Agent","NetFox"); xAP+FWyV
$u6 3]rypm
'[O;zJN;
int responseCode=httpConnection.getResponseCode(); h`.&f
if(responseCode>=400) y18Y:)DkL
{ &G$Ucc `
processErrorCode(responseCode); KCDE{za
return -2; //-2 represent access is error W+1^4::+
} B,fo(kG
Jpo(Wl
D7qOZlX16
String sHeader; kz7(Z'pw
4I5Y,g{6+
/JU.?M35
for(int i=1;;i++) Oz#{S:24M+
{ vSLtFMq^(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G<;*SYAb
//Utility.log(in.readLine()); sFTy(A/
sHeader=httpConnection.getHeaderFieldKey(i); ji,kkipY?w
if(sHeader!=null) RY*U"G0#w
{ 5i{j' {_(8
if(sHeader.equals("Content-Length")) EDs\,f}
{ _t}WsEQ+P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B48={
break; $ o#V#
} 8SS|a
} [;sRV<
else HiJE}V;Vq
break; E q+_&Wk
} 7i1q wRv
} 7 x?<*T
catch(IOException e){e.printStackTrace ();} @gXx1hEg
catch(Exception e){e.printStackTrace ();} b*Q&CL
GNJj=1Lsd
R_S.tT!
Utility.log(nFileLength); ?#Q #u|~
lCHO;7YHX
*siFj CN<
return nFileLength; $a ` G
} <yg F(
&XUiKnNW
Yp2eBgo"
//保存下载信息（文件指针位置） >~+ELVB&
private void write_nPos() {P#|zp4C{
{ &Z|P2dI
try{ CQDkFQq-dq
output = new DataOutputStream(new FileOutputStream(tmpFile)); -1ub^feJ,
output.writeInt(nStartPos.length); *bpD`s @
for(int i=0;i<nStartPos.length;i++) 6/dI6C!
{ Tkgs]q79
// output.writeLong(nPos); IRqy%@)
output.writeLong(fileSplitterFetch.nStartPos); 9490o:s
output.writeLong(fileSplitterFetch.nEndPos); )TM4R)r%)9
} 3%=~)7cF
output.close(); zT?D<XW>1
} DrK{}uM
catch(IOException e){e.printStackTrace ();} y Fq&8 x<X
catch(Exception e){e.printStackTrace ();} =[jXe
} hqkz^!rp
\:F_xq
_``=cc
//读取保存的下载信息（文件指针位置） ^@NU}S):yN
private void read_nPos() pIKPXqA
{ ,UdVNA
try{ 4x[S\,20
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !brf(-sr)
int nCount = input.readInt(); t}/( b/VD
nStartPos = new long[nCount]; x`)&J B
nEndPos = new long[nCount]; [Cv/{f3]u{
for(int i=0;i<nStartPos.length;i++) I?G:p+
{ YQA,f#
nStartPos = input.readLong(); Q#[9|A9
nEndPos = input.readLong(); l_%6
} g_COp"!~9
input.close(); Q6I:"2u1
} n#_$\ p>Yd
catch(IOException e){e.printStackTrace ();} | (_
catch(Exception e){e.printStackTrace ();} HT1!5
} A1zjPG&]
"wh ,Ue
q;)JISf.
private void processErrorCode(int nErrorCode) 0v$~90)
{ $z*'fXg
System.err.println("Error Code : " + nErrorCode); T0rGM
} h>OfOx/{q9
85xR2<:
hODWB&b
//停止文件下载 'Ne@e)s9
public void siteStop() 0}quG^%_
{ aPbE;" f
bStop = true; e.V:)7Uc
for(int i=0;i<nStartPos.length;i++) PBkt~=j
fileSplitterFetch.splitterStop(); ,{?%m6.lE
}Y36C.@H
vn"{I&L+w0
} (0y~%J
} WlBc.kFck
//负责部分文件的抓取 oIj#>1~c%
**FileSplitterFetch.java A '];`
*/ {fn!'
package NetFox; :1KpGj*F
9|CN8x-
LOV)3{m
import java.io.*; H\tUpan6fy
import java.net.*; Jz *;q~
\7'{g@C(
$43qME
public class FileSplitterFetch extends Thread { &m:uO^-D
/{--+ C
>]5P 3\AQV
String sURL; //File URL W#WVfr
long nStartPos; //File Snippet Start Position Whf.fK
long nEndPos; //File Snippet End Position _X"N1,0
int nThreadID; //Thread's ID **gXvTqI
boolean bDownOver = false; //Downing is over dQR-H7U
boolean bStop = false; //Stop identical Qhcu>ra
FileAccessI fileAccessI = null; //File Access interface ?]Xpi3k
|R\>@Mg#B
bYQRBi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A#'8Xw|
{ G<rHkt@[
this.sURL = sURL; #d2.\X}A"3
this.nStartPos = nStart; z]D69O b
this.nEndPos = nEnd; FZE"7ec>m
nThreadID = id; Bad:no\W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O~K>4ax
} tc{sB\&-
!6Mo]xh
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public void run() )*x6 FfTUd
{ u-G+ j)
while(nStartPos < nEndPos && !bStop) Jd^,]
{ GKc`xIQ
Qtv&ijFC
i5?q,_
try{ h Pa_VrH
URL url = new URL(sURL); I->Ss},U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qfRH5)k
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 -RsnF
String sProperty = "bytes="+nStartPos+"-"; 6h,(wo3Y
httpConnection.setRequestProperty("RANGE",sProperty); j@uOOhy
Utility.log(sProperty); e@* EzvO
?\s+EE&-
/9pwZ%:<
InputStream input = httpConnection.getInputStream(); !fR3(=oN
//logResponseHead(httpConnection); +8d1|cB"
l(tOe
Z+. '>
byte[] b = new byte[1024]; #O} ,`[<
int nRead; 0-yp,G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .j<]mUY
{ TXvI4"&
nStartPos += fileAccessI.write(b,0,nRead); K\6u9BYG
//if(nThreadID == 1) !sW(wAy?o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s %\-E9 T
} [o+q>|q
y0.8A-2:
.Cl:eu,]
Utility.log("Thread " + nThreadID + " is over!"); !1{e|p 7
bDownOver = true; q0R -7O(
//nPos = fileAccessI.write (b,0,nRead); ,a]?S^:y]
} NDlF0f
catch(Exception e){e.printStackTrace ();} q]e`9/U
} O%KsD[W;
} (~wqa 3
X1-'COQS%&
g+>(dnX
//打印回应的头信息 qUGC"<W
public void logResponseHead(HttpURLConnection con) };jN\x?&q
{ (VEpVn3{
for(int i=1;;i++) eMY<uqdw
{ ah0`KxO]
String header=con.getHeaderFieldKey(i); xQXXC|T
if(header!=null) 8hJ%JEzga
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RA'M8:$
Utility.log(header+" : "+con.getHeaderField(header)); $jI3VB
else >$7v ;Q
break; f"SD/]q-
} m\r@@!
} ![_*(8v}S
\T:i{.i
6BbGA*%{
public void splitterStop() |G,tlchprs
{ "(z5{z?S
bStop = true; vyX\'r.~7
} r6} |hpJ8
Q)"Nu.m &
c[4i9I3v
} VE{3}S
EGzzHIZ`!
(b~T]3Es
/* 6ZG+ZHUC&
**FileAccess.java !1DKLQ
*//文件访问(定位，写) nv%rJy*w[
package NetFox; fW3(&@
import java.io.*; I]<_rN8~o
B!_mC<*4`X
#W'HR
public class FileAccessI implements Serializable{ > BY&,4r
1&)?JZhg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nvJf/90$
RandomAccessFile oSavedFile; ]?+p5;{y4
long nPos; !K}~/9Z=m
(ehK?6[
`W:%mJd9
public FileAccessI() throws IOException >x+6{^}Q>
{ o` ZQd,3
this("",0); Avd ^
} )d1_Wm#B
,PuL{%PXu
r1.nTO%
public FileAccessI(String sName,long nPos) throws IOException )ufg9"\
{ luuX2Mx>o
oSavedFile = new RandomAccessFile(sName,"rw"); "2P&X
this.nPos = nPos; WEQ1 Seq
oSavedFile.seek(nPos); +HeTtFo{M
} /F-qP.<D,r
57zSu3v4Y
[los dnH^?
public synchronized int write(byte[] b,int nStart,int nLen) -o[x2u~n\
{ =;3Sx::=
int n = -1; ?_$=l1vf
try{ y?m/*hh`
oSavedFile.write(b,nStart,nLen); G_{&sa
n = nLen; 6@e+C;j=
} 8U>B~9:JO
catch(IOException e) L[H5NUG!
{ KJ=6n%6
e.printStackTrace (); ^xHTWg%9
} v'qG26
Co9QW/'i
hMUs" <.
return n; GCX G/k?w:
} #Jn_c0
p|jV{P
Wi2WRJdyu
} ,^;)<[
=aA+~/~8%
=aj/,Q]
/* X*39c b(b
**SiteInfoBean.java ng:9 l3x
*/ ph[#QHB
package NetFox; wS+^K
Q`D~5ci
YW`,v6
public class SiteInfoBean { (TwnkXrR,
"@d[h,TM
wsN?[=l{s
private String sSiteURL; //Site's URL /VzI'^
private String sFilePath; //Saved File's Path IOoz^/'
private String sFileName; //Saved File's Name j!4et;
private int nSplitter; //Count of Splited Downloading File a1.Ptf eW|
_$f9]bab
]*FVz$>XM
public SiteInfoBean() vj\dA2!~
{//nSplitter的缺省值为5 U{z9>
//default value of nSplitter is 5 *@Y3oh}S
this("","","",5); 6s\Kt3=
} .k9{Yv0
7J|VD#DE$Y
I8<,U!$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !+4cqO
{ 079'(%
sSiteURL= sURL; H(2]7dRS%
sFilePath = sPath; Xn,v]$M!
sFileName = sName; k.^coI5
this.nSplitter = nSpiltter; (+u39NQV
J-) XQDD
\XM^oE#G
} ZAUQJS 91E
;._7jFj.
8&~~j7p,
public String getSSiteURL() k^%B5
{ )m{Ye0!RD
return sSiteURL; AUNQA
} m-DsY
P=&o%K,:f
9Xl5@%uz?z
public void setSSiteURL(String value) &jczO-R^
{ +|@rD/I6
sSiteURL = value; l)w Hl%p
} J.dLPKU;-
t|!j2<e
t" 7yNs(I
public String getSFilePath() .G(llA}
{ f0<%&2ym
return sFilePath; ]oV{t<0a
} QgD g}\P
P=+nB*hG
]%Nlv(
public void setSFilePath(String value) H_Kj7(=&>
{ ?wF'<kEH
sFilePath = value; |),'9
} +sx 8t
J}@z_^|"mJ
VY"9?2?/
public String getSFileName() Ra/Ukv_v
{ RJH,
return sFileName; .8uz 6~
} bY2 C]r(n
_s$_Sa ;
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public void setSFileName(String value) mVsIAC$}8
{ drd/jH&
sFileName = value; )r z+'|,
} /c-r
^/=#UQ*k
b}wC|\s
public int getNSplitter() k({\/t3i
{ 3 M10fI?
return nSplitter; pD2<fP_
} 2gjGeM
Gqcz<=/
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public void setNSplitter(int nCount) zT|)uP*
{ 9cx =@
nSplitter = nCount; o/ mF#
} :BukUket1e
} he-Ji
+"}=d3E6
q4$+H{xB
/* F3lw@b3])
**Utility.java xc:!cA{V
*/ -;XKcS7Ue
package NetFox; Hiv!BV|
y}K\%;`[a
s(LT
public class Utility { ~i_Tw#}
(j"(
Rek -`ki5F
public Utility() "ZHtR/;
{ \[>9UC%
FvuGup`w
bo=ZM9
} !.<T"8BUpv
H,<7G;FPT
//线程睡眠 g3sUl&K
public static void sleep(int nSecond) b7\ cxgRq
{ \zkw2*t
try{ $hVYTy~}
Thread.sleep(nSecond); ]PP:oriWl
} 4YMX|1wd)
catch(Exception e) )Vk6;__
{ ";w}3+R
e.printStackTrace (); #W2[
} Y'3}G<'%
} asgF1?r
]G}B 0u3
//日志 's!-80sd
public static void log(String sMsg) ExXM:1 e26
{ _uu<4c
System.err.println(sMsg); cj|*_}
} u%dKig
$7Mtt.d6
>71&]/Rv
public static void log(int sMsg) PS" .R_"
{ wFIh6[3
System.err.println(sMsg); KZ:8[d
} /<3<. ~
} geefnb
2~p[7?sp'
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/* FM5e+$>@
**TestMethod.java ql&*6KZ"
*/ zN_:nY>
package NetFox; mN5 8r"!J
X7|.T0{=x
7C?.L70ZY
public class TestMethod { MuEy>dl
nxap\Lf
m>e3vu
public TestMethod() z&3]%t `C
{ ///xx/weblogic60b2_win.exe N<_Ko+VF
try{ snp v z1iS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )06iV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zq ot{s
SiteFileFetch fileFetch = new SiteFileFetch(bean); )yb+M ez
fileFetch.start(); SHqyvF
} 6=PiVwI
catch(Exception e){e.printStackTrace ();} 4DO/rtkVq
VAYb=4lt
#G,XDW2"w
} xwzT#DXGJ
Rh] P8
{R&ZqEo'D
public static void main(String[] args) ;? uC=o>Z{
{ _NdLcpBT?
new TestMethod(); OalP1Gy
} 2+92Q_+
} D\T!4q'Q
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