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)); 0ZD)(ps|
} sjLm-pn3
for(int i=0;i<nEndPos.length-1;i++) xzx~H>M
{ 6e,IjocsB
nEndPos = nStartPos[i+1]; mbhh
} |w~*p N0
nEndPos[nEndPos.length-1] = nFileLength; (:H4
} M?sTz@tqq
} .pxUO3g
FS)C<T]t
8rBa}v9
//启动子线程 &-IkM%_A9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S_AN.8T
for(int i=0;i<nStartPos.length;i++) ,{ 0&NX
{ o@$pyU8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I+Qt5Ox
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aY,'^S
nStartPos,nEndPos,i); @GweNo`p7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hE\gXb
fileSplitterFetch.start(); (3x2^M8
} [ x.]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]~3a~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;&w_.j*Is
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n[a%*i6x
nEndPos = " + nFileLength); hE,-CIRg
// fileSplitterFetch[nPos.length-1].start(); ^8ilUu
#8vl2qWbi
-idbR[1{?
//等待子线程结束 T-s[na(/L
//int count = 0; `P|V&;}K
//是否结束while循环 *g'%5i1ed
boolean breakWhile = false; (L1O;~$
/_(l:q^
=td(}3|D Y
while(!bStop) S}/ZHo
{ Y)S f;
write_nPos(); ?$\sMkn
Utility.sleep(500); PEtr8J$uB
breakWhile = true; 5}9rpN{y
<pT1p4T<
Y!u">M#@
for(int i=0;i<nStartPos.length;i++) dqt}:^L*0g
{ .zW.IM}Z
if(!fileSplitterFetch.bDownOver) >6(e6/C-9
{ \Z/0i|
breakWhile = false; {oo(HD;5
break; }&Xf<6
} 2mthUq9b*
} Hb$wawy<
if(breakWhile) J rYL8 1
break; cKwmtmwB
nl-tJ.MU"
L6=5]?B=
//count++; d\ 7OtM
//if(count>4) 8f&#WIZ
// siteStop(); uF*tlaV6
} :G<~x8]k0
gHvkr?Cg
wD pL9q
System.err.println("文件下载结束！"); XPi5E"
} NQbgk+&wD
catch(Exception e){e.printStackTrace ();} Es:oXA
} EF6"PH+J@
mFC9\
@G>&Gu;5
//获得文件长度 Oh1a'&
public long getFileSize() i@YM{FycX
{ &xFs0Ri(
int nFileLength = -1; OBM&N
try{ 8;,(D#p
URL url = new URL(siteInfoBean.getSSiteURL()); `C*psS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ARB^]
httpConnection.setRequestProperty("User-Agent","NetFox"); <5c^DA
M1Th~W9l
p!LaR.8]
int responseCode=httpConnection.getResponseCode(); u&Xn#fh
if(responseCode>=400) ^12}#I
{ LtDGu})1
processErrorCode(responseCode); +227SPLd
return -2; //-2 represent access is error !?{%9
} C #@5:$
S)@) @3
_~b]/]|z#N
String sHeader; Bp=BRl
Y]}>he1/5
M ~6k[ew
for(int i=1;;i++) Ot!*,%sjQ
{ <;E>1*K}8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z#_VxA>]v
//Utility.log(in.readLine()); $olITe"$g
sHeader=httpConnection.getHeaderFieldKey(i); XV<{tqa
if(sHeader!=null) YksJ$yH^
{ >56;M7b(K
if(sHeader.equals("Content-Length")) ==W] 1@s
{ [iG4qI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); URxy*)
break; {F$MZ2E
} Gc:oSvm
} }zwHUf9q1
else MB(l*ju0
break; l$!g#?w
} oIY@xuj
} ulY<4MN
catch(IOException e){e.printStackTrace ();} JsQmn<Yt
catch(Exception e){e.printStackTrace ();} v0~*?m4
JI~@H /j
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Utility.log(nFileLength); :eTzjW=
'ul~f$ V
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return nFileLength; k3B]u.Lo
} ~_yz\;#
Z=/bD*\g
|^kfa_d
//保存下载信息（文件指针位置） mwqe@7
private void write_nPos() GH6ozWA
{ }?z_sNrDk
try{ 0%hOB:
output = new DataOutputStream(new FileOutputStream(tmpFile)); !PY.FnZ
output.writeInt(nStartPos.length); bp(X\:zAy
for(int i=0;i<nStartPos.length;i++) "+ 8Y{T
{ ?Kf?Z`9 *Y
// output.writeLong(nPos); ^U@Erc#d
output.writeLong(fileSplitterFetch.nStartPos); ;1woTAuD
output.writeLong(fileSplitterFetch.nEndPos); wWUt44:0O
} P}C;%KzA
output.close(); `Ot;KDz
} YumHECej
catch(IOException e){e.printStackTrace ();} hj-#pL-t
catch(Exception e){e.printStackTrace ();} x[H9<&)D
} %'i`Chc^!;
&o*f*(C2
w 7 j hS
//读取保存的下载信息（文件指针位置） g6T /k7a
private void read_nPos() 1W2hd!J7C
{ SAw. 6<Wy-
try{ _0]{kB.$_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B[6y2+6$0
int nCount = input.readInt(); M%Dv-D{
nStartPos = new long[nCount]; qHQ#^jH
nEndPos = new long[nCount]; )o@-h85";
for(int i=0;i<nStartPos.length;i++) }CXL\,;
{ _^pg!j[Fy}
nStartPos = input.readLong(); =M+enSu
nEndPos = input.readLong(); hA_Y@&=W
} YF<;s^&@u
input.close(); QO%#.s
} ~Uw<E:?v
catch(IOException e){e.printStackTrace ();} ~$3X>?Q
catch(Exception e){e.printStackTrace ();} V$XCe
} X$4 5<oz
aI0}E O
j?rq%rQd
private void processErrorCode(int nErrorCode) ~%o?J"y
{ jI9Kn41
System.err.println("Error Code : " + nErrorCode); B^u qu
} 9&uWj'%ia
(VzabO
}28,fb /
//停止文件下载 ROB/#Td
public void siteStop() 92HxZ*t7km
{ d;10[8:5=
bStop = true; g` QbJ61a
for(int i=0;i<nStartPos.length;i++) ]ZOzqh_0C
fileSplitterFetch.splitterStop(); `CXAE0Fx
E _DSf
SecZ5(+=
} zS##YR
} +WP
//负责部分文件的抓取 =9ISsI\Y6
**FileSplitterFetch.java D.\s mk
*/ K6Gri>Um
package NetFox; fhZD[m#D
;0f?-W?1
3Vj,O?(Z
import java.io.*; On{p(|l
import java.net.*; V=,VOw4
,3`RM$
$zvqjT:>
public class FileSplitterFetch extends Thread { $|yO mh
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y-iuOzq4
String sURL; //File URL \y G//
long nStartPos; //File Snippet Start Position HFL(t]
long nEndPos; //File Snippet End Position ,!RbFME&H
int nThreadID; //Thread's ID Iq-+X3i
boolean bDownOver = false; //Downing is over ,^UNQO*{GI
boolean bStop = false; //Stop identical mzl %h[9iI
FileAccessI fileAccessI = null; //File Access interface SH/KC
do:3aP'S,
62X;gb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _bO4s#yI
{ IW.~I,!x
this.sURL = sURL; 0V&6"pF_Y'
this.nStartPos = nStart; ]`2=<n;=
this.nEndPos = nEnd; 62 biOea
nThreadID = id; q{W@J0U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;(0E#hGN
} +h$)l/>:
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2Rp5 E^s
public void run() j<LDJi>O
{ |\OG9{q
while(nStartPos < nEndPos && !bStop) OBY
{ Q( C\X
]~SOGAFW
JPX5Jm()
try{ 'o#ve72z1
URL url = new URL(sURL); D#T1~r4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d+Vx:`tT
httpConnection.setRequestProperty("User-Agent","NetFox"); :{d?B$
String sProperty = "bytes="+nStartPos+"-"; nSL x1Q
httpConnection.setRequestProperty("RANGE",sProperty); _[,oP s:+
Utility.log(sProperty); 'Zdjd]
1{sfDw[s
/OpVr15
InputStream input = httpConnection.getInputStream(); zd+_ BPT
//logResponseHead(httpConnection); ;MqH)M
cj:!uhZp7
y/ #{pyJ
byte[] b = new byte[1024]; *jps}uk<
int nRead; (P-Bmu!s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mE"?{~XVL
{ (YbRYu
nStartPos += fileAccessI.write(b,0,nRead); S[bFS7[
//if(nThreadID == 1) j#TtY|Po
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +K3SAGm
} /=zzym~<>
S?bG U8R5
ab1qcQ<
Utility.log("Thread " + nThreadID + " is over!"); EPQ~V
bDownOver = true; R(c:#KF#8
//nPos = fileAccessI.write (b,0,nRead); d85\GEF9i
} r?s,
catch(Exception e){e.printStackTrace ();} 8\BCC1K
} >4A~?=
} ,1"w2,=
H*DWDJxmV
:RsO$@0G
//打印回应的头信息 l@8UL</W
public void logResponseHead(HttpURLConnection con) X`dd"8%
{ |=7ouFl
for(int i=1;;i++) 2l)J,z
{ K +oFu%
String header=con.getHeaderFieldKey(i); S+Aq0B<
if(header!=null) 5YlY=J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DlkHE8r\
Utility.log(header+" : "+con.getHeaderField(header)); m]yt6b4
else Y~qv 0O6K
break; KKR@u(+"a
} _R!KHi
} x<'(b7{U0
k\T,CZ<
}*{@-v|_R
public void splitterStop() "#4p#dM0e
{ D{&0r.2F
bStop = true; 8#OcrJzC
} ~:Jw2 P2z
'2u(fLq3h
cSYW)c|t
} sE4=2p`x
HSk gS
Y"GU"n~
/* I*/?*p/I
**FileAccess.java ?j^[7
*//文件访问(定位，写) IR(6
package NetFox; o0Z(BTO
import java.io.*; +?[,y
78v4cQ Y
lMu}|d
public class FileAccessI implements Serializable{ 289@O-
pu(a&0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 03ol!|X"9
RandomAccessFile oSavedFile; as1ZLfN.
long nPos; (nk)'ur.
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*xEcX6ZHX
public FileAccessI() throws IOException $]4>;gTL'
{ }QszOi\fV1
this("",0); Yx21~:9}
} :"+/M{qz
%RE-_~GF
wD}ojA&DU
public FileAccessI(String sName,long nPos) throws IOException D];%Ey
{ ,6,sz]3-
oSavedFile = new RandomAccessFile(sName,"rw"); 3/P#2&jt
this.nPos = nPos; |wASeZMO2
oSavedFile.seek(nPos); {*VCR
} )J?Nfi%
\ltA&}!
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public synchronized int write(byte[] b,int nStart,int nLen) 2IgTB|2
{ mE3^5}[>
int n = -1; B+G,v:)R6z
try{ {EKzPr/
oSavedFile.write(b,nStart,nLen); cd36f26`"w
n = nLen; 0h~Iua5
} 9$&+0
catch(IOException e) cPh U qET
{ H6ff b)&
e.printStackTrace (); U$[C>~r
} v:*t5M >
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}cK<2J#
return n; .\kcWeC\
} 2BLcun
7\sJ=*
D8a[zXWnc
} 5BvCP
P q\m8iS,w
Mp:/[%9Fi
/* 0MK|spc
**SiteInfoBean.java G1 ?."
*/ +8e~jf3E1
package NetFox; | ,bCYK
__p\`3(,'
E DuLgg@
public class SiteInfoBean { Qe=,EXf
k!e \O>+
2|vArRKt
private String sSiteURL; //Site's URL >}#h
private String sFilePath; //Saved File's Path &61;v@
private String sFileName; //Saved File's Name 7Y$#* 7
private int nSplitter; //Count of Splited Downloading File "4c ?hH:C
Ue:'55
{R[FwB^7wJ
public SiteInfoBean() F|K=].
{//nSplitter的缺省值为5 rn^7B-V
//default value of nSplitter is 5 e0O2>w
this("","","",5); Z%3]
} Ekx3GM_]
o]0v#2l'
_6a+" p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K~"J<798{
{ ncg5%(2
sSiteURL= sURL; (Dr g
sFilePath = sPath; IUco 8
sFileName = sName; Nx~9Ug
this.nSplitter = nSpiltter; xaO9?{O
TJ@@kSSbl
3F'{JP
} H`/QhE
W=T3spV
^6!C":f
public String getSSiteURL() laX(?{_
{ NG-Wn+W@b
return sSiteURL; fY@Y$S`Fh
} yjZ]_.
1iq,Gd-G.
<7HVkAa
public void setSSiteURL(String value) J&4QI( b.
{ S pxkB!
sSiteURL = value; c$),/0td|
} {6%vmMbJ
Fj\}&H*+
%,$Ms?,n`
public String getSFilePath() Bq~!_6fB
{ -<kl d+
return sFilePath; 2Y_ `&
} @xKLRw
!'>(r K$
>$,A [|R
public void setSFilePath(String value) &V7@ TZ
{ }} cz95
sFilePath = value; E~?0Yrm F
} f}q4~NPn-
,]?Xf>
H.EgL@;mb
public String getSFileName() &6fNPD(|
{ *Dr-{\9
return sFileName; 12 HBq8o
} `]^0lD=eI
}qy,/<R
~m^.&mv3/
public void setSFileName(String value) ~ZeF5
{ 85; BS'
sFileName = value; ' uvTOgP,
} Rd6? ,
3R(GO.n=]
8hWBTUN
public int getNSplitter() DQ7+
{ USz|Rh
return nSplitter; ;xFx%^M}br
} {~.~ b+v
"&jA CI
)%rGD =2~
public void setNSplitter(int nCount) *yJCnoF
{ oTOr,Mn0\6
nSplitter = nCount; ?>b>LDpx?
} L><# I
} WP,Ll\K)7
{awv=s
/ fBi9=}+
/* q{v:T}Q|A
**Utility.java D=}UKd
*/ %H=d_Nm{
package NetFox; YXE?b@W"
X`km\\*
lz>YjK:
public class Utility { ^VsX9
~!( (?8"
+2%ih!
public Utility() ?E1<>4S8
{ P" +!mSe^~
/DOV/>@5%
&u5OL?>
} hE>ux"_2/
C^ngdba\
//线程睡眠 \l^L?69
public static void sleep(int nSecond) :^7P. lhK
{ e?W-vi%
try{ UObI&*2
Thread.sleep(nSecond); `"CIy_m
} )eFXjnHN
catch(Exception e) #clOpyT*
{ ~B!O X
e.printStackTrace (); 9kmEg$WM
} 0zrgK;9
} DG& ({vy
(XtN3FTY
//日志 z%xWP&3%"
public static void log(String sMsg) IS *-MLi
{ v~|~&Dwq
System.err.println(sMsg); |l\&4/SJ
} &R$6dG4
Ewjzm,2
N{L'Q0!
public static void log(int sMsg) H&K(,4u^
{ i}cqV B?r
System.err.println(sMsg); 9>gxJ7pY
} r{y&}gA
} qYD$_a
}Rujh4*
~{GbuoH
/* r!H'8O!
**TestMethod.java m80e^
*/ G-`4TQ
package NetFox; Y~ j.Kt
(Fc\*Vn
2$=U#!OtU
public class TestMethod { tHF-OarUO
B|%(0j8
,(d\!T/]'
public TestMethod() : utY4
{ ///xx/weblogic60b2_win.exe ?y1']GAo
try{ AY]dwKw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O@*7O~eO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); USF9sF0l
SiteFileFetch fileFetch = new SiteFileFetch(bean); Leg)q7n
fileFetch.start(); >uVo'S.
} ~s.~X5
catch(Exception e){e.printStackTrace ();} Yj%hgb:)
i?+ZrAx>
?:@13wm
} |wF_CZ*1
q-7C7q
+tsF.Is!t
public static void main(String[] args) R]{zGFnx
{ \o-9~C\c*
new TestMethod(); W5C8$Bqm
} -Jqm0)2
} BE,XiH;
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