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)); ~yi&wbTjM
} \!QF9dP4
for(int i=0;i<nEndPos.length-1;i++) =Yj[MVn
{ lkZC?--H
nEndPos = nStartPos[i+1]; 5 WppV3;
} 5tU"|10m3
nEndPos[nEndPos.length-1] = nFileLength; 5)zB/Ta<
} nTU~M~gky
} ?03Zy3/
(d;(FBk='
iy82QNe
//启动子线程 'c[LTpn4=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t4k'9Y:\Q
for(int i=0;i<nStartPos.length;i++) <PN;D#2bh
{ />[6uvy#Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4)iEj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <e&QTyb
nStartPos,nEndPos,i); 'TrrOq4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G r|@CZq
fileSplitterFetch.start(); I=%sDn
} mY8=qkZE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >ij4z N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /V<`L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B^(rUR
nEndPos = " + nFileLength); $l;tP
// fileSplitterFetch[nPos.length-1].start(); DiQkT R
b<(UmRxx3
%B&?D@
//等待子线程结束 I*t)x,~3
//int count = 0; ~9 WJrRWB
//是否结束while循环 ,Q#tA|:8j
boolean breakWhile = false; /Z " 4[
/C"s_:m;3
fF>qU-
while(!bStop) aaugu.9
{ I!7.fuO
write_nPos(); 70 UgKE
Utility.sleep(500); !(_xu{(DL
breakWhile = true; 7 3z Y^x
9H}iX0O
A4Q)YY9~
for(int i=0;i<nStartPos.length;i++) K^vp(2
{ z){UuiUM+=
if(!fileSplitterFetch.bDownOver) !-RpRRR[Co
{ +R#`j r"
breakWhile = false; SfobzX}~Jh
break; 8*#][wC2
} ]az} n(B,
} 6>BDA?
if(breakWhile) kw^Dp[8X
break; @!a]qAt
D^s0EW-E
;]ShC\1
//count++; uP=_-ZUW
//if(count>4) e3={$Ah
// siteStop(); Z^`=!n-V
} g} ~<!VpX
3:8nwt
:iQ^1S`pH
System.err.println("文件下载结束！"); fI d)
} mYjiiql~
catch(Exception e){e.printStackTrace ();} iRwW>a3/
} 9h38`*Im;
:IT U0%;!+
d)GkXll1D
//获得文件长度 @oqi@&L'C
public long getFileSize() VtzmY
{ !+45=d 5
int nFileLength = -1; Go+xL/f
try{ F}B/-".^
URL url = new URL(siteInfoBean.getSSiteURL()); ~R?dDL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9Oo*8wvGG
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Jbc'V'fm
9MtJo.A
/IJ9_To
int responseCode=httpConnection.getResponseCode(); 88np/jvC{
if(responseCode>=400) <#p|z`N
{ -KwL9J4u
processErrorCode(responseCode); dI ZTLb"a
return -2; //-2 represent access is error %QsSR'`
} c7l!G~yx'
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>_0 i=.\
String sHeader; Q"6hD?6.
e7bT%h9i
qgC-@I
for(int i=1;;i++) v_ nBh,2
{ `\|3 ~_v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _/]:=_bf_z
//Utility.log(in.readLine()); G\:psx/
sHeader=httpConnection.getHeaderFieldKey(i); t1:S!@
if(sHeader!=null) 8/>wgY
{ 3^A/`8R7K
if(sHeader.equals("Content-Length")) ,F?~'-K
{ 28Ssb|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b?2X>QJ
break; ;+ Co!L
} ^0-e,d 9h
} 3dxnh,]&@
else yrE,,N%I
break; F'UguC">
} Z}K.^\S9
} [zh4W*K_cq
catch(IOException e){e.printStackTrace ();} cJHABdK-
catch(Exception e){e.printStackTrace ();} <(bCz>o|
PK2Rj%
@O<@f8-
Utility.log(nFileLength); UE&C
o! 2n}C
l)i&ATvCE
return nFileLength; Q/3tg
} *_{l
p(H)WD
"BLv4s|y7L
//保存下载信息（文件指针位置） ||'i\X|[
private void write_nPos() N[a ljC-R
{ \=EY@*=
try{ [DotS\p!z
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rg8m4xw
output.writeInt(nStartPos.length); s}[A4`EWH
for(int i=0;i<nStartPos.length;i++) 38w.sceaT
{ C)J_lI{^
// output.writeLong(nPos); (?!(0Ywbg
output.writeLong(fileSplitterFetch.nStartPos); qlz9&w
output.writeLong(fileSplitterFetch.nEndPos); ;e~{TkD
} Ere?d~8
output.close(); o8};e
} <uBhi4
catch(IOException e){e.printStackTrace ();} #Cg}!38
catch(Exception e){e.printStackTrace ();} +#-kIaU
} q:2aPfo&
*;OJ~zT
[xZ/ZWb/
//读取保存的下载信息（文件指针位置） C-a*EG
private void read_nPos() aDN6MZM
{ 2,8/Cb
try{ *l>[`U+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;T5,T
int nCount = input.readInt(); b"R, p=M
nStartPos = new long[nCount]; 5#TrCPi6A
nEndPos = new long[nCount]; ,c,Xd
for(int i=0;i<nStartPos.length;i++) RV0>-@/x
{ -~vl+L
nStartPos = input.readLong(); RjR&D?dc
nEndPos = input.readLong(); C@TN5?Z
} {[M0y*^64$
input.close(); o~OwE7H)A
} z`emKFbv
catch(IOException e){e.printStackTrace ();} >%uAQiU
catch(Exception e){e.printStackTrace ();} :rz9M@7
} p4m^ ~e
1a($8>
,2 zt.aqB
private void processErrorCode(int nErrorCode) <&qpl0U)Y
{ laUu"cS
System.err.println("Error Code : " + nErrorCode); 3bbp>7V!
} &Q-[;
H Z;ZjC*
/~o7Q$)-b
//停止文件下载 `y8 ?=
public void siteStop() ~")hE%Kl}
{ (R4PD
bStop = true; sBP}n.#$
for(int i=0;i<nStartPos.length;i++) 5cyddlaat
fileSplitterFetch.splitterStop(); o}9M`[
2Ueq6IuQ
!Y ;H(.A/
} T[5gom
} P &;y] ,)E
//负责部分文件的抓取 Od0S2hHO
**FileSplitterFetch.java _u:>1]
*/ Qqd6.F
package NetFox; pP|,7c5
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/6+1{p
import java.io.*; !cq=)xR
import java.net.*; "C_T]%'Wm
!GlnQ`T
5x*5|8
public class FileSplitterFetch extends Thread { f,Sth7y
nc3sty1`
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String sURL; //File URL ;j>*;Q`
long nStartPos; //File Snippet Start Position 0lX)Cl
long nEndPos; //File Snippet End Position mgi,b2
int nThreadID; //Thread's ID %v5)s(Yu
boolean bDownOver = false; //Downing is over lhLnygUk
boolean bStop = false; //Stop identical *)MX%`Z}
FileAccessI fileAccessI = null; //File Access interface C>*5=p|T
N=OS\pz
)>(L{y|uYX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gKmX^A5<
{ GE%2/z p
this.sURL = sURL; |0tg:\.
this.nStartPos = nStart; ./5jx2V
this.nEndPos = nEnd; 7m@ )Lv
nThreadID = id; Ihdu1]~R{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V -q%r
} E|pk.
VLf g[*k
Q Oz9\,C
public void run() r8IX/ ,
{ oS~}TR:}
while(nStartPos < nEndPos && !bStop) }X=87ud
{ w+q?T
\.c]kG>k-
M6J/mOVx5
try{ _Ny8j~
URL url = new URL(sURL); =kd YN5R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,5/V@;i
httpConnection.setRequestProperty("User-Agent","NetFox"); sC% b~
String sProperty = "bytes="+nStartPos+"-"; -@rxiC:Q
httpConnection.setRequestProperty("RANGE",sProperty); ?Q@L-H`
Utility.log(sProperty); `'uUmyg
D,MyI#
Ej' 7h~=v
InputStream input = httpConnection.getInputStream(); Z`rK\Bc
//logResponseHead(httpConnection); >4,{6<|
%PzQ\c
vKU`C?,L
byte[] b = new byte[1024]; yc*<:(p
int nRead; >B0D/:R9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |Dg;(i?
{ , Hn7(^t
nStartPos += fileAccessI.write(b,0,nRead); VJ3hC[
//if(nThreadID == 1) bFSlf5*H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pFpZbU^
} (Up'$J}
#e*X0;m
Ejq=*UOP
Utility.log("Thread " + nThreadID + " is over!"); ]$3+[9x'
bDownOver = true; mV<i JZh
//nPos = fileAccessI.write (b,0,nRead); 8)sg_JC
} 2A*/C7
catch(Exception e){e.printStackTrace ();} G-arnu)
} !(Q l)C
} nB=0T`vQ
Y[Es
~uB'3`x
//打印回应的头信息 DR6]-j!FK
public void logResponseHead(HttpURLConnection con) )%s +?
{ B#]_8svO
for(int i=1;;i++) tVunh3-
{ cqEHYJ;B
String header=con.getHeaderFieldKey(i); Xem 05%,
if(header!=null) wy''tqg6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `K w7"
Utility.log(header+" : "+con.getHeaderField(header)); Y~az!8j;Z
else Id%_{),HX
break; }&1Iyb
} *wwhZe4V
} yLW/ -%I#u
27>a#vCT
va5FxF*%
public void splitterStop() =N_,l'U\^
{ 9RxO7K
bStop = true; "IG+V:{ou
} k^^:;OR
uArR\k(
2/@D7>F&g
} >\ZR*CS
k5@d! }#c
8a9RML}G<
/* 8Y#bN*!
**FileAccess.java %w7m\nw@
*//文件访问(定位，写) ZW*n /#GUC
package NetFox; \X& C4#
import java.io.*; u?kD)5Nk
!qA8Zky_
azo0{`S?
public class FileAccessI implements Serializable{ < A?<N?%o
snYr9O[E6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6 mO"
RandomAccessFile oSavedFile; |) Pi6Y
long nPos; t8&q9$
Jf)3< ~G
:tM?%=Q
public FileAccessI() throws IOException b{RqwV5P
{ fYBH)E
this("",0); H] k'?;
} jJ~Y]dQi
zE`R,:VI
0+EN@Y^dAV
public FileAccessI(String sName,long nPos) throws IOException Uki9/QiX>
{ 5lTD]d
oSavedFile = new RandomAccessFile(sName,"rw"); Q.k :\m*h
this.nPos = nPos; /s c.C
oSavedFile.seek(nPos); ]>Si0%
} i[150g?K
&aPl`"j
%jEY3q
public synchronized int write(byte[] b,int nStart,int nLen) <tbZj=*O/o
{ i"HgvBHx
int n = -1; 9cd8=][
try{ K)S;:MLG=
oSavedFile.write(b,nStart,nLen); 5j eO"jB
n = nLen; rGlRAn#?,
} 5j{Np,K
catch(IOException e) r7 VXeoX
{ ug*D52?
e.printStackTrace (); s /%:dnij
} n|i"S`
:EZQ'3X
++8_fgM
return n; lJ{V
} 1$ML#5+,
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} #U=;T]!'$
\t3qS eWc/
4:mCXP,x
/* |NrrTN?>
**SiteInfoBean.java 0xpx(T[
*/ }B q^3?,#{
package NetFox; 47UO*oLS
T&xt`|
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public class SiteInfoBean { *8)2iv4[
W f@t4(i
ALGgAX3t
private String sSiteURL; //Site's URL <L2emL_'
private String sFilePath; //Saved File's Path {8@\Ij
private String sFileName; //Saved File's Name N[Sb#w`[/
private int nSplitter; //Count of Splited Downloading File _3>djF_u
O8|*M "
4tXSYHd3
public SiteInfoBean() 1;&;5
{//nSplitter的缺省值为5 =Q(vni83<
//default value of nSplitter is 5 DjHp+TyT
this("","","",5); 8)xt(~qF
} ~rv})4h
$/_qE
0^~\COa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .Q>!B?)
{ VC-;S7k
sSiteURL= sURL; (j&A",^^S
sFilePath = sPath; Veji^-0E
sFileName = sName; rt4Z;
this.nSplitter = nSpiltter; O~@fXMthh
g4&jo_3:p
xh0xSqDM
} T_#, A0G
-<N&0F4|*
K`k'}(vj
public String getSSiteURL() /_\W+^fE
{ 4MW ]EQ-
return sSiteURL; uQeu4$k!
} fgF;&(b
Ec]|p6a3
o6}n8U}bk
public void setSSiteURL(String value) *'ZN:5%H
{ x5Zrz<Y$w
sSiteURL = value; hu5!ev2
} #^rU x.
2KI!af[I
]hTb@.
public String getSFilePath() l@~LV}BI
{ RL}KAGK
return sFilePath; YQ(Po!NI\'
} 2t1I3yA'{z
`/Y+1 aD
Lz4ehWntO
public void setSFilePath(String value) Bw<rp-
{ Z1,gtl ?
sFilePath = value; Hs0pW5oZ
} >q7 %UK]&
&ak6zM
gPEqjj
public String getSFileName() y,m2(V
{ H{fM%*w
return sFileName; WDx Mo`zT
} ?Zcj}e.r
\pY^^ l*
-50AX1h31:
public void setSFileName(String value) ;Zut@z4\
{ `M@Ak2gcR+
sFileName = value; Y2T$BJJ
} kA#vByf`v
6*XM7'n
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public int getNSplitter() hW2.8f$
{ &M"ouy Zo9
return nSplitter; wH6u5*$p
} \2X$C#8E
F 3RB
s& yk
public void setNSplitter(int nCount) =mt?Cn}
{ Utt>H@t[
nSplitter = nCount; E{Vo'!LY
} n9hm790x-
} ;b%{ilx:
A7-r<s
<94G
/* *\XH+/]+
**Utility.java RtV.d\
*/ 8^yJqAXK
package NetFox; .y4&rF$n
?nFO:N<
"mIgs9l$
public class Utility { BBL485`
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ffcLuXa
public Utility() @}LZ! y
{ RA/EpD:H
ps1@d[n
sH!O0WL
} lZ+!H=`
')#,X^
//线程睡眠 TZB+lj1
public static void sleep(int nSecond) x8[MP?Wz
{ =dH$2W)G
try{ HFtf
Thread.sleep(nSecond); 1]OSWCEm*[
} UuJjO^t
catch(Exception e) *^XbDg9
{ (GU9p>2
e.printStackTrace (); lAASV{s{
} 4tc:.
} )ly ^Ox
g`,AaWlF
//日志 ;Ss$2V'a
public static void log(String sMsg) y{=NP
{ d#_m.j
System.err.println(sMsg); /g.]RY+u|x
} Tj/GClD:%
;!u;!F!i
Kn}ub+ "J
public static void log(int sMsg) dbF M,"^
{ :Ml7G
System.err.println(sMsg); l?E|RKp
} mP}#Ccji?
} Np,2j KF(
=,/D/v$m'2
xAdq+$><
/* d>i13dAI
**TestMethod.java Z`_.x &Y
*/ h'5Cp(G
package NetFox; %FA@)?~
Fvl`2W94;
h%}(h2W
public class TestMethod { <[Oo*:A!7
< K%j
]|Zb\{
public TestMethod() 9O98Q6-s
{ ///xx/weblogic60b2_win.exe <@#PF$!
try{ 2C "=!'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M<`|CVl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d,F5:w&
SiteFileFetch fileFetch = new SiteFileFetch(bean); #@//7Bf%
fileFetch.start(); ~L?nq@DL
} XW~bu2%{7"
catch(Exception e){e.printStackTrace ();} aW;aA'!
!{%G0(Dv
665[
} Q< *8<Oo4g
?p^2Z6J'$
8tc*.H{^+
public static void main(String[] args) %'ZN`XftG
{ < oI8-f
new TestMethod(); AXW!]=?X
} :)c80`-E
} ]7/gJ>g,
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