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)); 4,=;:#n,J
} tp"eXA0n
for(int i=0;i<nEndPos.length-1;i++) ! P$[$W
{ #*S.26P^4
nEndPos = nStartPos[i+1]; (BK_A{5
} ?5%o-hB|
nEndPos[nEndPos.length-1] = nFileLength; n-GoG(s..b
} Aeq^s
} qJ~fEX
7?vj+1;
@L 6)RF
//启动子线程 !@arPN$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tu;Pm4q7
for(int i=0;i<nStartPos.length;i++) <a+@4d;
{ B<G,{k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w)R5@ @C*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Zx: h)I
nStartPos,nEndPos,i); j(>xP*il
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZP0D)@8
fileSplitterFetch.start(); +KTHZpp!c2
} .jbxA2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CFoR!r:X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); alsD TQ'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \IqCC h
nEndPos = " + nFileLength); n7/&NiHxv/
// fileSplitterFetch[nPos.length-1].start(); nYBa+>3BDf
^nFP#J)_5
I;UT;/E2
//等待子线程结束 Q^xk]~G$(
//int count = 0; }Q6o#oZ
//是否结束while循环 v@J[qpX
boolean breakWhile = false; [e{W:7uFV
ZhC,nbM
oDt{;S8|]
while(!bStop) rz%^l1@-
{ BJg
write_nPos(); 8WKY 4nkj
Utility.sleep(500); /*M3Ns1@2
breakWhile = true; aej'cbO
wL>;_KdU`
<qI!Dj{
for(int i=0;i<nStartPos.length;i++) I;G(Wj
{ j^hLn>
if(!fileSplitterFetch.bDownOver) 0fqycGSmU
{ 'C>sYSL
breakWhile = false; V&Rwj_Y
break; {/,AMJ<:G]
} _~F 0i?
} =)w#?DGpj
if(breakWhile) wAL}c(EHO
break; a#9pN?~
p|BoEITL
%E [HMq<H
//count++; pEW~zl
//if(count>4) NQvI=R-g
// siteStop(); DhsvN&yNM
} )ac!@slb^7
+NiCt S
/fAAQ7
System.err.println("文件下载结束！"); K(WKx7Kky^
} O,NVhU7,
catch(Exception e){e.printStackTrace ();} 8f65;lyN
} 47f\
;=6EBP%
P^<to(|
//获得文件长度 D`KaIqLz
public long getFileSize() =4V SbOlZ
{ f=S2O_Ee
int nFileLength = -1; Imq-5To#
try{ T{yJL<
URL url = new URL(siteInfoBean.getSSiteURL()); VC%.u.< F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,]Xn9W
httpConnection.setRequestProperty("User-Agent","NetFox"); o-;/x)
+F2X2e)g"
|y+_BZ5
int responseCode=httpConnection.getResponseCode(); x]3[0K5;
if(responseCode>=400) ~-R2mAUK
{ K{B|
processErrorCode(responseCode); e,W,NnCICj
return -2; //-2 represent access is error rI6+St
} p(Osz7K
:AI%{EV-L
Mq'm TM
String sHeader; ,*?[Rg0]+
ooC9a>X
>vO+k^'Y
for(int i=1;;i++) JZ&_1~Z=
{ aeAx0yE[p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )8SWU)/
//Utility.log(in.readLine()); <$WS~tTz
sHeader=httpConnection.getHeaderFieldKey(i); dep"$pys>
if(sHeader!=null) j0(jXAc;UB
{ 5OX[)Li
if(sHeader.equals("Content-Length")) !+QfQghAT
{ k]`-Y E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nb6Y/`G
break; KeXt"U
} n1:q:qMR1
} tCar:p4$
else #3'M>SaoH
break; kQQDaZ8
} S2nX{=
} c& bms)Jwa
catch(IOException e){e.printStackTrace ();} 5}Xi`'g,
catch(Exception e){e.printStackTrace ();} ^Xu4N"@
;Zr7NKs
zgH*B*)bj
Utility.log(nFileLength); )?c,&
X>P|-n#
^5(d^N
return nFileLength; {t!7r_hj
} %/5Wj_|p
NK(_ &.F
M CP GDr
//保存下载信息（文件指针位置） n\f]?B(
private void write_nPos() ,CuWQ'H
{ qPN9Put
try{ )feZ&G]
output = new DataOutputStream(new FileOutputStream(tmpFile)); n=AcN
output.writeInt(nStartPos.length); Kpa$1x
for(int i=0;i<nStartPos.length;i++) D!.1R!(Z
{ a ~W
// output.writeLong(nPos); U%[ye0@:
output.writeLong(fileSplitterFetch.nStartPos); lBAu@M
output.writeLong(fileSplitterFetch.nEndPos); m]vV.pwv
} e?*Teb?R
output.close(); * 1xs/$`
} #.$y
catch(IOException e){e.printStackTrace ();} R^P>yk8
catch(Exception e){e.printStackTrace ();} RVLVY:h|F
} 4RYH^9;>K
@qj]`}Gx'
g|7o1{
//读取保存的下载信息（文件指针位置） cCNRv$IO\
private void read_nPos() !\9^|Ef?
{ P=\{
try{ P".IW.^kk~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4v3gpLH
int nCount = input.readInt(); ;ko6igx)+
nStartPos = new long[nCount]; )5gj0#|CG@
nEndPos = new long[nCount]; 7')W+`o8eL
for(int i=0;i<nStartPos.length;i++) ,]W|"NUI
{ G -+!h4p
nStartPos = input.readLong(); slUi)@b
nEndPos = input.readLong(); -B&(&R
} gZ7R^] k
input.close(); UxzF5V5
} 2Q5@2jT
catch(IOException e){e.printStackTrace ();} Hbd>sS
catch(Exception e){e.printStackTrace ();} w`V6vYd@
} .R'M'a#*!A
hqmE]hwc
X;Sb^c"j1
private void processErrorCode(int nErrorCode) Y:t?W
{ :zLf~W
System.err.println("Error Code : " + nErrorCode); T<?kH
} FO:L+&hr?>
^\?Rh(pu
s&-MJ05y
//停止文件下载 aekke//y
public void siteStop() *kg->J
{ ?+^p$'5
bStop = true; a.}#nSYP
for(int i=0;i<nStartPos.length;i++) {\P%J:s#9
fileSplitterFetch.splitterStop(); r~ 2*'zB
x3+{Y
^879sI
} >X'-J{4R
} $D#h, `
//负责部分文件的抓取 Ve&_NVPrd
**FileSplitterFetch.java k%i.B
*/ a%`%("g!
package NetFox; }$'_%,
E5M/XW\E6
!]82$
import java.io.*; |D"L!+J-$
import java.net.*; #?jsC)
)H{1Xjh-
tHZ"o!(S
public class FileSplitterFetch extends Thread { Zr2!}jD9a
(I#6!Yt9J
k_7b0dr%F
String sURL; //File URL 40h$- VYT/
long nStartPos; //File Snippet Start Position 80[# 6`
long nEndPos; //File Snippet End Position vk48&8
int nThreadID; //Thread's ID Kw"y#Ys]
boolean bDownOver = false; //Downing is over #X?[")R
boolean bStop = false; //Stop identical jYRSV7d
FileAccessI fileAccessI = null; //File Access interface nW7: ]
bS r"k
j9hfW'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =2Yt[8';
{ YZ4`b-
this.sURL = sURL; KGg S"d
this.nStartPos = nStart; ]0ErT9
this.nEndPos = nEnd; #?>)5C\Hqy
nThreadID = id; ]Z8u0YtM)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4^l9d
} 4oiE@y&{4
`cXLa=B)9
>RkaFcq
public void run() 8X"4RyNSn
{ cOX)+53
while(nStartPos < nEndPos && !bStop) wTU$jd1;+
{ w|s2f`!
]B=*p0~j^n
T:X*
try{ O& Sk}^
URL url = new URL(sURL); $jE<n/8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EOXkMr
httpConnection.setRequestProperty("User-Agent","NetFox"); <KU0K
String sProperty = "bytes="+nStartPos+"-"; hQm=9gS
httpConnection.setRequestProperty("RANGE",sProperty); 0't)-Pj+,
Utility.log(sProperty); =CK%Zo
Jcze.t
M?"4{
InputStream input = httpConnection.getInputStream(); f/UU{vX(
//logResponseHead(httpConnection); nLz;L r!
WX?nq'nr
8^y=YUT
byte[] b = new byte[1024]; s_IFl5D]
int nRead; %"A8Af**I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >,]a>V
{ ~^Cx->l
nStartPos += fileAccessI.write(b,0,nRead); r*vh3.Agl
//if(nThreadID == 1) PKrG6% W+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O@a OKk
} ~Dq-q6-@t
q| 1%G Nb
Q!@M/@-Ky
Utility.log("Thread " + nThreadID + " is over!"); E2>{seZ
bDownOver = true; K9%rr_ja!
//nPos = fileAccessI.write (b,0,nRead); 04Zdg:[3-!
} rCDt9o>
catch(Exception e){e.printStackTrace ();} ]?@ [Ny=0
} \#: W
} *eIX"&ba
8p%0d`sX
K $- *
//打印回应的头信息 81{8F
public void logResponseHead(HttpURLConnection con) 49=pB,H;H
{ }={@_g#
for(int i=1;;i++) 8fP2qj0
{ 5S!#^>_
String header=con.getHeaderFieldKey(i); 6)uBUM;i
if(header!=null) 5tbCx!tL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +a.2\Qt2A
Utility.log(header+" : "+con.getHeaderField(header)); 2{b/*w
else K-TsSW$}
break; -@(LN%7!C
} u'l4=e
} ojnO69v
&@oI/i&0B
]j>xQm\
public void splitterStop() uK" T~
{ $\J5l$tU
bStop = true; %akW43cE
} GuR^L@+ -.
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Gkuqe3
} e7;7TrB.
:KO&j"[
j;`Q82V\
/* #Pg`0xiV
**FileAccess.java !VWA4 e!+
*//文件访问(定位，写) I~n4}}9M
package NetFox; .J O3#
import java.io.*; gdf0
EO)JMV?6
<jV,VKL#
public class FileAccessI implements Serializable{ P".}Y[GD
vK)'3%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zo&i0%S\E
RandomAccessFile oSavedFile; i-v: %
long nPos; n<8WjrK
=|E "
&wK:R,~x6
public FileAccessI() throws IOException {UP[iw$~
{ r 1r@TG\
this("",0); h^=;\ng1l
} Ak@!F6~
zJw5+ +
pmB {b
public FileAccessI(String sName,long nPos) throws IOException aO<7a 6
{ hc q&`Gun
oSavedFile = new RandomAccessFile(sName,"rw"); %oa@2qJ^
this.nPos = nPos; GO"|^W
oSavedFile.seek(nPos); bfz7t!A)A
} ~ q-Z-MA
C7{VByxJ
SDC|>e9i
public synchronized int write(byte[] b,int nStart,int nLen) t7-]OY7%w_
{ jI\@<6O
int n = -1; V>QyiB
try{ >b2!&dm
oSavedFile.write(b,nStart,nLen); ASbIc"S6
n = nLen; DW7E ]o
} doL-G?8B
catch(IOException e) Zu|NF uFI
{ J;_4 3eS
e.printStackTrace (); AA=Ob$2$
} iRrUIWx
vGv<WEE
]4H)GWHKg
return n; _|M8xI
} \o[][R#D
c_vGr55
nDraX_sm=
} jyIIE7.I"
`(HD'fud3
9Q,>I6`l
/* } KyoMs
**SiteInfoBean.java ?]D&D:Z?I
*/ <CuUwv 'A
package NetFox; iUcX\ uW
~4~r
0`S{>G
public class SiteInfoBean { *MmH{!=
=OO4C
}lp37,
private String sSiteURL; //Site's URL Uwkxc
private String sFilePath; //Saved File's Path l3Zi]`@r
private String sFileName; //Saved File's Name MBt\"b#t
private int nSplitter; //Count of Splited Downloading File ir}z^+
-O$vJ,*
%mmV#vwp
public SiteInfoBean() zF`a:dD$d
{//nSplitter的缺省值为5 oH=?1~e
//default value of nSplitter is 5 sA?8i:]O:
this("","","",5); "e"#k}z9
} C1NU6iV^z
%l!A%fn(
BmV`<Q,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8 *f9
{ 5.VPK 338A
sSiteURL= sURL; eaf-_#qb
sFilePath = sPath; ]#G s6CsT|
sFileName = sName; eAW)|=2
this.nSplitter = nSpiltter; :^kAFLU
5 I_ :7$8
7k*
} a^l)vh{+
p[P#!
f>6{tI5X
public String getSSiteURL() SWzqCF
{ n}a`|Nbk
return sSiteURL; A4f"v)vM
} @Pcgm"H<
m"~ddqSMT
crv#IC2
public void setSSiteURL(String value) .;7V]B1o
{ TXi|
sSiteURL = value; :7LA/j
} 8/>.g.]
EY"of[p
;7s^slVzF
public String getSFilePath() #,z-Pj?O!
{ &V*MNi,4Z
return sFilePath; mQ`atFz:Z
} wY ItG"+6
T9$~tv,5F
R*bx&..<
public void setSFilePath(String value) sPQjB[
{ [z!m
sFilePath = value; r2#G|/=@
} lUjZ=3"'
_<f%== I'
[4#HuO@h
public String getSFileName() >;9g`d
{ q`p0ul,n
return sFileName; )]q Qgc&
} ?rOj?J9
`WH$rx!
n`Z}tQ%)o
public void setSFileName(String value) (!fx5&F
{ \Ebh6SRp\
sFileName = value; b|AjB:G
} wzy[sB274
J#C4A]A
@}6<,;|DQ
public int getNSplitter() ?n{m2.H
{ +/celp
return nSplitter; WwsNAJ
} 1f+A_k/@
,X3D<wl
3A^AEO
public void setNSplitter(int nCount) kkZ}&OXS;
{ L@O>;zp;
nSplitter = nCount; +PE-j| D
} _5S0A0
} VB905%
* ;sz/.
6rbR0dSgx
/* %pjY^tM/
**Utility.java @,oc%m
*/ 3q`f|r
package NetFox; MD$W;rk(Hn
mRAt5a#is
sT1k]duT
public class Utility { ;R0LJApey
B ZU@W%E
+)yoQRekX
public Utility() [nHN@p|
{ v\bWQs1
axmq/8X
l4T[x|')M
} `#iL'ND[
`=pA;R9
//线程睡眠 j.6!T'$|
public static void sleep(int nSecond) L *\[;.mk
{ 8Kl&_-l{b
try{ F^{31iU~CX
Thread.sleep(nSecond); K?,?.!ev
} EG^ rh;
catch(Exception e) #f(tzPD
{ nW]CA~
e.printStackTrace (); 8Ys)qx>7'
} tt-ci,X+
} "Ai\NC
$yU}56(z~
//日志 &;?+ ^L>
public static void log(String sMsg) tH; 6Mp;f
{ %`pi*/(
System.err.println(sMsg); ^! h3#4
} o% Q7 el$f
+pSo(e(
!otseI!!/
public static void log(int sMsg) >a*dI_XE
{ M*n94L=Sg&
System.err.println(sMsg); ;\}dQsX
} }>AA[ba"'
} VTR4uT-
v(0ujfSR0
au19Q*r9
/* G[ns^
**TestMethod.java c/.s`hz
*/ =#4>c8MM
package NetFox; %x,HQNRDU
1O,5bi>t7
4E=QO!pVv
public class TestMethod { ZYY~A_C
2V;{@k
%w>3Fwj`z
public TestMethod() E4\HI+
{ ///xx/weblogic60b2_win.exe 7)}_'p
try{ j*gZvbO;'L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oR`rs[Kj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^& *;]S`
SiteFileFetch fileFetch = new SiteFileFetch(bean); *GYLj[
fileFetch.start(); "D>/#cY1/
} S=kO9"RB]
catch(Exception e){e.printStackTrace ();} dm"x?[2:
f uU"
l#]#_
} xc-[gt6
Qt\:A!'jw
9a@S^B>
public static void main(String[] args) P//nYPyzg
{ \2~\c#-k
new TestMethod(); I+W,%)vb
} yz,_\{}
} '`gnJX JO
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