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)); 8nNRn[oS
} bz,C%HFA
for(int i=0;i<nEndPos.length-1;i++) !}<Y^="
{ `O*+%/(
nEndPos = nStartPos[i+1]; D/{hLp{
} G9d@vu
nEndPos[nEndPos.length-1] = nFileLength; E7ixl~
} >/GVlXA'
} { "=d7i
!@5B:n*
EE-jU<>|
//启动子线程 fmFh.m.+N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6/ F]ncwG
for(int i=0;i<nStartPos.length;i++) r;SA1n#
{ d'q,:="c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qauk,t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), # sm>;+J
nStartPos,nEndPos,i); QF Vy2 q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >}Fe9Y.o
fileSplitterFetch.start(); X)x$h{ OE
} xV}-[W5sr'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6o!+E@V b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m&cVda/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "1yXOy^2
nEndPos = " + nFileLength); Fn1|Wt*
// fileSplitterFetch[nPos.length-1].start(); n}}$-xl
rISg`-
a}EO7tcg,
//等待子线程结束 1UT&kD!si
//int count = 0; :OQx;>'
//是否结束while循环 1ti+ Q0~
boolean breakWhile = false; ]+Ik/+Nz
Z2!O)8
wgp{P>oBX
while(!bStop) %9C_p]P*
{ .Xqe]cax%
write_nPos(); z^'3f!:3
Utility.sleep(500); :*k
breakWhile = true; ?@!dc6
]Vuq)#
ha&2V=
for(int i=0;i<nStartPos.length;i++) @Ge\odfF:
{ /p}^Tpu
if(!fileSplitterFetch.bDownOver) kzcl
{ Z]jm.'@z@
breakWhile = false; U8m/L^zh
break; W^v3pH-y#
} \("|X>00
} C5"=%v[gQv
if(breakWhile) HN?NY
break; ^`?2g[AA
!#xk?LyB
)!+~q!A
//count++; j]~;|V5Z
//if(count>4) ]rY:C "#
// siteStop(); \jH^OXxb
} AXFQd@#
.EpcMXT%
^}8qPBz
System.err.println("文件下载结束！"); \W:~;GMeD
} _!2bZ:emG
catch(Exception e){e.printStackTrace ();} XA PqRJ*Z
} mhpaPin*JS
Vz[tgb]-
X+dLk(jI`u
//获得文件长度 G6@XRib3
public long getFileSize() )i|0Ubn[|
{ J$"3w,O6+U
int nFileLength = -1; l/ufu[x!a
try{ 0&wbGbg(W
URL url = new URL(siteInfoBean.getSSiteURL()); )"KKBil0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p(vmMWR!
httpConnection.setRequestProperty("User-Agent","NetFox"); qJN!L))
Ps<;DE\$f4
^V,?n@c!
int responseCode=httpConnection.getResponseCode(); JiH^N!
if(responseCode>=400) p^J=*jm)x
{ ~*NG~Kn"s
processErrorCode(responseCode); #s%_ L
return -2; //-2 represent access is error IqD;*
} ePLpGT
.0 }eg$d
}Y9= 3X
String sHeader; ' m^nKG$"
9eR4?^(3!
*,az`U
for(int i=1;;i++) b5!D('w>]
{ T%q@jv{c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {/ef`MxV }
//Utility.log(in.readLine()); we?# Dui
sHeader=httpConnection.getHeaderFieldKey(i); ,v\^efc:%
if(sHeader!=null) |f67aN
{ 1xBgb/+
if(sHeader.equals("Content-Length")) GoSdo
{ 7H=V|Btnc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9:9gam
break; p#;I4d G
} :}0>IPW-V
} ; ,9:1.L
else XSOSy2:
break; \k 9EimT}
} +V Oczl=
} rvEX;8TS
catch(IOException e){e.printStackTrace ();} j{&*]QTN
catch(Exception e){e.printStackTrace ();} [[FDt[ l4
r&rip^40
?cur}`
Utility.log(nFileLength); !a9`]c
kD*r@s]=
.30eO_msK
return nFileLength; @y1:=["b
} N1!O8"Q|*3
\Dlmrke
X^o0t^
//保存下载信息（文件指针位置） 1Y+g^Z;G
private void write_nPos() z*,J0)<Q
{ A r,fmq
try{ 'LX]/D
output = new DataOutputStream(new FileOutputStream(tmpFile)); b%wm-p
output.writeInt(nStartPos.length); +Z7:(o<
for(int i=0;i<nStartPos.length;i++) \0fS;Q^{j
{ 15J t @{<r
// output.writeLong(nPos); }ebu@)r
output.writeLong(fileSplitterFetch.nStartPos); OrPi ("/
output.writeLong(fileSplitterFetch.nEndPos); BWF>;*Xro
} !FA[ ]d4
output.close(); u;G-46
} 2QIx~Er
catch(IOException e){e.printStackTrace ();} Qo\+FkhYq
catch(Exception e){e.printStackTrace ();} 1[:tiTG|C
} rK~Obv
Q'~3Ik
[6cF#_)*
//读取保存的下载信息（文件指针位置） +?9. &<?
private void read_nPos() 7MZ(tOR
{ as^!c!
try{ IRG-H!FV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A<p6]#t#X)
int nCount = input.readInt(); qxbGUyH==
nStartPos = new long[nCount]; 5}Z_A?gy
nEndPos = new long[nCount]; 6<SX%Bc~
for(int i=0;i<nStartPos.length;i++) Eg+z(m$M
{ sI<PYi={-6
nStartPos = input.readLong(); q=x1:^rVH
nEndPos = input.readLong(); ^~`t q+
} RLNto5?
input.close(); Vw";< <0HZ
} p>h&SD?b
catch(IOException e){e.printStackTrace ();} Lj2Au_5
catch(Exception e){e.printStackTrace ();} ~5:-;ZbZ
} HDHC9E6
Ihy76_OZ
~0V,B1a
private void processErrorCode(int nErrorCode) ,Pj UlcO_
{ I?OnEw
System.err.println("Error Code : " + nErrorCode); 2fFGS.l
} (@i2a
ZTzh[2u*
VMl)_M:'
//停止文件下载 6~+/cY-V
public void siteStop() 0eFvcH:qG
{ I><sK-3
bStop = true; Qm@v}pD
for(int i=0;i<nStartPos.length;i++) FA$1&Fu3Y
fileSplitterFetch.splitterStop(); (5h+b_eB
W.m2`] &
(W'3Zv'f
} l<-0@(x)
} ov|/=bzro
//负责部分文件的抓取 ~{$5JIpCm
**FileSplitterFetch.java 2p;N|V
*/ cyXnZs ?|
package NetFox; OM (D@up
snvixbN
|PutTcjQ
import java.io.*; ><w=
import java.net.*; cz;gz4d8
T:0#se
F.$NYr/|y
public class FileSplitterFetch extends Thread { cr>"LAi
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&O\$=&, h
String sURL; //File URL JW9U&Bj{
long nStartPos; //File Snippet Start Position h e1=
long nEndPos; //File Snippet End Position \(;X3h
int nThreadID; //Thread's ID 8/T,.<5
boolean bDownOver = false; //Downing is over l'FNp
boolean bStop = false; //Stop identical ^"{txd?6
FileAccessI fileAccessI = null; //File Access interface j-(k`w\
:d}@Z}2sD
;t5e]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |m>{< :
{ 0u=FlQ }h
this.sURL = sURL; k|;[)gE
this.nStartPos = nStart; uoMDf{d
this.nEndPos = nEnd; [`U9
nThreadID = id; ;S}_/'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f[+N=vr
} Zd<8c^@
IgNL1KRD
@ $2xiE.[
public void run() aP`V
{ q%hxU.h
while(nStartPos < nEndPos && !bStop) !_pryNcb
{ IiB"F<&[j{
+^<-;/FZue
Av,E|C
try{ UlH;0P?
URL url = new URL(sURL); +&qj`hA-b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o 4cqLMu
httpConnection.setRequestProperty("User-Agent","NetFox"); >Ni<itze$i
String sProperty = "bytes="+nStartPos+"-"; &vV_,$
httpConnection.setRequestProperty("RANGE",sProperty); "2>_eZ#b
Utility.log(sProperty); MB!$s_~o#L
<,huajQs
zOT(>1'
InputStream input = httpConnection.getInputStream(); ,_!MI+o0
//logResponseHead(httpConnection); 3-U@==:T
.TKKjS%8
`%Jq^uW
byte[] b = new byte[1024]; +?y9EZB%
int nRead; yGX"1Fb?;x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =N<Z@'c
{ rF)[ Sed:T
nStartPos += fileAccessI.write(b,0,nRead); 'G8.)eTA'
//if(nThreadID == 1) [.LbX`K:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B^lm'/,@
} (C60HbL
eG\`SKx_
9xM7X?
Utility.log("Thread " + nThreadID + " is over!"); ctT6va
bDownOver = true; pHv~^L%=
//nPos = fileAccessI.write (b,0,nRead); N3?@CM^hHw
} '/~j!H4q9
catch(Exception e){e.printStackTrace ();} m\;@~o'k
} vj4n=F,Z
} Qv/Kbw N{
,-.a! a
';Ew-u
//打印回应的头信息 \iM
public void logResponseHead(HttpURLConnection con) Ai5|N
{ +9[s(E?SY
for(int i=1;;i++) +"F9yb
{ JVt(!%K}&
String header=con.getHeaderFieldKey(i); nWb0S
if(header!=null) D/Hob
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |nq}#
Utility.log(header+" : "+con.getHeaderField(header)); q}MPl2
else ]}HuK#
break; mrId`<L5l{
} 6ujePi <U
} #P5tTCM
T Z_](%
7FvtWE*
public void splitterStop() ar[*!:!
{ ]q<Zc>OC
bStop = true; tZqy \_G
} fLR\@f
iz5WWn^
f]37Xl%I
} C">w3#M%
a[A9(Ftn
EH~XN9b
/* -9> oB
**FileAccess.java 8}<4f|?
*//文件访问(定位，写) Y!nxHRE
package NetFox; ! C|VX,w
import java.io.*; |Y|gT*v
Qz9*o
<{kr5<
public class FileAccessI implements Serializable{ &(t/4)IZox
4Y:[YlfD.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D0HLU ~o
RandomAccessFile oSavedFile; P8=!/L2?
long nPos; l4smAT
M73d^z
x9s1AzM{
public FileAccessI() throws IOException YMfjTt@Q
{ \g<=n&S?
this("",0); W*/0[|n*
} J8:f9a:|M
xIb^x=|h
zf}X%tp
public FileAccessI(String sName,long nPos) throws IOException >YuiCf?c7
{ ^oT!%"\
oSavedFile = new RandomAccessFile(sName,"rw"); o:8*WCiqrN
this.nPos = nPos; ZQ'bB5I
oSavedFile.seek(nPos); r~U/t~V=D
} Mz#<Vm4
+8~C&K:
4g}'/
public synchronized int write(byte[] b,int nStart,int nLen) dyNKok#
{ ?O.1HEr
int n = -1; k7\ ,No}
try{ @$ggPrs
oSavedFile.write(b,nStart,nLen); *oca
n = nLen; "Acc]CqH*
} 7GVI={b
catch(IOException e) Z[pMlg6Z
{ /Xo8 kC
e.printStackTrace (); N6wCCXd
} ]> 36{k]&
ic]b"ItD
0}d^UGD
return n; >Qg 9KGk'
} W]U},g8Z
@Wb_Sz4`
{ i2QLS
} L}x,>hbT
Fy8$'oc
#FQkwX'g
/* !.}ZlA
**SiteInfoBean.java S#wy+*
*/ kvo V?<!
package NetFox; F#^<t$5t
H@%Y"iIUP
{} gr\
public class SiteInfoBean { fu]mxGPc
t/`~(0F
H:jx_
private String sSiteURL; //Site's URL {ICW"Rlcs
private String sFilePath; //Saved File's Path a/v!W@Zz}
private String sFileName; //Saved File's Name X:1&Pdi
private int nSplitter; //Count of Splited Downloading File }aC@ov]2
j68_3zpl
7\xGMCctM
public SiteInfoBean() ~vMdIZ.h
{//nSplitter的缺省值为5 g!*5@k|C
//default value of nSplitter is 5 7Fd`MTo
this("","","",5); p,'Z{7HG
} n^P~]1i
y +2
.\6q\7Ej
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4`M7 3k0
{ *(>,\8OVf
sSiteURL= sURL; b)1v:X4Bv=
sFilePath = sPath; F\G-. 1
sFileName = sName; AZgeu$:7p<
this.nSplitter = nSpiltter; THl={,Rw`
1q7Y,whp
jqeR{yo&0b
} !i{9wI
KqI<#hUl
W3.(s~)o
public String getSSiteURL() VsJ4sb7
{ pdFa]
return sSiteURL; k(bDj[0q^
} psaPrE
;)'@kzi
:U!@
public void setSSiteURL(String value) B2/d%B
{ Q2(K+!Oe
sSiteURL = value; ^/V>^9CZ
} !`h^S)$
E@(nKe&6T_
Jdc{H/10
public String getSFilePath() gFQ\zOlY8a
{ .%x%b6EI
return sFilePath; :Ou[LF.O
} KyQd6 1
4J9VdEKk
)4tOTi[
public void setSFilePath(String value) Z,Z4Sp
{ >=+:lD
sFilePath = value; `k]2*$%
} cKM#0dq
nd4Z5=X
}gR!]Cs)^
public String getSFileName() 618k-
{ #q mv(VB4
return sFileName; rY,zZR+@
} ;rqW?':(i
9m+ejTK{U
km,I75o.
public void setSFileName(String value) !-cK@>.pE
{ y:Ne}S*ncE
sFileName = value; n)t'?7
} uK;&L?WB
-2/&i
]H$Trf:L
public int getNSplitter() V7}]39m(s
{ =73aME}
return nSplitter; h; "pAE
} Hq;*T3E
UrRYK-g
h7a/]~
public void setNSplitter(int nCount) w =2; QJ<
{ r>;(\_@
nSplitter = nCount; XEe$Wh
} # H)\ts
} -%)S~R
ya'Ma<4
B"Hz)-MW
/* qvC2BQ
**Utility.java #6F|}E
*/ &y&pjo6v1
package NetFox; h2P&<ggqX
o5;|14O
O/b1^ Y
public class Utility { {TVQ]G%'b
Memb`3
\f-@L;8#
public Utility() <Eu/f`8
{ JH+uBZh6
>v'@p
j^)=<+Q;=
} *bl|[(pP
u/.# zn@9h
//线程睡眠 +k{l]-)1
public static void sleep(int nSecond) Q79WGW
{ 8JojKH
try{ +|6E~#zklY
Thread.sleep(nSecond); }Dx5W9Ri"
} fJK;[*&Y
catch(Exception e) ;;}}uW=
{ cyH=LjgJf
e.printStackTrace (); "BA&
} %zYTTPLZ
} OIY
5h[<!f=
//日志 R q .2
public static void log(String sMsg) ,X)/ T!ff
{ E^C [G)7n
System.err.println(sMsg); `1i\8s&O6@
} ?`3G5at)9f
_+ERX[i
#}+_Hy
public static void log(int sMsg) ?.g="{5X
{ RV>n Op}R
System.err.println(sMsg); l(Y\@@t1
} ow4|GLU^;
} lFV\Go
Sd *7jW?
1B`JvNtd
/* ^%t{:\
**TestMethod.java p?' F$Wz
*/ Exz(t'
package NetFox; "P!zu(h4
xgJyG.?
p?#xd!tc2N
public class TestMethod { /xb37,
gJg%3K~,
I|tn7|*-A[
public TestMethod() S #C;"se
{ ///xx/weblogic60b2_win.exe 50^CILKo7
try{ A"wso[{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SN5Z@kK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0Ci:w|J
SiteFileFetch fileFetch = new SiteFileFetch(bean); =zRjb>
fileFetch.start(); f!bGH-.r5
} mMtva}=*
catch(Exception e){e.printStackTrace ();} Q(BM0n)f
$%zM Z
DcsQ6
} ',s{N9
6)1xjE#
.#_g.0<
public static void main(String[] args) uz@lz +
{ oR}'I
new TestMethod(); vFK!LeF%
} ]//Dd/L6
} oRHWb_$"
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