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)); XdIno}pN
} \I i#R
for(int i=0;i<nEndPos.length-1;i++) $#e}9g.
{ (421$w,B%
nEndPos = nStartPos[i+1]; M6cybEk`
} n5xG4.#G
nEndPos[nEndPos.length-1] = nFileLength; anz7ae&P'K
} `::j\3B&Y-
} pvt/{
#q34>}O< O
Z{(Gib~{N
//启动子线程 ~7}no}7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sR PQr?
for(int i=0;i<nStartPos.length;i++) _d~GY,WTdO
{ |:(BI5&S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k(>J?\iNW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PNLlJlYlP
nStartPos,nEndPos,i); 24InwR|^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OdyL j
fileSplitterFetch.start(); A|IPQ=
} jyg>'"W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gHUW1E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >@4Ds"Ye"O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 056yhB
nEndPos = " + nFileLength); n$j B"1
// fileSplitterFetch[nPos.length-1].start(); >Gg[J=7`
aAoAjVNkK
1:cq\Y
//等待子线程结束 Y uZ
//int count = 0; S WsD]rn
//是否结束while循环 gDfM}2]/
boolean breakWhile = false; 3H"F~_H
p(4Ek"
G@ybx[_[@
while(!bStop) +A,cdi9z
{ z&GGa`T"
write_nPos(); PK?}hz
Utility.sleep(500); D0f7I:i1
breakWhile = true; S#+ _HFUK{
K24y;968
35-FD{
for(int i=0;i<nStartPos.length;i++) *Z"Kvj;>u
{ ZMyd+C_P2
if(!fileSplitterFetch.bDownOver) aM[fag$c
{ H-5f!>)
breakWhile = false; Rx%kAt2X
break; &#q%#M:
} ~|KMxY(:
} <N80MUL|
if(breakWhile) g5Hsz,x
break; 0\$Lnwp_
:]C\DUBo
"J >, Hr9
//count++; &:+_{nc,
//if(count>4) 84Hm PPt
// siteStop(); WFeaX7\b
} #@5 jOi
CA"`7<,
4f0dc\$
System.err.println("文件下载结束！"); GEb)nHQq
} WWTJ%Rd|
catch(Exception e){e.printStackTrace ();} yNx"Ey dk`
} 1^;&?E
<* PjG}Z.
xi\uLu?i
//获得文件长度 [qt^gy)
public long getFileSize() v#sx9$K T
{ 1 gRR
int nFileLength = -1; .fW`/BXE
try{ zgpPu4t
URL url = new URL(siteInfoBean.getSSiteURL()); VKrKA71Z~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]}0+7Q
httpConnection.setRequestProperty("User-Agent","NetFox"); / dn]`Ge)
R91u6r#
3^&pb
int responseCode=httpConnection.getResponseCode(); ]@1ncn7N
if(responseCode>=400) RzSN,bLR
{ 0$nJd_gW_
processErrorCode(responseCode); U`'w{~"D%
return -2; //-2 represent access is error :(x 90;DW
} !C0= h
b}q,cm
WUi7~Ei}
String sHeader; U(qM( E
UuA=qWC
]7"mt2Q=3
for(int i=1;;i++) X]CaWxM
{ gzdgnF2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8|Y^z_C
//Utility.log(in.readLine()); 8i"{GGVC
sHeader=httpConnection.getHeaderFieldKey(i); {gi"ktgk
if(sHeader!=null) *XzUqK
{ u09OnP\
if(sHeader.equals("Content-Length")) ~JT{!wcE}o
{ eS Fmx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;6)|'3.B9
break; CnA*o 8w
} Kd,m;S\
} XJOo.Y
else anV)$PT=
break; !8s:3]
} khu,P[3>
} !p9F'7;Y<
catch(IOException e){e.printStackTrace ();} @fYA{-ZC
catch(Exception e){e.printStackTrace ();} gf@'d.W}
? 8!N{NV
->#7_W
Utility.log(nFileLength); @o^sp|k !
AU$5"kBE
%I=J8$B]f
return nFileLength; 42Ffx?Qmv
} {5z?5i ?D
9hp0wi@W}
,!py n<_
//保存下载信息（文件指针位置） =O_[9kuJ
private void write_nPos() da^9Fb
{ ta4<d)nB
try{ /iQ>he~fy
output = new DataOutputStream(new FileOutputStream(tmpFile)); yq,5M1vR
output.writeInt(nStartPos.length); @+!d@`w:z2
for(int i=0;i<nStartPos.length;i++) EX5kF
{ D 7E^;W)H
// output.writeLong(nPos); QY fS-
output.writeLong(fileSplitterFetch.nStartPos); !c`1~a!
output.writeLong(fileSplitterFetch.nEndPos); ]V]o%onW
} XF$C)id2p
output.close(); bU,&|K/
} BPOWo8TqD^
catch(IOException e){e.printStackTrace ();} ) D`_V.,W
catch(Exception e){e.printStackTrace ();} BZ T%+s;u9
} &boBu^,94
q.X-2jjpx:
Zj^H3h
//读取保存的下载信息（文件指针位置） Ek.j@79
private void read_nPos() Z,&ywMm/G
{ 5LK>n-
try{ 4%{m7CK}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \%VoX`B
int nCount = input.readInt(); _0`O}
nStartPos = new long[nCount]; .lnD]Q
nEndPos = new long[nCount]; t2$:*PvE
for(int i=0;i<nStartPos.length;i++) 3G&1. 8
{ 8UZEC-K
nStartPos = input.readLong(); Te/)[I'Tn
nEndPos = input.readLong(); Y+7v~/K=
} Fy@D&j
input.close(); d$Xvax,C
} - |'wDf?H
catch(IOException e){e.printStackTrace ();} 1f:k:Y9i
catch(Exception e){e.printStackTrace ();} {gn[ &\
} jHZ<Gc
@'y"D
$7*Ml)H!9
private void processErrorCode(int nErrorCode) X[[=YCi0
{ m1hf[cg
System.err.println("Error Code : " + nErrorCode); mnia>; 0H
} J{ Vl2P?@
#75;%a8
Mf63 59
//停止文件下载 tpctz~ .
public void siteStop() *dl@)~i
{ ,O+7nByi[V
bStop = true; ] ge-b\
for(int i=0;i<nStartPos.length;i++) `F@yZ4L3S
fileSplitterFetch.splitterStop(); M/qiA.C@W
N@>S>U8C
EIfrZg7R
} o_5@R+&
} PTh Ya
//负责部分文件的抓取 s5dh]vNN
**FileSplitterFetch.java Lsz`nD5
*/ a`uT'g[*
package NetFox; \CGcP
x@ O:
$b$D[4
import java.io.*; }R x%&29&
import java.net.*; {%Y7]*D
4SrK]+|
^s*} 0
public class FileSplitterFetch extends Thread { )wRD
{1+H\(v
FRW.
String sURL; //File URL #wyS?FP-
long nStartPos; //File Snippet Start Position UTt#ltun?
long nEndPos; //File Snippet End Position Id0F2 [
int nThreadID; //Thread's ID ;a`X|N9
boolean bDownOver = false; //Downing is over ~83P09\T%
boolean bStop = false; //Stop identical 1DP)6{x
FileAccessI fileAccessI = null; //File Access interface yN.D(ZwF:
GdU W$.
,L;vN6~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;<A/e
{ 5dk,!Cjg
this.sURL = sURL; YovY0nO
this.nStartPos = nStart; v=>Gvl3&U
this.nEndPos = nEnd; URgF8?n
nThreadID = id; pS\>X_G3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AngwBZ@
} #`$7$Y~]
Xn=fLb(
K;l'IN"N
public void run() :S12=sFl$
{ ?+\,a+46P_
while(nStartPos < nEndPos && !bStop) \YS?}! 0
{ nz\fN?q
rWXW}Yg
|9I;`{@
try{ O)R0,OPb
URL url = new URL(sURL); F?kVW[h?q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @El<"\
httpConnection.setRequestProperty("User-Agent","NetFox"); *@nUas2"
String sProperty = "bytes="+nStartPos+"-"; ?s]`G'=>V`
httpConnection.setRequestProperty("RANGE",sProperty); `,Gk1~Wv
Utility.log(sProperty); [ UJj*n
)QD}R36Ic
`9l\~t(M
InputStream input = httpConnection.getInputStream(); $ Zr,-
//logResponseHead(httpConnection); ise}> A!t
@UJmbD{
z sPuLn9G
byte[] b = new byte[1024]; )|x5#b-lz
int nRead; lijy?:__
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cG:`Zj~4
{ d ] ;pG(
nStartPos += fileAccessI.write(b,0,nRead); $NHWg(/R@
//if(nThreadID == 1) pt#[.n#f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |5Pbc&mH8A
} kVv <tw
}q W aE
k;5}@3iQ
Utility.log("Thread " + nThreadID + " is over!"); r.;iO0[/
bDownOver = true; Rjl__90
//nPos = fileAccessI.write (b,0,nRead); :F=nb+HZ
} H)Ge#=;ckQ
catch(Exception e){e.printStackTrace ();} 8)8oR&(f
} sIsu >eL
} p%1m&/`F
[!mjUsut*
1.uQ(>n
//打印回应的头信息 su;S)yZb
public void logResponseHead(HttpURLConnection con) a7G2C oM8
{ di2=P)3
for(int i=1;;i++) Y;Gm,
{ YPnJldVn
String header=con.getHeaderFieldKey(i); u0b-JJ7)BQ
if(header!=null) 1,'^BgI,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -d'|X`^nE
Utility.log(header+" : "+con.getHeaderField(header)); GNc|)$
else ,0]28D
break; nn4Sy,cz
} I;H9<o5
} wf%Ep#^6}
A>A'dQ69
>r3< O=Z7
public void splitterStop() 5Suc#0y
{ ot#kU 8f
bStop = true; 79g>7<vp
} 0f/!|c
, % jTXb
oH0F9*+W
} 3G|fo4g
Y26l,XIV
`0|&T;7
/* L$Ar]O)
**FileAccess.java J6D$ i+
*//文件访问(定位，写) Ilb |:x"L
package NetFox; N06O.bji
import java.io.*; agT[y/gb
PM!t"[@&
TR_oI<xB2
public class FileAccessI implements Serializable{ C/XyDbH
_C=[bI@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >0#q!H,X
RandomAccessFile oSavedFile; d ovwB`5
long nPos; ^l&4UnLlc
ky$:C,1t
^)^|;C\`
public FileAccessI() throws IOException W r7e_
{ _kX/LR"L+
this("",0); %uqD\`-
} +\vY;!^
BV?N_/DXp
e7qMt[.
public FileAccessI(String sName,long nPos) throws IOException M;V#Gm
{ s^'#"`!v=
oSavedFile = new RandomAccessFile(sName,"rw"); M`pTT5r
this.nPos = nPos; 4~YQ\4h=
oSavedFile.seek(nPos); Prz+kPP
} :k(t/*Nl3
E/$@ud|l"
LE80`t>M#
public synchronized int write(byte[] b,int nStart,int nLen) *1S.9L
{ *Ne2l`!1m
int n = -1; }SN44 di(
try{ =M{CZm
oSavedFile.write(b,nStart,nLen); } %CbZ/7&
n = nLen; T-2p`b}hW
} o\;"|O}
catch(IOException e) N<"6=z@w+
{ {&u7kWD|
e.printStackTrace (); T^;Jz!e
} ss@}Dt^
He-Ja
UJ)M:~O
return n; O8~U<'=*
} JX$NEq(
(g2r\hI
NF(IF.8G
} XAxI?y[c
^O Xr: P
JKi@Kw
/* ;4v}0N~.
**SiteInfoBean.java P9mxY*K)%5
*/ "q>I?UcZ
package NetFox; EJ;0ypbG
$F`<&o
)bXx9,VL
public class SiteInfoBean { akc"}+-oX
r,@X>_}
2G}7R5``9
private String sSiteURL; //Site's URL 4[CBW
private String sFilePath; //Saved File's Path \g:qQ*.
private String sFileName; //Saved File's Name fy=C!N&/
private int nSplitter; //Count of Splited Downloading File p2c=;5|/Q
$N+{r=
hB$Y4~T%
public SiteInfoBean() m/c&/6nk
{//nSplitter的缺省值为5 9_A0:S9Z
//default value of nSplitter is 5 /xm#:+Sc
this("","","",5); :;*#Qh3"
} s.I1L?s1w?
lPcVhj6No%
5az 4NT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) . (*kgv@3x
{ H^PqYLjN
sSiteURL= sURL; _ kSPUP5
sFilePath = sPath; +V+*7s%fL
sFileName = sName; r~G]2*3
this.nSplitter = nSpiltter; h[ZN >T
A;WwS?fyQ
[T[9*6Kt
} 6:@t=C
e(;`9T
'UvS3]bSYW
public String getSSiteURL() @wdB%
{ qzlMn)e
return sSiteURL; zhX`~){N6
} HMS9y%zl/
:OQ:@Yk
$,QpSK`9i
public void setSSiteURL(String value) E4v_2Q -w
{ #u<oEDQ
sSiteURL = value; 51ajE2+X&
} U_}A{bFG
sAD P~xvU
K)Xs L
public String getSFilePath() W]yClx \
{ +/!=Ub[:U
return sFilePath; (&P0la1
} gR-Qj
[#>$k 6F*
ZP63Alt
public void setSFilePath(String value) u_6BHsU
{ IzGB
sFilePath = value; R<lNk<
} ]zvVY:v
+>!B(j\gx
-Nlf~X
public String getSFileName() Dd5xXs+c
{ }rY?=I
return sFileName; }$0xt'q&
} QLB1:O>
g<rKV+$6
inPdV9
public void setSFileName(String value) =(|xU?OL
{ C7jc6(>m
sFileName = value; JwI`"$>w
} ,na=~.0R:
N,/BudFo
L'\/)!cEd
public int getNSplitter() 8R)D! 7[l
{ 3m43nJ.~
return nSplitter; "'F;lzq
} 0Y6q$h>4
gP%|:"
znQ'm^h
public void setNSplitter(int nCount) `j}_BW_
{ _Vo)<--+I
nSplitter = nCount; 'Wf?elB+
} 1A?\BJ"
} 5U)ab3:
}#ep}h
#j^('K|
/* >9.5-5"
**Utility.java Wiq{wxe
*/ 0j{F^rph
package NetFox; joChML_
O/DAf|X|
mZbWRqP[|_
public class Utility { cZDxsd]
9RCO|J
%R.xS} Q
public Utility() @ kJ0K
{ w*<Y$hnBzF
GJIWG&C03
%_b^!FR
} Q$|^~
R,x>$n
//线程睡眠 GP[6nw_'^
public static void sleep(int nSecond) N;Z`%&
{ *?^Z)C>
try{ Sg.+`xww3
Thread.sleep(nSecond); }xkLD!
} C5PmLiOHY>
catch(Exception e) 4-7kS85
{ |RR%bQ^{
e.printStackTrace (); `%t$s,TiP
} A$%Q4jC}
} >Lw}KO`
UTDcX
//日志 5!'R'x5e
public static void log(String sMsg) HDF!`
{ E\]OySC%C$
System.err.println(sMsg); Y8)E]D
} p~Hvl3SxR
4AY _#f5u
*<*0".#
public static void log(int sMsg) NI5]Nz<?
{ -,~;qSs
System.err.println(sMsg); %s$rP
} w~kHQ%A
} ioC@n8_[G
~Na=+}.q_
a -xW8
/* "t[M'[ `C
**TestMethod.java On{~St'V
*/ !;o\5x<'$O
package NetFox; ]ZzoJ7lr
$?FS00p*|X
7$!`p,@we/
public class TestMethod { AIZW@Nq.5
"wA0 LH_
2[Z0I4r
public TestMethod() a'@-"qk
{ ///xx/weblogic60b2_win.exe $uEJn&n7}
try{ Z69+yOJI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t6'61*)|0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ! jbEm8bt
SiteFileFetch fileFetch = new SiteFileFetch(bean); _Kc1
fileFetch.start(); Dh2:2Rz=#7
} 2.[_t/T
catch(Exception e){e.printStackTrace ();} "| Kf'/r
\*f;!{P{
az0cS*@
} Vh"MKJ'R^
9o-!ecx}
28nmQ
public static void main(String[] args) Gs[Vu@*
{ <jbj/Q )"
new TestMethod(); Wgxn`6
} /Zo~1q
} P3'2IzNw
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