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)); 9t+:L(*pK
} gr\vC
for(int i=0;i<nEndPos.length-1;i++) O2S{*D={
{ 91|~KR)
nEndPos = nStartPos[i+1]; C]M{
} sWFw[Y>
nEndPos[nEndPos.length-1] = nFileLength; qJK-HF:#
} 17[vq!x6
} 4%*`'o$_
, %A2wV
+?^lnoX
//启动子线程 ;"]?&ri
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <4Ik]Uz^
for(int i=0;i<nStartPos.length;i++) _Kg"l5?B
{ fKNDl\SD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /vAA]n8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uO4R5F|tL
nStartPos,nEndPos,i); xbsX-F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NT<}-^
fileSplitterFetch.start(); Oee>d<
} iCdq-r/r!6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `! _mIh}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y|L]#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [-h=L Jf#
nEndPos = " + nFileLength); # N'_~:H
// fileSplitterFetch[nPos.length-1].start(); 3$PGLM
seA=7c5E
"tz`@3,5dN
//等待子线程结束 YQaL)t$0
//int count = 0; c:,K{ZR
//是否结束while循环 ,S-zY\XB
boolean breakWhile = false; NLZUAtx(
#.|MV}6rQ
~i=5NUE
while(!bStop) j,v2(e5:
{ 0b+End#mp
write_nPos(); -XWlmw*i(g
Utility.sleep(500); XT\Q"=FD
breakWhile = true; M~-jPY,+
0]2@T=*kTY
5 0<
for(int i=0;i<nStartPos.length;i++) uEdeA'*^
{ ::!{f+Up
if(!fileSplitterFetch.bDownOver) @^^,VgW[
{ 'Ug-64f>
breakWhile = false; X;3gKiD
break; D]hwG0Chd
} HKYJgx
} dPyZzMes=
if(breakWhile) YHI@Cj
break; 8&++S> <
Cm[^+.=I
crRYgr
//count++; j/w*2+&v
//if(count>4) jfsbvak
// siteStop(); xkmqf7w
} )r6d3-p1
H(ds
Y1L7sH 9
System.err.println("文件下载结束！"); THz=_L6
} K5:>
catch(Exception e){e.printStackTrace ();} 8aa`0X/6
} /PgcW
k{.`=j
"oo j;
//获得文件长度 Ap9 %5:]
public long getFileSize() lwp(Pq
{ xQ@gh ( (
int nFileLength = -1; E~eSHJ(oR7
try{ d/&~IR
URL url = new URL(siteInfoBean.getSSiteURL()); jt4c*0z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V"Y-|R
httpConnection.setRequestProperty("User-Agent","NetFox"); /|aD,JVN"
46M?Gfd,X
KPB^>,T2{
int responseCode=httpConnection.getResponseCode(); E~'QC
if(responseCode>=400) {igVuZ(>en
{ 9xIz[`)i.
processErrorCode(responseCode); l]KxUkA+
return -2; //-2 represent access is error (}&O)3)
} 6@cT;=W;xj
O`Ge|4
0ZjinWkR[
String sHeader; _Sn7z?
%TA@-tK=
^V;2v? O
for(int i=1;;i++) 5_= HtM[v]
{ 3ew`e"s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9ld'SB:#
//Utility.log(in.readLine()); &kNJs{
sHeader=httpConnection.getHeaderFieldKey(i); "[p-Iy1
if(sHeader!=null) w} 1~
{ 8@- UvT&o
if(sHeader.equals("Content-Length")) = ,^eQZR:
{ CiTjRJ-ZW)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2'5%EQW;0y
break; t&L+]I'P3
} :;u?TFCRx
} D+xHTQNTL
else C6cEt5
break; 6;vfl*
} |*-&x:p7O
} C lekB
catch(IOException e){e.printStackTrace ();} Fi_JF;
catch(Exception e){e.printStackTrace ();} euc|G Xs
95^A !
N)N\iad^
Utility.log(nFileLength); Aq:1
MW$ X4<*KD
^E349c-|
return nFileLength; f hS4Gb_
} 1Xj>kE:
R@Kzdeo
vS_Ji<W~E
//保存下载信息（文件指针位置） ae`6hW2
private void write_nPos() \OX;ZVb?5
{ -VVJf5/
try{ )S2GPn7
output = new DataOutputStream(new FileOutputStream(tmpFile)); .PJCBTe
output.writeInt(nStartPos.length); 9et%Hn.K'
for(int i=0;i<nStartPos.length;i++) z),@YJU"z
{ !HPye@Ua
// output.writeLong(nPos); ]E!b&
output.writeLong(fileSplitterFetch.nStartPos); >;}q
output.writeLong(fileSplitterFetch.nEndPos); !<2%N3l
} L?slIGp%-
output.close(); ROc)LCA
} MmPLJ
catch(IOException e){e.printStackTrace ();} 27q=~R}
catch(Exception e){e.printStackTrace ();} ueD_<KjE=
} 5h6c W
u~y0H
o@!Uds0
//读取保存的下载信息（文件指针位置） OELh6R
private void read_nPos() \Q m1+tg
{ E+$%88
try{ ltH?Ew<]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "g=g' W#
int nCount = input.readInt(); o,yP9~8\
nStartPos = new long[nCount]; ZN `D!e6
nEndPos = new long[nCount]; pX~X{JTaL)
for(int i=0;i<nStartPos.length;i++) 6mAaFDI,R
{ 8M&q
nStartPos = input.readLong(); v62M8r,Y
nEndPos = input.readLong(); { *&Wc Os
} eNEMyv5{w4
input.close(); !:<(p
} U.,_zEbx,
catch(IOException e){e.printStackTrace ();} ta'{S=^j
catch(Exception e){e.printStackTrace ();} -mur`tC
} ?wpS
:,'yHVG\
4ZAnq{nR4
private void processErrorCode(int nErrorCode) >q!:*
{ .Fe_Z)i>h
System.err.println("Error Code : " + nErrorCode); #D2.RN
} $pLJtQ
4u.Fy<+@4M
9\J.AAk~/
//停止文件下载 6*uWRjt
public void siteStop() aR0'$*3E
{ lcqpwSk
bStop = true; )GC9%mF;
for(int i=0;i<nStartPos.length;i++) Uxl7O4J@H
fileSplitterFetch.splitterStop(); {`>;I
zlhHSyK
W8><
} nA)KRCi
} XJI ff$K
//负责部分文件的抓取 Fk*C8
**FileSplitterFetch.java u4QBD5T"
*/ (l]_0-Z
package NetFox; 6Ex16
76BA1x+G
Mr6q7
import java.io.*; (S)jV0
import java.net.*; ]qPrXuS/
oT}-i [=}
MLk%U 4
public class FileSplitterFetch extends Thread { T}r}uw`
["7]EW\!:
nSR<(-j!
String sURL; //File URL @||GMA+|
long nStartPos; //File Snippet Start Position r0L' mf$
long nEndPos; //File Snippet End Position L+N;mI8
int nThreadID; //Thread's ID e]k\dj;,^%
boolean bDownOver = false; //Downing is over 3@8Zy:[8<
boolean bStop = false; //Stop identical YU6D;
FileAccessI fileAccessI = null; //File Access interface X6G2$|
'v0(ki#
R>y/Y<5=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ihBIE
{ %shCqS
this.sURL = sURL; v!6IH
this.nStartPos = nStart; ?AYb@&%
this.nEndPos = nEnd; &\L\n}i-
nThreadID = id; ~fY\;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6)[gF1
} {vox x&UX
YlJ_$Q[
++Fv )KY@
public void run() DW>|'w%
{ !~fy".|x
while(nStartPos < nEndPos && !bStop) JL!:`#\
{ PsO>&Te2
f(E[jwy
EWK?vs
try{ v%E~sX&CG
URL url = new URL(sURL); V(P 1{g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P]<15l
httpConnection.setRequestProperty("User-Agent","NetFox"); X1FKcWv
String sProperty = "bytes="+nStartPos+"-"; z6uHe{|
httpConnection.setRequestProperty("RANGE",sProperty); *yqke<o9)
Utility.log(sProperty); NEW0dF&)
-fT}Nj\
w" ,ab j
InputStream input = httpConnection.getInputStream(); 1HBWOV7z.?
//logResponseHead(httpConnection); DSL3+%KF#
SdNxSD$Q
~'VVCtA
byte[] b = new byte[1024]; {ug*
int nRead; 8c5=Px2\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wj 15Og?
{ j5MUP&/g3
nStartPos += fileAccessI.write(b,0,nRead); Ls/*&u
//if(nThreadID == 1) ",P?jgs^g5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GxS!Lk
} K8{ef
DA^!aJ6iF
#4!6pMW(&7
Utility.log("Thread " + nThreadID + " is over!"); IO?6F@(
bDownOver = true; 5fK<DkB$>:
//nPos = fileAccessI.write (b,0,nRead); zuvP\Y=V`
} PSa"u5O
catch(Exception e){e.printStackTrace ();} %$F\o1S
} sUsIu,1Q
} V_pKe~
Zy >W2(<
a4N8zDS
//打印回应的头信息 =eG:Scoug?
public void logResponseHead(HttpURLConnection con) el,n5OZ7
{ eXMl3Lxf
for(int i=1;;i++) C-ipxL"r
{ HO;,Ya^l
String header=con.getHeaderFieldKey(i); #NWc<Dd
if(header!=null) K|-RAjE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6Q9S~YYq
Utility.log(header+" : "+con.getHeaderField(header)); tNCKL.yU
else O)G^VD s
break; U`ELd:
} n\H.NL)
} sTO9>~sj
5[$jrG\!
cGe-|>:
public void splitterStop() >"+bL6#
{ pc<A ,?
bStop = true; 6w^Fee`>]
} h-[FUPfuw
N^K@$bs4^
}K\m.+%=d
} W=T,hOyh<W
&sJ%ur+G
5R7DD5c[
/* *Ldno`1O
**FileAccess.java 4 g^oy^~
*//文件访问(定位，写) G=%SMl>[
package NetFox; &c1zEgl
import java.io.*; | WMq&-$D
QAh6!<.;@
h ?%]uFJC
public class FileAccessI implements Serializable{ lVQy {`Ns
RP4P"m(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 seo.1.Da2
RandomAccessFile oSavedFile; 2DTBL:?`
long nPos; \@HsMV2+zN
7cJh^M
LdM9k(
public FileAccessI() throws IOException s0x;<si_
{ !*l5%H
this("",0); Qcf5*]V
} W{v-(pW
)mw&e}jRV
41V}6+$g
public FileAccessI(String sName,long nPos) throws IOException G(1y_t
{ D27MT/=7
oSavedFile = new RandomAccessFile(sName,"rw"); 'u{DFMB-A
this.nPos = nPos; _YgvLz %
oSavedFile.seek(nPos); 2E":6:Wsw
} =^LX,!2zp{
tX#8G09G+
<..|:0Q&~
public synchronized int write(byte[] b,int nStart,int nLen) lP:ll])p2
{ .;xt{kK
int n = -1; g$jZpU
try{ D~s TQfWr
oSavedFile.write(b,nStart,nLen); q|+`ihut
n = nLen; (\M&Q-xZ
} D,H v(6({
catch(IOException e) .\X;VWTI
{ fudIUG.
e.printStackTrace (); l6lyRJ
} a5AD$bP
.oNs8._:
M[@=m[#a
return n; "me a*-XB
} 3 O)^Hq+9
+w]KK6
![,W?
} U- a+LS
@m=xCg.Z
`bdCom
/* >;A7mi/
**SiteInfoBean.java 0Lo)Ni^"
*/ C&QT-|
package NetFox; 18AKM
Oa'DVfw2J
kq SpZoV0'
public class SiteInfoBean { FesXY856E
x]Nk T
JAK+v
private String sSiteURL; //Site's URL 5Cp6$V|/kv
private String sFilePath; //Saved File's Path ,y+}0q-Ou
private String sFileName; //Saved File's Name POtj6 ?a
private int nSplitter; //Count of Splited Downloading File vncak
:|\{mo1NB
6tPgFa#N
public SiteInfoBean() E26zw9d
{//nSplitter的缺省值为5 avb'J^}f
//default value of nSplitter is 5 5VU 5kiCt
this("","","",5); OUd&fUmH
} bk-veJR
)e$}sw{t
@nuMl5C-`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]}wo$7pO
{ `n*e8T
sSiteURL= sURL; f8T6(cA
sFilePath = sPath; H+oQ L(i|_
sFileName = sName; vbo:,]T<A
this.nSplitter = nSpiltter; {!lC$SlJ
_NfdJ=[Xh
k_E Jg;(
} GI~JIXHTQ
4pin\ZS:C
Rd?8LLz
public String getSSiteURL() g69^D
{ -A?6)ggf.
return sSiteURL; d-zNvbU"
} Z#O )0ou
1%v!8$
>tmv3_<=
public void setSSiteURL(String value) Ej\Me
{ AG3iKk??T
sSiteURL = value; w)#Lu/
} 78=a^gRB
_(U|Kpi
!CBvFl/v
public String getSFilePath() U?bQBHIC
{ Ix-bJE6+I,
return sFilePath; 7s2 l3
} t",=]k
FZt a
Jv,*rQH
public void setSFilePath(String value) > a"4aYj
{ 6,j&u7
sFilePath = value; oV,lEXz
} 6eq`/~#
k`;&??
-$@4e|e%a
public String getSFileName() ;{S7bH'6m
{ S/H!a:_5r
return sFileName; {q^?Rw
} n}!D)Gx
@$] CC1Y
O$$$1VHYo
public void setSFileName(String value) 8iKupaaOX
{ ganXO5T$
sFileName = value; ~ s# !\Ye
} 6S6E 1~
01AzM)U3"m
w?Nx^)xX
public int getNSplitter() xjO((JC
{ y+K21(z.
return nSplitter; +t`QHvxv
} eHQ3K#M#
,.PW qfb
}5{#f`Ca6
public void setNSplitter(int nCount) "F8A:tR
{ J2P5<
nSplitter = nCount; 1h0cId8d
} u>I;Cir4
} m(c5g[6nO
B}A7Usm
wD'LX
/* "J(7fL$!
**Utility.java 1> wt
*/ 4RU/y+[o
package NetFox; H;nq4;^yK
qGgqAF#B
ecgGl,{
public class Utility { 2gC.Z:}
=|G l
h=Xr J
public Utility() <D!\"C
{ 3kl\W[`?
d,0Yi u.p
g,seqh%
} =W Q_5}
kb>/R/,9
//线程睡眠 h0)Wy>B=,
public static void sleep(int nSecond) _'lrI23I
{ _a3,Zuv
try{ _Xn[G>1
Thread.sleep(nSecond); nS}XY
} c>*RQ4vE
catch(Exception e) i C nWb
{ t6)wR
e.printStackTrace (); ZxRD+`
} [|\JIr=of5
} Jm+hDZrW
}FTyRHD|
//日志 2@ <x%T
public static void log(String sMsg) ~X/1%
{ !PzlrH)M=p
System.err.println(sMsg); fi2@`37PM
} Rj|8lK;,
jI8qiZ);~
1o;+.]B
public static void log(int sMsg) :(|;J<R%_
{ ,\|W,N}~
System.err.println(sMsg); [kyF|3k~
} /Wh} ;YTv^
} ueiXY|
XZv(B^
\wxS~T<&L
/* wPn#>\/L
**TestMethod.java 0wLu*K5$4E
*/ n0T\dc~
package NetFox; (o1*7_]e
D-/K'|b
4*4s{twG
public class TestMethod { ?Mg&e/^
[lqwzW{(UN
wjF/c
public TestMethod() $#g1Mx{
{ ///xx/weblogic60b2_win.exe S=>54!{`x
try{ x?:[:Hf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /#z5bo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ISI\<qx
SiteFileFetch fileFetch = new SiteFileFetch(bean); "r!O9X6
fileFetch.start(); 0Ii* "?s
} Ji_3*(
catch(Exception e){e.printStackTrace ();} 92F(Sl
7u!i)<pn
Wc4F'}s
} r^mP'#
0*MY4r|-
kzqW&`xn?
public static void main(String[] args) :?s~,G_*l
{ G};os+FxF
new TestMethod(); JzJS?ZF
} >(s)S[\
} nc#}-}`5
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