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)); KX~ uE6rX
} RL4|!HzR
for(int i=0;i<nEndPos.length-1;i++) Culv/
{ ra*|HcLD
nEndPos = nStartPos[i+1]; 6<W^T9}v@/
} .\oW@2,RA9
nEndPos[nEndPos.length-1] = nFileLength; HE+'fQ!R
} U>*@VOgB
} >bV3~m$a+
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v];YC6shx
//启动子线程 8i] S[$Fc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t`Bk2Cc)+
for(int i=0;i<nStartPos.length;i++) } 9zi5o8
{ wqDf\k}'v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VQ('ejv}/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3y.+03 W
nStartPos,nEndPos,i); c\ZI 5&4jT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3\Xk)a_
fileSplitterFetch.start(); ^Ak?2,xB#+
} _qPKdGoM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]zj#X\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7fypUQ:y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IrYj#,xJ
nEndPos = " + nFileLength); &I-:=ir
// fileSplitterFetch[nPos.length-1].start(); q0%QMut%
T^^7@\vDI
=M?+KbTJ3
//等待子线程结束 }R+#>P
//int count = 0; Z#u{th
//是否结束while循环 q'S[TFMNE
boolean breakWhile = false; $)*qoV
A v>v\ :.>
%G(VYCeK
while(!bStop) uSXnf
{ RDSC@3%
write_nPos(); EFDmNud`Q
Utility.sleep(500); [@qjy*5p
breakWhile = true; CP9Q|'oJ
u^SInanw
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for(int i=0;i<nStartPos.length;i++) W3/] 2"0
{ ]+,L/P
if(!fileSplitterFetch.bDownOver) U0-RG
{ . h)VR 5?j
breakWhile = false; mQVlE__ub
break; ,1 H|{<
} O+mEE>:w%
} / :.I&^>P
if(breakWhile) ;rL>{UhG
break; ?;Sg,.J
IY.M#Q]
J[l7p6xk
//count++; F/Js K&&
//if(count>4) &zgliT!If
// siteStop(); TXYO{
} j9c:SP5
q<.k:v&
U^[AW$WzU
System.err.println("文件下载结束！"); i;~.kgtq4
} :-59~8&
catch(Exception e){e.printStackTrace ();} W"s/8;
} nT:<_'!
p&\QkI=
l@w\ Vxr
//获得文件长度 ?r|iZKa
public long getFileSize() & +`g~6U
{ < `;Mf>V
int nFileLength = -1; [}Xw/@Uc;
try{ Wx#l}nD
URL url = new URL(siteInfoBean.getSSiteURL()); [H!do$[>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z~(X[Zl :
httpConnection.setRequestProperty("User-Agent","NetFox"); VG7#C@>Z
vt"bB
bO$KV"*!
int responseCode=httpConnection.getResponseCode(); xH28\]F5n
if(responseCode>=400) <J~6Q
{ Edc3YSg%;
processErrorCode(responseCode); 7?g({]
return -2; //-2 represent access is error IN6L2/Q
} eI`%J3BxR
(5`(H.(
A]QGaWK
String sHeader; ;XNC+mPK
KRm)|bgE
9qi|)!!L
for(int i=1;;i++) 07qjWo/t
{ |Z>}#R!,P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1:7fV@jw
//Utility.log(in.readLine()); PY4">~6\i
sHeader=httpConnection.getHeaderFieldKey(i); OPUrz?p2C
if(sHeader!=null) )X*_oH=
{ 1)}hzA
if(sHeader.equals("Content-Length")) G?~Yw'R^8
{ Q>X1 :Zn3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pdN8hJ
break; zO9WqP_`iR
} c<q33dZ!*
} |R91|-H
else !}mM"|<
break; &<&eKq
} ErA*a3
} 9;*B*S~znW
catch(IOException e){e.printStackTrace ();} DV?c%z`YO
catch(Exception e){e.printStackTrace ();} ae3 Gn}tf
LD WYFOGQ
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Utility.log(nFileLength); xzx~H>M
.j)DE}[q>
Ao\OU}
return nFileLength; 2b\h@VJt
} E2o8'.~Yd`
" 5Pqvi
ou)0tX3j
//保存下载信息（文件指针位置） "kc%d'c(
private void write_nPos() 0"\js:-$
{ ooa"Th<
try{ Ug#B( }/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6R3/"&P(/#
output.writeInt(nStartPos.length); Y*jkUQ
for(int i=0;i<nStartPos.length;i++) NP\/9 8|1
{ 4%yeEc;z
// output.writeLong(nPos); R Ee~\n+P^
output.writeLong(fileSplitterFetch.nStartPos); /55 3v;l<
output.writeLong(fileSplitterFetch.nEndPos); ;x|?N*
} |P9MhfN
output.close(); ;l `(1Q/
} !*qQ7
catch(IOException e){e.printStackTrace ();} .db:mSrL
catch(Exception e){e.printStackTrace ();} R4[|f0l}s
} #8vl2qWbi
-idbR[1{?
#="Lr4T
//读取保存的下载信息（文件指针位置） >Wd=+$!I
private void read_nPos() j}}as
{ oO &%&;[/A
try{ P|fh4b4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N-<,wUxf
int nCount = input.readInt(); ?6\A$?
nStartPos = new long[nCount]; 9,>c;7s X
nEndPos = new long[nCount]; (A_H[xP
for(int i=0;i<nStartPos.length;i++) .`D$.|!8g
{ 7O=7lQ
nStartPos = input.readLong(); v~dUH0P<>e
nEndPos = input.readLong(); F CfU=4O
} \@NnL\t u
input.close(); G&N),wsNZK
} HZ{DlH;&
catch(IOException e){e.printStackTrace ();} C91'dM
catch(Exception e){e.printStackTrace ();} R6o07.]
} {oo(HD;5
iqd7
IQ~EL';<w
private void processErrorCode(int nErrorCode) Hb$wawy<
{ J rYL8 1
System.err.println("Error Code : " + nErrorCode); )q{e L$
} v~!_DD au
6l|SGt\
Q^lgtb
//停止文件下载 cR6#$-a
public void siteStop() \S?;5LacZ
{ (iO/@iw
bStop = true; n5#9o},oK
for(int i=0;i<nStartPos.length;i++) m0Uk*~Gz
fileSplitterFetch.splitterStop(); ]>(pQD
2F,?}jJ.K
unN*L
} riglEA[^
} FePWr7Ze
//负责部分文件的抓取 RDqQ6(e"
**FileSplitterFetch.java Zq/=uB7Z
*/ `g}en%5b\
package NetFox; >6zWOYd
,f~8:LHq
~X) 1!Sr
import java.io.*; K;g6V!U
import java.net.*; w^ 8^0i-
nhq,Y0YH
eGrxS;NY
public class FileSplitterFetch extends Thread { pN;Tt+}
6bpO#&T
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String sURL; //File URL _cc9+o
long nStartPos; //File Snippet Start Position wqQrby<
long nEndPos; //File Snippet End Position >$A,B
int nThreadID; //Thread's ID VsRdZ4
boolean bDownOver = false; //Downing is over C #@5:$
boolean bStop = false; //Stop identical kqS_2[=]
FileAccessI fileAccessI = null; //File Access interface TGG-rA6@Lx
ueJ_F#y
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iS8yJRy
{ ?trqe/
this.sURL = sURL; W^9=z~-h
this.nStartPos = nStart; (=D^BXtH|
this.nEndPos = nEnd; kkV*#IZ
nThreadID = id; Z9I ?j1K|!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .|J-(J<>[.
} vau#?U".}>
8&y3oxA,
p@=B\A]
public void run() =/^{Pn
{ EK^["_*A
while(nStartPos < nEndPos && !bStop) u6p nO
{ N07FU\<9
p( [FZ
LsV?b*^(p
try{ A|0\ct
URL url = new URL(sURL); Ha!]*wg#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X;p4/ *U
httpConnection.setRequestProperty("User-Agent","NetFox"); 8:Jc2K
String sProperty = "bytes="+nStartPos+"-"; 'miY"L:| O
httpConnection.setRequestProperty("RANGE",sProperty); |Z{ DU(?[b
Utility.log(sProperty); _dw6 C2]P
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l*4_
InputStream input = httpConnection.getInputStream(); CEb al\R
//logResponseHead(httpConnection); 6%UhP;(
[yfi:|n1
qRA,-N
byte[] b = new byte[1024]; xcu:'7'K[
int nRead; ~f!iz~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R`emI7|
{ DWar3+u&0
nStartPos += fileAccessI.write(b,0,nRead); e^Lt{/
//if(nThreadID == 1) `n`aA)|<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )XL}u4X
} @D&}ZV=J
MF~Tr0tOC
]bb`6 \h
Utility.log("Thread " + nThreadID + " is over!"); 0RGSv!w
bDownOver = true; 7S]akcT/
//nPos = fileAccessI.write (b,0,nRead); ejPK-jxCa/
} "( P-VX
catch(Exception e){e.printStackTrace ();} D4CiB"g3*
} x4bj?=+
} 7<3eB)S
UZRCJ
5"&{Egc_
//打印回应的头信息 ;K<W<v5m0N
public void logResponseHead(HttpURLConnection con) N2S7=`5/T
{ IgU65p
for(int i=1;;i++) xs3t~o3y
{ ZzV%+n7<Vx
String header=con.getHeaderFieldKey(i); :f58JLX
if(header!=null) sa>}wz<o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ZA/:\6gm
Utility.log(header+" : "+con.getHeaderField(header)); xp"5L8:C
else N|L Ey
break; Hb{G RG70
} 4XL]~3 c
} MfNguh
"~zQN(sR"P
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public void splitterStop() #}{1>g{sXt
{ _3?7iH
bStop = true; V:8ph`1
} ZI'Mr:z4
A#B6]j)
~kAen
} \a6knd
MX{p)(HW
.V:H~
/* $x%VUms
**FileAccess.java VY=c_Gl
*//文件访问(定位，写) g<r'f"^
package NetFox; F(Iq8DV
import java.io.*; @`6db
nXuoRZ
;/phZ$l
public class FileAccessI implements Serializable{ H6PS7g"
&7\q1X&Rr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >B9|;,a
RandomAccessFile oSavedFile; :. ja~Q
long nPos; w;p!~o &
0au\X$)Q
cp7Rpqg
public FileAccessI() throws IOException 4uG:*0{Yx
{ Nn;p1n dN
this("",0); 'cx&:s
} g5*Zg_G/
zT5@wm
iB,Nqs3i*
public FileAccessI(String sName,long nPos) throws IOException -K K)}I`
{ 9e|]H+y
oSavedFile = new RandomAccessFile(sName,"rw"); ^"!j m
this.nPos = nPos; s*U~Q=Z
oSavedFile.seek(nPos); \D37l_
} \y G//
HFL(t]
}.UE<>OX
public synchronized int write(byte[] b,int nStart,int nLen) iX{Lc+u3
{ _DK%-,Spu
int n = -1; W6m oFn
try{ 3K57xJzK
oSavedFile.write(b,nStart,nLen); 'y?(s+
n = nLen; 'v"{frh
} G=lket6
catch(IOException e) i2EXE0;
{ xN +j]LC
e.printStackTrace (); hKtc
} ~#b&UR
u-a*fT
n^Qt !~
return n; T*%Q s&x;
} A:3:Cr
9aE!! (E
d|9B3I*I
} j'V# =vH
4ISZyO=
5Y\wXqlY
/* <XV\8Y+n
**SiteInfoBean.java d+Vx:`tT
*/ :{d?B$
package NetFox; nSL x1Q
4$=Dq$4z
'Zdjd]
public class SiteInfoBean { xi]qdiA
I3A@0'Vm;L
Rmrv@.dr!
private String sSiteURL; //Site's URL >!vb;a!
private String sFilePath; //Saved File's Path B!=JRfT
private String sFileName; //Saved File's Name u*ZRU 4U
private int nSplitter; //Count of Splited Downloading File fBptjt_
TqM(I[J7\
R~$W
public SiteInfoBean() fJ3*'(
{//nSplitter的缺省值为5 ?=%Q$|]-
//default value of nSplitter is 5 rH9wRY(
this("","","",5); '=_}&
} S?bG U8R5
tkFGGc}w\
do2~LmeW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N|v3a>;*l
{ n_Ht{2I
sSiteURL= sURL; /N`l z>^~
sFilePath = sPath; TS9=A1J#
sFileName = sName; i9.~cnk
this.nSplitter = nSpiltter; h]rF2 B
Gu-*@C:^&
0k?ph$
} QPf#y7_@u
W?a2P6mAh
rRN7HL+b
public String getSSiteURL() NM0[yh
{ KB$s7S"=
return sSiteURL; GT[,[l
} !H`Q^Xf}
BTXS+mvl
[/}y!;3iXM
public void setSSiteURL(String value) %E95R8SL
{ :GU6v4u
sSiteURL = value; edh?I1/
} Hz}6XS@
AHq;6cG
paUlp7x
public String getSFilePath() tdTD!'
{ *^XfEO
return sFilePath; "x.|'
} LLn,pI2fL{
$'I+] ;
E$-u:Z<-
public void setSFilePath(String value) !$"DD[~\
{ `.f {V
sFilePath = value; h*_h M1*;
} "5]Fl8c?
_`>F>aP
D}SYv})Ti
public String getSFileName() EK^B=)q6:W
{ ;- D1n
return sFileName; bwjjwu&
} 3@ a
JJHr<|K
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public void setSFileName(String value) yJx{6
{ ceakTAB[
sFileName = value; 5:mS~
} " h,<PF
)P:r;a'
VJ`c/EVIt
public int getNSplitter() z z@;UbD"
{ 1]HEwTT/1_
return nSplitter; FE+Y#
} 6&pI{
V6.xp{[
m_Owe/BC#m
public void setNSplitter(int nCount) IL?mt2IQ>
{ \#P>k;D
nSplitter = nCount; D(}w$hi8
} Y<U"}}
} ew(CfW2
~{,U%B
|wASeZMO2
/* MB9tnGO-Q
**Utility.java \atztC{-L>
*/ =yv_i]9AN
package NetFox; <MgR x9
2%YtMkC5
>uS?Nz5/
public class Utility { bi:m;R
{EKzPr/
cd36f26`"w
public Utility() 0h~Iua5
{ R;9H`L/>
hlPZTr=a
9Foo8e
} )D ^.{70N
XeD9RMT
//线程睡眠 ;[*jLi,uc
public static void sleep(int nSecond) @1#QbNp#
{ jseyT#2
try{ ! 6kLL
Thread.sleep(nSecond); y{hy
} +{V"a<D$m
catch(Exception e) V`OeJVe
{ ]I9Hbw
e.printStackTrace (); ~]HeoQK
} 6iwIEb
} yvxdl=s
x0^O?UR
//日志 AtRu)v6r
public static void log(String sMsg) ZCJOh8
{ 3.q%?S}*
System.err.println(sMsg); 1eC1Cyw
} uJz<:/rwZ-
O)ks
6"^Yn.
public static void log(int sMsg) wB6ILTu1
{ 2Yd0:$a
System.err.println(sMsg); t+'|&b][Qi
} c@RMy$RTF
} $x,?+N
i>!7/o
[6@{^
/* sY4sq5'!
**TestMethod.java %T]NM3|U
*/ 1O bxQ_x
package NetFox; Sa!r ,l
]3@6o*R;
pkjf5DWp
public class TestMethod { I@VhxJh
iB[>uW
tlw$/tMa
public TestMethod() > Y <in/
{ ///xx/weblogic60b2_win.exe yT Pi/=G
try{ QJc3@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !w['@x.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +0U{CmH
SiteFileFetch fileFetch = new SiteFileFetch(bean); <vx/pH)f
fileFetch.start(); rrK&XP&
} f,9jK9/$
catch(Exception e){e.printStackTrace ();} (~F{c0\C
O5HK2Xg,C
V5y8VT=I
} hC ^|
1iq,Gd-G.
<7HVkAa
public static void main(String[] args) J&4QI( b.
{ S pxkB!
new TestMethod(); c$),/0td|
} {6%vmMbJ
} ]>fAV(ix
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