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)); +FAj30
} s8)`wH?
for(int i=0;i<nEndPos.length-1;i++) UKQ"sC
{ 4(8trD6
nEndPos = nStartPos[i+1]; Z`u$#<ukX
} xP!QV~$>
nEndPos[nEndPos.length-1] = nFileLength; FF~r&h8H
} %4f.<gz~r|
} +D:8r|evH
-rn6ZSD)
'It8h$^j
//启动子线程 xhOoZ-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tM^4K r~o,
for(int i=0;i<nStartPos.length;i++) "L:4 7!8
{ <l$ d>,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X.#)CB0c1Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P6R_W
nStartPos,nEndPos,i); RFyMRE!?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y;uR@{
fileSplitterFetch.start(); z V\+za,
} t2s/zxt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 10i$b<O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o$buoGSPc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +l/v`=C
nEndPos = " + nFileLength); {BT/P!
// fileSplitterFetch[nPos.length-1].start(); 0=#>w_B
S.)Jp-&K
}&t>j[
//等待子线程结束 avL_>7q
//int count = 0; r]UF<*$
//是否结束while循环 V@!)Pw
boolean breakWhile = false; \1Xk[%
dniU{v
eM:J_>7t
while(!bStop) Iz5NA0[=2
{ _BmObXOp.
write_nPos(); #5Z`Q^
Utility.sleep(500); X 3$ W60Q
breakWhile = true; yjg&/6
6FQi=}O1
*Bq}.Yn
for(int i=0;i<nStartPos.length;i++) s:Ml\['x
{ 1XMR7liE
if(!fileSplitterFetch.bDownOver) 8&)v%TX
{ 1(Ta*"(0Ip
breakWhile = false; G$+v |z
break; $KO2+^%y
} uI)twry]@
} Z0jgUq`r
if(breakWhile) /}(d'@8p
break; +t+<?M B
:q]9F4im
^k;]"NR
//count++; fq]PKLW'
//if(count>4) RhH1nf2UR
// siteStop(); |zYOCDFf
} {K]5[bMT
{O^u^a\m
|4Q*4s
System.err.println("文件下载结束！"); 9)ALJd,M
} )ODF6Ag
catch(Exception e){e.printStackTrace ();} ]~KLdgru_
} Jpj=d@Of70
vRmn61
3KkfQ{
//获得文件长度 XiE`_%NW
public long getFileSize() pn gto
{ TZAd{EZa
int nFileLength = -1; G @..?>
try{ t?W}=%M[
URL url = new URL(siteInfoBean.getSSiteURL()); {`QHg O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X#lNS+&='
httpConnection.setRequestProperty("User-Agent","NetFox"); P5h|* ?=
.B# .
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int responseCode=httpConnection.getResponseCode(); DK)W ,z|
if(responseCode>=400) K^shTh8k
{ " B#|C'
processErrorCode(responseCode); Yf w>x[#e
return -2; //-2 represent access is error 50W+!'
} ["Ltqgx
5^u$zfR
`hi=y BO
String sHeader; <+i(CGw
vxOqo)yO
gBm'9|?
for(int i=1;;i++) _\ToA9m
{ sjr,)|#[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;uUFgDi
//Utility.log(in.readLine()); :8A+2ra&
sHeader=httpConnection.getHeaderFieldKey(i); Ey&H?OFiP
if(sHeader!=null) elOeXYO0
{ G%<}TI1}
if(sHeader.equals("Content-Length")) wA=r]BT
{ ,#A(I#wL~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $J`O-"M
break; h:YD$XE
} oJz2-PmX
} bbK};u
else @ _Ey"k<
break; r]DiB:.
} }TmOoi(X@
} FzT.9Vz7
catch(IOException e){e.printStackTrace ();} U(#<D7}
catch(Exception e){e.printStackTrace ();} {ez$kz
t4WB^dHYp
5p;AON
Utility.log(nFileLength); 'o>)E>
M"~jNe|
;b$P*dSG}
return nFileLength; 1i76u!{U
} _ E;T"SC
MtLWpi u@[
XO <wK
//保存下载信息（文件指针位置） Z*%;;&?
private void write_nPos() RP4/:sO
{ yB b%#GW
try{ /`*{57/3
output = new DataOutputStream(new FileOutputStream(tmpFile)); =}^NyLE?
output.writeInt(nStartPos.length); ,XD" p1(|G
for(int i=0;i<nStartPos.length;i++) Jl Do_}
{ > ;,S||
// output.writeLong(nPos); 9u B?-.
output.writeLong(fileSplitterFetch.nStartPos); :!`"GaTy
output.writeLong(fileSplitterFetch.nEndPos); Da=EAG-{7
} Mt[yY|Ec|
output.close(); QU"WpkO
} kRp]2^}\s\
catch(IOException e){e.printStackTrace ();} 22`^Rsb,6L
catch(Exception e){e.printStackTrace ();} k ut=(;
} ZZw`8 E
-Zt!H%U
{Su?*M2y
//读取保存的下载信息（文件指针位置） i"2OsGT
private void read_nPos() "TV'}HH
{ 4CNrIF@
try{ $*yYmF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *]6g-E?:@
int nCount = input.readInt(); D'" T'@
nStartPos = new long[nCount]; BuJo W@)
nEndPos = new long[nCount]; $ V^gFes
for(int i=0;i<nStartPos.length;i++) p@m0Oi,=
{ n ~t{]if"
nStartPos = input.readLong(); qpjY &3SI
nEndPos = input.readLong(); O\5%IfB'"
} /k#-OXP~
input.close(); #@XBHJD\#
} dGIdSQ~ _
catch(IOException e){e.printStackTrace ();} Rn1oD3w
catch(Exception e){e.printStackTrace ();} OxlA)$.hpu
} '%N?r,x C
Pf*6/7S:
N'Gq9A
private void processErrorCode(int nErrorCode) M&Uy42,MR
{ /x<g$!`X
System.err.println("Error Code : " + nErrorCode); [BWq9uE
} 54 lD+%E
*FS8]!Qg
`KJ(.m
//停止文件下载 a:kAo0@":j
public void siteStop() D31X {dJ
{ %()d$.F
bStop = true; %go2tv:|W
for(int i=0;i<nStartPos.length;i++) 7#V7D6j1
fileSplitterFetch.splitterStop(); @=-(H<0
P"YdB|I
eV;r /4
} _:x]'w%
} i_Kwxn$
//负责部分文件的抓取 i2F7O"f.
**FileSplitterFetch.java d t/AAk6
*/ o3J#hQrl
package NetFox; dbp\tWaW
:6n#y-9^1
E)"19l|}B
import java.io.*; peQwH
import java.net.*; ~#-?V[
&5CRXf
5ut| eD`3
public class FileSplitterFetch extends Thread { nL@'??I1
XJ18(Q|w'
=|t-0'RsN
String sURL; //File URL &?<uR)tl
long nStartPos; //File Snippet Start Position X Xque-
long nEndPos; //File Snippet End Position (lk9](;L
int nThreadID; //Thread's ID Z}W{ iD{
boolean bDownOver = false; //Downing is over --yF%tRMP
boolean bStop = false; //Stop identical ER0 Yl
FileAccessI fileAccessI = null; //File Access interface vygzL U^
' \JE>#
]#tB[G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !3Q0Ahf
{ ~#_~DqbMZ5
this.sURL = sURL; q+g,?;Yx
this.nStartPos = nStart; b--=GY))F
this.nEndPos = nEnd; F%OP,>zl
nThreadID = id; *ap,r&]#F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (q)}`1d'
} eYOY
1\}vU
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public void run() 5`;SI36"
{ !_QI<=X
while(nStartPos < nEndPos && !bStop) f|[7LIdh-
{ Sj+H{xJi
g4K+AK
iw@rW5%'~
try{ Q(|@&83].
URL url = new URL(sURL); A8{jEJ=)P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yD\q4G
httpConnection.setRequestProperty("User-Agent","NetFox"); 1w,_D.1'
String sProperty = "bytes="+nStartPos+"-"; +! 1_Mt6
httpConnection.setRequestProperty("RANGE",sProperty); K'A+V
Utility.log(sProperty); lriezI
|9*Rnm_
~7m`p3W@
InputStream input = httpConnection.getInputStream(); ?<?Ogq"<
//logResponseHead(httpConnection); XlppA3JON|
g~lv/.CnA+
?]Yic]$n
byte[] b = new byte[1024]; ot0teNF
int nRead; |t,sK aL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'gwh:
{ T:^.; ZY
nStartPos += fileAccessI.write(b,0,nRead); sh/,"b2!P
//if(nThreadID == 1) |G j.E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _@5Xmr
} _3/u#'m0
L+t / E`
]U?nYppV
Utility.log("Thread " + nThreadID + " is over!"); }$ y.qqG
bDownOver = true; *zrT;jG
//nPos = fileAccessI.write (b,0,nRead); m&)/>'W
} Dri6\/0
catch(Exception e){e.printStackTrace ();} u[a-9^&g
} Nr|Gw @+
} {^]qaQ[5N
UZdnsG7
hf`y_H+\7
//打印回应的头信息 x39tnf/F
public void logResponseHead(HttpURLConnection con) N,`@Q7
{ h ldZA
for(int i=1;;i++) xP8/1wd.
{ 0h-NT\m
String header=con.getHeaderFieldKey(i); gtKih
if(header!=null) D*l(p5[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fB2ILRc
Utility.log(header+" : "+con.getHeaderField(header)); ak7%
else \XDiw~0
break; \f,<\mJ#
} ?1Nz ,Lc$
} kQ\GVI11?
]TvMT
j.M]F/j
public void splitterStop() 757&bH|a
{ l)r\SE1
bStop = true; y-pdAkDh
} :zW? O#aL-
Z$z-Hx@%
[* xdILj
} 7F`\Gz_2
qlhc"}5x }
FPc`J
/* <IrhR,@M,L
**FileAccess.java Q%CrB>|@
*//文件访问(定位，写) Q Xd`P4a
package NetFox; (Mc{nFqS
import java.io.*; !t%1G.
fh#:j[R4e
\`.v8C>vG
public class FileAccessI implements Serializable{ :3F[!y3b
^EIuGz1@0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0fc;H}B*
RandomAccessFile oSavedFile; \Z.r Pq
long nPos; CvIuH=,
= MByD&o`
b+Q{Z*
public FileAccessI() throws IOException +2[0q% i
{ Wvb ~j
this("",0); /&6{}n
} [3dGHf;miw
@(R=4LL
g0f4>m
public FileAccessI(String sName,long nPos) throws IOException VEV?$R7;
{ 6AIqoX*p
oSavedFile = new RandomAccessFile(sName,"rw"); y[J9"k(@
this.nPos = nPos; XT/t\\Z`U
oSavedFile.seek(nPos); :EW1I>}_
} RFM;?!S
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II'.vp
public synchronized int write(byte[] b,int nStart,int nLen) fhi}x(
{ ?0)K[Kd'Y
int n = -1; 4(8c L?J`0
try{ UDHOcb
oSavedFile.write(b,nStart,nLen); NXD-
n = nLen; y,?=,x}o#
} >4g!ic~O
catch(IOException e) C\{A|'l!x
{ m9h<)D'>
e.printStackTrace (); =2q#- ,t
} S6bW r0XR
rL<N:@HL
<ppdy,j:
return n; 4{>r_^8
} s<*+=aIfu
e;v7!X
dPO"8HQ
} CLND[gc
0}GO$%l
7<LuL
/* YM#'+wl}`
**SiteInfoBean.java "s@Hg1
*/ 1PVZGZxAgv
package NetFox; 'qVlq5.
G/ si( LK
p*K #s1
public class SiteInfoBean { +wG *qI
y/@Bhzc
oW OR7)?r
private String sSiteURL; //Site's URL !I|_vJ@<
private String sFilePath; //Saved File's Path ;FI'nL
private String sFileName; //Saved File's Name HRTNIx
private int nSplitter; //Count of Splited Downloading File Qfp4}a=
^5Y<evjm
7(5d$W
public SiteInfoBean() uj;iE 9
{//nSplitter的缺省值为5 rHk(@T.]
//default value of nSplitter is 5 ~LI}
this("","","",5); e!=7VEB
} w#2apaz
>'n[B
sct3|H#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -Tvnd,
{ |Ja5O
sSiteURL= sURL; qo:Zc`t(R
sFilePath = sPath; {^ BZ#)m|
sFileName = sName; zEjl@Kf
this.nSplitter = nSpiltter; ys!O"=OJ
Dhm;K$T
4~Q<LEly
} p7+>]sqX
!pfpT\i]N:
E9Kp=3H
public String getSSiteURL() "[/W+&z[~
{ (]k Q9}8
return sSiteURL; S#CaJ}M
} ?i_2ueVR
Vuy%7H
t(<k4ji,
public void setSSiteURL(String value) /?BTET
{ IUAe6
sSiteURL = value; irh Z
} 2K3j3|T
l_2Xao$
&n]v
public String getSFilePath() BZOl&G(
{ Z9H2! Cp
return sFilePath; ^0"fPG`
} GRpwEfG
t<+>E_Xw
Z$i?p;HnW
public void setSFilePath(String value) n=f?Q=h\3
{ "4KyJ;RA*
sFilePath = value; Na]ITCVR
} Tb^1#O
1A93ol=
MF$Dx| Tcj
public String getSFileName() 'oGMr=gp<&
{ a^G>|+8
return sFileName; ">B&dNrt
} s o: o b}
}.u[';q]S
gdAd7 T
public void setSFileName(String value) .R)Ho4CE
{ j!L7r'AV5
sFileName = value; BGNZE{K4"
} xn=mS!"1Zo
&]f8Xd
)#Ecm<.^
public int getNSplitter() !#1UTa
{ p]e.E`'S
return nSplitter; ! qtj1.w
} /2r&ga&
fyZtwl@6w#
dXWG`G_
public void setNSplitter(int nCount) E-X02A
{ @CPkP
nSplitter = nCount; :3se/4y}
} R4D$)D
} -R$Q`Xw
Us6~7L00
*Qngx
/* %YuFw|wO
**Utility.java 0m4#{^Y
*/ [ P*L`F
package NetFox; ee<'j~{A
?<OE|nb&
](+u'8
public class Utility { @Rd`/S@
E)'T;%
u#ocx[
public Utility() '*U_!RmQ
{ _0&U'/cs
#pD=TMefC
uYE"OUNWL
} QVb{+`.7
ju.`c->k"
//线程睡眠 x {Rj2~KC
public static void sleep(int nSecond) ? _[q{i{
{ H_iQR9Ak7
try{ ?U:c\TA,m
Thread.sleep(nSecond); @q|c|X:I
} gsIp y
catch(Exception e) Rs'mk6+
{ vN6)Szim
e.printStackTrace (); (^ J2(
} 7*+tG7I @
} JFRbWQ0
U d+6=Us{
//日志 6m9\0)R
public static void log(String sMsg) DI :
{ `'rvDaP
System.err.println(sMsg); xM&`>`;^e
} 4SkCV
0sq?>$~Kc*
Z4k'c+
public static void log(int sMsg) (>\4%(pnD
{ ;MO,HdP;
System.err.println(sMsg); =EHKu|rX~
} P!R`b9_U
} ?R@u'4yK
V4*/t#L/
bM,%+9oz;
/* Z%{`j!!p
**TestMethod.java [Z[ p@Ux
*/ bz\nCfU
package NetFox; H9=8nLb.
Q-e(>=Gv_
|pT[ZT|}G
public class TestMethod { @ +>>TGC
nI`9|W
5N#Sic M
public TestMethod() (]"`>,ray
{ ///xx/weblogic60b2_win.exe >)F)@KAuN4
try{ [WR*u\FF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V4<f4|IL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "6WE6zq
SiteFileFetch fileFetch = new SiteFileFetch(bean); &7w*=f8I
fileFetch.start(); ,u5iiR
} {>yy3(N
catch(Exception e){e.printStackTrace ();} .UUT@ w?
.A7ON1lc^C
%G,d&%f
} +qa^K%K
!$0ozDmD
e$-Y>Dd
public static void main(String[] args) "2 qivJ
{ F,xFeq$/{
new TestMethod(); 239gpf]}
} d?[8VfAnh
} GS,}]c=
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