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)); xo WT*f
} wPnybb{
for(int i=0;i<nEndPos.length-1;i++) *{5>XH{ x
{ c3k|G<C2
nEndPos = nStartPos[i+1]; NHkL24ve
} ]US[5)EL-
nEndPos[nEndPos.length-1] = nFileLength; %;O}FyP
} / L~u02?
} Y8ehmz|g]J
H06Bj(Y!
U CY2]E
//启动子线程 )#`H."Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =nVmthGw
for(int i=0;i<nStartPos.length;i++) 6vp0*ww
{ SI*^f\lu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <y>:B}9'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )i!^]|$
nStartPos,nEndPos,i); PayV,8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fe$/t(
fileSplitterFetch.start(); %j{.0H
} :'*DMW~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EXpSh}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *^h_z;{,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K{b-TT 4
nEndPos = " + nFileLength); @GGccF
// fileSplitterFetch[nPos.length-1].start(); 2c:f<>r0y
9Nt3Z>d
\9/1L?@
//等待子线程结束 ;[6&0!N\
//int count = 0; ~FUa:KYD
//是否结束while循环 hz)9"B\S
boolean breakWhile = false; nb+m.X
<k]qH-v4
8(xw?|D7
while(!bStop) i2`0|8mw'
{ >o[|"oLO
write_nPos(); L2|aHI1'l
Utility.sleep(500); U:lv^QPG
breakWhile = true; }*kJ-q&0
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qY(:8yC36
for(int i=0;i<nStartPos.length;i++) T9)wj][ .
{ "=|t~`
if(!fileSplitterFetch.bDownOver) X+ f9q0
{ rsF:4G"%
breakWhile = false; JBcY!dy-d
break; TzM=LvA
} 2QayM?k8
} e.;M.8N#SQ
if(breakWhile) #":a6%0Q
break; JJf<*j^G
L11L23:
fLB1)kTS
//count++; 77We;a
//if(count>4) .3wY\W8Dr-
// siteStop(); o3h-=t
} GLh]G(
D1X{:#|
]\;xN~l
System.err.println("文件下载结束！"); 'G#SLqZy
} A=`*r*
catch(Exception e){e.printStackTrace ();} <qY5SV,
} crn k|o
;^-:b(E
[7\>"v6
//获得文件长度 r nBOj#N
public long getFileSize() }uQ${]&D
{ Do;#NLrWb
int nFileLength = -1; yJD>ny
try{ y1,5$0@G
URL url = new URL(siteInfoBean.getSSiteURL()); f7+Cz>R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r!K|E95oj9
httpConnection.setRequestProperty("User-Agent","NetFox"); &!1}`4$[T
R6@uM<
^:DyT@hQB5
int responseCode=httpConnection.getResponseCode(); N@1p]\
if(responseCode>=400) SrZ50Se
{ o'Y#H r)/
processErrorCode(responseCode); A1_ J sS
return -2; //-2 represent access is error PqEAqP
} +qkMQETV6
mJMq{6;
nem@sB;v#
String sHeader; L[C*@ uK
gq4 . d
,")F[%v
for(int i=1;;i++) \4s;!R!
{ +,_c/(P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mk=#\>
//Utility.log(in.readLine()); S< x:t(
sHeader=httpConnection.getHeaderFieldKey(i); 4/MNqit+
if(sHeader!=null) u~'OcO
{ YIOR$
if(sHeader.equals("Content-Length")) gX*K&*q
{ gaeOgP.0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )N)ljA3]
break; rYGRz#:~+
} _T]>/}}p
} Q]\j>>
else ~`Sle xK|}
break; [ud|dwP"
} yNva1I
} 4<}A]BQVkJ
catch(IOException e){e.printStackTrace ();} ( u f5\}x
catch(Exception e){e.printStackTrace ();} kaFnw(xa
9#@Zz4Ww
IVteF*8hU
Utility.log(nFileLength); !Zs,-=^D
295w.X(J
e1P7 .n}
return nFileLength; -,GEv%6c
} [hU=mS8=^
B||c(ue
kp`0erJqw
//保存下载信息（文件指针位置） 3*WS"bt
private void write_nPos() F]5\YYXO
{ O5;-Om
try{ o!Fl]3F
output = new DataOutputStream(new FileOutputStream(tmpFile)); H#+xKYrp
output.writeInt(nStartPos.length); i<iXHBs
for(int i=0;i<nStartPos.length;i++) <SQ(~xYi
{ 263*: Y
// output.writeLong(nPos); btQet.
output.writeLong(fileSplitterFetch.nStartPos); N!m%~kS9k<
output.writeLong(fileSplitterFetch.nEndPos); T %/
} %F5 =n"
output.close(); ,so4Lb(vG
} %fpsc_
catch(IOException e){e.printStackTrace ();} =pp:j`B9(
catch(Exception e){e.printStackTrace ();} Z#7U "G-A
} kCp)!hVQ
F5IZ"Itu(
BKA]G)G7u!
//读取保存的下载信息（文件指针位置） XGIpUz
private void read_nPos() 8c).8RLf
{ "Ot{^_e
try{ MPvWCPB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /{we;Ut=g
int nCount = input.readInt(); Z| L2oce
nStartPos = new long[nCount]; -f.R#J$2
nEndPos = new long[nCount]; .Cr1,Po
for(int i=0;i<nStartPos.length;i++) @?/\c:cp
{ DV,DB\P$
nStartPos = input.readLong(); Jvj=I82
nEndPos = input.readLong(); GCH[lb>IJv
} rfTe
input.close(); XnY"oDg^>
} J wFned#T
catch(IOException e){e.printStackTrace ();} o?dR\cxj
catch(Exception e){e.printStackTrace ();} la702)N{
} BD'NuI
hbnS~sva
!KDr`CV&
private void processErrorCode(int nErrorCode) +H}e)1^I
{ D3.VXuKn6
System.err.println("Error Code : " + nErrorCode); T6=-hA^A
} ;eh/_hPM
[;@):28"
" $=qGHA~
//停止文件下载 (}0S1)7t
public void siteStop() cY~M4:vgT
{ OPiaG!3<
bStop = true; M.[wKGX(
for(int i=0;i<nStartPos.length;i++) Ff)@L-Y\K
fileSplitterFetch.splitterStop(); P;c0L;/
(H-cDsh;c
NL-_#N$
} R&!]Rl9hf
} ,Hh*3rR^
//负责部分文件的抓取 4W-"|Z_x
**FileSplitterFetch.java -fPT}v
*/ e YDUon
package NetFox; -yA3 RP
% $.vOFP9
' =}pxyg
import java.io.*; $rTu6(i1
import java.net.*; 6$(0Ty
h--45`cE
>[P%Ty);
public class FileSplitterFetch extends Thread { l/F!Bq[*g
os_WYQ4>j
dyl 0]Z
String sURL; //File URL O+vcs4
long nStartPos; //File Snippet Start Position OQc{ V
long nEndPos; //File Snippet End Position {? 2;0}3?;
int nThreadID; //Thread's ID N(BiOLZL6
boolean bDownOver = false; //Downing is over j%5a+(H,z;
boolean bStop = false; //Stop identical x~Cz?ljbn
FileAccessI fileAccessI = null; //File Access interface HTN$ >QTI
3W'FcE)|E
ol#yjrv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4Pf+]R
{ "ZqEP R)
this.sURL = sURL; raF] k0{
this.nStartPos = nStart; @Wz%KdXA
this.nEndPos = nEnd; m0C{SBn-M
nThreadID = id; 0@v2*\D#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UAKu_RO6S
} D&f!( n
%r P !
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public void run() F-tFet
{ Se/ss!If
while(nStartPos < nEndPos && !bStop) N-Z^G<[q.
{ ,\}k~ U99
%GVN4y&
) H+d.Y
try{ nj"m^PmWo3
URL url = new URL(sURL); _j>L4bT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e3pnk =u
httpConnection.setRequestProperty("User-Agent","NetFox"); ]*GnmG:D*
String sProperty = "bytes="+nStartPos+"-"; GjLW`>
httpConnection.setRequestProperty("RANGE",sProperty); <b'1#Pd>0
Utility.log(sProperty); :ovt?q8">
{RJ52Gx(
}v&K~!*
InputStream input = httpConnection.getInputStream(); ( mt*y]p?
//logResponseHead(httpConnection); `OBl:e
g+3Hwtl
W W35&mI)k
byte[] b = new byte[1024]; kAt RY4p
int nRead; GqMB^Ad
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q2FQhc@L(:
{ X7b!;%3@
nStartPos += fileAccessI.write(b,0,nRead); S!<"Swf:
//if(nThreadID == 1) wO89&XZ<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %2,/jhHL
} :-U53}Iy
FF jRf
p$XnOh
Utility.log("Thread " + nThreadID + " is over!"); Qqh^E_O
bDownOver = true; lm!FM`m
//nPos = fileAccessI.write (b,0,nRead); ]h0Y8kpd
} SNN#$8\
catch(Exception e){e.printStackTrace ();} RB *P0
} K9^"NS3
} &AJUY()8
_V&x`ks
*cPN\Iu.W
//打印回应的头信息 yduuFK
public void logResponseHead(HttpURLConnection con) wZ O@J|
{ ^t7_3%%w
for(int i=1;;i++) oLd:3,p}
{ X= SG
String header=con.getHeaderFieldKey(i); 8M~u_`6
if(header!=null) vU7&'ca
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EFeAr@nj
Utility.log(header+" : "+con.getHeaderField(header)); A^t"MYX@
else 88#N~j~P
break; B9AbKK$`
} b70AJe=
} vLr&ay!w
lqauk)(A0
8'n#O>V@
public void splitterStop() HMhLTl{;
{ d0TgqO{
bStop = true; *0lt$F$~b
} K1<k+t/V
JLml#Pu4
u!M&;QL
} "7:u0p!
k,AM]H
F~%|3a$Y
/* 8cB=}XgYS
**FileAccess.java @::lJDGVv
*//文件访问(定位，写) 50COL66:7
package NetFox; J#+Op/mmo
import java.io.*; *Q0lC1GQ
BL7>dZOa
,Io0ZE>`V
public class FileAccessI implements Serializable{ NWeV>;lh9
5%'o%`?i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t&38@p
RandomAccessFile oSavedFile; $4sAnu]
long nPos; 80dSQ"y
w~ijD ^g
$f9 ,##/
public FileAccessI() throws IOException ,=yOek}
{ W%=Zdm rv
this("",0); &:-GI)[o
} C"(_mW{@
B5D3_iX]
9#ZzE/
public FileAccessI(String sName,long nPos) throws IOException :J<Owh@
{ 8qn{
oSavedFile = new RandomAccessFile(sName,"rw"); F|9a}(-7
this.nPos = nPos; r}Ltv?4
oSavedFile.seek(nPos); u6]gQP">I
} { 576+:*
gfV]^v
9+W!k^VWq
public synchronized int write(byte[] b,int nStart,int nLen) RzMA\r;#
{ X #&(~1O
int n = -1; w 7Cne%J8
try{ >xklt"*U,
oSavedFile.write(b,nStart,nLen); SlR7h$r'
n = nLen; ?56~yQF/2
} |C^ c0
catch(IOException e) tWcizj;?wK
{ ^ sS>Mts
e.printStackTrace (); w{RNv%hJ$=
} r4;^c}
"0!~g/X`rK
dBsRm{aS
return n; *sjj"^'=
} HI}pX{.\
i-|/2I9%
,xm;JXJ
} )-MA!\=<
}_Tt1iai*
u}Lc|_ea`
/* 0TpBSyx.
**SiteInfoBean.java qn5yD!1
*/ vd2uD2%con
package NetFox; :y4)qF
(7M^-_q]D
0*/mc96
public class SiteInfoBean { (xI)"{
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z4 GN8:~x
private String sSiteURL; //Site's URL AN|jFSQ'
private String sFilePath; //Saved File's Path 4he v ;
private String sFileName; //Saved File's Name Z&AHM &,yj
private int nSplitter; //Count of Splited Downloading File r))$XM
6-)7:9y
=x|##7
public SiteInfoBean() Bl>_&A)
{//nSplitter的缺省值为5 ho?|j"/7
//default value of nSplitter is 5 Oz"@yL}
this("","","",5); e-L5=B
} 67Af} >Q
XLkL#&Ir
_lP4ez Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ukk-(gjX
{ UchALR^5
sSiteURL= sURL; i{Y=!r5r
sFilePath = sPath; Z!q2F%02FO
sFileName = sName; AAIyr703cQ
this.nSplitter = nSpiltter; @2x0V]AI
=NVZ$KOZ
fvAh?<Ul
} [lDt0l5^
M="WUe_
eO|^Lu]+
public String getSSiteURL() jhjW*F<u
{ ]# tGT0
return sSiteURL; $Uv<LVd(
} ]be0I)
gJ)h9e*m^
4~]8N@Bii
public void setSSiteURL(String value) $@+p~)r(l
{ >Hd~Ca>
sSiteURL = value; |r)>bY7
} ,kGw;8X
N"q+UCRC
UUdu;3E=5
public String getSFilePath() $sd3h\P&R
{ )A>U<n$h
return sFilePath; Zi[{\7a
} wiK@o$S-
lOowMlf@2
~pX(w!^
public void setSFilePath(String value) /iuUUCk
{ 3iwoMrp
sFilePath = value; "w:\@Jwu(
} u8{@PlS
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?<>,XyY
public String getSFileName() X:xC>4]gG'
{ D7gX,e
return sFileName; Knw'h;,[
} _D7HQ
H3UX{|[
o2 T/IJP
public void setSFileName(String value) 34++Rr [G
{ Mc#O+'](f
sFileName = value; vV:MS O'r
} R:pBbA7E
qH{8n`
-Y 6.?z
public int getNSplitter() Nj3^"}V
{ s)o,Fi
return nSplitter; k#IS,NKE
} R%]9y]HQ
7YQK@lS
T}b( M*E
public void setNSplitter(int nCount) :?&WKW
{ IgHs&=
nSplitter = nCount; QYf/tQg$
} &4[#_(pk
} ~Uwr689N
rlUdAa3
K[Egwk7
/* <x>k3bD
**Utility.java 5m%baf2_
*/ alb+R$s
package NetFox; ]"2 v7)e
3-_U-:2"
<L!~f`nH2
public class Utility { U4^p({\|-
]U^d1&k
\^;|S
public Utility() fn?6%q,!ls
{ ;I`,ZKY
|Ad6~E+aL-
gvRc:5B[
} :>er^\
\0^rJ1*
//线程睡眠 t7*H8
public static void sleep(int nSecond) ?V\9,BTb)
{ KHc/x8^9
try{ "[".3V
Thread.sleep(nSecond); Cr V2 V)|G
} ~\@<8@N2a6
catch(Exception e) :}3qZX
{ iuU3*yyn
e.printStackTrace (); wE8a4.
} /F8\%l+
} xJF6l!`
W:+2We@
//日志 oX:1 qJrC
public static void log(String sMsg) _'v }=:X
{ Y+"hu2aPkY
System.err.println(sMsg); [ilv/V<
} d6d(?"
x9o^9QJh
xJH9qc ME
public static void log(int sMsg) -Y jv&5
{ 0@mX4.!
System.err.println(sMsg); 8)q]^
} yZ(Nv $[5
} yK>0[6l
q:~`7I
3Ld ;zW
/* +{Vwz
**TestMethod.java sKB-7
*/ amk42
package NetFox; ubN"(F:!-S
SU#P.y18%
< jocfTBk
public class TestMethod { .^`a6>EQ)|
+'&_V011<
I}G}+0geV
public TestMethod() /YugQ.>| l
{ ///xx/weblogic60b2_win.exe }Cq9{0by?a
try{ sh))[V"8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dxa)7dA|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T.m)c%]^/
SiteFileFetch fileFetch = new SiteFileFetch(bean); I;11j
fileFetch.start(); D-+)M8bt
} @|UIV
catch(Exception e){e.printStackTrace ();} C+#;L+$Gi
kO`3ENN
k.%W8C<Pa
} 1KIq$lG{ E
o YI=p3l
zs]/Y2
public static void main(String[] args) LG@c)H74
{ }A'<?d8
new TestMethod(); Hb AMoow!
} MCrO]N($b
} l^eNZ3:H
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