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)); _)lK.5
} ,v(G2`Z
for(int i=0;i<nEndPos.length-1;i++) owQLAV
{ 2Ask]
nEndPos = nStartPos[i+1]; -0lpsF
} O=ci"2!\-
nEndPos[nEndPos.length-1] = nFileLength; ](^VEm}w;
} NeUpl./b
} %$Mvq&ZZ
M,|o2'
q18dSu
//启动子线程 L[rJ7:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2uV=kqnO
for(int i=0;i<nStartPos.length;i++) :y0'[LV
{ iQ~cG[6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DtyT8kr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h1J-AfV
nStartPos,nEndPos,i); .3oFSc`q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LTG/gif[u
fileSplitterFetch.start(); H~&9xtuHN
} h|_G2p^J+"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M`AbH19
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4{*K%pv\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;z!~-ByzL
nEndPos = " + nFileLength); 2x'JR yef
// fileSplitterFetch[nPos.length-1].start(); to+jQ9q8
0G;RMR':5
ai#0ZgO
//等待子线程结束 ^h=;]vxO
//int count = 0; 65qH
//是否结束while循环 Kq{9:G
boolean breakWhile = false; 4TUe*F@ ML
Z3"f7l6
Ix-FJF-
while(!bStop) {U7j
{ }4\>q$8'
write_nPos(); X=_N7!
Utility.sleep(500); ;\(wJ{u?Y
breakWhile = true; \Ui8Sgeei
v:<u0B-)$
j =[Td
for(int i=0;i<nStartPos.length;i++) g7#_a6
{ ,!PNfJA2
if(!fileSplitterFetch.bDownOver) dLG5yx\js
{ %]RzC`NZ
breakWhile = false; F71.%p7C8"
break; O zY&^:>
} ytr~} M%
} <dh7*M
if(breakWhile) !)KX?i[Q
break; dorZ O2Uc
<eb>/ D
yAXw?z!`O
//count++; <c^m|v
//if(count>4) f`P%aX'cBQ
// siteStop(); |Ax~zk;
} 3>/Yku)t
h5.u W8
8BC}D+q
System.err.println("文件下载结束！"); !Vv$
} ^=FtF9v
catch(Exception e){e.printStackTrace ();} [P,1UO|$B
} -0Y8/6](
{>>f5o3
]hN%~ ~$>
//获得文件长度 A1>R8Zuhy
public long getFileSize() !SKEL6~7
{ oF)+f4
int nFileLength = -1; / IAK'/
try{ { ~FYiX
URL url = new URL(siteInfoBean.getSSiteURL()); GS4!c8>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s3Y \,9\
httpConnection.setRequestProperty("User-Agent","NetFox"); |'b=xeH.^<
jW"C: {Ol;
NA!;#!
int responseCode=httpConnection.getResponseCode(); D 0\
if(responseCode>=400) jvCk+n[
{ UACWs3`s+
processErrorCode(responseCode); pX*Oc6.0mu
return -2; //-2 represent access is error kce+aiv|u
} Dm"GCV
E;9SsA
7YkxIzE
String sHeader; n<y!@p^X
I( G8cK
J'.U+XU
for(int i=1;;i++) S_ e }>-
{ V<?t(_Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sq\oatMw[
//Utility.log(in.readLine()); LKFL2|af
sHeader=httpConnection.getHeaderFieldKey(i); x$?{)EY
if(sHeader!=null) J$v0
{ wYOSaGyZ0I
if(sHeader.equals("Content-Length")) [D^KM|I%+
{ (KK9/k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KPs5? X
break; jx+%X\zokA
} $:t;WXc.<
} r,EIOcz:
else X-e)w
break; W{?7Pn?1`
} |*e >hk
} OtrO"K
catch(IOException e){e.printStackTrace ();} {xMY2I++
catch(Exception e){e.printStackTrace ();} 1wi{lJaz
w*f.Fu(su
$ GL$ iA
Utility.log(nFileLength); KaZ$!JfT
P}KyT?X:
2~K.m@U}!Z
return nFileLength; K9;pX2^z9
} 8m2-fuJz
=ugxPgn
#,0%g1
//保存下载信息（文件指针位置） a)`b;]+9
private void write_nPos() 0' @^PzX
{ ~ubGx
try{ ix=HLF-0zC
output = new DataOutputStream(new FileOutputStream(tmpFile)); @c9VCG D
output.writeInt(nStartPos.length); >s1'I:8
for(int i=0;i<nStartPos.length;i++) bN8GRK )
{ kViX FPW
// output.writeLong(nPos); CZS{^6Ye
output.writeLong(fileSplitterFetch.nStartPos); )K4 |-<i
output.writeLong(fileSplitterFetch.nEndPos); a.y_o50#T
} S=n,unn#t
output.close(); }`{aeVHT
} {r#2X1
catch(IOException e){e.printStackTrace ();} hp@giu7
catch(Exception e){e.printStackTrace ();} NgaX&m`
} H B_si
f|cd_?|
.|NF8Fj
//读取保存的下载信息（文件指针位置） -y1%c^36_J
private void read_nPos() f.!)O@HzH
{ Rq%g5lK
try{ ?PO~$dUc]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +FP*RNM
int nCount = input.readInt(); YYzj:'
nStartPos = new long[nCount]; Q *![u5#
nEndPos = new long[nCount]; h1^q};3!W\
for(int i=0;i<nStartPos.length;i++) ~ou*' w@
{ kQxY"HD
nStartPos = input.readLong(); }:5AB93(
nEndPos = input.readLong(); sZ/~pk
} eva-?+n\q
input.close(); s+gZnne
} 4=9To|U*
catch(IOException e){e.printStackTrace ();} Ix93/FAn
catch(Exception e){e.printStackTrace ();} !?`5r)K
} yS_,lS
cE '`W7&A
Y4sf 2w
private void processErrorCode(int nErrorCode) x JQde4
{ }eXzs_
System.err.println("Error Code : " + nErrorCode); =toqEm~
} iov55jT~l@
6kK\nZ$o$
(30{:o&^
//停止文件下载 ;;pxI5
public void siteStop() c^S^"M|
{ oe}nrkmb
bStop = true; {'4h.PB+r
for(int i=0;i<nStartPos.length;i++) J@54B
fileSplitterFetch.splitterStop(); ,3Y~ #{,i
u.YPb@
g4cmYg3
} *z!!zRh3x
} 4\H:^U&
//负责部分文件的抓取 2-Y%W(bEzs
**FileSplitterFetch.java f^@`[MJj1C
*/ oj /:
package NetFox; S0eD 2
]&`_5pS
H[#s&Fk2
import java.io.*; US A!N
import java.net.*; X2hV)8Sk
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$`W.9
public class FileSplitterFetch extends Thread { U$@p"F@P
)sWdN(E3
axW3#3#`
String sURL; //File URL -yHVydu=
long nStartPos; //File Snippet Start Position RUC V!L
long nEndPos; //File Snippet End Position *lRP ZN
int nThreadID; //Thread's ID /Y_F"GQ
boolean bDownOver = false; //Downing is over TK<~(Dk
boolean bStop = false; //Stop identical dPwe.:
FileAccessI fileAccessI = null; //File Access interface 3 [: x#r
$=uyZTYF)}
}A3(g$8KR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |FGt'
{ b&f;p}C24
this.sURL = sURL; hPLQ)c?
this.nStartPos = nStart; )eop:!m
this.nEndPos = nEnd; }\k"azQ`
nThreadID = id; -Qgu6Ty
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]S<y,d-
} O?/\hZ"&c
i% 19|an
NTS tk{s,
public void run() +h_'hz&HlS
{ Me;@/;c(
while(nStartPos < nEndPos && !bStop) tz\7,yGT
{ m/gl7+
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try{ ; >Tko<
URL url = new URL(sURL); gO_{(\w*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KoZ" yD
httpConnection.setRequestProperty("User-Agent","NetFox"); h<U<KO
String sProperty = "bytes="+nStartPos+"-"; S'#KPzy.
httpConnection.setRequestProperty("RANGE",sProperty); ye=*m
Utility.log(sProperty); 0{#c
"vQ$RW -
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InputStream input = httpConnection.getInputStream(); Oaf!\z}
//logResponseHead(httpConnection); I9O!CQCTt
teH $hd-q
6*9hAnH
byte[] b = new byte[1024]; % \p:S)R
int nRead; ]CsF} wr'z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b3N>RPsHS
{ =Bo(*%
nStartPos += fileAccessI.write(b,0,nRead); 6C@,&2<yK
//if(nThreadID == 1) g N76
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jy?s'tc
} w|!>>W6J
)_N|r$i\
0j\?zt?
Utility.log("Thread " + nThreadID + " is over!"); Se7NF@>9_
bDownOver = true; xvOGE]n
//nPos = fileAccessI.write (b,0,nRead); j_Pt8{[
} 5RCQ<1
catch(Exception e){e.printStackTrace ();} c'B6E1}sx
} v1%rlP
} . #`lW7
;Nf5,D.D
:fz&)e9
//打印回应的头信息 awLN>KI]</
public void logResponseHead(HttpURLConnection con) aTF~rAne<
{ sN0S~}F+
for(int i=1;;i++) N)|mA)S)
{ L1ZhH3}X
String header=con.getHeaderFieldKey(i); yo]!Zn
if(header!=null) %>Z;/j|#r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qXPjxTg{[
Utility.log(header+" : "+con.getHeaderField(header)); ~H!s{$.5
else '0)a|1,
break; fQ c%a1'
} MUsF/1
} ka? |_(
}z:g}".4
)\#w=P
public void splitterStop() 3`[f<XaL
{ mpfc2>6Il.
bStop = true; '7AlE!7%
} KLD)h,]
PhL}V|W>
Q`k=VSUk
} ep`WYR|B
tj/X7|
rUvjc4O}
/* _1jd{?kt
**FileAccess.java Z]f_?@0
*//文件访问(定位，写) ))f%3_H
package NetFox; %B+W#Q`
import java.io.*; Si#I^aF`%
KPO?eeT.WZ
.U|irDO
public class FileAccessI implements Serializable{ nI4Kuz`dF
R!IODXP=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .w=( G
RandomAccessFile oSavedFile; Y/cnj n
long nPos; }pOL[$L
W FVx7
vW,dJ[N6jm
public FileAccessI() throws IOException wz^Q,Od
{ /W&Ro5-
this("",0); 6\>S%S2:
} 5u +U^D
L1=+x^WQ
0G`_dMN
public FileAccessI(String sName,long nPos) throws IOException Sc03vfmo"N
{ h8@8Qw
oSavedFile = new RandomAccessFile(sName,"rw"); 9}p>='
this.nPos = nPos; BoQLjS{kN
oSavedFile.seek(nPos); $D{KXkrd
} S9/oBxGN
c'M#va
,#&\1Vxf
public synchronized int write(byte[] b,int nStart,int nLen) gzfs9e
{ M#o.$+Uh
int n = -1; >i^8K U
try{ On x[}x
oSavedFile.write(b,nStart,nLen); zAT7^q^
n = nLen; wh4ik`S 1
} 7<{g+Q~7*
catch(IOException e) *J[3f]PBmR
{ CqW:m*c
e.printStackTrace (); ?d@3y<A,~
} #ra"(/)
$n_'#m2LE
O.61-rp
return n; $HVus=D"
} ~uqpF-.
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t^eWFX
} X(sHFVU+
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g/Q"%GN,
/* 6*yt^[W
**SiteInfoBean.java Qtj.@CGB
*/ eeKErpj8A
package NetFox; zN}1Qh
A+3,y<j\
7&oT}Z
public class SiteInfoBean { 'Cw&9cL9w
b[5$$_[
R@*mMWW,
private String sSiteURL; //Site's URL Ky"]L~8$
private String sFilePath; //Saved File's Path * V;L|c
private String sFileName; //Saved File's Name oU/CXz?H
private int nSplitter; //Count of Splited Downloading File .|>zQ(7YC
q\+khy,k
OZ{YQ}t{^1
public SiteInfoBean() S$9>9!1>*
{//nSplitter的缺省值为5 SN w3xO!;&
//default value of nSplitter is 5 :cDhqBMNr`
this("","","",5); +/!kL0[v
} ) 0p9I0=
2.''Nt6|
L~x PIu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c6 O1Z\M@\
{ 'Xj9sAB
sSiteURL= sURL; &f12Q&jY7
sFilePath = sPath; w-f[h
sFileName = sName; P#e1?
this.nSplitter = nSpiltter; M#<U=Ha
<'s_3AC
8?p40x$m%
} lw/zgR#|
;F>$\"aG
%x$1g)
public String getSSiteURL() pPI'0x
{ ~W?F.
return sSiteURL; o}EipTL
} >%qk2h>
-P I$SA,
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public void setSSiteURL(String value) Ql~9a [8T~
{ oW0A8_|9
sSiteURL = value; -TIrbYS`
} lqD.epm
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f~U~f}Uw4
public String getSFilePath() 82w;}(!
{ lr>:S
return sFilePath; Xz/5Wis4
} z^@.b
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[VvTR#^
public void setSFilePath(String value) QU`M5{#
{ 4 h}03 oG
sFilePath = value; &b!L$@6
} !m7`E
].E89_|O
U)v['5%
public String getSFileName() G8]DK3#
{ j$2rU'
return sFileName; cJ CKxj
} JCL+uEX4S
qG=?+em
977%9z<h
public void setSFileName(String value) 4!%@{H`3
{ yr4j
sFileName = value; jO` b&]0
} ;3 N0)
r>!$eqX_
_G$SA-W(
public int getNSplitter() + F{hFuHV
{ D'{NEk@
return nSplitter; 18(hrj
} s^atBqw,
(P(=6-0
TH;kJ{[}
public void setNSplitter(int nCount) ny(`An
{ ;$`5L"I5$
nSplitter = nCount; '7lHWqN<
} QNH-b9u>8
} |@84l
& XS2q0-x
NNKI+!vg
/* Z&f@)j
**Utility.java O9+Dd%_KS#
*/ h8nJt>h
package NetFox; *wH.]$
A*1-2
/G{;?R
public class Utility { {B!LhvYAH
H@+1I?l
K;:_UJ>t
public Utility() gdPPk=LD
{ cst}/8e
b"Z$?5
pKxsK^O5[
} IE)$.%q;)
n\-nBrVSf
//线程睡眠 UR3qzPm!0e
public static void sleep(int nSecond) _T96.~Q
{ 1Q5:Vo^B#
try{ d4#CZv[g/
Thread.sleep(nSecond); I_/E0qSJI
} _Q9Mn-&qQ
catch(Exception e) Aof)WKo
{ R6(sWN-
e.printStackTrace (); \ F\ /<
} e_<'zH_1
} W2$MH: j
O c[F
//日志 (6y[,lYH
public static void log(String sMsg) j_(DH2D
{ &["s/!O1R
System.err.println(sMsg); }?\8%hK"a7
} t!=qt*
-qbx:Kk(
[NxC7p:Lo
public static void log(int sMsg) BR*'SF\T
{ K@f@vyw]
System.err.println(sMsg); ifXGH>C
} L:.z FW,
} Bf21u9
8Q{"W"]O7
NsPAWI|4
/* ;u(#-C2^{l
**TestMethod.java *]7$/%.D
*/ -ho%9LW%|
package NetFox; 8[k:FGp>
5 O't-'
<UEta>jj
public class TestMethod { Daw;6f:
@QN(ouqQ
RXi/&'+H
public TestMethod() yd}1Mx
{ ///xx/weblogic60b2_win.exe =O1py_m
try{ W0I)< S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @TQzF-%#7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o]@Mg5(8Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q)IL]S
fileFetch.start(); !y$:}W?_
} cXd?48O
catch(Exception e){e.printStackTrace ();} ee}HQ.}Ja
? PI2X.6
}fV+Kd$CB
} fi,h`mdT?
8v ZY+Q >
; u@& [
public static void main(String[] args) t@;r~Sb
{ 5r)]o'?s
new TestMethod(); V JJ6q
} {f(RYj
} R<)^--n
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