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)); X?R |x[
} ,m:6qdN
for(int i=0;i<nEndPos.length-1;i++) .v\PilF
{ jOv~!7T
nEndPos = nStartPos[i+1]; H@4/#V|Uy
} qS|AdkNL
nEndPos[nEndPos.length-1] = nFileLength; E#aZvE
} gZ*hkKN6
} N;g$)zCV1
]\`w1'*
TwUsVM(~
//启动子线程 %}ixgs7*c0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^ `je
for(int i=0;i<nStartPos.length;i++) *k4+ioFnKE
{ L W?&a3e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V $>"f(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ([tG y
nStartPos,nEndPos,i); D Kq-C%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ? osfL
fileSplitterFetch.start(); QheDF7'z
} A'`P2Am
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a-:pJE.'p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 716hpj#*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z 7@ 'CJ
nEndPos = " + nFileLength); q}e]*]dJZ
// fileSplitterFetch[nPos.length-1].start(); POY=zUQ'/
BJ2Q2WW
oAaf)?8
//等待子线程结束 ^9s"FdB]24
//int count = 0; E)Srj~$d
//是否结束while循环 :cb[M5c
boolean breakWhile = false; -aT=f9u
5Fh8*8u6hL
.5NZf4:C
while(!bStop) rXuAixu!t
{ .c03}RTC^
write_nPos(); (qbc;gBy
Utility.sleep(500); #.b^E3#+
breakWhile = true; *.xZfi_|
Stt* 1gT
MorW\7-}
for(int i=0;i<nStartPos.length;i++) }`#Bf
{ BPqwDjW
if(!fileSplitterFetch.bDownOver) YY\Rua/nG
{ h)P]gT0f/
breakWhile = false; v/x*]c!"`
break; @EYK(QS-
} (]}XLMi,|!
} 4[Z1r~t\L
if(breakWhile) *n,UOHlO
break; 69rwX"^
I IYLA(
\3M1.Q4$Gr
//count++; hg{ &Y(J!U
//if(count>4) M{G$Pk8[
// siteStop(); jXtLo,km
} o;%n,S8J|^
lR,G;
YyG~#6aCh
System.err.println("文件下载结束！"); vmMV n-\#
} A=W5W5l(>
catch(Exception e){e.printStackTrace ();} \ x:_*`fU
} Up'."w_zE
SK}HXG{?
2=Jmi?k
//获得文件长度 7f[8ED[4
public long getFileSize() z(#=tC|
{ [rc'/@L
int nFileLength = -1; -}NAb^d
try{ [O [FCn
URL url = new URL(siteInfoBean.getSSiteURL()); '8L(f w{k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :C>J-zY
httpConnection.setRequestProperty("User-Agent","NetFox"); o%$<LaQG5
=>P_mPP=
5=*@l
int responseCode=httpConnection.getResponseCode(); )\(lg*?:
if(responseCode>=400) 6NU8HJp
{ )ynA:LXx
processErrorCode(responseCode); 2YaTT& J
return -2; //-2 represent access is error ~>4@;
} t&8<k+m
G[vUOEU~O
a pKa4nI
String sHeader; g<0w/n!jmC
|3aS17yL>
J6= w:c
for(int i=1;;i++) 1k*n1t):
{ MM=W9#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q#.rYzl0
//Utility.log(in.readLine()); LRhP7D+A
sHeader=httpConnection.getHeaderFieldKey(i); }rFThI
if(sHeader!=null) w/hh 4ir
{ A>H*`{}
if(sHeader.equals("Content-Length")) $>nkGb%Kp
{ S.qk%NTTD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t*eleNYeS~
break; O7!fI'R
} UUZ6N ZQI
} e=0l<Rj
else :v|r=#OI
break; ](]*]a4ss
} $:xF)E
} u XaL
catch(IOException e){e.printStackTrace ();} Wdei`u[
catch(Exception e){e.printStackTrace ();} e?_c[`sg
n$nne6|O
cC7"J\+r*
Utility.log(nFileLength); H9.oVF^~
{yGZc3e1j
Kc%tnVyGh:
return nFileLength; {vf+sf^^q
} G~Sy&XJuq
aOaF&6'j
N02zPC 8
//保存下载信息（文件指针位置） K<Yn_G
private void write_nPos() ';i"?D?NAk
{ \=HfO?$ Ro
try{ FSI]k:
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^yzo!`)fso
output.writeInt(nStartPos.length); a*pXrp@
for(int i=0;i<nStartPos.length;i++) 0+$hkd n
{ 2&zn^\%"
// output.writeLong(nPos); & y#y>([~
output.writeLong(fileSplitterFetch.nStartPos); 9_g>BI;"8
output.writeLong(fileSplitterFetch.nEndPos); dqIZ#;:g
} D}=/w+
output.close(); |JirBz
} DQL06`pX/
catch(IOException e){e.printStackTrace ();} KIXwx98
catch(Exception e){e.printStackTrace ();} o06A=4I
} 'vqj5YTj
i{%z
?,A}E|jZ
//读取保存的下载信息（文件指针位置） kKFuTem_3
private void read_nPos() )Tyky%P+iI
{ P wt ?9I
try{ n"K {uj))
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;'b!7sMO~
int nCount = input.readInt(); hfl%r9o
nStartPos = new long[nCount]; 5`OK-
nEndPos = new long[nCount]; ;EE{~
for(int i=0;i<nStartPos.length;i++) |SSfG~r
{ jQH5$
nStartPos = input.readLong(); =B3!jir
nEndPos = input.readLong(); FFD*e-i
} GU;TK'Yy?
input.close(); uFA|rX
} *il]$i
catch(IOException e){e.printStackTrace ();} 0ECO/EuCg
catch(Exception e){e.printStackTrace ();} %XDip]+rb
} A>&>6O4
Bd N{[2
sWojQ-8}
private void processErrorCode(int nErrorCode) Wo1V$[`Dy
{ F3H:I"4
System.err.println("Error Code : " + nErrorCode); _oMs `"4K
} 5JXzfc9rL
u"Hd55"&
\'}/&PCkr
//停止文件下载 jL>I5f
public void siteStop() N9>'/jgZX
{ sqMNon`5
bStop = true; ?,+C!R?
for(int i=0;i<nStartPos.length;i++) >8F{lbEe
fileSplitterFetch.splitterStop(); E980yXJR
)Rm 'YmO
:yFTaniJ'.
} g:uaI
} ctwhfS|Y0
//负责部分文件的抓取 + !E{L
**FileSplitterFetch.java '<{oYXZW3
*/ f:JYG]E&
package NetFox; Fw_bY/WN{
)ZQ9a4%
Aoy1<8WP%
import java.io.*; .zSimEOF
import java.net.*; l1iF}>F2
%BKR}
Z<,CzKs+||
public class FileSplitterFetch extends Thread { #1,>Qnl
EP*["fx
!4b;>y=m
String sURL; //File URL %0y3/W
long nStartPos; //File Snippet Start Position 0Tn|Q9R
long nEndPos; //File Snippet End Position c9cphZ(z
int nThreadID; //Thread's ID {C,1w
boolean bDownOver = false; //Downing is over yv#c=v|
boolean bStop = false; //Stop identical 8g2-8pa{
FileAccessI fileAccessI = null; //File Access interface *Wuctu^9
]y)R C-N
]<o.aMdV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (x@i,Ba@
{ ^V0{Ew/x
this.sURL = sURL; c5mhl;+'
this.nStartPos = nStart; ;'WzfJ!q
this.nEndPos = nEnd; -Uhl9 =
nThreadID = id; C^8)IN=$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U d=gdsL
} 3 DO$^JJ.
C.9eXa1wkT
)T$fk
public void run() M#8Ao4 T
{ X~Rk ,d3
while(nStartPos < nEndPos && !bStop) 71n uTE%!
{ i"\AyKiJ
~gLEhtW
w'zO(6 `
try{ Fh!!T%5>C
URL url = new URL(sURL); \aJ-q?=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0u&?Zy9&
httpConnection.setRequestProperty("User-Agent","NetFox"); uYFcq
String sProperty = "bytes="+nStartPos+"-"; /PB3^d>Q2
httpConnection.setRequestProperty("RANGE",sProperty); 61Iy{-/ZV
Utility.log(sProperty); >I8hFtAM
65`'Upu
.KwuhmR
InputStream input = httpConnection.getInputStream(); a@a1TpLQ
//logResponseHead(httpConnection); %\zCOfN
l_q>(FoqA
[:hy
byte[] b = new byte[1024]; L_zmU_zD
int nRead; [Yahxw}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (82\&dfy
{ KiRt'
nStartPos += fileAccessI.write(b,0,nRead); @)juP- o%
//if(nThreadID == 1) MF`k~)bDV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "<n"A7e
} /x8C70W^
*O}'2Ht6\
M]/wei"X
Utility.log("Thread " + nThreadID + " is over!"); .V)2Tz
bDownOver = true; ??e#E[bI
//nPos = fileAccessI.write (b,0,nRead); OTtanJ?
} YI\Cs=T/
catch(Exception e){e.printStackTrace ();} c7TWAG_+
} 5P t}
} [,szx1
t[yD8h
;x0KaFk
//打印回应的头信息 H7XxME
public void logResponseHead(HttpURLConnection con) +Tc(z{;
{ )}9}"jrDlx
for(int i=1;;i++) 3=L1HZH
{ F>_lp,G
String header=con.getHeaderFieldKey(i); mX_Uhpw?t
if(header!=null) ~9/nx|%D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t-|=weNy
Utility.log(header+" : "+con.getHeaderField(header)); 'JKvy(n>
else u1|Y;*
break; 2T2#HP
} WZ V*J&
} \#oV<MR
Ckl]fy@D}
JU2' ~chh
public void splitterStop() )yH#*~X_
{ I:>d@e/;
bStop = true; <x;[ H%
} 5J2p^$s
\iLd6Qo_aq
`kT$Gx4x
} GC#95
S0QU@e
&I'F-F;
/* xfV2/A#h
**FileAccess.java :IKp7BS
*//文件访问(定位，写) P}u<NPy3Q
package NetFox; &i}cC4i
import java.io.*; B>nd9Z '
`3s-%>
Nn4Kt,KY
public class FileAccessI implements Serializable{ !I+u/f?TO7
,`2xfVa-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g$+O<a@n
RandomAccessFile oSavedFile; c94PWPU
long nPos; cFNtY~(b
3&d+U)E
J-{E`ibGN
public FileAccessI() throws IOException @5@{Es1u
{ T-cVM>u\D
this("",0); D)eKq!_
} >0okb3+
gwjv&.T6^
)Zr0_b"V:e
public FileAccessI(String sName,long nPos) throws IOException &aht K}u
{ lukRFN>c"
oSavedFile = new RandomAccessFile(sName,"rw"); DG9;6"HBX
this.nPos = nPos; 0<Y&2<v
oSavedFile.seek(nPos); ?#y<^oNM
} [5#/&k{
lz5j~t5>Q
x};g!FYfkB
public synchronized int write(byte[] b,int nStart,int nLen) sOHAW*+
{ 6Kc7@oO~
int n = -1; /PuWJPy;
try{ L ]'CA^N
oSavedFile.write(b,nStart,nLen); 2%%U)|39mB
n = nLen; aRKG)0=
} 1{glRY'
catch(IOException e) ,<WykeC
{ lMf5F8
e.printStackTrace (); , &f20o
} )8>f
O g~"+IGp
{8Nd-WJ{
return n; lGgKzi9VD
} c{P`oB8
W n mRRq^
qq{N; C
} ]lG\t'R
&otgN<H9
i58CA?
/* Yx/~8K_%M?
**SiteInfoBean.java }Q(I&uz
*/ At|tk
package NetFox; 3CRBu:)m
9!C?2*>A P
74OM tLL$
public class SiteInfoBean { wZb@VG}%
a6#PZ!1
^aoLry&i=
private String sSiteURL; //Site's URL 6Ky"4\e
private String sFilePath; //Saved File's Path W5;sps
private String sFileName; //Saved File's Name LA Vgf>
private int nSplitter; //Count of Splited Downloading File {vlh,0~
Oz7v hOU
1 niTkop
public SiteInfoBean() #-,`4x$m|
{//nSplitter的缺省值为5 $B/cj^3
//default value of nSplitter is 5 e28#Yh@U
this("","","",5); RuuU}XQ
} wfzb:Aig`
$ wB
6&T1 ZY`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g?M69~G$:x
{ r!uAofIi_
sSiteURL= sURL; &|;!St]!M
sFilePath = sPath; GTe9@d
sFileName = sName; bV,R*C
this.nSplitter = nSpiltter; @/iLC6QF
ti% e.p0[
Uij$ eBN
} K`<P^XJr
GUXX|W[6
o(qmI/h
public String getSSiteURL() "j>0A Hem
{ \H(,'w7H
return sSiteURL; +[DVD
} gk`.8o
s1q d/
S22;g
public void setSSiteURL(String value) uIwyan-
{ lEs/_f3;A
sSiteURL = value; 3!x)LUWfWY
} )9->]U@
de=T7,G#
LlqhZetS
public String getSFilePath() oPir]`re
{ w{IqzmPiH
return sFilePath; -nSqB{s!SD
} >6q@Tr
j>23QPG`6U
"bH ~CG:Y
public void setSFilePath(String value) q<7n5kJ~
{ 2{N0. |5
sFilePath = value; 0qd`Pf
} `^[ra%a
V5MbWXgR
Hua8/:![+
public String getSFileName() h,g~J-x`|
{ ZAwl,N){
return sFileName; w@We,FUJN
} j!dklQh0
\ZH=$c*W
,sK-gw
public void setSFileName(String value) }S4Fy3)
{ c,^-nH'X>
sFileName = value; FTe#@\I
} =t2epIr5
NKws;/u
ImVe71mh
public int getNSplitter() ^;d;b<
{ Y*f<\z(4
return nSplitter; LTHS&3%2
} S;~_9i]upe
F(r&:3!97
C&gJP7UF
public void setNSplitter(int nCount) XJ+sm^`vOf
{ 9q?gmAn.
nSplitter = nCount; }$ der
} 7=9jXNk Y
} I g`#U~
W7 $yE},z
H;8(y4;
/* Qk= w ,`
**Utility.java 4p]Y`];U
*/ %{Gqhb=u\
package NetFox; 5"+* c@L
a%kj)ah
!jm a --
public class Utility { G>b1No3%k
8}&cE#@
7^1ikmYY
public Utility() [0$Y@ek[
{ `?:'_Ki
0)Z7U$
o?>)CAo
} N{'k ]&
zI(Pti
//线程睡眠 Z'E@sc 9
public static void sleep(int nSecond) 9iUw7-)
{ ;8!D8o(+
try{ +=O:z *O
Thread.sleep(nSecond); ;iEqa"gO
} E_? M&
catch(Exception e) <]<50
{ m~v Ie c
e.printStackTrace (); EpiagCS
} xnArYm
} /cg!Ap5
/Wa+mp
//日志 ],LOkAX
public static void log(String sMsg) 2:]Sy4K{
{ 0o#lB^e;l
System.err.println(sMsg); 5v]xk?Eb
} 6-oQs?
` H"5nQRV
NQb?&.C
public static void log(int sMsg) 8/=2N
{ L.5GX 29
System.err.println(sMsg); 8w\&QX
} 4P.ry|2
} Sdn] f4
."2V:;;
.]" o-(gB
/* )}EwEM
**TestMethod.java 87-oR}/r
*/ Y=5hm
package NetFox; rkD(KG9E
%Z.!Bm:
EV}%D9:
public class TestMethod { Xd4~N:
D=8=wT2<
@8 pRIS"V
public TestMethod() N7NK1<vw2
{ ///xx/weblogic60b2_win.exe V/03m3!q
try{ >uVG]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F$caKWzny5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !$O +M#
SiteFileFetch fileFetch = new SiteFileFetch(bean); H.YntFtD'
fileFetch.start(); #e=[W))
} p}h)WjC
catch(Exception e){e.printStackTrace ();} v +7<}
a{y;Ub
P:Bg()
} n|8fdiK#}
c+q4sNnE
OH&&d=~
public static void main(String[] args) 1vX97n<}
{ YM5;mPR
new TestMethod(); NpSS/rd $
} [z/OY&kF
} EayZ*e]
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