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)); 6^W6As0
} qf/1a CQiP
for(int i=0;i<nEndPos.length-1;i++) +Zaew679
{ D;f[7Cac
nEndPos = nStartPos[i+1]; \hjGw,d
} 16iymiLz&
nEndPos[nEndPos.length-1] = nFileLength; R&w2y$
} c0J=gZiP
} |G2hm8 Y
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"2>I?
//启动子线程 0jS"PH?[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i\P?Y(-{
for(int i=0;i<nStartPos.length;i++) - nWs@\
{ 45Z"U<I,9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8+m[ %5lu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Qfhhceb6#J
nStartPos,nEndPos,i); %5N;SRtv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @WppiZ$
fileSplitterFetch.start(); R&z)
} ;z6Gk&?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JvA6kw,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kmJ{(y)w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PGT*4r21
nEndPos = " + nFileLength); Qg)=4(<Hr
// fileSplitterFetch[nPos.length-1].start(); (nhv#&Fd+
br!:g]Vh
S(7_\8h
//等待子线程结束 b&LfL$
//int count = 0; I91pX<NBf
//是否结束while循环 ;Nw.
boolean breakWhile = false; b>N)H
8>:kv:MId
QN%w\JXS
while(!bStop) ?/mkFDN
{ *. H1m{V
write_nPos(); xS~OAcxg
Utility.sleep(500); LPjsR=xi
breakWhile = true; DVu_KT[Hd
4dDDi,)U
=F!DwaZ
for(int i=0;i<nStartPos.length;i++) u3!aKXnv<
{ rm7$i9DH2
if(!fileSplitterFetch.bDownOver) &&iZ?JteZ
{ jTNfGu0x
breakWhile = false; F&{RP>
break; o<`)cb }
} Sz\"*W;>
} @w1@|"6vF
if(breakWhile) | v? pS
break; 9/lCW
< V?CM(1C
B]PTe~n^
//count++; H'Mc]zw_,
//if(count>4) zj!&12w%3
// siteStop(); $#4J^(I*:
} 5XO eYO{
fvajNP
V?g@pnN"
System.err.println("文件下载结束！"); >Z#=<
} Wsn}Y-x
catch(Exception e){e.printStackTrace ();} Nw'3gJ:
} j@0/\:1(U
\NYtxGV[Z
X-oHQu5
//获得文件长度 Q AJX7
public long getFileSize() B;M{v5s~]
{ 39;Z+s";
int nFileLength = -1; =*q|568
try{ lVywc:X
URL url = new URL(siteInfoBean.getSSiteURL()); RjO9E.nm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I0 y+,~\
httpConnection.setRequestProperty("User-Agent","NetFox"); =<-tD<
55vpnRM
'1)BZ!
int responseCode=httpConnection.getResponseCode(); CIt>D'/YT
if(responseCode>=400) Rd5ni2-nve
{ %0]vW;Q5
processErrorCode(responseCode); W)"PYC4
return -2; //-2 represent access is error +):t6oX|
} I*e85wef
G Q&9b_
m178S3
String sHeader; S7-ka{S
Jji~MiMn
dhe?7r]u
for(int i=1;;i++) X!5
{ 7s%DM6li 6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [Rh[Z#6
//Utility.log(in.readLine()); W~GbB:-
sHeader=httpConnection.getHeaderFieldKey(i); 8?S32Gdu
if(sHeader!=null) Q]_3 #_'
{ zr9o
if(sHeader.equals("Content-Length")) V/Hjd`n)`i
{ 'hl>pso.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .BsZ.!MPL(
break; &z;;Bx0s
} Bcx-t)[
} Q)\7(n
else qvz2u]IOw
break; Wjt1NfS&
} `nccRy<l
} a^qLyF&F
catch(IOException e){e.printStackTrace ();} Nw@tlT4
catch(Exception e){e.printStackTrace ();} DG8LoWZ
_8C0z=hz
iw<#V&([J
Utility.log(nFileLength); Wvl>iHB
\oF79
yp=Hxf
return nFileLength; LTu cs}
} 03*` T
>_QC_UX>4i
VOBzB]
//保存下载信息（文件指针位置） u7>b}+ak&
private void write_nPos() @sly-2{e1
{ D'aq^T'
try{ 0$3\DS<E
output = new DataOutputStream(new FileOutputStream(tmpFile)); QRj><TKi
output.writeInt(nStartPos.length); {aI8p}T
for(int i=0;i<nStartPos.length;i++) 4l2i'H
{ 6#XB'PR2p
// output.writeLong(nPos); \^iPU 27H
output.writeLong(fileSplitterFetch.nStartPos); &?^S`V8R*
output.writeLong(fileSplitterFetch.nEndPos); E 3b`GRay
} Y)Y`9u<?
output.close(); <@FOqi{o{
} <Vyv)#32o3
catch(IOException e){e.printStackTrace ();} orn9;|8q
catch(Exception e){e.printStackTrace ();} p<>%9180!F
} <,d.`0:y
^yH!IRRAq
s z
//读取保存的下载信息（文件指针位置） 2wE?O^J
private void read_nPos() E"5 zT1d
{ #q1Qa_LXc
try{ U'S}7gya
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]Q=D'1MM
int nCount = input.readInt(); "bAkS}(hB(
nStartPos = new long[nCount]; 43pQFDWa
nEndPos = new long[nCount]; <=8REA?
for(int i=0;i<nStartPos.length;i++) 6k;__@B,
{ LRBcW;.Su
nStartPos = input.readLong(); 7QP%Pny%
nEndPos = input.readLong(); fk)ts,p?
} ?Y2ZqI
input.close(); ~vnG^y>%
} zVe@`gc
catch(IOException e){e.printStackTrace ();} N2uxiXpQZ=
catch(Exception e){e.printStackTrace ();} Vh^fbv`?
} yfeX=h
)n 1b
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private void processErrorCode(int nErrorCode) Z<ozANbk
{ yiGq?WA7
System.err.println("Error Code : " + nErrorCode); j<>|Hi #`
} ^,')1r,
24"Trg\WK[
tLe!_p)
//停止文件下载 Q=J"#EFs
public void siteStop() !7!xJ&/V
{ 8;;!2>N
bStop = true; v!?bEM3D
for(int i=0;i<nStartPos.length;i++) H];|<G
fileSplitterFetch.splitterStop(); R*IO%9O
A_1cM#4
d_=@1JM>
} 8RWfv}:X
} %)T>Wn%b]v
//负责部分文件的抓取 ')t :!#
**FileSplitterFetch.java +[*VU2f t
*/ }\}pSqW
package NetFox; `E>HpRcxD
L<!}!v5ja
:#58m0YLA:
import java.io.*; Xn-GSW3{
import java.net.*; \y^Od7F
M>dP 1
I&]d6,
public class FileSplitterFetch extends Thread { |WH'aGG
QlJ cj+_h
"P HkbU
String sURL; //File URL {8UYu2t
long nStartPos; //File Snippet Start Position *"` dO9Yf_
long nEndPos; //File Snippet End Position qLBXyQ;U
int nThreadID; //Thread's ID Y~Y-L<`I
boolean bDownOver = false; //Downing is over 9{|JmgO!
boolean bStop = false; //Stop identical F<q'ivj:w
FileAccessI fileAccessI = null; //File Access interface m\`dLrPX4j
zF6R\w
R/r)l<X@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5=tvB,Ux4
{ 3TqC.S5+
this.sURL = sURL; w@Uw8b
this.nStartPos = nStart; LnIln[g:
this.nEndPos = nEnd; w~a^r]lPW
nThreadID = id; PVHJIB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~4h<nc
} 6s\niro2
S[!K
){`s&?M0
public void run() :b)IDcW&j:
{ HQ~`ha.
while(nStartPos < nEndPos && !bStop) %JM:4G|q
{ ~K}iVX
$2qZds[
R06L4,/b
try{ $X8(OS5d'
URL url = new URL(sURL); }S51yDVG_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tFt56/4
httpConnection.setRequestProperty("User-Agent","NetFox"); zY~
String sProperty = "bytes="+nStartPos+"-"; ZC 7R f
httpConnection.setRequestProperty("RANGE",sProperty); ~Q"3#4l
Utility.log(sProperty); ^;jJVYx-PP
^T@ (`H4@
bh|M]*Pq
InputStream input = httpConnection.getInputStream(); yQE|FbiA
//logResponseHead(httpConnection); eznt "Rr2
Hs/ aU_
lo*OmAF
byte[] b = new byte[1024]; AE`X4q
int nRead; i2KN^"v?N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '?dO[iQ$:
{ z<aBGG
nStartPos += fileAccessI.write(b,0,nRead); tJ[yx_mf
//if(nThreadID == 1) l+!!S"=8)~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KBJw7rra
} &5puGnTZ
[P.M>"c\
j#QJ5(#
Utility.log("Thread " + nThreadID + " is over!"); 1O@ qpNm
bDownOver = true; q/U(j&8W{
//nPos = fileAccessI.write (b,0,nRead); n&ZArJ
} 4-;"w;
catch(Exception e){e.printStackTrace ();} {Q],rv|;
} FY_.Vp
} d%_=r." Y
6"fYSn>
K ;\~otR^
//打印回应的头信息 ~_opU(;f
public void logResponseHead(HttpURLConnection con) aX`"V/
{ FsQeyh>
for(int i=1;;i++) {y)O?9q
{ "1O!Ck_n
String header=con.getHeaderFieldKey(i); {$D[l hj
if(header!=null) Cbu/7z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !>QS746S@
Utility.log(header+" : "+con.getHeaderField(header)); fB^h2
else xIu#
break; Py*( %
} M)S(:Il6Xx
} z~&uLu
8G$ %DZ $
m(CW3:|
public void splitterStop() j1{|3#5V
{ d 90
bStop = true; 3FRz&FS:j
} ro|mWP0
)_bc:6Q
'%Og9Bgd+
} MMlryn||1
kQ~2mU
{!!df.h
/* !5,>[^y3
**FileAccess.java |^fubQs;2
*//文件访问(定位，写) <xM$^r)
package NetFox; DfYOGs]@
import java.io.*; 3ARvSz@5
6v8HR}iK
58xaVOhb
public class FileAccessI implements Serializable{ Ku;|Dz/=o
\f| Hk*@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MKVz'-`u
RandomAccessFile oSavedFile; tGt/=~n9
long nPos; iMG)zPj
%smQ`u|
5ncjv@Aa
public FileAccessI() throws IOException *+(t2!yFmE
{ .OhpItn
this("",0); m2c>RCq
} @1+C*
8VG6~>ux'>
^n8ioL\*i
public FileAccessI(String sName,long nPos) throws IOException +m?;,JGt
{ &\<!{Y<'
oSavedFile = new RandomAccessFile(sName,"rw"); MJ5Ymt a
this.nPos = nPos; FY;\1bt<<
oSavedFile.seek(nPos); MTBHFjXO
} k3[rO}>s
u.v 5!G
#,dNhUV#
public synchronized int write(byte[] b,int nStart,int nLen) ?%RAX CK
{ be&5vl
int n = -1; ;+v5li
try{ Vb{5-v ;a
oSavedFile.write(b,nStart,nLen); [zXKS|
n = nLen; VnlgX\$}
} )ph**g
catch(IOException e) L1J \C
{ 1.S7MSpTV
e.printStackTrace (); 6 3TeTGp$
} Xjb 4dip
8yW8F26
-64@}Ts*?
return n; /<[S> ;!kr
} &6]+a4
'?| (QU:)F
feJzX*u
} 9Z?P/ o
M:t!g%
l^`& Tnzv
/* `Fn"%P!
**SiteInfoBean.java { 'A`ram
*/ 'iQ
package NetFox; &d,chb(
~nit~;
`As|MYv
public class SiteInfoBean { &[u>^VO8
:LE0_ .
lKVy{X3]*
private String sSiteURL; //Site's URL j@chSk"K
private String sFilePath; //Saved File's Path R%gkRx[
private String sFileName; //Saved File's Name '8%pEl^
private int nSplitter; //Count of Splited Downloading File +Dvdv<+
2Y~UeJ_\Lq
TtZZjeg+V
public SiteInfoBean() TcB^Sctf
{//nSplitter的缺省值为5 P9d%80(b4
//default value of nSplitter is 5 mM`zA%=
this("","","",5); 0[A4k:
} 2T3TD%
C%c}lv8;^
^3>Qf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MHF31/g\
{ Z|78>0SAt
sSiteURL= sURL; M.DU^-7
sFilePath = sPath; J#k3iE}
sFileName = sName; cL+--$L
this.nSplitter = nSpiltter; Mn)>G36(
Oup5LH!sW
p#14
} bxxazsj^
0P MF)';R
"zN2+X"&
public String getSSiteURL() :ik$@5wp
{ Z)V m,ng
return sSiteURL; yQP!Vt^
} aJ!(c}N~97
+jpaBr-O#
S7|6dwQ&
public void setSSiteURL(String value) xg:r5Z/|)
{ 25bbuhss
sSiteURL = value; l7{]jKJue
} f82$_1s^
*HT)Au"5
@k< e]@r
public String getSFilePath() BIu%A]e"
{ @ve4rc/LI
return sFilePath; Ark+Df/
} $ 12mS
;Avz%2#c`
YwbRzY-#F
public void setSFilePath(String value) d]3c44kkK{
{ Yg @&@S]
sFilePath = value; 6}V)\"u&
} 4=;.<
XwZ~pY ~
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public String getSFileName() ' 91-\en0
{ \>B$x@-wg
return sFileName; t^8ii
} Nu/D$m'PY
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_oV;Y`_
public void setSFileName(String value) z XI [f
{ >"OwdAvX
sFileName = value; 7g* "AEk
} ;8|D4+
sl5y1W/]]
7@[HRr
public int getNSplitter() y_s^dQe
{ <N4)X"s
return nSplitter; *\-R&8
} v?BVUH>#9
J 8!D."'Q0
4t C-msTf
public void setNSplitter(int nCount) A-=B#UF
{ `.MY"g9
nSplitter = nCount; /mi9q
} \2UtT@3|C
} SxX2+|0g`g
S.: m$s
n]G_# ;
/* eT(/D/jan
**Utility.java r Jo8|
*/ 6%jv|\>
package NetFox; |b BA0.yS
r8R]0\
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public class Utility { =up!lg^M
\d"uR@$3mG
Y)Os]<N1
public Utility() h20<X;
{ }\iH~T6
!=)R+g6b
8!R +wy
} sp&s 5aw
A`5/u"]*D
//线程睡眠 WfdM~k\
public static void sleep(int nSecond) ?{)sdJe
{ i 4}4U
try{ WxLmzSz{xD
Thread.sleep(nSecond); RJYB=y8l
} >5O#_?
catch(Exception e) zeC@!,lH
{ Z(|@C(IL0\
e.printStackTrace (); \Zn%r&(
} a/4!zT
} uVSc1MS1
\zdY$3z
//日志 fGwRv%$^
public static void log(String sMsg) O_E\(So
{ 6~oo.6bA
System.err.println(sMsg); Gp l
} 6\+ZTw
jD<fu
M1Frn n
public static void log(int sMsg) lc:dKGF6
{ (plsL
System.err.println(sMsg); E43Gk!/|(
} \*wQ%_N5
} ~ z< &vQ=
#`g..3ey
u|.c?fW'3
/* EgYM][:UU
**TestMethod.java M0B6v}^H
*/ LH:M`\(DL1
package NetFox; tx+KxOt9Y
Dc1tND$X3g
2cB){.E
public class TestMethod { <n+]\a97*
x5X;^.1Fr
2!w5eWl,
public TestMethod() Juhi#&`T
{ ///xx/weblogic60b2_win.exe #1-2)ZO.
try{ _EusY3q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |}FK;@'I6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rnkq.
SiteFileFetch fileFetch = new SiteFileFetch(bean); lI)RaiMr=
fileFetch.start(); pv}k=wqJ1
} t+H=%{z
catch(Exception e){e.printStackTrace ();} dj;Zzt3
ZH1W#dt`[
3iKy>
} \ZOH3`vq
+,g"8&>
^xNs^wC.
public static void main(String[] args) ,A{'lu
{ *GGiSt
new TestMethod(); I,nW~;OV0
} ?*nFz0cs^
} 21LJ3rW_
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