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)); itiSZL,
} |_+l D|'
for(int i=0;i<nEndPos.length-1;i++) :1gpbfW
{ #a tL2(wJ
nEndPos = nStartPos[i+1]; )_o^d>$da
} akCCpnX_d
nEndPos[nEndPos.length-1] = nFileLength; WI&}94w
} .VUnOdI
} eHd7fhW5
-GB,g=Dk
ty%,T.@e
//启动子线程 >+!Ef
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h>!9N dzG
for(int i=0;i<nStartPos.length;i++) UYW'pV
{ e$`hRZ%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WW^+X~Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `P:[.hRu
nStartPos,nEndPos,i); H<?s[MH[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -2 8bJ,
fileSplitterFetch.start(); TK~KM
} Co=Bq{GY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {L.uLr_?e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _nX8f &
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :B7U),T
nEndPos = " + nFileLength); #!#s7^%K&
// fileSplitterFetch[nPos.length-1].start(); @+y,E-YTdV
m] -cRf)9
3r,Kt&2$
//等待子线程结束 V 7ZGT
//int count = 0; JZ:yPvJ
//是否结束while循环 GWWaH+F[h
boolean breakWhile = false; H(M{hfa|
m"'`$/_
+~y>22Zfg
while(!bStop) qss)5a/x.
{ $ye>;Ek
write_nPos(); x_C0=Q|K3
Utility.sleep(500); d:#tN4y7(
breakWhile = true; cJTwgm?
tL<.B
w $`w
for(int i=0;i<nStartPos.length;i++) ^7=7V0>,:
{ '^$+G0jv
if(!fileSplitterFetch.bDownOver) @^ m0>H
{ fd>&RbUp
breakWhile = false; DrxQ(yo}
break; Q#K10*-O6
} @A*>lUo
} '4Qsl~[Eh
if(breakWhile) AR$SQ_4
break; Z`ww[Tbv~
k{UeY[,jb
b&LAk-}[
//count++; O(D2F$VlL
//if(count>4) BIe:7cR%
// siteStop(); d/~g3n>|
} u3tT=5.D
U)aftH *Pk
.|s,':hA
System.err.println("文件下载结束！"); vP? T
} ~gNFcJuy
catch(Exception e){e.printStackTrace ();} {0-rnSjC
} x)eoz2E1
MPw?HpM
S3E5^n\\
//获得文件长度 GCfVH?Vx
public long getFileSize() R-1MD
{ mF jM6pmo
int nFileLength = -1; AS;qJ)JfzQ
try{ @';.$
URL url = new URL(siteInfoBean.getSSiteURL()); Aq3\Q>klH)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Vgpv#&Cfx
httpConnection.setRequestProperty("User-Agent","NetFox"); g0B%3v
G|8>Q3D
QgQ$>
int responseCode=httpConnection.getResponseCode(); Np ru
if(responseCode>=400) >'.: Acn
{ v7`{6Pf_$
processErrorCode(responseCode); 4i+%~X@p
return -2; //-2 represent access is error N>]J$[j
} #k`gm)|
8?YeaMIBB
q(~|roKA(
String sHeader; jIH^
uI%7jA~@
BHZhdm@),
for(int i=1;;i++) +"=ydF.9
{ lCl5#L9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V{A`?Jl6{
//Utility.log(in.readLine()); EUQtl_h/H
sHeader=httpConnection.getHeaderFieldKey(i); d)acWF\
if(sHeader!=null) lmD[Cn
{ & 0WQF
if(sHeader.equals("Content-Length")) V'MY+#
{ yBIX<P)vE'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yTZo4c"
break; cF8X
} Q[K)Yd
} K:~tZ
else mZPvG
break; j0a=v}j3
} a }*i [
} rPGj+wL5-
catch(IOException e){e.printStackTrace ();} /@\R
catch(Exception e){e.printStackTrace ();} BzO,(bd!PI
RwOOe7mv
SPt/$uYJ
Utility.log(nFileLength); |g!d[ct]
N2duhI6
u#Jr_ze
return nFileLength; 32%Fdz1S
} *h3iAcM8
K5BL4N
#d-zH:uq
//保存下载信息（文件指针位置） eNVuw:Q+
private void write_nPos() u'>94Gm}
{ A>2_I)
try{ NMf#0Nz-
output = new DataOutputStream(new FileOutputStream(tmpFile)); g=@d!]Z~[
output.writeInt(nStartPos.length); AovBKB $
for(int i=0;i<nStartPos.length;i++) zp<B,Ls
{ 1 ptyiy
// output.writeLong(nPos); [0]A-#J
output.writeLong(fileSplitterFetch.nStartPos); ZILJXX4
output.writeLong(fileSplitterFetch.nEndPos); 5\#I4\
} ~QxW^DGa7]
output.close(); B%MdJD>
} pq&[cA_w
catch(IOException e){e.printStackTrace ();} K%x]:|,>M
catch(Exception e){e.printStackTrace ();} IM/xBP
} x-X~'p'f
BI%XF 9{
vB{iw}Hi!
//读取保存的下载信息（文件指针位置） NlKVl~_ C
private void read_nPos() )OxcCV?5Z
{ rVl 8?uy
try{ fi%i 2Wy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3Ke6lV)uq
int nCount = input.readInt(); m|{^T/kIbQ
nStartPos = new long[nCount]; #5z0~Mg-X
nEndPos = new long[nCount]; GJrmK
for(int i=0;i<nStartPos.length;i++) L+<h5>6
{ 2Ki_d
nStartPos = input.readLong(); {5<fvMO!6
nEndPos = input.readLong(); >V27#L2:J
} bp=r]nO
input.close(); 4R\jZ@D
} jHn7H)F8
catch(IOException e){e.printStackTrace ();} %]DA4W
catch(Exception e){e.printStackTrace ();} 83t/\x,Q
} c3g`k"3*`
?Y,^Moc:
'xxM0Kn`
private void processErrorCode(int nErrorCode) Z_m<x!
{ YI,t{Wy
System.err.println("Error Code : " + nErrorCode); 62zu;p9m
} m}s.a.x
Rk3 bZvj3
AguE)I&m
//停止文件下载 /[\g8U{5B}
public void siteStop() 1(IZ,*i
{ P@vUQ
bStop = true; L-D4>+
for(int i=0;i<nStartPos.length;i++) ob;|%_
fileSplitterFetch.splitterStop(); z06,$OYz
/YHO"4Z
~nfOV*
} w3);ZQ|
} $m2#oI'D
//负责部分文件的抓取 _ s3d$C?B
**FileSplitterFetch.java b&&l
*/ 72Y6gcg
package NetFox; NGl 8*Af
3,{eH6,O7M
,S=[#
import java.io.*; rD SYR\cg
import java.net.*; 0r1GGEW`s
9 $$uk'}w!
\+O.vRc"M
public class FileSplitterFetch extends Thread { Z6i~Dy3
PD.$a-t
0ck3II
String sURL; //File URL rVNx2
long nStartPos; //File Snippet Start Position gI;"PkN
long nEndPos; //File Snippet End Position $a*7Q~4
int nThreadID; //Thread's ID 7N[".V]c
boolean bDownOver = false; //Downing is over NOXP}M
boolean bStop = false; //Stop identical lsOv#X-bE
FileAccessI fileAccessI = null; //File Access interface PD0&ep1h7G
bN zb#P#hP
D~ Y6%9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n*wQgC'vw
{ ra T9
this.sURL = sURL; m]>zdP+
this.nStartPos = nStart; e!*]y&W
this.nEndPos = nEnd; QTi@yT:
nThreadID = id; 9Sxr9FLW~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6Qt(Yu*s
} [_(J8~va
@NRN#~S,_]
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public void run() |du%c`wl
{ 018SFle
while(nStartPos < nEndPos && !bStop) WT<}3(S'?
{ m.m6.
&`l\Q\_[@
c.IUqin
try{ 6-_g1vq
URL url = new URL(sURL); fc*>ky.v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5+M,X kg
httpConnection.setRequestProperty("User-Agent","NetFox"); `5?0yXK
String sProperty = "bytes="+nStartPos+"-"; `z(o01y
httpConnection.setRequestProperty("RANGE",sProperty); CsA(oX
Utility.log(sProperty); vu*e*b$}
2lpPN[~d
))|d~m
InputStream input = httpConnection.getInputStream(); T:@6(_Z
//logResponseHead(httpConnection); >^jBE''
t[`LG)
Gg'!(]v
byte[] b = new byte[1024]; .T9$O]:o
int nRead; m1pA]}Y/5o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @-dGZ5
{ 9m)$^U>oz
nStartPos += fileAccessI.write(b,0,nRead); Hp=BnN
//if(nThreadID == 1) ay7\Ae]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *gwlW/%Fz
} }S uj=oFp
8j#S+=l>
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Utility.log("Thread " + nThreadID + " is over!"); V ,p~,rC
bDownOver = true; ^Qx?)(@
//nPos = fileAccessI.write (b,0,nRead); U3a2wK
} q8d](MaX
catch(Exception e){e.printStackTrace ();} Ow/,pC >V
} +fXwbZ?p
} f-|?He4O]
KBB)xez8
b_~XTWP$l
//打印回应的头信息 `&D#P%
public void logResponseHead(HttpURLConnection con) RBrb7D{
{ =Q(J!f
for(int i=1;;i++) 940:NOgm
{ DH?n~qKpC
String header=con.getHeaderFieldKey(i); _gqqPny4$
if(header!=null) c1k[)O~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p*Q-o
Utility.log(header+" : "+con.getHeaderField(header)); (a_bU5)
else D0jV}oz
break; $\NqD:fgb
} e' l9
} 7(+4^
'Eur[~k
9-T<gYl
public void splitterStop() >XgJo7u
{ e n~m)r3&
bStop = true; Sxq@W8W
} ck{S
}?,?2U,8:
Q^f{H.
} 4}m9,
$~b6H]"9
i`gM> q&
/* <4Gy~?
**FileAccess.java Nf)YG!
*//文件访问(定位，写) l%EvXdZuOy
package NetFox; vWoppt
import java.io.*; @.-S(MNR
X3}eq|r9
L=#NUNiXr
public class FileAccessI implements Serializable{ v'S]g^
&K0b3AWc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lk 1\|Q I
RandomAccessFile oSavedFile; 53:~a
long nPos; <8b1OdA
(U&
U)8yd,qG[%
public FileAccessI() throws IOException .m]}Ba}J$
{ pZ>yBY?R8>
this("",0); [o<hQ`&
} VH]}{i"`
yIKpyyC9H
_!o8s%9be
public FileAccessI(String sName,long nPos) throws IOException $!*>5".A
{ /3aW 0/^o
oSavedFile = new RandomAccessFile(sName,"rw"); @KL&vm(F$
this.nPos = nPos; F^gTID
oSavedFile.seek(nPos); BjfVNF;hk:
} I/njyV)H
u"qVT9C$=
+ kMj|()>\
public synchronized int write(byte[] b,int nStart,int nLen) :u,.(INB
{ D:Q#%wJ
int n = -1; 8Ij<t{Lps
try{ QZ&(e2z
oSavedFile.write(b,nStart,nLen); [cnuK
n = nLen; o>8~rtl
} rByth,|
catch(IOException e) vIJ5iLF
{ JhFn"(O
e.printStackTrace (); -Rw3[4>@O"
} '*y(F*7+
G~1;_'
!-OZ/^l|O`
return n; lq:q0>vyI
} jM$bWtq2
qt@/
+4%~.,<_to
} L-w3A:jk
!s-A`} s+
{KHI(*r;
/* M3-lL;!n
**SiteInfoBean.java ,A{Bx`o?
*/ DKt98;
package NetFox; C<J*C0vQO
8S#$'2sT
X "7CN Td
public class SiteInfoBean { B`-uZ9k
Sn*s@RE\s
q?7''xk7
private String sSiteURL; //Site's URL cIwX sx
private String sFilePath; //Saved File's Path w317]-n
private String sFileName; //Saved File's Name rQ*w3F?:
private int nSplitter; //Count of Splited Downloading File FXBmatBck
"v:k5a(
(O J/u)W^
public SiteInfoBean() O6Py
{//nSplitter的缺省值为5 5&s6(?,Eu
//default value of nSplitter is 5 @ 3=pFYW)
this("","","",5); F[}#7}xjA
} `$f`55e
"]=OR>
uNn1qV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :o^ioX.J
{ X&zGgP/
sSiteURL= sURL; +zMhA p
sFilePath = sPath; 8~O#@hB~3
sFileName = sName; E'\gd7t ;
this.nSplitter = nSpiltter; w0g@ <( 3
@]n8*n
GG>53}7{
} ^)9/Wz _x
h/tCve3Z
G06;x
public String getSSiteURL() F\N0<o
{ 7#C$}1XJ1
return sSiteURL; \L(jNN0_R
} o?}dHTk7
t,%m-dU
c-hc.i}!
public void setSSiteURL(String value) 8)8~c@
{ =Lkn
sSiteURL = value; MPUyu(-%{
} enPtW
-E\G3/*51
qe&|6M!
public String getSFilePath() 4C?{p%3c
{ PJZ;wqTD_
return sFilePath; l\ dPfJ
} %BC%fVdP
E?+~S M1~
PWS8Dpb
public void setSFilePath(String value) H'3 pHb
{ S=P}Jpq?Y;
sFilePath = value; z+.G>0M
} VL*5
Jy:*GW6
%6(\Ki6I
public String getSFileName() =k<b* 8
{ K7C <}y
return sFileName; k+{~#@
} -I{op wd
JYNnzgd
Y&bYaq
public void setSFileName(String value) gWHY7rv
{ =T3{!\tH
sFileName = value; iWeUsS%zpV
} 5)f 'wVe
LNJKf6:
huv|l6
public int getNSplitter() a"P & 9c
{ Fw[1Aa#
return nSplitter; hvTc( 0;mB
} ,9G'1%z,
xytWE:=
H9jlp.F
public void setNSplitter(int nCount) {G=>WAXo
{ 'KmM%tN
nSplitter = nCount; }2LG9B%
} fV4eGIR&
} P\ P=1NM
=?Ry,^=b
=55)|$hgD
/* ])y)]H#{
**Utility.java ^) s6`:
*/ vrmMEWPV
package NetFox; gAvNm[=wD2
P}AwE,&Q
JGq9RB]D$
public class Utility { @8J*vY =e
|goBIp[
Ow?~+) 4
public Utility() a?Fz&BE
{ 1y[~xxgE
R|Bi%q|4P
Z .`+IN(>E
} Yw=@*CK'
o&q:b9T
//线程睡眠 MA tF,
public static void sleep(int nSecond) wIRU!lIF9
{ dW/(#KP/+
try{ ?_{{iil
Thread.sleep(nSecond); TQt[he$O
} d^?e*USh
catch(Exception e) |oeg'T
{ UBv#z&@[
e.printStackTrace (); H '5zl^8I
} -"yma_
} -GL.8"c[
b6e2a/x
//日志 HHyN\
public static void log(String sMsg) <AVWT+,
{ }6u}?>S
System.err.println(sMsg); [EPRBK`=
} 3J4OkwqD
uAYDX<Ja9
0Q>
public static void log(int sMsg) lnl>!z
{ 8}oe))b
System.err.println(sMsg); -{L 7%j|R
} r8y,$Mv<)0
} p&(z'd
mtFC H
meB9:w[m
/* %j2:W\g:
**TestMethod.java }cW8B"_"
*/ hHEn
package NetFox; \o,et9zDJ3
aAu%QRq
(8S+-k?
public class TestMethod { 4nd)*0{f
\HoVS
N}z]OvnZH
public TestMethod() N^`S'FVA
{ ///xx/weblogic60b2_win.exe 6a]Qg99\
try{ j*VYUM@y1\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IL&R&8'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ey&A\
SiteFileFetch fileFetch = new SiteFileFetch(bean); gvjy'Rm
fileFetch.start(); iF##3H$c
} =v!8i
catch(Exception e){e.printStackTrace ();} '&AeOn
V-%jSe<
o9D#d\G
} bA"*^"^
7'.6/U
#)DDQ?D
public static void main(String[] args) A9HgABhax
{ (ia+N/$u
new TestMethod(); eZpi+BRS6
} 0*OK]`9
} coXm*X>z
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