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)); Q0TKM>
} 6`)Ss5jzk
for(int i=0;i<nEndPos.length-1;i++) NqN9
{ 83:qIfF
nEndPos = nStartPos[i+1]; \3cg\Q+~
} OLDEB.@
nEndPos[nEndPos.length-1] = nFileLength; =5M '+>
} 1i$OcN?x%
} 6hqqZ
T!Uf PfEI
%* @hS`
//启动子线程 p;{w0uld"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6X$iTJ[\x
for(int i=0;i<nStartPos.length;i++) fU4{4M+9"
{ \V9);KAOj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -257g;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3$kElq[
nStartPos,nEndPos,i); MZSyu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZHc;8|}
fileSplitterFetch.start(); *q(HW
} DZX4c2J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5$ rV0X,O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |(R[5q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZRCUM"R_
nEndPos = " + nFileLength); f8L3+u
// fileSplitterFetch[nPos.length-1].start(); zuBfkW95+
^r~R]stE^
i<{/r-w=E
//等待子线程结束 Z/I`XPmk
//int count = 0; A>}]=Ii/
//是否结束while循环 bqUQadDB
boolean breakWhile = false; LP}YHW/
3hNb ?
OY(znVHU
while(!bStop) K.\-
{ -!ERe@k(
write_nPos(); JT 5+d ,
Utility.sleep(500); , -S n
breakWhile = true; n/GJ&qLi:g
%Lgfi
s B!2't
for(int i=0;i<nStartPos.length;i++) `jCq`-.
{ w3peG^4D_
if(!fileSplitterFetch.bDownOver) 2N_9S?a3sK
{ |}K7Q
breakWhile = false; `H\NJ,
break; DZ0\pp?S
} Jf8AKj3
} Hxd^oE
if(breakWhile) 8__C T
break; 0qD.OF)8
^->vUf7PX
zGE{Z A
//count++; ?C9>bKo*2H
//if(count>4) iMOf];O)
// siteStop(); TZk.h8
} lpeo^Y}N
g3,F+
q"pnFK9/L
System.err.println("文件下载结束！"); x$tzq+N
} g].hL
catch(Exception e){e.printStackTrace ();} =;A~$[g
} ~b{j`T
u+uu?.bM
Zu%oIk
//获得文件长度 @?"t&h
public long getFileSize() Y{ 2xokJ N
{ 8rsv8OO
int nFileLength = -1; X+XbIbUuL
try{ nzORG
URL url = new URL(siteInfoBean.getSSiteURL()); ecy41y'~:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &,@wLy^T
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Ai$1'*p
J'y*>dW
quw:4W>
int responseCode=httpConnection.getResponseCode(); Li\BRlebR{
if(responseCode>=400) _a,XL<9I
{ >~^##bIb
processErrorCode(responseCode); W4(O2RU
return -2; //-2 represent access is error [u2)kH$
} 6 _\j_$
ihdtq
3$ 1 z
String sHeader; '$n#~/#}
>jDx-H.N
;M Z@2CO
for(int i=1;;i++) [M6/?4\
{ 8?7:sfc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iP~dH/B|v
//Utility.log(in.readLine()); 15FGlO<<
sHeader=httpConnection.getHeaderFieldKey(i); da&f0m U
if(sHeader!=null) _Uz}z#jt
{ CVFsp>+
if(sHeader.equals("Content-Length")) T"m(V/L$W
{ F I\V6\B/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L)ry!BuHI
break; #FV(a~
} o<-+y\J8K
} v{2Vg
else ^~dvA)bH
break; %U)M?UNjw
} i@ avm7
} "i_}\p.,X
catch(IOException e){e.printStackTrace ();} 8h2!8'
catch(Exception e){e.printStackTrace ();} 5K*-)F ]
wfrWpz=FO
-m~[z
Utility.log(nFileLength); e?D,=A4mV"
D0&{iZ(
z[wk-a+w
return nFileLength; (8(z42
} Eqva] 4
dj76YK
6gfdXVN5
//保存下载信息（文件指针位置） +<ey Iw
private void write_nPos() Up$vBE8i]
{ X7]vXo*
try{ <!vAqqljt
output = new DataOutputStream(new FileOutputStream(tmpFile)); Uq6..<#
output.writeInt(nStartPos.length); t%AW0#TZ
for(int i=0;i<nStartPos.length;i++) *7I=vro
{ Ucnit^,
// output.writeLong(nPos); !Jj=H()}
output.writeLong(fileSplitterFetch.nStartPos); YtrMJ"
output.writeLong(fileSplitterFetch.nEndPos); z {J1pH_X
} a;Y9wn
output.close(); $*H>n!&
} LHWh-h(s
catch(IOException e){e.printStackTrace ();} u[oYVpe)IG
catch(Exception e){e.printStackTrace ();} &7X0 ;<
} +:[dviyPt
ca_8S8lv
UmU=3et<Wj
//读取保存的下载信息（文件指针位置） jL)aU> kN
private void read_nPos() 5\tYs=>b<
{ yXw xq(32
try{ U<NpDjc"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g5to0
int nCount = input.readInt(); OX4+1@$tk
nStartPos = new long[nCount]; EQ>bwEG
nEndPos = new long[nCount]; .-N9\GlJ,d
for(int i=0;i<nStartPos.length;i++) *#;rp~
{ um&e.V)N
nStartPos = input.readLong(); +-#| M|a
nEndPos = input.readLong(); }h>e=<
} w|PZSOJ
input.close(); 4f"a/(>*
} ]IJ.}
catch(IOException e){e.printStackTrace ();} l(zkMR$b8
catch(Exception e){e.printStackTrace ();} hk&p+NV!
} nx,67u/Pb
N_r*Ig
>|7&hj$
private void processErrorCode(int nErrorCode) zT~ GBC-IX
{ bah5 f
System.err.println("Error Code : " + nErrorCode); Pwz^{*u]
} VPg`vI$(X
i4!n Oyk
^B?koU l^
//停止文件下载 Af0E_
public void siteStop() a@,tf'Sr
{ Zk}e?Grc
bStop = true; ?#D@e5Wf
for(int i=0;i<nStartPos.length;i++) 2#1FI0,Pa*
fileSplitterFetch.splitterStop(); $X~=M_W
Qq]UEI `Go
fC%;|V'Nd
} xyz-T1ib
} EGGy0ly
//负责部分文件的抓取 XW]|Mv[M
**FileSplitterFetch.java %_SE$>v^
*/ ?-\KVha
package NetFox; 8N-~.p
kC9A
`Xmpm4 ]
import java.io.*; G68N@g
import java.net.*; h/(9AO}t
3[aJ=5
i$:CGUb
public class FileSplitterFetch extends Thread { x_Ais&Gc
Punbw\9!d,
HNjkRl)QR
String sURL; //File URL 2 >xV&
long nStartPos; //File Snippet Start Position Gh|1%g"gm
long nEndPos; //File Snippet End Position b<.+WkO
int nThreadID; //Thread's ID |Be.r{l
boolean bDownOver = false; //Downing is over -R7f/a8
boolean bStop = false; //Stop identical R?|_`@@A
FileAccessI fileAccessI = null; //File Access interface N}FG%a
$X*$,CCIB
//Tr=!TQu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bdbw!zRR$
{ JBUJc
this.sURL = sURL; " 31C8
this.nStartPos = nStart; <O\z`aA'q
this.nEndPos = nEnd; FT(EH
nThreadID = id; *%)L?*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vlj|[joXw
} 4?yc/F=kI
7 cIVK}&
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public void run() ,CM$A}7[
{ Ha C?,
while(nStartPos < nEndPos && !bStop) B~PF<8h5
{ "F[VqqD
=C3l:pGMB;
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try{ 6gR=e+
URL url = new URL(sURL); [[s k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qn*c<:
httpConnection.setRequestProperty("User-Agent","NetFox"); T.`%1S
String sProperty = "bytes="+nStartPos+"-"; U5Ho? `<
httpConnection.setRequestProperty("RANGE",sProperty); >MP PYVn7
Utility.log(sProperty); Ugdm"
06Hn:IT18
%] #; ~I%
InputStream input = httpConnection.getInputStream(); Bxa],inuZ
//logResponseHead(httpConnection); 09%eaoW
nW drVT$
ZA9']u%EJ
byte[] b = new byte[1024]; BgpJ;D+N4
int nRead; giu~"#0/F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U.^)|IHW
{ }lxvXVc{I
nStartPos += fileAccessI.write(b,0,nRead); Bnxzy n
//if(nThreadID == 1) ReK@~#hLY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;D^)^~7dh
} 'Ux_X:,:;
?Y hua9
3mm`8!R
Utility.log("Thread " + nThreadID + " is over!"); IYQYW.`ly
bDownOver = true; +qz)KtJS
//nPos = fileAccessI.write (b,0,nRead); 9lD,aOb
} l[fNftT-
catch(Exception e){e.printStackTrace ();} q]r!5&Z
} QKP9*dz
} n~)Y%xe[U
=V,'f
@`_j't,
//打印回应的头信息 N0qC/da1
public void logResponseHead(HttpURLConnection con) U/iAP W4U
{ 6=@n b3D%
for(int i=1;;i++) Uv+pdRXn
{ %#]T.g
String header=con.getHeaderFieldKey(i); Qs?+vk?*h
if(header!=null) s?6 7@\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q[b({Vj;tG
Utility.log(header+" : "+con.getHeaderField(header)); h3)KT+7.
else q!H3JL
break; #/tdZ0
} fFd9D=EW.
} Bs1-UI}+
=)zq%d?i;
R/Y/#X^b
public void splitterStop() CMg83
{ rvmI 8
bStop = true; KOmP-q=6
} ,X$Avdc2
`Eu(r]:W
Gz6GU.IyQy
} {//F>5~[
8uGPyH
6szkE{-/?
/* LNN:GD)>
**FileAccess.java oOL3O@)w>
*//文件访问(定位，写) Z~,.l
package NetFox; )R +o8C
import java.io.*; $3[cBX.=
#y*=UV|h
eB\r/B]
public class FileAccessI implements Serializable{ \Zh)oUHd
__V]HcP;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^2AF:(E
RandomAccessFile oSavedFile; D}061~zb$
long nPos; eFnsf}(Iy
n% `r
={b ]
public FileAccessI() throws IOException ,|#>X>^FQQ
{ R`**!ku
this("",0); |O)deiJRy
} g_>ZE
R|CY4G j
d=#p w*w
public FileAccessI(String sName,long nPos) throws IOException ^i8I 1@ =
{ #w*pWD^
oSavedFile = new RandomAccessFile(sName,"rw"); lQsQRp
this.nPos = nPos; {.lF~cOu
oSavedFile.seek(nPos); E&>,B81
} ommKf[h%i
!U#++Zig%
x7@WWFF>
public synchronized int write(byte[] b,int nStart,int nLen) r~}}o o4K
{ )*A,L%
int n = -1; ZM vTDH!
try{ 6|KX8\,A@
oSavedFile.write(b,nStart,nLen); TN %"RL
n = nLen; bSr 'ji
} 6oP{P_Pxi
catch(IOException e) h3kHI?jMWG
{ tRy D@}
e.printStackTrace (); FR}H$R7#
} .?p}:
2&Byq
bNROXiX
return n; ,OKM\N,
} yo*iv+l
/,Rca1W
}K>HS\e
} ~t:b<'/
Qsntf.fT
P*PL6UQ
/* 99!{[gOv
**SiteInfoBean.java 3] qlz?5
*/ O&,O:b:@
package NetFox; xploFw~
s3M84wz
O$Vm#|$sq
public class SiteInfoBean { gFT~\3jp=
t%U[\\ic
A(n=kx
private String sSiteURL; //Site's URL m"G N^V7
private String sFilePath; //Saved File's Path "k-ov9yK
private String sFileName; //Saved File's Name \B2d(=~4
private int nSplitter; //Count of Splited Downloading File }iSakq'
5b#6 Y
*|HZ&}
public SiteInfoBean() j/9QV
{//nSplitter的缺省值为5 KupMndK
//default value of nSplitter is 5 CjQ"oQw
this("","","",5); 5FSv"=
} v1C.\fL
Tq84Fn!HJ>
T'M66kg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q==v!"Gi|
{ jAK{<7v4U
sSiteURL= sURL; #tZf>zrs
sFilePath = sPath; I/Jp,~JT*
sFileName = sName; ,Us2UEWNv
this.nSplitter = nSpiltter; {TncqA
c,q"}nE8w
d_C4B
} t;!]z-Y>
h)_Gxe"x
sJb)HQ,7x
public String getSSiteURL() DAnb.0
{ [tqO}D
return sSiteURL; jRG\C=&(x
} fT3*>^Uv
v'Vt .m&9&
+oy&OKCa
public void setSSiteURL(String value) |WAD $3
{ V+qJrZ,i
sSiteURL = value; g6g$nY@Jm
} hoR=%pC*
3l%,D: ?
{KDgK
public String getSFilePath() 9U)t@b
{ ahtYSz_FM
return sFilePath; V-_/(xt*
} Hl3)R*&'J
WE[m@K[CR
UQ3@@:L_
public void setSFilePath(String value) kwHqvO!G
{ VkpHzr[k
sFilePath = value; k\pDJ7wF^
} Mi}I0yhVm
rQEi/
:wU_-{>>2
public String getSFileName() ESMG<vW&f
{ *J_iXu|
return sFileName; VD24X
} poD\C;o"
,?k%jcR
_(6`{PWY
public void setSFileName(String value) ]G0dS Fh{j
{ '_qQrP#
sFileName = value; rKzlK 'U
} JzMZB"Z?
pDq#8*q+v
#9`rXEz
public int getNSplitter() (`6%og#8
{ B:-U`CHHQ
return nSplitter; W7L+8LU;
} 4TUtY:
~o@\ n
:)p)=c8%
public void setNSplitter(int nCount) JoCA{Fa}
{ ,;.B4
nSplitter = nCount; EqnpMHF
} {pDTy7!Hs
} UP;Q=t
ivzAlwP
v**z$5x9
/* kG1;]1tT#
**Utility.java [q-;/ed
*/ dTN$y\
package NetFox; *bA+]&dj\
@P:R~m2
4.|-m.a
public class Utility { S Pn8\2Cj
=4tO0
c^=R8y-N
public Utility() :N@U[Wx0A
{ %bP~wl~
`c"4PU^
k6Ihc?HL
} gYatsFyL
hH%,!tSx
//线程睡眠 -J,Q;tj
public static void sleep(int nSecond) B0oxCc/'sZ
{ $PSY:Zz
try{ Q.,DZp
Thread.sleep(nSecond); |gnAqkW0
} u#`+[AC`
catch(Exception e) ljPq2v ]
{ 6&89~W{
e.printStackTrace (); yl-fbYH
} x;]x_fz
} &%^K,Q"
XOrcygb2
//日志 akT|Y4KxD
public static void log(String sMsg) s^w\zzYb
{ =fl%8"%N&
System.err.println(sMsg); SLkuT`*
} sVu k
v f`9*xF
./l|8o
public static void log(int sMsg) .APVjqG
{ }A|))Ao|
System.err.println(sMsg); Wo{K}
} I:#Ok+
} :pwa{P
|;P^clS3
8xgJSk
/* q]^,vei
**TestMethod.java pOMgEEhfS
*/ x;u~NKy
package NetFox; 4O!E|/`wO
F>N+<Z
s~^*+kq
public class TestMethod { td >,TW=A*
.Gh%p`<
lop uf/U0
public TestMethod() B{p4G`$i1
{ ///xx/weblogic60b2_win.exe yRC3 .[
try{ }W$8M>l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QY@u}&m%o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ep mJWbU
SiteFileFetch fileFetch = new SiteFileFetch(bean); cC%j!8!
fileFetch.start(); R4b-M0H
} 3jF|Ic
catch(Exception e){e.printStackTrace ();} -#aZF2z
'M8aW!~
EJLQ&oH[
} vU!8`x)
Z:@6Lv?CN
_gW{gLYyJ
public static void main(String[] args) )lh8 k{
{ QH~Jy*\+PX
new TestMethod(); :a.0hes
} 3B{[%#vO
} ?,07;>&
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