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)); 0p!>JQ]m
} #a8B/-
for(int i=0;i<nEndPos.length-1;i++) :1bWVM)
{ VeQg-#&I
nEndPos = nStartPos[i+1]; !74S
} :dQ B R
nEndPos[nEndPos.length-1] = nFileLength; 8;+B*+%@n
} +yD`3` E
} $NZ-{dY{
8Y7Q+p|O
m~-K[+ya`D
//启动子线程 +w{*Xk)4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m4l& eEp
for(int i=0;i<nStartPos.length;i++) &b%zQ4%d-`
{ Z*= $8e@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lja>8m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j+uLV{~g6
nStartPos,nEndPos,i); yU-e3O7L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [VsKa\9u
fileSplitterFetch.start(); ~ijVmWNk
} B=^)Ub5'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hUp.tK:X7o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !FElW`F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [k;\SXDZo
nEndPos = " + nFileLength); w"cZHm
// fileSplitterFetch[nPos.length-1].start(); IV\'e}
%~2YE
U$WxHYo
//等待子线程结束 |6K+E6H
//int count = 0; @c;|G$E@3
//是否结束while循环 J:V6
boolean breakWhile = false; 5',8 ziJQ
)W;o<:x3
4;0lvDD
while(!bStop) iiS-9>]/
{ ]);%wy{Ho
write_nPos(); Hn%xDJ'
Utility.sleep(500); (2^gVz=j
breakWhile = true; 2[O&NdP\Zk
~l]ve,W[
{pnS Q
for(int i=0;i<nStartPos.length;i++) 3@M|m<_R$
{ { + Zd*)M[
if(!fileSplitterFetch.bDownOver) Pa V@aM~3
{ `\#B18eU
breakWhile = false; `OXpU,Z 6U
break; B1>/5hV}
} 8TLgNQP
} g" .are'7
if(breakWhile) IDB+%xl#S
break; 2ZG5<"DQ"
[f1 (`<
|yQZt/*SOZ
//count++; I+[>I=ewa
//if(count>4) ->y J5smtY
// siteStop(); V@cM|(
} $m].8?
;>?rP88t
{MCi<7j<?
System.err.println("文件下载结束！"); +zaA,e?\
} w35J.zn
catch(Exception e){e.printStackTrace ();} ifUGY[L
} i+S) K
Jrti cK$
QxVq^H
//获得文件长度 QLEKsX7p>
public long getFileSize() BGD8w2
{ [<g?WPCcC
int nFileLength = -1; Mn2QZp4
try{ s;S?;(QI
URL url = new URL(siteInfoBean.getSSiteURL()); 1 u| wMO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %|g>%D3Z?
httpConnection.setRequestProperty("User-Agent","NetFox"); #h8Sq~0
v/68*,z[
zr+zhpp
int responseCode=httpConnection.getResponseCode(); q)S^P>
if(responseCode>=400) *W0y: 3dB3
{ l_P-j96WD
processErrorCode(responseCode); G-xDN59K
return -2; //-2 represent access is error Y^8C)p9r
} e;Ti&o}
a(kg/s
aY'C%^h]
String sHeader; #{?PbBE}
>/kcdWl
Ljxz.2LGr
for(int i=1;;i++) u37'~&o{U
{ 4C<jdv_J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &]e'KdXF
//Utility.log(in.readLine()); "?ucO4d
sHeader=httpConnection.getHeaderFieldKey(i); !;i`PPRwk
if(sHeader!=null) Ox&P}P0f
{ 8+a4>8[M
if(sHeader.equals("Content-Length")) s \;"X
{ \`oT#|0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0B@SN)<kH
break; /y _O4
} %{AO+u2i
} 01r 8$+
else 8$85^Of
break; zVXC1u9B
} Ir`eL
} /<@SFF.
catch(IOException e){e.printStackTrace ();} *c~T@m~DR
catch(Exception e){e.printStackTrace ();} a`&f
{ /K.3
WN{ 9
Utility.log(nFileLength); cik!GA
"!Uqcay-
x(hE3S#+
return nFileLength; YQ+tDZY8`
} iVp,e
z.$4!$q
,k{#S?:b
//保存下载信息（文件指针位置） (i34sqV$m
private void write_nPos() F~%]6^$w
{ u [m
try{ ,uo'c_f(e
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?EJD?,}
output.writeInt(nStartPos.length); ??PC k1X
for(int i=0;i<nStartPos.length;i++) dx;Ysn0-
{ IE;~?W"
// output.writeLong(nPos); _hRcc"MS`
output.writeLong(fileSplitterFetch.nStartPos); f!oT65Vmi
output.writeLong(fileSplitterFetch.nEndPos); %+8F'&X
} P_?gq>E8
output.close(); ';TT4$(m
} b8V~S'6VqO
catch(IOException e){e.printStackTrace ();} tZ} v%3
catch(Exception e){e.printStackTrace ();} Gb8D[1=u=
} c_-drS
jNLw=
@y='^DQ*
//读取保存的下载信息（文件指针位置） >TOu|r
private void read_nPos() UUzYbuS>&l
{ 4]h =yc R
try{ D2](da:]8)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $nb[G$
int nCount = input.readInt(); (8Bk;bd
nStartPos = new long[nCount]; HG+%HUO$
nEndPos = new long[nCount]; "OQ^U_
for(int i=0;i<nStartPos.length;i++) +Vm}E0Ov
{ rG4';V^q
nStartPos = input.readLong(); *pAV2V(!23
nEndPos = input.readLong(); * mOo@+89
} @\|_
input.close(); |+iws8xK?
} k.uMp<)D
catch(IOException e){e.printStackTrace ();} JHz [7
catch(Exception e){e.printStackTrace ();} S/D^
} @!`Xl*l
k p<OJy
(iL|Sq&}b
private void processErrorCode(int nErrorCode) Z @^9PQG$
{ Tav*+
System.err.println("Error Code : " + nErrorCode); :?/cPg'D
} l-SAC3qhG
a"FCZ.O1
QA<Jr5Ys
//停止文件下载 GM3f-\/
public void siteStop() f>W-
{ 5[A@gw0u
bStop = true; ~ vJ,`?
for(int i=0;i<nStartPos.length;i++) W7 Cc
fileSplitterFetch.splitterStop(); Zy o[(`y
~xD={9BL
5qr'.m
} b]x4o#t
} W0l,cOOZJ
//负责部分文件的抓取 WN01h=1J_
**FileSplitterFetch.java %KmiH ;U
*/ u/M+u;
package NetFox; pL{U `5S
qMLD)rL
dR"@`
import java.io.*; d5oIH
import java.net.*; '=Rs/EDME
Qk,I^1w?7
ch0{+g&
public class FileSplitterFetch extends Thread { t0IEaj75c
<-[wd.M_
pov)Z):}G<
String sURL; //File URL gLy&esJl1
long nStartPos; //File Snippet Start Position m06ALD_
long nEndPos; //File Snippet End Position {buo^kgj`]
int nThreadID; //Thread's ID @}@Z8$G^
boolean bDownOver = false; //Downing is over O*0l+mop
boolean bStop = false; //Stop identical YhDtUt}?
FileAccessI fileAccessI = null; //File Access interface 8=gjY\Dp
M+w=O!dq
ptU\[Tq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *T5!{
{ w]]8dz
this.sURL = sURL; UPG9)aF
this.nStartPos = nStart; DP3PYJ%+B
this.nEndPos = nEnd; \'|>p/5I
nThreadID = id; mGJasn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i(>4wK!!
} ;*:Pw?'
R'C2o]
eD*A)
public void run() P;Ga4Q.
{ MM(xk
while(nStartPos < nEndPos && !bStop) X4 A<[&F/
{ hRK/T7v
kzt(i Y_6
<})2#sZO!
try{ w-Da~[J
URL url = new URL(sURL); vTJ}8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %k'!Iq+
httpConnection.setRequestProperty("User-Agent","NetFox"); c.>oe*+
String sProperty = "bytes="+nStartPos+"-"; :TJv=T'p'
httpConnection.setRequestProperty("RANGE",sProperty); jO!y_Y]B
Utility.log(sProperty); O"F_*
R}q>O5O
r\/9X}y4z
InputStream input = httpConnection.getInputStream(); UFp,a0|
//logResponseHead(httpConnection); oxz OA
x "^Xj]-
P] UJ0b
byte[] b = new byte[1024]; "4uS3h2r
int nRead; C/TF-g-_Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e>(<eu~P
{ TWQG591
nStartPos += fileAccessI.write(b,0,nRead); f!!V${)X
//if(nThreadID == 1) X@K-^8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P!+'1KR
} cm&I* 0\
J6L K
DX"xy
Utility.log("Thread " + nThreadID + " is over!"); i`dCG[
bDownOver = true; w*oQ["SL
//nPos = fileAccessI.write (b,0,nRead); 9983aFam
} ?e,pN,4
catch(Exception e){e.printStackTrace ();} >hk=VyU;
} )u/yF*:n
} 6^%68N1k
dIRm q+d^
Qj.l:9%
//打印回应的头信息 1n:8s'\
public void logResponseHead(HttpURLConnection con) &?*V0luP)
{ u%$Zqee
for(int i=1;;i++) 1oN^HG6O
{ ENGg ~D
String header=con.getHeaderFieldKey(i); ;9#Z@]p
if(header!=null) ev#;t@^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qzlo'e1
Utility.log(header+" : "+con.getHeaderField(header)); Axe8n1*y
else SRrw0&ts
break; @@8J6*y
} #m{UrTC
} |aT| l^2R@
UG'9*(*
XVvK2(
public void splitterStop() k;w- E
{ .)<(Oj|4
bStop = true; rz@=pR :
} -lhLA`6_R
nIU6h
1rkE yh??
} B:!W$<
Z(Bp 0a
~[\_N\rm
/* jC7&s$>Q"g
**FileAccess.java IFDZfx
*//文件访问(定位，写) '+$EhFwD
package NetFox; }lfnnK#
import java.io.*; dVsE^jsL
$D}{]MN.
"QWq_R
public class FileAccessI implements Serializable{ r9 !Tug*>m
jz5qQt]^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sIK;x]Q)
RandomAccessFile oSavedFile; TJ1+g \
long nPos; M $Es%
.8P.)%
JvT"bZk(o
public FileAccessI() throws IOException }(1JaG
{ ~fT_8z
this("",0); pb$~b\s]=
} qU#BJON]BR
3AsT
z&{5;A}Q@
public FileAccessI(String sName,long nPos) throws IOException rxy&spX
{ ho0@ l
oSavedFile = new RandomAccessFile(sName,"rw"); ^d~1E Er
this.nPos = nPos; Pri`K/
oSavedFile.seek(nPos); 4Rvf
} #@"<:!?z
AKRTBjG"
e(I=^#u6
public synchronized int write(byte[] b,int nStart,int nLen) hrhb!0
{ Xt#4/>dlR
int n = -1; qt;y2gf=
try{ Hrzf'a|^
oSavedFile.write(b,nStart,nLen); t| 'N+-T3
n = nLen; `$B3X
} :@!ic<p
catch(IOException e) l?Fb ='#
{ @)-$kk*
e.printStackTrace (); &d5ia+#
} <~n$1aA
;d'Z|H;
m q{];
return n; ea~:}!-P
} OBP1B@|l$+
2c:#O%d(
a)#1{JaoY
} k}0^&Quc4
RhvfC5Hq
<F.Tx$s
/* JGH60|
**SiteInfoBean.java DNj"SF(J
*/ 2w-51tqm
package NetFox; Hx\H $Y
Pw;!uag
TM|)Ljm
public class SiteInfoBean { jMN[J|us51
,i,q!M{-
v0ES;
private String sSiteURL; //Site's URL [w&$|h:;
private String sFilePath; //Saved File's Path CBD6bl|A
private String sFileName; //Saved File's Name zBJ7(zh!
private int nSplitter; //Count of Splited Downloading File ea00\
zA!0l*H
_dJ{j
public SiteInfoBean() ]<q[Do8k
{//nSplitter的缺省值为5 _Jt 2YZdA
//default value of nSplitter is 5 t6A:ZmG_
this("","","",5); 1s{^X -
} {nvLPUL
GKFq+]W
3RR_fmMT)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =pk)3<GwF
{ <@Fy5k-%.
sSiteURL= sURL; N]<!j$pOz
sFilePath = sPath; D.1J_Y=9
sFileName = sName; {!K-E9_,S
this.nSplitter = nSpiltter; HCa
wu4NLgkE
p!<$vE
} {M?vBgR\B
?x0pe4^If
q=DN {a:
public String getSSiteURL() h'$9C
{ Y"6w,_'m
return sSiteURL; RNhJ'&SYs
} ]+m/;&0
m/@<c'i
9Y<#=C
public void setSSiteURL(String value) C>[fB|^
{ A,)VM9M_l
sSiteURL = value; >N?2""
} yx<WSgWZ[
Qo1eXMW
vYU;_R
public String getSFilePath() VT.;:Q
{ TcGoSj<Z
return sFilePath; h#hxOVl%x
} 5 XA=G
I6s3+x;O
&k1T08C*
public void setSFilePath(String value) *\o/q[
{ U7DCx=B
sFilePath = value; [M%9_CfZOy
} wV)}a5+
ee/&/Gt
2EK%N'H
public String getSFileName() }=2;
{ 7rC uu*M
return sFileName; ZJjTzEV%^B
} hHPs&EA.p
q,3;m[cA
xwH?0/
public void setSFileName(String value) $7'gRb4
{ {q3H5csFq
sFileName = value; wM_ 6{
} @Fpb-Qd"
-.|4Y#b:&
\Fe_rh
public int getNSplitter() :Yj)CGl$
{ \i[BP
return nSplitter; \bx~*FaX
} 3s>'hn
"z*:'8;E
?~QIALA
public void setNSplitter(int nCount) U5]pi+r
{ t nS+5F
nSplitter = nCount; _7D_72
} 4TwQO$C
} cFagz* !
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)!Bd6-
/* D5an\gE
**Utility.java X{g%kf,D=
*/ gLSA!#[h
package NetFox; $y?k[Y-~
G3G6IP
'&;69`FSe
public class Utility { -[Qvg49jy
Xm4CKuU@
(#oycj^<
public Utility() Sc]P<F7N]
{ 2Nj9U#A
[Lp,Hqi5
^MmC$U^n
} %Z8vdU#l
M]-VHI[&W
//线程睡眠 K{l5m{:%
public static void sleep(int nSecond) S }>n1F_
{ cMzkL%
try{ s(_+!d6
Thread.sleep(nSecond); c[ht`!P
} .!}hhiF,Z
catch(Exception e) $iM=4 3W
{ K"2|[5
e.printStackTrace (); Uw<&Wm`'
} x>~p;z#VX
} ~B$b)`*
!Do,>gO
//日志 B/"2.,
public static void log(String sMsg) MbXq`%
{ lr2rQo>
System.err.println(sMsg); c {I"R8
} p[WX'M0f
y>\S@I
Fpt-V
public static void log(int sMsg) 2>\\@1
{ 4UAvw
System.err.println(sMsg); zx1:`K0bi
} n$2RCQ
} \nqo%5XL
0v^:
T[Pa/j{
/* !CjqL~
**TestMethod.java \Z/k;=Sla
*/ ZB5?!.ND
package NetFox; MF[z-7
5A&y]5-Q`
V8O.3fo`[`
public class TestMethod { Vj; vo`T
Ih1|LR/c
*T4<&
public TestMethod() NfE.N&vI_c
{ ///xx/weblogic60b2_win.exe '9J|=z9.
try{ Napf"Av
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2@vj!U8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /!Z^Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); eFTX6XB:i
fileFetch.start(); 6(sIYZ2yq
} S2~@nhO`U(
catch(Exception e){e.printStackTrace ();} }iIbcA
`eRLc}aP2
g$j6n{Yl
} qvt-
/f1'm@8;
)qPSD2h
public static void main(String[] args) GLKO]y
{ 2r];V'r
new TestMethod(); zL s^,x
} !;>(ie\
} {aN(d3c
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