http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 4OOn,09
} <{cNgKd9
for(int i=0;i<nEndPos.length-1;i++) JYg% ~tW'
{ mYh5#E41J
nEndPos = nStartPos[i+1]; %`?;V;{=
} oO#xx)b
nEndPos[nEndPos.length-1] = nFileLength; mo;)0Vq2l
} p>:ef<.i
} G=Hf&l
t`Y!"l
8@%mnyQ
//启动子线程 N=T.l*8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EY)Gi`lK
for(int i=0;i<nStartPos.length;i++) a%T -Z.rd
{ gM3]%L_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /$9BPjO{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %/y`<lJz(
nStartPos,nEndPos,i); Z6^QB@moj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @1qdd~B}
fileSplitterFetch.start(); 9:%n=URd
} `D)Lzm R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,]Ro',A&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }{5mH:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wMz-U- z
nEndPos = " + nFileLength); v0Ai!#
// fileSplitterFetch[nPos.length-1].start(); iIsEQh
;n} >C' :
(rr}Pv%yb
//等待子线程结束 Gg9VS&VI
//int count = 0; @q&|MMLt
//是否结束while循环 ?L@@;tt
boolean breakWhile = false; WDEe$k4.
!.3R~0b
% Cu.u)/+
while(!bStop) WGh. ;-
{ L\}Pzxn
write_nPos(); ]am~aJ|L
Utility.sleep(500); U!c]_q
breakWhile = true; g5[D&
_\dt?(m|
SPkKiEdM
for(int i=0;i<nStartPos.length;i++) ?C &x/2lt
{ L`UG=7r q
if(!fileSplitterFetch.bDownOver) Q PFeBl
{ <t{?7_ 8
breakWhile = false; s) Cpi
break; |1(rr%
} EJZ@p7*Oj
} M%$DT
if(breakWhile) g ?afX1Sg
break; JFM"ii{8
2yN%~C?$
2wx!Lpr<i_
//count++; P</s)"@
//if(count>4) e(yQKwVD
// siteStop(); .Gizz</P~
} 5M%,N-P^
5-D`<\
Ag0]U
System.err.println("文件下载结束！"); ~ww?Emrw
} lDW!Fg
catch(Exception e){e.printStackTrace ();} [kbC'Eh*
} -IBO5;2_
x*.Ye5Jb
}B y)y;~
//获得文件长度 3{N\A5~
public long getFileSize() c 9rVgLqn!
{ fO].e"}
int nFileLength = -1; ]7a;jNQu
try{ [6D>f?z
URL url = new URL(siteInfoBean.getSSiteURL()); :GQUM6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I4)Nb WQ
httpConnection.setRequestProperty("User-Agent","NetFox"); ?75\>NiR
C"6Amnj
>']+OrQH
int responseCode=httpConnection.getResponseCode(); K~c^*;F
if(responseCode>=400) GDF{Lf)/v
{ U1l0Uke
processErrorCode(responseCode); $ye^uu;Z
return -2; //-2 represent access is error xXF2"+
} (NX)oP
ajW[eyX
nV'3sUvR#
String sHeader; $#5klA
Bi]D{m9
~}BJ0P(VMc
for(int i=1;;i++) vXephR'
{ W1vCN31
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KiQ(XNx
//Utility.log(in.readLine()); q"S(7xWS
sHeader=httpConnection.getHeaderFieldKey(i); SO`dnf
if(sHeader!=null) U\Ct/U&A?
{ Hk,lX r
if(sHeader.equals("Content-Length")) z^r|3;
{ |K%}}g[<e;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (@ "=F6P
break; '9qn*H`'
} 2G?$X?
} 1t+%Gv^sK
else tJ"az=?
break; XdpF&B&K7Q
} Rho5s@N7
} @0$}?2
catch(IOException e){e.printStackTrace ();} C` pp
catch(Exception e){e.printStackTrace ();} qNpu}\L
N[pZIH5ho=
jZRhKT
Utility.log(nFileLength); KxY$PgcC
RcQ>eZHl
G+U3wF],
return nFileLength; !2z!8kI
} l]H0g[
``!GI'^
QZ&4:K+{
//保存下载信息（文件指针位置） YgEM:'1f
private void write_nPos() +@0TMK,P
{ yO=p3PV d
try{ d/S+(<g
output = new DataOutputStream(new FileOutputStream(tmpFile)); +semfZ)
output.writeInt(nStartPos.length); rj3YTu`
for(int i=0;i<nStartPos.length;i++) &pM'$}T*
{ P*YK9Hl<
// output.writeLong(nPos); \m f*ge\
output.writeLong(fileSplitterFetch.nStartPos); <s_=-" il
output.writeLong(fileSplitterFetch.nEndPos); ?4 qkDtm
} BEWro|]cM
output.close(); ZRnL_z~
} pYt/378w
catch(IOException e){e.printStackTrace ();} QQFf5^
catch(Exception e){e.printStackTrace ();} Gg|M+M?+
} ]=x\b^
g`n;R
M'q'$)e
//读取保存的下载信息（文件指针位置） J*j5#V];
private void read_nPos() =h|wwQE
{ K#!X><B'
try{ +dw!:P&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %hc'dZ
int nCount = input.readInt(); 1* ^'\W.
nStartPos = new long[nCount]; SauH>
nEndPos = new long[nCount]; dv, C6t2
for(int i=0;i<nStartPos.length;i++) /Wu|)tx
{ U'y,YtF@
nStartPos = input.readLong(); 3;-^YG
nEndPos = input.readLong(); (bv,02
} hL!QLiF:
input.close(); L,?/'!xV
} h*3{6X#(/
catch(IOException e){e.printStackTrace ();} A2NF<ZsD
catch(Exception e){e.printStackTrace ();} 'tm$q/&
} g6%Z)5D]!
QL97WK\$
h%TLD[[/jr
private void processErrorCode(int nErrorCode) .wy$-sG81
{ WDkuB
System.err.println("Error Code : " + nErrorCode); Ly7!R$X
} H-I{-Fm
,3HcCuT
',{7%G9
//停止文件下载 jJBnDxsA
public void siteStop() L\e>B>u
{ R^%e1KO]
bStop = true; +}aC-&
for(int i=0;i<nStartPos.length;i++) [ ]^X`R
fileSplitterFetch.splitterStop(); FRZs[\I|iT
g$FEEDF
{U"^UuU]
} Qf xH9_
} ,a0pAj
//负责部分文件的抓取 ;Lo&}U3F,!
**FileSplitterFetch.java &:3Z.G
*/ _1L(7|^~y[
package NetFox; so+4B1$)q
!^y y0`k6
jQ=~g-y
import java.io.*; brSi<
import java.net.*; _U0$=V
{q3:Z{#>7
aXY-><
public class FileSplitterFetch extends Thread { 88lxHoPV
}gGkV]
V*RdDF7
String sURL; //File URL }T.?c9l X
long nStartPos; //File Snippet Start Position ?D|\]0eN
long nEndPos; //File Snippet End Position k6(r !mc
int nThreadID; //Thread's ID !%PWig-
boolean bDownOver = false; //Downing is over |c2xy
boolean bStop = false; //Stop identical WR#0<cz(
FileAccessI fileAccessI = null; //File Access interface PB53myDQ
XIAeCU
g=l:cVr8y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XiQkrZ
{ QTmZ(>z
this.sURL = sURL; W3rl^M=r
this.nStartPos = nStart; yGj.)$1},@
this.nEndPos = nEnd; U# JIs
nThreadID = id; z;Q<F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /nZ;v4
} 5$rSEVg9
zt=0o|k
bZ 443SG
public void run() &dR=?bz-A
{ |Au]1}
while(nStartPos < nEndPos && !bStop) cz/Q/%j$/
{ RJ4. kt
:+rUBYWx
)ev<7g9*q
try{ lfN~A"X
URL url = new URL(sURL); +&|S'7&{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f)Xr!7
httpConnection.setRequestProperty("User-Agent","NetFox"); :5fAPK2r<
String sProperty = "bytes="+nStartPos+"-"; j&R+2%
httpConnection.setRequestProperty("RANGE",sProperty); '%saL>0
Utility.log(sProperty); nV_8Ke
sOU_j:A80;
"v-(g9(
InputStream input = httpConnection.getInputStream(); Vz=auM1xZ
//logResponseHead(httpConnection); #Q"O4 b:8
PVOx`<ng
6Jz^
byte[] b = new byte[1024]; @Xp~2@I=ls
int nRead; *QGm//b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mLk(y*
{ |JF@6
nStartPos += fileAccessI.write(b,0,nRead); 1.<q3q
//if(nThreadID == 1) 5ETip'<KT6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J%H;%ROx
} kgdT7
ZraT3
]b/S6oc6
Utility.log("Thread " + nThreadID + " is over!"); cD|Htt"
bDownOver = true; <[:o !$
//nPos = fileAccessI.write (b,0,nRead); @%ip7Y]e
} cvd\/pG)
catch(Exception e){e.printStackTrace ();} \daZk/@
} 2{Vcb
} ?p<.Fv8.
F[ ajOb8
J(4"S o_
//打印回应的头信息 }Ew hj>w
public void logResponseHead(HttpURLConnection con) 6z0@I*
{ {--0z3n>
for(int i=1;;i++) 9^FziM
{ ~Nf})U
String header=con.getHeaderFieldKey(i); s~I6SA&i
if(header!=null) %p^.|Me7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PO:"B6
Utility.log(header+" : "+con.getHeaderField(header)); j>uj=B@
else 5tjP6Z`!9`
break; ~lNsa".c
} OU5*9_7.
} g V5zSudW
)^||\G
gz2\H}
public void splitterStop() J^R=dT!
{ m,C1J%{^
bStop = true; (C4fG@n
} H~ZV*[A`
^7zu<lX
HbP!KVHyk1
} JSh.]j<bJL
T91moRv
V%$/#sza
/* .EM`.
**FileAccess.java 2'=T[<nNB
*//文件访问(定位，写) ifN64`AhRX
package NetFox; uqz]J$
import java.io.*; }D+}DPL{^
pTIf@n6I
.bBdQpF-
public class FileAccessI implements Serializable{ |rmg#;/D
4pw6bK,s2\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D %Xo&V[
RandomAccessFile oSavedFile; quY:pqG38q
long nPos; MSf;ZB
{G?N E
dOa%9[
public FileAccessI() throws IOException LL:_L<
{ Ua!aaq&
this("",0); %^RN#_ro(3
} 95el'K[R
/SYw;<=
M4as
public FileAccessI(String sName,long nPos) throws IOException sr8cYLm5R
{ `OSN\"\ad
oSavedFile = new RandomAccessFile(sName,"rw"); v:H$<~)E|
this.nPos = nPos; y5!KXAQ%
oSavedFile.seek(nPos); T=ev[ mS
} yPq'( PV
c/sC&i;%O
82l~G;.n3
public synchronized int write(byte[] b,int nStart,int nLen) HTG%t/S
{ }_ 9Cxji
int n = -1; B_.%i+ZZ
try{ I_]^ .o1q
oSavedFile.write(b,nStart,nLen); ]q4rlT.i
n = nLen; @;"|@!l|
} V:joFRH9
catch(IOException e) z4N*b"QF
{ q@{Bt{$x
e.printStackTrace (); &v@a5L
} B6={&7U2
ez|)ph7
W)bLSL]`E
return n; PpzP7
} :=Nz}mUV
m^zUmrj[
HAa;hb
} YuO.yh_
U>Slc08N
iUN Ib
/* F'21jy&
**SiteInfoBean.java jWA(C;W
*/ LU!a'H'Q
package NetFox; gDpVeBd[
EFM5,gB.m
, K~}\CR
public class SiteInfoBean { [DI+~F
7fZDsj:
GBPo8L"9
private String sSiteURL; //Site's URL ;@oN s-
private String sFilePath; //Saved File's Path Fww :$^_ k
private String sFileName; //Saved File's Name Fj2BnM3#
private int nSplitter; //Count of Splited Downloading File 3EPv"f^V
p$]3'jw
0Qf,@^zL*
public SiteInfoBean() u7>],<
{//nSplitter的缺省值为5 (@fHl=! Za
//default value of nSplitter is 5 z7fp#>uw
this("","","",5); \!.B+7t=I
} 8}O lL,fP
ivJ@=pd)B
-(;26\lE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m#| 9hMu
{ t.i 8 2Q
sSiteURL= sURL; tEvut=k'
sFilePath = sPath; vN;N/mL
sFileName = sName; Yg||{
this.nSplitter = nSpiltter; nFHUy9q
.SU8)T
Yi%;|]
} qN9(S:_Px
U:0mp"
8Fz#A.%P
public String getSSiteURL() dO! kk"qn
{ Ot_]3:`J~
return sSiteURL; B9jC?I |`
} <lPm1/8
SJn;{X>)q
"^})zf~_
public void setSSiteURL(String value) ) j#`r/
{ P~>OS5^
sSiteURL = value; k<CJ{u0<
} {HltvO%8
un mJbY;t
hd%Fnykq
public String getSFilePath() l*Gvf_UH
{ NX*Q F+
return sFilePath; 'T*&'RQr
} _^Ubs>d=*
> PRFWO
5}l[>lF
public void setSFilePath(String value) e:DCej^z
{ xX&+WR
sFilePath = value; _Eo[7V{NY
} i#n0U/
G:<aB
i &nSh ]KK
public String getSFileName() tKOmoC
{ gV's=cQ
return sFileName; @1roe G
} HAdg/3Hw
g*AWE,%=|
Ko<:Z)PS
public void setSFileName(String value) <`=j^LU
{ e'NJnPO
sFileName = value; 8b&/k8i:
} JYI,N
{UI+$/v#
N)X3XTY
public int getNSplitter() xef% d G.
{ g wRZ%.Cn
return nSplitter; |tH4:%Q'
} Q~ w|#
Rsm^Z!sn
Vx u0F]%
public void setNSplitter(int nCount) -$ls(oot
{ 4SxX3Fw
nSplitter = nCount; q"lSZ; 'E
} <dtGK~_
} 6@5+m 0`u3
>1Ibc=}g
E<Y$>uKA
/* GR_-9}jQP
**Utility.java (mpNcOY<D
*/ $bR~+C
package NetFox; eu-*?]&Di
0Th&iA4
%YscBG
public class Utility { Czu9o;xr
194)QeoFw
ydA8wL
public Utility() TF\C@4Z
{ S9y}
gPI ?C76
K($Npuu]
} (y~TL*B
mO7]9p
//线程睡眠 1.GQau~
public static void sleep(int nSecond) O,f?YJ9S
{ <iC(`J$D
try{ i-_mTY&M
Thread.sleep(nSecond); .|70;
} Xc-'Y"}|`t
catch(Exception e) T.BW H2gRP
{ zTSTEOP}%Y
e.printStackTrace (); cF}".4|kZ<
} !*N@ZL&X
} Bnxm HGP#&
F^;ez/Gl
//日志 gR;i(81U
public static void log(String sMsg) 14yv$,
{ ^6V[=!& H
System.err.println(sMsg); "ze|W\Bv!
} &j"?\f?
kn4`Fa;)O
Bj;'qB>3
public static void log(int sMsg) {4Cmu;u
{ FvjPdN/L?R
System.err.println(sMsg); dR,fXQm
} 29.h91
} ?k{?GtSs
q>+k@>bk@
@q7I4
/* S4z;7z(8+
**TestMethod.java ?N9uu4
*/ p_%Rt"!
package NetFox; sUQ@7sTj
2fd{hJDq;5
H<,gU`&R
public class TestMethod { bq*eH (qx
iqWQ!r^
on`3&0,.
public TestMethod() 6LIJQ
{ ///xx/weblogic60b2_win.exe b3, _(;A!
try{ E ~<JC"]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G_,jgg7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >|UOz&
SiteFileFetch fileFetch = new SiteFileFetch(bean); fuySN!s
fileFetch.start(); 2c*GuF9(0
} BRiE&GzrF
catch(Exception e){e.printStackTrace ();} '~=SzO
/a4{?? #e
XW]tnrs
} 8{sGNCvU
-uf|w?
[7Oe3=
public static void main(String[] args) UP,c|
{ %7+qnH*;r
new TestMethod(); zK@@p+n_#.
} _q-*7hCQ`
} U>N1Od4vTO
点击下载更多相关资料