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)); | fAt[e_E
} 4ed+'-"m
for(int i=0;i<nEndPos.length-1;i++) %C*oy$.
{ PJu)%al
nEndPos = nStartPos[i+1]; yZ t}Jnv
} "|{O%X
nEndPos[nEndPos.length-1] = nFileLength; pqPhtWi%PJ
} =T$-idx1l
} k36%n *4
>&h#t7<
K29]B~0%E
//启动子线程 BJDe1W3;'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9.R)iA
for(int i=0;i<nStartPos.length;i++) @; ayl
{ w=Xil
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nA%H`/O{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q7O8']~n
nStartPos,nEndPos,i); ?C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GH2D5HVN
fileSplitterFetch.start(); SGn:f>N
} JF]HkH_u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L*tn>AO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mBgMu@zt)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }PGl8F !
nEndPos = " + nFileLength); D\8~3S'd
// fileSplitterFetch[nPos.length-1].start(); :(EU\yCzK
`INcZr"
|V{'W-` |[
//等待子线程结束 2ul!f7#E
//int count = 0; 7-81,ADv(
//是否结束while循环 HABMFv
boolean breakWhile = false; k WYjqv
gc@,lNmi
jj8AV lN
while(!bStop) C.dN)?O
{ =BpX;n<
write_nPos(); O.S(H1z<G
Utility.sleep(500); VJ P]Jy_
breakWhile = true; jJ-j
b@@`2O3"
6R% I)
for(int i=0;i<nStartPos.length;i++) RO,
{ az3rK4g
if(!fileSplitterFetch.bDownOver) \MM(w&
{ &G?b|Tb2
breakWhile = false; P X?!R4S
break; :|xV}
} lqe;lWC0Z
} rJK3;d?E
if(breakWhile) 6&7#?/Lq
break; -G2'c)DR
!=>pI/ECQ*
31-%IkX+k
//count++; lTsl=
//if(count>4) S!o!NSn@1
// siteStop(); :WejY`}H%
} :i+Tf~k{
{4tJT25
[aX'eMq
System.err.println("文件下载结束！"); p%5RE%u
} 3B95t-
catch(Exception e){e.printStackTrace ();} -%"Kxe
} !u)veh3x
Y( n# =
-#=v~vE
//获得文件长度 z>+@pj
public long getFileSize() lil1$K: i
{ a%DnRkRr
int nFileLength = -1; D]resk
try{ ZZp6@@zyq'
URL url = new URL(siteInfoBean.getSSiteURL()); I$v*SeVHE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 75}BI&t3k
httpConnection.setRequestProperty("User-Agent","NetFox"); Yd:8iJA
fLl~a[(5
ai[st+1
int responseCode=httpConnection.getResponseCode(); WP7*Q:5
if(responseCode>=400) };!S2+
{ A?'Tigi
processErrorCode(responseCode); `yJpDGh
return -2; //-2 represent access is error !]7r>NS>
} &^^zm9{
U#R=y:O?
2:^Dv1J)rD
String sHeader; Hj"`z6@7
fQq'_q5
_M= \s>;G
for(int i=1;;i++) 4M'y9(
{ ax&,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $5T3JOFz
//Utility.log(in.readLine()); _!kL7qJ"
sHeader=httpConnection.getHeaderFieldKey(i); %{g<{\@4(;
if(sHeader!=null) Dsc{- <v
{ sI/Jhw)
if(sHeader.equals("Content-Length")) zl\mBSBx"
{ (gZKR2hO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }6MHIr=o
break; }$r/#F/Fn
} }2;~':Mklz
} J@w Q3#5a
else eS9uKb5n(
break; ` WIv|S
} }8Tr M0q8
} ]Ec\!,54u
catch(IOException e){e.printStackTrace ();} Zoh[tO
catch(Exception e){e.printStackTrace ();} k2o98bK&;
Q.Tn"rE|
I|]~f[xI
Utility.log(nFileLength); 0\84~t'[
+G*2f V>
}stc]L{79
return nFileLength; ~]P_Yd-|
} #Q}`kFB`
4% )I[-sH
)J#7:s]eo
//保存下载信息（文件指针位置） 0L1NZY^!
private void write_nPos() oF[l<OY4
{ O`R@6KG
try{ |GJSAs"L@
output = new DataOutputStream(new FileOutputStream(tmpFile)); ={y Mk
output.writeInt(nStartPos.length); @w|'ip5@
for(int i=0;i<nStartPos.length;i++) dBkw.VOW
{ u*0Ck*pZ
// output.writeLong(nPos); OI</o0Ca
output.writeLong(fileSplitterFetch.nStartPos); 1TeYA6 t
output.writeLong(fileSplitterFetch.nEndPos); zLdi
} )e`$'y@L$
output.close(); fOs}5J
} 9q;n@q:29
catch(IOException e){e.printStackTrace ();} -@f5d
catch(Exception e){e.printStackTrace ();} daS l.:1
} N0h* |
aj;OG^(!2_
F@ lJk|*_
//读取保存的下载信息（文件指针位置） R@Ch3l@
private void read_nPos() X}C}
{ 6?u9hi
try{ ~ {OBRC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WZ`u"t^2V
int nCount = input.readInt(); M:i;;)cq
nStartPos = new long[nCount]; swEE >=
nEndPos = new long[nCount]; BMMWP
for(int i=0;i<nStartPos.length;i++) <Uf?7
{ ^"N]i`dIF
nStartPos = input.readLong(); kX!TOlk3
nEndPos = input.readLong(); FYU)sQ
} ,tBb$T)7<
input.close(); v;4l*)$)
} K1]m:Y<
catch(IOException e){e.printStackTrace ();} Obwj=_+upd
catch(Exception e){e.printStackTrace ();} f/Cf2 K
} Tov!X8p
S{_i1'
V4kt&61
private void processErrorCode(int nErrorCode) AdV&w: ^yf
{ G*.}EoA
System.err.println("Error Code : " + nErrorCode); Kv3cKNvu~
} @X\-c2=
SJ4[n.tPI
Q@zD'G>
//停止文件下载 ha_&U@w
public void siteStop() #_)<~
{ QEo i9@3
bStop = true; ?QuD:vck
for(int i=0;i<nStartPos.length;i++) . AJ(nJ)
fileSplitterFetch.splitterStop(); uEqL Dg
NVqJN$z
^5n"L29V
} 3Q'Q %2
} Te&F2`vo
//负责部分文件的抓取 fHK`u'
**FileSplitterFetch.java #qqIOjS^w
*/ I6!~(ND7
package NetFox; ?86q8E3;&
{uVvo=3
l!z)gto
import java.io.*; ~wtl\-cY
import java.net.*; iK&s_}i:
M'gw-^(
A#/O~-O^
public class FileSplitterFetch extends Thread { );-?~
AG?cI@',
?J[m)Uo/K
String sURL; //File URL "_!D b&AH
long nStartPos; //File Snippet Start Position GZ xG!r-
long nEndPos; //File Snippet End Position 3^NHVg
int nThreadID; //Thread's ID BC|=-^(
boolean bDownOver = false; //Downing is over [Aqy%mbG
boolean bStop = false; //Stop identical :Y/>] tS4
FileAccessI fileAccessI = null; //File Access interface VHwAO:+-
7{0;<@
?4p\ujc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X6hm,0[
{ ;Ih:$"$!
this.sURL = sURL; PtP{_9%Dz
this.nStartPos = nStart; 2Fwp\I;
this.nEndPos = nEnd; {p -q&k&R|
nThreadID = id; |ipL.<v7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Pv@P(y?\
} pGS!Nn;K2
,+LX.f&/8!
V $'~2v{_
public void run() =gSa?pd
{ :xqhPr]e
while(nStartPos < nEndPos && !bStop) M.b1=Y
{ :2+,?#W
,mkXUW
t]dtBt].:
try{ LU'<EXUbY
URL url = new URL(sURL); la37cG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mar6/*`I#+
httpConnection.setRequestProperty("User-Agent","NetFox"); B4fMD]
String sProperty = "bytes="+nStartPos+"-"; =v-qao7xCV
httpConnection.setRequestProperty("RANGE",sProperty); ."HDUo2D7
Utility.log(sProperty); E]T>m!6
{, +,:w7
q6R``
InputStream input = httpConnection.getInputStream(); >ucVrLm,X
//logResponseHead(httpConnection); 'E_M,Y
v2Lx4:dzi
l~_]k
byte[] b = new byte[1024]; SQ$|s%)oB
int nRead; c*fMWtPp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d2cslDd
{ Kyn[4Bu!?
nStartPos += fileAccessI.write(b,0,nRead); F@4TD]E0^
//if(nThreadID == 1) ;!RS q'L1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $@WqM$
} .X2fu/}
. }#R
suo;+T=`I
Utility.log("Thread " + nThreadID + " is over!"); rf}@16O$'
bDownOver = true; WDrC
//nPos = fileAccessI.write (b,0,nRead); QkY]z~P4
} :9nqQJ+~
catch(Exception e){e.printStackTrace ();} i-kj6N5
} ^a,Oi%
} I%4)%
">-J+ST%
*/8b)I}yY
//打印回应的头信息 OD;-0Bj
public void logResponseHead(HttpURLConnection con) 2=?:(e9
{ fv;3cxQp
for(int i=1;;i++) |<:Owd=
{ U"SH fI:
String header=con.getHeaderFieldKey(i); ,}8|[)"
if(header!=null) )\xDo<@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 06)B<
Utility.log(header+" : "+con.getHeaderField(header)); q4Rvr[
else 1$+-?:i C
break; CP5vo-/)-
} x-hr64WFK
} -}_X'h&"
,RA;X
jUtFDw
public void splitterStop() VXfp=JE
{ F'NX
bStop = true; uD'GI
} u*W6fg/"
/Soc,PjZ
Bz7rf^H`Z
} G@.TE7a2Z
bi:TX<K+
JI)@h 4b
/* .()|0A B&g
**FileAccess.java 6jDHA3
*//文件访问(定位，写) PN(P$6
package NetFox; 7{"urs7 T
import java.io.*; 3zr95$Mt
t9C.|6X
@2X{e7+D
public class FileAccessI implements Serializable{ d_ [l{
f+WN=-F\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jPDk~|
RandomAccessFile oSavedFile; L\GjG&Y5
long nPos; mi`jY0e2
`]T#uP<u
VKZZTFmV2)
public FileAccessI() throws IOException vq?aFX9F
{ P5$L(x%~
this("",0); b235Zm
} REK(^1 h
5LYzX+a)
OV.f+_LS
public FileAccessI(String sName,long nPos) throws IOException WP}NHz4H
{ $2><4~T;|A
oSavedFile = new RandomAccessFile(sName,"rw"); btG+Ak+K*
this.nPos = nPos; #?3oGrS Y
oSavedFile.seek(nPos); 9 SBVp6'
} [$x&J6jF.
GW;\3@o
t[|aM-F&>
public synchronized int write(byte[] b,int nStart,int nLen) 0]~'}
{ 3hD\6,@
int n = -1; 9w"kxAN
try{ ab@1JAgs
oSavedFile.write(b,nStart,nLen); VhfMj|
n = nLen; o`{@':%D`
} ?as1^~
catch(IOException e) U3-cH
{ DI)!x {"
e.printStackTrace (); ?l/$cO
} X+$IaLfCxD
CI8bHY$
>Ohh)$
return n; 810pJ
} -^f>=xa4J
|Nf90.dL
?TLzOYJp
} lx H3a :gm
[S:{$4&
^C|N
/* @dHQ}Ni
**SiteInfoBean.java ]Jum(1Bo
*/ >"/Sa_w
package NetFox; C25EIIdRb
vMHJgpd&j
sI OT6L^7
public class SiteInfoBean { X$0&tmum
[AA*B
vIQu"J&fE
private String sSiteURL; //Site's URL )wb&kug-
private String sFilePath; //Saved File's Path <l`xP)] X
private String sFileName; //Saved File's Name _@/nc:)H
private int nSplitter; //Count of Splited Downloading File I #bta
J+:gIszsWT
>s;>"]
public SiteInfoBean() mE)I(< %
{//nSplitter的缺省值为5 /4M~ 6LT`
//default value of nSplitter is 5 $:u5XJx
this("","","",5); 5<RZht$i
} ^!j,d_)b!
ui!MQk+D9
`%<^$Ng;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~6!TMVr
{ d#>iFD+
sSiteURL= sURL; of<(4<T
sFilePath = sPath; 1R"?X'w
sFileName = sName; )Zbrg~-@
this.nSplitter = nSpiltter; \ 0J&^C
?(2^lH~6h
.?NraydwV
} DRy,n)U&
d>-k-X-[
d#Xt2
public String getSSiteURL() tGVC"a
{ Y| 2Gj(*8
return sSiteURL; g7g^iLU
} /s|4aro
EpdSsfDP
? f>pKe
public void setSSiteURL(String value) G5hh$Nmpi
{ NB#-W4NA
sSiteURL = value; u~7 ,v
} fb;y*-?#
TChKm-x
i286`SLU
public String getSFilePath() n~C!PXE
{ L>>Cx`ASi
return sFilePath; M_ii
} ? 1 ~C`I;
=ec"G2$?"
ITr@;@}c]
public void setSFilePath(String value) Izr_]%
{ kY.3x#w
sFilePath = value; -V'h>K
} x17K8De
nAY'1!Oi
/gUD!@
public String getSFileName() )a0%62
{ %5rC`9^
return sFileName; bS"zp6Di
} L.R4 iN
2PVtyV3;
riz[AAB
public void setSFileName(String value) Kjfpq!NYE
{ p6|RV(?8
sFileName = value; 5A`T}~"X
} r.#"he_6!.
]aqg{XdGt
&* 1iW(x
public int getNSplitter() ai@hQJ*
{ *@SZ0
return nSplitter; wbA<G&h~
} ml\2%07
|xX>AMZc)D
*C"-$WU3o
public void setNSplitter(int nCount) 1?hx/02
{ f zsD
nSplitter = nCount; 'BmLR{[2L
} [rf.&
} -ttH{SslM
9:1[4o)~
~ u',Way
/* DF`?D +
**Utility.java | l|7[
*/ #[ZNiaWT
package NetFox; NpN-''B\
>2[nTfS
KV {J>J1
public class Utility { l0GsY.~,
:$5$H
R[T94U
public Utility() d&apu{
{ dub%fs
[44C`x[8M+
V9cKl[
} =}^J6+TVL
P{ HYZg
//线程睡眠 3wf&,4`EX
public static void sleep(int nSecond) y L|'K}
{ 9fQFsI
try{ 3sF^6<E
Thread.sleep(nSecond); hCFgZiH2
} 1p }:K`#{
catch(Exception e) 0kOl,%Ey
{ =>en<#[\:
e.printStackTrace (); Yp(F}<f?
} #cdrobJ
} ~;uc@GGo
m2h@*
//日志 *%;+3SV
public static void log(String sMsg) RwyRPc_
{ l:$i}.C
System.err.println(sMsg); TOC2[mc'
} ~&\}qz3
/CfgxPo
&w"1VOV<
public static void log(int sMsg) G}8Zkz@+
{ ~P;KO40K
System.err.println(sMsg); P<s0f:".
} zvAUF8'_
} SG@-b(
2T >K!jS
hiBZZ+^[
/* Q-7C'|
**TestMethod.java 3d81]!n
*/ 6xq/
package NetFox; jSc!"Trl]
j$ h>CZZ
Oiz@tEp=_
public class TestMethod { 6L}}3b h
_jCk)3KO
>.4mAO
public TestMethod() \!Cc[n(f#
{ ///xx/weblogic60b2_win.exe !eE;MaS>
try{ ?vn9HhTD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {.mPe|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i0/RvrLc
SiteFileFetch fileFetch = new SiteFileFetch(bean); m?)REE
fileFetch.start(); x_VD9
} yNc"E
catch(Exception e){e.printStackTrace ();} 14Y<-OO: k
'2X6>6`w
:Y)jf
} %3;vDB*L$
"`q:
g+1&liV
public static void main(String[] args) ~>-MVp
{ *JT,]7>
new TestMethod(); %8hjMds
} 05PRlz*x=
} P~d&PhOe
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