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)); MyaJhA6c
} *5d6Q
for(int i=0;i<nEndPos.length-1;i++) eH^~r{{R
{ VQl(5\6O
nEndPos = nStartPos[i+1]; /[+%<5s
} w'7=CzfYn
nEndPos[nEndPos.length-1] = nFileLength; f_'8l2jK1i
} ?3a:ntX h
} <P.'r,"[
(Fs{~4T
Usq.'y/o
//启动子线程 *=zv:!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &l?AC%a5
for(int i=0;i<nStartPos.length;i++) IA680^
{ }va>jfy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C@{-$z)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {fa3"k_ke
nStartPos,nEndPos,i); AA<QI'6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e\r%"~v
fileSplitterFetch.start(); ()e|BFL.
} T( fcE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aKz:hG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZaF9Q%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <h%I-e6
nEndPos = " + nFileLength); p} {H%L
// fileSplitterFetch[nPos.length-1].start(); 9PdD=9HH
pT/z`o$#V
:*Y2na)qQ
//等待子线程结束 sW@_' Lw
//int count = 0; ZQ{-6VCjl
//是否结束while循环 Z}S7%m
boolean breakWhile = false; Vrs?VA`v$
Oi<yT"7
XIn,nCY;
while(!bStop) 'OvM
{ oI-,6G}
write_nPos(); 2P^x'I
Utility.sleep(500); -\n%K
breakWhile = true; us+z8Mz
Z@}qL1
?AK`M #M
for(int i=0;i<nStartPos.length;i++) HI7w@V8Ed
{ VS>xvF
if(!fileSplitterFetch.bDownOver) */2nh%>$
{ bEln.)
breakWhile = false; 54=*vokX_
break; inh J|pe"
} me@)kQ8M
} qA"BoSw4
if(breakWhile) DLuaM?7
break; 5Dzf[V^]`
:$0yp`k
hZlHY9[t?
//count++; 5?Pf#kq
//if(count>4) v3]5`&3~
// siteStop(); .f"1(J8
} RLZfXXMn
-K3d u&j
GUZ.Pw
System.err.println("文件下载结束！"); 6%}`!_N<Mc
} ) J.xQ}g
catch(Exception e){e.printStackTrace ();} 2vh }:A_
} (cyvE}g
Q-rG~O9-
zw+RDo
//获得文件长度 at4JLbk
public long getFileSize() {2YqEX-I*
{ 7F2 RH 8)
int nFileLength = -1; `S0`3q}L3%
try{ O-[
URL url = new URL(siteInfoBean.getSSiteURL()); ?|98Y"w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y0`; br\X
httpConnection.setRequestProperty("User-Agent","NetFox"); ?dbSm3
6<T:B[a-
`+rwx
int responseCode=httpConnection.getResponseCode(); '%wSs,HD
if(responseCode>=400) ]A5Y/dd
{ Q4_r) &np
processErrorCode(responseCode); Ar[|M2|
return -2; //-2 represent access is error ^lt2,x
} 9!(%Vf>
~\<$H'
}Nd1'BVf
String sHeader; 8lzoiA_9
2]Il:>n,
Z|Oq7wzEH
for(int i=1;;i++) 8["%e#%`$
{ Jx~H4y=z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r5N TTc
//Utility.log(in.readLine()); 0FtwDM))
sHeader=httpConnection.getHeaderFieldKey(i); C#nT@;VO5
if(sHeader!=null) )v_v 7 ~H&
{ Jw8?o/1D@
if(sHeader.equals("Content-Length")) !u@P\8M}
{ ;cvMNU$fN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NLY=o@<
break; (_"Zbw%cJy
} ;b*qunJ3L
} Bh'fkW3
else Q5T3
break; a`n)aXU l
} 'mbLK#q
} T>'O[=UWh
catch(IOException e){e.printStackTrace ();} &`@YdZtd"
catch(Exception e){e.printStackTrace ();} D$K'Qk
c>K]$;}
9Z!n!o7D
Utility.log(nFileLength); 05R"/r*
U,#x\[3!Jt
A~PR
return nFileLength; +4_,, I
} /]3[|
i,r:R g~
'Og@<~/Xy
//保存下载信息（文件指针位置） :vb5J33U
private void write_nPos() 88v8lt;R
{ p"p~Bx
try{ kEnGr6e
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?-<lIFFh
output.writeInt(nStartPos.length); UgGa]b[9A
for(int i=0;i<nStartPos.length;i++) ]|tg`*l!>
{ }x`Cnn
// output.writeLong(nPos); &]o-ZZX
output.writeLong(fileSplitterFetch.nStartPos); NUYKMo1ze
output.writeLong(fileSplitterFetch.nEndPos); c%/b*nQ(=
} |T""v_q
output.close(); ~^' ,4<K-}
} %US&`BT!
catch(IOException e){e.printStackTrace ();} =0d|F 8
catch(Exception e){e.printStackTrace ();} -i:WA^yKgw
} z qq
y<Q"]H.CkQ
\t7yH]:>@
//读取保存的下载信息（文件指针位置） xKSQz
private void read_nPos() _M`ZF*o=c
{ =4eJ@EVM
try{ >n09K8 A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T06(Q[)
int nCount = input.readInt(); Dm)B? H"
nStartPos = new long[nCount]; _eiqs
nEndPos = new long[nCount]; gQ{ #C'
for(int i=0;i<nStartPos.length;i++) :>fT=$i@
{ WT ;2aS:
nStartPos = input.readLong(); m>vwpRBOA
nEndPos = input.readLong(); !#)t<9]fv
} >4X2uNbZS
input.close(); K|Sq_/#+U
} cuQ!"iH
catch(IOException e){e.printStackTrace ();} +-<G(^
catch(Exception e){e.printStackTrace ();} e3;&
} L?[m$l!T}
{Ge{@1
*lSu=dk+
private void processErrorCode(int nErrorCode) [;z\bV<S
{ Qfm$q~`D^W
System.err.println("Error Code : " + nErrorCode); f#!+l1GV
} !{jw!bB
ez'NHodwk2
&THtQ1D
//停止文件下载 `MI;.t
public void siteStop() B"&-) (
{ 2o?j{K
bStop = true; a*cWj}u
for(int i=0;i<nStartPos.length;i++) Km(i}:6"
fileSplitterFetch.splitterStop(); ;W?#l$R
7\ _MA!:<
d~u=,@FK
} uBRlvNJ
} =1Sny7G
//负责部分文件的抓取 :01d9|#
**FileSplitterFetch.java MI`qzC*%
*/ GI]\
package NetFox; 12Oa_6<\0;
?sk>Mzr
dkw.o.e
import java.io.*; ^N/d`IAjv
import java.net.*; sjyr9AF
`7=$I~`
w#b@6d
public class FileSplitterFetch extends Thread { KmNnW1T
v?VDASR2`
V5K/)\#
String sURL; //File URL ?/o 8f7Z
long nStartPos; //File Snippet Start Position -hXKCb4YU
long nEndPos; //File Snippet End Position #sw4)*v
int nThreadID; //Thread's ID o.ZR5`.
boolean bDownOver = false; //Downing is over LaQ7A,]
boolean bStop = false; //Stop identical P2'N4?2
FileAccessI fileAccessI = null; //File Access interface R/oi6EKv
Y%?S:&GH
p*b_"aF1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lI?P_2AaS
{ g!XC5*}
this.sURL = sURL; )$!b`u
this.nStartPos = nStart; O>h`
this.nEndPos = nEnd; Y1h)aQ5{
nThreadID = id; 8s)b[Z5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uHKEt[PS$
} OyO]; Yk
>:-e
uN)c!='I
public void run() !5}}mf
{ +cH>'OXoB
while(nStartPos < nEndPos && !bStop) tKV,
{ N6._Jb
EnWv9I<
(I$%6JO:
try{ x@OBGKV
URL url = new URL(sURL); osXEzr(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |`o|;A]
httpConnection.setRequestProperty("User-Agent","NetFox"); Eiu/p&ct
String sProperty = "bytes="+nStartPos+"-"; >=0]7k;
httpConnection.setRequestProperty("RANGE",sProperty); ,'0#q
Utility.log(sProperty); V[(fE=cIN~
u ]"fwkL
h^ Cm\V
InputStream input = httpConnection.getInputStream(); \ivxi<SR
//logResponseHead(httpConnection); ID_4M_G
+;~N; BT
8NfXYR#
byte[] b = new byte[1024]; .Exvuo`F
int nRead; Z{B e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v":q_w<k
{ uA#K59E+
nStartPos += fileAccessI.write(b,0,nRead); 8_}t,BC
//if(nThreadID == 1) tY;<S}[@7w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pdf-2 Tx
} MSmr7%g3D
f0H.$UAL
Po)U!5Tm
Utility.log("Thread " + nThreadID + " is over!"); :xr^E]
bDownOver = true; :Dty([
//nPos = fileAccessI.write (b,0,nRead); 84WDR?
} )9nW`d+
catch(Exception e){e.printStackTrace ();} '6M6e(
} yn\c;Z
} n}UJ-\$
lMFo)4&P
L?/AKg
//打印回应的头信息 HF*0
public void logResponseHead(HttpURLConnection con) }*(_JR4G
{ 3JGrJ!x
for(int i=1;;i++) *>a=ku:?
{ $l*?Ce:
String header=con.getHeaderFieldKey(i); 08xo_Oysq
if(header!=null) ]owgsR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JH\:9B+:L
Utility.log(header+" : "+con.getHeaderField(header)); IVPN=jg?
else +%XByY5
break; #ELeW3 S}
} L(yUS)O
} D \i]gfu8W
v's1&%sM
trDw|WA
public void splitterStop() [ iTP:8
{ l+6c|([
bStop = true; )>1}I_1j)
} ]B )nN':
>>T7;[h
5@5*}[M
} y!1X3X,V
T{ @@V
/ ]8e[t>!f
/* 3g4=as4w
**FileAccess.java )'m;a_r`
*//文件访问(定位，写) ~qqxHymc
package NetFox; XnP?hw%
import java.io.*; ;J|t-$Z
!M8_PC*a
DyqqY$ vH(
public class FileAccessI implements Serializable{ fof}I:vO
fYPu%MN7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [RKk-8I
RandomAccessFile oSavedFile; :lXY% [!6P
long nPos; AM=,:k$
4}DFCF%B
QD0x^v8
public FileAccessI() throws IOException JE}VRMNr
{ 9@CRL=
this("",0); J\@g3oGw
} ZY8.p
C:No ^nH>
Tl yyJ{~
public FileAccessI(String sName,long nPos) throws IOException |?J57(
{ Lx>[`QT
oSavedFile = new RandomAccessFile(sName,"rw"); YT?Lt!cl=
this.nPos = nPos; m4~ |z
oSavedFile.seek(nPos); -6J <{1V
} ?ja%*0 R
4*Hzys[{
j~Pwt9G
public synchronized int write(byte[] b,int nStart,int nLen) MH)V=xU|)
{ Ba?1q%eG
int n = -1; m19\H
try{ \%r0'1f
oSavedFile.write(b,nStart,nLen); tXA?[ S
n = nLen; (b~l.@xh
} A-L1vu;
catch(IOException e) ~x(|'`
{ o5J6Xi0+
e.printStackTrace (); muXP5MO
} @_"cMU!
i/*)1;xsk
pf'DbY!
return n; L/Kb\\f
} a$?d_BX
PeIi@0vA
p4IyKry,
} !pU^?Hy=
>Z*b0j
h0m5oV
/* (M|DNDM'd
**SiteInfoBean.java &8f/6dq
*/ u9Adu`
package NetFox; h-Y>>l>PW0
{hN\=_6*EW
&Y@),S9
public class SiteInfoBean { e;~(7/1
Y(`Bc8h
msCz\8Xd
private String sSiteURL; //Site's URL x1`w{5;C 2
private String sFilePath; //Saved File's Path du}HTrsC
private String sFileName; //Saved File's Name %pWJ2J@
private int nSplitter; //Count of Splited Downloading File >0:3CpO*
6 Q7MAP M
tk-)N+M.
public SiteInfoBean() J V}7c$_
{//nSplitter的缺省值为5 d~_5Jx
//default value of nSplitter is 5 i@6g9\x+
this("","","",5); F$4=7Njv
} <,p$eQ)T%
x])j]k
([a;id
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q("l?'
{ + AjV0#n
sSiteURL= sURL; A #SO}c
sFilePath = sPath; 4MDVR/Z7
sFileName = sName; 3ONWu
this.nSplitter = nSpiltter; 7}\AhQ, S
fh_:ung
_"D J|j
} 1Zk1!> ?
1$# r)S[*
<oP`\m
public String getSSiteURL() PDc4ok`)
{ $=>:pQbBVX
return sSiteURL; B^/Cx
} 0Z((cI\J
:T6zT3(")D
GM;uwL#
public void setSSiteURL(String value) d72( g$F
{ R.* k7-(;
sSiteURL = value; ~ cu+QR)
} c uAp,!
K4NzI9@
J+0 ?e9
public String getSFilePath() ^cW{%R>XY
{ =$~x]
return sFilePath; xzMpTZQ
} 2.j0pg .
c\P}ZQ
*2pE39
public void setSFilePath(String value) 4;Hm%20g
{ h\)ual_r[j
sFilePath = value; @:'E9J06
} 26_PFHQu4
;$!0pxL)s
MD1d
public String getSFileName() <;+QK=f
{ zYPvpZV/
return sFileName; } -hH2
} WV|9d}5
YE"MtL {
c7?|Tipc
public void setSFileName(String value) 3PzF^8KJ
{ )086u8w )y
sFileName = value; bX`]<$dr3
} xU.Ymq& 5
*0a7H$iQ(]
S +73 /Vs
public int getNSplitter() bw#\"uJ
{ s5d[sx
return nSplitter; 9%P$e=Ui#
} '+^XL6$L
8fWnKWbbjw
blbzh';0}
public void setNSplitter(int nCount) 'i/"D8
{ kc2E4i
nSplitter = nCount; {;UBW7{
} OH+2)X
} z"sv,W
3@;24X
aI\>=*HF
/* ok&v+A
**Utility.java .$x822
*/ <&M5#:u
package NetFox; [z}$G:s
99q$>nx,w
,n5 [Y)
public class Utility { Zr\G=0`
1-4*YrA
]=0D~3o3
public Utility() +w3k_^X9c
{ x4_FG{AIu
7 Uu
9JC8OSjJ
} !.{{QwZ
i6h0_q8 >
//线程睡眠 6ozBU^n
public static void sleep(int nSecond) w$I$xup
{ ~Oj-W6-+&,
try{ +qF,XJ2
Thread.sleep(nSecond); 9VTE?,
} O >&,h^
catch(Exception e) WgV[,(
{ +7)/SQM5
e.printStackTrace (); ^yF2xJ)9-
} <J1$s_^`
} !3at(+4
Lr(wS {
//日志 b(g?X (&
public static void log(String sMsg) }xzbg
{ $0E_4#kwB
System.err.println(sMsg); 1T7;=<g`
} A832z`
pK2n'4 C
_UeIzdV9
public static void log(int sMsg) 0l%|2}a
{ ] yXrD`J!
System.err.println(sMsg); J 9k~cz
} ! XNTk]!
} 9o5_QnGE
y {1p#
nxYp9,c"
/* 1(U\vMb
**TestMethod.java <wt9K2,
*/ .hXdXY
package NetFox; d5B96;3
_9zydtw
u%Yr&u
public class TestMethod { ]O;Rzq{D(
)%5T*}j
s*pgR=dZZ
public TestMethod() "Q@ZS2;A
{ ///xx/weblogic60b2_win.exe !tD,phca~
try{ {YgB?kt5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }h)[>I(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bQM_rqjJGw
SiteFileFetch fileFetch = new SiteFileFetch(bean); |[lM2
fileFetch.start(); ddD $ 4+
} Z)zmT%t
catch(Exception e){e.printStackTrace ();} [HhdeLOX
U~8 oE_+
Z66@@?`
} S}*%l)vfR
@=[SsS
)TcW.d6
public static void main(String[] args) $r=Ud >
{ `5Qo*qx
new TestMethod(); 4 p(KdYc
} OW<5,h
} d<v>C-nk%
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