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)); aY-7K._</
} 6o d^+>U
for(int i=0;i<nEndPos.length-1;i++) PC!g?6J
{ ^D8~s;?
nEndPos = nStartPos[i+1]; aqEmF
} {/}%[cY=
nEndPos[nEndPos.length-1] = nFileLength; ey@ccc*sZ9
} ]{| wU.
} |/;;uK,y
p1N3AhXY
bRD-[)
//启动子线程 )uu(I5St
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +L|x^B3
for(int i=0;i<nStartPos.length;i++) QpD-%gN
{ 3O*^[$vM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &u2H^ j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xn=#4:f
nStartPos,nEndPos,i); %uw7sGz\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &WNIL13DK
fileSplitterFetch.start(); UvR.?js(O
} R-YNg
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A<_{7F9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ON9L+"vqv0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !oa/\p
nEndPos = " + nFileLength); Rt>mAU$}
// fileSplitterFetch[nPos.length-1].start(); goe%'k,
.*edaDi
FsLd&$?T&
//等待子线程结束 GL%)s?
//int count = 0; h S)lQl:^
//是否结束while循环 2]]}Xvx4#
boolean breakWhile = false; h~lps?.#b
ot0g@q[3
5PsjGvm.%
while(!bStop) Ya4yW9*
{ #mYe@[p@
write_nPos(); UD=[::##
Utility.sleep(500); qP0UcG
breakWhile = true; 22'Ra[
D-FT3Culw
{53|X=D64
for(int i=0;i<nStartPos.length;i++) `S+n,,l
{ iJH?Z,Tjf
if(!fileSplitterFetch.bDownOver) g/frg(KF
{ ;nrkC\SYh:
breakWhile = false; t$ 97[ay
break; *q"1I9zvT
} G.r .Z0
} gO{$p q}
if(breakWhile) cJf&R^[T
break; )t((x
l9e=dV:pH
9k\M<jA
//count++; *cZ7?
//if(count>4) M@JW/~p'
// siteStop(); nDcH;_<;9a
} h$mGawvZ~
PhAD:A
\l%##7DRp]
System.err.println("文件下载结束！"); a6@k*9D>
} jvxCCYXR
catch(Exception e){e.printStackTrace ();} &kcmkRRG
} RxS{
W[sQ_Z1C
z%BX^b$Hj
//获得文件长度 E@EP9X >
public long getFileSize() &c}2[=
{ PjofW%7F
int nFileLength = -1; |qVM`,%L
try{ =KAN|5yn
URL url = new URL(siteInfoBean.getSSiteURL()); ?D|kCw69SE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); * =*\w\ te
httpConnection.setRequestProperty("User-Agent","NetFox"); L1WvX6
*pDS%,$xe
p()LQT!
int responseCode=httpConnection.getResponseCode(); !L( )3=
if(responseCode>=400) k{O bm g
{ 1_TniR3z1
processErrorCode(responseCode); hYh~%^0dt
return -2; //-2 represent access is error D<:zw/IRE
} X,c`,B03
)3R5cq
c>3j$D+
String sHeader; *2fJdY
(&u'S+
C\Z5%2<Z
for(int i=1;;i++) [aG
{ 4T$DQK@e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &bGf{P*Da
//Utility.log(in.readLine()); d,o*{sM5d
sHeader=httpConnection.getHeaderFieldKey(i); 7kITssVHI
if(sHeader!=null) ~T/tk?:8Vi
{ f$5\ b[O
if(sHeader.equals("Content-Length")) _8ks`O#}
{ nN^lY=3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); unNN&m#@
break; =**Q\Sl
} %%#bTyF
} <Ql2+ev6
else 24 .'+3
break; GvvKM=1
} 9-vQn/O^D
} =Ot_P7'5gv
catch(IOException e){e.printStackTrace ();} Gx4{ 9
catch(Exception e){e.printStackTrace ();} )TyP{X>
]omBq<ox'Y
'vYt_T
Utility.log(nFileLength); !]5V{3
17`-eDd
?*[35XUd
return nFileLength; g7lPQ_A*
} x8x-b>|$&<
1|AY&u%fiP
fz?woVn
//保存下载信息（文件指针位置） :`lP+y?a1
private void write_nPos() }:u-l3e
{ Sx (E'?]
try{ |qwx3 hQ?
output = new DataOutputStream(new FileOutputStream(tmpFile)); f@$kK?c?
output.writeInt(nStartPos.length); d'H gek{T
for(int i=0;i<nStartPos.length;i++) |DPq~l(d
{ ms\\R@R
// output.writeLong(nPos); 6!USSipn
output.writeLong(fileSplitterFetch.nStartPos); gzy|K%K
output.writeLong(fileSplitterFetch.nEndPos); ]vPdj"7
} $pt~?ZZ3-
output.close(); mB6%. "
} GctV
catch(IOException e){e.printStackTrace ();} OEX\]!3_Fm
catch(Exception e){e.printStackTrace ();} LPZ\T}<l
} =6f)sZpPh
6__HqBQ
^t*Ba>A
//读取保存的下载信息（文件指针位置） 1*'gaa&y
private void read_nPos() 6.$z!~8
{ (i?9/8I
try{ 9Zmq7a E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w~jm0jK]
int nCount = input.readInt(); [@B!N+P5;
nStartPos = new long[nCount]; c.5u \I9"
nEndPos = new long[nCount]; \rO!lvX
for(int i=0;i<nStartPos.length;i++) +\u\BJ!LAJ
{ f! )yE`4-
nStartPos = input.readLong(); 'i:lV'
nEndPos = input.readLong(); 86!$<!I
} $ER9u2
input.close(); F-M)6&T
} 'H4?V
catch(IOException e){e.printStackTrace ();} B2KBJ4rI[1
catch(Exception e){e.printStackTrace ();} FFe{=H,=
} J\p-5[E
B/^o$i
H0yM`7[y
private void processErrorCode(int nErrorCode) e 'F:LMX
{ sY?wQ:
System.err.println("Error Code : " + nErrorCode); rx@i.+
} !,rF(pz
D~|q^Ms,%
fZLAZMrM
//停止文件下载 8<32(D{
public void siteStop() k7L4~W
{ R~|(]#com
bStop = true; ${}9/(x/^
for(int i=0;i<nStartPos.length;i++) 2- (}=N
fileSplitterFetch.splitterStop(); B@*!>R
:#{0yno)H
Iz;^D!
} Q`Q"p
} `*`ZgTV
//负责部分文件的抓取 #l.s>B4
**FileSplitterFetch.java OECVExb@eH
*/ yu>;m.e_
package NetFox; J!dv"Ww"
rusYNb1J
Fu\#:+5\
import java.io.*; j~>J?w9<O
import java.net.*; R6:m@
ipt]qJFd
8Bh micU
public class FileSplitterFetch extends Thread { hd[t&?{=
}odjaM}5Nc
TDWD8??e
String sURL; //File URL s8qpK; O
long nStartPos; //File Snippet Start Position Fpwhyls
long nEndPos; //File Snippet End Position rY1jC\
int nThreadID; //Thread's ID Ke]'RfO\
boolean bDownOver = false; //Downing is over ,^<39ng
boolean bStop = false; //Stop identical ^gNbcWc7CU
FileAccessI fileAccessI = null; //File Access interface ~?)y'?
AMO{ee7Po
L|1~'Fz#w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tL1\q Qg
{ ac966<#
this.sURL = sURL; _\= /~>Xl
this.nStartPos = nStart; 4cJ/XgX
this.nEndPos = nEnd; *,*XOd:3TL
nThreadID = id; gw%L M7yQR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :S!!J*0
} HCe/!2Y/%
>Rb jdM5K4
0dI7{o;<|
public void run() ,OP\^
{ 4!-R&<TLve
while(nStartPos < nEndPos && !bStop) Z@$'fX?~9
{ `Hv"^o
i }Zz[b
r(_Fr#Qn
try{ * kUb[
URL url = new URL(sURL); 5lM 3In@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d-W*`:Q
httpConnection.setRequestProperty("User-Agent","NetFox"); TIaiJvo
String sProperty = "bytes="+nStartPos+"-"; n!lE|if
httpConnection.setRequestProperty("RANGE",sProperty); [9Tnp]q
Utility.log(sProperty); "T<7j.P?
5LU7}v~/
sqjDh
InputStream input = httpConnection.getInputStream(); huR ^l
//logResponseHead(httpConnection); N+H[Y4c?F&
*A")A.R
9;`hJ!r
byte[] b = new byte[1024]; XaoVv2=G~
int nRead; 8,VEuBZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =)N6R
{ m6 Y0,9
nStartPos += fileAccessI.write(b,0,nRead); A2\3.3
//if(nThreadID == 1) /'_Yct=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v:>sS_^
} [biz[fm
+bb-uoZf
wqap~X
Utility.log("Thread " + nThreadID + " is over!"); ;vWJOvM2
bDownOver = true; f}ch1u>
//nPos = fileAccessI.write (b,0,nRead); fjuPGg~
} *#@{&Q(Qh
catch(Exception e){e.printStackTrace ();} ,:V[H8 ?
} 1:./f|m
} I?%#`Rvu
iU=:YPE+.
u09D`QPP]
//打印回应的头信息 +>c%I&h}`
public void logResponseHead(HttpURLConnection con) z U*Mk
{ AXnKhYlu
for(int i=1;;i++) (OavgJ+Y
{ D$w?
String header=con.getHeaderFieldKey(i); Bi"cWO
if(header!=null) e ^`La*n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8vfC
Utility.log(header+" : "+con.getHeaderField(header)); <$#^)]Ts
else at2)%V)
break; ?nE9@G5Gc
} _(8N*q*w
} RmOkb~
uBC#4cX`D*
1Vz3N/AP%?
public void splitterStop() {?A/1q4rr
{ 8)83j6VF
bStop = true; /;u=#qu(E-
} ')2LP;(
q%)."10}]
ltkA7dUbu
} 1$:O9{F
mQ<Vwx0
c{x:'@%/s'
/* ld5+/"$
**FileAccess.java zY-?Bv_D
*//文件访问(定位，写) qzSm]l?z
package NetFox; bhfKhXh8
import java.io.*; \`-xxhb?e
(&_^1
[g=4'4EZc
public class FileAccessI implements Serializable{ ?f!&M
e. E$Ej]w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zcio\P=^|B
RandomAccessFile oSavedFile; ,.;{J|4P
long nPos; O >@Q>Z8W?
^.*zBrFx
8hSw4S"$
public FileAccessI() throws IOException 7x*C` Et<x
{ ws U@hqS
this("",0); nS Vr,wU
} 4ZYywDwn
64^3ve3/a=
i@%a!].I
public FileAccessI(String sName,long nPos) throws IOException ogV v 8Xb
{ |F qujZz
oSavedFile = new RandomAccessFile(sName,"rw"); ?dk)2
this.nPos = nPos; |ss4pN0X
oSavedFile.seek(nPos); a,n#E!zT?w
} 4]xD-sc
lcfs 1].
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public synchronized int write(byte[] b,int nStart,int nLen) NZ+TTMv
{ "od2i\
int n = -1; %"|W qxv
try{ sn'E}.uhXH
oSavedFile.write(b,nStart,nLen); }"/>,
n = nLen; 0^F!-b^z
} e Dpt1
catch(IOException e) SI=7$8T5=5
{ (SA^>r
e.printStackTrace (); ],'"iVh
} dMI G2log
~Ds3-#mMy
{qs>yQ6a:-
return n; X3~@U7DU
} Oz<#s{Z
"DX2Mu=
/38XaKc{6
} )vY)Mg
F8\JL %
8RS@YO
/* @R`Ao9n9V
**SiteInfoBean.java tK6=F63e
*/ jFI`CA6P
package NetFox; MaF4lFmS
CWb*bw0
/HdjPxH
public class SiteInfoBean { ^#4<~zU
on1B~?*D
*{O[}
private String sSiteURL; //Site's URL tNYuuC%N
private String sFilePath; //Saved File's Path B!4~A{
private String sFileName; //Saved File's Name L}K8cB
private int nSplitter; //Count of Splited Downloading File ^bLFY9hSC
o76{;Bl\O
iUZV-jl2/
public SiteInfoBean() =i},$"Bf*%
{//nSplitter的缺省值为5 | _nBiHjNn
//default value of nSplitter is 5 VWk{?*Dp
this("","","",5); f`[E^zj
} iAt&927
p ^)3p5w
q-/t?m0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L08lkq,
{ %Vk77(
sSiteURL= sURL; WM ]eb, 8q
sFilePath = sPath; 8KsPAK_
sFileName = sName; NC sem
this.nSplitter = nSpiltter; <driD'=F
Tz&h[+6`
v]}\Ns/
} YhP+{Y8t
VDiW9]
p@oz[017/J
public String getSSiteURL() Ue!yK
{ f*Os~@K
return sSiteURL; 1R7tnR@[u
} xrv0%
T`GiM%R;g
.X:,]of
public void setSSiteURL(String value) hUEA)c
{ yA';~V\V{>
sSiteURL = value; wR"17z7[]
} |<MSV KW
B#3Q4c$
HumL(S'm
public String getSFilePath() 7"OJ,Mx%
{ xl@~K^c]
return sFilePath; bL5u;iy)
} ?.Ip(g
*JZlG%z
vx}BTH
public void setSFilePath(String value) >Sb3]$$
{ s@6Jz\<E
sFilePath = value; "/%o'Fq
} 2WE01D9O
1*.*\4xo
o/& IT(v
public String getSFileName() L-%'jR
{ m^w{:\p
return sFileName; 1\g r ;b
} `O`MW} c
hoLA*v2<
t/l<X]o
public void setSFileName(String value) P(a}OlG
{ %D~Mij
sFileName = value; R\]C;@J<
} -lR7 @S
{BgJ=0g?
yJ;Qe_up
public int getNSplitter() $#(j2sL1
{ o'8nQ Tao
return nSplitter; ;s-@m<
} tq51;L
LjIkZ'HuF
D0>Pc9
public void setNSplitter(int nCount) #$F*.vQSs+
{ 9TwKd0AT$&
nSplitter = nCount; I1I-,~hO
} <kWkc|zBY
} *]nk{jo2
`>OKV;~{z
6Cfsh<]b
/* %/qwqo`Q
**Utility.java z[y
*/ v8n^~=SH
package NetFox; Xg;;< /Z
mA@!t>=oMq
kI2+&
public class Utility { ae](=OQ
/Z[HU{4
ce; zn\
public Utility() lQy-&d|=#^
{ |kTq &^$
WBb*2
^;tB,7:*V
} f.$*9Fkw
|sEuhP\A3
//线程睡眠 Nr).*]g@~
public static void sleep(int nSecond) )uMv]
{ D4uAwmc
try{ d24_,o\_
Thread.sleep(nSecond); 7p1B"%
} 9A/bA|$
catch(Exception e) >0uj\5h)I]
{ A;dD'Kgl
e.printStackTrace (); Et0)6^-v
} *adznd
} ) .KMZ]
`zB bB^\`W
//日志 /)kx`G_
public static void log(String sMsg) PB!XApTb
{ hljKBx~
System.err.println(sMsg); _O;4>
} CGkx_E]
B^/k`h6J
o\; hF3
public static void log(int sMsg) 6As%<g=
{ Dwr 9}Z-]
System.err.println(sMsg); Bf6i{`!G
} E+LQyvF[
} "_&c[VptWi
xGOVMo +
L./c#b!{
/* g-1j#V`5
**TestMethod.java X$6QQnyR
*/ Y=g]\%-PB
package NetFox; 7upWM~H^
fre5{=@
pLys%1hg
public class TestMethod { /J&ks>St
*N}$~N
E31YkD.A
public TestMethod() 7#NHPn
{ ///xx/weblogic60b2_win.exe O.-n&U9
try{ $EEn]y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M&<qGV$A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _:WNk(
SiteFileFetch fileFetch = new SiteFileFetch(bean); x+;y0`oL
fileFetch.start(); =N8_S$nx(
} 29VX-45
catch(Exception e){e.printStackTrace ();} m l@%H
V|[NL4
+|7N89l
} DEt!/a{X
z[myf]@
x<' $
public static void main(String[] args) ;R Jv7@
{ k7;i^$@c
new TestMethod(); /wl]kGF
} U_j[<.aN)
} A*A/30o|R
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