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)); Lp"OXJ*es
} IO&U=-pn&
for(int i=0;i<nEndPos.length-1;i++) $?!]?{K
{ ?7)v:$(G}
nEndPos = nStartPos[i+1]; 4~A$u^scn
} "oiN8#Hf
nEndPos[nEndPos.length-1] = nFileLength; _vb'3~'S
} ?fP3R':s
} Y|b,pC|,
^ )"Il
CG@Fn\J
//启动子线程 49>b]f,Vc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4a&8G
for(int i=0;i<nStartPos.length;i++) eD(5+bm
{ ld#x'/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {[:C_Up)f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), raOuD3
nStartPos,nEndPos,i); N LQ".mM+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f U=P$s
fileSplitterFetch.start(); AfhJ6cSIE
} aaf}AIL.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f*"T]AX0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z.SKawm6T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *-fd$l.
nEndPos = " + nFileLength); a+J>
// fileSplitterFetch[nPos.length-1].start(); 6Q>:vQ+E
oV['%Z'
tA4Ra,-c
//等待子线程结束 n6,YA2yZO
//int count = 0; :4 z\Q]
//是否结束while循环 3QZm *. /"
boolean breakWhile = false; OAiW8BAe
(y?F8]TfM
_kRc"MaB
while(!bStop) p{_*<"cfYn
{ |S).,B
write_nPos(); gCsN\z
Utility.sleep(500); 6 %aaK|0
breakWhile = true; B*}]'
VHqoa>U,*
7neJV
for(int i=0;i<nStartPos.length;i++) ct|0zl~
{ {*n<A{$[ m
if(!fileSplitterFetch.bDownOver) [G|(E
{ B%u[gNZ
breakWhile = false; +J{ErsG?6P
break; _3%:m||,XP
} Y)lr+~84f
} ><IWF#kUA
if(breakWhile) IEm~^D#<=
break; (||qFu9a
'ParMT
8Uh|V&
//count++; SD*q+Si,1U
//if(count>4) PHT<]:"`<
// siteStop(); 'l!\2Wv2
} l,Y5VGiH#
Oprfp^L
*szs"mQ/
System.err.println("文件下载结束！"); SX'NFdY
} h*JN0O<b
catch(Exception e){e.printStackTrace ();} W3Ee3
} S9$,.aq
3)CIqN
aynaV
//获得文件长度 E<! L^A M`
public long getFileSize() =AzkE]
{ Z@x&
int nFileLength = -1; cs\=8_5
try{ t 3N}):
URL url = new URL(siteInfoBean.getSSiteURL()); t@#5 G* _Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (i(E~^O
httpConnection.setRequestProperty("User-Agent","NetFox"); EI?8/c
vvY?8/
5CcX'*P
int responseCode=httpConnection.getResponseCode(); _hl| 3 eW5
if(responseCode>=400) r90tXx
{ `EMGrw_
processErrorCode(responseCode); \fC;b"j
return -2; //-2 represent access is error 6W3oIt
} ]Oo!>iTQi
:epB:r
p`7d9MV^
String sHeader; ]<YS7.pT
q Sv!5&u
+PsR*T
for(int i=1;;i++) 7;'UC','
{ aw lq/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 52# *{q}
//Utility.log(in.readLine()); +,R!el!o~u
sHeader=httpConnection.getHeaderFieldKey(i); `%#_y67v
if(sHeader!=null) KLG.?`h:
{ r8*xp\/
if(sHeader.equals("Content-Length")) !WGQ34R{
{ S/pU|zV[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TBJ?8W(
break; euT=]j
} <W3p!
} 7z, $
else OA9P"*
break; 91&=UUkK?
} MTl @#M
} ^)Y3V-@t
catch(IOException e){e.printStackTrace ();} &Q"vXs6Gt
catch(Exception e){e.printStackTrace ();} Brs}
bvZD@F`2
Zp_j\B
Utility.log(nFileLength); RaTNA W)v>
NW0se DL
3"0QW4A
return nFileLength; =z9,=rR4
} 7|dm"%@
U,yZ.1V^:
}0H<G0
//保存下载信息（文件指针位置） S3U]AH)C
private void write_nPos() -b+)Dp~$p
{ D1>*ml
try{ @|ZUyat
output = new DataOutputStream(new FileOutputStream(tmpFile)); b|x B<
output.writeInt(nStartPos.length); x%@M*4:&
for(int i=0;i<nStartPos.length;i++) GadY#]}(
{ V#b*:E.cA
// output.writeLong(nPos); <x;g9Z>(
output.writeLong(fileSplitterFetch.nStartPos); jM6$R1HX
output.writeLong(fileSplitterFetch.nEndPos); F+R1}5-3cl
} B&59c*K
output.close(); Z \ @9*
} zSsBbu:
catch(IOException e){e.printStackTrace ();} LR#.xFQ+
catch(Exception e){e.printStackTrace ();} =M@)qy
} \J?&XaO=
^hEN
V?^qW#AG
//读取保存的下载信息（文件指针位置） Xu_1r8-|=b
private void read_nPos() Qz{Vl>"
{ BSSehe*
try{ .uX(-8n ~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !7#*Wdt+P
int nCount = input.readInt(); j&A9 &+w
nStartPos = new long[nCount]; Fv/{)H<:y
nEndPos = new long[nCount]; (qc<'$o
for(int i=0;i<nStartPos.length;i++) oliVaavj
{ 13 JG[,w
nStartPos = input.readLong(); ;2fzA<RkK
nEndPos = input.readLong(); d9e~><bPJ
} j/T@-7^0
input.close(); 1+M !EW
} |yOIC,5[JW
catch(IOException e){e.printStackTrace ();} Qqb%^}Xx'u
catch(Exception e){e.printStackTrace ();} *Y53bZ
} H)*%eG~
K|~!oQ
#vy[v22
private void processErrorCode(int nErrorCode) &2@Rc?!6_P
{ ;Cx`RF w
System.err.println("Error Code : " + nErrorCode); ~^Ga?Q_
} >c:nr&yP
HH(2
],R\oMYy|P
//停止文件下载 -2U|G
public void siteStop() 1T~`$zS7
{ d*([!!i
bStop = true; BUh(pS:
for(int i=0;i<nStartPos.length;i++) 1,Pg^Xu
fileSplitterFetch.splitterStop(); "GqasbX
TK>~)hc}
l!j=em@
} 7I(QTc)*
} $V<fJpA
//负责部分文件的抓取 $'*{&/@
**FileSplitterFetch.java _Eq,udCso
*/ j9Z1=z
package NetFox; ,FRa6;
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i}<fg*6@E
import java.io.*; 0H}O6kU
import java.net.*; 5PpS/I:on
3v#F0s|
jM{5nRQ
public class FileSplitterFetch extends Thread { 4|eI_u{_
mSFA i
-=1>t3~\
String sURL; //File URL cUi6 On1C
long nStartPos; //File Snippet Start Position 11fV|b%
long nEndPos; //File Snippet End Position h;cw=G
int nThreadID; //Thread's ID KUq(&H7
boolean bDownOver = false; //Downing is over =7~;*Ts
boolean bStop = false; //Stop identical #.}&6ZP
FileAccessI fileAccessI = null; //File Access interface XK0lv8(
[Q8vS;.
<1~_nt~(*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [*ug:PG
{ K7qR
this.sURL = sURL; 6k37RpgH
this.nStartPos = nStart; *'n=LB8R
this.nEndPos = nEnd; {ueDwnZ
nThreadID = id; rXGaav9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2'ws@U}lR
} J}@.f-W\j
_t X1z^
FPE6H:'
public void run() #xq|/JWs
{ ?%Pi#%P
while(nStartPos < nEndPos && !bStop) vhU $GG8
{ XzBl }4s
56Lt "Z F
a63Ud<_a7
try{ \:Hh'-77q
URL url = new URL(sURL); 3Z}m5f`t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P!&yYR\
httpConnection.setRequestProperty("User-Agent","NetFox"); 7$L*nf
String sProperty = "bytes="+nStartPos+"-"; E|VTbEYG
httpConnection.setRequestProperty("RANGE",sProperty); 8*]dAft
Utility.log(sProperty); lb}:!Y
[F27i#'I]
4 `}6W>*R
InputStream input = httpConnection.getInputStream(); niPqzi
//logResponseHead(httpConnection); yyVE%e5nl
CSFE[F63
?IiFFfs
byte[] b = new byte[1024]; A;;OGJ,!\
int nRead; }hc+ENh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2.a{,d
{ soB_j
nStartPos += fileAccessI.write(b,0,nRead); 4)snt3k
//if(nThreadID == 1) catJC3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]6WP;.[
} BDi+*8
2d OUY $4
wFL7JwK:G
Utility.log("Thread " + nThreadID + " is over!"); ]#FQde4]5
bDownOver = true; s*e1m%
//nPos = fileAccessI.write (b,0,nRead); ( d8rfet
} `P*PCiZos
catch(Exception e){e.printStackTrace ();} v +?'/Q%
} GRgpy
} 17ynFHMd,
J>0RN/38o
pf&SIG
//打印回应的头信息 xwijCFI*
public void logResponseHead(HttpURLConnection con) '^:q|h
{ uHt@;$9A
for(int i=1;;i++) 7C@m(oK
{ *.-qbwOg
String header=con.getHeaderFieldKey(i); OV7SLf
if(header!=null) n*eqM2L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x{VUl
Utility.log(header+" : "+con.getHeaderField(header)); %cq8%RT
else 5pxw[c53#
break; ~/Kqkhq+c
} *nY$YwHB
} S^SF!k=
`{nzw$
:1!k*5
public void splitterStop() Vf$q3X
{ "Qe2U(Un
bStop = true; #\O?|bN'q
} JZ"XrS0?
4m_CPe
};~I#X
} YD;"_yH
v<]$,V]
9E
/* | Fk9ME
**FileAccess.java 8ao>]5Rs3
*//文件访问(定位，写) ztaSIMZ
package NetFox; ^ Mq8jw(2
import java.io.*; tfd!;`B
212
N8`q.;qewz
public class FileAccessI implements Serializable{ $"{I|UFC
n'<F'1SWv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b5UIX Kim
RandomAccessFile oSavedFile; g;</|Z
long nPos; pIvr*UzY
{9h`h08?z
RV6|sN[x>
public FileAccessI() throws IOException @?[}\9dW
{ >m`<AynJ
this("",0); !4fT<V(
} Y^}c+)t
A}0u-W
NS^+n4
public FileAccessI(String sName,long nPos) throws IOException 'X1/tB8*
{ qyY]: (8
oSavedFile = new RandomAccessFile(sName,"rw"); Q|W~6
this.nPos = nPos; RjG=RfB'V
oSavedFile.seek(nPos); /8s>JPXKH[
} KA]5tVQA
gib;> nuBK
ne'Y{n(8%
public synchronized int write(byte[] b,int nStart,int nLen) Jnq}SUev
{ 2~W8tv0^b2
int n = -1; |F?/L>
try{ JO|xX<#:
oSavedFile.write(b,nStart,nLen); %`^{Hh`
n = nLen; sj%\lq
} hXP'NS`iv
catch(IOException e) o<i\1<eI
{ N5@l[F7I
e.printStackTrace (); sFonc
} <FU1|
=_9grF-
4*_.m9{
return n; Z oQPvs7_
} G:!'hadw
:LX (9f
[|oOP$u
} JCZ5q9b
pq<2:F:Kl
C4t@;U=x
/* oa8xuFu(n
**SiteInfoBean.java `:;fc
*/ vI+X9C?
package NetFox; '&Tq/;Ml
Q`[J3-Q*{
Iq: G9M
public class SiteInfoBean { iig@$ i#
kZHIzU
Nmu=p~f}3`
private String sSiteURL; //Site's URL ,~qjL|9
private String sFilePath; //Saved File's Path )W$@phY(I
private String sFileName; //Saved File's Name $|!@$Aj
private int nSplitter; //Count of Splited Downloading File Uk=L?t
>iFi~)i_4y
`ouCQ]tKz
public SiteInfoBean() :,FI 6`
{//nSplitter的缺省值为5 M07==R7
//default value of nSplitter is 5 ev%}\^Vl[
this("","","",5); 8/+x1,S%
} aj@<4A=;
K6@9=_A
P)&qy .+E0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hYU4%"X
{ Y|N.R(sAs&
sSiteURL= sURL; w2o5+G=
sFilePath = sPath; ub=Bz1._
sFileName = sName; j+QE~L
this.nSplitter = nSpiltter; "2J2za
zT"W(3
!d3:`l<
} p+O,C{^f
#tQ__V
`{W>Dy
public String getSSiteURL() G}p*oz~
{ Q a8;MxK`
return sSiteURL; ,lr\XhO
} wA7^
%LeZd}v
])uhm)U@
public void setSSiteURL(String value) ;`-@L
{ k<!xOg
sSiteURL = value; -@yu 9=DT
} n>:|K0u"
I\:(`)"r
+JRPd.B"@
public String getSFilePath() -mAi7[omh
{ Ym/y2B(
return sFilePath; |sklY0?l(
} sj\kp ni
6F4OISy%3
VLs%;|`5D
public void setSFilePath(String value) ;$$.L bb8
{ 9a lMC
sFilePath = value; ;ZowC#j
} f<v:Tg.[
J}37 9
bO\E)%zp
public String getSFileName() a>XlkkX
{ $3Srr*
return sFileName; m*Q*{M_e
} bf1EMai"
"fX9bh^
m03]SF(#3
public void setSFileName(String value) 7z^\}&
{ t~@~XI5
sFileName = value; w*7BiZ{s<
} 0)T`&u3!
Ed=]RR4R
E{B=%ZNnm
public int getNSplitter() |$aTJ9 Iq:
{ NM:\T1
return nSplitter; l&4+v.zr
} -P'KpX:]hd
i#W0
'k(aZ"
public void setNSplitter(int nCount) XDcA&cM}p
{ EAi!"NJ
nSplitter = nCount; tWN hFQ'
} VQ((c:+!
} oD>j26Q
VLO!hA#
q=(.N>%
/* Y] "_}
**Utility.java ZAcH`r*
*/ #Kd^t=k
package NetFox; fKN&0N|^R
:^oF0,-qZ
"o.g}Pv
public class Utility { gV-x1s+
x]%'^7#v)
KaGG4?=V
public Utility() \6z_;
{ [[sfuJD
Rx>>0%e.
6 (@U+`
} 6~_TXy/
FG[YH5
//线程睡眠 bQFMg41*w7
public static void sleep(int nSecond) vq&u19iP
{ nNJMQb'K
try{ q" aUA_}\
Thread.sleep(nSecond); 2IGoAt>V
} X[{tD#
catch(Exception e) cun&'JOH?U
{ 7@*l2edXm+
e.printStackTrace (); E=9xiS
} ,J63?EQ3
} vOl<
~p0M|
//日志 bm:"&U*tu'
public static void log(String sMsg) VkChRzhC
{ 1>"[b8a/
System.err.println(sMsg); 9X-w5$<
} h &R1"
,|r%tNh<8$
D#I^;Xg0h
public static void log(int sMsg) u6#=<FD/}
{ 1!4-M$-
System.err.println(sMsg); ?=\&O=_ln
} 5i42o+'
} Z+G.v=2q<
y$7vJl.uS/
8:)W!tr
/* ,fa'
**TestMethod.java 2[8C?7_K0?
*/ ~Os1ir.
package NetFox; SL O~
I}S~,4
9AgTrP
public class TestMethod { CC<(V{Png
ZWH9E.uj
--}5%6
public TestMethod() [m9Iz!E
{ ///xx/weblogic60b2_win.exe %Ct^{k~1
try{ nGqD{!i<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R rtr\a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AsOkOS3
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5UgxuuP4
fileFetch.start(); sD!)=t_
} eM$NVpS3
catch(Exception e){e.printStackTrace ();} #!i&
+nj 2
3?+CP-T-j
} X' ,0vK
e2X\ll
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public static void main(String[] args) g]V_)}
{ m@Vz42g~+
new TestMethod(); @*VfG CQ(
} Z@G[\"
} $xK2M
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