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)); F{4v[WP)
} $A`m8?bY
for(int i=0;i<nEndPos.length-1;i++) dVUe!S`
{ W4,'?o
nEndPos = nStartPos[i+1]; ('{aOiSH
} CBv0fQtL
nEndPos[nEndPos.length-1] = nFileLength; PXyv);#Q`
} Ze[,0Y!u&
} ?;y-skh
HB{'MBs
i),bAU!+m
//启动子线程 'J$@~P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9GRQ^E
for(int i=0;i<nStartPos.length;i++) zn>+\
{ wBvVY3VQ^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =P%&]5ts
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q6RTH
nStartPos,nEndPos,i); ;NH^+h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vm[F~2+HX
fileSplitterFetch.start(); |dz"uIrT
} X5\xq+Ih
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xKl1DIN[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M!kSt1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @H<*|3J
nEndPos = " + nFileLength); ''(rC38
// fileSplitterFetch[nPos.length-1].start(); sQJGwZ7
m8;w7S7,j~
|Iwglb!k
//等待子线程结束 |lcp (u*u
//int count = 0; ="5D}%
//是否结束while循环 c6lCF &
boolean breakWhile = false; [_nOo`
m^0vux
F(#?-MCs
while(!bStop) $btu=_|f
{ cS'{h
write_nPos(); zPxR=0|
Utility.sleep(500); W7Y@]QMX
breakWhile = true; ggL/7I(
+ c+i u6+"
P6O\\,B1A
for(int i=0;i<nStartPos.length;i++) 6UqAs<c9
{ vJaWHC$q
if(!fileSplitterFetch.bDownOver) h=0a9vIXF
{ P%)r4+at
breakWhile = false; 6Iqy"MQuq
break; pr,,E[
} )AxD|A
} I/XSW#
if(breakWhile) FuBt`H
break; v7SYWO#
1*yxSU@uY
e6>G8d
//count++; SDC'S]{ew
//if(count>4) N[e,%heR
// siteStop(); 5 ty2e`~K
} /IG{j}
ROmmak(y8
lKw-C[
System.err.println("文件下载结束！"); B,cFvS
} 4~&3.1
catch(Exception e){e.printStackTrace ();} vUVFW'-
} y^,QM[&
x};~8lGT>t
4"k&9+>
//获得文件长度 ~f(5l.
public long getFileSize() IJ&Lk=2E]
{ W-l+%T!
int nFileLength = -1; xa@$cxt
try{ X!qK[b@Z
URL url = new URL(siteInfoBean.getSSiteURL()); o0]YDX@T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nj'5iiV`]
httpConnection.setRequestProperty("User-Agent","NetFox"); 5XUm}D$
Ga5*tWj
:Y\ ~[Y
int responseCode=httpConnection.getResponseCode(); **L&I5Hhm
if(responseCode>=400) pX{wEc6}
{ 1,%`vlYv
processErrorCode(responseCode); F5qA!jZ1]
return -2; //-2 represent access is error Q{|%kU"
} P,ueLG=
HoABo:
?UAuUFueA
String sHeader; dI ,A;.
{KNaJ/:>W
Vf&U`K
for(int i=1;;i++) D9[19,2r`
{ T2MC`s|`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )b #5rQ
//Utility.log(in.readLine()); o 2Nu@^+
sHeader=httpConnection.getHeaderFieldKey(i); [M[<'+^*
if(sHeader!=null) 8Y.qP"s
{ ?!P0UTe~
if(sHeader.equals("Content-Length")) !i)!|9e
{ v?OVhV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lG\uJxV
break; D,}bTwRb-
} &liON1GLM
} q* p
else LDc EjFK(
break; NgDhdOB
} /"8e,
} |@iM(MM[?
catch(IOException e){e.printStackTrace ();} @W>@6E
catch(Exception e){e.printStackTrace ();} =|]h-[P'
5[jcw`
.oyAi||
Utility.log(nFileLength); P|<V0 Vs.
"00j]e.
~j'D%:[+VH
return nFileLength; 1`K-f m)
} i90X0b-A
'z;(Y*jb
Xx{| [2`
//保存下载信息（文件指针位置） o>r P\
private void write_nPos() {P8d^=#q
{ 4{YA['
try{ lH4Nbluc^
output = new DataOutputStream(new FileOutputStream(tmpFile)); x(TF4W=j
output.writeInt(nStartPos.length); f?UI+TU
for(int i=0;i<nStartPos.length;i++) k9}8xpH
{ %=UD~5!G0
// output.writeLong(nPos); 9jTBLp-i#N
output.writeLong(fileSplitterFetch.nStartPos); }#FV{C]
output.writeLong(fileSplitterFetch.nEndPos); wuH*a3(
} +Ww] %`_
output.close(); MW7~=T
} * @4@eQF
catch(IOException e){e.printStackTrace ();} -`PziGl@<
catch(Exception e){e.printStackTrace ();} H%O\4V2s
} Y1-dpML
[7I bT:ph
[f_^BU&
//读取保存的下载信息（文件指针位置） O`~#X w
private void read_nPos() OJcS%-~
{ YRlfU5
try{ KEOk%'c,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +>#SNZ[
int nCount = input.readInt(); 2T&MVl!%
nStartPos = new long[nCount]; PY5&Fwjc
nEndPos = new long[nCount]; uCDe>Q4@/
for(int i=0;i<nStartPos.length;i++) jsN[Drra
{ '5BD%#[
nStartPos = input.readLong(); TmG);B}
nEndPos = input.readLong(); 7%Y`j/
} +-j-)WU?,
input.close(); [Arf!W-QG
} &>zH.6%$
catch(IOException e){e.printStackTrace ();} YCbvCw$Ob
catch(Exception e){e.printStackTrace ();} sG`x |%t
} X<L=*r^C,=
>9{?&#]x
SY+0~5E
private void processErrorCode(int nErrorCode) fkZHy|m
{ I_r@Y:5{
System.err.println("Error Code : " + nErrorCode); Me.I>7c
} s(=wG|
$X#y9<bW
<N vw*yA
//停止文件下载 Vgm'&YT
public void siteStop() IEhD5?
{ j L|6i-?!
bStop = true; = wD#H@h
for(int i=0;i<nStartPos.length;i++) /Q;wz!V$
fileSplitterFetch.splitterStop(); =-2~>B
[./FzlAs
?@ oF@AEx=
} KW .4 9
} cqG6di7#
//负责部分文件的抓取 <+k&8^:bi
**FileSplitterFetch.java EV?}oh"x
*/ H>CbMz1u
package NetFox; =Wcvb?;*
}p~2lOI
l8oaDL\f
import java.io.*; [Z$H<m{c-
import java.net.*; B7 s{yb
WQ9e~D"
fQfn7FaW_\
public class FileSplitterFetch extends Thread { (.4lsKN<
Tvx1+0Z%z
d6J/)nl
String sURL; //File URL OD8 fn
long nStartPos; //File Snippet Start Position aFTWzz
long nEndPos; //File Snippet End Position Zonjk%tC
int nThreadID; //Thread's ID ;QBS0x\f@
boolean bDownOver = false; //Downing is over : "85w#r
boolean bStop = false; //Stop identical s)E \
FileAccessI fileAccessI = null; //File Access interface }X)vktE+|
296}LW
["3dr@T9Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &&&-P\3
{ 4,)9@-|0R
this.sURL = sURL; u9! ?
this.nStartPos = nStart; ]DVr-f ~
this.nEndPos = nEnd; \qG?'Iy
nThreadID = id; bIU.C|h@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p[Po*c.b
} y#GHmHeh
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q}LDFsU
public void run() lbHgxZ
{ dbby.%
while(nStartPos < nEndPos && !bStop) QHNyH
{ ?Lg(,-:
KwL_ae6fV
zy,SL |6:
try{ Xd(^7~i
URL url = new URL(sURL); RDdnOzx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ev7.!
httpConnection.setRequestProperty("User-Agent","NetFox"); al2lC#Sy
String sProperty = "bytes="+nStartPos+"-"; xgk~%X%K
httpConnection.setRequestProperty("RANGE",sProperty); kq}byv}3I
Utility.log(sProperty); tpJA~!mG3
Q4u.v,sE
{'IO
InputStream input = httpConnection.getInputStream(); 11oNlgY&
//logResponseHead(httpConnection); kOydh(yE
r07u6OA
DB|1Sqjsn
byte[] b = new byte[1024]; ^^b'tP1>
int nRead; 7a"06Et^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PeJ#9hI~rQ
{ njs:
nStartPos += fileAccessI.write(b,0,nRead); dxX`\{E
//if(nThreadID == 1) ]hS:0QE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m4/qxm"Dx:
} ,6>3aD1w~q
=z'(FP5!0
c""&He4zp
Utility.log("Thread " + nThreadID + " is over!"); uPfz'|,
bDownOver = true; ZO<,V
//nPos = fileAccessI.write (b,0,nRead); jrQ0-D%M d
} FOk&z!xYKd
catch(Exception e){e.printStackTrace ();} Z}S[fN8
} ;E.]:Ia~
} "6jt$-?
QY;(Ny/(y
t{>K).'
//打印回应的头信息 cfIC(d
public void logResponseHead(HttpURLConnection con) =dGp&9K,fw
{ pCE GZV,d@
for(int i=1;;i++) B7f<XBU6>
{ O)q4^AE$
String header=con.getHeaderFieldKey(i); z8X7Y >+SA
if(header!=null) .y s_'F-]0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [.}qi[=n
Utility.log(header+" : "+con.getHeaderField(header)); 1$0Kvvg[
else vfkF@^D
break; _KM? ?&
} lUu0AZQmG
} <e UsMo<
,8 4|qI
]yPK}u
public void splitterStop() H,%bKl#
{ z206fF
bStop = true; `]5qIKopL
} !,`'VQw$
c]M+|R5
8$}<4 `39
} rCw4a?YS
6\7c:
Jinh#iar
/* )J 'F]s
**FileAccess.java LQ~|VRRX<
*//文件访问(定位，写) bL7Gkbs&|
package NetFox; jF?0,g
import java.io.*; liS'
Tksv7*5$
":/c|!
public class FileAccessI implements Serializable{ "pO
x"z\d,O%W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O&7.Ry m
RandomAccessFile oSavedFile; gCghWg{S
long nPos; .s<0}<Aq>
*y4g\#o.
2 ,nhs,FZ
public FileAccessI() throws IOException i*|HN"!
{ hrKeOwKHU
this("",0); Qf_N,Bq{a
} WHC/'kvF
r-T1^u
`<tRfl}qs
public FileAccessI(String sName,long nPos) throws IOException fn<dr(Dx
{ yP]>eLTSd
oSavedFile = new RandomAccessFile(sName,"rw"); /H<{p$Wd
this.nPos = nPos; HAH\#WE
oSavedFile.seek(nPos); *<^C0:i(
} j& 7>ph
;!HQ!#B
}Q`+hJ0
public synchronized int write(byte[] b,int nStart,int nLen) [x)T2sA
{ x_7$g<n
int n = -1; gxO~44"
try{ 0o8`Y
oSavedFile.write(b,nStart,nLen); 7X(2SI3m
n = nLen; ;l%xjMcU
} _`SDG5
catch(IOException e) 3rRIrrYO
{ W<q<}RSn
e.printStackTrace (); %i?
} Py*WHHO
,It0brF
"7sv@I_j
return n; BQfnoF
} ;jgf,fbM
pBAAwHD
`RY}g;
} DQ0S]:tC
ZW?h\0Hh
-9LvAV>
/* P'h39XoZ
**SiteInfoBean.java JcRxNH )<"
*/ V~PGmn[V
package NetFox; ]n4PM=hz
;C-ds
}h1BAKg
public class SiteInfoBean { {eU>E/SQ
p@78Xmu?q
UG.:D';3,
private String sSiteURL; //Site's URL v^eAQoFLhN
private String sFilePath; //Saved File's Path >C,0}lj
private String sFileName; //Saved File's Name rZ,qHM
private int nSplitter; //Count of Splited Downloading File MZ%J ]Nd
i@:^b_
-$!r+4|q
public SiteInfoBean() 2l,>x
{//nSplitter的缺省值为5 N]yT/8
//default value of nSplitter is 5 e_!h>=$%8
this("","","",5); Jm ,:6T
} FTUfJIVN(
t!wbT79/
pOK=o$1V8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;ZB=@@l(
{ Vw;iE=L
sSiteURL= sURL; < R"Y^]P=
sFilePath = sPath; PoZ$3V$(Lz
sFileName = sName; fKEDe>B5
this.nSplitter = nSpiltter; %(s|
=X(N+(1~
'sAkrl8kt
} ty!DMg#
6\l F
t_ CMsp
public String getSSiteURL() #>_t[9;
{ .;31G0<w2
return sSiteURL; u"5/QB{
} J4]"@0?6
Hd4 ~v0eS
iM!V4Wih6
public void setSSiteURL(String value) 7r,GdP.
{ V@+sNM
sSiteURL = value; jA8Bmwt;w
} H`<u2fo|p
1<h@^s;
&5jc &CS
public String getSFilePath() I!F&8B+|
{ s]yZ<uA
return sFilePath; 4qDa:D"5
} &pl)E$Y
<.g)?nj1
<Y /3U
public void setSFilePath(String value) xe OfofC(l
{ @/aJi6d"^E
sFilePath = value; bHq.3;
} ,6y.wNb:F
qKXg'1#E)
1grcCL q
public String getSFileName() Y".?j5f?
{ Mb_"M7
return sFileName; q:F6MW
} Bph(\= W
rG-x 3>b
bPV}T`
public void setSFileName(String value) e8SAjl"}
{ Q$Qr)mcC
sFileName = value; :V"e+I
} xz:
xNY&*jI
|1kA6/
public int getNSplitter() hRKJKQ@7
{ -= c&K&
return nSplitter; S]E|a@kD3
} R(> oyxA[F
5 3+C;]J
ixy:S1pI
public void setNSplitter(int nCount) o7tlkSZ
{ ,*Wh{)
nSplitter = nCount; m k~F@
} 0I)eYksh
} MG&vduu
Cjt].XR@
R8.@5g_
/* mr>E'd.'
**Utility.java r"L:Mu
*/ 1"A"AMZf
package NetFox; T*k{^=6"!
s Wj:m)
{o'(_.{
public class Utility { ]q#"8=
m{*_%tjN0
O~Jf"Ht
public Utility() 9;gy38.3
{ 5[6{o$I
4M$"0}O;[h
^~B#r#
} WYvcN8F
f#38QP-T
//线程睡眠 <@>icDFEHn
public static void sleep(int nSecond) gBgaVG
{ G #$r)S
try{ tR=1.M96Y
Thread.sleep(nSecond); =?M{B1;H
} ?YFSK
catch(Exception e) o|KmKC n>
{ Fyz1LOH[X
e.printStackTrace (); FLumI-se!
} 8N<2RT8W
} .4z_ohe
^6UE/4x!y
//日志 pmUC4=&e
public static void log(String sMsg) ],<pZ1V;
{ F6{Q1DqI
System.err.println(sMsg); 93)1
} z9Y}[pN
:2t?0YR
:y~l?0b&8
public static void log(int sMsg) nqYarHi
{ V[*<^%
System.err.println(sMsg); ~c,+)69"T
} ZB$,\|^6
} UWgPQ%}
Y4Jaw2b
sVS),9\}
/* a{I(Qh!}
**TestMethod.java (Kkqyrb
*/ #9(iu S+BU
package NetFox; ;|vn;s/
GQ9H>Ssz
)"bP]t^_
public class TestMethod { B%co`0$
r+k~%5Ff~
qaBL
public TestMethod() DRu#vC
{ ///xx/weblogic60b2_win.exe Gd2t^tc
try{ b9l%5a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !5zj+N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k+u L^teyS
SiteFileFetch fileFetch = new SiteFileFetch(bean); x]"N:t
fileFetch.start(); L# .vbf
} Ap(>mUs!i
catch(Exception e){e.printStackTrace ();} Qv;^nj{\qV
3r2e_?m
F`f8q\Fc
} rV/! VJ6x
%\!3tN
4:s!mHcz
public static void main(String[] args) .Nd_p{
{ $0~_)$i:
new TestMethod(); ^,fMs:
} u3vw[k
} mm`yu$9gbP
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