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)); m[bu(qz
} AO]lXa
for(int i=0;i<nEndPos.length-1;i++) ]OrFW4tiE
{ r{TNPa6!
nEndPos = nStartPos[i+1]; x$Oz0[
} B.G!7>=
nEndPos[nEndPos.length-1] = nFileLength; f2u2Ns0Ym
} \\lC"Z#J`
} #NE^f2
"J.jmR;
Tk!b`9
//启动子线程 }dHiW:J>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u#,]>;
for(int i=0;i<nStartPos.length;i++) O.E0LCABC
{ :I$2[K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >'jM8=o*Ax
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CS{9|FNz
nStartPos,nEndPos,i); i\Vpp8<B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oTfbx+i/G
fileSplitterFetch.start(); 8$vH&HdI
} S|J8:-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bGJUu#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D1n2Z:9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OKqpc;y:D
nEndPos = " + nFileLength); PGKXzp'
// fileSplitterFetch[nPos.length-1].start(); !kcg#+s91
G8s`<:9*
YXtGuO\q
//等待子线程结束 aOHCr>po,
//int count = 0; x-pMT3m\D#
//是否结束while循环 qck/b
boolean breakWhile = false; uJ`&hX
RI(uG-Y
TUaK:*x*
while(!bStop) }$)<k
{ -!0LIr:"
write_nPos(); &~%@QC/
Utility.sleep(500); Wj:QC<5 v
breakWhile = true; a 98
(<l2 ^H
v'!Ntk
for(int i=0;i<nStartPos.length;i++) 3+-(;>>\
{ h9I)<_}R
if(!fileSplitterFetch.bDownOver) X*"Kg
{ nIjQLx
breakWhile = false; kpH;D=;
break; //Gvk|O1
} Oi0;.<kX
} JY2 F-0t)
if(breakWhile) cDiz!n*.q
break; /;rN/ot2o
'-IT@}
`I8^QcP
//count++; .A\\v6@
//if(count>4) Jg:-TK/
// siteStop(); XijLS7Aw|
} Q:O>kCDV
@vYmkF`
@q/1m~t
System.err.println("文件下载结束！"); M0SH-0T;Z
} XKX,7
catch(Exception e){e.printStackTrace ();} $NT9LtT@K
} xLI{=sL
}4]<P
io{H$ x(
//获得文件长度 BozK!"R_<
public long getFileSize() s[q4K
{ Jyci}CU3\Q
int nFileLength = -1; WrNgV@P
try{ o#P3lz
URL url = new URL(siteInfoBean.getSSiteURL()); \( <{)GpBi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .w_`d'}
httpConnection.setRequestProperty("User-Agent","NetFox"); ph?0I:eU
I#X2UQzP
J,G9m4Z7
int responseCode=httpConnection.getResponseCode(); +MZO%4
if(responseCode>=400) J7ekIQgR
{ `4.sy +2
processErrorCode(responseCode); P"h\7V,d%
return -2; //-2 represent access is error SP*JleQN
} :6$4K"^1
n&m?BuG
rm=~^eB
String sHeader; Hu9R.[u
bo;pj$eR3R
$SzCVWS
for(int i=1;;i++) @k+G Cf
{ IR dz(~CP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I?Jii8|W9
//Utility.log(in.readLine()); %HF$
sHeader=httpConnection.getHeaderFieldKey(i); '?G[T28
if(sHeader!=null) Bdq"6SK>
{ .x!7
if(sHeader.equals("Content-Length")) *_<*bhR<
{ boF4d'g"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sRyw\v-=P
break; 2Z`$
} G#n^@kc*,
} g<iwxF
else ,AbKxT f2
break; (L0hS'
} 7#9'2dI
} vYSetAdv
catch(IOException e){e.printStackTrace ();} QR5,_wJ&
catch(Exception e){e.printStackTrace ();} 5'kTe=
{1@4}R4
r$r&4dY
Utility.log(nFileLength); *2Vp4
'!fFI1s
e.}3OK
return nFileLength; 5{ 4"JO3
} YoF\MT]W
EK8E
XJJ[F|k~
//保存下载信息（文件指针位置） W\>^[c/
private void write_nPos() (]}x[F9l
{ [^U;
try{ 5S\][;u
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5"}y\
output.writeInt(nStartPos.length); Pv7f _hw
for(int i=0;i<nStartPos.length;i++) ?+ -/';
{ 5xMA~I0c
// output.writeLong(nPos); z^P* :
output.writeLong(fileSplitterFetch.nStartPos); AJ>BF.>
output.writeLong(fileSplitterFetch.nEndPos); 5y(t`Fmt
} vNC$f(cQ
output.close(); 5DkK'tCI9Z
} IYfV~+P
catch(IOException e){e.printStackTrace ();} )e|$K= D
catch(Exception e){e.printStackTrace ();} NoJnchiU
} "$~}'`(]
iJ`%yg,
%Ye)8+-
//读取保存的下载信息（文件指针位置） :jk)(=^
private void read_nPos() #gX%X~w$F
{ 6z9R1&~%
try{ YW?7*go'Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DnNt@e2|
int nCount = input.readInt(); 60hNCVq%
nStartPos = new long[nCount]; `7QvwXsH]
nEndPos = new long[nCount]; 'w`SBYQ5
for(int i=0;i<nStartPos.length;i++) 9?u9wuH
{ [Krm .)
nStartPos = input.readLong(); 'DCKD4@C/
nEndPos = input.readLong(); Mvy6"Q:
} ( oQ'4,F
input.close(); w8 ?Pb$Fe
} OwG6i|q
catch(IOException e){e.printStackTrace ();} v%H"_T
catch(Exception e){e.printStackTrace ();} *F\T}k7
} mJ0}DJiX$
ZR!cQ oV=
g(-;_j!=
private void processErrorCode(int nErrorCode) Ci]'G>F@"
{ 2YL`3cgfb
System.err.println("Error Code : " + nErrorCode); Q3'fz 9v
} 0hrCG3k.91
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r+t ,J|V
//停止文件下载 Y brx%
public void siteStop() [NHg&R H
{ d{QMST2&
bStop = true; 7))y}N:p
for(int i=0;i<nStartPos.length;i++) x`]Ofr'
fileSplitterFetch.splitterStop(); /C*~/}
N7e`6d!
&?SX4c~?u
} b->eg 8|
} lemVP'cn
//负责部分文件的抓取 h7bPAW=(
**FileSplitterFetch.java 1S+;ZMk
*/ Iq)(UfaSve
package NetFox; xLA~1ZSVJw
)HEfU31IC
ki\B!<uv
import java.io.*; ETM2p1ru0
import java.net.*; 8$\Za,)g
bAdiA2VF'
0yn[L3x7
public class FileSplitterFetch extends Thread { >eQbipn
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#":: '?,
String sURL; //File URL wAw42{M
long nStartPos; //File Snippet Start Position N5m'To]
long nEndPos; //File Snippet End Position 5gSylts8
int nThreadID; //Thread's ID #S%4?
boolean bDownOver = false; //Downing is over E_~x==cb
boolean bStop = false; //Stop identical N*Yy&[
FileAccessI fileAccessI = null; //File Access interface Vr 8:nP:
H#+\nT2m
VKy5=2&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u+m4!`
{ _l<mu?"
this.sURL = sURL; ~F;CE"3A
this.nStartPos = nStart; Kv}k*A% S
this.nEndPos = nEnd; {-HDkG' 8
nThreadID = id; @}(SR\~N]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k=?^){[We
} Jn=42Q:>
\]I
8"x9#kyU<3
public void run() (_K_`5d;QI
{ )Ob]T{GY
while(nStartPos < nEndPos && !bStop) X'f)7RbT
{ FqwIJ|ct
\ZMP_UU(
wFvT0
try{ Cc!J1)
URL url = new URL(sURL); bG(x:Py&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |H W( vA
httpConnection.setRequestProperty("User-Agent","NetFox"); @TysXx
String sProperty = "bytes="+nStartPos+"-"; )\>r-g$
httpConnection.setRequestProperty("RANGE",sProperty); je,c7ZFO
Utility.log(sProperty); +Qs!Nhsq
TiyUr [
=p q:m
InputStream input = httpConnection.getInputStream(); DVh)w}v
//logResponseHead(httpConnection); MWs~#ReZ
hk_g2g
@.gPJMA
byte[] b = new byte[1024]; F}'wH-qp
int nRead; X'x3esw w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v5T`K=qC
{ \,R!S/R#
nStartPos += fileAccessI.write(b,0,nRead); MU1E_"Z)
//if(nThreadID == 1) F;P5D<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -IU4#s
} o\4CoeG
BxdX WO
zJY']8ah
Utility.log("Thread " + nThreadID + " is over!"); w>[T&0-N
bDownOver = true; $3k "WlRG
//nPos = fileAccessI.write (b,0,nRead); n(>C'<otj
} q>-R3HB
catch(Exception e){e.printStackTrace ();} 2 z7}+lH
} t`YWwI.
} =u=Kw R
u]M\3V.
99u/fkL
//打印回应的头信息 .x-J44i@/
public void logResponseHead(HttpURLConnection con) $mpO?D J~
{ ^I`a;
for(int i=1;;i++) <7'&1=%r
{ X?/Lz;,&
String header=con.getHeaderFieldKey(i); xQU"A2{}>
if(header!=null) 3z3_7XI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .'j29 6[u
Utility.log(header+" : "+con.getHeaderField(header)); $:EG%jl
else VI_+v[Hk/
break; ] 8Tzr
} 6+3$:?
} jj,r <T
l5k?De_(x
{<K=*rrZ
public void splitterStop() 9x?'}
{ 8sg|MWSU
bStop = true; ?:igumeYX
} E'EcP4eL
gn)R^
){P^P!s$
} _ym"m,,7?
zkexei4^<
.'T40=7
/* ag8`O&+
**FileAccess.java {eQWO.C{
*//文件访问(定位，写) GeV+/^u
package NetFox; .z-UOyer
import java.io.*; UpfZi9v?W
J,5+47b1}R
6kR\xP]Kr
public class FileAccessI implements Serializable{ SK R1E];4
%e?fH.)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Td hTQ
RandomAccessFile oSavedFile; }mk>!B}=
long nPos; y=Q!-~5|fF
E\M-k\cSj
C:i|-te
public FileAccessI() throws IOException @iLIU}+
{ +,5-qm)Gh>
this("",0); % frfSGf.#
} Sh&PNJ-*
g"K>5Cb
a#[-*ou`
public FileAccessI(String sName,long nPos) throws IOException 3FNT|QF
{ |=K_F3aJ
oSavedFile = new RandomAccessFile(sName,"rw"); "2{%JFE
this.nPos = nPos; I ~$1Lu`~
oSavedFile.seek(nPos); 4W;S=#1
} (Rd$VYuf
gzdG6"
h<x4YB5Mj
public synchronized int write(byte[] b,int nStart,int nLen) wCCV2tk
{ u0 y 1
int n = -1; 2@khSWV
try{ mLyBm
oSavedFile.write(b,nStart,nLen); i9A~<
n = nLen; [4Q"#[V&9
} :O-1rD
catch(IOException e) +L%IG
{ }]6f+
e.printStackTrace (); rv7{Ow_Y
} z|N3G E(.@
rHz||jjU
M 2q"dz
return n; %,UPJn
} Vf $Dnu@}z
T .n4TmF
1^G{tlA-
} ,[!LCXp
DjLL|jF
P_Hv%g
/* ig!7BxM)<h
**SiteInfoBean.java )rtomp:X
*/ o:p *_>&
package NetFox; 1G^#q,%X_v
GJA`l8`SQ
cg{AMeW
public class SiteInfoBean { Log|%P\
w_wslN,)
iG<Som
private String sSiteURL; //Site's URL l"+Jc1\X
private String sFilePath; //Saved File's Path SA"8!soY3
private String sFileName; //Saved File's Name J'T=q/
private int nSplitter; //Count of Splited Downloading File @It>*B yB.
#& ?g %'
Jkt4@h2Q}
public SiteInfoBean() 6iA( o*'Yn
{//nSplitter的缺省值为5 "Cz<d w]D
//default value of nSplitter is 5 "TOa=Tt{,
this("","","",5); c&nh>oN
} d+fSoSjX8
,,4 GNbBC
|`/TBQz:r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .qv'6G
{ +&=?BC}L9^
sSiteURL= sURL; jN*:QI
sFilePath = sPath; 4JyM7ePND}
sFileName = sName; 8|^CK|m6*
this.nSplitter = nSpiltter; {*m?Kc7k
SPkn3D6
ipE]}0q
} {KL5GowH
, X{>
Zu*K-ep"
public String getSSiteURL() sW@krBxMv
{ s>n(`?@L
return sSiteURL; T^.Cc--c
} aM3gRp51cj
Wr?'$:
7:E!b=o#
public void setSSiteURL(String value) K%5"u'
{ e^1uVN
sSiteURL = value; r(A.<`\
} \}0-^(9zd
f58?5(Dc|
2{|$T2?e
public String getSFilePath() V ~{fB~
{ {R6HG{"IS6
return sFilePath; ;q>9W,jy
} zCaT tb|@
XzIx:J6
=n(3o$r(
public void setSFilePath(String value) TI|/u$SJ<Z
{ PJ4(}a
sFilePath = value; @~td`Z?1y
} ,E )|y4
0MF}^"R
c]k*}W3T
public String getSFileName() _QOZsEe
{ $.%rAa_H
return sFileName; AnBJ(h
} G\d$x4CVGc
I0'WOV70
3>M&D20Z
public void setSFileName(String value) !U%T&?E l
{ :iWS\G^U
sFileName = value; fh8j2S9J
} ~Ou1WnmO
,MPB/j^o5!
o+B:#@9?
public int getNSplitter() O*6n$dUj3
{ 1 T<+d5[C
return nSplitter; DL^o_61
} _f0C Y"
0pb'\lA
OPJ: XbG
public void setNSplitter(int nCount) Y$K!7Kq
{ -_OS%ARa
nSplitter = nCount; ^"\s eS
} 8)*2@-Rp
} jhgX{xc
*A'FC|\
SymwAS+
/* ,i9Byx#TN
**Utility.java Ga>uFb}W~
*/ ZzGahtx)Y
package NetFox; ym,H@~
)::>q5c
9# 4Y1LS)
public class Utility { ?tdd3ai>
m0w;8uF2UV
CbBSFKM
public Utility() e>rRTN
{ wBj-m
2|iV,uJ&
.0 )Y
} Yj|eji7y
Vgb *% I
//线程睡眠 AI vXb\wL
public static void sleep(int nSecond) 9I7\D8r
{ }GMbBZ:nKK
try{ QS.>0i/7l
Thread.sleep(nSecond); R:-JkV>e:
} 6d[_G$'nk
catch(Exception e) @:0ddb71
{ @!N-RQ&A
e.printStackTrace (); _ZB\L^j)
} Gl %3XdU
} TcTM]ixr
9h90huyKF
//日志 #m{{a]zm^
public static void log(String sMsg) 8M*PML4r
{ rPNb\Ri
System.err.println(sMsg); ^efb 5
} O%~jop7#6
`vG,}Pt]
d,vNem-Z*L
public static void log(int sMsg) r[(xjn
{ Lf([dE1
System.err.println(sMsg); G0 J4O!3
} c !ZM
} yq-=],h
HW4.zw
>Iewx Gb>
/* ,Y?sfp
**TestMethod.java % }|cb7l
*/ yH 9!GS#
package NetFox; LTV{{Z+
ZoB*0H-
@$"J|s3M
public class TestMethod { mffn//QS
NgCuFL(Ic
XY.5Rno4
public TestMethod() @RFs/'
{ ///xx/weblogic60b2_win.exe \I-#1M
try{ uJHu>M}~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ne61}F"E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -!;l~#K=
SiteFileFetch fileFetch = new SiteFileFetch(bean); G&xo1K]
fileFetch.start(); hv6@Jr3
} _Y=2/*y^
catch(Exception e){e.printStackTrace ();} GuZ( &G6*
4H5pr
jN-vY<?h]
} P7ph}mB
u<q :$
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public static void main(String[] args) +;g{$da5
{ JjpRHw8\
new TestMethod(); "\Egs)\
} )k&a}u5y
} \~d";~Y`
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