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)); 1=X"|`<!
} B{+ Ra
for(int i=0;i<nEndPos.length-1;i++) 70&]nb6f
{ ]\_T
nEndPos = nStartPos[i+1]; en6oFPG
} L4,Ke
nEndPos[nEndPos.length-1] = nFileLength; 5{uK;Vxse
} ' y9yx[P
} Md4JaFA(
b!ea(D!:
6bW:&IPQ;
//启动子线程 r=3knCEWK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @JL+xfz
for(int i=0;i<nStartPos.length;i++) Q4JvFy0'
{ J}vxK H#=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =P.m5e<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \dIQhF%%2
nStartPos,nEndPos,i); r$Z_Kwe.|&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _^)<d$R<
fileSplitterFetch.start(); H!NyM}jsr
} / NlT[@T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aj:B+}1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &@MiR8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j7M[]/|
nEndPos = " + nFileLength); &]?X"K
// fileSplitterFetch[nPos.length-1].start(); G$"$k=[
P95A_(T=[
:W\xZ
//等待子线程结束 @Ja8~5:
//int count = 0; VY9|8g/
//是否结束while循环 u< ,c
boolean breakWhile = false; G`HL^/Z*
IO\>U(:vx
W l+[{#
while(!bStop) VYZkHjj)2i
{ #+- /0{HT
write_nPos(); Aey*n=V4#F
Utility.sleep(500); Evn=3Tw
breakWhile = true; AShnCL8uR
a|x1aN0
{G D<s))
for(int i=0;i<nStartPos.length;i++) 1*"t-+|
{ DGwN*>X
if(!fileSplitterFetch.bDownOver) u(s/4Lu
{ :OVre*j
breakWhile = false; =a<};X
break; !Bv"S0
} WD^!G;}
} '>]9efJA
if(breakWhile) 8SGFzb! h
break; WYb\vm=r
RG)!v6
@KhDQ0v]5
//count++; (,gpR4O[
//if(count>4) >*PZ&"}M
// siteStop(); \+cU}
} f(h nomn
G Uf[Dz
gqje]Zc<
System.err.println("文件下载结束！"); lKMOsr@l
} ;:a>#{N
catch(Exception e){e.printStackTrace ();} @k!J}O K
} ]mN'Qoc
5;5DEMe
]i-peBxw
//获得文件长度 `;ofQz4
public long getFileSize() rSUarfZ<
{ GN4'LU
int nFileLength = -1; 3f2%+2Zjt,
try{ N;9m&)@JR'
URL url = new URL(siteInfoBean.getSSiteURL()); #-_';Er\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) /kf
httpConnection.setRequestProperty("User-Agent","NetFox"); ' {L5 3cH=
G $TLWfm
cu4&*{
int responseCode=httpConnection.getResponseCode(); 8X@p?43
if(responseCode>=400) \G?GX
{ 7|IOn5
processErrorCode(responseCode); *Op;].>E
return -2; //-2 represent access is error fAu^eS%>7
} @?$x
brA\Fp^
3iHUG^sLW
String sHeader; R&cOhUj22J
37hs/=x
R#ABda9
for(int i=1;;i++) JC~L!)f
{ j9@7\N<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0,a;N%K-
//Utility.log(in.readLine()); R^PPgE6!$
sHeader=httpConnection.getHeaderFieldKey(i); gAA2S5th
if(sHeader!=null) 8,Jjv*
{ v+NdO$o
if(sHeader.equals("Content-Length")) T[}A7a6g_
{ %T hY6y(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]xlV;m
break; 4!pMZ<$3
} h01 HX
} Fb&Xy{kt1
else N02X*NC
break; 0j^QY6
} :Yi1#
} ^tS{a*Yn
catch(IOException e){e.printStackTrace ();} Z*EK56.b
catch(Exception e){e.printStackTrace ();} I%]~]a
jN\} l|;q
'u6T^YS
Utility.log(nFileLength); 3BuG_ild
_d#1muZ?p|
gOpi>
return nFileLength; v+. n9
} /;7\HZ$@/
'D ,efTq
3;@/`Z_\lt
//保存下载信息（文件指针位置） 'OIOl
private void write_nPos() S+^*rw
{ >wz&{9ni
try{ G%{J.J41F
output = new DataOutputStream(new FileOutputStream(tmpFile)); >h^CC*&'pw
output.writeInt(nStartPos.length); u^DfRd&P0
for(int i=0;i<nStartPos.length;i++) LUGyc( h
{ hk =nXv2M
// output.writeLong(nPos); D#ZzhHHP
output.writeLong(fileSplitterFetch.nStartPos); {:U zW\5l)
output.writeLong(fileSplitterFetch.nEndPos); O)y|G%O
} J<g$hk
output.close(); k8!|WqfP
} #wXq'yi
catch(IOException e){e.printStackTrace ();} qPEtMvL #
catch(Exception e){e.printStackTrace ();} E+LAE/v@
} \qx$h!<
YP*EDb?f
D=hy[sDBw
//读取保存的下载信息（文件指针位置） Y$3 &?LA
private void read_nPos() !c}?u_Z/
{ .<0|V
try{ ]ZV.@%+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v6Vieo=
int nCount = input.readInt(); J!O{.v
nStartPos = new long[nCount]; a$0,T_wD
nEndPos = new long[nCount]; Gwyjie9t
for(int i=0;i<nStartPos.length;i++) [D!-~]5
{ KIyhvY~
nStartPos = input.readLong(); Gk<M@d^hQ
nEndPos = input.readLong(); h^yLmRL
} =Q\z*.5j.
input.close(); Rra3)i`*
} =L,s6J8_'
catch(IOException e){e.printStackTrace ();} i2. +E&3v
catch(Exception e){e.printStackTrace ();} #2`ST=#
} c1!0Z28
}I3 ZNd
*C/bf)w
private void processErrorCode(int nErrorCode) ,t"?~Hl".
{ 8|Wu8z--
System.err.println("Error Code : " + nErrorCode); d']CBoK
} <>=A6
:{:R5d(_I
%sd1`1In
//停止文件下载 O*;$))<wX
public void siteStop() ZDMv8BP7
{ Ri[ v(Zf
bStop = true; DRp h?V\
for(int i=0;i<nStartPos.length;i++) Mnj\t3:
fileSplitterFetch.splitterStop(); iLQFce7d|&
L#t^:%
$ z4JUr!m
} 5k%GjT
} <OX_6d*@
//负责部分文件的抓取 ( (.b&
**FileSplitterFetch.java OvL@@SX |
*/ K fM6(f:
package NetFox; Gi=sJV
qDG{hvl[1r
Pu|PIdu!08
import java.io.*; (R'GrN>
import java.net.*; }>q%##<n
XH^X4W
\fX0&l;T9\
public class FileSplitterFetch extends Thread { K1S:P( S
gu~JB
rM?O2n
String sURL; //File URL :6}Zo
long nStartPos; //File Snippet Start Position 9'$\GN{0
long nEndPos; //File Snippet End Position 0m3:!#\
int nThreadID; //Thread's ID mP!=&u fcU
boolean bDownOver = false; //Downing is over LS"_-4I}
boolean bStop = false; //Stop identical s5`CV$bz
FileAccessI fileAccessI = null; //File Access interface @ Sq =q=S
prIPPeMdz
a ~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }s9eRmJs
{ V-1H(wRu
this.sURL = sURL; 5|nT5oS
this.nStartPos = nStart; n(}cK@
this.nEndPos = nEnd; %-lilo
nThreadID = id; bD2):U*Fzo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &ikPa,A
} D^_]x51>
B//2R)HS
p`+=) n
public void run() [8kufMY|
{ 'P AIh*qA
while(nStartPos < nEndPos && !bStop) VVd9VGvh
{ [6ycs[{!
OON]E3yy
*KMW6dg;
try{ =,MX%-2
URL url = new URL(sURL); QL].)Vgf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jDO"?@+
httpConnection.setRequestProperty("User-Agent","NetFox"); [:hTwBRF
String sProperty = "bytes="+nStartPos+"-"; 4!vovt{
httpConnection.setRequestProperty("RANGE",sProperty); 4](jV}Hg
Utility.log(sProperty); =&_Y=>rA]0
}s@ i
\!51I./Q/
InputStream input = httpConnection.getInputStream(); /8cfdP Ba
//logResponseHead(httpConnection); GbXa=* <-<
l:@`.'-=
vtByCu5
byte[] b = new byte[1024]; &c AFKYt
int nRead; EDDld6O,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @K=:f
{ 8|cQW-L
nStartPos += fileAccessI.write(b,0,nRead); KUV(vAY,
//if(nThreadID == 1) pW7#&@AR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TPBL|^3K
} Zra P\?
pu"m(9
ln1QY"g
Utility.log("Thread " + nThreadID + " is over!"); M?gc&2Y
bDownOver = true; G7qB
//nPos = fileAccessI.write (b,0,nRead); 3D}rxI8N
} Ii.?| u
catch(Exception e){e.printStackTrace ();} PHxU6UPqy
} FQlYCb
} C:9a$
e{Y8m Xu
Jan~Rran
//打印回应的头信息 hZwbYvu
public void logResponseHead(HttpURLConnection con) r|ID]}w
{ }J^+66{
for(int i=1;;i++) ZRy'lW
{ >)j`Q1Qc\
String header=con.getHeaderFieldKey(i); w/oXFs&FK
if(header!=null) s7Z+--I)L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _{C =d3
Utility.log(header+" : "+con.getHeaderField(header)); n40&4n
else P\rA>ZY
break; F97HFt6{
} )c<X.4
} 3oQ?VP
v =]!Po&Q-
/8O;Q~a
public void splitterStop() UhX)?'J
{ Zk+c9,q
bStop = true; %wQE lkB
} qS!U1R?s
fG,)`[eD!_
m\.(-
} 2:jWO_V@
Z.%0yS_T
1$S`>M%a
/* 2v\<MrL
**FileAccess.java lD-HQd
*//文件访问(定位，写) s#p\ r
package NetFox; Qn!KL0w
import java.io.*; khb/"VYd
Gl6M(<f\5
VBN=xg}
public class FileAccessI implements Serializable{ <hBd #J
dcH@$D@~S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^Z>Nbzr{
RandomAccessFile oSavedFile; {3qlx1w
long nPos; &~&oB;uR
cna/?V
8#ZF<BY
public FileAccessI() throws IOException `gX$N1(
{ nrM_ay
this("",0); 9>-]*7
} .jv#<"DW
?3yrX_Qm{
^|lw~F
public FileAccessI(String sName,long nPos) throws IOException O!k C
{ kKs}E| T
oSavedFile = new RandomAccessFile(sName,"rw"); c\.7Z=D
this.nPos = nPos; lcR1FbJ2'
oSavedFile.seek(nPos); @=6*]:p2.
} #/ HQ?3h]
/=[hRn@)A
{'UK>S
public synchronized int write(byte[] b,int nStart,int nLen) 5_[we1$P
{ S7h?tR*u
int n = -1; FT Ytf4t
try{ % pQi}x
oSavedFile.write(b,nStart,nLen); Zq"
n = nLen; &Vy.)0
} ~F.kgX
catch(IOException e) ZkqZO#nq C
{ Zv5vYe9Ow
e.printStackTrace (); giHWC%/
} zrL+:/t
q^eLbivVE
nC5]IYL|
return n; VLcwBdo
} ly::?
6=p!`DOd
h'"~t#r
} hH~GH'dnaE
62 9g_P)
=Bos>;dl
/* 7{Zs"d{s
**SiteInfoBean.java !7n`-#)
*/ *:Uq ;)*
package NetFox; 4G'-"u^g
z#GrwE,r
=h\uC).t&
public class SiteInfoBean { yqKSaPRA
ziXI$B4-
N gagzsJ=
private String sSiteURL; //Site's URL dYZB> OS
private String sFilePath; //Saved File's Path i}/Het+(
private String sFileName; //Saved File's Name }t0JI3
private int nSplitter; //Count of Splited Downloading File ddwokXx (
B)BR y%
|e91KmiqJ
public SiteInfoBean() Ge ?Q)N
{//nSplitter的缺省值为5 |F49<7XB[~
//default value of nSplitter is 5 fS]Z`U"
this("","","",5); /kV5~i<1S
} qZ%0p*P#_
yJ*g ;
m1DrT>oN'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xm0(U0 >
{ ~Z}DN*S
sSiteURL= sURL; V?- ]ZkI
sFilePath = sPath; num2HtU&%
sFileName = sName; oC}2 Z{
this.nSplitter = nSpiltter; c!a1@G
_Jn@+NoO
Rnw v/)
} %+oV-o\ #A
C1x(4&h
kZ'wXtBYe
public String getSSiteURL() S\sy] 1*?$
{ <_yy0G
return sSiteURL; Tbj}04;I
} q{XeRQ'/
?nwg.&P
qT^0 %O:
public void setSSiteURL(String value) "4L_BJZ
{ y3ST0=>j}
sSiteURL = value; (!%w
} ,[[Xo;q
$pajE^d4V
3il/{bgM
public String getSFilePath() 0Om<+]).R
{ /0r6/ _5-.
return sFilePath; +8.1cDEH\
} ~iJ@x;`
#:=*n(GT
ok{ F=z
public void setSFilePath(String value) ?~X^YxWsY
{ s1J(-O
sFilePath = value; GHFYIor
} z}-8pDD'
p/gf
0Vj!'=Ntv
public String getSFileName() p:xVi0
{ w|:ev_c|
return sFileName; #kp+e)F
} %UB+N8x`a
+TN*6V{D
Bp/25jy
public void setSFileName(String value) #zg"E<
{ (H-kWT
sFileName = value; BOme`0A
} 3-gy)5.xe
SHQgI<D7
z q@"qnr
public int getNSplitter() 9`Xr7gmQf
{ DI=?{A
return nSplitter; %JuT'7VB
} W];l[D<S*
YXIAVSnr
-o+; e3#
public void setNSplitter(int nCount) ASa)xf9
{ [#2X
nSplitter = nCount; 5>>JQ2'W
} s} oD?h:T3
} `%$+rbo~
sV`p3L8pl
i!+0''i{#
/* <+: PTG/('
**Utility.java Xj$'i/=-+c
*/ R_Uy.0=4
package NetFox; Sz>Lbs
Hli22~7T:
HxNoV.q
public class Utility { !Aw.)<teW
R T/)<RT9
]%+T+zg(Y
public Utility() beFD}`
{ G=&nwSL
b5W(}ka+
8b< 'jft
} !fG}<6&i
.QB)Y* z
//线程睡眠 8UXtIuQ
public static void sleep(int nSecond) "B0I$`~wu
{ \I7,1I
try{ FvDi4[F#
Thread.sleep(nSecond); 2I{kLN1TY
} U3|9a8^H
catch(Exception e) ^<Zye>KO
{ $t.M`:G
e.printStackTrace (); Zo@
} N]&:xd5
} `{xKU8j^
"f>`ZFp^
//日志 NZZc[P
public static void log(String sMsg) !mK}Rim~
{ y0,>_MS
System.err.println(sMsg); MbXtmQ%C8
} `( _N9.>B
`W2 o~r*&
xo#K_"E
public static void log(int sMsg) B[fbPrM
{ )^m"fQ+
System.err.println(sMsg); R+tQvxp#
} Rln% Y
} eDsc_5I
0+Q;a
URj2 evYW
/* K$5mDScoJ
**TestMethod.java sv2XD}}
*/ Vj6w7hz
package NetFox; l]S%k&
?fQ8Ff
~r&+18Z;
public class TestMethod { 7-d.eNQl
o`{^ptu1q
apWv+A
public TestMethod() 64t:
{ ///xx/weblogic60b2_win.exe fiW2m=h_
try{ a=M/0N{!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !G;|~|fMV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]4]AcJj
SiteFileFetch fileFetch = new SiteFileFetch(bean); =L*-2cE6#
fileFetch.start(); Z*YS7 ~
} n,`j~.l-=>
catch(Exception e){e.printStackTrace ();} 3Hf_!C=g
_xr@dK<
U$LI~XZM
} <J-.,:
+f'@
ebhV;Q.
public static void main(String[] args) zh9B8r)C
{ SDko#
new TestMethod(); `Af5%m[
} X08[,P#I
} GB}!7W"
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