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)); 5?O"N
} ?|33Np)
for(int i=0;i<nEndPos.length-1;i++) !>tXib]:
{ 4aRYz\yT=
nEndPos = nStartPos[i+1]; ObCwWj^qO
} ivm.ng[
nEndPos[nEndPos.length-1] = nFileLength; +G~b-}
} Cur)|
} $lqV(s
S:d`z'
5~kf:U%~
//启动子线程 g#AA.@/Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 25(\'484>
for(int i=0;i<nStartPos.length;i++) (xTHin$
{ ,]d}pJ}PX`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /~yqZD<O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 09"~<W8
nStartPos,nEndPos,i); ,wV2ZEW}e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2{&" 3dq
fileSplitterFetch.start(); li{_biey}
} 5Z:HCp-aG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^j` vk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @sDd:>t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", JG_7G=~
nEndPos = " + nFileLength); Cfj*[i4
// fileSplitterFetch[nPos.length-1].start(); (|x->a
4k#6)e
=4I361oMf
//等待子线程结束 , ^nUi c
//int count = 0; Wp'\NFe8
//是否结束while循环 BYY>;>V
boolean breakWhile = false; ;2iZX=P`n
O[]+v
HCu1vjU(]
while(!bStop) +bSv-i-
{ 2PC4EjkC
write_nPos(); ``SjALf
Utility.sleep(500); w+}dm^X
breakWhile = true; V7^?jck
eAqQ~)8^
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for(int i=0;i<nStartPos.length;i++) :!/}*B
{ 'W#<8eJo
if(!fileSplitterFetch.bDownOver) ]D%[GO//!
{ +LyhF2
breakWhile = false; +n:#Uf)
break; 2P|-V};9
} X#o:-FKf
} oqE -q\!H
if(breakWhile) BgRiJFa.d[
break; '%MIG88
yT>T Vq/e
KyDBCCOv
//count++; \-B>']:R4
//if(count>4) Ax\Fg 5
// siteStop(); 7#&sG
} 52~k:"c
#Y:/^Q$_qS
LU]~d<i99
System.err.println("文件下载结束！"); *iR`mZb
} 6nDx;x&Q
catch(Exception e){e.printStackTrace ();} ,lUo@+
} LgaJp_d>9*
*qqFIp^
#:yZJS9f9
//获得文件长度 &#;,P:.'
public long getFileSize() {tMD*?C[6
{ X4TUi8ht!]
int nFileLength = -1; _#+9)*A
try{ L`!sV-.
URL url = new URL(siteInfoBean.getSSiteURL()); -(2-zznZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OlK2<<
httpConnection.setRequestProperty("User-Agent","NetFox"); $D89|sy
F,W(H@ ~x
9W8Dp?:
int responseCode=httpConnection.getResponseCode(); aT0 y
if(responseCode>=400) 4S=lO?\"A
{ 94R+S-|P
processErrorCode(responseCode); [brrziZ
return -2; //-2 represent access is error ~% c->\Q
} '=2t(@aC
\<8!b{F
cnsGP*w
String sHeader; @Q^;qMy
hi=U
`Ctj]t
for(int i=1;;i++) ]+Vcuzq/
{ aZ^lI 6@+4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mc8^{br61
//Utility.log(in.readLine()); MnQ_]cC
sHeader=httpConnection.getHeaderFieldKey(i); &qC>*X.
if(sHeader!=null) s6egd%r
{ vuAjAeKm
if(sHeader.equals("Content-Length")) . FruI#99
{ bcYz?o6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $_VD@YlAp
break; I,[EL{fz
} +~@Y#>+./l
} ..t=Y#
else 2V]2jxOQ
break; f[RnL#*xJU
} 3LmHH =
} S]N4o'K}q
catch(IOException e){e.printStackTrace ();} phdN9<Z
catch(Exception e){e.printStackTrace ();} Ef!F;De)A
J]UHq$B
G$j8I~E@
Utility.log(nFileLength); .DQ]q o]OG
2S;zze7)
e=_hfOUC
return nFileLength; B]vj1m`9
} 5"Yw$DB9
hD*?\bBs0
X]!@xlwF\
//保存下载信息（文件指针位置） 9V&LJhDQ
private void write_nPos() 3XRG"
{ 4Y!v$r
try{ *E]\l+]J
output = new DataOutputStream(new FileOutputStream(tmpFile)); b$`O|S
output.writeInt(nStartPos.length); `FwAlYJK
for(int i=0;i<nStartPos.length;i++) mAzW'Q4D
{ { SfU!
// output.writeLong(nPos); R32d(2%5K
output.writeLong(fileSplitterFetch.nStartPos); H]e 2d|
output.writeLong(fileSplitterFetch.nEndPos); |#wz)=mD
} S6mmk&n
output.close(); D\R^*k@V
} AMdS+(J
catch(IOException e){e.printStackTrace ();} 4Z] 35*
catch(Exception e){e.printStackTrace ();} S\A[Z&k0
} J^:~#`8
*QG;KJ%
A=K1T]o
//读取保存的下载信息（文件指针位置） AqkK`iJ#
private void read_nPos() `2PT 8UM
{ r.^&%D
try{ .Dm{mV@*T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -+>am?
int nCount = input.readInt(); 67x^{u7
nStartPos = new long[nCount]; keOW{:^i
nEndPos = new long[nCount]; '_)tR;s
for(int i=0;i<nStartPos.length;i++) @Hh"Y1B
{ JyO lVs<T
nStartPos = input.readLong(); 7Cf(y'w^
nEndPos = input.readLong(); %Qq)=J<H;
} ;>N ~,Q
input.close(); =HHg:"
} c29Z1Zs2)
catch(IOException e){e.printStackTrace ();} /3]|B%W9
catch(Exception e){e.printStackTrace ();} Ysu/7o4
} 7krA+/Qr(
IJ;*N
sLIP|i
private void processErrorCode(int nErrorCode) -e>)yM `i
{ 0 ,-b %X
System.err.println("Error Code : " + nErrorCode); Vi WgX.
} k#xpY!'7
sA}R!
gN~y6c:N
//停止文件下载 EB<q.
public void siteStop() S!_?# ^t
{ K5&C}Ey1
bStop = true; B:cOcd?p
for(int i=0;i<nStartPos.length;i++) c ?XUb[
fileSplitterFetch.splitterStop(); h>0<@UP
Ah{pidUx
u7WM6X
} QE2^.|d{
} Bw.&3efd
//负责部分文件的抓取 WmUW i{
**FileSplitterFetch.java PDng!IQ^
*/ bq-\'h f<
package NetFox; Q%Q?q)x
uFZB8+
X>7]g670@
import java.io.*; J|S^K kC
import java.net.*; :n9~H+!
r:4IKuTR
p]Zabky
public class FileSplitterFetch extends Thread { TZNgtR{q
F t/ x5
9PK-r;2
String sURL; //File URL IQe[ CcM
long nStartPos; //File Snippet Start Position i0Q _f!j
long nEndPos; //File Snippet End Position 92VX5?Cyg
int nThreadID; //Thread's ID U^BXCu1km
boolean bDownOver = false; //Downing is over NqE7[wH
boolean bStop = false; //Stop identical wS*CcIwj
FileAccessI fileAccessI = null; //File Access interface A5<Z&Y[
Ks2%F&\cE
oh0|2IrM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5'Jh2r
{ +WN>9V0H
this.sURL = sURL; (!5}" fj
this.nStartPos = nStart; =v$s+`cP
this.nEndPos = nEnd; Sx9:$"3.X
nThreadID = id; r5fkt>HZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Zg'pSs)
} =GKYroNM
jI`To%^Y
kjC{Zr
public void run() PJ'lZu8?x
{ qbq<O %g=
while(nStartPos < nEndPos && !bStop) uf'P9MA}>
{ kJi&9
OMI!=Upz
<`j[;>O
try{ [2 w<F[
URL url = new URL(sURL); vs)I pV(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0$ 9;pzr
httpConnection.setRequestProperty("User-Agent","NetFox"); m2q;^o:J
String sProperty = "bytes="+nStartPos+"-"; ,9tbu!Pvq
httpConnection.setRequestProperty("RANGE",sProperty); :CST!+)o
Utility.log(sProperty); Xe3z6
ca3BJWY}J
^x"c0R^
InputStream input = httpConnection.getInputStream(); ]n]uN~)9
//logResponseHead(httpConnection); 8 ]06!7S}
G q:4rG|
a$zm/
byte[] b = new byte[1024]; {&}/p-S
int nRead; gLSG:7m@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QB3d7e)8>
{ >+jbMAYSq
nStartPos += fileAccessI.write(b,0,nRead); a;'E}b{`F
//if(nThreadID == 1) *- IlF]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x"llX
} 2u*h*/
[mf7>M`p]@
RnA&-\|*
Utility.log("Thread " + nThreadID + " is over!"); W^d4/]
bDownOver = true; .W@4vrp@
//nPos = fileAccessI.write (b,0,nRead); $mI:Im`s
} mB^I@oZ*
catch(Exception e){e.printStackTrace ();} $dZ>bXUw:
} 2^^'t6@
} bg1"v a#2
(O_t5<A*X
N?=qEX|R
//打印回应的头信息 mzV"G>,o
public void logResponseHead(HttpURLConnection con) 7Z`Mt9:Ht
{ V3 _b!
for(int i=1;;i++) <5ft6a2fQ
{ )`s;~_ZZ
String header=con.getHeaderFieldKey(i); Cwsoz
if(header!=null) fY%M=,t3c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Zaq#uA
Utility.log(header+" : "+con.getHeaderField(header)); .YjrV+om1
else o,CA;_
break; bQXc IIa{
} ;h,R?mU
} OC?Zw@
zr3q>]oma
YHO;IQ5
public void splitterStop() $#G6m`V
{ /zl3&~4
bStop = true; 49xp2{
} ~tg1N^]kV
=GH@.3`X
%$ir a\ sM
} @zr8%8n
;# R3k
V~J*49t&2J
/* u>,lf\Fgz
**FileAccess.java UzU-eyA
*//文件访问(定位，写) dysX
package NetFox; H5AK n*'7
import java.io.*; &Rt+LN0qB0
MfXt+c`r
Kf05<J!
public class FileAccessI implements Serializable{ aQ!9#d_D
UM4@H1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y3={NB+
RandomAccessFile oSavedFile; gro7*<
long nPos; YW8K $W
< -Hs<T|tW
hi;WFyJTu
public FileAccessI() throws IOException A$9q!Ui#d
{ |`_ <@b
this("",0); wUru1_zjO
} BGB,Gb
$xRo<,OV+
lq>*x=<
public FileAccessI(String sName,long nPos) throws IOException 0M#N=%31
{ tSEA999
oSavedFile = new RandomAccessFile(sName,"rw"); 7XUhJN3n
this.nPos = nPos; #joF{M{
oSavedFile.seek(nPos); y!7B,
} l9_m>X~
9USrgY6_
I$aXnd6)
public synchronized int write(byte[] b,int nStart,int nLen) W;fH&r)d@
{ z6p#fsD
int n = -1; ]~?S~l%
try{ ltNuLZ
oSavedFile.write(b,nStart,nLen); -/M9 vS
n = nLen; !(W[!%
} zo_k\K`{@
catch(IOException e) q$MHCq;
{ fzLANya
e.printStackTrace (); o{9?:*?7
} rumAo'T/%
tegOT]|
xh{mca>?G
return n; 5+y@ ]5&g
} {udrT"h
ov1Wr#s
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} 6e,Apj 0
)qbI{^_g
P`}$-#DF
/* _i-\mR_~
**SiteInfoBean.java l &}piC
*/ \^yXc*C
package NetFox; )i&%cyZw
+:}kZDl@ X
sjSi;S4
public class SiteInfoBean { *f{7
w"q-#,37j
>g=^,G}y
private String sSiteURL; //Site's URL n.@#rBKZ
private String sFilePath; //Saved File's Path JK[T]|G
private String sFileName; //Saved File's Name 3*G5F}7%=
private int nSplitter; //Count of Splited Downloading File N"S3N)wgd
!zU/Hq{wcK
bdCykG-
public SiteInfoBean() 9p5= _
{//nSplitter的缺省值为5 c2/"KT
//default value of nSplitter is 5 :*=Ns[Y
this("","","",5); wqcDAO(
} Ih; aBS
$Ru&>D#stK
kPWBDpzN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N5yJ'i~,M
{ |ribWCv0
sSiteURL= sURL; 'gYg~=
sFilePath = sPath; L"4]Tm>zq
sFileName = sName; %W(^6p!
this.nSplitter = nSpiltter; -=5EbNPwG
2H6:np|O
{yTpRQN~
} 00"CC
:Pc(DfkS
kY=rz&?U
public String getSSiteURL() sp^Wo7&g
{ I,]J=xi
return sSiteURL; <Kg2$lu(_`
} u >4ArtF
D'<$ g
e#1.T
public void setSSiteURL(String value) ^}hJL7O'
{ t-x[:i
sSiteURL = value; 6s5yyy=L%~
} p=H3Q?HJ}
=x1Wii$`
)J&|\m(e
public String getSFilePath() N\'TR6_,b
{ rmsQt
return sFilePath; 1&|
} g>_OuQ|c
f9a$$nb3`
0Q`&inwh
public void setSFilePath(String value) 07FT)QTE
{ V3Yd&HVWNQ
sFilePath = value; !j0_ cA
} ?,>5[Ha^?
Dm^l?Z
GB=bG%Tb
public String getSFileName() 68p R:
{ hXc}r6<B
return sFileName; @y5=J`@=
} (xu=%
NJm-%K
V9Hl1\j^
public void setSFileName(String value) F\-Si!~oOz
{ rI>LjHP
sFileName = value; ke\[wa_!6b
} t!:)L+$3
O:IQ!mzV5
#|?8~c;RWG
public int getNSplitter() Fm5Q&'`l
{ o,*=$/or
return nSplitter; </=3g>9Z
} 8SZK:VE@
A?r^V2+j
eF5;[v
public void setNSplitter(int nCount) SO_>c+Dw
{ q/x/N5HU
nSplitter = nCount; ot }6D
} I0_Ecp
} #x)8f3I
u{Ak:0G7
7 >bMzdH
/* lE'wfUb
**Utility.java Oyan9~
*/ |vz9Hs$@l
package NetFox; QD4:W"i
`[Sl1saZ$S
?oKL&I@
public class Utility { ^V.'^=l
Y{+3}drJE
G "brT5:
public Utility() RG1\=J$:E
{ \=fh-c(J,
x*q35K^PE
qrE0H
} b 4OnZ;FI
bLlH//ZRH
//线程睡眠 (O0byu}
public static void sleep(int nSecond) t^U^Tr
{ gr+Pl>C{
try{ BIj
Thread.sleep(nSecond); r6 }_H?j
} 30d#Lq
catch(Exception e) H+x#gK2l
{ vQHpf>o
e.printStackTrace (); D/:3RZF
} VB"(9O]
} ="(>>C1-
x0<^<D&Q
//日志 .iT4-
public static void log(String sMsg) Hi8Y6|y$D
{ fRNP#pi0u
System.err.println(sMsg); DFy1 bg
} -Qb0:]sV#
-_>.f(1
l"\uf(0K
public static void log(int sMsg) H~Uq?!=b
{ h<NRE0-
System.err.println(sMsg); [z+x"9l0!
} C3.=GRg~l
} 4B$bj`h
P)1EA;
3;Hd2 ;G
/* 3Gd|YRtk
**TestMethod.java SqqDV)Uih1
*/ zlkWU
package NetFox; +c?ie4
5^2TfG9
yVYkuO
public class TestMethod { iZC`z }
FL&dv
SQ<f
public TestMethod() a}yR p
{ ///xx/weblogic60b2_win.exe }]GbUC!Zb
try{ q+%!<]7X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yxqj -
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); veO?k.u(
SiteFileFetch fileFetch = new SiteFileFetch(bean); OG}KqG!n
fileFetch.start(); ]]y[t|6
} (9'be\
catch(Exception e){e.printStackTrace ();} 6t$N78U
w4A#>;Qu*
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} H:MUNc8i
{aIZFe}B
8Fx]koP.
public static void main(String[] args) k=|K|
{ 0_HJ.g!
new TestMethod(); t= *Jg/$
} iAHZ0Du
} u\3ZIb
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