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)); 3&7$N#v
} nnBl:p>< k
for(int i=0;i<nEndPos.length-1;i++) qJLtqv
{ 5Y(f7,JX
nEndPos = nStartPos[i+1]; qY%{c-aMA
} 9 e0Oj3!B
nEndPos[nEndPos.length-1] = nFileLength; ompkDl\E
} IQQWp@w#8
} "P{T]
^n8r mh_%
zIgD R
//启动子线程 J(%kcueb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |T^c(RpOE
for(int i=0;i<nStartPos.length;i++) R{A$hnhW6
{ %SD=3UK6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %2TjG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XV*uu "F
nStartPos,nEndPos,i); tS&rR0<OW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d=8q/]_p
fileSplitterFetch.start(); +)l6%QKcW
} oN " /w~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gTwxmp.,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {h *Pkn1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m\?H <o0
nEndPos = " + nFileLength); Jp]eFaqp
// fileSplitterFetch[nPos.length-1].start(); l]v>PIh~N
Rjz~n38.
KsBi<wY
//等待子线程结束 Z4@GcdZ
//int count = 0; *WpDavovyB
//是否结束while循环 E0a &1j
boolean breakWhile = false; s6J`i&uu
8^%Nl `_2B
isR|K9qf^
while(!bStop) '{xPdN
{ #iAEcC0k5
write_nPos(); q+Cq&|4 ?2
Utility.sleep(500); o$_,2$>mn
breakWhile = true; }0?\H)/edP
L.) 0!1
+$H`/^a.
for(int i=0;i<nStartPos.length;i++) QL_9a,R'r
{ O6$d@r;EK]
if(!fileSplitterFetch.bDownOver) NM_Xy<.~E
{ m6oaO9"K
breakWhile = false; l gzA) (
break; dy^zOqc
} BR [3i}Ud
} +>wBGVvS
if(breakWhile) FOx&'dH%@
break; O$,MdhyXC
2RC|u?+@
P\R#!+FgW8
//count++; KWH l+pL
//if(count>4) q:/<^|
// siteStop(); 26Jb{o9Z<
} .y~vn[qN
Z&E!m
.#[==
System.err.println("文件下载结束！"); bI"_hvcFp
} kL1StF#p
catch(Exception e){e.printStackTrace ();} v8!Ts"
} Wy`ve~y
:AM5EO
rW(<[2vg
//获得文件长度 7r4|>F
public long getFileSize() YXr"
{ nVt,= ?_ U
int nFileLength = -1; cq,0?2R`t
try{ c;dMXv
URL url = new URL(siteInfoBean.getSSiteURL()); e=m=IVY#W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BQfq]ti
httpConnection.setRequestProperty("User-Agent","NetFox"); t/TWLhx/
A\v(!yg
W dNOE;R
int responseCode=httpConnection.getResponseCode(); ,_(AiQK
if(responseCode>=400) w( ^
{ efu'PfZ`&
processErrorCode(responseCode); nW*D
return -2; //-2 represent access is error 3/i_?G
} nF!6
`oq][|
b,Vg3BS
String sHeader; 3</gK$f2
H${5pY_M
gL:Vj%c
for(int i=1;;i++) kED1s's
{ ^Voi4;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B<" `<oG@|
//Utility.log(in.readLine()); BrO" _
sHeader=httpConnection.getHeaderFieldKey(i); _^5OoE"}!
if(sHeader!=null) gx',~
{ p2/Pj)2
if(sHeader.equals("Content-Length")) y]e[fZ`L
{ R]! [h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (6Tvu5*4U
break; 6SGV}dAx
} Oe/\@f0bLT
} RMvq\J}w!
else 2`;&Uwt
break; Z=&cBv4Fs
} f6r~Ycf,f
} p&nPzZQL(
catch(IOException e){e.printStackTrace ();} Oe["4C
catch(Exception e){e.printStackTrace ();} Fb0r(vQ^
Jb (CH4|7
>{HQ"{Q
Utility.log(nFileLength); PV\aQO.mo
UTLuzm
&xYO6_.
return nFileLength; tvlrUp
} (rfR:[JkC2
x[_SNX"
O;dtz\
//保存下载信息（文件指针位置） <n-}z[09
private void write_nPos() !Enq2
{ 3~o#1*->
try{ gZHuyp(B
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7a_tT;f;
output.writeInt(nStartPos.length); j LS<S_`
for(int i=0;i<nStartPos.length;i++) QK`5KB(k'
{ nR(v~_y[V
// output.writeLong(nPos); 5Y(<T~
output.writeLong(fileSplitterFetch.nStartPos); <(c_[o/
output.writeLong(fileSplitterFetch.nEndPos); 5mYX#//:
} o<8('j
output.close(); e>] gCa
} <1%(%KdN[
catch(IOException e){e.printStackTrace ();} Z.l4<
catch(Exception e){e.printStackTrace ();} };Oyv7D+b
} f)x(sk
aJ/}ID
E;tEmGf6F
//读取保存的下载信息（文件指针位置） V*<`!w
private void read_nPos() fFYfb4o
{ y<5RV>"Vg
try{ $~+(si2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !ay:h Iv
int nCount = input.readInt(); [(rT,31cW
nStartPos = new long[nCount]; `]7==c #Y
nEndPos = new long[nCount]; 2Pm[ kD4E=
for(int i=0;i<nStartPos.length;i++) Ht9QINo
{ *t%Z'IA
nStartPos = input.readLong(); =f/CBYNw@V
nEndPos = input.readLong(); 0;Oe&Y
} xk*&zAt
input.close(); S T1V
} |W#(+m
catch(IOException e){e.printStackTrace ();} 6Lc{SR
catch(Exception e){e.printStackTrace ();} [2$mo;E?
} ?`lD|~
v6C$Y+5~
e=^^TX`I
private void processErrorCode(int nErrorCode) 2Wn*J[5
{ K'_qi8Z
System.err.println("Error Code : " + nErrorCode); C==yl"w
} v8} vk]b
uo8[,'
7M/v[dwL
//停止文件下载 ZQk!Ia7
public void siteStop() M '#a.z%
{ @=sM')f&
bStop = true; i$5<>\g
for(int i=0;i<nStartPos.length;i++) OU esL9
fileSplitterFetch.splitterStop(); &.l^>#
hGy[L3{
DYDeb i6
} l@)`Q
} \47djmG-
//负责部分文件的抓取 lHUd<kEC
**FileSplitterFetch.java Gl"|t't(
*/ xwF mY'o
package NetFox; 3Cw}y55_y
dfP4SJqq
@9tzk [
import java.io.*; lQM&q
import java.net.*; :N^+!,i
zub"Ap3
@PT([1C
public class FileSplitterFetch extends Thread { B[,AR"#b
8<)ZpB,7
@V&c=8)8
String sURL; //File URL Rb!y(&>v
long nStartPos; //File Snippet Start Position ~].?8C.>*
long nEndPos; //File Snippet End Position @C|nc&E2s
int nThreadID; //Thread's ID mCyn:+
boolean bDownOver = false; //Downing is over D3B]
boolean bStop = false; //Stop identical J= [D'h
FileAccessI fileAccessI = null; //File Access interface yAiO._U
c'.XC}
lvsj4cT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bp!Jjct
{ O9C&1A|lA
this.sURL = sURL; ]h?q1
this.nStartPos = nStart; WcGg
this.nEndPos = nEnd; 4{@{VsXN
nThreadID = id; |A/H*J,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eaC%&k
} #;yxn.</
K9{RU4<
oY4^CGk=
public void run() )bWopc
{ l*?_@
while(nStartPos < nEndPos && !bStop) Z]e`bfNnI
{ lSg[7lt
W,|+Dl
FUarI5#fwF
try{ kuI~lBWI
URL url = new URL(sURL); /&c2O X|Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g#MLA5%=u
httpConnection.setRequestProperty("User-Agent","NetFox"); o1vK2V
String sProperty = "bytes="+nStartPos+"-"; 5Xf]j=_
httpConnection.setRequestProperty("RANGE",sProperty); _6SAU8M,
Utility.log(sProperty); v\[+
o_1N "o%
Gl@{y (
InputStream input = httpConnection.getInputStream(); UE{$hLI?g
//logResponseHead(httpConnection); r'`7}@H*
MkL)
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byte[] b = new byte[1024]; t/}NX[q
int nRead; ^v`naA(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $AT@r"
{ o]Xt2E
nStartPos += fileAccessI.write(b,0,nRead); zak|* _
//if(nThreadID == 1) =ecLzk"+F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |r*)U(c`
} -p>~z )
-@e2/6Oi
xeL"FzF:V
Utility.log("Thread " + nThreadID + " is over!"); S=0DQ19
bDownOver = true; b[GhI+_
//nPos = fileAccessI.write (b,0,nRead); /)T~(o|i
} Cs_&BSs
catch(Exception e){e.printStackTrace ();} >.6|\{*sG
} *E*oWb]H
} {zWR)o .=
TF%Xb>jy[
c"v75lW-J
//打印回应的头信息 mU]VFPr5
public void logResponseHead(HttpURLConnection con) [ /YuI@C,@
{ .L+XV y
for(int i=1;;i++) wk ^7/B
{ {fnx=BaG
String header=con.getHeaderFieldKey(i); c:.~%AJx
if(header!=null) ^nK<t?KS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x9,jXd
Utility.log(header+" : "+con.getHeaderField(header)); #1/~eIEY
else F#>00b{Q
break; gfs;?vP
} zGFD71=#
} i84!x%|P
MoE&)~0u&
(c>g7d<>n
public void splitterStop() W&=OtN U!
{ UrHndnqM
bStop = true; 1_<x%>zG
} 59O-"Sc[
s(nT7x+W
b,^Gj]7
} 0|RofL&o
?+))J~@t
CVWT>M<
/* +rJ6DZ
**FileAccess.java ."H;bfcL_
*//文件访问(定位，写) ~L"$(^/
package NetFox; $'%GB $.
import java.io.*; QXZyiJX}
`XhH{*Q"X
y-db CYMc
public class FileAccessI implements Serializable{ {$,\Qg
t|$jgM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (Kwqa"Hk4{
RandomAccessFile oSavedFile; ~g\~x
long nPos; aknIrblS\
&yvvea]
F)(^c
public FileAccessI() throws IOException 0eNdKE
{ %W"u4 NT7
this("",0); <@<bX
} ? Bpnnwx
ts!tv6@
%(1OjfZc
public FileAccessI(String sName,long nPos) throws IOException ~<?Zj
{ TIKkS*$
oSavedFile = new RandomAccessFile(sName,"rw"); I@MG?ZQ
this.nPos = nPos; uhh7Ft#H
oSavedFile.seek(nPos); *qwN9b/!
} Qz,2PO
c1"wS*u
=3.dgtH
public synchronized int write(byte[] b,int nStart,int nLen) wX0D^)NtF
{ UPI- j#yc
int n = -1; "5&"Ij,/
try{ ^o{{kju
oSavedFile.write(b,nStart,nLen); tL$,]I$1+
n = nLen; 0+e=s0s.
} AP=h*1udk
catch(IOException e) =P]Z"Ok
{ ^Hv&{r77
e.printStackTrace (); px<psR5
} Lw}-oE !U
=I`S7oF
=mO5~~"W+v
return n; hBjU(}\3
} &KjMw:l
#NW+t|E
Jt=->
} !+%gJiu:
[UA*We 1
Jh3
/* P |tyyjO
**SiteInfoBean.java { c#US
*/ Y(g_h:lf,]
package NetFox; CefFUqo4
TQ]gvi|m
z2iMpZ
public class SiteInfoBean { (oGYnN,2
}PBme'kP
`NNP<z+\
private String sSiteURL; //Site's URL m$p}cok#+S
private String sFilePath; //Saved File's Path E`o_R=%
private String sFileName; //Saved File's Name /_0B5,6R
private int nSplitter; //Count of Splited Downloading File iT}>a30]B
R iLl\S#
'#7k9\
public SiteInfoBean() QPVi& *8_
{//nSplitter的缺省值为5 N4vcd=uG#
//default value of nSplitter is 5 EB}B75)x
this("","","",5); a;xeHbE
} SZF 8InyF
^2~ZOP$A
Kk8wlC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8"j$=T6;W
{ c["1t1G
sSiteURL= sURL; 6Qkjr</
sFilePath = sPath; ,`bW(V
sFileName = sName; },8|9z#pyB
this.nSplitter = nSpiltter; NftnbsTmy
"z{/*uM2<
Cw,a)XB
} /x??J4r0
I _KHQ&Z*
FBXktSg
public String getSSiteURL() Mt4
{ ;j26(dH
return sSiteURL; s9ix&m
} nK;d\DO
y|| n9
R4'.QZ-x
public void setSSiteURL(String value) 3+Lwtb}XPF
{ Gd 4S7JE
sSiteURL = value; f6Y?),`
} sE?%;uBb
|HycBTN#E
OkciL]
public String getSFilePath() %unn{92)
{ lwQ!sH[M
return sFilePath; zDdo RK@
} B~I ]3f
E{T3Xwg
|KhpF1/(
public void setSFilePath(String value) {'{}@CuA2
{ mW"e
sFilePath = value; }!iopu
} -dM~3'
B&_:20^y~
TB>_#+:
public String getSFileName() aH"d~Y^
{ #`_W?-%^
return sFileName; 2U[/"JL
} >)WE3PT/O"
u.2X"
k{f1q>gd
public void setSFileName(String value) f!+d*9
{ x<l 5wh
sFileName = value; &u:U"j
} spA|[\Nl
96\FJHtZ
1|p\rHGd
public int getNSplitter() <sC(a7i1
{ fQ9af)d
return nSplitter; )zWu\JRp
} (Mfqzy
TIp\-
.uA O.<
public void setNSplitter(int nCount) e)HFI|>
{ wf ]Wm
nSplitter = nCount; s>DFAu!
} \*MZ1Q*x
} L"YQji!
<W!T+sMQj
>7WT4l)7!b
/* iX?j"=!
**Utility.java .Yk}iHcW.
*/ F7}yt
package NetFox; 7oE:]
j/Kul}Ml\*
#sU>L=
public class Utility { w?D=
A@3'I ;
'cCM[P+
public Utility() ar@,SKU'K
{ eV_",W
LiEEQ
<RxxGD
} Nn_b
t]sk[
//线程睡眠 }D1?Z7p
public static void sleep(int nSecond) HxR5&o
{ F~v0CBcAL
try{ F4=X(P_6
Thread.sleep(nSecond); Ne9VRM P
} c*owP
catch(Exception e) g#P]72TQ
{ |+h x2?Nv
e.printStackTrace (); k6 OO\=
} &LV'"2ng8
} G$)q% b;Lz
7IUJHc[R?
//日志 =8vwaJ
public static void log(String sMsg) Zq{gp1WC
{ ^Cp;#|g,
System.err.println(sMsg); `_&vvJPn@!
} Urw =a$
wI7.M Gt
yTc&C)Jba
public static void log(int sMsg) Z2;~{$&M+
{ FS7D
System.err.println(sMsg); B|syb!g
} Bz{"K
} U7LCd+Z5X
`MT.<5H
P{RGW.Ci@
/* pw))9~XU
**TestMethod.java u$qasII
*/ k-4z2qB
package NetFox; Yi-,Pb?
{DVMs|5;^
5/hgWG6.t
public class TestMethod { ga'G)d3oS
{#=o4~u%;H
.Z`xNp
public TestMethod() U4"&T,'lTL
{ ///xx/weblogic60b2_win.exe 0{!-h
try{ /`qQWB5b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Gu(Yoa}y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RSeav
SiteFileFetch fileFetch = new SiteFileFetch(bean); n1x3q/~
fileFetch.start(); Vf(..8
} AO-~dV
catch(Exception e){e.printStackTrace ();} 9qq6P!
0W 1bZPM
=BD|uIR
} =q[+e(,3
uC]c`Ue
eiA$) rzy
public static void main(String[] args) ?`:+SncI"b
{ M)v='O<H8
new TestMethod(); ,=pn}\R
} fHuWBC_YO
} un`4q-S7
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