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)); kz"uTJK
} qos7u91z
for(int i=0;i<nEndPos.length-1;i++) afEa@et'
{ Z'JS@dV
nEndPos = nStartPos[i+1]; =?fz-HB
} 9t"Rw ns
nEndPos[nEndPos.length-1] = nFileLength; IU%|K~_n
} W(s4R,j
} iq(PC3e`V
|"3<\$[
|p11Jt[
//启动子线程 }{o!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e#(Ck{e
for(int i=0;i<nStartPos.length;i++) o\IMYT
{ %qP[+N&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c3A\~tHW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m~ tvuz I
nStartPos,nEndPos,i); >H2`4]4]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n|SV)92o1
fileSplitterFetch.start(); ;;Q^/rkC
} 1j<(?MT-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6o3 bq|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O !L`0 =%c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ':'g!b`/
nEndPos = " + nFileLength); 'X`Z1L/
// fileSplitterFetch[nPos.length-1].start(); *z=_sD?1
[I $+wWW_
?Ec9rM\ze
//等待子线程结束 RgE`Hr
//int count = 0; woYD &Oml
//是否结束while循环 l\HdB"nT
boolean breakWhile = false; R?2sbK4Cz
@fL ^I&++
yVd^A2
while(!bStop) [m t.2.
{ .J"N}
write_nPos(); 1^p/#jt
Utility.sleep(500); E h%61/
breakWhile = true; d"$8-_K
.1x04Np!
Kz4S6N c
for(int i=0;i<nStartPos.length;i++) pMc6p0
{ N+-Tp&:wY
if(!fileSplitterFetch.bDownOver) DHidI\*gT
{ LSo!_tY
breakWhile = false; X'9.fKp
break; z`y9<+
} +jN}d=N-
} x%P|T3Qy5
if(breakWhile) ?0tg}0|
break; bdUPo+
s:`i~hjq
R#(0C(FI^
//count++; G4&s_M$
//if(count>4) 3P>gDQP
// siteStop(); r );R/)&
} J( }2Ua_
7*'/E#M
;`9f<d#\
System.err.println("文件下载结束！"); \/-c)
} <G"cgN#]
catch(Exception e){e.printStackTrace ();} ]n ?x tI
} A=CeeC]}
#F*|@
:fRXLe1=
//获得文件长度 _Fb}zPU!
public long getFileSize() b^Hrzn
{ ,CO2d)}
int nFileLength = -1; B( [x8A]
try{ vL/ 3(Bo7
URL url = new URL(siteInfoBean.getSSiteURL()); ^}3^|jF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a(Y'C`x
httpConnection.setRequestProperty("User-Agent","NetFox"); -F[8ZiZ
h@)U,&
\}-4(Xdaq
int responseCode=httpConnection.getResponseCode(); wak26W>I3
if(responseCode>=400) \?bV\/GBR
{ St=nf\P&F
processErrorCode(responseCode); R^Rc!G}
return -2; //-2 represent access is error >hKsj{=R7
} y48]|%73
fV:15!S[
V>$( N/1
String sHeader; <Ij!x`MS+
AXfU$~
^5 >e
for(int i=1;;i++) D6SUzI1+H
{ 2 a<\4w'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z\$HgG
//Utility.log(in.readLine()); |9@,ri\'Rg
sHeader=httpConnection.getHeaderFieldKey(i); (1/Sf&2i
if(sHeader!=null) 8K8u|]i
{ # @\3{;{R
if(sHeader.equals("Content-Length")) ` Xc7b
{ ;5a$OM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9O[IR)O~
break; !3Dq)ebBz
} {sTf4S\S
} lR(9;3
else e8a^"Z`a
break; Q G)s
} 1-RY5R}VR
} F?L]Dff
catch(IOException e){e.printStackTrace ();} u09Tlqh0 3
catch(Exception e){e.printStackTrace ();} _h%Jf{nu
7T[~~V^x
!_glZ*tL
Utility.log(nFileLength); I2}W/}
[V}vd@*k
o<g?*"TRh
return nFileLength; OM'iJB6=
} iUKjCq02
ZlV
FT).$h~+4
//保存下载信息（文件指针位置） 1N5 E
private void write_nPos() +Z#=z,.^
{ SH*'<
try{ o.s'0xP]
output = new DataOutputStream(new FileOutputStream(tmpFile)); $-_" SWG.
output.writeInt(nStartPos.length); >}k*!J|
for(int i=0;i<nStartPos.length;i++) cIug~ x>
{ {uDW<u_!
// output.writeLong(nPos); =D zrM%
output.writeLong(fileSplitterFetch.nStartPos); a%go[_w
output.writeLong(fileSplitterFetch.nEndPos); 2"0VXtv6
} 4+olyBht
output.close(); L3]J8oEmU
} !~^2Mu(X
catch(IOException e){e.printStackTrace ();} tqZ91QpW
catch(Exception e){e.printStackTrace ();} MmJMx
} hV3]1E21"
3s\UU2yr
vc#o(?g
//读取保存的下载信息（文件指针位置） %<i sdvF
private void read_nPos() u5CSx'h]
{ hB?#b`i^
try{ L5hF-Ek! 3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QPy h.9:N
int nCount = input.readInt(); [bLKjD
nStartPos = new long[nCount]; >^8O:.
nEndPos = new long[nCount]; 4vg,g(qi<
for(int i=0;i<nStartPos.length;i++) 8~y!X0Ov!
{ r*HSi.'21
nStartPos = input.readLong(); LcKc#)'EE
nEndPos = input.readLong(); ff9m_P
} 6O4*OR<&
input.close(); /cS8@)e4
} AFt- V
catch(IOException e){e.printStackTrace ();} 6 `6I<OJ\
catch(Exception e){e.printStackTrace ();} tbQY&TO1
} +;,{`*W+N
&zn|),
V7$ m.P#uM
private void processErrorCode(int nErrorCode) rEr=Mi2
{ %/eG{oh-
System.err.println("Error Code : " + nErrorCode); jLFaf#G]
} Uahh|>s
lU 9o"2
,|f=2t+5X
//停止文件下载 ~HY)$Yp;
public void siteStop() (U\o0LI
{ df{?E):
bStop = true; O!PGZuF
for(int i=0;i<nStartPos.length;i++) lB}?ey
fileSplitterFetch.splitterStop(); 5?3v;B6
f y|JE9Io_
CfOyHhhKX
} y^r'4zN'
} \]Y<d
//负责部分文件的抓取 azZ|T{S
**FileSplitterFetch.java yCz"~c
*/ =u0=)\0@r
package NetFox; `&I6=,YLp
,WdSJ BK'a
=Vh]{y~$
import java.io.*; JKKp5~_~
import java.net.*; *Y1s4FXu2
M_O$]^I3w
^uo,LTq+
public class FileSplitterFetch extends Thread { xK8m\=#
6cg,L:j#
hzbvR~rn
String sURL; //File URL zt2#K
long nStartPos; //File Snippet Start Position A@M2(?w4
long nEndPos; //File Snippet End Position WLWfe-
int nThreadID; //Thread's ID ^PdD-tY<
boolean bDownOver = false; //Downing is over i~GW
boolean bStop = false; //Stop identical Sw$&E
FileAccessI fileAccessI = null; //File Access interface (9bU\4F\
.KYs5Qu
kW+>"3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |yNyk7~
{ ;8VZsh
this.sURL = sURL; };2Lrz9<
this.nStartPos = nStart; !d0$cF):
this.nEndPos = nEnd; y2k's
nThreadID = id; Pf8_6z_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zt((TD2
} 'bv(T2d~~
*{JD=ua
:wzbD,/M
public void run() Yy!G?>hC
{ 7ey|~u2
while(nStartPos < nEndPos && !bStop) .K940& Ui
{ Jbima>
&xj40IZ
AB!({EIi
try{ <qMX,h2
URL url = new URL(sURL); {3Gj rE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YC{7;=Pf
httpConnection.setRequestProperty("User-Agent","NetFox"); rI)&.5^
String sProperty = "bytes="+nStartPos+"-"; 9(&$Gwi
httpConnection.setRequestProperty("RANGE",sProperty); 4P2p|Gc3
Utility.log(sProperty); R]kH$0`
HDo=WqG
N}|1oQkjf
InputStream input = httpConnection.getInputStream(); \ }-v
//logResponseHead(httpConnection); ^[HX#JJ~
8Z@O%\1x6
Y\H4.$V
byte[] b = new byte[1024]; Y5>'(A>
int nRead; ;?o"{mbb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ']Km%uwL
{ y9:o];/
nStartPos += fileAccessI.write(b,0,nRead); /Wjf"dG}
//if(nThreadID == 1) '?|.#D#-c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?$7$# DX
} Tq6@ 1j6p
yErvgf
.|ZnU]~T
Utility.log("Thread " + nThreadID + " is over!"); lVb;,C%K
bDownOver = true; $L"-JNS
//nPos = fileAccessI.write (b,0,nRead); Zfr?(y+3
} X<"#=u(
catch(Exception e){e.printStackTrace ();} (7aE!r\Ab
} %ye4FwkRy
} =1kjKE !
!P)7t`X
64!V8&Ay
//打印回应的头信息 hWu#}iN
public void logResponseHead(HttpURLConnection con) {' |yb
{ rNHV
for(int i=1;;i++) =7("xz%
{ w*N9p8hb]
String header=con.getHeaderFieldKey(i); jr5x!@rb
if(header!=null) "V_PWEi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y)4D$9:
Utility.log(header+" : "+con.getHeaderField(header)); 785Y*.p
else t#g6rh&
break; QO~TuC
} >^Z!
} 80M4~'3
)%OV|\5#
M*c`@\
public void splitterStop() aKCXV[PO
{ Ec]cCLB
bStop = true; 7,"1%^tU
} eVWnD,'
'W j Q
.~ W^P>t
} Icf@uQ6
ffyKAZ{]po
"|"bo5M:
/* (5N&bh`E
**FileAccess.java Im_`q\i
*//文件访问(定位，写) p.1|bXY`
package NetFox; /m*vY`
import java.io.*; (sn|`k3I
oZ~M`yOz.
7b T5-=.
public class FileAccessI implements Serializable{ T[eTT]Z{Ia
9W7H",wR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !NYc!gYD
RandomAccessFile oSavedFile; 6q8qq/h)
long nPos; W~QZ(:IK
fr\UX}o
M|`%4vk>
public FileAccessI() throws IOException ^fb4g+Au
{ \Jv6Igu
this("",0); y#Ch /Jg?|
} I)O-i_}L&K
$0K9OF9$
}EOn=*
public FileAccessI(String sName,long nPos) throws IOException GYv2^IB:
{ @v2kAOw[
oSavedFile = new RandomAccessFile(sName,"rw"); Qo{^jDe,c*
this.nPos = nPos; +]|J
oSavedFile.seek(nPos); mnXaf)"
} 12E@9s$Z
'&T4ryq3"
F{f "xM
public synchronized int write(byte[] b,int nStart,int nLen) )CXJRo`j0
{ BbiBtU
int n = -1; S3j/(BG
try{ m&|?mTo>m
oSavedFile.write(b,nStart,nLen); FAU^(]-5m
n = nLen; 1p9f& w
} 9}2I'7]
catch(IOException e) .Fh5:WN
{ D@4hQC\
e.printStackTrace (); FQ(=Fnqn
} OjeM#s#N!
qdj,Qz9ly
'n.eCdj
return n; ^X0<ZI
} +\.gdL)
HPwmi[
`t ZvIy*
} GXRK+RHuBi
U#,2et6
]rHdG^0uss
/* d:=5y)
**SiteInfoBean.java vD}y%}
*/ UTmX"Li
package NetFox; &Cdk%@Tj]B
Ge[N5N>
](-:l6
public class SiteInfoBean { A*~zdZ p
`Nu3s<O7CF
+<AX 0(
private String sSiteURL; //Site's URL OYNs1yB
private String sFilePath; //Saved File's Path .#J'+LxFr
private String sFileName; //Saved File's Name (?YTQ8QR
private int nSplitter; //Count of Splited Downloading File hMeE@Q0
0sk*A0HX-
Ck(D: % ~s
public SiteInfoBean() kUn55 l
{//nSplitter的缺省值为5 "i4@'`r
//default value of nSplitter is 5 [ZOo%"M_Y
this("","","",5); I`E9]b(w
} SS@#$t:
m[Px|A5{
)5)S8~Oc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SG;]Vr
{ ;&^S-+
sSiteURL= sURL; LYkW2h`JQ
sFilePath = sPath; do7 [Nj
sFileName = sName; 6 }qNH29
this.nSplitter = nSpiltter; E,u@,= j
Yep(,J~'
b 9F=}.4
} xv9SQ,n<
*ukugg.
X@5!I+u\L
public String getSSiteURL() FSIV\ u
{ C8DZ:3E$c
return sSiteURL; $2 ~RZpS
} rH$0h2
\zR{D}aS
S3`zB?7,
public void setSSiteURL(String value) o-_0
{ ?o"wyF A*
sSiteURL = value; g(>;Z@Y
} a(NN%'fDD
3 =KfNz_
4[9~g=y>
public String getSFilePath() Txj%o5G
{ |k{?\(h;
return sFilePath; A+69_?B TH
} `BmAu[(e&
b-@6w(j
2N9 BI-a
public void setSFilePath(String value) LwZBM#_g
{ %XMrSlSOp
sFilePath = value; W> s@fN9
} [kMXr'TyPX
nMNAn}~*M
WhMr'l/e
public String getSFileName() /RT3r
{ 8G?'F${`
return sFileName; J@=1zL
} #%il+3J
&G@(f=
tV9BVsN
public void setSFileName(String value) 3o%JJIn&
{ $M@SZknm
sFileName = value; tYC`?HT
} FZ6.<wN
OziG|o@I
U#gHc:$
public int getNSplitter() A=o p R
{ f\!*%xS;
return nSplitter; 7v}4 Pl,$4
} .taJCE
&n|#jo(gS
(d |
public void setNSplitter(int nCount) Ro*$7j0!Hf
{ `o8b\p\zn
nSplitter = nCount; X4>c(1e
} 1M7=*w,
} i DO`N!
4xuL{z;\
X's-i!
/* B!K{y>|.
**Utility.java I1=YSi;A
*/ y%Ui)UMnw]
package NetFox; K2$mz
2mP| hp?
wh l)^D
public class Utility { ;TD<\1HJT=
W1$B6+}Z0V
ez%RWck
public Utility() (k"|k
{ ',n;ag`c
_|D8~\y
9aD6mp
} 6C9KT;6
lb2mWsg"
//线程睡眠 ]^Z7w`=%5
public static void sleep(int nSecond) d i`}Y&
{ l]Jk }.
try{ ?|Fu^eR%X
Thread.sleep(nSecond); R!lNm,i
} P.$U6cq
catch(Exception e) q]=.Aik
{ BoG/Hd.S
e.printStackTrace (); Na=9ju
} wxB?}
} 8s-RNA>7^
?^mgK9^v@
//日志 z11;r]VI
public static void log(String sMsg) &<R8'
{ .+]e9mV
System.err.println(sMsg); ,WR$xi.j
} `sQ\j Nu
1GN>,Lb:o
E D*=8s2
public static void log(int sMsg) 18z{d9'F
{ 90|p]I%
System.err.println(sMsg); L7_(KCh
} iaQ[}'6!$
} K20n355uE
HAEgR
/p~"?9b[ i
/* jy(,^B,]
**TestMethod.java J5)e 7
*/ Yd~K\tX:n
package NetFox; eJ+;!0
%P0dY:L~
OYzt>hdH
public class TestMethod { w(8q qU+\
!;{@O`j?b
s0H_Y'
public TestMethod() *_`T*$
{ ///xx/weblogic60b2_win.exe h?j;*|o-
try{ g9}u6q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qF`;xa%,}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @ \J RxJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); \=Af AO@
fileFetch.start(); q~p,A>K
} tPPnW
catch(Exception e){e.printStackTrace ();} Iwi>yx8
hE\,4c1
UBOCd[
} KSIH1E
IJ!]1fXy+
1iS9f~
public static void main(String[] args) b<_*~af
{ H.uflO
new TestMethod(); P{)H7B>
} ?u"(^93f
} J9)wt ?%j
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