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)); .;? Bni
} 1Bytu >2
for(int i=0;i<nEndPos.length-1;i++) A 6(`
{ x YS81
nEndPos = nStartPos[i+1]; ~A0]vcP
} {[y6qQm
nEndPos[nEndPos.length-1] = nFileLength; $WAwMS,
} IiYL2JS;t|
} mF7Ak&So^
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sx,$W3zI'G
//启动子线程 FYAEM!dyy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sn=6[RQ>P
for(int i=0;i<nStartPos.length;i++) 3smkY
{ \:vF FK4a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WogUILB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ot=>~(u0
nStartPos,nEndPos,i); .3 EZk86
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,KY;NbL-Jp
fileSplitterFetch.start(); k8gH#ENNK
} E|O&bUMh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), At7!Pas#@g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]N>ZOV,>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #:)'D?,
nEndPos = " + nFileLength); sI>w#1.m/&
// fileSplitterFetch[nPos.length-1].start(); 0seCQANd
]*0zir/
[|nK5(e9
//等待子线程结束 E7uIur=g!
//int count = 0; vhe Y F@
//是否结束while循环 TvU z^
boolean breakWhile = false; |x}TpM;ni
1XGg0SC
Cfi{%,em
while(!bStop) Jh"[ug
{ !3b& S4
write_nPos(); :.:^\Q0
Utility.sleep(500); oW^b,{~V
breakWhile = true; ZrN(Mp
&;PxDlY5
JE.$]){
for(int i=0;i<nStartPos.length;i++) $AK ^E6
{ H%_^Gy8f
if(!fileSplitterFetch.bDownOver) q"d9C)Md
{ vs@d)$N
breakWhile = false; ETDWG_H |
break; :V/".K-:J
} 6H#:rM
} Ycr3$n]e
if(breakWhile) VU3RFl
break; ~&?([}A
\@Wv{0a(
>S5J^c
//count++; pW]j.JM
//if(count>4) WjVBz
// siteStop(); JVAyiNIH>M
} +Mj6.X
;lMvxt:
@-@Coy 4Tt
System.err.println("文件下载结束！"); !6/UwPs
} {vu\qXmMv
catch(Exception e){e.printStackTrace ();} oO2DPcK
} ?9 huuJs7
AR|4^
Nd(,oXa~
//获得文件长度 Tm%5:/<8
public long getFileSize() `d <`>
{ Q{/z>-X\x
int nFileLength = -1; t=%zY~P
try{ \Ec<ch[)c
URL url = new URL(siteInfoBean.getSSiteURL()); sI,cX#h&Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wNa5qp 0
httpConnection.setRequestProperty("User-Agent","NetFox"); =!TUf/O-
E\iK_'#
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int responseCode=httpConnection.getResponseCode(); K^WDA])
if(responseCode>=400) %.bDK}
{ *HrEh;3^J
processErrorCode(responseCode); }*x1e_m}H
return -2; //-2 represent access is error BM :x`JY
} N*gJu
/k.0gYD
E'6>3n
String sHeader; \h ~_<)
#*(}%!rD*
!vz'zy)7
for(int i=1;;i++) hFV,FBsAO
{ 6,t6~Uo/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); & SXw=;B
//Utility.log(in.readLine()); rm-d),Zt
sHeader=httpConnection.getHeaderFieldKey(i); M=,pn+}y>
if(sHeader!=null) %&L13:
{ V.B@@ ;
if(sHeader.equals("Content-Length")) 6uE20O<z]
{ k_pv6YrE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); poz_=,c
break; <H-Nft>O
} kpgvAKyx
} QE]'Dc%
else Ts!'>_<Je
break; 4[lFurH
} !2t7s96
} ~,lt^@a
catch(IOException e){e.printStackTrace ();} ')jItje|
catch(Exception e){e.printStackTrace ();} y 4i3m(S
R ]Ev=V'U
:1+Aj (
Utility.log(nFileLength); @.;+WQE
{!Qu(%
^4sfVpD2!
return nFileLength; mSYjc)z
} M`Y^hDl6
%lCZ7z2o
7}iv+rQ
//保存下载信息（文件指针位置） 66val"^W
private void write_nPos() [Uup5+MCv
{ )+ <w>pc
try{ H(y`[B,}*
output = new DataOutputStream(new FileOutputStream(tmpFile)); \%7*@&
output.writeInt(nStartPos.length); /,G `V
for(int i=0;i<nStartPos.length;i++) TPp]UG
{ xpdpD
// output.writeLong(nPos); 1T|f<ChIF<
output.writeLong(fileSplitterFetch.nStartPos); eB0exPz%
output.writeLong(fileSplitterFetch.nEndPos); <8WFaP3,
} (3n "a'
output.close(); snaAn?I4
} "0eX/rY%
catch(IOException e){e.printStackTrace ();} oc1BOW z
catch(Exception e){e.printStackTrace ();} |~Dl<#58
} 'i+L
tpWGmjfo>
xQsxc
//读取保存的下载信息（文件指针位置） 3=enk0$
private void read_nPos() ;!<}oZp{
{ OnTe_JML
try{ 5dj" UxH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]\*^G@HA2
int nCount = input.readInt(); 3d}v?q78
nStartPos = new long[nCount]; NQ{(G8x9
nEndPos = new long[nCount]; F`g(vD>
for(int i=0;i<nStartPos.length;i++) H07\z1?.K
{ #eW T-m
nStartPos = input.readLong(); `n&:\Ib
nEndPos = input.readLong(); zQ,rw[C"W
} R4p Pt
input.close(); .UPh
} `7/(sX.
catch(IOException e){e.printStackTrace ();} KF(H >gs
catch(Exception e){e.printStackTrace ();} 4aO/^Hl
} =:rg1wo"c
-,8LL@_
8lusKww
private void processErrorCode(int nErrorCode) SAP/jD$5]>
{ N{%7OG
System.err.println("Error Code : " + nErrorCode); 8'PZA,CW
} 6n]+(=
BqNsW (+
B=0^Rysg
//停止文件下载 5/"$_7"{a
public void siteStop() [=K lDfU=
{ Qx)b4~F?
bStop = true; zud_BOq{f
for(int i=0;i<nStartPos.length;i++) vT?^#
fileSplitterFetch.splitterStop(); :[CV_ME.;
sF{~7IB
a7g;8t-&
} k%6CkCw
} <- \|>r Q
//负责部分文件的抓取 6?a`'&
**FileSplitterFetch.java A-!e$yz>
*/ aqON6|6K
package NetFox; zj7ta[<tr
}zGx0Q
Tz1^"tx9
import java.io.*; ?Bf>G]zx
import java.net.*; r `PJb5^\|
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0:V/z3?
public class FileSplitterFetch extends Thread { $cSUB
B%tF|KKj
$7q3[skH
String sURL; //File URL 4aHogheg
long nStartPos; //File Snippet Start Position nQc,^A)I
long nEndPos; //File Snippet End Position +4 k=Y
int nThreadID; //Thread's ID 4Fg2/O_3
boolean bDownOver = false; //Downing is over x*1wsA
boolean bStop = false; //Stop identical z$Jm1l
FileAccessI fileAccessI = null; //File Access interface P)vD?)Q
FCt<h/
JX&U?Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WFF?VBT'^
{ 3m>YR-n$
this.sURL = sURL; 7${<u0((!
this.nStartPos = nStart; 7DAP_C
this.nEndPos = nEnd; w5>[hQR\
nThreadID = id; .8YxEnXw)(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RBQ8+^
} h4]^~stI
iwF_'I$#N
'WW:'[Syn'
public void run() @} Ig*@
{ 0=>$J WF
while(nStartPos < nEndPos && !bStop) Qj^Uz+b
{ Wj.t4XG!
QXb2jWz
Z!g6uV+.5
try{ bB$f=W!m%
URL url = new URL(sURL); p]kEH\ sh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @_do<'a
httpConnection.setRequestProperty("User-Agent","NetFox"); }#^Cj;
String sProperty = "bytes="+nStartPos+"-"; 9"P+K.%
httpConnection.setRequestProperty("RANGE",sProperty); M+%Xq0`T
Utility.log(sProperty); <@Q27oEuA
d]0:r]e
w;,34qbf
InputStream input = httpConnection.getInputStream(); &'u|^d
//logResponseHead(httpConnection); it}h8:^<
b<tV>d"Fv
<D|&)/#
byte[] b = new byte[1024]; Kg6J:HD49
int nRead; 9VW/Af
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ek&~A0k_o
{ |.@!CqJ
nStartPos += fileAccessI.write(b,0,nRead); T1C_L?L
//if(nThreadID == 1) :Q`Of}#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pB:XNkxL
} E ASnh
T 6D+@i
boojq{cvYA
Utility.log("Thread " + nThreadID + " is over!"); BeUyt
bDownOver = true; ] hT\"5&6
//nPos = fileAccessI.write (b,0,nRead); }#m9Q[
} vaeQ}F
catch(Exception e){e.printStackTrace ();} h~#iGs
} m.+h@
} OH/9<T?
*J4!+GD
^os_j39N9
//打印回应的头信息 {dF@Vg_n
public void logResponseHead(HttpURLConnection con) L-Q8iFW'
{ Sqa9+' [
for(int i=1;;i++) ]zYIblpde
{ f7*Qa!!2p]
String header=con.getHeaderFieldKey(i); :u7BCV|yr
if(header!=null) =K:[26
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $z_yx `5
Utility.log(header+" : "+con.getHeaderField(header)); :aOR@])>o
else ^=x/:0
break; |Z>-<]p9g
} i"V.$|,
} )5@P|{FF
ykC3Z<pI.
E+Bc>xl@m
public void splitterStop() {z>!Fw
{ $6n J+
bStop = true; wNUT0+
} _WNbuk0
bpc1>?
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} J!om"h
x{;{fMN1
5$ik|e^:y
/* u4hn9**a1
**FileAccess.java Mst%]@TG
*//文件访问(定位，写) }-tJ.3Zw
package NetFox; >12jUm)
import java.io.*; _S) K+C|@
frcX'M}%
bkdXBCBx?
public class FileAccessI implements Serializable{ 5ih>x3S1/
+[ ?!@)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6c!F%xU}
RandomAccessFile oSavedFile; #H7 SLQr\
long nPos; JLm3qIC
Dspvc
|-ZML~2S=h
public FileAccessI() throws IOException vP,pK=5
{ Zd-qBOB2L
this("",0); 6 5zx<
} hr]+4!/
Vja 4WK*
Un8' P8C
public FileAccessI(String sName,long nPos) throws IOException (EcP'F*;;y
{ pT=^o
oSavedFile = new RandomAccessFile(sName,"rw"); NlF*/Rs
this.nPos = nPos; !BVCuuM>w
oSavedFile.seek(nPos); 'TYO-'aC
} -n7@r
lq.:/_m0
fDDpR=
public synchronized int write(byte[] b,int nStart,int nLen) <h#7;o
{ ovN3.0tAI
int n = -1; HsYzIQLL
try{ |"K%Tvxe
oSavedFile.write(b,nStart,nLen); Do(G;D`h+_
n = nLen; '|gsmO
} 7l7VT?<:
catch(IOException e) ; s(bd#Q
{ sq=EL+=j
e.printStackTrace (); b; of9hY
} f&$Bjq
vFL$wr
s 4rva G@a
return n; jUE:QOfRib
} ;R6f9tu2
m|fcWN[
AO`@&e]o
} Rng-o!
HIw)HYF2
3~fi#{
/* :JSxsA6k
**SiteInfoBean.java 3F"vK
*/ SOG(&)b
package NetFox; GI{EP&C
%!iqJ)*~
@"s<0T^H
public class SiteInfoBean { b$;oty9Y
UA'bE~i
-Y+pLvG*
private String sSiteURL; //Site's URL g<;pyvq|:
private String sFilePath; //Saved File's Path 0fstEExw
private String sFileName; //Saved File's Name lO\HchGzB
private int nSplitter; //Count of Splited Downloading File WCd:(8B
mKtMI!FR
,W+=N"`a'
public SiteInfoBean() H,c1&hb/w
{//nSplitter的缺省值为5 ]?_~QE`
//default value of nSplitter is 5 1VYH:uGuAU
this("","","",5); $MvKwQ/
} zq+2@"q
nN$.^!;&
}s?3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @ *Jbp
{ *[cCY!+Qy
sSiteURL= sURL; $|Ol?s
sFilePath = sPath; R/1e/t
sFileName = sName; ri-&3%%z<
this.nSplitter = nSpiltter; hfJ&o7Dt
9q0s
x]YzVJ=Y
} kj|Oj+&
v1i-O'
F ]X<q uuL
public String getSSiteURL() ;4-$C=&
{ 3KqRw (BK
return sSiteURL; !DA4q3-U>>
} q;R&valn
cL .z{
2Rys:$
public void setSSiteURL(String value) enxb pq#
{ gWjYS#D
sSiteURL = value; Vc(kw7
} _fgsHx>l7
B!<B7Q
|{|B70v3Co
public String getSFilePath() R7b-/ !L
{ Vxrj(knck,
return sFilePath; M&=SvM.f
} 7]So=%q
?v,c)
tMdSdJ8
public void setSFilePath(String value) V1P]pP
{ |63uoRr
sFilePath = value; ~9rNP{+
} D4"<suU|.
k2loGvBJ
F+VNrt-
public String getSFileName() DNDzK iMk
{ VQf^yq
return sFileName; Uth+4Aq
} $C=XSuPNK
c{`!$Z'k<
lNc0znY
public void setSFileName(String value) PC"=B[OlJ
{ 4D5Wse
sFileName = value; D$KP>G
} | J'k9W"
RpU i'
(Of`VT3ZOA
public int getNSplitter() $#%R_G]
{ l %zbx"%x
return nSplitter; iiuT:r
} x]Nx,tt
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|H8C4^1Rq
public void setNSplitter(int nCount) [V /f{y~{
{ )6"p@1\u
nSplitter = nCount; BGVnL}0
} }'{"P#e8"q
} X9c<g;
731RqUR
>8{{H"$;(
/* bCTN^
**Utility.java 3P75:v
*/ X:f5t`;
package NetFox; %d-WQwJ
(-1{W^(
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public class Utility { a{^2c!
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[[w-~hHH-
public Utility() Ymnh%wS
{ Qru&lAYc<
3XUVUd~
Xsn M}
} sJQ~:p0e
UZ<.R"aK
//线程睡眠 C_;nlG6
public static void sleep(int nSecond) VNz?e&>
{ _ZJQE>]nWu
try{ Nz"K`C>/
Thread.sleep(nSecond); %c$|.TkX
} `o9:6X?RA
catch(Exception e) @ZYJY
{ 9;n*u9<
e.printStackTrace (); Uv?^qe0=
} 1QhQ#`$<1
} K)1Lg?j
npytb*[|c
//日志 c9@3=6S/
public static void log(String sMsg) ?&qQOM~b-\
{ 9%R"(X)
System.err.println(sMsg); nT~XctwF
} ?|NsaW
A3HNMz
j,%i.[8S
public static void log(int sMsg) [SKDsJRPP
{ O\oRM2^u}
System.err.println(sMsg); dA2@PKK
} Gys-Im6>~@
} xz}CqPJ#
;X+.Ag
V\n!?1{kdF
/* uARkf'
**TestMethod.java N*PJ m6-
*/ d@8:f
package NetFox; vN]_/T+
R:'&>.AUw
,\\=f#c=
public class TestMethod { <)_#6)z:
%PPy0RZ^
xU{0rM"
public TestMethod() dB&<P[$+8
{ ///xx/weblogic60b2_win.exe FKe/xz
try{ ,T^A?t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DqI"B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "9X(.v0ze
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jv%)UR.]
fileFetch.start(); qv2J0'd'.
} C>-}BeY!
catch(Exception e){e.printStackTrace ();} S,,Wb&A$
iB~dO @
^%6f%]_
} QYj 4D
sVnq|[ /
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public static void main(String[] args) !K=$Q Uq
{ pvWj)4e
new TestMethod(); ;Hp78!#,
} 9N2.:<so
} N!tNRMTi
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