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)); 4?vTuZ/ M
} hG8!aJo
for(int i=0;i<nEndPos.length-1;i++) u\uYq
{ +)cjW"9
nEndPos = nStartPos[i+1]; L6jD4ec8
} "T?hIX/p_
nEndPos[nEndPos.length-1] = nFileLength; c-ud $0)c
} *w/})Y3^
} /^XGIQ/W
W :qQ
1(;_1@P
//启动子线程 Ck;>9>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O:hCUr
for(int i=0;i<nStartPos.length;i++) RqenPMk
{ /3>5ex>PN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]'%Z&1 w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iFi6,V*PRt
nStartPos,nEndPos,i); 2X@|H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q^_*&},V
fileSplitterFetch.start(); QUSyVp{$
} lCznH?[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ujt0?DM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }CoR$K
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .dM|J'`g
nEndPos = " + nFileLength); ._$tNGI4
// fileSplitterFetch[nPos.length-1].start(); W ^MF3
='p&T|&
UmC_C[/n?
//等待子线程结束 ,{tK{XpS
//int count = 0; `RriVYc<
//是否结束while循环 zt23on2
boolean breakWhile = false; <691pkX
6n
R54wNm@
while(!bStop) Q9!T@
{ , (Bo .(]
write_nPos(); S{sJX5R;
Utility.sleep(500); -#e3aXe
breakWhile = true; |d@%Vb_
#"6O3.P
c[h{C!d1
for(int i=0;i<nStartPos.length;i++) DviRD[+q"
{ ;#goC N.
if(!fileSplitterFetch.bDownOver) 3a_=e B
{ Rb8wq.LqD
breakWhile = false; 8pEiU/V
break; 6H)T=Z|
} \*(A1Vk
} j\o<r0I
if(breakWhile) "%~Jb dx
break; Y<"BhE
;B,6v P#
n*Q~<`T
//count++; Q=+*OQV29
//if(count>4) l[G&=/R@H
// siteStop(); h:J0d~u
} vs`"BQYf
t\/i9CBn
f2abee
System.err.println("文件下载结束！"); {&bjjM
} V2&O]bR
catch(Exception e){e.printStackTrace ();} zK5/0zMZ
} ZYi."^l
ev$\Ns^g$3
XlPi)3m4/S
//获得文件长度 _(R1En1
public long getFileSize() p#yq'kY
{ L93PDp4v
int nFileLength = -1; "Q>gQKgL
try{ LxcC5/@\~(
URL url = new URL(siteInfoBean.getSSiteURL()); VD,p<u{r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PGE|){ <
httpConnection.setRequestProperty("User-Agent","NetFox"); #2XX[d%
_~=qByD
!(-lY(x
int responseCode=httpConnection.getResponseCode(); gYtv`O
if(responseCode>=400) *j9hjq0j
{ Hw(_l,Xf
processErrorCode(responseCode); "k0bj>
return -2; //-2 represent access is error =FB[<%
} l[_y|W5
a&?SRC'x
vzr?#FG
String sHeader; 5vfzSJ
!sJ*0
;g:!WXd
for(int i=1;;i++) Q"@x,8xW
{ _yu d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =tS1|_
//Utility.log(in.readLine()); 0pC}+ +
sHeader=httpConnection.getHeaderFieldKey(i); 9}=]oX!+V
if(sHeader!=null) ;F/yS2p
{ 323zR*\m
if(sHeader.equals("Content-Length")) cg]\R1Gm
{ d&@>P&AT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %YH+=b:uW
break; E6=JL$"
} sv g`s,g
} 3>+9Rru
else TN+iv8sT
break; Q7~9~
} r}9a31i
} /CE]7m,7~K
catch(IOException e){e.printStackTrace ();} 3Y L
catch(Exception e){e.printStackTrace ();} Hju7gP=y}
lU}y%J@
U@6bH@v5
Utility.log(nFileLength); xYgG
_`H2CXGg
XVlZ:kz
return nFileLength; h0=Q.Yz6
} (F<VcB
aT]G&bR?
n{b(~eL?
//保存下载信息（文件指针位置） ;j#(%U]Vp
private void write_nPos() _0v+g1x
{ w[WyT`6h!
try{ :cvZk|b%
output = new DataOutputStream(new FileOutputStream(tmpFile)); w6-A-M6hD
output.writeInt(nStartPos.length); z)Yk&;XC
for(int i=0;i<nStartPos.length;i++) Ny\c>$z
{ {x-iBg9#l2
// output.writeLong(nPos); D)]U+Qk
output.writeLong(fileSplitterFetch.nStartPos); a/nKKhXaM
output.writeLong(fileSplitterFetch.nEndPos); TSl:a &
} L,m'/}$
output.close(); :3uCW1
} hJkSk;^
catch(IOException e){e.printStackTrace ();} J0 [^hH
catch(Exception e){e.printStackTrace ();} `YK2hr
} j/oM^IY
=u*\P!$
.[@TC@W
//读取保存的下载信息（文件指针位置） }k`-n32)|
private void read_nPos() *tWZ.I<<
{ Y`O"+Jr
try{ fku\O<1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HP$GI
int nCount = input.readInt(); FuWMVT`Y
nStartPos = new long[nCount]; yU e7o4Zm
nEndPos = new long[nCount]; Rr9K1io$)
for(int i=0;i<nStartPos.length;i++) (.CEEWj%{
{ 86bRfW'
nStartPos = input.readLong(); )@IDmz>
nEndPos = input.readLong(); @y|ZXPC#
} S,=#b 4\#%
input.close(); pd3=^Zi
} MR) *Xh
catch(IOException e){e.printStackTrace ();} ?$ft3p}
catch(Exception e){e.printStackTrace ();} \~LwlOo%R
} ??'>kQ4
(9"w{pnlLc
J'Z!`R|
private void processErrorCode(int nErrorCode) MHuQGc"e+4
{ 'aWrjfDy:
System.err.println("Error Code : " + nErrorCode); 9*thqs3J#d
} g!#M0
4*)a3jI?
^B>BA
//停止文件下载 4TPAD)C
public void siteStop() d){o#@
{ YqJ `eLu
bStop = true; Gr&)5hm$
for(int i=0;i<nStartPos.length;i++) D?)^{)49
fileSplitterFetch.splitterStop(); /K@_O\+;Q
q&:UP
y1oQ4|KSI
} ^`HP&V
} 2"'<Yk9
//负责部分文件的抓取 E1=WH-iA0
**FileSplitterFetch.java xw>\6VNt
*/ oHW:s96e
package NetFox; 2j*+^&M/
~]d3 f
||}k99y +
import java.io.*; 3pV^Oe^9
import java.net.*; o_(@v2G`
O/?Lk*r
$ykujyngS4
public class FileSplitterFetch extends Thread { &=KNKE`
Hv>16W$_
*-zOQ=Y
String sURL; //File URL &|d6
long nStartPos; //File Snippet Start Position ' )0eB:
long nEndPos; //File Snippet End Position 6*{sZMG
int nThreadID; //Thread's ID 3eg)O34
boolean bDownOver = false; //Downing is over Wubvvm8U
boolean bStop = false; //Stop identical "-WEUz
FileAccessI fileAccessI = null; //File Access interface hHu?%f*
; qQ* p
mmJ$+$JEk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cLZaQsS%
{ =vpXYj
this.sURL = sURL; d'x'hp%
this.nStartPos = nStart; wa)E.(x
this.nEndPos = nEnd; [!<W{ ($5
nThreadID = id; +s`HTf
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t&oNC6
} w@jC#E\
LE'8R~4.<
gf&\)"
public void run() ik;S!S\v
{ ,sOdc!![
while(nStartPos < nEndPos && !bStop) ;b-d2R
{ 0-=PP@W
6AA"JX
++d%D9*V<
try{ .$rt>u,8<
URL url = new URL(sURL); qgk-[zW#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %VSjMZ
httpConnection.setRequestProperty("User-Agent","NetFox"); q[wVC h
String sProperty = "bytes="+nStartPos+"-"; ri]"a?Rm
httpConnection.setRequestProperty("RANGE",sProperty); ac2G;}B|
Utility.log(sProperty); Rg3cqe#O/
mF6 U{=
5, j&-{0W
InputStream input = httpConnection.getInputStream(); *!wBn
//logResponseHead(httpConnection); ;7HL/-
C<T)'^7z
w.:fl4V
byte[] b = new byte[1024]; =Qf.
int nRead; RyN}Gz/YN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FUD M]:XQ
{ vhEXtjL
nStartPos += fileAccessI.write(b,0,nRead); d4r@Gx%BE
//if(nThreadID == 1) nXg:lCI-uu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @ uF$m/g
} x+%(z8wD
l)d(N7HME
4(hHp6}b
Utility.log("Thread " + nThreadID + " is over!"); Wifr%&t{J
bDownOver = true; 2H]~X9,z2
//nPos = fileAccessI.write (b,0,nRead); HTa]T'
} fl4z'8P"(
catch(Exception e){e.printStackTrace ();} ij|+MX
} ; *@lH%u
} NCKhrDd&
xc&&UKd
^p2_p9
//打印回应的头信息 1pDL()t
public void logResponseHead(HttpURLConnection con) oA;> z
{ |_H{B+.
for(int i=1;;i++) O^_$cq
{ fPj*qi
String header=con.getHeaderFieldKey(i); 9?6]Zag
if(header!=null) (9A`[TRwi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jW!x!8=
Utility.log(header+" : "+con.getHeaderField(header)); 5RUhrE
else u~-,kF@
break; c[6=&
} Rr!oT?6J?
} ^]_5oFRIj
DEFh&n
/+p]VHP\
public void splitterStop() m|%L[h1
{ ,Qw\w,
bStop = true; SBbPO5^](
} RPh8n4&("
UEb'b,O_9
|nu)=Ag
} `;R [*7
IuW5LS
,RYahu
/* {<k}U;uiO
**FileAccess.java w<o#/J9
*//文件访问(定位，写) &UV=<Az{
package NetFox; .>;}GsN&
import java.io.*; \U\k$ (
7Gs0DwV
~Bi{k'A9
public class FileAccessI implements Serializable{ MF}}o0P
% njcWVP;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sd\+f6x
RandomAccessFile oSavedFile; b- FJMY
long nPos; wvuh
B+pJWl8u
Kd%>:E*
public FileAccessI() throws IOException 4or8fG
{ .%3qzOrN
this("",0); efnj5|JSV
} G#(+p|n
J nzI- y
1oVjx_I5y
public FileAccessI(String sName,long nPos) throws IOException L74Sx0nk=
{ 28jm*Cl8
oSavedFile = new RandomAccessFile(sName,"rw"); GO|EeM!iB
this.nPos = nPos; \.AI;^)X@]
oSavedFile.seek(nPos); L[LgQ7esQ
} xdV $dDCT
!arTR.b\
6z2_b wo
public synchronized int write(byte[] b,int nStart,int nLen) eCI0o5U
{ >RL|W}tI4
int n = -1; /U1 jCLR'
try{ Z9+xB"q2
oSavedFile.write(b,nStart,nLen); h=`1sfz
n = nLen; UZqQ|3
} : ~R:[T2P
catch(IOException e) ;^cc-bLvF
{ =w/S{yC
e.printStackTrace (); %x5zs ]4^
} ,VTX7vaH
j}devpO
VJ'bS9/T
return n; N:yyDeGyW
} 9tZ+?O5
5%Xny8 ]|D
(qky&}H
} h4 X>
H>/LC* 8-
MY$-D+#/`
/* U(t_uc5q
**SiteInfoBean.java iI.d8}A
*/ G"'[dL)N>
package NetFox; HsQ\xQ"k!
U}]uPvu
q&y9(ZvI
public class SiteInfoBean { 0u7\*Iy
:: 2pDtMS
)b_ GKA `
private String sSiteURL; //Site's URL ::Nhs/B/
private String sFilePath; //Saved File's Path 7Hm/g
private String sFileName; //Saved File's Name ^^m3 11=
private int nSplitter; //Count of Splited Downloading File k"V@9q;*
#VA8a=t
*G,'V,?
public SiteInfoBean() k.dQ;v}
{//nSplitter的缺省值为5 Ue8k9%qV
//default value of nSplitter is 5 ,aLdW,<6
this("","","",5); 0k7kmDW
} ~=pAy>oV
i H^Gv*
HR> X@g<c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [61T$.
{ WV8?zB1
sSiteURL= sURL; lW8!_h"G`n
sFilePath = sPath; bR*/d-v^
sFileName = sName; jRv j:H9
this.nSplitter = nSpiltter; nYv`{0S+m
UJX=lh.o
:.k)!
} oF(<}0Z
1D pRm(
t'F_1P^*/
public String getSSiteURL() )&$Zt(
{ " ~X;u8m
return sSiteURL; vMQvq9T}
} >10pk
.vbUv3NI
p7YfOUo k
public void setSSiteURL(String value) PilV5Gg
{ %N, P? ,U
sSiteURL = value; 7z?rx
} I}@m6D|\
)7j CEA03
M-B-
public String getSFilePath() jP-=x(
{ iQI$Y]Y7
return sFilePath; q|[P[7z
} W97%12J3
J:c]z9&!
]q2g[D o5
public void setSFilePath(String value) Yom,{;Bv
{ MDo4{7
sFilePath = value; hSvA dT]m
} O+o4E?}
bLHj<AX#>|
qU1^ K
public String getSFileName() &Vtgh3I
{ oo:(GfO}
return sFileName; d/Z258
} ?xTh}Sky
_Q:739&
qhPvU( ,
public void setSFileName(String value) V@(7K0
{ ARZ5r48)
sFileName = value; $|2@of.
} "?lm`3W"
@"`{gdB$
2`o}neF{
public int getNSplitter() J01Y%W
{ #e!4njdM
return nSplitter; &d`z|Gx9
} wK7wu.
QqC4g]
Eoj 2l&\
public void setNSplitter(int nCount) 'Gw;@[
{ CulU?-[i
nSplitter = nCount; \rw/d5.
} ma\UJz
} `xhiG9mz~
=.]>,N`C
ww]^H$In
/* G2nL#l~@)
**Utility.java CFW\
*/ b83__i
package NetFox; w :w
+!I7(gL
$hkMJ),T~
public class Utility { ~)zoIM\
A-GRuC
NdS6j'%B@7
public Utility() T/_JXK>W
{ )m-l&UK
>t/P^fr_F
DiB~Ovh|
} Rv)!p~V8
3q>6gaTv
//线程睡眠 5K;vdwSB
public static void sleep(int nSecond) L29,Y=n@
{ Vs1j9P|G
try{ [\M=w7
Thread.sleep(nSecond); y1JxAj
} $>3/6(bW
catch(Exception e) j;tT SNF
{ UH<nc;.B
e.printStackTrace (); Q}J'S5%
} %0PdN@I
} &AMW?vO
ZwLD7j*)
//日志 0.}Um
public static void log(String sMsg) Ufz& 2
{ LiyEF&_u
System.err.println(sMsg); hSZ0 }/
} S^GB\uJ
0x}8}
!9!kb
public static void log(int sMsg) -}lcMZY
{ +$#YW5wy
System.err.println(sMsg); '8NKrI
} 1@nGD<,.
} %`%xD>![
_jw A_
kF9T 9
/* uv++Kj!
**TestMethod.java 3dnL\AqC
*/ D?rQQxb
package NetFox; ,.`";='o
WV5gH*uUa
ex8mA6g
public class TestMethod { P5ii3a?R
X6mY#T'fQ
k--.g(T
public TestMethod() 0px@3/
{ ///xx/weblogic60b2_win.exe =KwG;25hX
try{ +]Oq{v:e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5=g{%X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rN)T xH&*p
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4A%O`&eZ
fileFetch.start(); ,jyNV<dI
} YMG{xGPtM
catch(Exception e){e.printStackTrace ();} 22L#\qVkl
XF1x*zc
0X\,!FL
} &oevgG
8jxgSB",
dOq*W<%
public static void main(String[] args) w\pD'1e
{ QQKvy0?1
new TestMethod(); Cw]Q)rX{
} E9 QA<w
} \%9,<-~[
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