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)); ub1~+T'O
} 3 %r*~#nz
for(int i=0;i<nEndPos.length-1;i++) 45Zh8k
{ :.BjJ2[S
nEndPos = nStartPos[i+1]; pE+:tMH;
} e{4e<hd
nEndPos[nEndPos.length-1] = nFileLength; d6m&nj
} 1W0[|Hf2v*
} )B-[Q#*A-
i*4v!(E
e50xcf1u
//启动子线程 \%]lsml
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *\iXU//^)
for(int i=0;i<nStartPos.length;i++) 6v}q @z
{ 41.xi9V2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X?u=R)uG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9P#kV@%(0c
nStartPos,nEndPos,i); m4~~q[t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R;U4a2~
fileSplitterFetch.start(); 8In~qf
} m,6u+Z,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .A/xH x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^xgPL'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BlT)hG(M>
nEndPos = " + nFileLength); H8@z/
// fileSplitterFetch[nPos.length-1].start(); X$t!g`
\ ux{J
|Q%nnN
//等待子线程结束 [z_ztK1
//int count = 0; (bNoe(<qU
//是否结束while循环 8OS^3JS3"
boolean breakWhile = false; _\@zq*E
!xg10N}I
w!d(NA<|0]
while(!bStop) "~Kph0-
{ >wYmx4W>
write_nPos(); g38MF
Utility.sleep(500); QR-pji y
breakWhile = true; Lcy6G%A
Sy*p6DP
t!FC)iY
for(int i=0;i<nStartPos.length;i++) .UN?Ak*R
{ ^x(s!4d]
if(!fileSplitterFetch.bDownOver) %\'G2
{ l]
breakWhile = false; L&|^y8
break; [oXr6M:
} @L607[!?
} 8{&.[SC7
if(breakWhile) r M}o)
break; |w>b0aY
,a2=OV
@,G\`;Ma
//count++; LH@Kn?R6
//if(count>4) xA*6Z)Y
// siteStop(); cnY}^_
} Cz&t*i/
]R09-s 0$7
3:OqD~,zy
System.err.println("文件下载结束！"); ET*:iioP
} u<Ch]m+
catch(Exception e){e.printStackTrace ();} &I{5f-o*
} "-IF_Hid
7#N= GN
qsQTJlq)
//获得文件长度 ][8`}ki 1
public long getFileSize() VhnIr#L+
{ qckRX+P`
int nFileLength = -1; v[DxWs8q
try{ xj]^<oi<
URL url = new URL(siteInfoBean.getSSiteURL()); 3^)c5kcI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #>z!ns
httpConnection.setRequestProperty("User-Agent","NetFox"); ;c@B+RquR
;<F^&/a|yQ
$p}q,f.
int responseCode=httpConnection.getResponseCode(); `lbRy($L
if(responseCode>=400) %w!x \UV
{ :;]O;RXt
processErrorCode(responseCode); %?/vC6
return -2; //-2 represent access is error s,|v,,<+
} W_ ;be
zSOZr2- ^a
SapVS*yx@
String sHeader; vZqW,GDfXo
cwHbm%
au+:-Khm
for(int i=1;;i++) fNrpYR X
{ ,a0RI<D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fQw=z$
//Utility.log(in.readLine()); Io/;+R.
sHeader=httpConnection.getHeaderFieldKey(i); gEgd/Le
if(sHeader!=null) 5RF*c,cNq
{ u0ZMrIJ
if(sHeader.equals("Content-Length")) U4iVI#f
{ *m'&<pg]X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ],zp~yVU&
break; AJoP3Zv|?
} TTo?BVBK
} {yxLL-5c
else O_DT7;g
break; #!(2@N8
} I;{Ua*
} IFtaoK
catch(IOException e){e.printStackTrace ();} {XnBj}C
catch(Exception e){e.printStackTrace ();} <#./q LSR
dL1{i,M
M pz9}[`3g
Utility.log(nFileLength); ZpwFC7LW
g/i.b&
wjKc!iB
return nFileLength; ')WS :\J
} GN+,9
iqWkhJphv
!|J2o8g
//保存下载信息（文件指针位置） J!QIMA4{
private void write_nPos() -(#`JT8
{ 4Le{|B
try{ qzu(4*Gk6
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3)(uC+?[
output.writeInt(nStartPos.length); vhU#<59a1
for(int i=0;i<nStartPos.length;i++) H.tfn>N|
{ /1+jQS
// output.writeLong(nPos); l5enlYH
output.writeLong(fileSplitterFetch.nStartPos); k/Q8:qA
output.writeLong(fileSplitterFetch.nEndPos); sv!6zJs
} #1'p?%K.
output.close(); Lr "V
} ciCQe]fS
catch(IOException e){e.printStackTrace ();} FaaxfcIfkw
catch(Exception e){e.printStackTrace ();} =<P$mFP2*
} 8xoC9!xt
K8v@)
raR=k!3i
//读取保存的下载信息（文件指针位置） 7?uIl9Vk>(
private void read_nPos() w:~vfdJ
{ :?)q"hE
try{ H[?l)nZ}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hu~XFRw15
int nCount = input.readInt(); Q_k'7Z\g$
nStartPos = new long[nCount]; iW[%|ddk
nEndPos = new long[nCount]; @A-E
for(int i=0;i<nStartPos.length;i++) z;&J9r$`
{ C&.Q|S2_
nStartPos = input.readLong(); QC1\Sn/
nEndPos = input.readLong(); 2FN#63
} ]];LA!n
input.close(); i06|P I
} T4;gF6(0]
catch(IOException e){e.printStackTrace ();} {CgF{7`
catch(Exception e){e.printStackTrace ();} U6YQ*%mZ_
} J(,{ -d-E
d(,M
Z3dI B`@
private void processErrorCode(int nErrorCode) ypTH=]y
{ hz-^9U
System.err.println("Error Code : " + nErrorCode); U@LIw6B!KL
} }l5Q0'
~yY5pnJ
V$ "]f6
//停止文件下载 UrdSo"%
public void siteStop() 1f$1~5Z
{ J c:j7}OOV
bStop = true; 5RKs2eV
for(int i=0;i<nStartPos.length;i++) 22EI`}"J
fileSplitterFetch.splitterStop(); b C"rQJg
6MQyr2c
{YIVi:4q
} L,sXJ23.
} 6 _#CvQ
//负责部分文件的抓取 z'Ut9u
**FileSplitterFetch.java #*+$o<Q]9
*/ fTi5Ej*/?)
package NetFox; $$T a
tG0 &0`
6+SaO !lR
import java.io.*; *nHkK!d<N
import java.net.*; ~[0^{$rrWs
n?v$C:jLN
}Gd^r
public class FileSplitterFetch extends Thread { rxeOT# N}
|#22pq?RP
bKr73S9
String sURL; //File URL '.XR,\g>
long nStartPos; //File Snippet Start Position wHs4~"EY9
long nEndPos; //File Snippet End Position R1Q~UX]d=
int nThreadID; //Thread's ID or[!C%
boolean bDownOver = false; //Downing is over F^cu!-L
boolean bStop = false; //Stop identical 41i#w;ojI
FileAccessI fileAccessI = null; //File Access interface OB+QVYk"
J/c5)IB|
8HDI]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^B(:Hv}G(:
{ Z07SK 'U
this.sURL = sURL; oox;8d4}y
this.nStartPos = nStart; ezhK[/E=
this.nEndPos = nEnd; LP}'upv
nThreadID = id; ({hW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ka8Bed3
} KY9@2JG
&hIr@Gi@ch
;@<e]Ft
public void run() _TVKvRh
{ if+97^Oy
while(nStartPos < nEndPos && !bStop) Yi|Nd;
{ Ne}x(uRn
ohPDknHp
mzn#4;m$
try{ W;.LN<bx
URL url = new URL(sURL); O/fm/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); er2#h
httpConnection.setRequestProperty("User-Agent","NetFox"); ifadnl26 s
String sProperty = "bytes="+nStartPos+"-"; >2#F5c67
httpConnection.setRequestProperty("RANGE",sProperty); v<gve<]
Utility.log(sProperty); BBj>ML\X
69zMWuY
w[/m:R?eX
InputStream input = httpConnection.getInputStream(); ^dKtUH/78G
//logResponseHead(httpConnection); lR5k1J1n
P?<G:]W
d-B,)$zE
byte[] b = new byte[1024]; j$r2=~1
int nRead; #$,b )Uy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =m?x5G^
{ 9*? i89T
nStartPos += fileAccessI.write(b,0,nRead); CD)JCv
//if(nThreadID == 1) {br6*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y2>AbrJ
} le~p2l#e
17!<8vIV$C
OsgjSJrf
Utility.log("Thread " + nThreadID + " is over!"); "E7YCZQR
bDownOver = true; ;Lk07+3G
//nPos = fileAccessI.write (b,0,nRead); ~lr,}K,
} _O`s;oc
catch(Exception e){e.printStackTrace ();} '-rRD\"q
} ]=(PtzVa
} +?GsIp@>jh
rpv<'$6
byX)4&
//打印回应的头信息 e0`5PVJ
public void logResponseHead(HttpURLConnection con) Vv*](iM
{ Z \;{e'#o
for(int i=1;;i++) 1raq;^e9
{ @gjA8mL
String header=con.getHeaderFieldKey(i); f SMy?8
if(header!=null) 7~nuFJaTI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0W]vK$\F*
Utility.log(header+" : "+con.getHeaderField(header)); /(DnMHn\
else &LHS<Nv^:
break; rWip[>^
} e9rgJJ
} }k_'a^;C1
!5>PZ{J
{,e-;2q
public void splitterStop() VH<-||X/4
{ .c\iKc#
bStop = true; *Jg&:(#}<J
} (vwKC D&
'_FxxLAO
r|Q/:UV?w
} `5MK(K :
6sNw#pqh
GyQvodqD
/* D[3QQT7c
**FileAccess.java &Yd6w}8
*//文件访问(定位，写) SX[
package NetFox; h|OWtf4
import java.io.*; `"y:/F"{
M^.>UZKyl
[s~6,wz
public class FileAccessI implements Serializable{ x+,:k=JMT
5a2+6N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NwNjB w%v
RandomAccessFile oSavedFile; FR6PY
long nPos; @J<RFgw#
&L r~x#Wx
]+T$D
public FileAccessI() throws IOException QQ./!
{ F?b"Rv
this("",0); =s,}@iqNO4
} q;QE(}.g
& DhdB0Hjf
.T#}3C/
public FileAccessI(String sName,long nPos) throws IOException E*d UJ.>
{ #S"s8wdD
oSavedFile = new RandomAccessFile(sName,"rw"); Ceew~n{
this.nPos = nPos; $ <Mf#.8%
oSavedFile.seek(nPos); jm,cVo
} Jj~|2Zt
.a9f)^
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public synchronized int write(byte[] b,int nStart,int nLen) LU+}iA)
{ Q 6dqFnz
int n = -1; a( SJ5t?-2
try{ NF'<8{~
oSavedFile.write(b,nStart,nLen); P 4+}<5
n = nLen; N,4hh?
} O[F
catch(IOException e) /&zlC{:G92
{ 1Hs'YzvY
e.printStackTrace (); 5.QY{+k
} Fmzkbt~oe
XUTsW,WC
o&>aYlXd
return n; 06[HE7
} ^m-w@0^z
#q6#nfi"
>O~
} lg*?w/JX+
hp}JKj@
DSK?7F$_oE
/* 3(_:"?xA
**SiteInfoBean.java ,6SzW+L7
*/ Ht|"91ZC5
package NetFox; :}-izd)/j
kzC4V
ogJ *
public class SiteInfoBean { $>rKm
+HlZ?1g
\Yh*ywwP#
private String sSiteURL; //Site's URL |g1Pr9{wy
private String sFilePath; //Saved File's Path I/go$@E"
private String sFileName; //Saved File's Name p;~oIy\,
private int nSplitter; //Count of Splited Downloading File .pIO<ZAFT
%$67*pY'JH
+NVXFjPC
public SiteInfoBean() `bF4/iBW
{//nSplitter的缺省值为5 0U?(EJ
//default value of nSplitter is 5 5RyxVC0<
this("","","",5); /ACau<U]t
} XHh*6Yt_ (
I!T=$Um
DSlO.)dHu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YmLpGqNv
{ .z^O y_S{
sSiteURL= sURL; ubMN
sFilePath = sPath; $4hi D;n
sFileName = sName; NKl`IiGv
this.nSplitter = nSpiltter; pRA%07?W
%JI*)K1WI
V,]Fh5f
} ?Cv([ ^Y.u
FIx|4[&>S
b(t8TR#-
public String getSSiteURL() H\$uRA oo*
{ -FW^fGS+
return sSiteURL; u-*z#e_L0
} `x;m@\R
c[Z#q*Q
G|TnvZ KX
public void setSSiteURL(String value) /z:1nq
{ o $'K}U
sSiteURL = value; 0S$TLbx
} ?RS4oJz,5g
eo^C[# .
wV\G$|Y
public String getSFilePath() #"fn;
{ Ok<,_yh
return sFilePath; j{6O:d6([$
} -B#K}xL|x
1 ]ePU8
m$7C{Mr'
public void setSFilePath(String value) yw{r:fy
{ ~zVe?(W
sFilePath = value; /#zs
} oA3;P]~[
gH*(1*
V=8npz
public String getSFileName() J[c`Qq:&e
{ rp|A88Q/!
return sFileName; 35L\
} q>.C5t'Qx
LIT`~D
NDJP`FI
public void setSFileName(String value) t:b}Mo0
{ W j`f^^\HJ
sFileName = value; @WiTh'w0
} t<"%m)J
&"7+k5O
$LiBJ~vV<
public int getNSplitter() .yD5>iBh
{ {7%(m|(
return nSplitter; G++<r7;x
} J0B*V0'zR
@U@O#+d'ZR
}zqo<o
public void setNSplitter(int nCount) 4BeHj~~
{ k{U[ U1j
nSplitter = nCount; )Br#R:#
} Lcf?VV}
} U2CC#,b!(
8fktk?|
ZD4aT1|Q7
/* x+b.9f4xJ
**Utility.java ~y"OyOi&
*/ 'S*]JZ1
package NetFox; lgZ9*@d
?Ezy0>j
wN^^_
public class Utility { Ao#bREm
P)LOAe1'
.[Qi4jm>`
public Utility() NE4]i
{ `I(ap{
|;&I$'i
K(HrwH`a{
} 'p@m`)Z
)0g!lCfb
//线程睡眠 `gyke2n
public static void sleep(int nSecond) /F6"uZSt4
{ .1z=VLKF'
try{ .zTkOkL
Thread.sleep(nSecond); Fk9]u^j
} f4&;l|R0a
catch(Exception e) yYSoJqj Q
{ 9e.$x%7j
e.printStackTrace (); ^%tn$4@@Z.
} %e)?Mem
} 5\h6'
J'tJY% `
//日志 T#i~/
public static void log(String sMsg) <":83RCS
{ .gt;:8fw{
System.err.println(sMsg); <j/wK]d*/
} HLQ> |,9
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T3LVn<Lm\
public static void log(int sMsg) *`LrvE@t
{ JSmg6l?[u
System.err.println(sMsg); c *<m.
} btC6R>0
} +KWO`WR
6/T/A+u
P&<NcOCL&
/* 'Gamb+[
**TestMethod.java $s-B
*/ %oquHkX%OJ
package NetFox; )>"pm{g2
wG6Oz2(
/Ak\Q5O'3
public class TestMethod { 5NhAb$q2Y
U#Iwe=
0C\cM92o
public TestMethod() 2##mVEo.(
{ ///xx/weblogic60b2_win.exe 'Yh`B8
try{ yu&muCA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zg0nsNA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $!TMS&Wk
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4mtO"'|
fileFetch.start(); ?$uEN_1O\@
} rixVIfVF
catch(Exception e){e.printStackTrace ();} -$_FKny
B-$zioZ
wXZ9@(^
} W~a|AU8]C
eu~ u-}.
~%eE%5!k
public static void main(String[] args) O(v>\MV
{ B9$pG
new TestMethod(); @&%/<|4P5
} :UAcS^n7h"
} 7I@df.rf6J
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