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)); 6+PGwCS
} Gru ALx7
for(int i=0;i<nEndPos.length-1;i++) '[fZt#
{ RL&lKHA
nEndPos = nStartPos[i+1]; XTo8,'UaP
} ~:Mm<*lL%
nEndPos[nEndPos.length-1] = nFileLength; HJ@5B"
} vGN3 YcH
} %wL,v.}
2C1+_IL
MZ~.(&
//启动子线程 (.Xr#;\(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z %EQt
for(int i=0;i<nStartPos.length;i++) #{,h@g}W
{ ~ 5"J(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ipZHSA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 784;]wdy\
nStartPos,nEndPos,i); f:vD`Fz1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sFElD ]|
fileSplitterFetch.start(); *P xf#X
} ~6d5zI4\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H\+-cvl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @T7PZB&xnl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [H^ X"D
nEndPos = " + nFileLength); 968^"T#
// fileSplitterFetch[nPos.length-1].start(); 9h&yuS'Yj
N-QCfDao
sN]Z #7
//等待子线程结束 7\%$>< K
//int count = 0; W~NYU
//是否结束while循环 MaErx\
boolean breakWhile = false; P)1EA;
&7Kb]Ti
]^'ZiyJX
while(!bStop) Qlh?iA
{ xb`CdtG2.
write_nPos(); |yv]Y/=
Utility.sleep(500); O`(U/?
breakWhile = true; =4>@8=JA
r*Z_+a8
iZC`z }
for(int i=0;i<nStartPos.length;i++) 6b#~;
{ P` ]ps?l
if(!fileSplitterFetch.bDownOver) oHsP?%U
{ hr~.Lj5^W
breakWhile = false; Cuv|6t75'
break; q+%!<]7X
} sam[s4@eQ
} WZK :.y
if(breakWhile) Z= ik{/
break; ,`)OEI|1d
VIg\]%qse
gh61H:tkR
//count++; vJThU$s-
//if(count>4) e~ BJvZ}Q
// siteStop(); 7LdzZS0OM
} K?YEoz'y[
]}~4J.Yn
Tk](eQsy.v
System.err.println("文件下载结束！"); b9#m m
} 0_HJ.g!
catch(Exception e){e.printStackTrace ();} BA*&N>a
} :D4];d>1
e^WqJ7j
H &fTh
//获得文件长度 %omu
public long getFileSize() :`5;nl63
{ r\RFDj
int nFileLength = -1; 453 }S
try{ D2$^"
URL url = new URL(siteInfoBean.getSSiteURL()); mtX31M4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y($EK(cb
httpConnection.setRequestProperty("User-Agent","NetFox"); wPQ&Di*X}
s9 &)Fv-#V
z L8J`W
int responseCode=httpConnection.getResponseCode(); I1i:}g/
if(responseCode>=400) oN ;-M-(
{ Hh\ 4MNl
processErrorCode(responseCode); ?sE@]]z
return -2; //-2 represent access is error W1`Dx(g
} 4znH$M>bU
$E@ouX?
j@CKO cn2
String sHeader; yWmrdvL
Cy6%S).c
XD 5n]AL
for(int i=1;;i++) Wt"ww~h`(
{ Q-3r}jJe
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T?#s'd
//Utility.log(in.readLine()); LS{bg.e
sHeader=httpConnection.getHeaderFieldKey(i); 3l$E8?[Zwi
if(sHeader!=null) gY%OhYtF2
{ }Zt.*%
if(sHeader.equals("Content-Length")) "&Gw1.p
{ #)FDl70S8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @Jm.HST#S8
break; J ZA*{n2
} 'H!V54 \j
} !"`Jqs
else aU4R+.M7@
break; ^glX1 )
} m^'~&!ba
} rykj2/O
catch(IOException e){e.printStackTrace ();} f&f`J/(
catch(Exception e){e.printStackTrace ();} %pH)paRAP
C/bxfp{?
sbgJw
Utility.log(nFileLength); Etw~*
El{r$-}
J}:&eS
return nFileLength; D/e&7^iK
} 40R"^*
=,O/,2)
(X*'y*:
//保存下载信息（文件指针位置） :MK:TJV
private void write_nPos() >B`Cch/'U
{ hI*`>9l
try{ 8~;{xYN )
output = new DataOutputStream(new FileOutputStream(tmpFile)); U&`6&$]
output.writeInt(nStartPos.length); hH#lTye
for(int i=0;i<nStartPos.length;i++) eU`;L[
{ )4@M`8
// output.writeLong(nPos); q)NXyy4BT
output.writeLong(fileSplitterFetch.nStartPos); =[s8q2V
output.writeLong(fileSplitterFetch.nEndPos); *3!(*F@M,
} EN)YoVk
output.close(); NWw<B3aL
} 04P.p6
catch(IOException e){e.printStackTrace ();} K*TnUQ
catch(Exception e){e.printStackTrace ();} C?8PT/
} O5ucI$s
m\_+)eI|
LFl2uV"
//读取保存的下载信息（文件指针位置） *@CVYJ'<
private void read_nPos() !&qx7eOSpP
{ +d.u##$
try{ Rk}\)r\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W&HF?w}s
int nCount = input.readInt(); ,<7"K&
nStartPos = new long[nCount]; f+{c1fb>s
nEndPos = new long[nCount]; qi(&8in
for(int i=0;i<nStartPos.length;i++) {F<)z%^
{ \)FeuLGL9
nStartPos = input.readLong(); t-'I`I
nEndPos = input.readLong(); Tnf&pu#5
} yZ?xt'tn
input.close(); :8](&B68gE
} pTc$+Z73
catch(IOException e){e.printStackTrace ();} {k kAqJ
catch(Exception e){e.printStackTrace ();} eVJ= .?r
} CR%D\I$o
mYntU^4f
yb[{aL^4%
private void processErrorCode(int nErrorCode) lq;
{ d&/^34gn
System.err.println("Error Code : " + nErrorCode); 3X,]=f@_
} ue,#,3{m
~D<7W4c
f+*J ue
//停止文件下载 `)0Rv|?
public void siteStop() 1[26w_B3
{ kEp.0wL'
bStop = true; ,h3269$J
for(int i=0;i<nStartPos.length;i++) H|grbTv,
fileSplitterFetch.splitterStop(); eV"dv*R
d\v$%0
^`l"'6
} ev~dsk6k
} 6XQ*:N/4al
//负责部分文件的抓取 D=jSh
**FileSplitterFetch.java q>Q:X3
*/ 8:Z@lp^
package NetFox; <8}KEe4
Dm7Y#)%8
Zkf 3t>[
import java.io.*; pem3G5 `g=
import java.net.*; ZC3tbhV
9V|E1-")E
/X(@|tk:
public class FileSplitterFetch extends Thread { hB|H9+
:iP>z}h
v_y!Oh?EG
String sURL; //File URL +AE&GU
long nStartPos; //File Snippet Start Position Gg 7WmL
long nEndPos; //File Snippet End Position UN cYu9[
int nThreadID; //Thread's ID `,F&y{A
boolean bDownOver = false; //Downing is over Q%M'[L?[
boolean bStop = false; //Stop identical BP)q6?Mz
FileAccessI fileAccessI = null; //File Access interface k98< s
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xi '72
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bBkm] >
{ [W^6u7~
this.sURL = sURL; (|yRo
this.nStartPos = nStart; '5|Q<5!o
this.nEndPos = nEnd; LydbP17K}
nThreadID = id; &"U9X"8b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 />dB%*
} kx"hWG4
3v8V*48B$
#6Efev
public void run() P<j4\zJ
{ {]t\`fjrg
while(nStartPos < nEndPos && !bStop) 5~_eN
{ SREDM
e5*5.AB6&
|i,zY{GI+2
try{ W~XV
URL url = new URL(sURL); blKDQ~T2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c,v^A+sZu
httpConnection.setRequestProperty("User-Agent","NetFox"); =yk Rki
String sProperty = "bytes="+nStartPos+"-"; QLn5#x~xb
httpConnection.setRequestProperty("RANGE",sProperty); )bB"12Z|8
Utility.log(sProperty); }<( "0jC
l _kg3e4
"_ PH"W
InputStream input = httpConnection.getInputStream(); { 4_I7r
//logResponseHead(httpConnection); }aHB$}"!
C?GvTc
6=Y3(#Ddt
byte[] b = new byte[1024]; ?6gDbE%
int nRead; 2]of SdM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P.[6s$J
{ "4Vi=*2V
nStartPos += fileAccessI.write(b,0,nRead); z")3_5Br
//if(nThreadID == 1) ifJv~asp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .c=$ bQ>^
} WL IDw@fv
cM> G>Yzo
OCbQB5k3
Utility.log("Thread " + nThreadID + " is over!"); 7AGZu?1]M
bDownOver = true; [M7iJcwt
//nPos = fileAccessI.write (b,0,nRead); rQd1Ch
} tMD^$E"C
catch(Exception e){e.printStackTrace ();} 6i9Q,4~
} fd!pM4"0
} OBKC$e6I
%8Z|/LGg
!^Z[z[
//打印回应的头信息 |kBg8).B
public void logResponseHead(HttpURLConnection con) EO o'a
{ sUyCAKebRr
for(int i=1;;i++) mFgb_Cd
{ C,OB3y
String header=con.getHeaderFieldKey(i); z._C*c
if(header!=null) c"f-$^<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K%[}[.cW
Utility.log(header+" : "+con.getHeaderField(header)); r 48;_4d)D
else ~WYE"(
break; a>)_ `m
} {|Mxvp*Hg
} V:,3OLL*
,%)WT>
9:CVN@E
public void splitterStop() tKs4}vW
{ Gg}LC+Y
bStop = true; UijuJ(Tle
} bOdsMlJkN
cdek^/
HonAK
} Ru9pb~K
PoBukOv
A3 Rm0
/* DMK"Q#Vw
**FileAccess.java %~B)~|h
*//文件访问(定位，写) hZss
package NetFox; 4Rrw8Bw
import java.io.*; BZ\EqB
*mK);@pL
Vne.HFXA
public class FileAccessI implements Serializable{ 8eS@<[[F#
fUL{c,7xda
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $:-= >
RandomAccessFile oSavedFile; ',J%Mv>Yf
long nPos; eHnei F
)K\k6HC.
<Hr@~<@~
public FileAccessI() throws IOException My6]k?;}(
{ yNWbI0a
this("",0); 1CS]~1Yp:
} Op$J"R
_!CvtUU0Vv
qG2\`+v
public FileAccessI(String sName,long nPos) throws IOException gE6y&a
{ JI[rIL\Ey
oSavedFile = new RandomAccessFile(sName,"rw"); 9TXm Z
this.nPos = nPos; {C0OrO2:
oSavedFile.seek(nPos); &' Nk2{
} !3X%5=#L4
v;F+fOo
t-<[._:+
public synchronized int write(byte[] b,int nStart,int nLen) whg4o|p
{ )H37a
int n = -1; Med"dHo7
try{ lA^Kh
oSavedFile.write(b,nStart,nLen); k`4\.m"&
n = nLen; |z<wPJ,;2
} 7N~qg 7&
catch(IOException e) B|q3;P
{ -I$txa/"|
e.printStackTrace (); <GFB'`L
} -m x3^
;~1/eF
W!Ct[t
return n; C;:1CK
} fPk9(X;G!p
WCfe!P?g
,IVr4#w0=
} &LxzAL,3!
d[Fr
j n&9<"W
/* ;Q,).@<C
**SiteInfoBean.java j BQqpFH9
*/ 4oaP"T@6
package NetFox; "y ,(9_#
hjp?/i%TQ
eS# 0-
public class SiteInfoBean { \3Ald.EqtM
W2.1xNWO
[Oy2&C
private String sSiteURL; //Site's URL h}:5hi Jw
private String sFilePath; //Saved File's Path +&zuI
private String sFileName; //Saved File's Name K'rs9v"K|
private int nSplitter; //Count of Splited Downloading File [t=+$pf(-
9kg>)ty@
u$/2XO
public SiteInfoBean() 8Carg~T@
{//nSplitter的缺省值为5 ^l2d?v8
//default value of nSplitter is 5 d=OO(sf
this("","","",5); Hr,gV2n
} 4y}a,
te4"+[ $|
iuk8c.TAR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *M!YQ<7G^d
{ ^EBM;&;7
sSiteURL= sURL; 6o23#JgN
sFilePath = sPath; 3)MM5 bb$
sFileName = sName; "N:]d*A\
this.nSplitter = nSpiltter; 7ofH@U
PaI63 !
>33b@)
} <EN[s
"uERa(i
7XC}C+
public String getSSiteURL() [&kk
{ #K*q(ei,7h
return sSiteURL; m<LzB_G\
} gY^TBR0?m
kT=|tQ@
"1TM
public void setSSiteURL(String value) {j4:.fD
{ krY.Cc]
sSiteURL = value; \J g#X:d
} F7u%oLjr
>h-6B=
2Sd6b 2-
public String getSFilePath() ]1$AAmQH
{ x(6.W"-S
return sFilePath; JV{!Ukuyp+
} /FZ )ej\
&I_!&m~
s/|'1E\F
public void setSFilePath(String value) ebwoMG,B-
{ I,Y^_(JW
sFilePath = value; QN5N hs
} 0`zq*OQ
v"TH[}C9D
%Ne>'252y
public String getSFileName() Ybiz]1d
{ J, U~.c
return sFileName; .tZ$a_O
} !Bbwl-e`
f3|=T8"t
{%}6d~Bg
public void setSFileName(String value) 4B>|Wft{p]
{ Lh$ac-Ct
sFileName = value; 0n^j 50Yq
} v^E2!X
=v"{EmT[$
Z4sjH1W
public int getNSplitter() vxZUtyJfe
{ ;8kfgpM_
return nSplitter; o: DnZN
} I#e*,#'S
gvt4'kp
#>NZN1
public void setNSplitter(int nCount) +6E<+-N
{ h"m7r4f
nSplitter = nCount; 'm((G4
} ;:1mv
} @isqFKjph
JYUKs~Qt
~kFRy{z
/* ZXkAw sr
**Utility.java Stx-(Kfn4
*/ 5lY9
package NetFox; ^jC0S[csw2
|Q+v6r(<zZ
2AE|N_v8W
public class Utility { k{8N@&D
v:b%G?o
L1+cv;t
public Utility() |a3b2x,
{ ?!vW&KJZx
=]Bm>67"
H[oi? {L
} }DwXs`M7
Jl}7]cVq#
//线程睡眠 Fv B2y8&W
public static void sleep(int nSecond) }])f^
{ CiFbk&-g
try{ v]sGdZ(6-
Thread.sleep(nSecond); O^hV<+CX
} %J'_c|EQM
catch(Exception e) c Ix(;[U
{ O%{>Zo_<
e.printStackTrace (); !b_IH0]U
} ^.7xu/T
} =cY]cPO
nwYeOa/t
//日志 .d,Zx
public static void log(String sMsg) b87d'# .
{ R/7l2*
System.err.println(sMsg); }qg&2M%\
} )LUl?
cQ%HwYn
"tIx$?I
public static void log(int sMsg) OYkd?LN
{ JKGZ0yn
System.err.println(sMsg); IuL]V TY
} vJs/ett
} $6[]c)(
"k/x+%!Spc
oc3/ IWII
/* ubw ]}sfM#
**TestMethod.java ?T"crX
*/ >'eqOZM
package NetFox; 1zffPC8jl
0%GWc}o
EOiKwhrV
public class TestMethod { 8,Z0J
+( d2hSIF
*Bj G3Jc5
public TestMethod() ueOvBFgZ
{ ///xx/weblogic60b2_win.exe 4KKNw9L)
try{ !E8JpE|z#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U7N<!6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2t'&7>Ys{
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?bEYvHAzg
fileFetch.start(); 0#ph1a<
} POf \l
catch(Exception e){e.printStackTrace ();} k dqH36&<
\]D;HR`vo
b]~M$y60q
} >;Bhl|r~z
QZY(S*Up
UTz;Sw?~hw
public static void main(String[] args) VQCPgs
{ j8b:+io
new TestMethod(); @UA>6F
} xFJ>s-g*
} `u-}E9{
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