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)); C=,O'U(ep
} m[8?d~
for(int i=0;i<nEndPos.length-1;i++) oj%(@6L
{ O3~7
nEndPos = nStartPos[i+1]; X(M|T]`b:
} mGP&NOR0^y
nEndPos[nEndPos.length-1] = nFileLength; /k^!hI"4c
} ZBsV
} PSREQK@}E
Cr>YpWm
!&#5*
//启动子线程 9gQ ]!Oq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VbfTdRD-
for(int i=0;i<nStartPos.length;i++) wzf%~ats
{ "rU 2g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }=$>w@mJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v4Mn@e_#c
nStartPos,nEndPos,i); >eM>Y@8=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0f9*=c
fileSplitterFetch.start(); 1WUlBr/k
} -F`uz,wZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P={8qln,X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ul^VGW>i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |] cFsB#G
nEndPos = " + nFileLength); :878q TB
// fileSplitterFetch[nPos.length-1].start(); K'U8ft*_
&e)V!o@wJV
P&sYS<9q
//等待子线程结束 B2T=O%
//int count = 0; [DD#YL\P
//是否结束while循环 lcfX(~/m^
boolean breakWhile = false; sg%Ptp
N:~CN1
SL5QhP
while(!bStop) `"h[Xb#A`b
{ we&D"V
write_nPos(); cH6<'W{*
Utility.sleep(500); +<rWYF(ii/
breakWhile = true; Gc,6;!+(
"Ta"5XW
iCIU'yI
for(int i=0;i<nStartPos.length;i++) Ye]-RN/W
{ [yx8?5
if(!fileSplitterFetch.bDownOver) %_. fEFy07
{ @FaK/lKK
breakWhile = false; |3P dlIbO
break; 0P l>k'9
} 7p_B?r
} ^,{ r[}
if(breakWhile) 3A!Qu$r9
break; )MeeF-Ad6
O#n=mJ
dM)x|b3z
//count++; ;5&=I|xqe
//if(count>4) S+7u,%n/
// siteStop(); Z3O_K
} Lq]t6o]
r^T+I3
jX&/ e'B
System.err.println("文件下载结束！"); fb?YDM
} 2bAH)=
catch(Exception e){e.printStackTrace ();} M$Ow*!DfP
} wo5fGQJ
=^mBj?(V7
h@jk3J9^
//获得文件长度 j^m x,
public long getFileSize() N?v}\PU
{ MnTqWC90
int nFileLength = -1; !0X/^Xv@=
try{ #b>D^=NV>)
URL url = new URL(siteInfoBean.getSSiteURL()); p-kug]qX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e/R$Sfj]
httpConnection.setRequestProperty("User-Agent","NetFox"); UTVqoCHA
1otE:bi
-0>s`ruor
int responseCode=httpConnection.getResponseCode(); @+yjt'B
if(responseCode>=400) 85vyt/.,k
{ P~h0Ul
processErrorCode(responseCode); gB])@O%/
return -2; //-2 represent access is error u9j1>QU
} `{H!V~42
Ntlbn&lc;D
i|!W;2KL5
String sHeader; qlC4&82=Q
.o)
Sz-TarTF
for(int i=1;;i++) PQXCT|iJ
{ q0KGI/5s4+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bKQ_{cR
//Utility.log(in.readLine()); BHpj_LB-P
sHeader=httpConnection.getHeaderFieldKey(i); r#B{j$Rw
if(sHeader!=null) juEH$7N!
{ C}]143a/Q
if(sHeader.equals("Content-Length")) IgEVz^W?h
{ I[KAW"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eE" *c>I
break; 2`A\'SM'4
} AA5UOg\jI
} Bpp(5
else WDF6.i ?
break; ]F srk
} Q*8efzgs|
} Ws:+P~8
catch(IOException e){e.printStackTrace ();} 7T?T0x3>
catch(Exception e){e.printStackTrace ();} MCTTm^8O
?OC&=}
d RHw]!.
Utility.log(nFileLength); a0PClbf2.
8gW$\
JfzfxfM
return nFileLength; K~A@>~vFb
} %<\tN^rP
Id{Ix(O
~;@\9oPpz%
//保存下载信息（文件指针位置） yAQ)/u[|
private void write_nPos() G$t:#2
{ R<Ct{f!
try{ vu3zZMl
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6\RZ[gA?
output.writeInt(nStartPos.length); w_*$wVl
for(int i=0;i<nStartPos.length;i++) &{S@v9~IT
{ b q8nV
// output.writeLong(nPos); ,"Nb;Yhg
output.writeLong(fileSplitterFetch.nStartPos); wLKC6@ W
output.writeLong(fileSplitterFetch.nEndPos); 3+8{Y
} ?'U@oz8 B
output.close(); y6&o+;I$[
} gM&4Ur
catch(IOException e){e.printStackTrace ();} ?3do-tTp
catch(Exception e){e.printStackTrace ();} h%&2M58:
} K<p)-q
!_?#f|
u(~(+1W
//读取保存的下载信息（文件指针位置） !BR@"%hx
private void read_nPos() &"=<w
{ %Vhj<gN
try{ Thuwme
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9G)fJr[c
int nCount = input.readInt(); xpWY4Q
nStartPos = new long[nCount]; &G_XgQsg{
nEndPos = new long[nCount]; e|4U2\&3y
for(int i=0;i<nStartPos.length;i++) i}~U/.P
{ \N.Bx
nStartPos = input.readLong(); 'h>CgR^NM1
nEndPos = input.readLong(); 41c4Xj?'
} cD9.L
input.close(); qjH/E6GGg
} C:RA(
catch(IOException e){e.printStackTrace ();} \iAs
catch(Exception e){e.printStackTrace ();} C,,S<=L:
} 8[x{]l[
rGQY
nxs'qX(D
private void processErrorCode(int nErrorCode) CPJ%<+4%b
{ jR"ACup(
System.err.println("Error Code : " + nErrorCode); <1E5[9 q
} _@O.EksY3r
90">l^HX=
\'+P5,
//停止文件下载 r[3 2'E
public void siteStop() Iy@6cd,)S
{ )@6iQ
bStop = true; w5q'M
for(int i=0;i<nStartPos.length;i++) FLQ>,=O
fileSplitterFetch.splitterStop(); 4^k+wQU
a>egH og
)b-KF}]d
} :</KgR0I
} K5 Z'kkOk
//负责部分文件的抓取 AX6l=jFZx
**FileSplitterFetch.java BCt>P?,UO
*/ -fDW>]_
package NetFox; RH"EO4
.:iO$wjp5
#{zF~/Qq
import java.io.*; +[Q`I*C
import java.net.*; ML7qrc;Rx
d8VFa'|
b\C1qM4
public class FileSplitterFetch extends Thread { ~/;shs<9EM
`Lr|KuFN
#./8inbG
String sURL; //File URL }M &hcw<
long nStartPos; //File Snippet Start Position 1 Lz
long nEndPos; //File Snippet End Position Y"E*#1/
int nThreadID; //Thread's ID ,ZvlKN
boolean bDownOver = false; //Downing is over _nec6=S6(
boolean bStop = false; //Stop identical Qo+Y
FileAccessI fileAccessI = null; //File Access interface wcW}Sv[r
ZC9S0Z
CFG(4IMx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tTPjCl
{ I~25}(IDZ"
this.sURL = sURL; ]_2<uK}fg
this.nStartPos = nStart; r-5xo.J'
this.nEndPos = nEnd; _Q}vPSJviC
nThreadID = id; sLW e \o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _q`f5*Z[
} >H,PST
*[tLwl.
Q=#Wk$1.
public void run() *zWf8X
{ j4E`O%@^
while(nStartPos < nEndPos && !bStop) #XeabcOQ
{ LR y&/d
0yL%Pjn6
#w;%{C[D
try{ fU'[lZ
URL url = new URL(sURL); B)s%B'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :{~TG]4M
httpConnection.setRequestProperty("User-Agent","NetFox"); <ugy-vSv
String sProperty = "bytes="+nStartPos+"-"; tFX!s;N[
httpConnection.setRequestProperty("RANGE",sProperty); WP4"$W
Utility.log(sProperty); ,pa=OF
#A^(1
XvkFP'%i/
InputStream input = httpConnection.getInputStream(); )0{ZZ-beG
//logResponseHead(httpConnection); y@\J7 h:
2UEjn>2
VP:9&?>G
byte[] b = new byte[1024]; [\.@,Y0j
int nRead; 7z3YzQ=Kg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C^ Oy.s
{ N@R?<a
nStartPos += fileAccessI.write(b,0,nRead); +EM^
//if(nThreadID == 1) UKf0cU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?xtP\~
} xU'% 6/G
V)cL=4G
`<* tp@
Utility.log("Thread " + nThreadID + " is over!"); U46Z~B
bDownOver = true; -qJO6OM
//nPos = fileAccessI.write (b,0,nRead); Il$Jj-)
} 8Oo16LPD
catch(Exception e){e.printStackTrace ();} ^q/_D%]C
} N6!$V7oT
} }RZN3U=
AI2@VvB
Kl w9
//打印回应的头信息 -PskUl'
public void logResponseHead(HttpURLConnection con) Cm#[$T@C
{ rIJd(=
for(int i=1;;i++) }N W01nee
{ BS+=*3J
String header=con.getHeaderFieldKey(i); "ac$S9@~
if(header!=null) @fI2ZWN|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cGS7s 8U
Utility.log(header+" : "+con.getHeaderField(header)); >jpkR
else 3Hkb)Wu
break; AR7]~+X
} 9v(k<('_
} 01vKx)f
Io7o*::6iw
N3?hu}
public void splitterStop() u51Lp
{ 'SnB7Y
bStop = true; }vt>}%%
} 4i(?5p>f
#\gx.2W7
}Z8DVTpX}
} GA2kg7
YY 8vhnw
OsNJ;B
/* %lSjC%Z'd
**FileAccess.java f}VIkx]X"
*//文件访问(定位，写) Mt%=z9OLq9
package NetFox; lAo S 9w
import java.io.*; ++Fk8R/$U[
6}GcMhU<r
;BYv&(#u1q
public class FileAccessI implements Serializable{ @Jr@ fF}
?a'P;&@7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #]lK!:
RandomAccessFile oSavedFile; ]%I|C++0
long nPos; Bngvm9k3
CL<m+dW%*
xc_-1u4a9
public FileAccessI() throws IOException TV*@h2C"i
{ E{}Vi>@V?
this("",0); 287)\FU;3
} jQ9i<-zc
uui3jZ:
,w0Io
public FileAccessI(String sName,long nPos) throws IOException lW3wmSWn%
{ d@>1m:p
oSavedFile = new RandomAccessFile(sName,"rw"); |RZI]H%
this.nPos = nPos; zOA2chy4
oSavedFile.seek(nPos); m$B)_WW
} L~e{Vv8UR
<,I]=+A
}g_\?z3gt
public synchronized int write(byte[] b,int nStart,int nLen) C^nTLw;K
{ SX@zDuM
int n = -1; <F-W fR
try{ $gysy!2}.
oSavedFile.write(b,nStart,nLen); ]%Z7wF</
n = nLen; pX]"^f1?O
} ~oE@y6Q
catch(IOException e) ^4[|&E:
{ v7G&`4~
e.printStackTrace (); c<]~q1
} S)vNWBO
=SLCG.
hO0g3^
return n; G~KYFNHr
} f/{*v4!
A,]%*kg2
6tv-PgZ
} ioJr2wq6
Z^r? MX/
x0$#8
/* (?lKedA>2
**SiteInfoBean.java zb& 3{,
*/ .Fm@OQr
package NetFox; L2\NTNY
jRNDi_u?Wb
^Bu55q
public class SiteInfoBean { ~dlpoT
U['|t<^uf
iuS*Vw
private String sSiteURL; //Site's URL c@/K}
private String sFilePath; //Saved File's Path FgTWym_
private String sFileName; //Saved File's Name ~(K{D D7[N
private int nSplitter; //Count of Splited Downloading File #D|n6[Y'.t
E>Lgf&R#W
'O[0oi&
public SiteInfoBean() 'rDai[
{//nSplitter的缺省值为5 p-JGDjR0G
//default value of nSplitter is 5 8KHT"uc'*J
this("","","",5); -8m3L
} 9q_c`
0=Mu|G|Z
_FtsO<p)"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QI*<MF,1
{ 1AAOg+Y@U"
sSiteURL= sURL; Sgq?r-Q.
sFilePath = sPath; sglH=0MP
sFileName = sName; i:\|G^h
this.nSplitter = nSpiltter; aDZ]{;
MeW?z|x`'
u?I2|}#
} l" +q&3Zx
.T\_4C
@23~)uiZa
public String getSSiteURL() R/Z zmb{
{ d34BJ<
return sSiteURL; <#~n5W{l
} *^[j6
/a?qtRw
-~v1@
public void setSSiteURL(String value) &AP`k
{ *I9O+/,
sSiteURL = value; dq^vK
} +a0` ,Jc
")@#B=8+3^
e"&QQ-q
public String getSFilePath() njckPpyb@
{ M$UZn
return sFilePath; aDda&RM
} uS7kkzt-x
_(F8}s
ubUVxYD?
public void setSFilePath(String value) ]8CgHT[^7
{ y7| 3]>Z
sFilePath = value; S pk8u4
} xq<X:\O
cV:Ak~PKl
|&U{ z?
public String getSFileName() 2B"&WKk
{ frT<9$QUL
return sFileName; &gsBbQ+qA
} p> g[: ~
vW4n>h}]
AL;4-(KH
public void setSFileName(String value) %uDH_J|^
{ "NtY[sT{V
sFileName = value; }56WAP}Z 4
} >)+N$EN
58P[EMhL
xQkvK=~$
public int getNSplitter() a!B"WNb+
{ CN:z *g
return nSplitter; ;@xlrj+
} '8=/v*j>?
:*Y2na)qQ
.I.B,wH8
public void setNSplitter(int nCount) kxmc2RH>nB
{ "/Pq/\,R|
nSplitter = nCount; "{[\VsX|c
} gUY~ l= c
} u6SQq-)d
8]Q#P
*USG p<iH
/* LB`{35b-
**Utility.java yt<h!k$ _P
*/ V.Tn1i-v
package NetFox; =YY 7V!
-\n%K
&%m%b5
public class Utility { es<8"CcP
:l&Yq!5
Bk[C=<X
public Utility() 0+e
{ e, fZ>EJ
sLUOs]cj
+t3o5&
} ~*x 2IPiH
et?FX K"y
//线程睡眠 wf`A&P5tF
public static void sleep(int nSecond) d,toUI
{ <Xw\:5 F<7
try{ EjMVlZC>
Thread.sleep(nSecond); :C2 @!W z
} 5XV|*O;
catch(Exception e) p6!5}dD(
{ t&Q(8Hz
e.printStackTrace (); t YxN^VqU
} O_]hbXV0
} Ec@cW6g(%
&gKDw!al
//日志 qw1W}+~g
public static void log(String sMsg) #k?.dWZ!
{ tQas_K5
System.err.println(sMsg); KWojMPs
} RLZfXXMn
|<'6rJ[i>
[>t;P,
public static void log(int sMsg) YmOj.Q&
{ ea]qX6)UZ
System.err.println(sMsg); %z=:P{0UQ
} ka6E s~
} %-a;HGbZn
`mA;1S
FPH2dN
/* p]ujip
**TestMethod.java (;&}\OX6nm
*/ KIp^| k7>
package NetFox; lX.-qCV"B
3dlY_z=0
No)0|C8:
public class TestMethod { at4JLbk
D,Gv nfY
h3-^RE5\`S
public TestMethod() -+Ot'^
{ ///xx/weblogic60b2_win.exe tDRo)z
try{ d%.|MAE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ="v`W'Pd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O-[
SiteFileFetch fileFetch = new SiteFileFetch(bean); "{\xBX~oM
fileFetch.start(); {Wi*B(
} 7'"qW"<
catch(Exception e){e.printStackTrace ();} ptrwZ8'
4wkv#vi7!-
:)i,K>y3i
} NU3TXO
z~3GgR"1d
`+rwx
public static void main(String[] args) 5:jme$BI
{ Arm'0)B>
new TestMethod(); cc3B}^@p=
} /(*Ucv2i}T
} Wy}^5]R0E
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