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)); sX]ru^F3
} &uxwz@RC0
for(int i=0;i<nEndPos.length-1;i++) mTZgvPJ!
{ \E,Fe:/g
nEndPos = nStartPos[i+1]; ^/jALA9!
} ipJnNy;
nEndPos[nEndPos.length-1] = nFileLength; H_7X%TvXb
} si|b>R&Z
} 3EX41)u
G8F43!<
O\zGN/!
//启动子线程 4vf,RjB-5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b{lkl?@a
for(int i=0;i<nStartPos.length;i++) df!n.&\y!
{ AME6Zu3Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qGKQrb,K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S-)%#
nStartPos,nEndPos,i); x2H?B`5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x0x/2re
fileSplitterFetch.start(); &B>YiA
} 3}X;WE `
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )6Qk|gIu(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OcGHMGdn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4)~GHb
nEndPos = " + nFileLength); X8=sk
// fileSplitterFetch[nPos.length-1].start(); -(+/u .
&l NHNu[
XxEKv=_bc
//等待子线程结束 6z80Y*|eJ
//int count = 0; 3re|=_ Hy
//是否结束while循环 '74-rL:i
boolean breakWhile = false; N5:muh \
y~pJ|E
_<1uO=km6
while(!bStop) ^gD%#3>X
{ B?)=d,E
write_nPos(); 4`#3p@-
Utility.sleep(500); E>3fk
breakWhile = true; &r Lg/UEV-
ONw;NaE,
*PJg~F%
for(int i=0;i<nStartPos.length;i++) '@<aS?@!t
{ T5+iX`#M
if(!fileSplitterFetch.bDownOver) yPqZ ,
{ P7i G,i
breakWhile = false; (S[" ak
break; $}G03G@
} <H)I06];
} )m Uc !TP
if(breakWhile) F!;0eS"xp
break; U ExK|t
6T5nr
`9
//count++; 1&@s2ee4
//if(count>4) 9\]%N;;Lo
// siteStop(); <([1(SY2e
} |NcfR"[c
jK^'s6i#
\=yx~c_$L
System.err.println("文件下载结束！"); D$RQD{*
} {1y-*@yU(
catch(Exception e){e.printStackTrace ();} !v2D 18(
} IZ;%lV7t
FSqS]6b3
U. 1Vpfy
//获得文件长度 Ny>tJ~I
public long getFileSize() T/"6iv\1
{ ~5HI9A4^
int nFileLength = -1; c D+IMlT
try{ rZDlPp>BPZ
URL url = new URL(siteInfoBean.getSSiteURL()); c%aY6dQG&%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dE+xU(\,w
httpConnection.setRequestProperty("User-Agent","NetFox"); 05\A7.iy
)j40hrR
;K:)R_H
int responseCode=httpConnection.getResponseCode(); ~h] <E
if(responseCode>=400) g(\FG
{ pC2r{-
processErrorCode(responseCode); \d0R&vFHQ
return -2; //-2 represent access is error 6=kA
} t]Xdzy
i6zfr|`@
%v\0Dm+A
String sHeader; Vc3tKuMsiX
;f7(d\=y
M$z.S0"
for(int i=1;;i++) wj/\!V!
{ cjU*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m<wng2`NTv
//Utility.log(in.readLine()); d_&R>GmR$
sHeader=httpConnection.getHeaderFieldKey(i); *r)/.rK_
if(sHeader!=null) u{'bd;.7
{ B~cQl
if(sHeader.equals("Content-Length")) #J]u3*Tn|
{ ?5nF` [rx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^o]ZDc
break; 7z"xjA
} 1Fn+nDnO6
} Z&%#,0>]
else >C~-*M9
break; }\`MXh's
} `'[u%UE
} p6]4YGw*^
catch(IOException e){e.printStackTrace ();} o~,dkV
catch(Exception e){e.printStackTrace ();} 5C/W_H+9iK
A1:<-TF6^p
etj8M y6=
Utility.log(nFileLength); U7.3`qd"
<Brq7:n|
5YaTE<G
return nFileLength; ]S4kWq{Y
} V2cLwQ'0
v`MCV29!}
}s=D,_}m
//保存下载信息（文件指针位置） ]'=]=o~4
private void write_nPos() j`A%(()d
{ }<o.VY&;.
try{ m(E-?VMHo
output = new DataOutputStream(new FileOutputStream(tmpFile)); s_-G`xT>{
output.writeInt(nStartPos.length); 1+RG@Cp
for(int i=0;i<nStartPos.length;i++) |ul25/B B
{ 5BCXI8Ox9x
// output.writeLong(nPos); cj@Ygc)n
output.writeLong(fileSplitterFetch.nStartPos); *SQ hXTn
output.writeLong(fileSplitterFetch.nEndPos); Cfu]umZLn
} Oemi}
output.close(); 6Yebc_, R
} k/YEUC5
catch(IOException e){e.printStackTrace ();} r k;k:<c
catch(Exception e){e.printStackTrace ();} Vm6G5QwM
} 9(DS"fgC
a:Jsi=
W"+*%x
//读取保存的下载信息（文件指针位置） Mib(J+Il
private void read_nPos() [!p>Id
{ TaeN?jc5
try{ 5*u0VabC<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XRCiv
int nCount = input.readInt(); "l vPge
nStartPos = new long[nCount]; L5!aLv#
nEndPos = new long[nCount]; Y&KI/]ly,L
for(int i=0;i<nStartPos.length;i++) }YWLXxb;
{ 0Lmq?D
nStartPos = input.readLong(); "2q}G16K
nEndPos = input.readLong(); &{NN!X
} g-"@%ps
input.close(); x zu)``?
} VVO C-:
catch(IOException e){e.printStackTrace ();} P:vAU8d>
catch(Exception e){e.printStackTrace ();} {/G~HoY1i
} )WavG1
13wO6tS k
<QFT>#@T
private void processErrorCode(int nErrorCode) +<7~yZ[Z8
{ u)PB@
System.err.println("Error Code : " + nErrorCode); &^Q-:Kxs8
} >%5Ld`c:SD
awh<CmcZ
9HrT>{@
//停止文件下载 ;X,|I)
public void siteStop() /]m5HW(P7K
{ S0\QZ/je
bStop = true; U8qb2'a8
for(int i=0;i<nStartPos.length;i++) U;u@\E@2
fileSplitterFetch.splitterStop(); ~kPHf_B;z
]W39HL
$q,2VH:Ip
} -qaJ@T+J+7
} 5H#f;L\k
//负责部分文件的抓取 *Z\B9mx
**FileSplitterFetch.java }M-^A{C\%
*/ .1<QB{4~v
package NetFox; P}hHx<L
t=o2:p6&
&7_xr.c7
import java.io.*; / r6^]grg
import java.net.*; #&<>|m
<y[LdB/a
4\ R2\
public class FileSplitterFetch extends Thread { -l)vl<}
[AkL6
!m8MyZ}%
String sURL; //File URL 4H'\nsM
long nStartPos; //File Snippet Start Position x9Um4!/t
long nEndPos; //File Snippet End Position l#u$w&
int nThreadID; //Thread's ID xa#;<8 iV
boolean bDownOver = false; //Downing is over EYWRTh
boolean bStop = false; //Stop identical y,'M3GGl
FileAccessI fileAccessI = null; //File Access interface vYb.Ub+
D*.U?
0Cd)w4C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?e( y/
{ K",YAfJa
this.sURL = sURL; &iR3]FNI
this.nStartPos = nStart; :}(Aq;}X
this.nEndPos = nEnd; :_9MS0
nThreadID = id; 8h"Val|qP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U4;r.#qw,
} APY^A6^:j
QS(aA*D
;PM(q<@\
public void run() -Uj)6PzGu
{ ?5'EP|<
while(nStartPos < nEndPos && !bStop) lz1RAp0R"
{ "LZQ1P*ef$
Bv-|#sdxm
I!sh+e
try{ } )DE
URL url = new URL(sURL); UF37|+"E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b7-M'-Km0_
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;>hWAS
String sProperty = "bytes="+nStartPos+"-"; rywui10x*
httpConnection.setRequestProperty("RANGE",sProperty); pUbf]3 t
Utility.log(sProperty); L_4c~4
; '6`hZ
9~3;upWu!
InputStream input = httpConnection.getInputStream(); O_=2{k~s0
//logResponseHead(httpConnection); K9-;-{qb
/`6Y-8e2
u NmbR8Mx
byte[] b = new byte[1024]; Ub[SUeBGH
int nRead; 7\(mn$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hwb+@'o
{ aE aU_f/
nStartPos += fileAccessI.write(b,0,nRead); VZveNz@]r
//if(nThreadID == 1) zD}@QoB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X=C*PWa7
} ?XCFRt,ol
\e)>]C}h
gR5 EK$
Utility.log("Thread " + nThreadID + " is over!"); jGm`Qg{<
bDownOver = true; ky4;7RK
//nPos = fileAccessI.write (b,0,nRead); `G/%U~
} aMv?D(Meb
catch(Exception e){e.printStackTrace ();} 2fqg,_
} Q]h.{nN#PK
} 8M6 Xd]{%
M~/Pk7CC
b"4'*<=au
//打印回应的头信息 '%Fg+cZN\
public void logResponseHead(HttpURLConnection con) t+9[ki
{ FZFYwU\~.L
for(int i=1;;i++) QK~44;LVIJ
{ FS'|e?WU
String header=con.getHeaderFieldKey(i); 8-#_xsZ^;
if(header!=null) ov3FKMG?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PI G3kJ
Utility.log(header+" : "+con.getHeaderField(header)); g2RrBK,
else z6'Cz}%EP'
break; 3#\++h]QZ
} s+m3&(X
} Ga<Uvr%+
Ow"e3]}Mt
srbES6
public void splitterStop() hZZ
{ 5S9i>B
bStop = true; kh4., \'
} e:9s%|]T
fk*I}pDx
KIRCye
} H|\@[:A+
Fok%
1 b&<De
/* [,bra8f[C
**FileAccess.java ;OMR5KAz
*//文件访问(定位，写) @GVONluyU`
package NetFox; CE5A^,EsB
import java.io.*; UWXl c
02$d
)k^y<lC2a
public class FileAccessI implements Serializable{ A4~-{.w=
|l-~,eRvi5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8(zE^W,[8"
RandomAccessFile oSavedFile; zi^?9n),
long nPos; d6+$[4w
2RbK##`vC
WrHY'
public FileAccessI() throws IOException L*6R5i>
{ WEaG/)y
this("",0); 1fH2obI~X
} 8@ZZ[9kt
T)Y{>wT
oNEjlV*
public FileAccessI(String sName,long nPos) throws IOException <da-iY\5
{ u<['9U
oSavedFile = new RandomAccessFile(sName,"rw"); ""@kBY1C
this.nPos = nPos; \<aR^Sj.
oSavedFile.seek(nPos); <rihi:4K
} {Mpx33
~dBx<
%f?Z/Wn
public synchronized int write(byte[] b,int nStart,int nLen) 3<x1s2U
{ $2E&~W %
int n = -1; 9,?7mgZp
try{ unF=";9H
oSavedFile.write(b,nStart,nLen); bu8AOtY9E-
n = nLen; Z35(f0b
} 12VSzIm
catch(IOException e) S[;d\Z]~
{ }`pxs
e.printStackTrace (); oh0*bh
} /:;"rnvq
L9$`zc
[xdi.6%
return n; |}o6N5)
} cx~XG
~@\sN+VS
|SfCuV#g/<
} 7_Op(C4,nC
.3'U(U
#|"M
/* (zX75QSKV
**SiteInfoBean.java *!.anbo@?z
*/ 8|{d1dy
package NetFox; ri/CLq^D
dw>1Ut{"3
@~QI3)=s
public class SiteInfoBean { ?j;,:n
~f:"Q(f+
+>ld
private String sSiteURL; //Site's URL {%oxzdPc
private String sFilePath; //Saved File's Path DJZ$M
private String sFileName; //Saved File's Name sOO_J!bblP
private int nSplitter; //Count of Splited Downloading File Aw]kQ\P&
yNhRh>l
e-Zul.m
public SiteInfoBean() @R_ON"h
{//nSplitter的缺省值为5 .(7m[-iF!
//default value of nSplitter is 5 +a"f)4\
this("","","",5); *zwo="WA\t
} aH_0EBRc
+i~kqiy.
T0{X,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aHdQi,=z
{ h0?w V5H
sSiteURL= sURL; |=:<[FU
sFilePath = sPath; 9&bJ]
sFileName = sName; C~IE_E&Q`
this.nSplitter = nSpiltter; NM"5.
s6QD^[
P*]hXm85[K
} A">R-1R
P]O=K
&I:ZJuQ4
public String getSSiteURL() OtbPrF5
{ ^fQa whub
return sSiteURL; uD?Rs`
} F1t+D)KA>
)O2IEwPd.
#||D,[ _=+
public void setSSiteURL(String value) Jflm-Hhsf
{ J|w%n5Y
sSiteURL = value; +{#L,0t
} g2?yT ?
hEFOT]P4
26;Gt8
public String getSFilePath() {rwT4]4
{ F!fsW9
return sFilePath; BV6B:=E0
} $*:g~#bh
N@Q_5t0bk
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public void setSFilePath(String value) >Q=Q%~
{ P;eXUF+jn
sFilePath = value; B1A:}#
} T!I3.
+KaVvf
g4y&6!g
public String getSFileName() I_ AFHrj
{ (*_lLM@Cd
return sFileName; LJ K0WWch
} ,M~> t7+
_'4S1
}kF?9w
public void setSFileName(String value) k?rJGc G
{ ]:;dJc'
sFileName = value; \XO'7bNu-
} &;sW4jnt
~6K.5t7
R9(Yi<CC
public int getNSplitter() ^]D+H9Tl
{ Sx8C<S5r<
return nSplitter; MxH |yo[
} !b=W>5h
*^w}SE(
Ss0I{0
public void setNSplitter(int nCount) fv@<
{ /=T:W*C
nSplitter = nCount; 7xFZJ#
} lwz\"8
} a;v4R[lQ
F+ 7*SImv6
$fBj}\o
/* M~n./wyC
**Utility.java 1rS8+!9C
*/ $U7#3-'
package NetFox; nEPTTp+B
*U}ztH-+/
zkiwFEHA=
public class Utility { !??g:2
K9]zUe&#w
fZ&' _
public Utility() &8Z.m,s]
{ E*IP#:R
=ZO lE|4
]1pB7XL
} 1w,34*-}
AF8:bk,R
//线程睡眠 eco&!R[G
public static void sleep(int nSecond) >q0%yh-
{ IA{W-RRb
try{ 6B*#D.fd*
Thread.sleep(nSecond); Ndmw/ae
} T"aE]4_
catch(Exception e) mYj)![
{ u:f.;?
e.printStackTrace (); i]s%tEZ1
} Y%?*Lj|
} bdY:-8!3
nt+OaXe5D
//日志 (,tu7u{
public static void log(String sMsg) m=+x9gL2
{ 1;DRcVyS+
System.err.println(sMsg); V#b=mp
} @OGG]0 J
fUGappb
Zxhbnl6
public static void log(int sMsg) YaL:6[6
{ OScqf]H
System.err.println(sMsg); s2GF*{
} (KwC,0p
} =Xg/[J%
0:>hK\F#
X:I2wJDs\
/* jr_z ?
**TestMethod.java f0j]!g
*/ "*.N'J\
package NetFox; }r!+wp
t=xEUOQAn
qTN%9!0@9
public class TestMethod { 9(nq 4HvI
cs?WE9N
1_#;+S
public TestMethod() E1tCY.N{
{ ///xx/weblogic60b2_win.exe dq`{fqGl
try{ 8e3eQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K!.t}s.t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P tLWFO
SiteFileFetch fileFetch = new SiteFileFetch(bean); AFm9"mQrw
fileFetch.start(); Kvo&_:
} 1^2Q`~,g
catch(Exception e){e.printStackTrace ();} <nN.$4~X
5OtdB'UITd
oC*a;o
} #{{p4/:
u '/)l}
Nh_\{ &r
public static void main(String[] args) >*VvV/UU
{ ]wdE :k,D
new TestMethod(); y`j=(|DV
} zSQy
} } `r.fD
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