http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); gY)NPi}!`
} fT7Z6$
for(int i=0;i<nEndPos.length-1;i++) /^#8z(@B
{ #2N']VP
nEndPos = nStartPos[i+1]; iw`,\V&
} -!X,MDO
nEndPos[nEndPos.length-1] = nFileLength; <IiX_*
} C~C}b
} `5VEGSP]
mkJC*45
>U.)?>G/dt
//启动子线程 +9 Uo<6}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <r[5 S5y
for(int i=0;i<nStartPos.length;i++) nEtG(^N
{ wUnz D)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f:/[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I-@A{vvPK
nStartPos,nEndPos,i); UIhU[f]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3['aK|qk.
fileSplitterFetch.start(); ]Q?`|a+i
} V$D+Joj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^h q?E2-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g;N)K3\2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a4zq`n|3U
nEndPos = " + nFileLength); Zd2B4~V
// fileSplitterFetch[nPos.length-1].start(); D..dGh.MY
iL^bf*
f-w-K)y$ht
//等待子线程结束 ^jY'Hj.Bs
//int count = 0; i_ha^mq3
//是否结束while循环 6qCRM*V
boolean breakWhile = false; 3^ct;gz
Td7f
5PaOa8=2f
while(!bStop) Z*9Qeu-N:
{ \Lp|S:u
write_nPos(); pZpAb+
Utility.sleep(500); d&!;uzOx
breakWhile = true; o09)esy
{FIr|R&
#84<aM
for(int i=0;i<nStartPos.length;i++) TLBIM
{ L7~9u|7a#
if(!fileSplitterFetch.bDownOver) 17-D\ +}
{ hJkP_(+J\
breakWhile = false; byT@O:fL
break; .3yoDab
} b7]MpL
} nnv&~C
if(breakWhile) OKXELP
break; =jz*|e|V
T#HW{3
PWch9p0U
//count++; :A~6Gk92A
//if(count>4) x]e&G!|
// siteStop(); TSgfIE|
} )D_\~n/5
s{"}!y=]
B+8lp4V9%
System.err.println("文件下载结束！"); 'Gr}<B$A3
} 6~:eO(pK l
catch(Exception e){e.printStackTrace ();} dX720/R
} JO|%Vpco
m%=] j<A
4#dS.UfI
//获得文件长度 ZQY]c
public long getFileSize() T:~c{S4&
{ %%7~<=rk
int nFileLength = -1; | Ns-l (l
try{ ^ UB*Q
URL url = new URL(siteInfoBean.getSSiteURL()); Rxl )[\A*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u3[A~V|0=
httpConnection.setRequestProperty("User-Agent","NetFox"); h$[tEmD%
W/*2I3a
u,<#z0R|;$
int responseCode=httpConnection.getResponseCode(); /cn=8%!N
if(responseCode>=400) =nQ"ye
{ >)g`;iO
processErrorCode(responseCode); >T*/[{L8;
return -2; //-2 represent access is error .~#<>
} oqzx}?0
VgfA&?4[
:1Jg;G
String sHeader; d-%!.,F#W
R"Q=U}?$
BMlnzi
for(int i=1;;i++) 3QL I|VpO
{ R~40,$e{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -phwzR\(t
//Utility.log(in.readLine()); b!W!Vvf^x
sHeader=httpConnection.getHeaderFieldKey(i); HX1RA5O
if(sHeader!=null) `<I+(8]Uz
{ &A=>x
if(sHeader.equals("Content-Length")) S{cy|QD
{ x!CCSM;q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %E q}H
break; g~FA:R
} &WW|! 6
} <^j,jX
else H]@M00C
break; 8BnI0l=\
} _tE`W96J
} n(-1vN
catch(IOException e){e.printStackTrace ();} N}0-L$@SL
catch(Exception e){e.printStackTrace ();} D[) Z$+D4f
2/.Euf
f?O?2g
Utility.log(nFileLength); UR')) 1n
jOs&E^">&B
DyiyH%SSD
return nFileLength; c8qsp n
} cPcp@Dp
?3ldHWa
o#V}l^uU=
//保存下载信息（文件指针位置） Bob K>db
private void write_nPos() @y,pfWh`
{ 3DH} YAUU
try{ 7MXi_V;p<
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZTV|rzE
output.writeInt(nStartPos.length); }?zy*yL
for(int i=0;i<nStartPos.length;i++) a6AD`| U8
{ -LAYj:4
// output.writeLong(nPos); XW]'by
output.writeLong(fileSplitterFetch.nStartPos); VfS&V*un
output.writeLong(fileSplitterFetch.nEndPos); @ i$jyc
} @1_M's;
output.close(); HyKvDJ 3_
} pWY $aI
catch(IOException e){e.printStackTrace ();} ,Y|WSKY*
catch(Exception e){e.printStackTrace ();} wO6 D\#
} }Gmwm|`*
sTx23RJ9
L+s3@C;b
//读取保存的下载信息（文件指针位置） BeAkG_uG
private void read_nPos() 5>{S^i~!
{ G:'hT=8
try{ L4bx [
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SJ(<u2J]
int nCount = input.readInt(); 0[(TrIpXl
nStartPos = new long[nCount]; @edx]H1~^
nEndPos = new long[nCount]; EqW/Wxv7b
for(int i=0;i<nStartPos.length;i++) xY]Y
{ `acX1YWh5
nStartPos = input.readLong(); B(+J?0Dj
nEndPos = input.readLong(); ~\;s}Fv.
} pY75S5h:
input.close(); cB,O"-
} |Tn+Aq7
catch(IOException e){e.printStackTrace ();} /DxaKZ ;b
catch(Exception e){e.printStackTrace ();} _ISIq3A?
} .UJp#/EHs
QahM)Gb
QrmiQ]d*p
private void processErrorCode(int nErrorCode) AUZ^XiK
{ @3T)J,f
System.err.println("Error Code : " + nErrorCode); vwA d6Tm
} tGq0f"}'J
CKoRq|QG_
9 b?Nlk8d
//停止文件下载 9fLxp$`(T
public void siteStop() Qq,w6ekr
{ [nL{n bli
bStop = true; ~!bA<q
for(int i=0;i<nStartPos.length;i++) s/' ]* n
fileSplitterFetch.splitterStop(); rd#O ]
3<c_`BWu
M$@Donx
} =t,}I\_^c
} zh{:zT)(1
//负责部分文件的抓取 xA?(n!{P
**FileSplitterFetch.java ZT;8Wvo
*/ 2h:*lV^
package NetFox; mpcO-%a
aJAQ G
1?!z<<
import java.io.*; v'fX'/
import java.net.*; MlbQLtw
)I/K-zj
@nPXu2c?u7
public class FileSplitterFetch extends Thread { B<et&r;
$0(~ID
I=vGS
String sURL; //File URL 71)DLGL
long nStartPos; //File Snippet Start Position g`NJ `
long nEndPos; //File Snippet End Position Q^p>hda
int nThreadID; //Thread's ID i'6>_,\(
boolean bDownOver = false; //Downing is over }VetaO2*
boolean bStop = false; //Stop identical [pAW':
FileAccessI fileAccessI = null; //File Access interface |ORro r}
5:"zs
vv 7T/C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dE ,NG)MH
{ b~5Q|3P9
this.sURL = sURL; ke~S[bL%-
this.nStartPos = nStart; Oo-%;l`&
this.nEndPos = nEnd; &@&0n)VTd
nThreadID = id; TmH'_t.*T~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7BNu.5*y
} =~|:93]k
C VyYV &U,
*F_ dP
public void run() 3M@!?=|U
{ y?r:`n
while(nStartPos < nEndPos && !bStop) ug?])nO.C
{ \os iY^
mW+QJ`3
(hb\1wZ
try{ FxK2 1
URL url = new URL(sURL); mh5ozv$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6`V2-zv$
httpConnection.setRequestProperty("User-Agent","NetFox"); M~o\K'
String sProperty = "bytes="+nStartPos+"-"; +^@;J?O
httpConnection.setRequestProperty("RANGE",sProperty); OS.oknzZZ
Utility.log(sProperty); 3lW7auH4Y{
&OXnZT3P
(*XSrQ
InputStream input = httpConnection.getInputStream(); S1`;2mAf*
//logResponseHead(httpConnection); Wwf],Ya
{&qB!axj
9^AfT>b~f
byte[] b = new byte[1024]; vz^w%67&
int nRead; v})-:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 83|7#L
{ CSBk
nStartPos += fileAccessI.write(b,0,nRead); doj$chy
//if(nThreadID == 1) 5PCMxjon
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;OTd<
} O! t> @%)
kCuIEv@
.=u8`,sO
Utility.log("Thread " + nThreadID + " is over!"); ivi,/~L
bDownOver = true; o`EL)K{
//nPos = fileAccessI.write (b,0,nRead); "j]85
} iW\Q>~0#_
catch(Exception e){e.printStackTrace ();} FFvF4]|L
} ]-7$wVQ<
} /Ayo78Pi
XXe?@w2{
Hyj<Fqr!.
//打印回应的头信息 *w/})Y3^
public void logResponseHead(HttpURLConnection con) SZ*Nr=X
{ VD).UdUn
for(int i=1;;i++) !-OPzfHrI
{ $vQ#ah/k
String header=con.getHeaderFieldKey(i); ;n"Nv}<C
if(header!=null) "'8^OZR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q^_*&},V
Utility.log(header+" : "+con.getHeaderField(header)); N-~Uu6zr
else B>!OW2q0D
break; P*\h)F/3}t
} "PI]k
} |;[%ZE"
6')pM&`t
:hA=(iz
public void splitterStop() xKZLXQ'e-
{ IL\2?(&Z
bStop = true; ap7ZT7KW
} 9|}u"jJB%E
x_yQoae
Km=dId7]
} c[h{C!d1
Q`Z=}^
!MNnau%O
/* lebwGW,!
**FileAccess.java Pm Zb!|
*//文件访问(定位，写) n&j@7R
package NetFox; eMDO;q
import java.io.*; |IL/F]I
I1Jo8s
C(Bh<c0@
public class FileAccessI implements Serializable{ .*3.47O
f7mN,_Lt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vfn _Nq;
RandomAccessFile oSavedFile; )e1&[0
long nPos; tcm?qro)
,'KS:`m!
k/hD2tBLu
public FileAccessI() throws IOException q3CcXYY
{ 'DDlX3W-
this("",0); KTQy pv
} WaaF;|,(
fH#*r|~
{Y\W&Edw%
public FileAccessI(String sName,long nPos) throws IOException - s}
{ l[_y|W5
oSavedFile = new RandomAccessFile(sName,"rw"); K]
this.nPos = nPos; 3t*e|Ih&j5
oSavedFile.seek(nPos); a (mgz&*
} 2!7)7wlj0
Zs$Qo->F
qir/Sa'[
public synchronized int write(byte[] b,int nStart,int nLen) V\!6K
{ ;$\?o
int n = -1; }u>F}mUa
try{ %YH+=b:uW
oSavedFile.write(b,nStart,nLen); )37.H^7
n = nLen; whA
} f4h|Nn%;
catch(IOException e) Tx+Bkfj
{ -$; h+9BO
e.printStackTrace (); 3Y L
} qId-v =L
QO-R>
LhfI"fc
return n; 6rx%>\UkS
} s%{8$>8V.
`ZC{<eVJ}=
ib3u:
} w6PKr^
w[WyT`6h!
sp/l-a
/* e13{G@
**SiteInfoBean.java /^F_~.u{
*/ sy ]k
package NetFox; P$a `8~w
H(JgqbFB*
tfSY(cXg'T
public class SiteInfoBean { R.Plfm06Ue
iq25|{1$
7jj.maK
private String sSiteURL; //Site's URL }k`-n32)|
private String sFilePath; //Saved File's Path n%SR5+N"
private String sFileName; //Saved File's Name fku\O<1
private int nSplitter; //Count of Splited Downloading File wc&`/'<p
'V*ixK8R0
p}b:(QN~m
public SiteInfoBean() O!,WH?r
{//nSplitter的缺省值为5 \o&\r)FX
//default value of nSplitter is 5 SRUg2)d
this("","","",5); ?)Psf/
} k^JV37;bl
_7)>/YK?}4
S\,~6]^T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^AI5SjOUx
{ B8f BX!u/
sSiteURL= sURL; ^B>BA
sFilePath = sPath; :RxWHh3O
sFileName = sName; YqJ `eLu
this.nSplitter = nSpiltter; h()Ok9]
pG|+\k/B
v$P<:M M
} EJ%Kr$51K
kF1Tg KSd
ZFJqI
public String getSSiteURL() L"_l(<g
{ 3pV^Oe^9
return sSiteURL; o\#C#NiT
} jMpV c E#
>dr34=(
']x`d
public void setSSiteURL(String value) VssD
{ bzl-|+!yB
sSiteURL = value; {mkD{2)KQ
} <$V!y dO
"%mu~&Ga
w~3~:w$
public String getSFilePath() e hgUp =
{ bXx2]E227
return sFilePath; ,4OH9-Q1
} /qKO9M5A
oZ/z{`
:c_>(~
public void setSFilePath(String value) A#&,S4Wi|
{ )6t=Bel
sFilePath = value; " iz'x-wy
} 4U;Zs3
6AA"JX
;%wY fq~P
public String getSFileName() ~8j4IO(
{ .!B>pp(9
return sFileName; Y*KP1=Md
} ~vL`[JiK
/'ukeK+'
I?z*.yA*
public void setSFileName(String value) a%IJ8t+mn
{ W`d\A3v
sFileName = value; IHrG!owf
} Gy3t
;ATn&
HgY>M`U
public int getNSplitter() @ uF$m/g
{ ZDhl$m[m
return nSplitter; 4(hHp6}b
} _'.YC<;
egd%,`
`yvH0B -
public void setNSplitter(int nCount) 0o>l+c
{ zDD1EycH
nSplitter = nCount; @j{n V@|
} in[yrqFb7t
} mjI $z3
fPj*qi
NmH:/xU?^
/* xV}ybRKV
**Utility.java [3~mil3rO
*/ -!s?d5k")
package NetFox; ^]_5oFRIj
$.g)%#h:
kvoEnwBe_
public class Utility { PAcbC|y
p?#%G`dm
Z4ZR]eD
public Utility() -IP3I
{ $YPQi.
8K;wX%_,
D$vP&7pOr4
} 8A,="YIt
7k==?,LG3
//线程睡眠 .zMM!l3
public static void sleep(int nSecond) ;'fn{j6C
{ mKh<M)Bz
try{ nWzGb2Y
Thread.sleep(nSecond); M,WC+")Z=
} |Ox!tvyr
catch(Exception e) Rc.8j,]
{ =I6u*$9<
e.printStackTrace (); E{#Y=
} a=%QckR*
} L74Sx0nk=
g218%i
//日志 $At,D.mGkb
public static void log(String sMsg) |TE\]
{ rf:CB&u
System.err.println(sMsg); noLb
} ~p'DPg4
KJ]ejb$
h=`1sfz
public static void log(int sMsg) I8]q~Q<-P
{ y9@DlK
System.err.println(sMsg); HbUadPr
} ,VTX7vaH
} 1r-#QuV#
N:yyDeGyW
(8?5REz
/* (qky&}H
**TestMethod.java FhyA_U%/nF
*/ MY$-D+#/`
package NetFox; GSh~j-C'
G"'[dL)N>
b#2$Pd:(
public class TestMethod { ?xgrr7
cYafQyU
)b_ GKA `
public TestMethod() u3XQ<N{Gj
{ ///xx/weblogic60b2_win.exe ^^m3 11=
try{ G;CB%qXI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a!?&8$^<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;&9A Yh.
SiteFileFetch fileFetch = new SiteFileFetch(bean); C*f3PB=H_
fileFetch.start(); w&E*{{otJ
} ?V>\9?zb
catch(Exception e){e.printStackTrace ();} a!!>}e>Cj*
=yZiBJ
U $ bLt
} UJX=lh.o
YhzDi>hob
1D pRm(
public static void main(String[] args) t;~H6
{ ?[ts<Ltp
new TestMethod(); &d8z`amP
} @A-^~LoP.
} NIQX?|;b{
点击下载更多相关资料