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)); @uldD"MJ<]
} [ 'lu;1-,
for(int i=0;i<nEndPos.length-1;i++) ^'0N%`bY!
{ hlB\Xt
nEndPos = nStartPos[i+1]; yDwh]t
} WFh.oe8
nEndPos[nEndPos.length-1] = nFileLength; 6#!CBY^{
} $`55 E(
} ^9:`D@Z+
V5z2.} 'o-
9$HBKcO
//启动子线程 )c{>@WM~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3ie k>'T
for(int i=0;i<nStartPos.length;i++) RYjK4xT?Y/
{ PPr Pj^%z=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9K/EteS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2Y23!hw
nStartPos,nEndPos,i); [I3Nu8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5dI=;L>D
fileSplitterFetch.start(); J\Pb/9M/
} oDMPYkpTu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XhHgXVVGG<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vxj:Y'}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h_[{-WC
nEndPos = " + nFileLength); }!oEjcX'
// fileSplitterFetch[nPos.length-1].start(); !>n!Q*\(Ov
b4i=%]v8
XPO-u]<W
//等待子线程结束 6]Hwr_/tk
//int count = 0; 45sEhs[$
//是否结束while循环 TZ5TkE;1
boolean breakWhile = false; 94BH{9b5
={sjoMW
uR5+")r@S
while(!bStop) i[IFD]Xy!j
{ Lo{wTYt:J
write_nPos(); ou<3}g
Utility.sleep(500); XGR2L DR
breakWhile = true; t{jY@JT|
b>OB}Is
w\o6G7
for(int i=0;i<nStartPos.length;i++) = IRot
{ !6%?VJB|b
if(!fileSplitterFetch.bDownOver) *VsVCUCz5*
{ RI&O@?+U
breakWhile = false; P'lnS&yA
break; FL^ _)`
} -&>V.hi7
} 9 A ?{}c
if(breakWhile) =wdh#{
break; t.28IHJ
U 5J _Y
mG&A_/e!9
//count++; W3tin3__
//if(count>4) gHBvQ1g
// siteStop(); 1fS&KO{a
} :^3)[.m
;rT'~?q
cQj`W *
System.err.println("文件下载结束！"); I"88O4\@
} +9b{Y^^~T
catch(Exception e){e.printStackTrace ();} KHML!f=mu
} I.jqC2G
S@HC$
uI7n{4W*x
//获得文件长度 |NZi2Bu
public long getFileSize() v"o"W[
{ Wn(!6yid
int nFileLength = -1; U]sAYp^$
try{ SWV*w[X<X
URL url = new URL(siteInfoBean.getSSiteURL()); ~{/M_ =
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V2Vr7v=Y"
httpConnection.setRequestProperty("User-Agent","NetFox"); PlzM`g$A
^[xcfTN
q5SPyfE[
int responseCode=httpConnection.getResponseCode(); P[ :_"4U
if(responseCode>=400) OB(oOPH
{ 51q|-d
processErrorCode(responseCode); u]IbTJ'
return -2; //-2 represent access is error kWXLncE
} PR.3EL
,*XB11P
Q%JI-&K
String sHeader; ~Kw#^.$3T
~V8z%s@
#{q.s[g*+1
for(int i=1;;i++) d2`g,~d
{ @=Q!a (g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XGx[Ny_A2
//Utility.log(in.readLine()); o%t4WQ|bj
sHeader=httpConnection.getHeaderFieldKey(i); 5CFNBb%Xy
if(sHeader!=null) Qu61$!
{ VV$t*9w
if(sHeader.equals("Content-Length")) ,/{e%J
{ k."p&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \~ D(ww
break; -eG~
} %lHHTZ{+
} H{*Dc_
else :25LQf^nz
break; +lx&$mr?
} 2|je{
} FOXSs8"c]!
catch(IOException e){e.printStackTrace ();} 1#A$&'&\J;
catch(Exception e){e.printStackTrace ();} ' P?h?w^T
0kkDlWkzo
=8\.fp
Utility.log(nFileLength); ?R)]D:`
P1-eDHYw
bC<W7qf]}
return nFileLength; HT;^u"a~
} ]3_b3@k
,;`f* #
Y,}_LS$f
//保存下载信息（文件指针位置） Jl/wP
private void write_nPos() =fcg4h5(
{ KxkBP/`3Q
try{ b7QE
output = new DataOutputStream(new FileOutputStream(tmpFile)); Za:j;u Y
output.writeInt(nStartPos.length); gg/`{
for(int i=0;i<nStartPos.length;i++) cpQ5F;FI
{ h[mT4e3c
// output.writeLong(nPos); xLW$>;kI
output.writeLong(fileSplitterFetch.nStartPos); R/+$ :
output.writeLong(fileSplitterFetch.nEndPos); v-1}&K
} &xnQLz:#
output.close(); vF27+/2+R
} S+T/(-W
catch(IOException e){e.printStackTrace ();} h aAY=:
catch(Exception e){e.printStackTrace ();} ')"+ a^c
} |?!i},Ki;
&W2*'$j"_
N6Mr#A-{
//读取保存的下载信息（文件指针位置） IO\4dU)
private void read_nPos() W7S~~
{ FnO@\{M"A
try{ UkL1h7}a\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f<YYo
int nCount = input.readInt(); Q\$3l'W
nStartPos = new long[nCount]; <`}P
nEndPos = new long[nCount]; <3;p>4gN
for(int i=0;i<nStartPos.length;i++) n Nt28n@
{ ~non_pJ
nStartPos = input.readLong(); bKQho31a'
nEndPos = input.readLong(); M-o'`e'
} jxog8E
input.close(); |toP86
} yb`PMjj15
catch(IOException e){e.printStackTrace ();} y{ur'**l
catch(Exception e){e.printStackTrace ();} en<~_|J
} b,xZY1a
Xh9QfT,
zPby+BP
private void processErrorCode(int nErrorCode) =XP[3~
{ kBo:)Vej4
System.err.println("Error Code : " + nErrorCode); ?KC(WaGJQ
} x)PW4{3qR
\9?[|m z
[9; @1I<x
//停止文件下载 UqP{Cyy{
public void siteStop() ]\(8d[4
{ {&51@UX
bStop = true; /(dP)ysc
for(int i=0;i<nStartPos.length;i++) *1)>He$qL
fileSplitterFetch.splitterStop(); GJ ^c^`
./YR8#,
}HgG<.H>
} @>2pY_
} S_ATsG*(
//负责部分文件的抓取 I?e5h@uE
**FileSplitterFetch.java xRh 22z
*/ Tgdy;?
package NetFox; -k'<6op
G@8)3 @
y4^u&0}0$
import java.io.*; G3.aw
import java.net.*; xcB\Y:
vSgT36ZF
7Uenr9)M
public class FileSplitterFetch extends Thread { t<H"J__&
At Wv9
@*6fEG{,q
String sURL; //File URL \x<8
long nStartPos; //File Snippet Start Position *6Wiq5M>.
long nEndPos; //File Snippet End Position (V{/8%mWc
int nThreadID; //Thread's ID 8Y($ F2
boolean bDownOver = false; //Downing is over eADCT
boolean bStop = false; //Stop identical Ca2r<|uA
FileAccessI fileAccessI = null; //File Access interface LPvp (1
EZUaYp~M
tB_le>rhl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -&Rv=q>
{ *;<fh,wOk
this.sURL = sURL; qmrT dG
this.nStartPos = nStart; _#8hgwf>
this.nEndPos = nEnd; 3c<aI=$^
nThreadID = id; 78&|^sq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "5hk%T'
} U&^q#['
)jM%bUk,!
8!_jZf8
public void run() gQnr.
{ 3jx%]S^z|
while(nStartPos < nEndPos && !bStop) t~Q9}+
{ u?^V4 +V
oRV}Nz7hr
Rh="<'d
try{ e5L+NPeM6v
URL url = new URL(sURL); l<=;IMWd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 59E9K)c3
httpConnection.setRequestProperty("User-Agent","NetFox"); I7ao2aS
String sProperty = "bytes="+nStartPos+"-"; 1Bytu >2
httpConnection.setRequestProperty("RANGE",sProperty); A 6(`
Utility.log(sProperty); e" v%m'G
i5e10@Q{
o E+'@
InputStream input = httpConnection.getInputStream(); q<YM,%mgj
//logResponseHead(httpConnection); B%F]K<
L}Z.FqJ
*$Q>Om]
byte[] b = new byte[1024]; iq&3S0
int nRead; i<QDV W9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ptCF))Zm'
{ \:vF FK4a
nStartPos += fileAccessI.write(b,0,nRead); WogUILB
//if(nThreadID == 1) c{q+h V=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Fe~XO`
} k8gH#ENNK
&#p1ogf:
At7!Pas#@g
Utility.log("Thread " + nThreadID + " is over!"); omG2p
bDownOver = true; &Vlno*
//nPos = fileAccessI.write (b,0,nRead); eg[EFI.h
} (:oF\
catch(Exception e){e.printStackTrace ();} ^~4]"J};M
} N?\X2J1
} (Y1*Bs[l
<A3%182
ni;_Un~
//打印回应的头信息 ?ANWI8'_j
public void logResponseHead(HttpURLConnection con) ~f<']zXv
{ ~k*]Z8Z
for(int i=1;;i++) [ 8Ohg
{ /!6'K
String header=con.getHeaderFieldKey(i); 66=[6U9 *
if(header!=null) %4~"$kE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Jqoo&T")
Utility.log(header+" : "+con.getHeaderField(header)); Yh<F-WOo2
else )nm+_U
break; 4n,&,R r#
} K?.~}82c
} V)$!WPL@
C5~#lNC
a&s34Pd
public void splitterStop() !I7$e&Uz@
{ ff--y8h
bStop = true; iI GK"}
} Aztrq
F^dJ{<yX
2BccE
} WK%cbFq(
XYcZ;Z9:
g]~vZj
/* j0l,1=^>l
**FileAccess.java 1?'4%>kp
*//文件访问(定位，写) (UkP AE
package NetFox; pqG>|#RG
import java.io.*; x@#>l8k?
P\"kr?jZP
T?3Q<[SmI
public class FileAccessI implements Serializable{ J=A)]YE
[S6u:;7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fUw:jExz
RandomAccessFile oSavedFile; "Q:Gd6?h;
long nPos; x^s,<G
f;E#CjlTL
+d, ~h_7!
public FileAccessI() throws IOException ieyK$q
{ EX)&|2w
this("",0); -}7$;QK&a
} 7D'\z IW
{"o9pIh{~
*@rA7zPFf
public FileAccessI(String sName,long nPos) throws IOException ]d*9@+Iu
{ eMGJx"a
oSavedFile = new RandomAccessFile(sName,"rw"); I~7iIUD
this.nPos = nPos; 'FW?
oSavedFile.seek(nPos); f3UCELJ
} KhjC'CU,
@IG's-
!)a_@d.;i
public synchronized int write(byte[] b,int nStart,int nLen) )fJ"Hq
{ Du_5iuMh
int n = -1; ay8]"sa
try{ cAR `{%b
oSavedFile.write(b,nStart,nLen); k*1Lr\1
n = nLen; \M`qaFan5^
} xe@e#9N$
catch(IOException e) @eYpARF
{ lZk z\
e.printStackTrace (); CE"/&I
} .s{"NqRA
D||0c"E
LOUP
return n; BlJiHz!
} p4T$(]7
b0~r/M;J
'_v~+
} V%-hP~nyBx
V60L\?a
Q[OwP
/* .`D'eS6b
**SiteInfoBean.java ItVN,sVJb
*/ mSYjc)z
package NetFox; VMah3T!
%lCZ7z2o
H-_gd.VD
public class SiteInfoBean { !Fl'?Kz
g*$2qKm
12`u[O}\}-
private String sSiteURL; //Site's URL >axeUd+@i
private String sFilePath; //Saved File's Path 3Gs\Q{O:
private String sFileName; //Saved File's Name 3?o4
private int nSplitter; //Count of Splited Downloading File KVZB`c$<t
R3B+vLGX
qO{z{@jo55
public SiteInfoBean() ZthT('"a
{//nSplitter的缺省值为5 JBY.er`6C
//default value of nSplitter is 5 Nh\vWAz9
this("","","",5); 'rhgM/I
} Lu#qo^
yTZev|ej@
|))NjM'ZBl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lc!2'Do;
{ }nrjA0WN
sSiteURL= sURL; +&.zwniSS
sFilePath = sPath; PVb[E03
sFileName = sName; 0F[f%2j
this.nSplitter = nSpiltter; Cm[}DB
e:O,$R#g
e)sR$]i:v
} b 3x|Dq.
Xs2}n^#i
oSCaP,P
public String getSSiteURL() Sa g)}6+
{ W )FxN,
return sSiteURL; ~qinCIj
} 9c^,v_W@
#/>TuJc
um,f!ho-U
public void setSSiteURL(String value) j_JY[sex
{ Tpl]\L1v-
sSiteURL = value; ggDT5hb
} bRvGetX
@&\Y:aRO%i
K<P d.:
public String getSFilePath() QFP9"FM5F
{ f|{iW E2d
return sFilePath; 868X/lL
} s%:fZ7y
j[U#J
&g|[/~dIr
public void setSFilePath(String value) -[=~!Qr:
{ V'vWz`#
sFilePath = value; `'1g>Ebk0
} d]DV\*v
|5 V0_79
$toTMah w
public String getSFileName() zud_BOq{f
{ >9H^r\
return sFileName; NY7yk3
} ?i _ACKpw
sF{~7IB
%,\JTN|g|A
public void setSFileName(String value) J?o
{ qb? <u
sFileName = value; 2+9VDf2
} jR%*,IeB
gG?@_ie
7P1Pk?pxy
public int getNSplitter() 4)gG_k
{ x7S\-<8
return nSplitter; !Gmnck&+
} ~nA k-toJ
O},}-%G
ed6@o4D/kf
public void setNSplitter(int nCount) re*}a)iL
{ =Dn<DV
nSplitter = nCount; !Se0&Ob
} yCxYFi
} B0Df7jr%`>
LdZVXp^
SA TX_
/* ~P|;Y<?3
**Utility.java ?~o`mg
*/ #*g=F4>t
package NetFox; j4/[Z'5ny
s!IIvF
3-/|G-4k7
public class Utility { 0GUJc}fgvN
|Y uf/G%/
d"XZlEV
public Utility() t'U=K>7
{ C5~~$7k0
;FqmZjm
+[G9PP6
} qHk{5O3
zM0}(5$m
//线程睡眠 sT?{
public static void sleep(int nSecond) e"hfeNphz
{ Uj5-x%~
try{ h4]^~stI
Thread.sleep(nSecond); gWr7^u&q@|
} 'WW:'[Syn'
catch(Exception e) @} Ig*@
{ cQEUHhRg!
e.printStackTrace (); Qj^Uz+b
} CV0id&Nv
} Lap?L/NS
L"b&O<No
//日志 Bt<)1_
public static void log(String sMsg) S)U*1t7[
{ kp*v:*
System.err.println(sMsg); I# tlaz#
} CzBYH
;+~5XLk
.`IhxE~mN
public static void log(int sMsg) Em!- W5*s
{ E&8Nh J
System.err.println(sMsg); )Q=u[ p
} _*AI1/>`
} %Xh}{o$G
{4S UGo>
&@lfr623
/* e* [wF}))
**TestMethod.java w-Ph-L/
*/ xeF>"6\
package NetFox; _}5vO$kdO
$9YQ aN%
Pxl,"
public class TestMethod { :'T+`(
QATRrIj{e
Bc8&-eZ,
public TestMethod() J.UNw8z
{ ///xx/weblogic60b2_win.exe {]\7 M|9\
try{ naR<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !Q>xVlPVu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); { {\oC$
SiteFileFetch fileFetch = new SiteFileFetch(bean); $UzSPhv[
fileFetch.start(); EGl<oxL*R2
} A}lxJ5h0
catch(Exception e){e.printStackTrace ();} %mQ&pk
as@8L|i*
qxI$F
} Ae7FtJO
:of([e|u6
H8YwMhE7
public static void main(String[] args) DZqG7p$u4i
{ Sn[xI9}O
new TestMethod(); 6) i-S<(
} K9@.l~n
} 0h1u W26^
点击下载更多相关资料