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)); t1o 6;rK
} Z:7eroZP
for(int i=0;i<nEndPos.length-1;i++) B+U:=591
{ WEe7\bWF
nEndPos = nStartPos[i+1]; 4F G0'J&hw
} o.A:29KoU
nEndPos[nEndPos.length-1] = nFileLength; SU4i'o
} ]#^v754X^T
} K&`1{,
6V]m0{:E
m<-!~ ew
//启动子线程 4jC)"tch
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )]FXUz|;
for(int i=0;i<nStartPos.length;i++) &`v?oN9$
{ UAhWJ$(C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kl.;E{PL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;]Q6K9.d8
nStartPos,nEndPos,i); bV&9>fC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bA#9'Qu^j
fileSplitterFetch.start(); 3MNM<Ih
} "W%YsN0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A| A#|D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wV==sV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C&H'?0Y@
nEndPos = " + nFileLength); Fy Ih\
// fileSplitterFetch[nPos.length-1].start(); wCNn/%C
5kTs7zJ^
Y06^M?}
//等待子线程结束 {@)ZXg
//int count = 0; 4 O8ct,Y
//是否结束while循环 $$NWN?H~
boolean breakWhile = false; ~>u|7M$(
7GsKD=bl]
~W8Xg)
while(!bStop) Uc {m##!
{ 8R3{YJ6@T
write_nPos(); xt?-X%oY8
Utility.sleep(500); .6C/,rQ?c
breakWhile = true; 3;BIwb_
=;uMrb4
N~8H\
for(int i=0;i<nStartPos.length;i++) }-Mg&~e`
{ h>\C2Q
if(!fileSplitterFetch.bDownOver) P\ke%Jdpw?
{ /ki-Tha
breakWhile = false; pvyEs|f=%
break; oc( '!c
} WSH[*jMA
} FefroaJ:u
if(breakWhile) n>q!m@ }<
break; %T]^,y$n
K9k!P8Rd
Q*>)W{H&)
//count++; x5Lbe5/P
//if(count>4) *7h~0%WR
// siteStop(); b+|Jw\k
} @}d;-m~
6(`N!]e*L
M.mn9kw`
System.err.println("文件下载结束！"); YJ6~P
} W34xrm
catch(Exception e){e.printStackTrace ();} F1@Po1VTD
} kx;X:I(5&P
3?*dv14
2 3PRb<q
//获得文件长度 -|m3=#
public long getFileSize() JK =A=
{ IHO*%3mA/
int nFileLength = -1; bLai@mL&a
try{ e`qrafa
URL url = new URL(siteInfoBean.getSSiteURL()); V'XEz;Ze
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qi`3$<W>
httpConnection.setRequestProperty("User-Agent","NetFox"); Yn~fnI{
c{/R?<
eW(pP>@k,
int responseCode=httpConnection.getResponseCode(); 5 qfvHQ ~M
if(responseCode>=400) imYfRi=$
{ H<_Tn$<zH.
processErrorCode(responseCode); 3s!6rT_=)d
return -2; //-2 represent access is error ^~[7])}g6
} bu _ @>`S
E#,"C`&*
s0?'mC+p
String sHeader; Qt+D ,X
larv6ncV
Dz~0(
for(int i=1;;i++) -pYmM d,
{ Ea@0>_U|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _ Lh0
//Utility.log(in.readLine()); _C/|<Ot:
sHeader=httpConnection.getHeaderFieldKey(i); M?h{'$T
if(sHeader!=null) G7 UUx+X
{ ['}|#3*w
if(sHeader.equals("Content-Length")) ML12&E>
{ |KYl'"5\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kzZgNv#G;
break; :.+w'SEn4M
} {:gx*4}q8
} HqWWWCWal
else Zmyq6.1q~
break; kS-BB[T
} I_ZJnu<
} :b44LXKCP
catch(IOException e){e.printStackTrace ();} l[T-Ak
catch(Exception e){e.printStackTrace ();} )4ek!G]Rb
J -z.
,H7_eVLWR
Utility.log(nFileLength); ^@V*:n^
1$T`j2s
!.j{vvQ/
return nFileLength; Qf=^CQ=lV
} $vXY"-k
|D)CAQn,
$\P/ %eP
//保存下载信息（文件指针位置） %HG+|)b
private void write_nPos() ,"`20.Lv
{ ED>7
try{ 5<(* +mP`
output = new DataOutputStream(new FileOutputStream(tmpFile)); w PR Ns9^
output.writeInt(nStartPos.length); LLTr+@lj
for(int i=0;i<nStartPos.length;i++) QPf\lN/$4d
{ _;PQt" ]
// output.writeLong(nPos); W8g13oAu"
output.writeLong(fileSplitterFetch.nStartPos); }'P|A
output.writeLong(fileSplitterFetch.nEndPos); uBww
} 4~Cf_`X}]
output.close(); Jq` Dvz
} Gky*EY
catch(IOException e){e.printStackTrace ();} m-O*t$6
catch(Exception e){e.printStackTrace ();} ,h^6y
} :(~<BiqR(
nN{DO:_o
RkG?R3e
//读取保存的下载信息（文件指针位置） P}Ig6^[m\
private void read_nPos() w]gLd
{ %DiQTg7V,
try{ i 7]o[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EcHZmf
int nCount = input.readInt(); 4xW~@meNB
nStartPos = new long[nCount]; 2`]c&k;]
nEndPos = new long[nCount]; %.$!VTO"
for(int i=0;i<nStartPos.length;i++) uY~mi9E
{ /9ORVV
nStartPos = input.readLong(); IMD^(k 2
nEndPos = input.readLong(); ]&]G
} 961&rR}d
input.close(); zRjbEL
} oqwW
catch(IOException e){e.printStackTrace ();} !6|_`l>G,
catch(Exception e){e.printStackTrace ();} j4i$2ZT'
} OG<*&V
DL,R~
$HQ~I?r{Hf
private void processErrorCode(int nErrorCode) Q I";[
{ wBpt W2jA
System.err.println("Error Code : " + nErrorCode); ia\Gmh
} %t&Lq}e
h{mzYy}b
H,KH}25
//停止文件下载 rmw}Ui"
public void siteStop() 2Di~}*9&
{ bsu?Q'q
bStop = true; eFs5l
for(int i=0;i<nStartPos.length;i++) |5;,]lbt
fileSplitterFetch.splitterStop(); &G%AQpDW5
65zwi-
^iEf"r
} |h $Gs2
} *=@8t^fa86
//负责部分文件的抓取 l atm_\
**FileSplitterFetch.java $Z&6
*/ %t_'rv
package NetFox; G:b6Wf
x%X3FbF]
&H# l*
import java.io.*; ~W>{Dd(J_
import java.net.*; ~*EipxhstJ
a)2l9
D7pQWlN\
public class FileSplitterFetch extends Thread { Y_*KAr'{P
@GAj%MK$
;L87 %P(.
String sURL; //File URL s8(Z&pQ
long nStartPos; //File Snippet Start Position <6]Hj2
long nEndPos; //File Snippet End Position \KJTR0EB:>
int nThreadID; //Thread's ID 6p;Pf9 f
boolean bDownOver = false; //Downing is over 0*:n<T9
boolean bStop = false; //Stop identical h(q4 B~
FileAccessI fileAccessI = null; //File Access interface lg-`zV3
(1S9+H>g
=4q5KI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;t7F%cDA
{ WuVsW3@
this.sURL = sURL; v0WB.`rO
this.nStartPos = nStart; u@D5SkT
this.nEndPos = nEnd; X ([^i;mr
nThreadID = id; \t{4pobo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <EyJ $$
} d.ywH;
@~{TL
f4<~_ZGr
public void run() O^c?w8
{ ;xTMOuI*
while(nStartPos < nEndPos && !bStop) 1;./e&%%
{ 5D3&E_S
:fX61S6)
ce4rhtkV
try{ q@1A2L\Om
URL url = new URL(sURL); .))k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M97+YMY)
httpConnection.setRequestProperty("User-Agent","NetFox"); 49/2E@G4.
String sProperty = "bytes="+nStartPos+"-"; aEQrBs
httpConnection.setRequestProperty("RANGE",sProperty); dG3?(}p+
Utility.log(sProperty); w2 (}pz:
unYPvrd
oVuIHb0w
InputStream input = httpConnection.getInputStream(); U#Kw+slM
//logResponseHead(httpConnection); cJT_Qfxx
%\v
4myikeUR_
byte[] b = new byte[1024]; 5Q}HLjG8Z
int nRead; !bK;/)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )jI4]6
{ .h w(;
nStartPos += fileAccessI.write(b,0,nRead); QncjSaEE
//if(nThreadID == 1) S% ptG$Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y,n8co^
} *s1o?'e
U2_;
=*4^Dtp
Utility.log("Thread " + nThreadID + " is over!"); |L;Hd.l7^*
bDownOver = true; fiAj#mX
//nPos = fileAccessI.write (b,0,nRead); K~&3etQF
} BR6HD7G
catch(Exception e){e.printStackTrace ();} WVyq$p/V
} ?fU{?nI}>p
} bMqS:+
|Qpo[E}a
;(g"=9e
//打印回应的头信息 oPAc6ObOV~
public void logResponseHead(HttpURLConnection con) 5U_ar
{ `ER#S_}
for(int i=1;;i++) kyB>]2
{ kad$Fp39
String header=con.getHeaderFieldKey(i); "H=fWz5z
if(header!=null) VF-[O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ojWf]$^y}
Utility.log(header+" : "+con.getHeaderField(header)); ^*NOG\BK@
else A?ESjMy(R
break; ^SUo-N''
} IOrYm
} iee`Yg!EOH
0,LUi*10
8r.MODZG/
public void splitterStop() w@N)Pu
{ F0'o!A#|(
bStop = true; sGMnm
} gcM(K.n
kvN6K6
|[bQJ<v6
} Df$Yn
z_&T>ME
C5^N)-]"
/* Mm^6*L]
**FileAccess.java 1kc{`oL
*//文件访问(定位，写) n u>6UjV
package NetFox; K!88 Nox(
import java.io.*; WdrMp
B8-Y)u1G
|R Qa.^.
public class FileAccessI implements Serializable{ \cAifU
7sJGB^vM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n{F&GE="
RandomAccessFile oSavedFile; 4,6?sTuX
long nPos; F.R0c@&W
aOW~! f/M
\?k"AtL
public FileAccessI() throws IOException tUFXx\p
{ "FfP&lF/
this("",0); o, qBMo^.
} P$A'WEO'
ubi6=
Gc!&I+kd
public FileAccessI(String sName,long nPos) throws IOException '^t(=02J
{ 2f0_Xw_V_
oSavedFile = new RandomAccessFile(sName,"rw"); "8yDqm
this.nPos = nPos; k*T&>$k}^
oSavedFile.seek(nPos); QTI^?@+N>
} Z5>}
!:dhK
y=WCR*N
public synchronized int write(byte[] b,int nStart,int nLen) qB=%8$J
{ NEMC
int n = -1; W QyMM@#
try{ }Mh`j$
oSavedFile.write(b,nStart,nLen); *7/MeE6)i
n = nLen; A `=.F
} {$-\)K
catch(IOException e) _k5-Wd5Ypw
{ }D#[yE,=\
e.printStackTrace (); q}7(w$&
} fL R.2vJ
Bdf]?s[]
o,y{fv:ki
return n; /\uW[mt
} |Q~5TL>b
6?jSe<4x
W#[3a4%m
} Q92hI"
=Cr F(wVO"
wo!;Bxo N
/* ehYGw2
**SiteInfoBean.java []eZO_o6j
*/ _;5N@2?
package NetFox; r)t-_p37
'ZQR@~G
QW"BGg~6c
public class SiteInfoBean { 0\^K\J,.
?9AtFT
ig,v6lqhM
private String sSiteURL; //Site's URL $t$YdleIH
private String sFilePath; //Saved File's Path bG9$&,
private String sFileName; //Saved File's Name B6a
private int nSplitter; //Count of Splited Downloading File |zSoA=7?
cY\"{o"C
n<>/X_m
public SiteInfoBean() AVv8Hhd
{//nSplitter的缺省值为5 0Fm,F&12
//default value of nSplitter is 5 3P2L phW
this("","","",5); ;F'/[l{+
} ;*EPAC+
lvZ:Aw r
Ni 5Su
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O_wRI\!
{ ZnYoh/
sSiteURL= sURL; ;;l-E>X0
sFilePath = sPath; |yow(2(F@
sFileName = sName; 0xg6
this.nSplitter = nSpiltter; e!~x-P5M`
}fKpih
27KfT]=
} %]i("21
u9%)_Q!14
JdeGQ
public String getSSiteURL() %7bZnK`C
{ LK[%}2me
return sSiteURL; X>y6-%@
} b}#ay2AR
u0& dDZ
)Dq/fW
public void setSSiteURL(String value) :.M"M$MRp8
{ @z)_m!yV1
sSiteURL = value; ${%*O}$
} ~'l.g^p bv
(Q09$
FO5'<G-
public String getSFilePath() !EQMTF=(
{ v(tr:[V
return sFilePath; h .$3jNU
} C6C7*ks
$VCWc#
$w$4RQk3n
public void setSFilePath(String value) 7EAkY`Op
{ [8QE}TFic
sFilePath = value; pP6pn~}
} W=T}hA#`
_:tisr{
\;G97o
public String getSFileName() &N!;d E
{ [!E8C9Q#!
return sFileName; LMvsYc~]q
} yXx}'=&!0
Qm\VZ<6/5
i`1QR@11
public void setSFileName(String value) <2a7>\74E0
{ Vi~F Q
sFileName = value; Y"&c .
} c*g(R.!
!Z6GID})p
3[L)q2;}$N
public int getNSplitter() jpCQ2XD:
{ .Lk2S "+
return nSplitter; @9pk-BB^D
} wb }W;C@
x-_!I>l&
kOGpe'bV
public void setNSplitter(int nCount) _YH)E^If
{ huau(s0um
nSplitter = nCount; ^r<bi%@C$
} rtz%(4aS
} X192Lar
=kspHP<k
ega< {t
/* :hp=>^$Y
**Utility.java /L1qdkG
*/ m"!!)
package NetFox; v?\bvg\E
@Ooh}V#J
&zF1&J58z
public class Utility { 7 C5m#e3
~pqp`
PQ2u R
public Utility() *HwTq[y
{ ;q&>cnLDR
TY,w3E_
(,E.1j]ji
} LV&tu7c
^6~CA
//线程睡眠 Xa2QtJq
public static void sleep(int nSecond) (l.`g@(L
{ `bGAc&,&
try{ zX!zG<<K
Thread.sleep(nSecond); A}b<Lg
} otXB:a
catch(Exception e) XY5I5H_U
{ J0}OmNTzD
e.printStackTrace (); RkN a;j)t
} R0M(e@H~
} mB$r>G/'
.! LOhZ
//日志 TZq']Z)#
public static void log(String sMsg) '(kySf[
{ 6M"]p
System.err.println(sMsg); 6|05-x|
} $H/3t?6h`
"~4ULl<i'
&Q^M[X
public static void log(int sMsg) tLpDIA_8
{ 4 ~17s`+
System.err.println(sMsg); E#_TX3B
} )#r]x1[Kn
} GCx]VN3&
()vxTTa
v!ULErs
/* gJ>?<F;
**TestMethod.java O1@xF9<
*/ DY6wp@A
package NetFox; KX9+*YY,
">kfX1LT
X;T(?,,
public class TestMethod { :JqH.Sqk
,|b<as@X
lhx6+w
public TestMethod() +"a .,-f!
{ ///xx/weblogic60b2_win.exe ~)}npS;
try{ D:llGdU#2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @R?S-*o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OFCOMM
SiteFileFetch fileFetch = new SiteFileFetch(bean); `,&h!h((
fileFetch.start(); fw_V'l#\
} `ejE)VL=8h
catch(Exception e){e.printStackTrace ();} 2_0OSbFv'P
UGEC_
q]tPsX5{*
} J;+iW*E:
Xi5ZQo!t
r}9qK%C G.
public static void main(String[] args) 0vUX^<
{ &?*M+q34
new TestMethod(); AFl]w'=
} jR\T\r4
} k:<yy^g$X
点击下载更多相关资料