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)); :Nofp&
} phM>.y_
for(int i=0;i<nEndPos.length-1;i++) |*}4 m'c
{ BD(Z5+EU1
nEndPos = nStartPos[i+1]; L4!{h|
} B95B|tU>.
nEndPos[nEndPos.length-1] = nFileLength; /!c${W!sY
} j4qJ.i
} `@nl
IiG6<|d8H
"'D=,*
//启动子线程 T}8Y6N<\m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z11O F
for(int i=0;i<nStartPos.length;i++) h5(4*$%
{ Hy^N!rBxfO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rzt Ru
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZIQ [bE7
nStartPos,nEndPos,i); hEp(A8g)bQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j KoG7HH
fileSplitterFetch.start(); +0OLc2 )w
} ZpnxecJUJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MdvcnaCG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9jw\s P@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V,cBk
nEndPos = " + nFileLength); +F^^c2E
// fileSplitterFetch[nPos.length-1].start(); \--8lH -K
3.*8)NW
))"6ern
//等待子线程结束 [n:<8ho
//int count = 0; }hhGu\
//是否结束while循环 Y\No4w ^|d
boolean breakWhile = false; , GP?amh
k7T`bYv
neLAEHV
while(!bStop) >U[j]V]
{ %^ !,t:d
write_nPos(); JU)dr4S?
Utility.sleep(500); v_DedVhe
breakWhile = true; 5yP\I+Fm
)v.=jup[
MB]<Dyj,
for(int i=0;i<nStartPos.length;i++) 8|\8O@
{ a6uJYhS~
if(!fileSplitterFetch.bDownOver) |>dI/_'
{ =w{Z@S(ukz
breakWhile = false; ?`PvL!'
break; lE4HM$p
} _sTROd)Vh
} )8$=C#qC[
if(breakWhile) ^G}47(
break; tM'P m
=Jyu4j *}
iMDM1}b
//count++; ~kEI4}O
//if(count>4) }khV'6"'|
// siteStop(); ~v|>xqWV
} `u&Rsz&^
@U& QI*
#Up86(Z
System.err.println("文件下载结束！"); q1d}{DU
} 9,:l8
catch(Exception e){e.printStackTrace ();} -C(crn
} v0H@Eg_
SC)g^E#
dtRwTUMe?
//获得文件长度 paCV!tP
public long getFileSize() %z,mB$LY
{ rWR}Stc@]
int nFileLength = -1; 7%x[q}
try{ ',JinE95
URL url = new URL(siteInfoBean.getSSiteURL()); ~d|A!S`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m8d!< h
httpConnection.setRequestProperty("User-Agent","NetFox"); Bf~vA4
i#vYyVr[
gc-@"wI?
int responseCode=httpConnection.getResponseCode(); G}b]w~ML~
if(responseCode>=400) #Y a4ps_
{ ix)M`F%P3
processErrorCode(responseCode); RC7]'4o
return -2; //-2 represent access is error 4NheWM6
} UCB/=k^m
L.*M&Ry
gG(fQ 89U"
String sHeader; [\v}Ul
s %j_H
-g*4(w
for(int i=1;;i++) 1mOh{:1u
{ Y)*#)f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EyJJ0
//Utility.log(in.readLine()); (X\@t-8
sHeader=httpConnection.getHeaderFieldKey(i); JfLqtXF[&"
if(sHeader!=null) A$Hfr8w1u
{ R{<kW9!
if(sHeader.equals("Content-Length")) Q ayPo]O
{ jaII r06
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v3~?;f,l
break; _=F=`xu
} }ppN k:B
} <Tzrj1"Q3
else D9^h; 8
break; n|Q@UPb/=
} 'YmIKIw
} g?goZPZB
catch(IOException e){e.printStackTrace ();} cQy2"vtU
catch(Exception e){e.printStackTrace ();} s>7}zU]
S9]'?|
m Bu
Utility.log(nFileLength); nP$Ky1y G
v_+{'F
@E7DyU|
return nFileLength; Z'`<5A%;
} 0l)~i''
n'n/Tu
;K:zmH
//保存下载信息（文件指针位置） bzBEX mC
private void write_nPos() 4&<oFW\r
{ i[7\[
try{ ^}/PGG\~r
output = new DataOutputStream(new FileOutputStream(tmpFile)); le|~BG hL
output.writeInt(nStartPos.length); 89pEfl j2
for(int i=0;i<nStartPos.length;i++) %g{X?
{ h7G"G"
// output.writeLong(nPos); V_:1EBzz
output.writeLong(fileSplitterFetch.nStartPos); 4;e5H_}Oo
output.writeLong(fileSplitterFetch.nEndPos); p& y<I6a,
} AYqX|
output.close(); ;DqWh0
} !;q&NHco
catch(IOException e){e.printStackTrace ();} _{I3i:f9X8
catch(Exception e){e.printStackTrace ();} +"\sc;6m.
} P+@/O
0L2F[TN
DR5\45v
//读取保存的下载信息（文件指针位置） 36}?dRw#p
private void read_nPos() o4G?nvK-
{ CGW.I$u
try{ T*Y~\~Jhu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oK6tTK
int nCount = input.readInt(); ?GKb7Oj
nStartPos = new long[nCount]; >)fi^
nEndPos = new long[nCount]; q/4J.jL
for(int i=0;i<nStartPos.length;i++) 9UdM`v)(
{ rK'L6o
nStartPos = input.readLong(); EH+"~-v)ae
nEndPos = input.readLong(); gX@HO|.t
} >?2M }TV3
input.close(); h5*JkRm
} ysQ_[ ]/
catch(IOException e){e.printStackTrace ();} RIWxs Zt
catch(Exception e){e.printStackTrace ();} ugdQAg
} eBZXI)pPh
.F98G/s
TV)h`\|Z*
private void processErrorCode(int nErrorCode) M'7fO3&|
{ M8MRoA6F
System.err.println("Error Code : " + nErrorCode); SE@LYeC}dE
} &47i"%
/?uPEKr
1F5XvQl
//停止文件下载 cM(:xv
public void siteStop() OcR$zlgs[v
{ CpUkCgg
bStop = true; [\^n=
for(int i=0;i<nStartPos.length;i++) h]IxXP?h[
fileSplitterFetch.splitterStop(); 1OGx>J6
|s7s6k)mm
t6bV?nc
} 1{)5<!9!l
} ~^NtO
//负责部分文件的抓取 .5^cb%B*
**FileSplitterFetch.java Zi*2nv'
*/ y;35WtDVb
package NetFox; x,=&JtKVc
so,t
F&!6jv
import java.io.*; ~8q)^vm>f?
import java.net.*; :}He\V
!a{^=#qq&I
m~iXl,r
public class FileSplitterFetch extends Thread { zU5v /'h>d
\\iQEy<i
]FJjgu<
String sURL; //File URL R3 -n>V5o
long nStartPos; //File Snippet Start Position C8J[Up
long nEndPos; //File Snippet End Position iw3FA4{(
int nThreadID; //Thread's ID Yz<3JRw
boolean bDownOver = false; //Downing is over &Qf/>@ l}
boolean bStop = false; //Stop identical B{QBzx1L9c
FileAccessI fileAccessI = null; //File Access interface %^?fMeI|Y
5dx$HE&b)
E(*0jAvO[z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &y\prip
{ 5#HW2"7
this.sURL = sURL; tIWmp30S
this.nStartPos = nStart; 0\X\izQ5
this.nEndPos = nEnd; )1]ZtU
nThreadID = id; %v=*Wb\3|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bBiE
} j_qbAP
R|6Cv3:
w;%.2VJ
public void run() / kF)
{ /MIe(,>Uh
while(nStartPos < nEndPos && !bStop) ,kyJAju>
{ g{7.r-uu
}fp-pe69z
FI)17i$
try{ T.])diuvj-
URL url = new URL(sURL); pd:WEI ,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R"-mKT}
httpConnection.setRequestProperty("User-Agent","NetFox"); r)Ma3FL0;
String sProperty = "bytes="+nStartPos+"-"; |-fgj'
httpConnection.setRequestProperty("RANGE",sProperty); /fKx}}g)
Utility.log(sProperty); 5[8xV%>;
Lz |?ek7Q
1XrO~W\=
InputStream input = httpConnection.getInputStream(); e2AX0(
//logResponseHead(httpConnection); 5Y.)("1f}f
4R#chQ
5GI,o|[s6
byte[] b = new byte[1024]; D@,6M#SK
int nRead; BnX0G1|#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S4Pxc ]!
{ (9tX5$e6N
nStartPos += fileAccessI.write(b,0,nRead); EGGWrl}1
//if(nThreadID == 1) ~IY%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j5(Z_dm'
} {dhXIs
_:ReN_0
z{8bvuE
Utility.log("Thread " + nThreadID + " is over!"); KWq+PeB5TS
bDownOver = true; B?OFe'*
//nPos = fileAccessI.write (b,0,nRead); o8 IL$:
} WO7z
catch(Exception e){e.printStackTrace ();} )!3V/`I
} M-$%Rzl_
} lXx=But
#QS`_TlKk
Q1T$k$n
//打印回应的头信息 IDad9 Bx
public void logResponseHead(HttpURLConnection con) ]vz%iv_
{ a1g,@0s
for(int i=1;;i++) gI&#o@Pm
{ e+=y*OmQ
String header=con.getHeaderFieldKey(i); ,L|%"K]yM
if(header!=null) fnpYT:%fG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y@NNrGDkT*
Utility.log(header+" : "+con.getHeaderField(header)); \e:7)R2<!x
else wVvF^VHV^
break; %h hfU6[
} O;+ maY^l
} NyaQI<5D
>Ifr [
I:E`PZ
public void splitterStop() MH =%-S
{ FDv<\2+ c
bStop = true; X1:V<,}"
} 5u,{6
O+nEXS\rQ
<!&[4-;fU
} HNb/-e ,"
S%$ }(
^8]NxV@l
/* )~&CvJ
**FileAccess.java aacpM[{f
*//文件访问(定位，写) n|6Ic,:[
package NetFox; aR[JD2G
import java.io.*; uY{|szC^2
PoHg,n]
_Ym]Mj' ln
public class FileAccessI implements Serializable{ zZ:>do\2
bpOYHc6,*`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'g">LQ~a+
RandomAccessFile oSavedFile; %7QV&[4!
long nPos; }cM}Oavh
V~UN
"0$a)4]
public FileAccessI() throws IOException FK^p")i
{ T5|qRlW
this("",0); biLs+\C
} Z EQ@IS:Y
W1WYej"
4%{,] q\p
public FileAccessI(String sName,long nPos) throws IOException zp6C3RG(
{ af6M,{F
oSavedFile = new RandomAccessFile(sName,"rw"); |e=,oV"
this.nPos = nPos; ay4 %
oSavedFile.seek(nPos); #./fY;:cj
} x" 7H5<
?(xnSW@r
LY+@o<>
public synchronized int write(byte[] b,int nStart,int nLen) BfXgh'Z~
{ K> %Tq
int n = -1; CVDV)#JA
try{ 36.Z0Z1'F>
oSavedFile.write(b,nStart,nLen); ke!?BZx
n = nLen; 'Oxy$U
} oph}5Krd)
catch(IOException e) ;^+\K-O]c
{ .7^c@i[
e.printStackTrace (); .4S.>~^7
} ]z;P9B3@&
=WyDp97@+
%Wg'i!?cB
return n; C:GK,?!Jn'
} 9U7nKJ+iby
,t3wp#E2#
G%BjhpL
} 2L!u1
x-XD.qh7Hr
;:iY)}
/* c7?_46J
**SiteInfoBean.java -Mip,EO
*/ P=qa::A
package NetFox; >3ZFzh&OYQ
f}6s Q5
o5d%w-'
public class SiteInfoBean { tE.FrZS
G`+T+
A4Rug\p]
private String sSiteURL; //Site's URL #HYr0Tw6`
private String sFilePath; //Saved File's Path 2{D{sa
private String sFileName; //Saved File's Name 9X[kEl
private int nSplitter; //Count of Splited Downloading File u\a#{G;Z
r+'qd)
w!#tTyk`
public SiteInfoBean() (XVw"m/ye
{//nSplitter的缺省值为5 M\vwI"
//default value of nSplitter is 5 Cmu@4j&
this("","","",5); iky|Tp
} Qd)q([
uOKCAqYa
zy?.u.4L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N%kt3vmQ_
{ zofa-7'Bn
sSiteURL= sURL; toLV4BtIG
sFilePath = sPath; #||}R[~P"
sFileName = sName; :1^LsLr5
this.nSplitter = nSpiltter; ><RpEnWZ<
G, 44va
p5Z"|\
} <5d~P/,
GC<l#3+
XND|h#i8
public String getSSiteURL() !NIhx109q
{ S O4u9V
return sSiteURL; dW)B1iUo!
} 2$9odD<r
Ac96 [
)(A]Ln4
public void setSSiteURL(String value) %}[i'rT>
{ AmvEf
sSiteURL = value; }\hVy(\c
} x`U^OLV
d+<G1w&z
%fc!2E9|
public String getSFilePath() ng[Ar`
{ 8G9s<N}5&u
return sFilePath; H=@}=aPf
} [I0:=yJ+
C'G/AU
\<.+rqa!
public void setSFilePath(String value) 63^O|y\W8
{ >l]Xz*HE
sFilePath = value; \jh'9\
} grS:j+_M2m
mkMq
yu;+o3WlK
public String getSFileName() t!*?dr
{ kv]~'Srk
return sFileName; Z"Zmo>cV4
} <x@}01~
YO#M/%^j
=w;F<M|Y
public void setSFileName(String value) :Uz|3gq
{ \O}E7-
sFileName = value; |^0XYBxQ
} H]P. x!I
J cPtwa;q@
+?F[/?s5qz
public int getNSplitter() -1 FPkp
{ LE&RY[
return nSplitter; W_||6LbZy
} a!ud{Dx
46$._h P
a<@1-j<
public void setNSplitter(int nCount) ztnFhJ<a$
{ MPCBT!o4Z
nSplitter = nCount; M:XSQ["6>V
} U [*FCD!~
} qT,Te
fg s!v7
5"^en# ?9
/* :imW\@u
**Utility.java ?QsQnQ
*/ VkvB<3
package NetFox; E4xj?m^(y=
|P[w==AAf
,eOB(?Ku
public class Utility { C+'/>=>a.
~{d$!`|a
%Da8{%{`Pc
public Utility() Mx&&0#;r
{ t'VV>;-RO=
YHkn2]^#A
n\QgOSr<
} |h-QP#]/
0Z~p%C<LW
//线程睡眠 Z?}dq-Vh&
public static void sleep(int nSecond) 'w!Cn>
{ 8?J&`e/
try{ ZU85P0
Thread.sleep(nSecond); V}bjK8$$
} 4y)P>c
catch(Exception e) | 1E|hh@k
{ |s'Po^Sy
e.printStackTrace (); ?a8^1:
} <d,b'<z s
} LwrUQ)
cFaaLUZk
//日志 M*!agh
public static void log(String sMsg) lU@]@_<
{ Xp >7iX!:
System.err.println(sMsg); u&`XB|~
} >CrA;\l
<<@bl@9'
5Eg1Q YVt
public static void log(int sMsg) 1|RANy
{ =5Q]m6-SgV
System.err.println(sMsg); 2-7IJ\
} jNTjSX
} 4^TG>j?M
[ad@*KFxy3
aAJU`=uq
/* OTy.VT|
**TestMethod.java aIJt0;
*/ ~5_Ad\n9
package NetFox; &Nj3h(Ll
@HQ`~C#Z'
)#P; x"
public class TestMethod { {kp"nl$<
9)}[7Mg:C
pi /g H
public TestMethod() ;-9=RI0
{ ///xx/weblogic60b2_win.exe $eD.W
try{ qm./|#m>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9 TvV=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,-izEr
SiteFileFetch fileFetch = new SiteFileFetch(bean); D&/kCi=R
fileFetch.start(); k,'L}SK
} 87Oad@FOr
catch(Exception e){e.printStackTrace ();} =o Xsb
ZNf6;%oGG
{)"iiJ
} '>&^zgr
} ~h3c|
M*z~gOZ
public static void main(String[] args) iTFdN}U
{ )0ea+ib
new TestMethod(); (5#nrF]
} NPCs('cd>?
} "l*Pd$sr
点击下载更多相关资料