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)); iYJ:P
} 5G @
for(int i=0;i<nEndPos.length-1;i++) sF-{(
{ F<H[-k*t/
nEndPos = nStartPos[i+1]; TkHyXOk"Ky
} _sLSl;/t
nEndPos[nEndPos.length-1] = nFileLength; `TwDR6&
} YD>5zV%!D
} 3h N?l :/b
Zcst$Aro
=ie8{j2:
//启动子线程 Lxz!>JO>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c$fi3O
for(int i=0;i<nStartPos.length;i++) su:~Xd
{ WRIOjQ:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]$Ud`<Xnx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yR}PC/>
nStartPos,nEndPos,i); Y%$@ZYW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GY%^!r
fileSplitterFetch.start(); v|~&I%S7
} [&H$Su}$0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^hL?.xj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F3uR:)4<M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fs+ CY
nEndPos = " + nFileLength); uT1xvXfqP
// fileSplitterFetch[nPos.length-1].start(); /1D]\k()
3X|7 R
j:k}6]p}
//等待子线程结束 5~8FZ-x
//int count = 0; F/8="dM
//是否结束while循环 +ftOJFkI
boolean breakWhile = false; `eZ +Pf".
-!_\4
MC\rx=cR\
while(!bStop) m 0jm$>:Z
{ F"I{_yleq'
write_nPos(); -O&u;kh4g
Utility.sleep(500); [te9ui%JS
breakWhile = true; R k'5L
F6'[8f
WxE^S ??|
for(int i=0;i<nStartPos.length;i++) VKGH+j[
{ (g(.gN]
if(!fileSplitterFetch.bDownOver) A8|DB@Bi
{ 6>L)
breakWhile = false; r [NI#wW
break; SK][UxoHm
} Wb)>APL
} c qWX*&2_
if(breakWhile) S<Rl?El<=
break; mHj3ItXUu
6(M^`&fl
;7/ ;4Z
//count++; 8,VX%CS#q
//if(count>4) xJcM1>cT>
// siteStop(); &Hl*Eg f
} yW@0Q:
5Yxs_t4
O4c[,Uq8~
System.err.println("文件下载结束！"); 85{2TXQ^%=
} .@5RoD[o
catch(Exception e){e.printStackTrace ();} \+9~\eeXb
} |M;tAG$,"y
6x]x>:8
76'@}wNnw
//获得文件长度 V?[dg^*0
public long getFileSize() r:.ydr@
{ mKTa.
int nFileLength = -1; PQ0l<]Y
try{ <]w(1{q(
URL url = new URL(siteInfoBean.getSSiteURL()); Sh@en\m=#S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k'6Poz+<
httpConnection.setRequestProperty("User-Agent","NetFox"); 5u:{lcC.X
4Y'Kjx
/7`fg0A
int responseCode=httpConnection.getResponseCode(); 6Wn"h|S
if(responseCode>=400) I38j[Xk
{ :Qc[>:N
processErrorCode(responseCode); (9!/bX<
return -2; //-2 represent access is error %B#(d)T*-
} <i1.W!%
7RpAsLH=
'B"A*!"b
String sHeader; tJ qd
AiDV4lHr
=cP7"\
for(int i=1;;i++) U??T>
{ =!R+0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FS+v YqwK
//Utility.log(in.readLine()); !dcGBj
sHeader=httpConnection.getHeaderFieldKey(i); p?Rq
if(sHeader!=null) 5YG%\
{ U %,K8u|WH
if(sHeader.equals("Content-Length")) QIb4ghm,
{ g!![%*' b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I k[{,p
break; P}2waJe
} 9im<J'
} 5H{dLZ],
else n[f<]4<
break; IncHY?ud<
} }#bX{?f
} kv8 /UW
catch(IOException e){e.printStackTrace ();} jI%g!
catch(Exception e){e.printStackTrace ();} ,Oj 53w=
2D vKW%;
'#*5jn]CqB
Utility.log(nFileLength); wI{ED
6@X j
<\6<-x(H5
return nFileLength; .29y3}[PO
} tR{@NFUcu
=7l'3z8
{E3329t|'
//保存下载信息（文件指针位置） lYq/ n&@_1
private void write_nPos() bdBFDg
{ %uUQBZ4
try{ WF&?OHf2
output = new DataOutputStream(new FileOutputStream(tmpFile)); n7$21*,
output.writeInt(nStartPos.length); No(p:Snbo
for(int i=0;i<nStartPos.length;i++) p]^?4
{ ]!mC5Ea
// output.writeLong(nPos); ;*AKeI2
output.writeLong(fileSplitterFetch.nStartPos); [W*xPXr*
output.writeLong(fileSplitterFetch.nEndPos); i,R+C.6{
} bAkCk]>5
output.close(); ]A#K;AW{U
} +jv&V%IL
catch(IOException e){e.printStackTrace ();} 2<X.kM?N{B
catch(Exception e){e.printStackTrace ();} ?z/ )Hkw
} %9HL"
<q<kqy5s-R
C%LXGMt
//读取保存的下载信息（文件指针位置） p2)563#RS
private void read_nPos() 4r+s" |
{ &X%vp?p
try{ F-&=N {+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :,~]R,tJQ
int nCount = input.readInt(); 7wA.:$
nStartPos = new long[nCount]; xn BL{ []
nEndPos = new long[nCount]; O)EA2`)E
for(int i=0;i<nStartPos.length;i++) Ug~]!L
{ ,JVWn>s
nStartPos = input.readLong(); AzlZe\V?)~
nEndPos = input.readLong(); g UAx8=h
} %.nZ@';.
input.close(); P)9$}9i
} gOSFvH8FU
catch(IOException e){e.printStackTrace ();} 2*5]6B-(
catch(Exception e){e.printStackTrace ();} KJQW))%e
} V W2+ Bs}
jSKhWxL;'
!h[xeLlU
private void processErrorCode(int nErrorCode) a%igc^GS2
{ OdWZYWj
System.err.println("Error Code : " + nErrorCode); +C8yzMN\
} ~IhLjE
$T-Pl57
9cMQ51k)E
//停止文件下载 4IUdlb
public void siteStop() Zk .V
{ Yfa`}hQ
bStop = true; +yO^,{8SE
for(int i=0;i<nStartPos.length;i++) M&q3xo"w
fileSplitterFetch.splitterStop(); W81dLeTZg
grWmF3c#
J.;{`U=:
} xJemc3]2
} ijuIf9!
//负责部分文件的抓取 >dU.ic?19
**FileSplitterFetch.java u.~`/O
*/ O S%
package NetFox; 4 >2g&);B
-l2aAK1M
J 6%CF2
import java.io.*; uNoP8U%*
import java.net.*; !YZ$WiPl
R{3vPG
6{8dv9tK
public class FileSplitterFetch extends Thread { Z+EN]02|
.r4M]1Of
5k]xi)%
String sURL; //File URL QH]G>+LI5
long nStartPos; //File Snippet Start Position vXUq[,8yf
long nEndPos; //File Snippet End Position W, YYL(L
int nThreadID; //Thread's ID Zy+EIx
boolean bDownOver = false; //Downing is over ?VCM@{9
boolean bStop = false; //Stop identical E,EpzB$_dj
FileAccessI fileAccessI = null; //File Access interface 873'=m&
M tD{/.D>
Ak=|wY{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q}(D^rGP3
{ ;"T,3JQPn6
this.sURL = sURL; wrJ:jTh
this.nStartPos = nStart; <JkmJ/X
this.nEndPos = nEnd; }u9wD08x
nThreadID = id; 2n3g!M6~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [e.@Yx_}
} rfwX:R6,g
G~$[(Fhk
j7u\.xu9
public void run() E!SxO~
{ g71|t7Q
while(nStartPos < nEndPos && !bStop) 16Gp nb
{ fk!P#
h^aUVuL/
'|~L9t
try{ YVT\@+C'
URL url = new URL(sURL); %!HBPLk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3^x C=++
httpConnection.setRequestProperty("User-Agent","NetFox"); 66jL2XU<
String sProperty = "bytes="+nStartPos+"-"; PZB_6!}2[F
httpConnection.setRequestProperty("RANGE",sProperty); "(cMCBVYdA
Utility.log(sProperty); E3`&W8
z($h7TZ$
/GUbc
InputStream input = httpConnection.getInputStream(); J*}Qnl+
//logResponseHead(httpConnection); ?loP18S b
F4$N:Jkl
s;NPY
byte[] b = new byte[1024]; XkE'k;AEx
int nRead; tIJ?caX5=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2,bLEhu
{ 6O9?":3;
nStartPos += fileAccessI.write(b,0,nRead); q(iM=IeiN
//if(nThreadID == 1) XeRbn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `^#V1kRmH
} =(%+S<}
ZlEH3-Zv
KDUa0$"
Utility.log("Thread " + nThreadID + " is over!"); 4qe!+!#$
bDownOver = true; lemE/(`a_
//nPos = fileAccessI.write (b,0,nRead); KBSO^<7
} 9EIOa/*
catch(Exception e){e.printStackTrace ();} |',$5!:0O
} H}}g\|r&
} @5Zg![G
n k@e#
sn=_-uoU
//打印回应的头信息 _A5.
public void logResponseHead(HttpURLConnection con) IN#Z(FMVC
{ X@cO`P
for(int i=1;;i++) 2F- ]0kGR|
{ ^9wQl!e ob
String header=con.getHeaderFieldKey(i); J3P)oM[
if(header!=null) rM5{R}+;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /_g-w93
Utility.log(header+" : "+con.getHeaderField(header)); pipO,n
else ;wF 0s
break; Q xg)Wb#
} J~,Ny_L
} *~H\#N|x
8IrA{UU
b0n " J`
public void splitterStop() %M KZ':m
{ I%qZMoS1h
bStop = true; !T3b]0z
} @GrQ/F7
H1^m>4ll9
cQOc^W
} nJ{vO{N
}}4u>1,~
y)%CNH)*x
/* AFN"#M
**FileAccess.java wr+r J
*//文件访问(定位，写) "S ~(|G
package NetFox; f:_mrzz
import java.io.*; 6r3.%V.&
LH_rc
/6@iRswa
public class FileAccessI implements Serializable{ Aq~}<qkIF+
/6@~XO)w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jXu)%<
RandomAccessFile oSavedFile; $-Wn|w+h<a
long nPos; (|kcSnF0
THcK,`lX@
G+dQ" cI9
public FileAccessI() throws IOException `<3xi9
{ /yhGc}h
this("",0); Jq8CII
} $MPh\T
KbP( ;
Iq%f*Zm<
public FileAccessI(String sName,long nPos) throws IOException FWu[{X;
{ y53f73Cg
oSavedFile = new RandomAccessFile(sName,"rw"); :e|[gEA
this.nPos = nPos; :1/K$A)^{
oSavedFile.seek(nPos); kafRuO~$
} d=J$H<
QhqXd
V% PeZ.Xv
public synchronized int write(byte[] b,int nStart,int nLen) dd{pF\a
{ oI2YJ2?Je8
int n = -1; t!S ja
try{ 9+!1jTGSkf
oSavedFile.write(b,nStart,nLen); |yT-N3H@
n = nLen; E` O@UW@
} C % d
catch(IOException e) d \[cFe1d
{ /j|Rz5@=
e.printStackTrace (); F[HMX4
} yCt,-mz!z
RD1N@sHDKc
#;*0 Pwe`
return n; U0Q:sA U
} : U:>X6f
q[rBu9
`~ ,
} |1z?#@BH
iJH;OV;P
.PHz
/* %%-hax.x0X
**SiteInfoBean.java A3jT;D9Y%
*/ D;RZE
package NetFox; aOWfu^&H:
ImnN&[Cu
IC[iCrB
public class SiteInfoBean { {y0`p1
s1/:Ts[3i
t^Hte^#S
private String sSiteURL; //Site's URL _Vj uQ
private String sFilePath; //Saved File's Path Ait3KIJ9
private String sFileName; //Saved File's Name k 6)ThIG
private int nSplitter; //Count of Splited Downloading File O,>`#?
[LcHO] _^M
/ZcqKC
public SiteInfoBean() :% o32
{//nSplitter的缺省值为5 `_*NFv1_
//default value of nSplitter is 5 K@DK4{
this("","","",5); _t+.I9kQ
} "h>B`S
`VB]4i}u
=5PNH2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f-M9OI
{ D. _*p
sSiteURL= sURL; iCK p"(kf
sFilePath = sPath; >AsrPU[
sFileName = sName; 9~FB^3Nz_
this.nSplitter = nSpiltter; [p7cgHSMt
e,0y+~
.JG>/+
} FSp57W$
eC71;"
:^Ouv1!e1
public String getSSiteURL() TAl#V7PF}
{ *;]j#0
return sSiteURL; pjI< cQ&
} b}eBy
?mjQN|D
^/k`URQ
public void setSSiteURL(String value) v o9Fj
{ O_n) 2t(c?
sSiteURL = value; pO~lVM
} `QIYnokL
w&F/P]1
H$j`75#u?-
public String getSFilePath() ) C?emTih
{ :gvw5h%
return sFilePath; GdxMHnn=
} "AAzBWd/
qxR7;/@j)
:W++`f&
public void setSFilePath(String value) in/ITy-
{ ee9nfvG-
sFilePath = value; $d[xSwang
} < mb.F-8
<o\2-fWvY
.%iJin"
public String getSFileName() Xw|t.0
{ ~gjREl,+D#
return sFileName; H /kSFf{
} +Je(]b@
5,pKv
:Ur=}@Dj
public void setSFileName(String value) ]nEZQ+F
{ ?\eq!bu
sFileName = value; v@8=u4
} 6axDuwQ
Ckelr
7i,Z c]
public int getNSplitter() kCq]#e~wq
{ 2L'vB1`
return nSplitter; wGXnS"L!
} 8\85Wk{b
e>:bV7h j~
c2,1d`
public void setNSplitter(int nCount) ^YpA@`n
{ NvZ )zE
nSplitter = nCount; n$ri:~s
} 7:Jyu/*]
} -]uN16\ F
?&H1C4
TvEN0RV2
/* Zv`j+b
**Utility.java +&w=*IAKZ
*/ q $Hg\ {c
package NetFox; XuQ7nlbnq
KvFGwq"X
fCA/
public class Utility { *=-o0c
gD[Fkq$]
OYWW<N+R2
public Utility() _Gpq=(q)
{ D~;hIt*
0NN{2"M$p
l>Nz]Ul%{
} ON(H7
GYx_9"J\5
//线程睡眠 ?H c~ 3
public static void sleep(int nSecond) j:yQP#U
{ rt7Ma2tK
try{ 2 us-s
Thread.sleep(nSecond); &*I\~;1
} suh@
catch(Exception e) jf&LSK;2
{ <eObQ[mQ
e.printStackTrace (); Bh9O<|E
} !Cm<K*c"&E
} %'}L.OvG
x,sMa*vd
//日志 a:PS}_.
public static void log(String sMsg) ^8mF0K&
{ X[frL)k]
System.err.println(sMsg); uc% &g
} > n~l\ fC
0/8rYBV
I 9yNTD
public static void log(int sMsg) h\ (z!7t*
{ #xqeCX4p
System.err.println(sMsg); 6\MJvg\;
} Wdt9k.hzN
} "d a%@Zy
`ym@U(;N
H!F Cerg
/* N0@&eX|$i4
**TestMethod.java 4T-9F
*/ +F &,,s"&
package NetFox; %!r>]M <
#?xhfSgr
RLypWjMx$
public class TestMethod { FuOP+r!H
Lx-ofN\
Lp; {&=PIo
public TestMethod() c2}?[\U]
{ ///xx/weblogic60b2_win.exe dOm#NSJVd
try{ f`5e0;zm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uzO%+B!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y$%/H"1bk
SiteFileFetch fileFetch = new SiteFileFetch(bean); 73$^y)AvY
fileFetch.start(); Ni$WI{e9
} YfC1.8
catch(Exception e){e.printStackTrace ();} P@Wi^svj
UTEUVcJ\
w_po5[]R
} }]pq&v!
ta>:iQa
v;S7i>\
public static void main(String[] args) (+<SR5,/3
{ |Ire#0Nwx
new TestMethod(); Do7&OBI~
} <RmI)g>'_^
} oYNP,8r^
点击下载更多相关资料