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)); Q+{xZ'o"Z
} AP?R"%
for(int i=0;i<nEndPos.length-1;i++) &w_j/nW^'
{ YJT&{jYi
nEndPos = nStartPos[i+1]; ~:s>aQ`!
} 12b(A+M
nEndPos[nEndPos.length-1] = nFileLength; r@H /kD
} "#2a8#
} nFHUy9q
^ B fC
)q8pk2
//启动子线程 K0|FY=#2y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W}@c|d $`
for(int i=0;i<nStartPos.length;i++) aC8} d
{ 65JF`]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V]lLw)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KQ% GIz x
nStartPos,nEndPos,i); {k TEHe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p>v$FiV2N
fileSplitterFetch.start(); Nk? ^1n$
} g}k`o!q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y!w`YYKP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wd8l$*F*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *&^Pj%DX
nEndPos = " + nFileLength); N/"{.3{W
// fileSplitterFetch[nPos.length-1].start(); 84& $^lNV
|4;Fd9q^m
"^})zf~_
//等待子线程结束 FrGgga$
//int count = 0; hF~n)oQ
//是否结束while循环 \/r}]Vz
boolean breakWhile = false; PR#exm&
k<CJ{u0<
7rc0yB
while(!bStop) &[?\k>
{ X!TpYUZ'
write_nPos(); Tztu}t]N
Utility.sleep(500); [ )Iv^ U9
breakWhile = true; Hw}Xbp[y
?jv/TBZX4
8mvy\l EEH
for(int i=0;i<nStartPos.length;i++) K7_UP&`=J
{ 5y.WMNNv{
if(!fileSplitterFetch.bDownOver) MzdV2.
{ & p
breakWhile = false; /|6N*>l)y
break; dd%6t
} 8Z8gRcv{p
} 2j[=\K]
if(breakWhile) JzQ_{J`k
break; 6,8h]?u.
)4e.k$X^
vtg!8u4
//count++; n,y ZRY
//if(count>4) ].w4$OJ?
// siteStop(); y@S$^jk.
} 3)<yod=
A4x]Qh3OO
t%0VJB,Q2
System.err.println("文件下载结束！"); yW=::=
} y&$A+peJ1
catch(Exception e){e.printStackTrace ();} NZ:,ph
} Y.(PiuG$G
%v M-mbX
Ju@c~Xm
//获得文件长度 EHJ.T~X
public long getFileSize() t\dN DS
{ :D5Rlfj
int nFileLength = -1; L\J;J%fz.
try{ ,f%S'(>w
URL url = new URL(siteInfoBean.getSSiteURL()); ~g]Vw4pv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I3L<[-ZE
httpConnection.setRequestProperty("User-Agent","NetFox"); zj{pJOM06
gD@){Ip
lgL%u K)
int responseCode=httpConnection.getResponseCode(); BA:VPTZq
if(responseCode>=400) N)X3XTY
{ IVY]EkEG~
processErrorCode(responseCode); Woym/[i
return -2; //-2 represent access is error reu*53r]
} NIry)'"
0 1rK8jX
Q->sV$^=T
String sHeader; i>`%TW:g
Naf0)3q>!
v0{i0%d,?
for(int i=1;;i++) W:2( .?
{ kiaw4_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ty?cC**
//Utility.log(in.readLine()); z2~til
sHeader=httpConnection.getHeaderFieldKey(i); /{g>nzP
if(sHeader!=null) kS);xA8s]
{ L~OvY
if(sHeader.equals("Content-Length")) b{&)6M)zo
{ M'O <h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?dg[:1R}
break; Se}c[|8
} j3V -LnA
} 194)QeoFw
else ydA8wL
break; TF\C@4Z
} S9y}
} v@L;x [Q
catch(IOException e){e.printStackTrace ();} U?Zq6_M&
catch(Exception e){e.printStackTrace ();} 6<QQ@5_
@Cyvf5|bL
4xje$/_d
Utility.log(nFileLength); WSB0~+
sY&IquK^
B~ GbF*j
return nFileLength; ! n@KU!&k
} N=}A Z{$
5|s\*bV`
kbQ>a5`,x
//保存下载信息（文件指针位置） #=A)XlZMd
private void write_nPos() LL~%f &_
{ IOmfF[
try{ qR8Lh( "i
output = new DataOutputStream(new FileOutputStream(tmpFile)); gR;i(81U
output.writeInt(nStartPos.length); hL{KRRf>
for(int i=0;i<nStartPos.length;i++) yNBfUj -L
{ .Yn_*L+4*
// output.writeLong(nPos); eq;uO6[
output.writeLong(fileSplitterFetch.nStartPos); }&J q}j
output.writeLong(fileSplitterFetch.nEndPos); {4Cmu;u
} FvjPdN/L?R
output.close(); dR,fXQm
} 29.h91
catch(IOException e){e.printStackTrace ();} ?k{?GtSs
catch(Exception e){e.printStackTrace ();} q>+k@>bk@
} JPw.8|V)y
]{@-HTt
uy$e?{Jf
//读取保存的下载信息（文件指针位置） YU'E@t5
private void read_nPos() 3F2w-+L
{ @#l= l
try{ ?CPahU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d\8l`Krs[_
int nCount = input.readInt(); !pX>!&sb
nStartPos = new long[nCount]; n{mfn*r.
nEndPos = new long[nCount]; ^u ~Q/4
for(int i=0;i<nStartPos.length;i++) E ~<JC"]
{ oZ|\vA%4^
nStartPos = input.readLong(); z<?)Rq"
nEndPos = input.readLong(); )jP1or
} fuySN!s
input.close(); 2c*GuF9(0
} BRiE&GzrF
catch(IOException e){e.printStackTrace ();} '~=SzO
catch(Exception e){e.printStackTrace ();} /a4{?? #e
} XW]tnrs
8{sGNCvU
_-g&PXH
private void processErrorCode(int nErrorCode) #@Jq~$N|
{ Ad_hKO
System.err.println("Error Code : " + nErrorCode); %Q|Atgp
} zK@@p+n_#.
HG^'I+Yn
&Z%?!.4j@
//停止文件下载 jNk%OrP]
public void siteStop() l]8uk^E
{ VMWf>ZU
bStop = true; pW3^X=6
for(int i=0;i<nStartPos.length;i++) 6j}9V L77
fileSplitterFetch.splitterStop(); 4,DeHJjAlE
Y$@?.)tY
Lp9E:D->
} oCz/HQoBk
} &F~T-i>X
//负责部分文件的抓取 vEJbA
**FileSplitterFetch.java Q*Pq{]0K
*/ H/M@t\$Dc
package NetFox; cbTm'}R(G
PdWx|y{%
5=ryDrx
import java.io.*; 6=Otq=WH
import java.net.*; _oeS Uzq.
oUlVI*~ND
ujpJ@OWj
public class FileSplitterFetch extends Thread { 3^yK!-Wp(
o66}yJzmD
xJ.M;SF4
String sURL; //File URL utV_W&
long nStartPos; //File Snippet Start Position IH+|}z4N?>
long nEndPos; //File Snippet End Position UkFC~17P
int nThreadID; //Thread's ID Z,PPu&lmE/
boolean bDownOver = false; //Downing is over =rdV ]{Wc
boolean bStop = false; //Stop identical tKXIk9e
FileAccessI fileAccessI = null; //File Access interface SE*g;Cvg1
j0q&&9/Jj
4j^ @wV'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {+>-7 9b
{ r9?Mw06Wc5
this.sURL = sURL; JB<t6+"rD
this.nStartPos = nStart; Jln:`!#fDf
this.nEndPos = nEnd; jnwu9PQ
nThreadID = id; TB31- ()
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^U/O!GK
} ZbKg~jdF
`Urhy#LC
$[ *w"iQ
public void run() ,I;>aE<#
{ ;!Fn1|)
while(nStartPos < nEndPos && !bStop) q!@4~plz
{ pd$[8Rmj_
_lq`a\7e
Tw<q,O
try{ 6_B]MN!(
URL url = new URL(sURL); ,PDQzJY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MF'JeM;H
httpConnection.setRequestProperty("User-Agent","NetFox"); 8LCb+^
String sProperty = "bytes="+nStartPos+"-"; kyV8K#}%8
httpConnection.setRequestProperty("RANGE",sProperty); "#g}ve,
Utility.log(sProperty); iWR)ke
<F'\lA9
P.DK0VgY
InputStream input = httpConnection.getInputStream(); #AY&BWS$
//logResponseHead(httpConnection); gjlx~.0d
+lTq^4
\Vk:93OH21
byte[] b = new byte[1024]; Q+{n-? :
int nRead; c &c@M$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |DwZ{(R"W
{ 0> \sQ,T
nStartPos += fileAccessI.write(b,0,nRead); eyxW 0}[
//if(nThreadID == 1) #O&8A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pg{J{gn
} m]&SNz=
t6t!t*jO
7d\QB(~
Utility.log("Thread " + nThreadID + " is over!"); /gas2k==^
bDownOver = true; 4skD(au8
//nPos = fileAccessI.write (b,0,nRead); %a7$QF]
} qxc[M8s
catch(Exception e){e.printStackTrace ();} x?<FJ"8"k
} mR)wX 6
} vP,n(reM
7xR\kL.,
_#8MkW#]~
//打印回应的头信息 "J1 4C9u
public void logResponseHead(HttpURLConnection con) -G=]=f/'
{ fV~[;e;U.
for(int i=1;;i++) vih9KBT
{ q,%st~
String header=con.getHeaderFieldKey(i); 1Z&(6cDY8M
if(header!=null) W*Y/l~x}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $:^td/p J
Utility.log(header+" : "+con.getHeaderField(header)); Ho]su?
else ;AG()NjOO:
break; 19] E 5'AI
} ee=D1qNu;
} +w~oH=
@(lh%@hO
7|H$ /]
public void splitterStop() }QmqoCAE~m
{ _u Il
bStop = true; xYB{;K
} nr3==21Om4
z@j8lv2j1
H,NF;QPPC
} rT>wg1:
Alq(QDs
qxj(p o
/* '<uq3?5
**FileAccess.java Xwtqi@zlE
*//文件访问(定位，写) jiC>d@~y
package NetFox; v` r:=K
import java.io.*; ,fRq5"?
Tsx>&WC
&nK<:^n
public class FileAccessI implements Serializable{ qJw_
y_[vr:s5pG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -n;}n:wL
RandomAccessFile oSavedFile; WY]s |2a
long nPos; d"Y{UE
yCo.cd-
d d;T-wa}
public FileAccessI() throws IOException @j/&m]6%-D
{ f *)Z)6E
this("",0); Q59W#e)
} t$ *0{w E
F:ELPs4"
&c #N)U
public FileAccessI(String sName,long nPos) throws IOException T]$U""
{ #A.@i+Zv
oSavedFile = new RandomAccessFile(sName,"rw"); :gC#hmm^
this.nPos = nPos; BJ0?kX@
oSavedFile.seek(nPos); 13wE"-
} 048kPXm`
DV{=n C
Hx:;@_gq
public synchronized int write(byte[] b,int nStart,int nLen) [00m/fT6
{ $od7;%
int n = -1; %XTI-B/K
try{ x)VJFuqy
oSavedFile.write(b,nStart,nLen); =\d?'dII:
n = nLen; DTs;{c
} }~q5w{_n
catch(IOException e) ']oQ]Yx0
{ [Nq*BrzF
e.printStackTrace (); 2?i7UvV
} L0]_X#s>#
1 {)Q[#l
%>s|j'{
return n; azU"G(6y?+
} wNX]7wMX
?%kV?eu'
8XbT`y
} mVmGg,
I2DpRMy
!o-@&q
/* YbLW/E\T
**SiteInfoBean.java |nF8gh~}
*/ L=h'Qgk%
package NetFox; ,[;G|et
*|l/6!WM
CQ2jP G*py
public class SiteInfoBean { <7$1kGlA
^}C\zW
U<-D(J
private String sSiteURL; //Site's URL uVU)d1N
private String sFilePath; //Saved File's Path zn(PI3+]!
private String sFileName; //Saved File's Name Ct|A:/z(
private int nSplitter; //Count of Splited Downloading File A70d\i
GJUL$9
FgI3
public SiteInfoBean() jq-_4}w?C
{//nSplitter的缺省值为5 3mni>*q7d
//default value of nSplitter is 5 y3ikWnx
this("","","",5); h.fq,em+H
} ,2)6s\]/b
!VK|u8i
)_NO4`ejs/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cS+>J@L
{ yppo6HGD
sSiteURL= sURL; Xm2'6f,
sFilePath = sPath; rN{ c7/|
sFileName = sName; 07$o;W@
this.nSplitter = nSpiltter; xwty<?dRW1
|)G<,FJQE_
(tQc
} vcd\GN*4f
{BHO/q3
[SW_C
public String getSSiteURL() ]s748+
{ ]9,;K;1<
return sSiteURL; FGQzoS
} v9UD%@tZ
#o2[hibq
Q5_o/wk
public void setSSiteURL(String value) lNBL4yM
{ M#[{>6>iE
sSiteURL = value; 6`-jPR
} ,?XCyHSgWW
bYPKh
'Z|mQZN
public String getSFilePath() .>nRzgo
{ 8sCv]|cn
return sFilePath; ],v=]+R
} {}Za_(Y,]
y)gKxRaCS
[c06 N$:
public void setSFilePath(String value) xP,hTE
{ YgoBHE0#
sFilePath = value; FsryEHz
} n-OL0$Xu
e~':(/%|5;
"wHFN>5B
public String getSFileName() ~3 bPIg7D
{ E+JqWR5
return sFileName; :/Qq@]O>
} ?pZOeqqu$
kSh( u
z$xo$R(
public void setSFileName(String value) GM<-&s!Uj
{ Wxe0IXq3Nn
sFileName = value; e 3TI|e_
} &8 x-o,
BVO<e \>3
K96<M);:g
public int getNSplitter() !0cD$^7
{ "-J-k=
return nSplitter; ?I@W:#>o
} ia 73?*mXT
?K\axf>F
ZQ0F$J)2~
public void setNSplitter(int nCount) :08,JL{
{ ?S$P9^ii'
nSplitter = nCount; xF44M]i
} U`m54f@U
} (J!+(H8
Z)aUt Srf
&9)\wnOS
/* Ez=Olbk
**Utility.java # 4PVVu<
*/ 9*?oYm;dX
package NetFox; d<N:[Y\4l
N*&1GT#9
xK\d4"
public class Utility { \;"=QmRD%:
f`=-US
\} :PLCKT
public Utility() *=7U4W
{ ,nB5/Lx
tC9n k5~
g'qa}/X
} N'`A?&2ru
A$:U'ZG_
//线程睡眠 w:Kl6"c
public static void sleep(int nSecond) q#=(e:aCb
{ 5N&?KA-
try{ J~UuS+Ufv
Thread.sleep(nSecond); Tyf`j,=
} Eg3q!J&Z
catch(Exception e) C-[eaHJ'$
{ 'ub@]ru|
e.printStackTrace (); $'hEz/
} OH(waKq2I
} +&2%+[nBZ
%n:k#
//日志 r|Tcfk]%
public static void log(String sMsg) KNIn:K^/
{ )f<z%:I+Z
System.err.println(sMsg); u^qT2Ss0
} ah+iZ}E%
wx0j(:B]
X*@dj_,
public static void log(int sMsg) xx%j.zDI]
{ r #cGop]
System.err.println(sMsg); _8_R 1s
} psMvq@>
} *6DB0X_-}
g~A`N=r;h
-:y,N 9^
/* P! #[mio
**TestMethod.java +s DV~\Vu
*/ T <ET )D7
package NetFox; &AbNWtCV+G
*.d)OOpLo
\Et3|Iv
public class TestMethod { oHn Ky[1
=.]4;z
SmSH2m-
public TestMethod() U/l&tmIVY
{ ///xx/weblogic60b2_win.exe 'Xq|Kf (
try{ o]M5b;1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DwE[D]7o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T!WT;A
SiteFileFetch fileFetch = new SiteFileFetch(bean); AogVF
fileFetch.start(); !\.pq 2
} jQ^|3#L\
catch(Exception e){e.printStackTrace ();} R3&Iu=g
54R#W:t
!_'ur>iR
} '=8d?aeF
'XP7" N47O
MJ [m
public static void main(String[] args) LR.<&m%~.
{ 41?HY{&2
new TestMethod(); /zVOK4BqN+
} %%gc2s
} !/i{l
点击下载更多相关资料