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)); oJhEHx[f
} [;)~nPjI
for(int i=0;i<nEndPos.length-1;i++) Z=0iPy,m>
{ -v;iMEZ)
nEndPos = nStartPos[i+1]; FW/6{tm
} 4GEjW4E
nEndPos[nEndPos.length-1] = nFileLength; R%Kl&c
} gX/|aG$a!U
} 7l[t9ON
)kFme=;
_.u~)Q`6
//启动子线程 jY1^+y{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hLu&lY
for(int i=0;i<nStartPos.length;i++) JiG8jB7%}
{ Kv(Y }
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Z#<tN;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \xy:6gd:
nStartPos,nEndPos,i); 4KN0i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,q{lYX83S
fileSplitterFetch.start(); T[`QO`\5O
} hj%}GP{{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [RroHXdk+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =f/avGX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C6Um6X9/i
nEndPos = " + nFileLength); @Z"QA!OK~c
// fileSplitterFetch[nPos.length-1].start(); 4yJ01s
89 _&X[X
Ly@U\%.
//等待子线程结束 \Qe'?LRu{
//int count = 0; qdg= Imx
//是否结束while循环 &QiAM`MbC=
boolean breakWhile = false; Ke'YM{
Z3&XTsq
_p3WE9T
while(!bStop) ."$=
{ O% j,:t'"
write_nPos(); ;tZ}i4Ud
Utility.sleep(500); )AZ`R8-A
breakWhile = true; oZ|{J
6'3Ey'drH
*}50q9)/
for(int i=0;i<nStartPos.length;i++) NpjsZcA
{ R$~JhcX*l'
if(!fileSplitterFetch.bDownOver) 4jI*Y6Wkz
{ ~8S4Kj)%
breakWhile = false; PDa06(t7
break; ePFC$kMn
} )[a?J,
} .>cL/KaP
if(breakWhile) i1kh@s~8UC
break; O;.d4pO(tC
EV;;N
[m@e^6F0U
//count++; iyHp$~,q?t
//if(count>4) la6e`
// siteStop(); Q'vIeG"o
} 0.3[=a43
U7f#Z
`\}zm~
System.err.println("文件下载结束！"); cc#_acR
} ]MBJ"1F
catch(Exception e){e.printStackTrace ();} *AJezhR
} tF)k6*+
p5D3J[?N
9=sMKc%!-
//获得文件长度 pNk,jeo
public long getFileSize() 5}(YMsUb
{ TbSt{TX
int nFileLength = -1; c"_H%x<[
try{ v:so85(S<
URL url = new URL(siteInfoBean.getSSiteURL()); d%"@#bB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \1c`)
httpConnection.setRequestProperty("User-Agent","NetFox"); =Am*$wGI
JhhT7\h(
L<nkI
int responseCode=httpConnection.getResponseCode(); 2+hfbFu,1
if(responseCode>=400) )QJU]G
{ 67hPQ/S1
processErrorCode(responseCode); XzTH,7[n
return -2; //-2 represent access is error uR[PKLh
} <]SSgQ9/"
|'>E};D
,1.([%z+r
String sHeader; .$T:n[@
+xu/RY_
QK/+*hr;
for(int i=1;;i++) ?5+KHG*)
{ D-\'P31
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mk3e^,[A
//Utility.log(in.readLine()); M#gGD-
sHeader=httpConnection.getHeaderFieldKey(i); .]d tRH<
if(sHeader!=null) >ehWjL`8
{ h,RUL
if(sHeader.equals("Content-Length")) QR-R5XNT[
{ 9G\3hL]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f4;8?
break; u:>3j,Cs
} U=<.P;+f9
} W1,L>Az^Ts
else FT?1Q'
break; UK9MWC5g9
} It:QXLi;
} :FgRe,D
catch(IOException e){e.printStackTrace ();} }\qdow-
catch(Exception e){e.printStackTrace ();} jm!C^5!
.mU.eLM
xbC-ueEj
Utility.log(nFileLength); |~vQ0D
<$Kv^Y*
vCe<-k
return nFileLength; ?F), 4Q
} ~;4k UJD
3e<^-e)+xL
2A;[Ek6{q
//保存下载信息（文件指针位置） =id $
private void write_nPos() CoN/L`.SN
{ uTt:/gm
try{ Rm1`D
output = new DataOutputStream(new FileOutputStream(tmpFile)); >u[1v
output.writeInt(nStartPos.length); Yt<PKs#E
for(int i=0;i<nStartPos.length;i++) sWCm[HpG
{ 9@a;1Wr/f
// output.writeLong(nPos); g#2X'%&+
output.writeLong(fileSplitterFetch.nStartPos); e9~4wt
output.writeLong(fileSplitterFetch.nEndPos); t'/;Z:
} )CTM
output.close(); :|mkI#P.
} E"yf!*
catch(IOException e){e.printStackTrace ();} swgBPJ"?
catch(Exception e){e.printStackTrace ();} UN4)>\Y
} D}U<7=\3H
#C7j|9Ew1]
PGhZ`nl
//读取保存的下载信息（文件指针位置） >RnMzH/9
private void read_nPos() ?YykCJJ ~@
{ RUtS_Z&
try{ ~,1q :Kue
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m =F@CA~C
int nCount = input.readInt(); 0>MI*fnY"
nStartPos = new long[nCount]; 'U0I.x(
nEndPos = new long[nCount]; JB_`lefW,'
for(int i=0;i<nStartPos.length;i++) Xkm2C)
{ sYI':UQe
nStartPos = input.readLong(); dkp[?f)x
nEndPos = input.readLong(); LkB!:+v |B
} sB/s17ar
input.close(); v('d H"Y
} PCfs6.*5Mf
catch(IOException e){e.printStackTrace ();} nGd
catch(Exception e){e.printStackTrace ();} 1y;zPJ<ntm
} wKbymmG
W-QPO
93DBZqN
private void processErrorCode(int nErrorCode) wO%:WL$5
{ ]w_)Spo.
System.err.println("Error Code : " + nErrorCode); `{_PSzM
} Rw 8o]
ZHasDZ8
Lc?O K"[m
//停止文件下载 Acv{XnB
public void siteStop() tY=TY{RY
{ c10).zZ
bStop = true; Z?mg1;Q
for(int i=0;i<nStartPos.length;i++) ;BVhkWA
fileSplitterFetch.splitterStop(); p2(_YN;s
LTct0Gh
db~:5#*
} /vMyf),2
} XCriZ|s
//负责部分文件的抓取 3~la/$?p0
**FileSplitterFetch.java b15qy?`y
*/ j #YFwX4.
package NetFox; J@iN':l-
3Q)>gh*
nWu4HFi
import java.io.*; elgQcJ99
import java.net.*; `p|vutk)U
>#|Yoc
vDvGT<d
public class FileSplitterFetch extends Thread { ^W'[l al.
o |iLBh$)
ulM&kw.4i
String sURL; //File URL ;~1JbP
long nStartPos; //File Snippet Start Position w'XgW0j{
long nEndPos; //File Snippet End Position efR$s{n!
int nThreadID; //Thread's ID NM.B=<Aw*
boolean bDownOver = false; //Downing is over `1]9(xwhQ0
boolean bStop = false; //Stop identical fk1f'M)/8
FileAccessI fileAccessI = null; //File Access interface >t(@?*ZFT
%'z3es0
): C4}&l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3)SZVME1Z
{ Q$j48,e
this.sURL = sURL; ;$< ek(i7
this.nStartPos = nStart; }wXD%X@)l
this.nEndPos = nEnd; t7FQ.E,T
nThreadID = id; mA@+4&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {[*_HAy7
} jF9CTL<
m)}MkC-
aM!#
public void run() G- WJlu
{ I_7EfAqg(
while(nStartPos < nEndPos && !bStop) It-*CD9
{ q2vz#\A?
He3zV\X[Z
9zd/5|W
try{ @x +#ZD(
URL url = new URL(sURL); / u6$M/Cf>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Q)}
httpConnection.setRequestProperty("User-Agent","NetFox"); kELyD(^P`
String sProperty = "bytes="+nStartPos+"-"; 1A-EP@# J
httpConnection.setRequestProperty("RANGE",sProperty); #jiqRhm
Utility.log(sProperty); yTiqG5r
g1,
&S]v+wF
InputStream input = httpConnection.getInputStream(); ~7'.{VrU
//logResponseHead(httpConnection); &Sa~Wtm|*
rK|&u v*b
Ya 4$7|(
byte[] b = new byte[1024]; P^W47 SO
int nRead; 3=7h+ZgB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) krc!BK`V
{ ^#se4qQ
nStartPos += fileAccessI.write(b,0,nRead); -74T C
//if(nThreadID == 1) >/bK?yT<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DjvgKy=Jr_
} B)8Hj).@B
}* JMc+!9@
8-YrmP2k
Utility.log("Thread " + nThreadID + " is over!"); WEAXqDjM
bDownOver = true; +Ob#3PRy
//nPos = fileAccessI.write (b,0,nRead); );H[lKy
} >nEnX
catch(Exception e){e.printStackTrace ();} _!p3M3"$B
} r0 C6Ww7u
} cLC7U?-
NI:N W-!
^I?y\:.
//打印回应的头信息 ;NeEgqW"
public void logResponseHead(HttpURLConnection con) MiM=fIuw@s
{ 1Z8oN3
for(int i=1;;i++) ] Nipo'N;
{ aZ`agsofk
String header=con.getHeaderFieldKey(i); ;@~*z4U
if(header!=null) >Fk`h=Wd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T?{9Z
Utility.log(header+" : "+con.getHeaderField(header)); v=-3 ,C
else Qp&ySU8
break; gi@ji-10
} q.km>XRk~
} wJ*-K-
[{LnE:
X.9MOdG70
public void splitterStop() eH/\7)z
{ AiHf?"EVT
bStop = true; ?u!AHSr(
} bKZ#>%|:o
>I~z7JS
^QR'yt3e
} ;o459L>sW
w1(06A}/
v};qMceJ
/* u(WQWsN
**FileAccess.java >ImM~SR)
*//文件访问(定位，写) 1t=X: ]0j
package NetFox; dU^<7 K:S
import java.io.*; ATp 6-
C?|3\@7
,!u@:UBT
public class FileAccessI implements Serializable{ ?QT"sj64w
HTyF<K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~7WXjVZ
RandomAccessFile oSavedFile; m>dcb 6B+g
long nPos; y]f^`2L!8>
fYM6wYJ
(H%d]
public FileAccessI() throws IOException CVG>[~}(9'
{ EFt`<qwj
this("",0); <`UG#6z8
} nYt\e]3
T&"dBoUq>G
`G0rF\[
public FileAccessI(String sName,long nPos) throws IOException @"Fp;Je\bN
{ w[oQ}5?9'
oSavedFile = new RandomAccessFile(sName,"rw"); ?iEXFYJG
this.nPos = nPos; dN/ "1%9)
oSavedFile.seek(nPos); e0WSHg=6@
} |aAWWd5
=C>`}%XT}
zQ %z"tQ
public synchronized int write(byte[] b,int nStart,int nLen) 2*wO5v
{ >fA@tUQB
int n = -1; \"`>-v"h
try{ UAXF64w{
oSavedFile.write(b,nStart,nLen); `pd
n = nLen; GKujDx+h
} giPo;z\c
catch(IOException e) /uXRZ
{ [^}>AC*im
e.printStackTrace (); <*Kh=v
} t^_{5
\i;&@Kp.N
j[J@tM#
return n; <kXV1@>
} P[GX}~_k
Pn'(8bRm
/.kna4k
} j YIV^o 0
m{$tO;c/Q
h$7Fe +#I#
/* q?-3^z%u
**SiteInfoBean.java ncJFB,4
*/ feI[M;7u
package NetFox; Z~phOv
=Q8H]F
jFNs=D&(
public class SiteInfoBean { S|q!? /jqj
1u"*09yZd
vMZ7uO
private String sSiteURL; //Site's URL AXh3LA
private String sFilePath; //Saved File's Path ZkB6bji
private String sFileName; //Saved File's Name ,8=`*
private int nSplitter; //Count of Splited Downloading File "?eH=!
f*T)*R_
i+X2M-[Ls
public SiteInfoBean() 29iIG 'N
{//nSplitter的缺省值为5 a?,[w'7FU
//default value of nSplitter is 5 >)n4sMq
this("","","",5); s@ 20#D
} ~6-"i0k
u3*NO )O
Od!F: <
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iJZ|[jEDV
{ n-hvh-ZO
sSiteURL= sURL; ||=[kjG~
sFilePath = sPath; W%>i$:Qq
sFileName = sName; =CKuiO.j
this.nSplitter = nSpiltter; Y%fVt|
y^d[( c
z#{0;t
} gv#c~cX]
:>P4L,Da]
.|-l+
public String getSSiteURL() Q&Z4r9+Z
{ b.R!2]T]i^
return sSiteURL; SLdN.4idK
} Qst \b8,
crJ7pe9
f2O*8^^Y{Q
public void setSSiteURL(String value) zNV!@Yr
{ Np|'7D
sSiteURL = value; W,HH *!
} \K?(
cPq Dsl3
X-)RU?
public String getSFilePath() )D["M$ZA^
{ af<NMgT2s~
return sFilePath; IpWy)B>Fl3
} $hjP}- oUX
OU,PO2xX9
29Gwv
public void setSFilePath(String value) ~!]&>n;=G
{ Ml8 YyF/~
sFilePath = value; n+{HNr
} ~K~b`|1
qIbg 4uE
rU=b?D)n!w
public String getSFileName() (C`FicY
{ O{k89{
return sFileName; E0"10Qbi
} I 1b
$J QWfGwR
Q_&}^
public void setSFileName(String value) 0?lp/|K
{ ~L%Pz0Gg
sFileName = value; M}Nb|V09
} $!YKZ0)B'0
0'?V|V=v
vKNt$]pm=
public int getNSplitter() q2x|%HRF
{ 4%g6_KB
return nSplitter; P%zH>K
} 1t/dxB;
W@I 02n2H
q>_vE{UB
public void setNSplitter(int nCount) =n@F$/h
{ #ZG3|#Q=L
nSplitter = nCount; -VS9`7k
} C#MFpT
} M{`/f@z(
YfE>Pn'r
$ A-+E\vQ@
/* JDLTOLG
**Utility.java &w+;N5}3
*/ ;i<$7MR.e
package NetFox; ic%?uWN
.6> hD1'
3B@y &a#&
public class Utility { wYZT D*A2h
0:Ar|to$m
3gb|x?
public Utility() U'tE^W
{ M]}l^m>L
2Y400
>(hSW~i~
} ePf+[pV3
S8 :"<B)
//线程睡眠 (+|X<Bl:`
public static void sleep(int nSecond) LmP qLH'(Q
{ q5Fs)B
try{ q`XW5VV{K
Thread.sleep(nSecond); 7FAIew\r
} lB1#
catch(Exception e) p6`Pp"J_tr
{ z< z*Wz
e.printStackTrace (); 0y)}.'
} o4$Ott%Wm
} gfi AK%
KX!i\NHz
//日志 M70c{s`w5
public static void log(String sMsg) 94\t1fE
{ 2ck4C/ h
System.err.println(sMsg); pX@Si3G`
} m23+kj)+VY
g3Z:{@m
l :/&E 6 9
public static void log(int sMsg) ,Du@2w3Cq
{ N;uUx#z
System.err.println(sMsg); ?a S%
} 4t04}vp
} `>s7M.|X
mw_ E&v
-K"4rz
/* ^$!987"
**TestMethod.java W4(v6>5l
*/ sONBQ9
package NetFox; o/C(4q6d
g& k58{e
$[g_=Z
public class TestMethod { !=3Rg-'d1
Guh%eR'Wt
rz6uDJ"
public TestMethod() :p' VbQZ{
{ ///xx/weblogic60b2_win.exe qz9tr
try{ ~3gru>qI&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [QT1Ju64
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ({4]
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,|+Gls
fileFetch.start(); vv6?V#{
} j Fma|y
catch(Exception e){e.printStackTrace ();} EM@;3.IO
d6`OXTD
3\AM=`
} .e@>
LOr|k8tL%
,vV]"f
public static void main(String[] args) R[LsE^
{ )t:7_M3
new TestMethod(); scW'AJJq
} _d@=nK)
} Bn?:w\%Ue
点击下载更多相关资料