http断点续传简单实现（java)

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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)); )'!ml
} ]bN&5.|
for(int i=0;i<nEndPos.length-1;i++) ,t%CK!8
{ ?S@R~y0K
nEndPos = nStartPos[i+1]; }-{b$6]
} `[@^m5?b-
nEndPos[nEndPos.length-1] = nFileLength; 2rO)qjiH
} M*O(+EM
} &cu] vw
*hZ~i{c,7
;Lsjh#
//启动子线程 GL5^_`n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i9;27tT~<
for(int i=0;i<nStartPos.length;i++) }*.:Hv"
{ 4aN+}TkH@G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eyf4M;goz}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /~Zc}o,J
nStartPos,nEndPos,i); ~)wwX:;B_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wrQydI
fileSplitterFetch.start(); R2N^'
} 13.{Y)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bk7^%O>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &gWMl`3^*!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @TA8^ND
nEndPos = " + nFileLength); JN&MyA"
// fileSplitterFetch[nPos.length-1].start(); m)@Q_{=6M
Mr=}B6`
K5!";V
//等待子线程结束 3s?v(1 {)
//int count = 0; t&R!5^R
//是否结束while循环 C|4U78f{
boolean breakWhile = false; &@4.;u
NWJcFj_
p*pn@z
while(!bStop) Iys6R?~
{ HZDk <aU/!
write_nPos(); { r6]MS#l1
Utility.sleep(500); O1?B{F/ e
breakWhile = true; 1 [fo'M
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+R "AA_A?
for(int i=0;i<nStartPos.length;i++) *CeQY M
{ ;Ze"<U
if(!fileSplitterFetch.bDownOver) 5jn$7iE`
{ ,VKQRmd
breakWhile = false; 0W~.WkD
break; :%/\1$3P
} 0rku4T
} .Lojzx
if(breakWhile) 20rN,@2<
break; n> MD\ZS
N@cMM1
bbd0ocva
//count++; Lzh9DYU6
//if(count>4) @+?+6sS
// siteStop(); AA))KBXq
} >vQ6V'F
_&W0e}4
kU#:I9PO
System.err.println("文件下载结束！"); f\h%; X
} ,dHP`j ?
catch(Exception e){e.printStackTrace ();} z@!^ow)`J
} Y*Y&)k6t
tCWJSi`IJ
cwu$TP A>
//获得文件长度 <9@&oN+T
public long getFileSize() X$BXT
{ `Uzs+k-]
int nFileLength = -1; sL)Rg(rkx
try{ ?N4A9W9
URL url = new URL(siteInfoBean.getSSiteURL()); ]dd[WHA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LsQs:O
httpConnection.setRequestProperty("User-Agent","NetFox"); $!a?i@
>W8bWQ^fK
{V[Ha~b%*
int responseCode=httpConnection.getResponseCode(); ;US83%*
if(responseCode>=400) dKU5;
{ %z1{Kus
processErrorCode(responseCode); z8b _ _%Br
return -2; //-2 represent access is error +``>,O6
} d2ohW|
&c20x+
ZR1+ O8
String sHeader; LPq2+:JpS
DXKyRkn6e
Ip>^O/}$1
for(int i=1;;i++) h=hoV5d@
{ DeA@0HOxh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }g}6qCv7
//Utility.log(in.readLine()); 3nwz<P
sHeader=httpConnection.getHeaderFieldKey(i); !loO%3_)
if(sHeader!=null) ]a)IMIh;
{ lNHNL a>W
if(sHeader.equals("Content-Length")) yHl@_rN sC
{ M6\7FP6G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @|^jq
break; Z%Vr+)!4
} DX|uHbGg
} pw!@Q?R
else {n\6BTs
break; 'w}p[(
} bpGzTU
} HP;|'b
catch(IOException e){e.printStackTrace ();} Wt(Kd5k0'2
catch(Exception e){e.printStackTrace ();} ?;Un#6b
=Qyqfy*@D?
6mwvI4)
Utility.log(nFileLength); # 2d,U\_
PDhWFF
,`<]>;s
return nFileLength; Bgf=\7;5
} mLJDxh'B
$>;a'f~
$;y1Qiel
//保存下载信息（文件指针位置） Cgo9rC~]
private void write_nPos() gTnS[
{ oK)[p!D?0{
try{ B0v|{C
output = new DataOutputStream(new FileOutputStream(tmpFile)); fO#?k<p
output.writeInt(nStartPos.length); ,pn)>
for(int i=0;i<nStartPos.length;i++) 9MT3T?IS
{ 3#9uEDdE
// output.writeLong(nPos); RXM}hqeG
output.writeLong(fileSplitterFetch.nStartPos); am2a#4`
output.writeLong(fileSplitterFetch.nEndPos); A$Wx#r7)
} 0EyAMu
output.close(); 691G15
} =9(tsB gTX
catch(IOException e){e.printStackTrace ();} X\kjAMuW/*
catch(Exception e){e.printStackTrace ();} NK~PcdGl
} {b2 aL7
_1P`]+K\D$
)'`CC>Q
//读取保存的下载信息（文件指针位置） |!oXvXU
private void read_nPos() lO[E[c G
{ q4)Ey
try{ GJvp{U}y9I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n_J5zQJ
int nCount = input.readInt(); Jns/v6
nStartPos = new long[nCount]; <z',]hy
nEndPos = new long[nCount]; +ZX.1[O
for(int i=0;i<nStartPos.length;i++) Y3<b~!f
{ X CzXS.
nStartPos = input.readLong(); +|9f%f6vp
nEndPos = input.readLong(); $5x]%1R
} 5\&]J7(
input.close(); };^}2Xo+
} ]'tJ S]
catch(IOException e){e.printStackTrace ();} 4b=Gg
catch(Exception e){e.printStackTrace ();} \KCWYi]
} L$SMfx
T!(sZf
TywK\hH
private void processErrorCode(int nErrorCode) .D!WO
{ w]}f6VlEl
System.err.println("Error Code : " + nErrorCode); ^(DL+r,
} J B(<.E2
5~QTg
1)'Iu`k/
//停止文件下载 [EER4@_
public void siteStop() 7/ t:YBR
{ xdqK.Z%
bStop = true; 7C?E z%a@
for(int i=0;i<nStartPos.length;i++) Tv1]v.
fileSplitterFetch.splitterStop(); ;5N41_hG
^;4YZwW5w
12-EDg/1
} }Bi@?Sb
} B>,A(X&
//负责部分文件的抓取 \qB6TiB/
**FileSplitterFetch.java ~@@ Z|w
*/ W6i3Psjsw
package NetFox; qW3x{L$c
}1Z6e[K?
i\ "{#
import java.io.*; :Pf>Z? /d
import java.net.*; WI{;#A
:xtT)w
@<a|
public class FileSplitterFetch extends Thread { M|H2kvl
pr/'J!{^
K'V 2FTJI
String sURL; //File URL cl_TF[n?
long nStartPos; //File Snippet Start Position a MsJO*;>
long nEndPos; //File Snippet End Position 3Soy3Xp
int nThreadID; //Thread's ID ,WGc7NN`
boolean bDownOver = false; //Downing is over %0zS
boolean bStop = false; //Stop identical 'gCZ'edM
FileAccessI fileAccessI = null; //File Access interface ~5T$8^K
']h IfOD"r
lCHo+>\Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?aFZOc4
{ 5aG5BA[N
this.sURL = sURL; (2tH"I
this.nStartPos = nStart; LZa% x
this.nEndPos = nEnd; xj7vI&u.
nThreadID = id; n$xszuNJ`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MOeoU1Hn
} ZJvo9!DL|
hX3@f;[B2
QvJZkGX
public void run() =|"=l1
{ 2LC w*eT{)
while(nStartPos < nEndPos && !bStop) q~M2:SN@X
{ OT@yPG
_@K YF)
7f* RM
try{ r>O|L%xpv
URL url = new URL(sURL); \OY}GRKt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :X Lp
httpConnection.setRequestProperty("User-Agent","NetFox"); 2lo:a{}j
String sProperty = "bytes="+nStartPos+"-"; |EEi&GOR(y
httpConnection.setRequestProperty("RANGE",sProperty); QXY}STs
Utility.log(sProperty); x)5LT}p
kV+ R5R
MyFCJJ/
InputStream input = httpConnection.getInputStream(); _ Mn6L=
//logResponseHead(httpConnection); wPgDy
SiR\a!,C
mrqaM2,(I
byte[] b = new byte[1024]; g>T
int nRead; ai9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s[T{c.F
{ /B[}I}X
nStartPos += fileAccessI.write(b,0,nRead); U!Mf]3
//if(nThreadID == 1) `S$sQ&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t\%%d)d9
} . pP7"E4]
,cD1{T\
L;lk.~V4T
Utility.log("Thread " + nThreadID + " is over!"); 32^#RlSu8
bDownOver = true; @,e8t BL
//nPos = fileAccessI.write (b,0,nRead); #9,=Owup
} \4QH/e
catch(Exception e){e.printStackTrace ();} B\0t&dai|'
} Eu4 &-i
} zi.mq&,]R
z7k$0&
P5P<"
//打印回应的头信息 2LZS|fB9o
public void logResponseHead(HttpURLConnection con) Qt~B#R. V
{ (Vap7.6;_
for(int i=1;;i++) Z'ao[CG
{ aaT5u14%
String header=con.getHeaderFieldKey(i); ,5. <oDH
if(header!=null) |*fNH(8&H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t)'dF*L
Utility.log(header+" : "+con.getHeaderField(header)); .pW o>`"
else nALnB1
break; 7UDq/:}Fo
} L#!$hq9{_
} ~j]dct7
rKT)!o'
?Q?598MC
public void splitterStop() #Qsk}Gv
{ X Ny Y$
bStop = true; ZRPy~wy>
} j.B>v\b_3
f~R[&q+
A_i zSzC1
} bBG/gQ
N6q5`Ry
{#9,j]<
/* qy&\Xgn;GA
**FileAccess.java J'Gm7h{
*//文件访问(定位，写) gi1j/j7
package NetFox; xU:4Y0y8
import java.io.*; `0z/BCNB
B.RRdK+:
:~erh}~ps
public class FileAccessI implements Serializable{ 8,y{q9O
m_$JWv\|\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K( z[}
RandomAccessFile oSavedFile; MHFaSl
long nPos; 3sb 5E]P
vzcz<i )
ydup)[n
public FileAccessI() throws IOException {lMqcK
{ j-6v2MH
this("",0); 82s5VQ6
} pl?kS8#U?
k,lqT>C
l#ZyB|
public FileAccessI(String sName,long nPos) throws IOException 4&]%e6,jH
{ 1J&#&\,f&
oSavedFile = new RandomAccessFile(sName,"rw"); BCBUb
this.nPos = nPos; #fN/LO
oSavedFile.seek(nPos); L^)qe^%3
} C/
*_#&"(P
g&kH'fR8
public synchronized int write(byte[] b,int nStart,int nLen) O{nC^`X
{ g}YToOs
int n = -1; B*2{M
try{ zsQF,7/}B
oSavedFile.write(b,nStart,nLen); PqI![KxZW
n = nLen; %z2oDAjX
} RQ|?Ce",
catch(IOException e) nNu[c[V
{ Pj._/$R[/
e.printStackTrace (); W8VO)3nmD
} KX=/B=3~
H>Ks6V)RL4
80HEAv,O
return n; \6i9q=
} jceHKl
L\YZT| K(
%UBPoq
} O"8P#Ed
wR(ttwxK3
A(NEWO
/* wa2~C [
**SiteInfoBean.java Hva{A #
*/ a}w&dE$!-
package NetFox; pJn>oGeJ&
@BXaA0F4
Kn.iyR
public class SiteInfoBean { Lg b
1 0V+OIC
FbuKZp+
private String sSiteURL; //Site's URL c[Yq5Bu{y
private String sFilePath; //Saved File's Path ]a=l^Pc(xN
private String sFileName; //Saved File's Name PB@-U.Z
private int nSplitter; //Count of Splited Downloading File $6Z[|9W^A
ah>Dqb*
9T/<x-FD
public SiteInfoBean() sI$:V7/!
{//nSplitter的缺省值为5 bje'Oolc
//default value of nSplitter is 5 z30=ay1
this("","","",5); /CbkqNV
} .C6gl]6y@
<9T [yg
X!m;uJZp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oR77`
{ u$\Tg3du2
sSiteURL= sURL; ~O8]3+U
sFilePath = sPath; y^3,X_0
sFileName = sName; R4yJ.f
this.nSplitter = nSpiltter; -^0KE/
=qan%=0"h
Of!|,2`(
} 7;~2e
oUCVd}wH
:%pw`b, =V
public String getSSiteURL() [&fWF~D-p<
{ =g1D;
return sSiteURL; 1/!nV
} Qve`k<Cj"
K:C+/O
b\H/-7<
public void setSSiteURL(String value) /oBK&r[(
{ H_v/}DEG
sSiteURL = value; gr[D!D>
} i;gw=Be
-g~iE]x6Y
2~+'vi
public String getSFilePath() MuN[U17FB
{ +h9`I/R
return sFilePath; MV7}
} S".owe$\
YstXNN4
bl6':m+
public void setSFilePath(String value) CRP7U
{ [@jp9D H
sFilePath = value; @b4b{d5[
} zR_9D}
^o,y5,
m21QN9(i%
public String getSFileName() l[:^TfB
{ VNr!|bp5
return sFileName; 4c~*hMry
} 1V#B]x:
rAtai}Lx
w}fqs/)w
public void setSFileName(String value) "~B~{ _<j
{ ^Jc$BMaVg
sFileName = value; &?&'"c{;m
} MAl{66
3ZLr"O1l)
DX7Ou%P,mg
public int getNSplitter() 8s\8`2=
{ x A@|I#
return nSplitter; =lw4 H_
} 9_I[o.q
o<9yaQ;
_gis+f/8h
public void setNSplitter(int nCount) 2&3eAJC
{ yOn H&Jj
nSplitter = nCount; 3^uL`ETm@
} ;2+FgOj
} 9CgXc5
r! cNc
vy>];!Cu
/* +ytT)S
**Utility.java 3uB=L7.
*/ ^d5gz0d
package NetFox; vY8WqG]
^' edE5
T9&,v<f
public class Utility { zzDNWPzsA
e)fJd*P
A?%XO %
public Utility() TW;|G'}$
{ `Pz!SJ|
5pN08+
Off: ~
} E1mI Xd;.
BZnp #}f
//线程睡眠 N>uZt2
public static void sleep(int nSecond) b7F3]W<`&
{ U)IsTk~}O
try{ 7zz(#
Thread.sleep(nSecond); mH7CgI
} (@N~ j&
catch(Exception e) f z/?=
{ MZ >0K
e.printStackTrace (); g~i''lng
} ?(|TP^
} $Sc08ro
`Lb _J
//日志 `&"H* Ie
public static void log(String sMsg) *;V2_fWJ@
{ K{`2jK#
System.err.println(sMsg); S]#=ES'^/
} Cz$Hk;3\6
jSOa
q_%w l5\F
public static void log(int sMsg) Y'+F0IZ+
{ 8xeun~e"vS
System.err.println(sMsg); *R9mgv[
} X7imUy'.
} tOlzOBzR
9phD5b~j
9>}(]T
/* !Ed<xG/
**TestMethod.java *cb D&R\
*/ (<AM+|
package NetFox; { 8|Z}?I
5Fl
H8=vQy
public class TestMethod { /(WX!EEsB
}AeE|RNc
Npg5Z%+y
public TestMethod() 0N} wD-
{ ///xx/weblogic60b2_win.exe hoSU`X
try{ }y-AoG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8m13M5r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l yLK$B?/
SiteFileFetch fileFetch = new SiteFileFetch(bean); s K$Sar
fileFetch.start(); D3ZT''
} gw}7%U`T9
catch(Exception e){e.printStackTrace ();} zN729wK
{) '" k6w
^0,&R\e+
} )oz-<zW
sL[(cX?;2
j_YZ(: =
public static void main(String[] args) 5D02%U2N)G
{ G3^n_]Jb
new TestMethod(); 2=UTH%1D
} j)lM:vXR
} xVwi }jtG|
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