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)); }9=VhC%J
} Bg{"{poy
for(int i=0;i<nEndPos.length-1;i++) *Mk5*_
{ NvY%sx,
nEndPos = nStartPos[i+1]; MqRpG5 .
} KFx4"f%
nEndPos[nEndPos.length-1] = nFileLength; "{Lp'+wNw
} Eu2@%2}P
} q&#f#Ou
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f!AcBfaLr
//启动子线程 =c:K(N qL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1$H*E~
for(int i=0;i<nStartPos.length;i++) Z$"E|nRN
{ qX>mOW^gT8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ')zdI]@M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d?)k<!fJk
nStartPos,nEndPos,i); 8tJB/Pw`S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0CX2dk"UB^
fileSplitterFetch.start(); K 0R<a~
} ?hHVawt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {oOzXc6o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hV_bm@f/y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %|Sh|\6A!
nEndPos = " + nFileLength); lcO;3CrJ!
// fileSplitterFetch[nPos.length-1].start(); k <SFl
8cI<~|4_
A%(t'z
//等待子线程结束 &?59{B.mD
//int count = 0; :(ni/,~Q
//是否结束while循环 TL'^@Y7X5
boolean breakWhile = false; g$+ $@~
j6}/pe*;;T
[TRHcz n
while(!bStop) |L wn<y
{ ?> )(;Ir9
write_nPos(); u)J&3Ah%
Utility.sleep(500); GI']&{
breakWhile = true; v"-@'qN'
d|I?%LX0p
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for(int i=0;i<nStartPos.length;i++) iW oe
{ |T3F:],`
if(!fileSplitterFetch.bDownOver) m%7T ~
{ I8M^]+c
breakWhile = false; 7 G37V"''
break; 20h+^R3{Z
} II;
} <l>o6K
if(breakWhile) ?9W2wqN>o
break; J7a_a>Y
rW),xfo0
LlbRr.wL
//count++; 4}&$s
//if(count>4) D6z*J?3^#&
// siteStop(); $1KvL8
} cug=k
ey!QAEg"X1
M4rI]^lJ
System.err.println("文件下载结束！"); 5=@q!8a*
} K%i9S;~
catch(Exception e){e.printStackTrace ();} `YL)[t? V
} !I)wI~XF)5
#ATV#/hW
wB%N}bi!
//获得文件长度 d x52[W
public long getFileSize() +t[i68,%
{ <gfkbDP2
int nFileLength = -1; Lfr>y_i;F
try{ i?^lEqy[
URL url = new URL(siteInfoBean.getSSiteURL()); ?OD43y1rzd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]&+,`1_q
httpConnection.setRequestProperty("User-Agent","NetFox"); iC(&U YL
;cpQ[+$nKp
_98 %?0
int responseCode=httpConnection.getResponseCode(); +T!7jC(O Q
if(responseCode>=400) pA?kv]l(
{ Yl\p*j"Fid
processErrorCode(responseCode); .0=VQU
return -2; //-2 represent access is error mssCnr;
} 4C]>{osv
V;@kWE>3
qE:/~Q0
String sHeader; 8r{:di*
"fH"U1Bw
VUd=|$'J
for(int i=1;;i++) 9=o;I;I
{ ?hfyQhR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F4:giu ht
//Utility.log(in.readLine()); ^s.necg0
sHeader=httpConnection.getHeaderFieldKey(i); vXI2u;=y
if(sHeader!=null) {)KH%
{ "Qci+Qq
if(sHeader.equals("Content-Length")) FV~ENpncP
{ x%]5Q/|Ur
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3OZu v};k
break; _-6IB>
} 5yl[#>qt
} I_"KhBM
else "~+?xke5z
break; )Up'W
} u*"mdL2
} J}?:\y<
catch(IOException e){e.printStackTrace ();} QJ%[6S
catch(Exception e){e.printStackTrace ();} -h%!#g
a Byetc88/
9fhgCu]$
Utility.log(nFileLength); 8 o^ h\9I
| > t,1T.
]:g;S,{
return nFileLength; 09_5niaz[
} SW; %2
x )w6
0YsBAfRG
//保存下载信息（文件指针位置） nm}wdel"
private void write_nPos() @hVF}ybp
{ GeydVT-
try{ MGbl-,]
output = new DataOutputStream(new FileOutputStream(tmpFile)); T*3>LY+bb
output.writeInt(nStartPos.length); #Y>os3]
for(int i=0;i<nStartPos.length;i++) I7C*P~32{n
{ RX\l4H5;
// output.writeLong(nPos); 8n'"RaLQ8
output.writeLong(fileSplitterFetch.nStartPos); xtq='s8e
output.writeLong(fileSplitterFetch.nEndPos); ;}W-9=81
} a9%^Jvm"
output.close(); HAca'!p
} UB9n7L(@c
catch(IOException e){e.printStackTrace ();} _$vAitUe4S
catch(Exception e){e.printStackTrace ();} B&},W*p
} {vf4l4J(
^1 U<,<
OL0W'C9oA
//读取保存的下载信息（文件指针位置） ibj3i7G?
private void read_nPos() Ho!dtEs
{ \2U FJ
try{ k.@OFkX.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {9_}i#,vR
int nCount = input.readInt(); K.l7yBm
nStartPos = new long[nCount]; 552yzn1
nEndPos = new long[nCount]; }]BH "
for(int i=0;i<nStartPos.length;i++) +r<d z
{ I}hY @
nStartPos = input.readLong(); V;-$k@$b.
nEndPos = input.readLong(); 9\J6G8b>|I
} kKlcK_b;
input.close(); *= ;M',nx
} _X/`7!f
catch(IOException e){e.printStackTrace ();} 7FBaN7l
catch(Exception e){e.printStackTrace ();} r0'6\MS13
} HQ0fY
2Y-NxW^]
}j\_XaB
private void processErrorCode(int nErrorCode) y} W-OLE
{ jwQ(E
System.err.println("Error Code : " + nErrorCode); sc)}r_|g
} GB&^<@
B{6wf)[O
yd+.hg&J
//停止文件下载 +[_mSt
public void siteStop() PgMU|O7To
{ sCrOdJ6|
bStop = true; yzH[~O7
for(int i=0;i<nStartPos.length;i++) 8x/]H(J
fileSplitterFetch.splitterStop(); "> ]{t[Ib
xC}9W6
l.3|0lopX)
} IMT]!j&Y,
} ^Ee"w7XjD
//负责部分文件的抓取 p~bx
**FileSplitterFetch.java At$[&%}
*/ I|eYeJ3
package NetFox; m6 VL
edZhI
eWw# T^
import java.io.*; ;GF+0~5>
import java.net.*; o1^Rx5
uJ@C-/BD!M
_Gb O>'kE
public class FileSplitterFetch extends Thread { X={Z5Xxr"
w;=g$Bn
*%p`Jk-U
String sURL; //File URL JQ"R%g`8
long nStartPos; //File Snippet Start Position g\~n5=-D
long nEndPos; //File Snippet End Position DV5K)m&G
int nThreadID; //Thread's ID i[V\RKH*F
boolean bDownOver = false; //Downing is over hwj:$mR
boolean bStop = false; //Stop identical [PP&}.k4"
FileAccessI fileAccessI = null; //File Access interface tsf)+`vt
j.:I{!R#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fnZ?YzLI
{ 2Q81#i'Cm
this.sURL = sURL; F!*tE&Se+
this.nStartPos = nStart; tmVGJ+gz
this.nEndPos = nEnd; v3I-i|L<)
nThreadID = id; P g.j]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bh0hUE
} FzM<0FJRX
<Y"h2#M"
mR3-+dB/
public void run() 5!V%0EQqw
{ q>5K:5
while(nStartPos < nEndPos && !bStop) NO'37d
{ ^X\SwgD2w
Uz$.sa
=b_/_b$q
try{ QFX/x
URL url = new URL(sURL); (Rs052m1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K}a3Bj,
httpConnection.setRequestProperty("User-Agent","NetFox"); (@nEe?
String sProperty = "bytes="+nStartPos+"-"; 5SQqE@g%
httpConnection.setRequestProperty("RANGE",sProperty); :JD*uu
Utility.log(sProperty); _|f_%S8a_=
T6^H%;G
"fN=Y$G
InputStream input = httpConnection.getInputStream(); qS?uMms7w
//logResponseHead(httpConnection); `E:&a]ul
/kH 7I
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byte[] b = new byte[1024]; /c|X:F!;X#
int nRead; RTQtXv6mD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -F~"W@9r
{ 4uy:sCmu
nStartPos += fileAccessI.write(b,0,nRead); 9ymx;
//if(nThreadID == 1) !HCuae3_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =tQ^t4_
} 0/TP`3$X#"
D4IP$pAD
oUNuM%g9Dy
Utility.log("Thread " + nThreadID + " is over!"); Dhze2q)o
bDownOver = true; Ra)AQ n
//nPos = fileAccessI.write (b,0,nRead); _/[}PQC6G
} ~pWV[oUD
catch(Exception e){e.printStackTrace ();} PW QRy
} MiN|u
} C.N#y`g
LCMZw6p
<Gw>}/-^
//打印回应的头信息 A(}D76o_
public void logResponseHead(HttpURLConnection con) IlfH
{ 9YEE.=]T
for(int i=1;;i++) F9Co m}
{ r$WBEt,B
String header=con.getHeaderFieldKey(i); a1 v%G
if(header!=null) 'izv[{!n{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /|LQ?n
Utility.log(header+" : "+con.getHeaderField(header)); h\lyt(.s
else :D:Y-cG*n<
break; FXG,DJ:
} =x3T+)qCNX
} %}[/lIxaE
PFI^+';
&1Cif$Y4w
public void splitterStop() sDl@
{ 7?"-:q
bStop = true; zJH:`~GxE
} tb/`*Yl@
9(pF!}1%\
}P\J?8
} kHz?vVE/l
BG^)?_69
=k\Qx),Ir
/* y"Ios:v@-
**FileAccess.java oZ\zi> Y,
*//文件访问(定位，写) ]Wg&r Y0
package NetFox; z*e`2n#\
import java.io.*; ,{Ga7rH*
vWVQ8S.
pF<KhE*V
public class FileAccessI implements Serializable{ -58Sb"f
1qm _Qs&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {xu~Dx
RandomAccessFile oSavedFile; Pj^O8
long nPos; G]RFGwGt
d$B+xW
%0q)PT\
public FileAccessI() throws IOException }m93AL_y
{ w~ O)DhC
this("",0); nj=nSD
} v9MliD'
XM~eocn
iLk"lcX
public FileAccessI(String sName,long nPos) throws IOException r1a/'+
{ S N;1F
oSavedFile = new RandomAccessFile(sName,"rw"); vl>_;}W7
this.nPos = nPos; ks7id[~&iY
oSavedFile.seek(nPos); $E-c%-
} [B@R(z=H
2Q)pT$
8d[!"lL
public synchronized int write(byte[] b,int nStart,int nLen) Yv"-_
{ /E^j}H{
int n = -1; f{+X0Oj
try{ tvOyT6]
oSavedFile.write(b,nStart,nLen); %`0*KMO3
n = nLen; $g '4'
} [/Xc},HbMe
catch(IOException e) ZN}U^9m=
{ (".WJXB\
e.printStackTrace (); 8V@\$4@b!#
} C]M{
[[uZCKi
UUEbtZH;
return n; j"9Zaq_
} 1O+$"5H
l 9bg
PBb'`PV
} \OVw
:~\ y<
p!7(ayu
/* S4D~`"4$/
**SiteInfoBean.java 8X)1bNGqhe
*/ ,lQfsntk'
package NetFox; cB_3~=fV
9 =D13s(C
9d8U@=
public class SiteInfoBean { (|sqN8SbA
nmoC(| r
t'*2)U
private String sSiteURL; //Site's URL /_i]bM7W
private String sFilePath; //Saved File's Path $!K,5^+
private String sFileName; //Saved File's Name k(dNHT
private int nSplitter; //Count of Splited Downloading File \z?-
X!K:V~WG
#Ti5G"C
public SiteInfoBean() eb7~\|9l1i
{//nSplitter的缺省值为5 Hr/Q?7g
//default value of nSplitter is 5 `q+Ug
this("","","",5); 'J:xTp
} ?<~P)aVVj
M7c53fz
.83z =
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k@Bn}r
{ #R#|hw
sSiteURL= sURL; 9iN}v
sFilePath = sPath; 2o1 RJk9
sFileName = sName; @pV&{Vp
this.nSplitter = nSpiltter; jN{+$ @cI
zfK3$|
28O3N;a
} 79Q>t%rD[
\&4)['4,
G`NGt_C
public String getSSiteURL() #.|MV}6rQ
{ 7-c3^5gn{
return sSiteURL; X-_0wR
} yTh60U
+?uZ~VSl
5mg] su&#
public void setSSiteURL(String value) c{!XDiT]P
{ vf?m-wh
sSiteURL = value; XT\Q"=FD
} \"l/D?+Q
6mC% zXR5
V?4G~~F
public String getSFilePath() V#\iO
{ ^\FOMGai
return sFilePath; HfA@tZ5q|U
} kx07Ium
#RP7?yGM,
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public void setSFilePath(String value) 89[OaT_hs
{ g BV66L
sFilePath = value; 7r$'2">K(
} <26Jif:
q[TW
Q9sxI}D )R
public String getSFileName() \O+Hmi^
{ ux1SQ8C*
return sFileName; OB\jq!"
} JV;-P=o1B
e*pYlm
RhI>Ak;-
public void setSFileName(String value) ){"-J&@?
{ 7hl,dtn7
sFileName = value; ' O d_:]
} 6"|+\
Fes/8*-
HsAKz]Mq
public int getNSplitter() E(0[/N~
{ j/w*2+&v
return nSplitter; lU%L
} ]L9$JTGF`w
{KM5pK?,BJ
'L ]k\GO
public void setNSplitter(int nCount) H05U{vR
{ K6e_RzP,.w
nSplitter = nCount; mW_ N-z
} ;09U*S$eK
} gIcm`5+T
#B8V2_M
A`1-c
/* sNZOm$
**Utility.java y=zs6HaS
*/ "qoJIwl#q
package NetFox; .t.4y. 97
='6@^6y
wcW7k(+0
public class Utility { :PNhX2F
qRXHaQi@9
F]cc?r312
public Utility() VVqpzDoXG
{ oxLO[js
g ,yB^^%
,15$$3z/E
} zS'{F>w
7pM&))R
//线程睡眠 b6g/SIae
public static void sleep(int nSecond) WS"v"J%
{ WnhH]WY
try{ !}q@O-}j
Thread.sleep(nSecond); AmK g;9LS
} k#G+<7c<
catch(Exception e) ;}'Z2gZB
{ Q}uh`?t
e.printStackTrace (); wsgT`M'J[
} @B9#Hrc
} w:2yFC
]W7&ZpF
//日志 Si68_]:^
public static void log(String sMsg) n/^QPR$>.
{ aT8A+=K6
System.err.println(sMsg); 40$9./fe)
} S*%:ID|/C2
rd^j<
)2J#pz?.
public static void log(int sMsg) $x2G/5?
{ 0OBwe6*
System.err.println(sMsg); RQ,X0pS
} qWJap-hb
} {'cdi`
%:y"o_X_
d.k'\1o
/* j6Au<P
**TestMethod.java t![972.&
*/ 1pT/`x
package NetFox; 5;A=8bryU
;0}C2Cz'
vqo ~?9z[e
public class TestMethod { rLcXo%w
ZWx4/G
@}{Fw;,(7n
public TestMethod() ._<gc;G
{ ///xx/weblogic60b2_win.exe be'&tsZ9
try{ $it>*%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5K00z?kD2V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M] W5%3do
SiteFileFetch fileFetch = new SiteFileFetch(bean); '8b=4mrbH
fileFetch.start(); _#w5hXcu
} a]4|XJ_
catch(Exception e){e.printStackTrace ();} j2jUrl
uKo4nXVtp
mWuhXY^Q
} D1EHT}
t}gK)"g
u HXb=U
public static void main(String[] args) 6e;8\1^
{ -;$jo-
new TestMethod(); jyC>~}?
} sVP2$?
} CN7qqd
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