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)); /^ *GoB
} 3 d $
for(int i=0;i<nEndPos.length-1;i++) _%^t[4)q
{ \)Jv4U\;
nEndPos = nStartPos[i+1]; &* GwA
} {];4
nEndPos[nEndPos.length-1] = nFileLength; oz $T.
} juOOD
} jusP aAdW
h<;kj#qbb
nn>< k"
//启动子线程 R-nC+)^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uMOm<kn
for(int i=0;i<nStartPos.length;i++) %SORs(4
{ 7 +A-S9P)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )P4#P2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vfew )]I
nStartPos,nEndPos,i); @gzm4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3l5rUjRwj
fileSplitterFetch.start(); #;cDPBv*wS
} ]=ar&1}J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .C=&`;Vs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3&i8C,u]/O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kcT?<r
nEndPos = " + nFileLength); \%\b*OO
// fileSplitterFetch[nPos.length-1].start(); 4 4%jz-m
k#"Pv"
5<Mht6"H
//等待子线程结束 _\yrR.HIa
//int count = 0; q@ !p
//是否结束while循环 lsmzy_gV7
boolean breakWhile = false; R:=C
+SCUS]
<<F#Al
while(!bStop) H{|a+
{ ;-84cpfu
write_nPos(); N,v4SIC@
Utility.sleep(500); *;A I0
breakWhile = true; Q]X0O10
XvBEC_xWZ
"h.}o DS
for(int i=0;i<nStartPos.length;i++) ^$3 ~;/|
{ ;:xOW$
if(!fileSplitterFetch.bDownOver) Y ON@G5^
{ mY"DYYR>
breakWhile = false; ]P/eg$u'I
break; xh[4d
} i(.c<e{v~
} YbZ<=ZzO4
if(breakWhile) T=7V+
break; 8>q:Q<BB2
]PdpC"
Ycb<'M*jE
//count++; TSu^.K
//if(count>4) 4f,D3e%T|
// siteStop(); ]e+IaZ[Wo
} oiAU}iK:
pJ7wd~wF*
B.fLgQK0
System.err.println("文件下载结束！"); FxOhF03\=[
} Bu?"b=B*
catch(Exception e){e.printStackTrace ();} DJgk"'
} Gjuc"JR7
AfvTStwr
?QO)b9
//获得文件长度 Re?sopg0r
public long getFileSize() 20gPx;
{ YN4P >d
int nFileLength = -1; 2cfzLW(
try{ ]7kq@o/7
URL url = new URL(siteInfoBean.getSSiteURL()); ;cZ9C 1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jeb<qi>
httpConnection.setRequestProperty("User-Agent","NetFox"); F=
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|7WzTz
int responseCode=httpConnection.getResponseCode(); &|<~J(L;
if(responseCode>=400) .UbmU^y|
{ vj0`[X
processErrorCode(responseCode); j}8IT
return -2; //-2 represent access is error /1++ 8=
} gUDd2T#
EVmQ"PKL'
%z! w-u+
String sHeader; K/oPfD]
'T[=Uuj"
q|2{W.P5qi
for(int i=1;;i++) ;}IF'ANA
{ 1DcYc-k#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y>!9P\Xe
//Utility.log(in.readLine()); #m 3WZ3t$
sHeader=httpConnection.getHeaderFieldKey(i); "d'xT/l "
if(sHeader!=null) yZI4%fen
{ G1B~?i2$ ?
if(sHeader.equals("Content-Length")) G~)jk+Qq
{ 'ntb.S)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); en7i})v\".
break; ] d| -r:4
} :YjOv
} Tp~yn
else ]>E9v&X0
break; eG# (9
} d%9I*Qo0,
} sAk~`(:4!
catch(IOException e){e.printStackTrace ();} '.~vN L+ O
catch(Exception e){e.printStackTrace ();} YU76(S9 0#
BieII$\P%P
{d(PH7R
Utility.log(nFileLength); +`f gn9p
.}ZX~k&P
*Q=-7am
return nFileLength; F']Vg31c
} Hk2@X(
(o^V[zV
4M(w<f\5F
//保存下载信息（文件指针位置） F~a5yW:R=)
private void write_nPos() O|,+@qtH
{ Fhn883
try{ ?>q=Nf^Q.
output = new DataOutputStream(new FileOutputStream(tmpFile)); A4';((OXy
output.writeInt(nStartPos.length); V]H<:UE
for(int i=0;i<nStartPos.length;i++) 23+6u{
{ SrK;b .
// output.writeLong(nPos); doc5;?6
output.writeLong(fileSplitterFetch.nStartPos); fFXs:(
output.writeLong(fileSplitterFetch.nEndPos); ~2@U85"o
} K *vNv4
output.close(); /Re1QS
} UkNC|#l)
catch(IOException e){e.printStackTrace ();} H#U{i
catch(Exception e){e.printStackTrace ();} i40r}?-
} &:]_a?|*S
ABhza|
voQ,K9
//读取保存的下载信息（文件指针位置） oBqP^uT>a|
private void read_nPos() Fh v)
{ :;0?;dpO
try{ Vu`dEvL?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tP!sOvQ:
int nCount = input.readInt(); +KFK..
nStartPos = new long[nCount]; aSHZR
nEndPos = new long[nCount]; y#AY+ >
for(int i=0;i<nStartPos.length;i++) U YUIpe
{ .NjdkHYR
nStartPos = input.readLong(); ec1g7w-n
nEndPos = input.readLong(); 4EB$e?
} q(.%f3(
input.close(); `H/HLCt
} Cy6[p
catch(IOException e){e.printStackTrace ();} 6El%T]^
catch(Exception e){e.printStackTrace ();} =q xcM+OX1
} e7#=F6
u.hnQsM
=5Q;quKu^5
private void processErrorCode(int nErrorCode) (!X:[Ah*$
{ u6r-{[W}
System.err.println("Error Code : " + nErrorCode); fY%Sw7ql<
} NBMY1Xgj
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4vqu(w8 L
//停止文件下载 R<UjhCvx.
public void siteStop() aE{b65'Dt
{ "6KOql3
bStop = true; Cc Ni8Wg_
for(int i=0;i<nStartPos.length;i++) sef!hS06
fileSplitterFetch.splitterStop(); 't)j
fE7WLV2I>
8-?n<h%8E
} dJ24J+9}]j
} ixKQh};5/
//负责部分文件的抓取 4zf#zJw
**FileSplitterFetch.java H8\{GGg
*/ fI$,?>
package NetFox; |?8CV\D!
gX(QRQ
v?LJ_>hw*T
import java.io.*; }_?7k0EZ@
import java.net.*; BMX x(W]
&OzJ^G\o
M$&>"%Oi
public class FileSplitterFetch extends Thread { :cynZab
'!1lK
p$9N}}/c
String sURL; //File URL ~o # NOfYi
long nStartPos; //File Snippet Start Position .{x5(bi0S
long nEndPos; //File Snippet End Position P{>T?-Hj
int nThreadID; //Thread's ID ?q,x?`|(8
boolean bDownOver = false; //Downing is over WLh_b)V|
boolean bStop = false; //Stop identical LoCxoAg
FileAccessI fileAccessI = null; //File Access interface "R9kF-
N@d4)
in+`zfUJ9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {?L}qV
{ JK_$A;Q
this.sURL = sURL; &P+cTN9)
this.nStartPos = nStart; 4P:vo$Cy
this.nEndPos = nEnd; Sr+1.77}
nThreadID = id; =)I{KT:y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O/-OW: 03
} +M.|D,wg2
rW6w1
*v5y]E%aW
public void run() a9qZI
{ g)p[A 4
while(nStartPos < nEndPos && !bStop) %##9.Xm6l
{ 1^W Aps
Hd2_Cg FB
s~63JDy"E
try{ 5rcno.~QO
URL url = new URL(sURL); 92tb`'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [R:O'AP}@}
httpConnection.setRequestProperty("User-Agent","NetFox"); ix/uV)]k`
String sProperty = "bytes="+nStartPos+"-"; ftH 0aI
httpConnection.setRequestProperty("RANGE",sProperty); *l9Y]hinq
Utility.log(sProperty); oNh .Zgg
R1m18GHQ
,}|V'y
InputStream input = httpConnection.getInputStream(); ?<}qx`+%Q
//logResponseHead(httpConnection); .ZJh-cd
e| l?NXRX
j68Gz5;j
byte[] b = new byte[1024]; hs*:!&E
int nRead; {Y/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 02+^rqIx5
{ r-0 7!A
nStartPos += fileAccessI.write(b,0,nRead); 1%:A9%O)t
//if(nThreadID == 1) gSv<.fD"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $N ]P#g?Q
} W ][IHy<
p,0 \NUC
7yj2we
Utility.log("Thread " + nThreadID + " is over!"); G^OSXf5
bDownOver = true; =1JRu[&]8
//nPos = fileAccessI.write (b,0,nRead); o._^
} So 5{E4[
catch(Exception e){e.printStackTrace ();} c~C W-%wN
} i'u;"ot=
} 7xcYM
qqAsh]Z
!3&}r
//打印回应的头信息 h}d7M55#|
public void logResponseHead(HttpURLConnection con) G?g7G,|d
{ Z:OO|x
for(int i=1;;i++) KWYG\#S0]
{ ^49moC-
String header=con.getHeaderFieldKey(i); 8]L.E
if(header!=null) R.QcXz?d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Eg:p_F*lr
Utility.log(header+" : "+con.getHeaderField(header)); Y\=:j7'
else (Zn\S*_@/
break; %2+]3h>g
} @rF\6I
} u`~{:V
GhT7:_r~
th<]L<BP/
public void splitterStop() CNz[@6-cYU
{ ;wF|.^_2
bStop = true; yUG5'<lX
} $5o<Mj
/l`XJs
?|/}~nj7
} f:SF&t*
}:irjeI,
|)_R bqZ
/* %xruPWT:k
**FileAccess.java &Y>u2OZ
*//文件访问(定位，写) -$q/7,os
package NetFox; |{nI.>
import java.io.*; LKZI@i)
}X?*o`sW
R;yAqr29
public class FileAccessI implements Serializable{ 4tU~ ^z
Y[DKj!v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,+RO 5n
RandomAccessFile oSavedFile; 1L|(:m+
long nPos; ? `KOW
w;(gi
{|%O)fr,
public FileAccessI() throws IOException Dfo9jYPf
{ 8GP}g?%
this("",0); ( A)wcB
} ChGM7uu2
gK(4<PO'
!O-+h0Z
public FileAccessI(String sName,long nPos) throws IOException @FV;5M:I
{ .g~@e_;):
oSavedFile = new RandomAccessFile(sName,"rw"); a\w|tf
this.nPos = nPos; \2,18E
oSavedFile.seek(nPos); C] w< &o
} 6~S0t1/t?
ihWz/qx&q
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public synchronized int write(byte[] b,int nStart,int nLen) %},gE[N!J
{ o;mIu#u
int n = -1; o0L#39`'g
try{ * 2%e.d3"M
oSavedFile.write(b,nStart,nLen); Uz|]}t5V
n = nLen; \7/_+)0}'
} G= cxc_9
catch(IOException e) {1%ZyY
{ >B
e.printStackTrace (); d@tr]v5 B
} `[CJtd2\
<3}l8Z
f zO8by
return n; -#6*T,f0P(
} )mdNvb[*n
t] wM_]+
m-RY{DO+
} Ji[g@#
g-FZel
Ak Tw?v'
/* H\mVK!](D
**SiteInfoBean.java %#9~V
*/ YkPt*?,P/
package NetFox; dO,05?q|
63S1ed[
RHVv}N0
public class SiteInfoBean { '.yWL
6sl<Z=E#
VWy:U#;+8
private String sSiteURL; //Site's URL lg>AWTW[
private String sFilePath; //Saved File's Path lM*O+k
private String sFileName; //Saved File's Name 2H[aY%1T
private int nSplitter; //Count of Splited Downloading File =7fh1XnW
xUi!|c
QJWES%m`
public SiteInfoBean() 9Oyi:2A
{//nSplitter的缺省值为5 ]4mj 1g&C
//default value of nSplitter is 5 ->I{ :#
this("","","",5); I%919
} 3 ?F@jEQk
>-lL-%N_
H$amt^|zQ4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X&.$/xaT
{ p,\bez
sSiteURL= sURL; {K4t8T]
sFilePath = sPath; [E (M(w':
sFileName = sName; X-#mv|3
this.nSplitter = nSpiltter; JK"uj%
.oj"ru
43=-pyp
} ?]D+H%3[$i
o%PoSZZ
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public String getSSiteURL() So%1RY{)
{ G@EjWZQ
return sSiteURL; sFCs_u1tNN
} j :Jdwf
E)wT+\
zl 0^EltiU
public void setSSiteURL(String value) ;n{j,HB
{ s4`*0_n
sSiteURL = value; |/=p
} n UCk0:{
YCBML!L
rqe_zyc&
public String getSFilePath() 6XL9 qb~X
{ >ha Ixs`9
return sFilePath; zMzf=~
} b%f2"e0g
1=5'R/k
w^E]N
public void setSFilePath(String value) GdeR#%z
{ 4*XP;`
sFilePath = value; A|_%'8
} [I<'E LX
MQH8Q$5D
O\F^@;]F6
public String getSFileName() 0*IY%=i
{ :'rZZeb'
return sFileName; bA^:p3
} n[:AV
Q0uO49sg
pD_eo6xX
public void setSFileName(String value) |DPpp/
{ _&Uo|T
sFileName = value; 2]RH)W86;
} IcA\3j
9g5{3N3
%%,hR'+|
public int getNSplitter() '`~(Fkj
{ `{Di*
return nSplitter; p9}c6{Wp
} |XA aKZA
t2%@py*bU
2X;0z$
public void setNSplitter(int nCount) y#Za|nt
{ JS7}K)A2B6
nSplitter = nCount; ($ B]9*
} [xs)u3b
} QRZTT qG
9Glfi@.
IfmIX+t?
/* 9Bvn>+_K
**Utility.java q{Ta?|x#
*/ :f !=_^}
package NetFox; @uM3iO7&
k#:@fH4{PA
Hs`#{W{.
public class Utility { !_z<W~t"
/Zeg\}/4[
zmfRZ!Eh
public Utility() %)hIpxOrX
{ Or#+E2%1E
# /,2MQ
# pjyhH@
} ic{.#R.BY
+yP[(b/
//线程睡眠 8&A|)ur4
public static void sleep(int nSecond) 3|'#n[3
{ JXRf4QmG
try{ (zw=qbS&
Thread.sleep(nSecond); "G-0iKW;
} k E#_Pc
catch(Exception e) L[D/#0qp
{ Rr;LV<q+
e.printStackTrace (); vD)A)
} <.7I8B7
} #nf%ojh
QOh w
//日志 mLk6!&zN
public static void log(String sMsg) XAULD]Q
{ lF}$`6
System.err.println(sMsg); i h$@:^\
} vPl6Dasr
WVT5VJ7*
$6&GAJe
public static void log(int sMsg) z Jo#3
{ <E7Vbb9*
System.err.println(sMsg); .1z$ A
} J.e8UQ@=5
} D@rn@N
! N"L`RWD
g"dZB2`C
/* \l=KWa3Q
**TestMethod.java Q1ABnacR
*/ }2BH_ 2
package NetFox; [>M*_1F
[,o5QH\Etq
9*TS90>a
public class TestMethod { ox\B3U%`p}
&W)+8N,L
[;IDTo!<>
public TestMethod() hDD~,/yVxs
{ ///xx/weblogic60b2_win.exe y5AXL5
try{ +%le/Pg@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %M;_(jda
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Er0o{iI
SiteFileFetch fileFetch = new SiteFileFetch(bean); e2-70UvW^
fileFetch.start(); (9YYv+GGd*
} |<$<L`xoe
catch(Exception e){e.printStackTrace ();} O2'bNR
B )1<`nJA
msqxPC^I
} 8W1K3[Jj<
.y;\puNq
9OQ0Yc!3
public static void main(String[] args) kP}hUrDX5
{ Fyh?4!/.
new TestMethod(); T)Zt'M
} |?fW!y
} CNpe8M=/3
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