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)); jm/`iXnMf
} `1fY)d^ZS
for(int i=0;i<nEndPos.length-1;i++) _)m]_eS._
{ 0 /U{p,r6`
nEndPos = nStartPos[i+1]; Kis"L(C
} yWo; a
nEndPos[nEndPos.length-1] = nFileLength; I1M%J@Cz
} VjZ|$k
} `b7t4d*
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S_UIO.K
//启动子线程 . 3T3EX|G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ( ^Nz9{
for(int i=0;i<nStartPos.length;i++) 5<Nx^D
{ =m#?neop
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `+:`_4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &d^m 1
nStartPos,nEndPos,i); S;#'M![8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =dYqS[kJW
fileSplitterFetch.start(); k,+0u/I
} "J_9WUN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >_T-u<E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s9DYi~/,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g*C7 '
nEndPos = " + nFileLength); tl^9WG
// fileSplitterFetch[nPos.length-1].start(); }Oq5tC@$G
r52gn(,
6mxfLlZ
//等待子线程结束 00~mOK;1
//int count = 0; ~V1E0qdAE
//是否结束while循环 }N6.Uu5zI
boolean breakWhile = false; `7V]y-
56kI 5:
kJT)r6
while(!bStop) =MDysb&:
{ ],Do6 @M-
write_nPos(); P{lB50
Utility.sleep(500); sWnLEw
breakWhile = true; ;+hH
v;D~Pa
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for(int i=0;i<nStartPos.length;i++) =$JET<(
{ s R/F"
if(!fileSplitterFetch.bDownOver) ')<hON44EX
{ '!~)?C<
breakWhile = false; 7n<::k\lb
break; r0% D58
} *#+An<iT ;
} z[qDkL
if(breakWhile) |#R7wnE[k~
break; ^9:Z7 >Z
59;KQ
pB0 \\wR
//count++; ^WWQI+pk
//if(count>4) &7tbI5na@
// siteStop(); vy:Z/1q
} &E5g3lf
>7DhTM-A
5vnrA'BhBU
System.err.println("文件下载结束！"); 4zFW-yy
} @?]RBX?a
catch(Exception e){e.printStackTrace ();} 5#E`=C%
} &`2)V;t
8$Y9ORs4
$X,D(
//获得文件长度 (V2fRv
public long getFileSize() f x+/C8GK
{ iSs:oH3l
int nFileLength = -1; ri-b=|h2j
try{ 1\I}2;
URL url = new URL(siteInfoBean.getSSiteURL()); q9s=~d7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jij*x>K>y
httpConnection.setRequestProperty("User-Agent","NetFox"); T</F 0su|
6?c7$Y
p9{mS7R9T
int responseCode=httpConnection.getResponseCode(); )MTOU47U
if(responseCode>=400) 89(Q1R ?:
{ &\*(Q*2N
processErrorCode(responseCode); d5:c^`
return -2; //-2 represent access is error IF:;`r@%
} "oO%`:pb
v"Es*-{B
U z>+2m(
String sHeader; s|r3Gv|G
^.QzQ1=D
k~1?VQ+?M
for(int i=1;;i++) #!+:!_45
{ 3L}A3de'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {&1/V
//Utility.log(in.readLine()); PB\x3pV!}
sHeader=httpConnection.getHeaderFieldKey(i); u.xnOcOH!
if(sHeader!=null) ?m"( Soh
{ 1#+S+g@#
if(sHeader.equals("Content-Length")) ^s"R$?;h
{ -PR N:'T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r3UUlR/Do
break; 1/J=uH
} 9~[Y-cpoi
} I9ep`X6Y
else &gx%b*;`L0
break; ER.}CM6{[
} k@W1-D?
} U&p${IcEm
catch(IOException e){e.printStackTrace ();} nb%6X82Q
catch(Exception e){e.printStackTrace ();} [MY|T<q
aAUvlb
=Jb>x#Y
Utility.log(nFileLength); %n9aaoD
RPRBmb940
Z/+#pWBI!
return nFileLength; 6(ol1 (U
} oYH-wQj
JZyAXm%
$*fMR,~t&
//保存下载信息（文件指针位置） l!u_"I8j5
private void write_nPos() 7hPY_W y
{ zy }$i?
try{ sd|).;s}
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1p=]hC
output.writeInt(nStartPos.length); qY!Zt_Be6
for(int i=0;i<nStartPos.length;i++) eehb1L2(b
{ 5$C-9
// output.writeLong(nPos); 11;MN
output.writeLong(fileSplitterFetch.nStartPos); #AQV(;r7@
output.writeLong(fileSplitterFetch.nEndPos); A~70
} $qj2w"'
output.close(); I b5rqU\
} E~"y$Fqe
catch(IOException e){e.printStackTrace ();} o?\?@H
catch(Exception e){e.printStackTrace ();} /%io+94
} tY4;F\e2|A
~Z'?LV<t
fI|Nc
//读取保存的下载信息（文件指针位置） d7bS wL
private void read_nPos() i=2N;sAl
{ R4:b{)=O
try{ 3(80:@|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f4|rVP|x
int nCount = input.readInt(); qUb&
nStartPos = new long[nCount]; t"oeQ*d%
nEndPos = new long[nCount]; I-l_TpM)
for(int i=0;i<nStartPos.length;i++) &{t,'[ u
{ hp|YE'uYT
nStartPos = input.readLong(); I%KYtv~`
nEndPos = input.readLong(); e+fN6v5pU
} ?%[jR=w
input.close(); ?4T-@~~*`=
} ysY*k`5
catch(IOException e){e.printStackTrace ();} lL0APT;
catch(Exception e){e.printStackTrace ();} IJcsmNWm
} \qJXF|z<K
x7 ,5
|P?*5xPB
private void processErrorCode(int nErrorCode) `r 3
{ .(k|wX[Fu~
System.err.println("Error Code : " + nErrorCode); %d9uTm;
} >i?oC^QM
S3Jo>jXS "
@`9]F7h5W
//停止文件下载 (TT}6j
public void siteStop() .HABNPNg(
{ +ami?#Sz*;
bStop = true; "E4a=YH_
for(int i=0;i<nStartPos.length;i++) [ub e6
fileSplitterFetch.splitterStop(); KF:78C
7WzxA=*#
)zDCu`
} g*+>H1}
} O*P.]d
//负责部分文件的抓取 $VOFOc
**FileSplitterFetch.java xr^LFn)
*/ 5wU]!bxr
package NetFox; 8P\Zo8}v
W ]8QM1$
j8:\%|
import java.io.*; J\=*#*rJ1
import java.net.*; kvu)y`
((%?`y
S)"Jf?
public class FileSplitterFetch extends Thread { )MT}+ai
{(Es(Sb}c
k)TpnH! "
String sURL; //File URL XfIJ4ZM5
long nStartPos; //File Snippet Start Position Ar#(psU
long nEndPos; //File Snippet End Position B/Ws_Kv
int nThreadID; //Thread's ID b4Ekqas
boolean bDownOver = false; //Downing is over 6[AL|d DK
boolean bStop = false; //Stop identical KLk~Y0$:v
FileAccessI fileAccessI = null; //File Access interface N?`' /e
!ULn7\@
:e+jU5;]3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <<O$ G7c
{ *wjrR1#81x
this.sURL = sURL; w7&A0M
this.nStartPos = nStart; k$:|-_(w
this.nEndPos = nEnd; C\hM =%
nThreadID = id; TIg3`Fon
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B^}yo65I
} {R{=+2K!|k
_Y m2/3!
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public void run() j3ls3H&
{ 0jWVp-y
while(nStartPos < nEndPos && !bStop) 4E}Yt$|
{ -m#)B~)
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lPAQ3t!,
try{ SSzIih@u
URL url = new URL(sURL); :\_ 5oVb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qn2&nD%zi
httpConnection.setRequestProperty("User-Agent","NetFox"); buHJB*?9
String sProperty = "bytes="+nStartPos+"-"; $3kH~3{]
httpConnection.setRequestProperty("RANGE",sProperty); 7F~X,Dk_
Utility.log(sProperty); 9} .z;prz
es0hm2HT3
sV*H`N')S
InputStream input = httpConnection.getInputStream(); wVtwx0|1
//logResponseHead(httpConnection); )0k53-h&
}c:M^Ff
3Tm+g2w2V8
byte[] b = new byte[1024]; d2L&Z_}
int nRead; I)HPO,7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3=V&K-
{ 'dc#F3
nStartPos += fileAccessI.write(b,0,nRead); 1Ai^cf:S
//if(nThreadID == 1) e]$s t?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o^wqFX(Y
} tfWS)y7
>/6 _ ^
bW+:C5'
Utility.log("Thread " + nThreadID + " is over!"); "d}Gp9+$VY
bDownOver = true; GTxk%
//nPos = fileAccessI.write (b,0,nRead); )=(kBWM
} M869MDo
catch(Exception e){e.printStackTrace ();} G^@5H/)
} M)(DZ}
} Z4bNV?OH
bvOq5Q6
+ >!;i6|
//打印回应的头信息 b\,+f n
public void logResponseHead(HttpURLConnection con) tX~w{|k
{ /dIzY0<aO
for(int i=1;;i++) dDGQ`+H9
{ ]eV8b*d6
String header=con.getHeaderFieldKey(i); K:WDl;8(d
if(header!=null) 62NsJ<#>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b#o|6HkW
Utility.log(header+" : "+con.getHeaderField(header)); ]/{)bpu
else :rP=t ,
break; Zj Z^_X3
} iU:cW=W|M\
} ?\n> AC
z'7]h TA
y>ktcuML
public void splitterStop() )O6>*wq
{ V]?R>qhgu
bStop = true; l}P=/#</T
} 3__-nV
/zox$p$?h
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} wdoR%b{M
qxJ\ye+'*
dD@(z:5M\
/* J9 I:Q<;
**FileAccess.java *=xr-!MEk
*//文件访问(定位，写) _','9|
package NetFox; *OQ2ucC8j
import java.io.*; - ! S_ryL
f)<6
Kf-JcBsrT
public class FileAccessI implements Serializable{ h>bx}$q
(QiAisE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O.JN ENZf
RandomAccessFile oSavedFile; UL9n-M=
long nPos; ,]/X\t5]D
TJ*T:?>e
\^1E4C\":
public FileAccessI() throws IOException . 'yCw#f
{ $`'/+x"%
this("",0); M'l ;:
} >5 BJ3Hf
#,v{Ihn
Z #m+ObHK1
public FileAccessI(String sName,long nPos) throws IOException .o}v#W+st
{ wS3'?PRX
oSavedFile = new RandomAccessFile(sName,"rw"); a09<!0Rp
this.nPos = nPos; y~HP>~Oh
oSavedFile.seek(nPos); #Rr%:\*
} `wU!`\
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\.}c9*)
public synchronized int write(byte[] b,int nStart,int nLen) 9MqGIOQ${j
{ NyuQMU
int n = -1; 7>*vI7O0l
try{ Vf1^4t
oSavedFile.write(b,nStart,nLen); EB|}fz
n = nLen; >`D:-huNeE
} ?Ss!e$jf
catch(IOException e) ]J]h#ZHx
{ {(?4!rh
e.printStackTrace (); pmYHUj #
} !Xw5<J3L-
(C)p9-,
|sZHUf_
return n; f|oh.z_R
} f`66h M[
)BfAw
z([</D?
} mXs; b 2r^
Mrb)
<QGXy=
/* _h1mF<\ X^
**SiteInfoBean.java S$XSei_q
*/ _GPl gp:
package NetFox; kg\>k2h
J9S>yLQK
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public class SiteInfoBean { o3}3p]S\
}SCM I4\
)}O8?d`
private String sSiteURL; //Site's URL w@fi{H(R
private String sFilePath; //Saved File's Path (&x['IR
private String sFileName; //Saved File's Name .6 ?U@2
private int nSplitter; //Count of Splited Downloading File LjHVJSC
vY`s'%WV
Ny)X+2Ae
public SiteInfoBean() C+&l< fM&
{//nSplitter的缺省值为5 Eu04e N
//default value of nSplitter is 5 seeBS/%
this("","","",5); ~4cC/"q$X
} {H'Y `+
o*hF<D$Y
FHI ;)wn=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ENY+^7
{ BTrn0
sSiteURL= sURL; ,UE83j8D^
sFilePath = sPath; )dd@\n$6
sFileName = sName; %D "I
this.nSplitter = nSpiltter; aC)!T
8, >P
63B?.
} Aq7osU1B
0_t!T'jr7
b>JDH1)
public String getSSiteURL() qJUK_6|3
{ NQ2E
return sSiteURL; D.XvG_
} $L]lHji
~61v5@
~W]TD@w
public void setSSiteURL(String value) P7/X|M z
{ FaJ&GOM,
sSiteURL = value; 5l*&>C[(i
} G,w(d@
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VY\&8n}e(
public String getSFilePath() SasJic2M
{ )53y AyP
return sFilePath; du^J2m{f
} 65^9
_:27]K:
x-3\Ls[I
public void setSFilePath(String value) <2qr}K{'A
{ Hj,A5#|=J
sFilePath = value; P7~>mm+
} :9 ^* ^T
kMd.h[X~
Q]>.b%s[
public String getSFileName() 1&Zj
{ ~&bq0(
return sFileName; B^9j@3Ux
} czd~8WgOa
u;c?d!E
h'F=YF$o
public void setSFileName(String value) |Xy6PN8
{ 4{`{WI{
sFileName = value; =rX>.P%Q5
} #;nYg?d=
'`KY!]L
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public int getNSplitter() V~5jfcd
{ aw42oLk
return nSplitter; }`~+]9<
} ^J;bso`
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?5 7Sk+
public void setNSplitter(int nCount) %bfQ$a:
{ <UQbt N-B\
nSplitter = nCount; '."ed%=MC
} 3$9W%3
} w+CA1q<
n7-6- #
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/* B`J~^+`[*
**Utility.java {{p7 3 'u
*/ X}\:_/
package NetFox; 3/n5#&c\4
Jze:[MYS
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public class Utility { 9-*uPK]m9
"LTad`]<Ro
s!7y
public Utility() k+pr \d~
{ p=}Nn(
65Yv4pNL
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} ?<'}r7D
#4 pB@_
//线程睡眠 hQDXlFHT
public static void sleep(int nSecond) r\V ={p
{ U\*J9
try{ AkQ~k0i}b
Thread.sleep(nSecond); !d0kV,F:
} 7O-x<P;
catch(Exception e) _zi|
{ WEi2=3dV
e.printStackTrace (); 0Z{ZO*rK
} ~FG]wNgS
} :X (=z;B;N
G*P#]eO
//日志 ^3L0w}#
public static void log(String sMsg) SKsKPqz
{ ,1o FPa{?
System.err.println(sMsg); uk<9&{
} A{D];pE`
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?2Py_gkf
public static void log(int sMsg) wEvVL
{ P me^l%M
System.err.println(sMsg); <B6H. P =
} @QPz#-
} M:B=\&.O
338k?nHxv
n8ZZ#}Nhg
/* q'Tf,a
**TestMethod.java '@k+4y9q?
*/ X?qK0fS
package NetFox; +OWX'~fd<
'kO!^6=4M
lp%pbx43s
public class TestMethod { ZeaA%y67U
~%kkeh\j
P:MT*ra*,
public TestMethod() t=W}SH
{ ///xx/weblogic60b2_win.exe mSl.mi(JiZ
try{ Trz@~d/[,n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +}os&[S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UhQj Qaa~
SiteFileFetch fileFetch = new SiteFileFetch(bean); UJ')I`zuI
fileFetch.start(); A@{PZ
} PP33i@G
catch(Exception e){e.printStackTrace ();} @YTaSz$L
9 X`Sm}i
fN1-d&T
} LIF7/$,0
)W _v:?A9
68C%B9.b'
public static void main(String[] args) |"CZT#
{ 5(Q%XQV*P
new TestMethod(); y,,dCca
} PmEsN&YP]
} 4yA+h2
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