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)); O3o^%0
} Xs052c|s
for(int i=0;i<nEndPos.length-1;i++) metn&
{ mxgT}L0i
nEndPos = nStartPos[i+1]; i#*[, P~
} KBB)xez8
nEndPos[nEndPos.length-1] = nFileLength; LRu,_2"
} r89AX{:
} /&Oo)OB;
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i;1pw_K
//启动子线程 @FN|=?8%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nKm# kb
for(int i=0;i<nStartPos.length;i++) p [C 9g
{ 0 MK}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (&SU)Uvu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~6t!)QATnp
nStartPos,nEndPos,i); W94:%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %jjPs.
fileSplitterFetch.start(); e&z@yy$
} fY&TI}Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #!F>cez
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xA Ez1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S<i1t[E@W
nEndPos = " + nFileLength); IQO|)53)
// fileSplitterFetch[nPos.length-1].start(); >g{&Qx`&
Ih:Q}V#6
dzOco)y
//等待子线程结束 kku<0<(N
//int count = 0; JI.=y5I
//是否结束while循环 _s5^\~ao
boolean breakWhile = false; }"TQ\v$
[ *Dj:A)V^
r5~W/eE
while(!bStop) @bA5uY!
{ -fPiHKJ
write_nPos(); 3UUdJh<~
Utility.sleep(500); ^yPZ$Q
breakWhile = true; !{^kH;*u
VBL4cU8D
wmGcXBHt$
for(int i=0;i<nStartPos.length;i++) h_(M#gG
{ Wz'!stcp
if(!fileSplitterFetch.bDownOver) @G2# Z
{ 0beP7}$
breakWhile = false; .m]}Ba}J$
break; > mO*.'Gm
} pRun5 )7
} 4tCM2it%
if(breakWhile) Vr},+Rj
break; !4afU:
csW\Q][
9s"st\u 4
//count++; <9,h!
//if(count>4) MG vz-E1e
// siteStop(); )7*'r@
} cK1^jH<|
7G_<+rn
J| N 6r
System.err.println("文件下载结束！"); "M5
} CImp,k0
catch(Exception e){e.printStackTrace ();} 8Ij<t{Lps
} QZ&(e2z
[cnuK
Br9j)1;
//获得文件长度 <Ja&z M
public long getFileSize() 3l<qcKKc
{ ?\8aT"o
int nFileLength = -1; [<53_2]~
try{ Eto"B"
URL url = new URL(siteInfoBean.getSSiteURL()); YAc:QVT87
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <ZSXOh,'
httpConnection.setRequestProperty("User-Agent","NetFox"); L4Jm8sy{
jcqUY+T$
M]PZwW8
int responseCode=httpConnection.getResponseCode(); `TJhH<z"%
if(responseCode>=400) ^nPy(Q0
{ Hq}g1?b
processErrorCode(responseCode); /.0K#J:
return -2; //-2 represent access is error mzK0$y#*o
} i-wRwl4aEF
!-}Q{<2@W
'l^Bb#)"
String sHeader; t?>}0\1
+H3~Infr4f
`;}`>!8j
for(int i=1;;i++) B`-uZ9k
{ Sn*s@RE\s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "?zWCH
//Utility.log(in.readLine()); zjr($?
sHeader=httpConnection.getHeaderFieldKey(i); "a[;{s{{.
if(sHeader!=null) qIuo8o}
{ 3`reXms*{
if(sHeader.equals("Content-Length")) u9f^wn
{ v<v;ZR)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }3: mn
break; Nl YFS?5
} *:H,-@
} <)TIj6
else qkhre3
break; {'4#{zmp
} eWDXV-xD
} uNn1qV
catch(IOException e){e.printStackTrace ();} :o^ioX.J
catch(Exception e){e.printStackTrace ();} nCi ]6;Y
W5Z-s.o
n'mrLZw
Utility.log(nFileLength); SEI0G_wk$
o>M^&)Xs
myA;Y
return nFileLength; e^eJ!~0
} t}R!i-D|HB
xH2'PEjFM
r7W.}n*
//保存下载信息（文件指针位置） l!:bNMd
private void write_nPos() #k9&OS?
{ tM"vIz 05
try{ dQIF'==6
output = new DataOutputStream(new FileOutputStream(tmpFile)); d=bKNA90
output.writeInt(nStartPos.length); Oz%6y ri
for(int i=0;i<nStartPos.length;i++) #|E#Rkw!
{ 6ZIPe~`
// output.writeLong(nPos); A>gZl)c
output.writeLong(fileSplitterFetch.nStartPos); S Q:H2vvD
output.writeLong(fileSplitterFetch.nEndPos); "J,|),Yd
} ouCh2Y/_
output.close(); y0p=E^QM
} M@es8\&S.
catch(IOException e){e.printStackTrace ();} X>7Pqn'
catch(Exception e){e.printStackTrace ();} bji#ID2]%
} {oY"CZ2
7=N%$]DKZ
4C?{p%3c
//读取保存的下载信息（文件指针位置） M%_*vD
private void read_nPos() !f(A9V
{ ]@9W19=P!P
try{ PWS8Dpb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); liYsUmjZ=
int nCount = input.readInt(); Vw w 211
nStartPos = new long[nCount]; Kq")|9=d
nEndPos = new long[nCount]; 'G65zz
for(int i=0;i<nStartPos.length;i++) dsw^$R}
{ ?M'CTz}<\
nStartPos = input.readLong(); wm#(\dj
nEndPos = input.readLong(); -I{op wd
} JYNnzgd
input.close(); #tZ!D^GQHq
} 6%p6BK6
catch(IOException e){e.printStackTrace ();} ?:/J8s [O
catch(Exception e){e.printStackTrace ();} ]uFJ~:R
} Gs"lmX-{$j
|rJN
W2XWb<QSEV
private void processErrorCode(int nErrorCode) :a Cf@:']
{ yI8O#
System.err.println("Error Code : " + nErrorCode); TkTGYh
} fASklcQ
{s@!N
Ydsnu
//停止文件下载 Q#yHH]U)X
public void siteStop() 1^o})9
{ 2n>mISy+
bStop = true; }2LG9B%
for(int i=0;i<nStartPos.length;i++) fV4eGIR&
fileSplitterFetch.splitterStop(); vULDKJNHX
xKL(:ePS
C4E}.``Hm
} aT2%Az@j
} <P1nfH
//负责部分文件的抓取 R5b,/>^'A
**FileSplitterFetch.java pqs!kSJV
*/ uD{-a$6z
package NetFox; ;PMPXN'z6
%62|dhl6
^4WZ%J#g
import java.io.*; A?HDY_u
import java.net.*; #vK99S2
EIzTbW{p
ISZEP8w
public class FileSplitterFetch extends Thread { ^Vth;!o
t@lTA>;U@
" AvEo
String sURL; //File URL rYPuo
long nStartPos; //File Snippet Start Position n.N0Nhd
long nEndPos; //File Snippet End Position sifjmNP
int nThreadID; //Thread's ID &56\@t^
boolean bDownOver = false; //Downing is over 9Q(Lnu
boolean bStop = false; //Stop identical zz3{+1w]
FileAccessI fileAccessI = null; //File Access interface vB7]L9=@"
w`boQ_Ir
Y_$!XIJ4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )LG!"~qiz
{ )5`^@zx
this.sURL = sURL; zLr:zfl
this.nStartPos = nStart; ~yN>9fU
this.nEndPos = nEnd; b6e2a/x
nThreadID = id; HHyN\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g[b;1$
} pPsTgGai
`Q+O#l?
hHMp=8J7
public void run() X..M!3W
{ hT=E~|O
while(nStartPos < nEndPos && !bStop) O:V.;q2]U
{ *W |
Q.4+"JoG
7zQGuGo(
try{ D@w&[IF
URL url = new URL(sURL); /FTP8XHwL)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mtFC H
httpConnection.setRequestProperty("User-Agent","NetFox"); meB9:w[m
String sProperty = "bytes="+nStartPos+"-"; #?M[Q:
httpConnection.setRequestProperty("RANGE",sProperty); p/ZgzHyF
Utility.log(sProperty); Y]&2E/oc
A\/DAVnI
IwXQbJ3v_
InputStream input = httpConnection.getInputStream(); )q!dMZ(
//logResponseHead(httpConnection); vG}\Amx+
sWA-_4
\HoVS
byte[] b = new byte[1024]; N}z]OvnZH
int nRead; N^`S'FVA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9@h-q(-
{ V?MaI.gj
nStartPos += fileAccessI.write(b,0,nRead); 0^P9)<k'
//if(nThreadID == 1) A@.ruG$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?)qm=mebY
} 5 a&a-(
Jk<b#SZ[b
v>hc\H1P
Utility.log("Thread " + nThreadID + " is over!"); hsws7sH
bDownOver = true; JDpW7OrDc
//nPos = fileAccessI.write (b,0,nRead); #)DDQ?D
} ayf;'1
catch(Exception e){e.printStackTrace ();} q|B.@Ng.
} $f"Ce,f
} _}H`(d%N
<aMihT)dd
's8LrO(=
//打印回应的头信息 d8jP@>
public void logResponseHead(HttpURLConnection con) j}%C;;MPH
{ c@O7,y:`I
for(int i=1;;i++) O[}2
{ >\Iy <M
String header=con.getHeaderFieldKey(i); Em<J{`k6
if(header!=null) XC[AJ!q`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BYI13jMH+Y
Utility.log(header+" : "+con.getHeaderField(header)); _A$V~Hp9q
else 7bW''J*6
break; dr=KoAIxy
} .GDY J9vi
} nzi)4"3O
:=`N2D
=5p?4/4 J
public void splitterStop() hG/Z65`&
{ |msQ
bStop = true; dBL{Mbh2Z
} o[G,~f\-
P-N+
U,2\ TBz
} 44hz,
40LAG
B&lF! ]
/* }PzYt~Z`@
**FileAccess.java =H^^AG\}
*//文件访问(定位，写) mhnK{M @56
package NetFox; W-"FRTI4
import java.io.*; P4"EvdV7
}'TZ)=t{J
75H5{#)
public class FileAccessI implements Serializable{ A$'rT|>se
9TE-'R@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7w|4BRL
RandomAccessFile oSavedFile; FU(s jB
long nPos; #w]:<R^
ZsDn`8
#kEa&Se
public FileAccessI() throws IOException VV~Kgy
{ 7G8M+i3q/
this("",0); 8!dA1]2;
} ^p7Er!
e,0Gc-X[B
dzc.s8T(0
public FileAccessI(String sName,long nPos) throws IOException 5zII4ukn*
{ b"#|0d0
oSavedFile = new RandomAccessFile(sName,"rw"); )x&}{k6 %
this.nPos = nPos; e0u*\b
oSavedFile.seek(nPos); $30lNZK1m8
} Y]1b39O
)e:u 6]
uJHf6Ye
public synchronized int write(byte[] b,int nStart,int nLen) >RT02Ey>
{ n&uD=-
int n = -1; @k2nID^>
try{ }3mIj<I1;
oSavedFile.write(b,nStart,nLen); ]2B=@V t,
n = nLen; a?9Ka!O4s
} >&N8Du*[
catch(IOException e) M&O .7B1}
{ w6l8RNRe
e.printStackTrace (); 1QH5<)Oa
} {wp"zaa
owc#RW9 7
;GxKPy
return n; '=vD!6=0@
} ng[ZM);
'Sjcm@ILm
~I)\d/7o
} Vg4N7i
6~0.YZ9
/\M3O
/* 0/JusQ
**SiteInfoBean.java :Keek-E`e=
*/ !pLQRnI}6
package NetFox; Li_ a|dI
x5}Ru0Z
3 aG?^z
public class SiteInfoBean { %t^-Guz
HGpj(U:`c
"(rG5z3P
private String sSiteURL; //Site's URL NrdbXPHceN
private String sFilePath; //Saved File's Path .DSmy\FI5
private String sFileName; //Saved File's Name {` Lem
private int nSplitter; //Count of Splited Downloading File %<w)#eV?
']ussFaQ
`PR)7}/<
public SiteInfoBean() aJ1<X8
{//nSplitter的缺省值为5 n089tt=TE
//default value of nSplitter is 5 !bG%@{WT
this("","","",5); />zE$)'M
} a:tCdnK/
jn9KQe\3
iWZrZ5l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V'4sOn
{ Q}M% \v
sSiteURL= sURL; r0)X]l7
sFilePath = sPath; \j]i"LpWb
sFileName = sName; }?=$?3W
this.nSplitter = nSpiltter; .* xaI+:
wh@;$s"B
SablF2doa
} BVX6
&i,xod6$
;X ]+r$_
public String getSSiteURL() dk9'C
{ }Q?,O
return sSiteURL; "-+5`!Y
} j\D_Z{m2
|BGQ|7DyG
hX~d1.]Y
public void setSSiteURL(String value) y pv~F
{ OFTyN^([@
sSiteURL = value; }Zue?!KQ
} I|*w?i*
Oozt&* F
YULI y-W
public String getSFilePath() 0m^(|=N-
{ #%xzy@`
return sFilePath; ew#t4~hh
} WCc,RI0
%># VhK
%(IkUD
public void setSFilePath(String value) 9"3 7va
{ YzqUOMAt"V
sFilePath = value; I65W^b4y
} gUs.D_*
0?KY9
ua%$r[
public String getSFileName() SM2QF
{ P\B ]><!ep
return sFileName; p^~AbU'6~
} qcSlY&6+
JgJ4RmH-
0HA`
public void setSFileName(String value) eot]VO:
{ g?.ls{H
sFileName = value; 3?F*|E_
} XjL)WgQ{i
dBKL_'@@}
pPSmSWD?
public int getNSplitter() Lj"@JF;c
{ t%$>
return nSplitter; ]uN}n;`12
} r%*,pN7O
uz6S7I
Tji G!W8
public void setNSplitter(int nCount) qU(,q/l
{ YL_M=h>P
nSplitter = nCount; |N%?7PZ(
} fz[o;GTc
} ]o18oY(
#"J8]3\F
3":vjDq$
/* U_t[J|
**Utility.java .tv'`
*/ /gWaxR*m
package NetFox; 6;WfsG5
uHj"nd13
OT[&a6_
public class Utility { o}q>oa b z
+{(f@,&~{
ZS*PY,
public Utility() ,%>]
{ @N,(82k
?RyeZKf
&M p??{g
} 5G!0Yy['
>/@wht4- j
//线程睡眠 Ah5`Cnv
public static void sleep(int nSecond) -][~_Hd{
{ SvZ~xTit
try{ ^O#>LbM"x
Thread.sleep(nSecond); M3m!u[6|
} N~rA/B]T
catch(Exception e) 0!<qfT a
{ TR;"&'#k
e.printStackTrace (); or~2r8
} }HB>Zb5
} 3q'["SS
{kCCpU
//日志 a_jw4"Sb
public static void log(String sMsg) |\/`YRg>
{ gEghDO_G
System.err.println(sMsg); 00jWs@K
} Q&j-a;L
g=)B+SY'
%b8ig1
public static void log(int sMsg) 7+_TdDBYs
{ }q<p;4<\F
System.err.println(sMsg); 0&M~lJ
} `fTH"l1zn
} "Y%fk/v8
'%Cc!63t*
S#h-X(4
/* ~ _ ogeD
**TestMethod.java 2/XrorV
*/ ''t\J^+&
package NetFox; bSa%?laS
} Xbmb8
%rE:5)
public class TestMethod { tuT>,BbR
k P]'
3jSt&+
public TestMethod() I+08tXO
{ ///xx/weblogic60b2_win.exe pco:]3BF6
try{ G>siyUh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sfD@lW3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SvTd#>ke
SiteFileFetch fileFetch = new SiteFileFetch(bean); #mT\B[4h
fileFetch.start(); .r ,wc*SF
} Pz\4#E]
catch(Exception e){e.printStackTrace ();} (G1KMy
8jBrD1
@:,B /B;
} f.yvKi.Cm
k^VL{z:EWB
,> Ya%;h2k
public static void main(String[] args) zR@4Z>6
{ azhilUD8
new TestMethod(); \#50; 8VJ
} ~F [V
} [TX1\*W
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