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)); vq0M[Vy
} Za:BJ:
for(int i=0;i<nEndPos.length-1;i++) 4na4Jsq{
{ #o"HD6e
nEndPos = nStartPos[i+1]; TJw.e/
} >nIcFm
nEndPos[nEndPos.length-1] = nFileLength; L1Cn
} +{Jf]"KD
} tls6rto
0ZID @^
XM@-Y&c$A
//启动子线程 .f92^lu9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }_kI>
for(int i=0;i<nStartPos.length;i++) 5k%N<e``
{ y8~)/)l&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6rN5Xf cS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }'.Sn{OWf
nStartPos,nEndPos,i); ^cmP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h$ETH1Ue
fileSplitterFetch.start(); Ay"2W%([`
} B> "r-O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,~N+?k_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [;CqvD<S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kG;\i
nEndPos = " + nFileLength); G|G?h
// fileSplitterFetch[nPos.length-1].start(); v/TlXxfil
ik:)-GV;s
ux79"5qb
//等待子线程结束 u.L8tR:(
//int count = 0; ! ^*;c#
//是否结束while循环 v$Y1+Ep9
boolean breakWhile = false; !K^kKP*l
Mevyj;1t
Pl5NHVr
while(!bStop) Uo[5V|>X6
{ '3_B1iAv
write_nPos(); = a.n`3`Q
Utility.sleep(500); %]sEt{
breakWhile = true; ]BQWA
:V-}Sde
}zS&H-8K
for(int i=0;i<nStartPos.length;i++) %qjyk=z+Z
{ seV;f^-hR
if(!fileSplitterFetch.bDownOver) :qSi>KCGh
{ )|^<woli,
breakWhile = false; 5wFS.!xD
break; 4FHX#`
} f({-j%m
} ]I' xLh`
if(breakWhile) \PMKmJX0O
break; > %cWTC
]Y: W[p
%K7EF_%
//count++; v/00LR
//if(count>4) X3=Jp'p$h
// siteStop(); Lz>{FOR
} I^\bS
bb:|1D
`J,~hK
System.err.println("文件下载结束！"); /'=^^%&:B
} -^xKG'uth
catch(Exception e){e.printStackTrace ();} J!fc)h
} =#")G1A
'SD|ObBY
Y <i}"eI*
//获得文件长度 -MW(={#
public long getFileSize() ' /<b[
{ 4k2c mM$
int nFileLength = -1; yb.|7U?/x
try{ <QW1fE
URL url = new URL(siteInfoBean.getSSiteURL()); "O1*uwm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6p]R)K>wS
httpConnection.setRequestProperty("User-Agent","NetFox"); 79B`w #
|`;1p@w"
(xSi6EZ6;
int responseCode=httpConnection.getResponseCode(); 8qYGlew,
if(responseCode>=400) %b%<g%@i
{ f`]E]5?
processErrorCode(responseCode); (kNTXhAr4
return -2; //-2 represent access is error qjEWk."
} 2l/5i]Tq
2#A9D.- h
3k[<4-
String sHeader; -5_xI)i
<9.7gwzE
+:Q/<^Z
for(int i=1;;i++) I 3,e)Z
{ DoB3_=yJ+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MG5Sn*(C
//Utility.log(in.readLine()); W]Tt8
sHeader=httpConnection.getHeaderFieldKey(i); XoQk'7"f
if(sHeader!=null) P<JkRX
{ ^5 =E`q".
if(sHeader.equals("Content-Length")) $JSC+o(q3#
{ QZa#iL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P7.8tM2}
break; Bsk2&17z
} o^"3C1j
} 0?;Hmq3
else [T#a1!
break; xI\s9_"Qy
} Y^m=_*1g5
} d47:2Zj
catch(IOException e){e.printStackTrace ();} +C;#Qf
catch(Exception e){e.printStackTrace ();} svRaU7<UDN
R$&&kmJ
|laKntv2
Utility.log(nFileLength); XoiYtx53
/F}\V ^
?CZD^>6
return nFileLength; :ItW|
} 2bxMIr
H;Qn?^
uW'4 Kt
//保存下载信息（文件指针位置） QuRg(K%:
private void write_nPos() ^(JbJ@m/
{ <Jrb"H[T"
try{ =&/a\z!
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4S EC4yO
output.writeInt(nStartPos.length); RGuHXf
for(int i=0;i<nStartPos.length;i++) 3U.qN0]
{ )j|y.[
// output.writeLong(nPos); i/Lq2n3 )
output.writeLong(fileSplitterFetch.nStartPos); <$2zr4
output.writeLong(fileSplitterFetch.nEndPos); LP6FSo~K
} 5@A=, GPUn
output.close(); RW^v{'o
} `'.x*MNF
catch(IOException e){e.printStackTrace ();} CvWEXY_P2
catch(Exception e){e.printStackTrace ();} 7kpW1tjY
} :bDn.`KG#
NKhR%H
m$qC 8z]
//读取保存的下载信息（文件指针位置） U`_vF~el~
private void read_nPos() Vzm+Ew _
{ 5GL+j%7
try{ R:^?6f<Z}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gO!h<1!
int nCount = input.readInt(); tsVhPo]e0
nStartPos = new long[nCount]; ioCkPj
nEndPos = new long[nCount]; @W- f{V
for(int i=0;i<nStartPos.length;i++) W2Z]?l;vQQ
{ B{(l5B6
nStartPos = input.readLong(); Y[?Wt/O;
nEndPos = input.readLong(); )qXe`3d5
} (w B[ ]O$@
input.close(); A@AGu#W
} lA 0_I"b2Y
catch(IOException e){e.printStackTrace ();} JlGD.!`
catch(Exception e){e.printStackTrace ();} gF5EtdN?|
} V46[whL%r
&7u Ra1/R
#h|< >
private void processErrorCode(int nErrorCode) yOzKux8kB
{ yP]W\W'
System.err.println("Error Code : " + nErrorCode); R3`W#`
} x#mk[SV
IjAity.Xrq
zNJyF;3
//停止文件下载 ulo7d1OVkJ
public void siteStop() =PM#eu
{ l%~zj,ew
bStop = true; _'p;V[(+M
for(int i=0;i<nStartPos.length;i++) !$#4D&T
fileSplitterFetch.splitterStop(); 7/!C
$_5v^QL
4aKy]zPoE
} ZM`_P!G
} <qt%MM [Y
//负责部分文件的抓取 )pa|uH+N
**FileSplitterFetch.java 1*b%C"C
*/ S`@*zQ
package NetFox; bA,D]
ofCP>Z-
%'O(Y{$Y.
import java.io.*; /2cOZ1G;
import java.net.*; KL~sEli
P~Owvs/=
`Db}q^mQ
public class FileSplitterFetch extends Thread { kO4~N-&
;0q6 bp(<H
x^BBK'
String sURL; //File URL 0M-AIQ5
long nStartPos; //File Snippet Start Position S-|$sV^cG
long nEndPos; //File Snippet End Position _lqAxWH
int nThreadID; //Thread's ID <sOB j'
boolean bDownOver = false; //Downing is over CZ}tQx5ga
boolean bStop = false; //Stop identical K\Q 1/})
FileAccessI fileAccessI = null; //File Access interface c7wgjQ[
R.;59s
a9-;8`fCR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DR8dJ#
{ <:-&yDh u
this.sURL = sURL; !iqz 4E
this.nStartPos = nStart; ,#Y".23G
this.nEndPos = nEnd; (6'Hzl^Kp
nThreadID = id; wX;NU4)n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P'k39
} Wfy+7$14M
iJeT+}
}clNXtN
public void run() 5]+eLKXB
{ &>{L"{
while(nStartPos < nEndPos && !bStop) | 'G$}]H
{ v}@6"\
GssoT<Y)Z
zv@o-R$l
try{ o\[nGf C&
URL url = new URL(sURL); `#F>?g$2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uESHTX/[
httpConnection.setRequestProperty("User-Agent","NetFox"); n1h+`nsf
String sProperty = "bytes="+nStartPos+"-"; rD?o97
httpConnection.setRequestProperty("RANGE",sProperty); ]A[~2]
Utility.log(sProperty); C?k4<B7V
m^KkS
?zqXHv#x
InputStream input = httpConnection.getInputStream(); Gr?gHAT
//logResponseHead(httpConnection); P6rL;_~e
S)?B I
m`aUz}Y>c
byte[] b = new byte[1024]; JG4I-\+H
int nRead; l[Oxf|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X3vrD{uNU
{ `h#JDcT;a
nStartPos += fileAccessI.write(b,0,nRead); .~']gih#
//if(nThreadID == 1) 2e&Zs%u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nor`w,2VF
} GEgf_C!%@
yMxS'j1
i8F~$6C
Utility.log("Thread " + nThreadID + " is over!"); ?jnEHn
bDownOver = true; x g@;d
//nPos = fileAccessI.write (b,0,nRead); .w&Z=YM
} ?##GY;#
catch(Exception e){e.printStackTrace ();} oT w1w
} O"GzeEY7
} ZN^Q!v
EBm\rM8
xgVt0=q
//打印回应的头信息 i7_BnJJX{B
public void logResponseHead(HttpURLConnection con) N]~q@x;<)3
{ NDi@x"];
for(int i=1;;i++) S5vJC-"
{ ]up:pddIh
String header=con.getHeaderFieldKey(i); }Na*jr0y9{
if(header!=null) qSR %#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yL1\V7GI{[
Utility.log(header+" : "+con.getHeaderField(header)); XUWza=BR"
else @EvnV.
break; h fNBWN
} qabM@+m[
} eZHi6v)i
=Ur/v'm
~W4<M:R
public void splitterStop() q4E{?
{ 3D3K:K!FK
bStop = true; )xU70:X
} G[<iVt$y
<W1!n$V ]
hH~Z hB
} SVJ3!1B,
*|cvx:GO
pn)5neX{
/* Sc(2c.HO*
**FileAccess.java u:k#1Nn!
*//文件访问(定位，写) Ty5\zxC|
package NetFox; i^(0,L
import java.io.*; U i;o/Z3
6Dch+*4*@
t}K?.To$
public class FileAccessI implements Serializable{ :98Pe6
h^4oy^9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cCwT0O#d
RandomAccessFile oSavedFile; w% M0Mu
long nPos; DF#Ob( 1
8Og9P1jVh
}9'rTLM
public FileAccessI() throws IOException V%+KJ}S!Z
{ FD8aO?wvg
this("",0); E+_}8J .
} "8N]1q:$4
-?ip?[Z
yRAb HG,c
public FileAccessI(String sName,long nPos) throws IOException {3?g8e]zr
{ BZE19!
oSavedFile = new RandomAccessFile(sName,"rw"); NLj0\Pz|B
this.nPos = nPos; Z#0z#M`
oSavedFile.seek(nPos); e3[N#ryt
} 'tOo0Zgc
Pai{?<zGi
VF4F7'
public synchronized int write(byte[] b,int nStart,int nLen) n1v%S"^
{ ,}bC
int n = -1; 45#`R%3
try{ w>#~_x,`
oSavedFile.write(b,nStart,nLen); +Q{jV^IT9
n = nLen; -Q,lUP
} 5dhRuc
catch(IOException e) F3?v&
{ V&gUxS]*
e.printStackTrace (); :Y"f.>
} z19y>j
+* &!u=%G
Ly3^zFW
return n; )y8$-"D(it
} 1w35H9\g
q4VOK 'N
LJT+tb?K
} =oSv=xY
@o8\`G
.L8S_Mz
/* H -`7T;t~
**SiteInfoBean.java DS^PHk39
*/ hD;[}8qN{
package NetFox; |d8/ZD
Iu%S><'+
CFVe0!\
public class SiteInfoBean { &a O3N
#[2]B8NZ
b"p,~{
private String sSiteURL; //Site's URL 7Rq;V=2YV
private String sFilePath; //Saved File's Path ($]y*|Obn
private String sFileName; //Saved File's Name 9NVe>\s_
private int nSplitter; //Count of Splited Downloading File fAJQ8nb{@]
'9-8_;
1Ocyrn
public SiteInfoBean() 5gi`&t`
{//nSplitter的缺省值为5 Wh"oL;O
//default value of nSplitter is 5 !\CoJ.5=
this("","","",5); ^;N+"oq!y
} e1K,4Bq
8JGt|,
)Nk^;[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MOdodyG
{ 3:!+B=woR
sSiteURL= sURL; \6*3&p
sFilePath = sPath; nx=Zl:Q}
sFileName = sName; 3nxJ`W5j
this.nSplitter = nSpiltter; Hw_(Af?C
Wl}d6ZTm
~c+0SuJ
} J v'$6[?
z6$W@-Vd
[|e7oNT(Q
public String getSSiteURL() {p+7QlgK
{ Lylw('zZ
return sSiteURL; C;M.dd
} nxCwg>
rk{DrbRx
<1>\?$)D
public void setSSiteURL(String value) yX?& K}JI
{ RD<l<+C^~
sSiteURL = value; UuW"
} Ydh]EO0'
h0L*8P`t
[<7Hy,xr_
public String getSFilePath() ?u"MsnCXYn
{ tGe|@.!
return sFilePath; g!i\AMG?
} BJwPSKL
t=Tu-2,k
]HCu tq
public void setSFilePath(String value) zaf%%
{ (pNA8i%=G
sFilePath = value; =EgiV<6vcH
} C|8.$s<
J[du>1D
s9?klJg
public String getSFileName() H"6Sj-<=
{ w-pdpbHV
return sFileName; 1^TOTY
} ojni+}>_
G BV]7.
KpA iKe
public void setSFileName(String value) E80C0Q+V
{ ^ 1}_VB)^
sFileName = value; y4^6I$M7V
} -$!`8[fM
zVFz}kJa
O|}97a^
public int getNSplitter() sFqZ@t}~
{ be}^}w=
return nSplitter; LzEs_B=9
} 9l5l"Wj&
Zu951+&`
F 0q#.
public void setNSplitter(int nCount) ,dOd3y'y
{ OQIQ
nSplitter = nCount; `}Ssc-A
} b`)^Ao:
} 5B)Z@-x2
<05\
WLqwntzk
/* ),1MR=
**Utility.java df;-E
*/ qc;9{$?xV
package NetFox; 481J=8H
1A^~gYr
Ke@zS9
public class Utility { G'T/I\tB
(P&~PJH
:yO.Te F
public Utility() ]U.1z
{ zBg>I=hiG
#&a-m,Y$sx
D^V0kC p!F
} E(N?.i-%$
Vw0cf;
//线程睡眠 d#6'dKV$
public static void sleep(int nSecond) gIa/sD2m>
{ ]NgK(IU
try{ sJu^deX
Thread.sleep(nSecond); X;25G
} MM8@0t'E
catch(Exception e) #Ux*":
{ "5Orj*{
e.printStackTrace (); Qvo(2(
} 4Rj;lAlwB
} *;b.x"
m!{Xuy
//日志 F/GfEMSE
public static void log(String sMsg) U"\$k&
{ v%N/mL+5L
System.err.println(sMsg); H6i4>U*
} 9ReH@5_bGM
baJ(Iy$XT
49. @Uzo
public static void log(int sMsg) i Lr*W#E
{ *9V;;bY#
System.err.println(sMsg); HRP4"#9R
} V}<Hx3!
} F|.,lb |L
Q(Q.(
::bK{yZm
/* []B9Me
**TestMethod.java &+F|v(|r
*/ ;e~Z:;AR
package NetFox; 5cLq6[uO
2p'ujAK
ACQbw)tiv}
public class TestMethod { ' *hy!f]
29eg.E
d#~^)r
public TestMethod() Z#H] yG
{ ///xx/weblogic60b2_win.exe -)
try{ cTpmklq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); llG^+*Y8t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a3}#lY):
SiteFileFetch fileFetch = new SiteFileFetch(bean); zQY|=4NP
fileFetch.start(); o#(z*v@
} #XSs.i{
catch(Exception e){e.printStackTrace ();} YbS$D
/JaCbT?*T
0XwDk$l<
} r8PXdNg
Z:F5cXt<
G55-{y9Q
public static void main(String[] args) _"BYnPq@wb
{ V?KACYd@O
new TestMethod(); lgR;V]^YX
} j9)WInYc:
} 9OIX5$,S;
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