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)); k'K 1zUBj
} }Q_ }c9?
for(int i=0;i<nEndPos.length-1;i++) - S%8
{ n ZzGak
nEndPos = nStartPos[i+1]; S~{}jvc
} /?:q9Wy
nEndPos[nEndPos.length-1] = nFileLength; sB<y(}u
} 2bTM0-
} 3NrWt2?
i",oPz7
(Uk\O`)m
//启动子线程 ,h'omU7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vVH*\&H\T
for(int i=0;i<nStartPos.length;i++) 7@ mP;K0
{ rv%^2h<&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]dnB,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I(+%`{Wv
nStartPos,nEndPos,i); 3E;<aCG?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %F]:nk`
fileSplitterFetch.start(); fCi1JH;
} 0vcFX)]yW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wp//SV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \PK}4<x}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |$c~Jq
nEndPos = " + nFileLength); 6"La`}B(T8
// fileSplitterFetch[nPos.length-1].start(); 4z,n:>oH
+qmV|$rmM
j.UO>1{7
//等待子线程结束 ./}W3
//int count = 0; _Zbgmasb
//是否结束while循环 incUa;
boolean breakWhile = false; ASaNac-3
tN&X1
;h7O_|<%
while(!bStop) E^t}p[s
{ 2$?j'i!
write_nPos(); Ve4@^Jy;
Utility.sleep(500); +<n8O~h
breakWhile = true; pv,I_"
P>ZIP* Gr
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for(int i=0;i<nStartPos.length;i++) =%9j8wHX
{ 0/zgjT|fe
if(!fileSplitterFetch.bDownOver) 3 ~\S]
{ `6y\.6j
breakWhile = false; axdRV1+s
break; xMo'SpVz:
} ?4lDoP{
} B0:/7Ld$Ml
if(breakWhile) Ml9
break; J.n-4J#@
i UW.$1l
G0v<`/|>}
//count++; go5l<:9
//if(count>4) BY??X=
// siteStop(); HH'5kE0;d
} |1Pi`^
s F3M= uz
w-?Cg8bq<
System.err.println("文件下载结束！"); x-@6U
} ZVz`-hB
catch(Exception e){e.printStackTrace ();} f}+8m .g2
} D2Dk7//82Y
G:{\-R'
Mt+ggF.
//获得文件长度 \FjY;rqfKe
public long getFileSize() ;.b^A
{ (Kaunp5_`
int nFileLength = -1; K"9V8x3Wg
try{ y`-5/4
URL url = new URL(siteInfoBean.getSSiteURL()); CFiO+p&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F[==vte|
httpConnection.setRequestProperty("User-Agent","NetFox"); RTvzS]
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qn~:B7f
int responseCode=httpConnection.getResponseCode(); 5`[B:<E4
if(responseCode>=400) w1 tg7^(@
{ Q)}z$h55
processErrorCode(responseCode); 5tl uS
return -2; //-2 represent access is error HDT-f9%}<4
} D^\2a;[AxA
2V=bE-
"3:TrM$|A
String sHeader; ]$?\,`
f)!7/+9>
%R LGO&
for(int i=1;;i++) f2RIOL,
{ o:Q.XWa@MG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jd?NN:7
//Utility.log(in.readLine()); Af7&;8pM
sHeader=httpConnection.getHeaderFieldKey(i); HU+zzTgI
if(sHeader!=null) =CjN=FM
{ nwPU{4#l<
if(sHeader.equals("Content-Length")) UvM_~qo
{ dLy-J1h\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {]dH+J7
break; M[,G#GO
} z+6%Ya&ls
} DU1\K
else Gu@Znh-D
break; bdkxCt
} 1PjqXgN5p
} lF.yQ
catch(IOException e){e.printStackTrace ();} !0 -[}vvU
catch(Exception e){e.printStackTrace ();} '7TT4~F
d3K-|
Q!"W)tD
Utility.log(nFileLength); ,7|Wf %X
I6Mr[#*
UIi`bbJ
return nFileLength; mL[Y{t#N
} *IBCThj
k>q}: J9V
e&J_uG
//保存下载信息（文件指针位置） qI#ow_lL#
private void write_nPos() uV+.(sjH
{ %t<ba[9F
try{ UV8K$n<
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZMI vzQYI
output.writeInt(nStartPos.length); N"rZK/@}
for(int i=0;i<nStartPos.length;i++) dt|f4XWF
{ ~6-6aYhe
// output.writeLong(nPos); h`b[c.%
output.writeLong(fileSplitterFetch.nStartPos); *]RCfHo\=
output.writeLong(fileSplitterFetch.nEndPos); a#4 'X*
} SebJ}P1x
output.close(); N_),'2
} *oU-V#
catch(IOException e){e.printStackTrace ();} Y]>Qu f.!
catch(Exception e){e.printStackTrace ();} O)Mf/P'
} "/}cV5=Z
J{bNx8.&
#Bgq]6G2
//读取保存的下载信息（文件指针位置） _F9O4Q4
private void read_nPos() ,3E9H&@j
{ zS+_6s
try{ R x.]m0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {f<\`
int nCount = input.readInt(); K JX@?1"
nStartPos = new long[nCount]; e<[0H 8
nEndPos = new long[nCount]; OGqsQ
for(int i=0;i<nStartPos.length;i++) ,%%}d9
{ fK{[=xMr@
nStartPos = input.readLong(); JDy;Jb
nEndPos = input.readLong(); I~.d/!>Z
} b&1-tYV
input.close(); <m3or
} /)E'%/"A
catch(IOException e){e.printStackTrace ();} duk:: |{F
catch(Exception e){e.printStackTrace ();} KGoHn6jM
} l`A4)8Y@
Lb} cjI:
,dO$R.h
private void processErrorCode(int nErrorCode) )mbRG9P
{ XU19+mW=P
System.err.println("Error Code : " + nErrorCode); J%n{R60b
} SS/t8Y4W
SJdi*>
r9d dVD
//停止文件下载 t@O4!mFH
public void siteStop() 9M$N>[og
{ f8'$Mn,
bStop = true; $ZOKB9QccC
for(int i=0;i<nStartPos.length;i++) (66DKG
fileSplitterFetch.splitterStop(); 1KtPq,
(ATCP#lF
8K/o/
} mC}!;`$8p
} >7^+ag~&
//负责部分文件的抓取 r!7e:p JLO
**FileSplitterFetch.java /NDuAjp[@
*/ [Ifhh2
package NetFox; 8xEOR!\!`k
f;"6I
4fCg{
import java.io.*; -=A W. Zo
import java.net.*; ;dh8|ujh
\O7Vo<B&D
"<J%@
public class FileSplitterFetch extends Thread { 0u"/7OU
j{;RuNt
6Q6l?!|W4
String sURL; //File URL b88Zk*
long nStartPos; //File Snippet Start Position |_P-
long nEndPos; //File Snippet End Position .V\M/q\Tv
int nThreadID; //Thread's ID !dW77kLTg
boolean bDownOver = false; //Downing is over qJ|n73yn
boolean bStop = false; //Stop identical r4D6I,
FileAccessI fileAccessI = null; //File Access interface -MqWcB9&
C,!}WB@VME
E(&GZ QE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #Rkldv'
{ ) -C9W7?I
this.sURL = sURL; XI*_ti
this.nStartPos = nStart; C;jV{sb9c
this.nEndPos = nEnd; Q#i^<WUpg
nThreadID = id; _x.D< n=X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g}-Ch#
} XT|!XC!|
weOzs]uc
&z\]A,=Tc
public void run() ;|hEXd?b
{ -|DSfI#j
while(nStartPos < nEndPos && !bStop) @MV%&y*z.
{ PZdYkbj
epH48)2
yO6 _Gq{
try{ ^!*?vHx:
URL url = new URL(sURL); Z-{!Z;T)z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (&6C,O~n^.
httpConnection.setRequestProperty("User-Agent","NetFox"); /I'n]
String sProperty = "bytes="+nStartPos+"-"; Y,bw:vX
httpConnection.setRequestProperty("RANGE",sProperty); 9o7d3ir)
Utility.log(sProperty); #f'(8JjY
Y"uFlHN&i
Jb~-)n2
InputStream input = httpConnection.getInputStream(); E00zf3Jgv'
//logResponseHead(httpConnection); xmDX1sL**
Ohm>^N;
>q&Q4E0
byte[] b = new byte[1024]; (Jw[}&+
int nRead; !k&~|_$0@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [LonY49
{ axY-Vj
nStartPos += fileAccessI.write(b,0,nRead); ?[W(r$IaE
//if(nThreadID == 1) _e.b#{=9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~EU[?
} f$E66yG
~PNO|]8j
."Yub];H
Utility.log("Thread " + nThreadID + " is over!"); xrT_ro8
bDownOver = true; j}R4mh
//nPos = fileAccessI.write (b,0,nRead); JXlFo3<
} v`hv5wQ
catch(Exception e){e.printStackTrace ();} \ooqa<_
} Gc9^Z=
} ~^.&nph
6,xoxNoPP3
0<L@f=i
//打印回应的头信息 lO9{S=N
public void logResponseHead(HttpURLConnection con) g[;iVX^1&
{ \2<2&=h?
for(int i=1;;i++) =3=KoH/'
{ zJMKgw,i*
String header=con.getHeaderFieldKey(i); KrkZv$u,
if(header!=null) JXeqVKF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YF{K9M!
Utility.log(header+" : "+con.getHeaderField(header)); 2t { Cpw
else {K'SOhH4?
break; =tcPYYD
} Vk_*]wU
} |Z;wk&
$EJ*x$
|?Q(4(D`*
public void splitterStop() u,F d[[t
{ nRQIrUNq
bStop = true; xgR*j
} 7o z(hO~
Ut-6!kAm
>B~jPU
} *:.0c
i,")U)b
K23_1-mbe
/* p8"(z@T
**FileAccess.java "|DR"rr'j
*//文件访问(定位，写) RQ,(?I*8\
package NetFox; 8"LaP3U
import java.io.*; )O- x1U
%FFw!eVi
dr6 dK
public class FileAccessI implements Serializable{ o33{tUp'
+lha^){
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GIVs)~/Eq
RandomAccessFile oSavedFile; 8 (^2
long nPos; hqD;<:.
lO $M6l
0]oQ08
public FileAccessI() throws IOException 3R#<9O
{ W,{`)NWg
this("",0); ,f?#i%EF&
} Ql*/{#$
z3*G(,
=w A< F
public FileAccessI(String sName,long nPos) throws IOException 0v7;ZxD
{ 2K*-uT#$~
oSavedFile = new RandomAccessFile(sName,"rw"); nv$
this.nPos = nPos; )Elr8XLw
oSavedFile.seek(nPos); 9jPb-I-
} 2Bjp{)*
'fAD Dh}
a3c4#'c|D
public synchronized int write(byte[] b,int nStart,int nLen) nnGA_7-t
{ .`'SL''c
int n = -1; Bhq(bV
try{ !RcAJs'
oSavedFile.write(b,nStart,nLen); T (2,iG8
n = nLen; y]jh*KD[
} Mz++SPG7
catch(IOException e) ^Js9E
{ 3Xh&l[.
e.printStackTrace (); 8&C(0H]1
} Jj6kZK
tiE+x|Ju"
$m=z87hX
return n; \[oHt:$do
} C]=E$^|{
<dYk|5AdLF
;5|EpoM
} &yA<R::o
g?$9~/h :;
CLkVe
/* I(<G;ft<}
**SiteInfoBean.java 4P~<_]yf
*/ GC\/B0!
package NetFox; kN$70N7I;
QNJG}Upl
D1Sl+NOV
public class SiteInfoBean { f.P( {PN
yY| .
H);'\]_'x
private String sSiteURL; //Site's URL ]czy8n$+
private String sFilePath; //Saved File's Path iE Oyc59
private String sFileName; //Saved File's Name #] GM#.
private int nSplitter; //Count of Splited Downloading File 5?fk;Q9+\
2DC#PX)i
#`fT%'T!
public SiteInfoBean() >ATW/9r
{//nSplitter的缺省值为5 eLYFd,?9
//default value of nSplitter is 5 f!J^vDl
this("","","",5); 8 KkpXaz
} +-nQ, fOV
&rd(q'Vi
h[8y$.YsC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S }n;..{
{ 2bJFlxEU
sSiteURL= sURL; <di_2hN
sFilePath = sPath; L&N"&\K2U
sFileName = sName; flB,_
this.nSplitter = nSpiltter; \+uqP:Ty
biG9?
84[^#ke
} r9Z/y*q
u7=[~l&L
'JMa2/7CG
public String getSSiteURL() $aA.d^
{ K(d!0S
return sSiteURL; \$C4H
} SHk[X ]Uo
+Y~+o-_
W =zG
public void setSSiteURL(String value) g=C<E2'i*
{ E%^28}dN
sSiteURL = value; yx2.7h3
} }SV3PdE
v/czW\z
fI1;&{f
public String getSFilePath() Du>HF;Fv
{ 3I5WDuq
return sFilePath; QRlzGRueR&
} Ng"vBycy
i-?zwVmn
@;6}xO2
public void setSFilePath(String value) cWc)sb
{ $P(nh'\
sFilePath = value; #FB>}:L{h*
} [!&k?.*;<
A,{D9-%
xiF%\#N
public String getSFileName() M: "ci;*$
{ rl%Kn^JJ~
return sFileName; 9>R|k$`
} .e"Qv*[^
(g m^o{
X^Y9T`mQ}
public void setSFileName(String value) pCmJY
{ Fw9``{4w
sFileName = value; GX)QIe~;qJ
} :*@|"4
*$(CiyF!
@WHd(ka!
public int getNSplitter() 5S]P#8
{ `5-#M/J
return nSplitter; FA9e(Ha
} w.aFaR)04
{0e{!v
a{*'pY(R0$
public void setNSplitter(int nCount) ({KAh?
{ dCP Tpm
nSplitter = nCount; s7o*|Xv
} #`4^zU)
} t4@g;U?o
6\Vu#r
MNqyEc""
/* g u =fq\`
**Utility.java \hW73a!
*/ eH955[fVd4
package NetFox; q"D L6 >j
!>y}Xq{bm3
+)JqEwCrq
public class Utility { |u;BAb
/JeqoM"x
W<91m*
public Utility() &PuJV +y
{ 3cO[t\/up
+g6j=%
)ek 5
} \a2oM$PX
GFdJFQio
//线程睡眠 sK-|xU.
public static void sleep(int nSecond) jL+}F/~r
{ 'uACoME@
try{ hav?mnVJ
Thread.sleep(nSecond); N#['fg'
} ~_db<!a
catch(Exception e) P .4b+9Tx
{ L*01l"5
e.printStackTrace (); l;}7A,u
} ,beR:60)
} jfPJ5]Z
bNjaCK<
//日志 fC GDL6E
public static void log(String sMsg) J5p!-N`NS
{ ,35:Srf|
System.err.println(sMsg); mUyv+n,
} $v<hW A]>
}t D!xI;
&9dr+o-(~
public static void log(int sMsg) y2"S\%7$h
{ z!C4>,
System.err.println(sMsg); G\>\VA
} +.#S[G
} x";.gjI |g
sx<+ *Trl
s.`%ZDl@Y
/* *!]Epb
**TestMethod.java 199hQxib:
*/ _2X6bIE
package NetFox; 8wpwJs&V
renmz,dJ,
Be>c)90bO_
public class TestMethod { O<Sc.@~
_HHJw""j
VWA-?%r
public TestMethod() 2PP-0 E
{ ///xx/weblogic60b2_win.exe W[X!P)=w]
try{ 5?{ >9j5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _l!U[{l*d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g1 Wtu*K3
SiteFileFetch fileFetch = new SiteFileFetch(bean); yp2'KES>
fileFetch.start(); TQ\wHJ
} fFZ`rPb
catch(Exception e){e.printStackTrace ();} MZMS?}.2
xK),:+G(
S,Wl)\
} b8{h[YJL2
b!5tFX;J
OwiWnS<
public static void main(String[] args) gvc' $9%
{ v>y8s&/
new TestMethod(); *fvI.cKiGP
} 3w^J"O/T
} ^,Y~M_=
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