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)); Djf2ir'
} toTAWT D
for(int i=0;i<nEndPos.length-1;i++) /dOQ4VA\
{ pRc(>P3;
nEndPos = nStartPos[i+1]; y(.WK8
} !nVX .m9
nEndPos[nEndPos.length-1] = nFileLength; 1sc #!^Oo
} mm#U a/~1u
} TOMvJ>bF
g/z9bOgIX
e/;Ui
//启动子线程 Kox~k?JK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b,T=0W
for(int i=0;i<nStartPos.length;i++) Zpb3>0<R
{ }J`{g/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2l5@gDk5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [%l+ C~m
nStartPos,nEndPos,i); EUuMSDp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '4Z%{.;
fileSplitterFetch.start(); ^0{S!fs
} m_rRe\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e7#=F6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qx0o,oZN!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V<4)'UI?k9
nEndPos = " + nFileLength); (!X:[Ah*$
// fileSplitterFetch[nPos.length-1].start(); u6r-{[W}
xDADJ>u2K
mSQ!<1PM
//等待子线程结束 W\~ZmA.
//int count = 0; "r"]NyM
//是否结束while循环 /Z2*>7HM8[
boolean breakWhile = false; qWE"vI22M
nj7Ri=lyS
Z/-%Eb]L1
while(!bStop) '2[ _U&e
{ ^"buF\3L
write_nPos(); ?U-p jjM
Utility.sleep(500); '[-H].-!
breakWhile = true; ^;@Bz~Z
'3hvR4P
)1x333.[c
for(int i=0;i<nStartPos.length;i++) 0l 3RwWj
{ /-|xxy
if(!fileSplitterFetch.bDownOver) $ @1&G~x
{ `SW`d<+L
breakWhile = false; -IX;r1UD
break; MeplM$9
} 8#Z$}?W
} RuRJjcnY
if(breakWhile) e:7aVOm
break; N,[M8n,
cQ+,F2
'!1lK
//count++; p$9N}}/c
//if(count>4) R*yB);p
// siteStop(); K4RjGSaF
} $^ >n@Q@&L
V;:A&
9h0|^ttF
System.err.println("文件下载结束！"); > %Y#(_~a
} T3?kabbF
catch(Exception e){e.printStackTrace ();} ;F0A\5I
} -5>g 0o2
T@vVff
>LLzG
//获得文件长度 *n[Fl
public long getFileSize() Sr+1.77}
{ A,=l9hE'
int nFileLength = -1; wK\SeX
try{ 3QR-8
URL url = new URL(siteInfoBean.getSSiteURL()); *v5y]E%aW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a9qZI
httpConnection.setRequestProperty("User-Agent","NetFox"); g)p[A 4
=G72`]#-
cxv)LOl-
int responseCode=httpConnection.getResponseCode(); pEaH^(I*
if(responseCode>=400) }oU&J81
{ ~~fL`"
processErrorCode(responseCode); WYzY#-j
return -2; //-2 represent access is error gTQ6B,`/8
} Xs?>6i@$$
zYs? w=
(f.A5~e
String sHeader; ?t%5/
<kM%z{p
EwOTG Y{0p
for(int i=1;;i++) .-34g5
{ d[Fsp7U}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'V>+G>U
//Utility.log(in.readLine()); e| l?NXRX
sHeader=httpConnection.getHeaderFieldKey(i); 2'}2r ~6
if(sHeader!=null) =VSieh
{ {Y/
if(sHeader.equals("Content-Length")) < 1r.p<s
{ LaIif_fie^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ){(cRB$
break; SMy&K[hJ[
} LpiLk| 2i
} d)AkA\neWo
else a*D|$<V
break; QMsnfG
} EPg?jKZava
} #nxx\,i>
catch(IOException e){e.printStackTrace ();} u4nXK <KL|
catch(Exception e){e.printStackTrace ();} Fca?'^X
wvYxL c#p0
aOuon0
Utility.log(nFileLength); W>Kwl*Cis"
VuR BJ2D
x$p\ocA
return nFileLength; 97g-*K
} ejQCMG7
=0-qBodbl
Z:OO|x
//保存下载信息（文件指针位置） KWYG\#S0]
private void write_nPos() 0qZ)$YKq
{ g[n8N{s
try{ FPMk&
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;K_B,@:'
output.writeInt(nStartPos.length); g-s@m}[T
for(int i=0;i<nStartPos.length;i++) V:+bq`
{ oe<Y,%u"6
// output.writeLong(nPos); hh{liS% 10
output.writeLong(fileSplitterFetch.nStartPos); OH(+]%B78
output.writeLong(fileSplitterFetch.nEndPos); i0!F
} f_\-y&)+*
output.close(); kO#`m]
} )}aF=%
catch(IOException e){e.printStackTrace ();} K_xOY *
catch(Exception e){e.printStackTrace ();} h^c'L=dR
} (l,o UBRr
sDC RL%0QK
5C&f-* Bh
//读取保存的下载信息（文件指针位置） |q>Mw-=
private void read_nPos() utE:HD.PN
{ 5 6R,+sN
try{ !<)_ F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GwycSb1
int nCount = input.readInt(); M}<=~/k`j
nStartPos = new long[nCount]; +u2Co_FJ&
nEndPos = new long[nCount]; D^~gq`/)
for(int i=0;i<nStartPos.length;i++) {MtB!x
{ ^`7t@G$ D
nStartPos = input.readLong(); t<7WM'2<y
nEndPos = input.readLong(); yKI.TR#
} V Y3{1Dlf
input.close(); Yp)U'8{h c
} 00p 7sZU^
catch(IOException e){e.printStackTrace ();} Ed-gYL^<
catch(Exception e){e.printStackTrace ();} w;(gi
} {|%O)fr,
[:'n+D=T3M
C"{on%
private void processErrorCode(int nErrorCode) yM2&cMHH~
{ LA+MX0*
System.err.println("Error Code : " + nErrorCode); v3"xJN_,[p
} lN'/Z&62
H-W)Tq_?-
a\w|tf
//停止文件下载 "=(;l3-o
public void siteStop() {Jc!T:vJ
{ aiHr2x6
bStop = true; d/&|%Z r
for(int i=0;i<nStartPos.length;i++) \_E.%K
fileSplitterFetch.splitterStop(); fz3*oJ'
pYG,5+g
* 2%e.d3"M
} Uz|]}t5V
} Om
//负责部分文件的抓取 q9!9OcN2
**FileSplitterFetch.java 4QNR_w
*/ ->8q, W2A
package NetFox; d@tr]v5 B
`[CJtd2\
E2|iAT+=.
import java.io.*; obq}#
import java.net.*; M<unQ1+wh
+a-@ !J~:
W6T&hB
public class FileSplitterFetch extends Thread { 5KR|pFq
6~ `bAe`}
+df?N
String sURL; //File URL (do=o&9pm
long nStartPos; //File Snippet Start Position hhGpB$A
long nEndPos; //File Snippet End Position H\mVK!](D
int nThreadID; //Thread's ID %#9~V
boolean bDownOver = false; //Downing is over YkPt*?,P/
boolean bStop = false; //Stop identical 0Q>|s_
FileAccessI fileAccessI = null; //File Access interface E+zn\v
fJ2{w[ne
z-5#bOABW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0)5Sx /5'
{ GuWBl$|+b
this.sURL = sURL; h\d($Ki
this.nStartPos = nStart; PEEY;x
this.nEndPos = nEnd; Z!reX6
nThreadID = id; ZPao*2xz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _KVB~loT
} :, [!8QP
#ya|{K
->I{ :#
public void run() I%919
{ HDyZzjgG
while(nStartPos < nEndPos && !bStop) \STvBI?
{ B5HdC%8/}
vXyo
:QV6z*#zD
try{ B:4qW[U#
URL url = new URL(sURL); ~^~RltY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tq[",&K
httpConnection.setRequestProperty("User-Agent","NetFox"); \)ZX4rs{8
String sProperty = "bytes="+nStartPos+"-"; t[,T}BCy.
httpConnection.setRequestProperty("RANGE",sProperty); (B,t 1+%
Utility.log(sProperty); *u'`XRJU/
Wmxw!
$S8bp3)
InputStream input = httpConnection.getInputStream(); +A?+G
//logResponseHead(httpConnection); Q 02??W
$Wzv$4;
[KI`e
byte[] b = new byte[1024]; Ko|xEz=
int nRead; OW}j4-~wL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zl 0^EltiU
{ ;n{j,HB
nStartPos += fileAccessI.write(b,0,nRead); dG>Wu o
//if(nThreadID == 1) 8/?uU]#Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Ntdl:fSw
} }|"*"kxi!
)^S^s>3
b[o"Uq@8?
Utility.log("Thread " + nThreadID + " is over!"); :YXQ9/iRr
bDownOver = true; Qfu*F}
//nPos = fileAccessI.write (b,0,nRead); 2G5!u)
} <VR&=YJ
catch(Exception e){e.printStackTrace ();} G!LNP&~
} j_uY8c>3\q
} *2 $m>N
#'Y6UGJ\n
a 8hv.43
//打印回应的头信息 7WfirRM
public void logResponseHead(HttpURLConnection con) 9Q7cUoxY
{ `[` *@O(y
for(int i=1;;i++) A;j$rGx
{ FJ,\?ooGf
String header=con.getHeaderFieldKey(i); *5'6E'
if(header!=null) >\x_"oR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G%8)6m'3
Utility.log(header+" : "+con.getHeaderField(header)); rn[}{1I33Q
else 4i\aW:_'i
break; ^=Tu>{uD
} h8= MVh(I
} <T.#A8c
C\2>7
UFAMbI
public void splitterStop() \v P2B
{ 27YLg c
bStop = true; *o\Y~U-so
} l)PFzIz=V
vua1iN1
aco}pXz
} l^y?L4hg)
<_{4-Q>S3#
fRa-bqQ
/* u3i|}`
**FileAccess.java "ko?att~
*//文件访问(定位，写) M3;v3 }z<-
package NetFox; ?]:EmP
import java.io.*; g yH7((#i
sEJ;t0.LX
k#:@fH4{PA
public class FileAccessI implements Serializable{ Hs`#{W{.
!_z<W~t"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /Zeg\}/4[
RandomAccessFile oSavedFile; zmfRZ!Eh
long nPos; %)hIpxOrX
Or#+E2%1E
vH?+JN"A
public FileAccessI() throws IOException pT;-1c%:
{ c>WpOZ,
this("",0); 'UXj\vJ3E
} -G<2R"Q#N
B/9<b{6
IU'!?XVo
public FileAccessI(String sName,long nPos) throws IOException N" Jtg@w
{ MHr0CYyb.
oSavedFile = new RandomAccessFile(sName,"rw"); am'p^Z@
this.nPos = nPos; `\4JwiPo
oSavedFile.seek(nPos); Wh'_slDH+
} ;GgQ@s@
;aK !eD$
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public synchronized int write(byte[] b,int nStart,int nLen) gQpD]p%k
{ mA] 84zO
int n = -1; +?5Uy*$
try{ hzuMTKH9
oSavedFile.write(b,nStart,nLen); ND55`KT4
n = nLen; "J[i=~(
} : `6$/DK
catch(IOException e) id#k!*$7
{ pJ$N@ID
e.printStackTrace (); Ibv_D$cT
} At[n<8_|
mp+\!
Z/6'kE{l
return n; K'{W9~9Lq
} LnI{S{]wDh
~q]|pD"\K|
:af;yu
} Q1ABnacR
}2BH_ 2
[>M*_1F
/* [,o5QH\Etq
**SiteInfoBean.java v1X&p\[d
*/ z^a!C#IX
package NetFox; ),y!<\oQ
rm)SfT<
!8"$d_=h
public class SiteInfoBean { JX\T {\m#
10l1a4
QC\g%MVG
private String sSiteURL; //Site's URL rPo\Dz
private String sFilePath; //Saved File's Path {7Gx9(
private String sFileName; //Saved File's Name )(?UA$"
private int nSplitter; //Count of Splited Downloading File }KaCf,O
{Z?$Co^R
+.gf]|
public SiteInfoBean() sQ>B_Y!
{//nSplitter的缺省值为5 b!^M}s6
//default value of nSplitter is 5 RZ<+AX9R
this("","","",5); %+7T9>+
} e0|_Z])D
UP~WP@0F
1hMX(N&|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =~W0~lxX
{ -|k&L}\OB0
sSiteURL= sURL; S4{Mu(^xT
sFilePath = sPath; z7@(uIl=X
sFileName = sName; |B1;l<|`
this.nSplitter = nSpiltter; vU8FHVytV
"3Xv%U9@
<9d-Hz
} ,yM}]pwlB
C$'D]fX
bU:}ZO^S
public String getSSiteURL() 2Pem%HE~P
{ oXQ<9t1(
return sSiteURL; dIk8TJ
} fOK+DT~
k binf
:p\(y
public void setSSiteURL(String value) zU4V^N'
{ 6HEqm>Yau
sSiteURL = value; Ha=_u+@
} 'd2qa`H'}B
}:RT,<
%EJ\|@N:
public String getSFilePath() pT3X/ra
{ {w |dM#
return sFilePath; &sZ9$s:(^
} _X,[]+ziu%
/slm ]'
*gM,x4Y
public void setSFilePath(String value) EI=Naq
{ [w&#+h-q
sFilePath = value; O2`oe4."vd
} JGk3b=K
f.aB?\"f6
?u_gXz;A
public String getSFileName() #K:-Bys5v
{ $S6HZG:N
return sFileName; }XGMa?WR
} BrlzN='j}
cQ3W;F8|n
0|fb< "
public void setSFileName(String value) n) _dH/"
{ E(QZ!'%K+m
sFileName = value; ?fbgU
} FGDGWcRw~
(B_7\}v|_
"EcX_>
public int getNSplitter() |+Hp+9J
{ ~Ho{p Oq
return nSplitter; %YcxC0S[
} kf%&d}2to
"*++55
T3USNc51
public void setNSplitter(int nCount) .>mH]/]m
{ ]>R`;"(
nSplitter = nCount; JmU<y
} g.B%#bfg
} e/"yGQu
X q}Ucpj
HE#,(;1i
/* lZ|L2Yg3uB
**Utility.java ||-nmOy
*/ Vs#"SpH{'
package NetFox; z-EwXE
B ~fSMB6h
nS_Ta
public class Utility { @~m=5C
<Rcu%&;i
[[R7~.;
public Utility() !dU9sB2
{ ;y>S7n>n:
o"rq/\ovv
'|vD/Qf=&
} Tub1Sv>J
"w}-?:# j
//线程睡眠 f4]N0
public static void sleep(int nSecond) "z rA``
{ E,{GU
try{ {>8Pl2J
Thread.sleep(nSecond); )y9;OA
} Y/.AUN Z
catch(Exception e) &+mV7o
{ V]79vC
e.printStackTrace (); ifXW
} !M
} Ye9Y^+-
x(L(l=^"
//日志 ,N53Iic
public static void log(String sMsg) &4,WG
{ |u@+`4o
System.err.println(sMsg); :.*HQt9N
} ""co6qo#>
QX[Djz0H8
n[!;yO
public static void log(int sMsg) 6cM<>&e
{ \)ip>{WG
System.err.println(sMsg); =96G8hlT
} Zp?4uQ)[W
} C:]s;0$3'9
8wr8:(Y$
\gLxC
/* k`Nyi)AGe
**TestMethod.java D^Te%qnW
*/ w/ TKRCO3
package NetFox; l , ..5
qu_)`wB
u*2fP]n
public class TestMethod { ]kx-,M(
P0^c?s"I
8{dEpV*
public TestMethod() ;HDZ+B
{ ///xx/weblogic60b2_win.exe S}[l*7
try{ 3y99O $EAc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KU-'+k2s;p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 11@]d]v ,
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q]@c&*_|
fileFetch.start(); <3A0={En
} 4'',6KJ@
catch(Exception e){e.printStackTrace ();} yL6^\x
C,/O
H@GE)I>^@
} o\Uu?.-<
1BJ<m5/1%
6B0#4Qrv
public static void main(String[] args) Gav"C{G
{ H$!+A
new TestMethod(); Z7fg 25
} qj&bo
} owvS/"@
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