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)); s^obJl3
} I?A~zigO
for(int i=0;i<nEndPos.length-1;i++) 7/4~>D&-b
{ RlPjki"Mg
nEndPos = nStartPos[i+1]; +<H !3sW
} YdPlN];[
nEndPos[nEndPos.length-1] = nFileLength; vW9^hbdx
} {~":;
} X3<SP
Yo>%s4_,
Cx$9#3\
//启动子线程 BzN/6VEw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3HXh6( e
for(int i=0;i<nStartPos.length;i++) z/pDOP Ku
{ Xx=K?Z?3.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nIG[{gGX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Mp!2`4rD
nStartPos,nEndPos,i); XL=2wh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O^y$8OKEi,
fileSplitterFetch.start(); 0qOM78rE
} b$IY2W<Ln
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UnJi& ~O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ua}g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K@I+]5E%?
nEndPos = " + nFileLength); #@IQlqJfY7
// fileSplitterFetch[nPos.length-1].start(); n(9F:N
Lqg7D\7j
w6%l8+{R
//等待子线程结束 5/*)+
//int count = 0; <Wp`[S]r
//是否结束while循环 9Y;}JVS
boolean breakWhile = false; <?{ SU
~_(!}V
_.u~)Q`6
while(!bStop) \?aOExG I
{ % E<FB;h
write_nPos(); 3L%Y"4(mm
Utility.sleep(500); D "JMSL4r
breakWhile = true; AviT+^7E
77)OW$G
^w.k^U=B
for(int i=0;i<nStartPos.length;i++) VG? yL2y
{ A)=X?x
if(!fileSplitterFetch.bDownOver) }Ox2olUX
{ Z`e$~n(Bh
breakWhile = false; ':5U&
break; tW'qO:y+
} ZKVp[A
} [I#Q
if(breakWhile) ;""-[4C
break; = .fc"R|<K
8f5%xY$
<6~/sa4GN
//count++; `PXoJl
//if(count>4) !.x=r
// siteStop(); O%rS;o
} rCV$N&rK
LX&=uv%-^
!H2C9l:rd
System.err.println("文件下载结束！"); MZgmv
} &Z#Vw.7U
catch(Exception e){e.printStackTrace ();} I$rW[l2
} "i;*\+x
&e5^v
"Wzij&WkQ
//获得文件长度 Z3&XTsq
public long getFileSize() T#ecLD#
{ vLVSZX
int nFileLength = -1; Ktj(&/~}
try{ 3/]f4D{MMY
URL url = new URL(siteInfoBean.getSSiteURL()); -K{\S2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #$9U=^Z[
httpConnection.setRequestProperty("User-Agent","NetFox"); ;tZ}i4Ud
C={sE*&dYX
p1[WGeV
int responseCode=httpConnection.getResponseCode(); f)!{y>Q
if(responseCode>=400) &q kl*#]
{ wpPxEp/
processErrorCode(responseCode); FuRn%)DA5
return -2; //-2 represent access is error >rQ)|W=i
} [C*Xk{e
~cWLu5
Pj^k pjV
String sHeader; ]}*G[[ ^p
+LvZ87O^~
SV$ASs
for(int i=1;;i++) XF0*d~4
{ >QbI)if`1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mo97GW
//Utility.log(in.readLine()); |2+c DR
sHeader=httpConnection.getHeaderFieldKey(i); i1kh@s~8UC
if(sHeader!=null) lW@:q04Z$
{ #==[RNM%ap
if(sHeader.equals("Content-Length")) JJ= ~o@|c
{ +#2@G}j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y2d_b/
break; Tg}H < T
} '8iv?D5M
} >Kqj{/SWK
else 6Wcn(h8%*
break; s?z=q%-p
} V3.vE,
} e3bAT.P
catch(IOException e){e.printStackTrace ();} [9##Kb
catch(Exception e){e.printStackTrace ();} 7i%P&oB
m''iE
wZ#~+ }T
Utility.log(nFileLength); _'o^@v:
Sxx.>gP"61
\p_8YC
return nFileLength; ,& {5,=
} `OF g.R|
l"V8n BR`
&vGEz*F
//保存下载信息（文件指针位置） =h1 QN
private void write_nPos() WHh2fN'A5
{ e=NQY8?
try{ %QlBFl0a
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;U5x'}%0]
output.writeInt(nStartPos.length); U~QCN[gh
for(int i=0;i<nStartPos.length;i++) o8yEUnqN
{ ~vvQz"
// output.writeLong(nPos); ?PH}b?f4
output.writeLong(fileSplitterFetch.nStartPos); xHR+((
output.writeLong(fileSplitterFetch.nEndPos); $T@xnZ
} :+X2>Lu$FA
output.close(); 'FvhzGn9Q
} 1]zyME
catch(IOException e){e.printStackTrace ();} 7Ohu$5\
catch(Exception e){e.printStackTrace ();} L<nkI
} 5>^ W}0s
qhHRR/p
hwb(W?*
//读取保存的下载信息（文件指针位置） p{pzOMi6
private void read_nPos() }<x!95
{ H;"N|pBy
try{ #h|,GvmF<b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lQ(BEv"2G[
int nCount = input.readInt(); Tef3 Z6
nStartPos = new long[nCount]; ^?l-YnQqm?
nEndPos = new long[nCount]; "=0lcbC
for(int i=0;i<nStartPos.length;i++) j,V$vKP
{ lyc{Z%!3
nStartPos = input.readLong(); Z~.]ZWj-
nEndPos = input.readLong(); E;+OD&|
} 1Tk\n
input.close(); ?5+KHG*)
} GF,|;)ly
catch(IOException e){e.printStackTrace ();} z]R!l%`
catch(Exception e){e.printStackTrace ();} UEdl"FwM4
} I]j/ ab7>
77[;J
.]d tRH<
private void processErrorCode(int nErrorCode) y{},{~FA"
{ "5z6~dq
System.err.println("Error Code : " + nErrorCode); @):NNbtA
} F7PZV+\
X;[zfEB
'%r@D&*vp
//停止文件下载 =xQfgj
public void siteStop() "/]tFY%Y
{ "u>sS
bStop = true; ucm.~1G(
for(int i=0;i<nStartPos.length;i++) ?;=Y1O7N(
fileSplitterFetch.splitterStop(); 9Z_OLai
'V1 -iJj9
UHDI9>G~,
} i(qYyO'
} C%7,#}[U/
//负责部分文件的抓取 i{x0#6_Y
**FileSplitterFetch.java %}AY0fg?T
*/ WoT z'
package NetFox; FT?1Q'
IgnY*2FT
7Mbt*[n
import java.io.*; >rX R;4%
import java.net.*; Nb,H8;
&_x/Dzu!z
_nCs$U
public class FileSplitterFetch extends Thread { !/lYq;$R
o_^d>Klb8
af5`ktx
String sURL; //File URL _=M'KCL*)
long nStartPos; //File Snippet Start Position ;.[$
long nEndPos; //File Snippet End Position *Zo o
int nThreadID; //Thread's ID |~vQ0D
boolean bDownOver = false; //Downing is over GZ>% &^E
boolean bStop = false; //Stop identical ^T1-dw(
FileAccessI fileAccessI = null; //File Access interface }u*@b10
YD>>YaH_3@
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w*R-E4S?2
{ a/`Yh>ou
this.sURL = sURL; |ssIUJ
this.nStartPos = nStart; 1&L){hg
this.nEndPos = nEnd; (dprY1noC
nThreadID = id; ;77o%J'l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zkep7L
} xWZcSIH!
j24
KO;61y:
public void run() ')cgx9
{ 2g8P$+;
while(nStartPos < nEndPos && !bStop) $%"}N_M
{ N5_.m(:
wLp t2b8S
])l[tVHm
try{ zi&d
URL url = new URL(sURL); g#2X'%&+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9<r}s
httpConnection.setRequestProperty("User-Agent","NetFox"); s7.*o@G
String sProperty = "bytes="+nStartPos+"-"; NB#*`|qt
httpConnection.setRequestProperty("RANGE",sProperty); 13az[
Utility.log(sProperty); NKh{iSLm
:|mkI#P.
:pu{3-n.
InputStream input = httpConnection.getInputStream(); %hb5C 4q
//logResponseHead(httpConnection); tLXw&hFk`g
4'=N{.TtO
._nKM5.
byte[] b = new byte[1024]; >o=p5#{
int nRead; T/6=A$4 #
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0e](N`
{ ,(=]6V
nStartPos += fileAccessI.write(b,0,nRead); diLl>z
//if(nThreadID == 1) vj$6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); twS3J)UH
} 0qUap*fvC
D8{HOv;d^
vaZZzv{H
Utility.log("Thread " + nThreadID + " is over!"); %$KO]
bDownOver = true; A>2p/iMc
//nPos = fileAccessI.write (b,0,nRead); JU.%;e7
} z$5C(!)
catch(Exception e){e.printStackTrace ();} L2$L.@
} D*Q#G/TF3
} /8HO7E+5
~8{3Fc0
bD-Em#>
//打印回应的头信息 'vIkA=
public void logResponseHead(HttpURLConnection con) 5hK\YTU
{ LkB!:+v |B
for(int i=1;;i++) GK%ovK
{ *03/:q^(
String header=con.getHeaderFieldKey(i); v('d H"Y
if(header!=null) *?"{T;4u~O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <BA&S _=4
Utility.log(header+" : "+con.getHeaderField(header)); 5z>\'a1U
else R u-rp^a
break; AAY UXY!
} y]%,Y=%X
} 9iNns;^`q
F ;&e5G
u.FDe2|[)
public void splitterStop() W (=B H
{ "-:\-sMt{
bStop = true; .p}Kl$K]
} /CE d14.
T+D]bfjr&&
<~+
} N+75wtLy&
LS$82UB&
h'KtG<+
/* .U%"oD
**FileAccess.java rv%[?Ml
*//文件访问(定位，写) }O
package NetFox; l$9,
import java.io.*; 74(J7
1iDo$]TEK
H12@12v
public class FileAccessI implements Serializable{ 8E[`H
V,5}hQJ F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x&vD,|V!
RandomAccessFile oSavedFile; LL [>Uu?Y
long nPos; e6'O,\
TMsoQ82
i8.[d5
public FileAccessI() throws IOException +cH(nZ*f
{ 1D6O=j\
this("",0); \TlUC<urP
} oy: MM
2&URIQg*J
#{,IY03
public FileAccessI(String sName,long nPos) throws IOException V/e_:xECC
{ ]L^M7SKE6
oSavedFile = new RandomAccessFile(sName,"rw"); w%n]~w=8
this.nPos = nPos; ,2bAKa
oSavedFile.seek(nPos); H/Q)zDP
} }C.{+U
=rF8[Q0K
[+z:^a1?V
public synchronized int write(byte[] b,int nStart,int nLen) E ET 2|*}
{ V p{5Kxq
int n = -1; #+k[[; 0
try{ yFsXI0I[p
oSavedFile.write(b,nStart,nLen); pnJT]?},
n = nLen; qTF>!o#\:
} tvRy8u;
catch(IOException e) UV.9KcN.
{ 5 ZPUY
e.printStackTrace (); x~eEaD5m%J
} $uhDBmb
koZp~W-
p04+"
return n; "cM5=;
} ^mQfXfuL
I_7EfAqg(
It-*CD9
} q2vz#\A?
fM.|#eLi
A!yLwkc:5
/* d 4R+gIA
**SiteInfoBean.java G.TX1
*/ f4}6$>)
package NetFox; ?UDO%`X
)A=g# D#
yfQE8v+
public class SiteInfoBean { faX#KRpfd
MX,0gap
[bJnl>A
private String sSiteURL; //Site's URL G[j79o
private String sFilePath; //Saved File's Path ]M;! ])b$
private String sFileName; //Saved File's Name 7:'>~>'
private int nSplitter; //Count of Splited Downloading File c F]3gM
=lQ[%&
H%aLkV!J
public SiteInfoBean() ;(6lN<iU
{//nSplitter的缺省值为5 |3ETF|)?
//default value of nSplitter is 5 $t'I*k^N
this("","","",5); B)8Hj).@B
} vI}S6-"<
k]pD3.QJ
;jI"|v{vnS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'U$VOq?!
{ W=]",<
sSiteURL= sURL; z-gG(
sFilePath = sPath; ~W{h-z%q
sFileName = sName; v*'\w#
this.nSplitter = nSpiltter; [S+-ovl
^?[<!VBI
cLC7U?-
} NI:N W-!
VTfaZ/e.
L-{r*ccIW
public String getSSiteURL() olh3 R.M<
{ #)}bUNc'
return sSiteURL; t'x:fO?cp
} of
-$z"74
rd4'y~#S
public void setSSiteURL(String value) yt:V+qdv
{ 5>Yd\(`K
sSiteURL = value; gi@ji-10
} q.km>XRk~
wJ*-K-
Cbs4`D,
public String getSFilePath() ?^4sE-C6
{ IkNt! 2s_
return sFilePath; +Z2<spqG
} KXCmCn
Q9tE^d+%
qFbUM;
public void setSFilePath(String value) )0MshgM
{ })vr*[
sFilePath = value; E?U]w0g
} u(WQWsN
>ImM~SR)
1t=X: ]0j
public String getSFileName() dU^<7 K:S
{ ATp 6-
return sFileName; 4 xzJql
} r;8z"*
N@a'd0oTd
|ZlT>u
public void setSFileName(String value) 166c\QO
{ ]pTw]SK
sFileName = value; .ASwX
} m>dcb 6B+g
y]f^`2L!8>
fYM6wYJ
public int getNSplitter() (H%d]
{ CVG>[~}(9'
return nSplitter; EFt`<qwj
} <`UG#6z8
C_ZD<UPA\
H-KwkH`L4
public void setNSplitter(int nCount) _D,f4.R
{ mX.3R+t
nSplitter = nCount; I4f
} Mq lo:7 ^F
} @EOR]^?!]
M2P@ &
]O=S2Q
/* -<JBKPtA
**Utility.java [*{\R`M
*/ |$?Ux,(6
package NetFox; \(U"_NPp
'EET3RK-S
PeUd
public class Utility { 39aCwhh7v
C2=iZ`Z>T
rspoSPnY1
public Utility() 3kqV_Pjg
{ xZ=FH>Y6'
t^_{5
\i;&@Kp.N
} u$=ogp=0
w*xUuwi
//线程睡眠 jvc?hUcLKT
public static void sleep(int nSecond) '}pgUh_
{ ' raB
try{ iVi3 :7*
Thread.sleep(nSecond); ^HlLj#
} %*6oUb
catch(Exception e) nB@iQxcz
{ m9<%v0r
e.printStackTrace (); #+Yp^6zg
} Sa?5iFg
} }vUlTH
M?~<w)L}
//日志 ncJFB,4
public static void log(String sMsg) feI[M;7u
{ Z~phOv
System.err.println(sMsg); FO(0D?PCR
} 7?!Z+r
%][$y7
IgiF,{KE,
public static void log(int sMsg) H(NT|
{ 5hH6G
System.err.println(sMsg); AXh3LA
} M o"JV
} Jm(&G
hLytKPgt
Rw/JPC"
/* 2^ ,H_PS
**TestMethod.java i+X2M-[Ls
*/ NrJ_6sjF0g
package NetFox; Y7kb1UG
a?,[w'7FU
Y=:KM~2hv
public class TestMethod { o!=lBfI
OSa}8rlr'
4Ay`rG
public TestMethod() j.;
{ ///xx/weblogic60b2_win.exe fZ6 fV=HEF
try{ .mT#%ex
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); txml*/zL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x>^3]m
SiteFileFetch fileFetch = new SiteFileFetch(bean); &vFqe,Z
fileFetch.start(); Kl aZZJ
} j FPU zB"
catch(Exception e){e.printStackTrace ();} <K,% y(]
O@r.>
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} RrO0uadmn
Q$3\ /mz
oEQ{m5O9
public static void main(String[] args) i[2bmd!H
{ s^g.42?u
new TestMethod(); .L^pMU+!^
} !]rETP_
} pFsCd"zv
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