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)); PJ&L7
} $0OOH4
for(int i=0;i<nEndPos.length-1;i++) &PApO{#Q
{ S[hyN7sI
nEndPos = nStartPos[i+1]; +e.w]\}
} 8QL=%Pv
nEndPos[nEndPos.length-1] = nFileLength; HCkfw+gaV
} V )UtU L
} 3b#L*-
;ThFB
4Z=`;
//启动子线程 ] >w@@A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &tf(vU;,'
for(int i=0;i<nStartPos.length;i++) Z'uiU e`&
{ A)j!Wgs^z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }kItVx
nStartPos,nEndPos,i); n'q:L(`M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5`:d$rv
fileSplitterFetch.start(); 0y/31hp
} ~:0w%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .#iot(g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?* ,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f9<"
nEndPos = " + nFileLength); \RPwSx
// fileSplitterFetch[nPos.length-1].start(); gs/ocu
z$d<ep{6
\o72VHG66
//等待子线程结束 -&]!ig5v
//int count = 0; l\Ww^
//是否结束while循环 D:IG;Rsc
boolean breakWhile = false; M=&,+#z<V
/J!:_Nq
KZ#\ >
while(!bStop) QS\wtTXj
{ P zM yUv
write_nPos(); <HN{.p{
Utility.sleep(500); olL? 6)gC
breakWhile = true; 1ZRkVHiz0
Q(q&(/
cPAR.h,b?
for(int i=0;i<nStartPos.length;i++) ZvT>A#R;l~
{ u^JsKG+,:
if(!fileSplitterFetch.bDownOver) YHu]\'Ff
{ lsOfpJ
breakWhile = false; n{etDO
break; (dQ=i
} ,d*hhe
} 1iLU{m9
if(breakWhile) [.Kp/,JY
break; 1kvs2
#,6T.O
u-:3C<&>
//count++; ; Ad5Jk
//if(count>4) ,p(&G_
// siteStop(); Ks6\lpr
} /Yg&:@L
S++~w9}
1 JIU5u)
System.err.println("文件下载结束！"); ?YS 3)
} SA=>9L,2
catch(Exception e){e.printStackTrace ();} v*dw'i
} :Y1;= W
'6>*J
<LXx_{=:
//获得文件长度 xh9$ZavB*
public long getFileSize() o59$vX,
{ b.\xPb
int nFileLength = -1; V?wV*]c
try{ 3b]M\F9
URL url = new URL(siteInfoBean.getSSiteURL()); r;[=y<Yf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +DR$>a
httpConnection.setRequestProperty("User-Agent","NetFox"); woPj>M
b l+g7g;
+`{OOp=
int responseCode=httpConnection.getResponseCode(); q}VdPt>X/
if(responseCode>=400) Ov?J"B'F
{ IOuqC.RJ}o
processErrorCode(responseCode); S1mMz i
return -2; //-2 represent access is error vW vu&3tx
} -]D/8,|s
VHl1f7%@H
A%$~
String sHeader; $8HiX6r
R(VOHFvW6
2ag8?#
for(int i=1;;i++) vxI9|i
{ PcU~1m1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0('ec60u
//Utility.log(in.readLine()); ,J!$Q0e
sHeader=httpConnection.getHeaderFieldKey(i); /"u37f?[^
if(sHeader!=null) Rq[d\BN0.d
{ Ur>1eN%9'
if(sHeader.equals("Content-Length")) C}Kl!
{ 7X/t2Vih@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FN=WU< 5
break; $GGaR x
} y*-_
} lG94^|U
else A( vdlj
break; N1Ag.
} 6b'.WB]-
} X~JP 1
catch(IOException e){e.printStackTrace ();} foQo`}"5
catch(Exception e){e.printStackTrace ();} 7>F{.\Z
+>vKI8g*RH
,bdjk(
Utility.log(nFileLength); 4m1r@ $
pxd=a!(
bSX/)')jU
return nFileLength; sTlel&
} ja';NIO-
!@8i(!xb
VK1B}5/
//保存下载信息（文件指针位置） }F_c0zM
private void write_nPos() KbvMp1'9P
{ ZCPUNtOl
try{ SFDTHvXu#_
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q zaD\^OF
output.writeInt(nStartPos.length); f6`GU$H
for(int i=0;i<nStartPos.length;i++) kv3Dn&<rJ
{ V<H9KA
// output.writeLong(nPos); Op?"G
output.writeLong(fileSplitterFetch.nStartPos); 31G0B_T
output.writeLong(fileSplitterFetch.nEndPos); Y6sX|~Zy
} p T8?z
output.close(); x}?<9(nE c
} Wx{E\ l
catch(IOException e){e.printStackTrace ();} y3s+.5;
catch(Exception e){e.printStackTrace ();} RE%f'y
} KBN% TqH|
{.{Wl,|7
|9c~kTjK
//读取保存的下载信息（文件指针位置） tULGfvp
private void read_nPos() bP9ly9FH
{ @3O)#r}\
try{ "yaxHd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SXOAa<u5
int nCount = input.readInt(); *<($.c
nStartPos = new long[nCount]; ^1bslCe
nEndPos = new long[nCount]; M }d:B)cz
for(int i=0;i<nStartPos.length;i++) M[YFyM(
{ \BXzmok
nStartPos = input.readLong(); +C{-s
nEndPos = input.readLong(); eNAxVF0
} HN{c)DIm]
input.close(); ~dRstH7u
} e;6KxvX~
catch(IOException e){e.printStackTrace ();} SE]5cJ'>
catch(Exception e){e.printStackTrace ();} UlE%\L0GD&
} EaO@I.[
=xI'|%
V>'
private void processErrorCode(int nErrorCode) +hmFFQQ}
{ @9gZH_ur>E
System.err.println("Error Code : " + nErrorCode); g8%O^)d=>
} = (F
-o6rY9\_!
-y+>^45
//停止文件下载 [fa4
public void siteStop() *n? 1C"l
{ {G:y?q'z
bStop = true; w!7\wI[
for(int i=0;i<nStartPos.length;i++) Y7VO:o
fileSplitterFetch.splitterStop(); 1jl!VU6
E6A"Xo
`S@TiD*
} )O~[4xV~
} S13cQ?4
//负责部分文件的抓取 GrL{q;IO
**FileSplitterFetch.java 'kZ,:.v
*/ xLz=)k[''
package NetFox; eyJ07
GlAI~\A
p?:5U[KM
import java.io.*; 1q;v|F
import java.net.*; Nujnm$!,Q
e{P v:jl
WKEb '^
public class FileSplitterFetch extends Thread { LmF,en5
\beO5]KS<
/9w>:i81
String sURL; //File URL !LI<%P)
long nStartPos; //File Snippet Start Position ~9dpB>+
long nEndPos; //File Snippet End Position RwWg:4
int nThreadID; //Thread's ID "#j}F u_!
boolean bDownOver = false; //Downing is over _95296
boolean bStop = false; //Stop identical DYD<?._I
FileAccessI fileAccessI = null; //File Access interface .w9LJ
BPba3G9H
\n)',4mY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Zh<;r;2
{ R2~Tr$:
this.sURL = sURL; iEr,ly
this.nStartPos = nStart; []>'Dw_r
this.nEndPos = nEnd; \2i7\U
nThreadID = id; rVYoxXv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >1~ /:DJ
} wSTulo:9
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S\e&xUA;|
public void run() xAQtX=FoX+
{ C9n%!()>
while(nStartPos < nEndPos && !bStop) .V?:&_}_I6
{ SAx9cjj+
]k0 jmE
x *eU~e_jP
try{ ,fVD`RR(W?
URL url = new URL(sURL); >gk_klLh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lx^ eaP5
httpConnection.setRequestProperty("User-Agent","NetFox"); ,kN;d}bg
String sProperty = "bytes="+nStartPos+"-"; #<im?
httpConnection.setRequestProperty("RANGE",sProperty); 6[> lzEZ
Utility.log(sProperty); !_<6}:ZB
%qP[+N&
7RAB"T;?Q
InputStream input = httpConnection.getInputStream(); ISbs l=F
//logResponseHead(httpConnection); &],uD3:5O
QHEtG2
kmI0V[Y
byte[] b = new byte[1024]; T~TP
int nRead; yB*,)x0 @
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \hB BG8=&
{ <uH8Fivb
nStartPos += fileAccessI.write(b,0,nRead); `FP?9R6Y
//if(nThreadID == 1) 6o3 bq|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mPV<a&U
} 6OES'3Cy
'|C3t!H`
&NE e-cb[
Utility.log("Thread " + nThreadID + " is over!"); X%1TsCKMj
bDownOver = true; )D)5 `n)
//nPos = fileAccessI.write (b,0,nRead); ^QB[;g.O
} D6sw"V#
catch(Exception e){e.printStackTrace ();} p*Bty@CRi
} hRcb}>pr
} c?p^!zG
U@lc1#
NR{wq|"
//打印回应的头信息 l\HdB"nT
public void logResponseHead(HttpURLConnection con) aER|5!7(2\
{ 9(CvGzco<
for(int i=1;;i++) |y\Km
{ (!os&/",
String header=con.getHeaderFieldKey(i); lq/2Y4LE)
if(header!=null) [m t.2.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pm&THd
Utility.log(header+" : "+con.getHeaderField(header)); Ac7^JXh%
else kX 1}/l
break; IUcL*
} NWBYpGZx
} d"$8-_K
CT|+?
Kz4S6N c
public void splitterStop() )s2] -n}W
{ =P-&dN
bStop = true; `+JFvn!
} 1SQATUV
!*IMWm>
~}/Dl#9R!
} l^B.iB
I$Nh|eM
o_b[*
/* cPGlT"
**FileAccess.java |m19fg3u
*//文件访问(定位，写) "cH RGJG#
package NetFox; <P9fNBGa
import java.io.*; Y4T")
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0P^h6Vat
public class FileAccessI implements Serializable{ 85{m+1O~
<_tmkLeZf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G4&s_M$
RandomAccessFile oSavedFile; DA=U=F
long nPos; W+nu=iQ!
r );R/)&
/YKd [RQ
public FileAccessI() throws IOException 9N]Xa
{ 7*'/E#M
this("",0); MfTLa)Rz
} #c!:&9oU
Nz{dnV{&x;
.J#'k+>
public FileAccessI(String sName,long nPos) throws IOException aD/Rr3v>
{ E$d3+``
oSavedFile = new RandomAccessFile(sName,"rw"); FoefBo?g65
this.nPos = nPos; (iIw}f)w
oSavedFile.seek(nPos); 0oe<=L]F
} .{Y;6]9[
Pg4&}bX:I
?5|;3N/zt
public synchronized int write(byte[] b,int nStart,int nLen) >&L|oq7$
{ Iw1Y?Qia
int n = -1; x^eu[olN
try{ l}{{7~C`
oSavedFile.write(b,nStart,nLen); a(Y'C`x
n = nLen; *2X6;~
} ~/:vr
catch(IOException e) h@)U,&
{ KuNLu31%
e.printStackTrace (); WSThhI
} +,Dc0VC?
x_PO;
q:{#kv8
return n; )!y>2$20 r
} 2FcL-?
wAMg"ImJ
(su,=Z
} " T(hcI
>nSsbhAe
~KK9aV{
/* -luQbGcT3
**SiteInfoBean.java gW,[X(
*/ a+h$u
package NetFox; <+8'H:wz
0V%c%]PH
^5 >e
public class SiteInfoBean { U}v`~'K
:I"CQ C[Z
E}^V@ :j>
private String sSiteURL; //Site's URL k(Yz2
private String sFilePath; //Saved File's Path xh6(~'$
private String sFileName; //Saved File's Name |9@,ri\'Rg
private int nSplitter; //Count of Splited Downloading File 0SpB2>_
h!"2Ux3!x
8K8u|]i
public SiteInfoBean() W?7l-k=S
{//nSplitter的缺省值为5 G1:}{a5i_
//default value of nSplitter is 5 EIi<g2pM(
this("","","",5); %lKw+D
} %zavSm"
S :HOlJze
,(jJOFf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {1GJ,['qL
{ ;qx#]Z0 <
sSiteURL= sURL; n}p G&&;q
sFilePath = sPath; NW|B|kc
sFileName = sName; e8a^"Z`a
this.nSplitter = nSpiltter; 6(|mdk`i
J,a&"eOZ
1-RY5R}VR
} mq:k|w^6
Xz]l#w4Pp
y@LImiRG
public String getSSiteURL() J%|?[{rO{'
{ U}2@
return sSiteURL; 7T[~~V^x
} , 3R=8
Sn:>|y~
a[{qb
public void setSSiteURL(String value) AR"2?2<mJ7
{ g`EZLDjt
sSiteURL = value; w0QtGQ|
} rcnH^P
_K5<)( )
2w>%-_]u+
public String getSFilePath() W 4{ T<
{ ET*A0rt
return sFilePath; YV>a 3
} FT).$h~+4
iIfiv<(ChM
IPot][ N>
public void setSFilePath(String value) tX*@r
{ B=Hd:P|
sFilePath = value; ]&'!0'3`
} o.s'0xP]
EPo)7<|>
ZbRRDXk!
public String getSFileName() )1<0c@g=
{ A#>wbHjWF
return sFileName; 5-dt0I@<
} g&RpE41x
"2e3 <:$
l;$F[/3a
public void setSFileName(String value) <O jK $KV
{ f/\!=sa:
sFileName = value; 8 Ku9;VEk
} N'1I6e"
*0U#Z]t
L F?/60
public int getNSplitter() _KRnx-
{ =lNW1J\SW
return nSplitter; V[ UOlJ
} @Z]0c=-+
+|?a7qM
&BVUK"}P
public void setNSplitter(int nCount) e\)%<G5
{ ui]iOp
nSplitter = nCount; q NGR6i
} %Z;RY5
} T! }G51
/N0mF< P
+o+f\!
/* A;!5c;ftj,
**Utility.java [bLKjD
*/ vbJ<|#|r-
package NetFox; 6/!:vsa"3
288mP]a(v_
O"9t,B>=i
public class Utility { zJ`u>:*$
,7nu;fOT[
(nqhX<T>
public Utility() =B&|\2`{)
{ (o>N*?,}
~|u;z,\
%6ckau1_;
} Y XhZWo{B
'O%*:'5k
//线程睡眠 HoBx0N9\2
public static void sleep(int nSecond) rpk8
{ GTs,?t16/
try{ tmGhJZ2j
Thread.sleep(nSecond); GEPWb[Oa
} `n+uA~
catch(Exception e) !&%KJS6p4
{ pI@71~|R
e.printStackTrace (); kn#?+Q
} 9WHE4'Sa
} l4gH]!/@
q\tr&@4iC
//日志 ?M90K)&g{
public static void log(String sMsg) +kI}O*s
{ (4Db%Iw
System.err.println(sMsg); za>%hZf\
} P, x"![6
M:O*_>KF
]W3u~T*
public static void log(int sMsg) df{?E):
{ n%r>W^2j
System.err.println(sMsg); lG6&uMvo
} Z%#e* O0
} )~M@2;@L
,]wab6sY
W *0!Z:?
/* tFcQ.1
**TestMethod.java ( w4XqVT
*/ m.P F'_)/
package NetFox; ]n=z(2Z9lD
?`TQ!m6y
II^Rp],>
public class TestMethod { ~U+<JC Z
h`Jc%6o
<mX5VGY9^
public TestMethod() J rK{MhO
{ ///xx/weblogic60b2_win.exe Eq@sU?j
try{ R14&V1 tZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >MJ%6A>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 58?WO}
SiteFileFetch fileFetch = new SiteFileFetch(bean); {F_>cyR
fileFetch.start(); *b;)7lj0h
} 2?(/$F9X,
catch(Exception e){e.printStackTrace ();} tE>FL
I N@ ~~
UXZ3~/L5 O
} )g=mv*9>
Qfeu3AT
9u~C?w
public static void main(String[] args) [\F:NLjiUy
{ 4][VK/v+
new TestMethod(); DN9x<%/-
} yO-2.2h
} 6rS ? FG=
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