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)); 7;9 Jn
} -"6Z@8=
for(int i=0;i<nEndPos.length-1;i++) +1nzyD_E
{ a FL;E
nEndPos = nStartPos[i+1]; 1#KBf[0
} e.WKf,e"X
nEndPos[nEndPos.length-1] = nFileLength; yJW/yt.l
} :6J&%n
} <72q^w
#ri;{d^6
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//启动子线程 Y)2#\ F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yof8LWXx
for(int i=0;i<nStartPos.length;i++) NUFW SL>
{ 6&o?#l;|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M9~6ry-_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lk.tEuj=82
nStartPos,nEndPos,i); .'b|pd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6w~Cyu4Ov
fileSplitterFetch.start(); Hu+GN3`sx^
} t==\D?Rt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >D%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #^{%jlmHxJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", aSMoee@!
nEndPos = " + nFileLength); C{~O!^2G
// fileSplitterFetch[nPos.length-1].start(); \027>~u {
j/;wxKW
fr`Q 5!0
//等待子线程结束 ~ ReX$9
//int count = 0; *U-:2uf
//是否结束while循环 mbns%%GJU
boolean breakWhile = false; 2I283%xr
0Oa&vx
n=?wX#rEC#
while(!bStop) "R"{xOQl
{ 'Y/kF1,*
write_nPos(); r7FJqd
Utility.sleep(500); GT\yjrCd
breakWhile = true; w c
WF:4p]0~)
F\^\,hy
for(int i=0;i<nStartPos.length;i++) rBOH9L
{ n6G&c4g<"
if(!fileSplitterFetch.bDownOver) #8~ygEa}
{ zB/VS_^^W:
breakWhile = false; DF UTQ:N
break; *qu5o5Q
} O*.n;_&
} .PV(MV
if(breakWhile) u%lUi2P2E
break; ?#Y:2LqPC
5 D=r7
)5n:UD{f[#
//count++; TZGk[u^*
//if(count>4) /8!n7a7
// siteStop(); K]uH7-YvL/
} ^qi+Y)dU|
pjl>ZoOM
n_:EWm$\
System.err.println("文件下载结束！"); +25=u|#4r
} 9Ofls9]U
catch(Exception e){e.printStackTrace ();} *}T|T%L4)
} X8ZO } X
h-RhmQA=Iz
zR<fz
//获得文件长度 aGfp"NtL
public long getFileSize() Ftd,dqd
{ ,LP^v'[V7
int nFileLength = -1; hg#O_4D
try{ Go^TTL
URL url = new URL(siteInfoBean.getSSiteURL()); W-gu*iZ6&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LAY:R{vI
httpConnection.setRequestProperty("User-Agent","NetFox"); M<*WC{
T\(k=0RM
0TSB<,9a[
int responseCode=httpConnection.getResponseCode(); Yi)s=Q:
if(responseCode>=400) <=D a
{ 13w(Tf
processErrorCode(responseCode); SH#*Lc
return -2; //-2 represent access is error vU5}E\Ny
} tbiM>qxB
O|)b$H_
Lq1?Y
String sHeader; pT3icy!A=
gujP{Z
eO(U):C2
for(int i=1;;i++) !c{F{t-a
{ Pr(@&:v:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \G7F/$g
//Utility.log(in.readLine()); %?aq1 =B
sHeader=httpConnection.getHeaderFieldKey(i); UV0[S8A
if(sHeader!=null) -u4")V>
{ al-rgh
if(sHeader.equals("Content-Length")) ^Y+Lf]zz*
{ iU37LODa2T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mo] l_'
break; xy4+ [u
} |2@*?o"ll
} J|DZi2o
else %2\tly!{ %
break; j*Pq<[~
} ;b~\[
} yz=X{p1
catch(IOException e){e.printStackTrace ();} \!BVf@>p%
catch(Exception e){e.printStackTrace ();} s.Bb@Jq
f7][#EL
Qubu;[0+a
Utility.log(nFileLength); qIQRl1Tw;V
]d@>vzCO
X!/Sk1
return nFileLength; Iz#4!E|<
} 3\Q9>>
z\A ),;
Z+J4q9^$
//保存下载信息（文件指针位置） 5Gy#$'kdf
private void write_nPos() eh `%E0b}
{ G$MEVfd"
try{ L YF|
output = new DataOutputStream(new FileOutputStream(tmpFile)); &JqaIJh
output.writeInt(nStartPos.length); 1ONkmVtL
for(int i=0;i<nStartPos.length;i++) oD9n5/ozo
{ nHk^trGm
// output.writeLong(nPos); u;-fG9xs
output.writeLong(fileSplitterFetch.nStartPos); I4?oBq
output.writeLong(fileSplitterFetch.nEndPos); 3N|z^6`#
} "O<ETHd0
output.close(); o!KDeY
} ,>S7c
catch(IOException e){e.printStackTrace ();} W_JO~P
catch(Exception e){e.printStackTrace ();} 2wIJ;rh
} 7<;oz30G!L
/B~[,ES@1
6X%g-aTs
//读取保存的下载信息（文件指针位置） 'u;O2$
private void read_nPos() /G'3!S
{ ?`rAO#1
try{ L}Y.xi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 62qjU<Z
int nCount = input.readInt(); vBl:&99[/
nStartPos = new long[nCount]; SnmUh~`L~
nEndPos = new long[nCount]; ~r5S{&
for(int i=0;i<nStartPos.length;i++) UWvVYdy7
{ ~<n.5q%Z
nStartPos = input.readLong(); Dz6xx?
nEndPos = input.readLong(); .Lna\Bv
} uoI7' :Nv
input.close(); > ]^'h
} x'I!f? / &
catch(IOException e){e.printStackTrace ();} ]>VG}e~b
catch(Exception e){e.printStackTrace ();} &~Hed_
} jTcv&`fAz
Bso#+v5
c:Nm!+5_(
private void processErrorCode(int nErrorCode) LsuOmB|^
{ HT.*r6Y>g
System.err.println("Error Code : " + nErrorCode); " L`)^
} KaNs>[a8
CC`_e^~y=F
BA]$Fi.Mw
//停止文件下载 lFyDH{!
public void siteStop() \H@1VgmR;
{ Zob/H+]
bStop = true; ]$[sfPKA
for(int i=0;i<nStartPos.length;i++) F`QViZ'n>#
fileSplitterFetch.splitterStop(); K8sRan[4}
T+F]hv'
Ec@n<KK#
} *(F`NJ 3
} yQD>7%x
//负责部分文件的抓取 5dj@N3ZX7;
**FileSplitterFetch.java akzGJ3g
*/ W8^m-B&
package NetFox; >Q\Kc=Q|
7~mhWPzMwB
#4msBax4
import java.io.*; PC#^L$cg}
import java.net.*; l[38cF
=Xh)34q
q*l4h u%3
public class FileSplitterFetch extends Thread { T$xBH
`x9Eo4(/
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String sURL; //File URL ecghY=%
long nStartPos; //File Snippet Start Position rG-T Dm
long nEndPos; //File Snippet End Position _F;v3|`D@<
int nThreadID; //Thread's ID k2U*dn"9U
boolean bDownOver = false; //Downing is over `r`8N6NQ&]
boolean bStop = false; //Stop identical /*mF:40M;
FileAccessI fileAccessI = null; //File Access interface (jM0YtrD
*9aJZWf>V
*j%x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;Y?MbD
{ hzqJ!
this.sURL = sURL; uZ!YGv0^
this.nStartPos = nStart; !*N9PUM
this.nEndPos = nEnd; s<9g3Gh
nThreadID = id; P=QxfX0B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0ns\:2)cEB
} *2G6Q gF
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+xFn~b/
public void run() Z7;V}[wie
{ &|/_"*uM
while(nStartPos < nEndPos && !bStop) /T w{JO#Q
{ 4ba*Nc*Yc
ju"z
2r, c{Ah@D
try{ 35<A:jKS
URL url = new URL(sURL); jx: IK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UerbNz|
httpConnection.setRequestProperty("User-Agent","NetFox"); >HP `B2Q H
String sProperty = "bytes="+nStartPos+"-"; 7*!7EBb
httpConnection.setRequestProperty("RANGE",sProperty); qO#3{kW
Utility.log(sProperty); \Z[1m[{
~KBa-i%o
j9p6rD
InputStream input = httpConnection.getInputStream(); IOy0WHl|
//logResponseHead(httpConnection); aSzI5J]/=
T8XrmR&?PX
uUH4vUa
byte[] b = new byte[1024]; DXs an
int nRead; ar3L|MN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NAGM3{\5v$
{ //R"ZE@d\
nStartPos += fileAccessI.write(b,0,nRead); 2}hJe+#v
//if(nThreadID == 1) f9.?+.^_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ON :t"z5
} @!sK@&ow@%
17LhgZs&
6d-\+t8
Utility.log("Thread " + nThreadID + " is over!"); VmS_(bM
bDownOver = true; wZqYtJ
//nPos = fileAccessI.write (b,0,nRead); YKyno?m
} ,2@o`R.27
catch(Exception e){e.printStackTrace ();} uO%0rKW
} %~u]|q<{
} cU1o$NRx
Y t(D
n(:<pz
//打印回应的头信息 b9bIvjm_
public void logResponseHead(HttpURLConnection con) EL 5+pt
{ -ss= c#
for(int i=1;;i++) V=O52?8
{ M(%H
String header=con.getHeaderFieldKey(i); FK%b@/7s~
if(header!=null) m'o dVZ7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aJu&h2G
Utility.log(header+" : "+con.getHeaderField(header)); broLC5hbQU
else LrB 0x>
break; E&M(QX5
} CIudtY(:
} MpV<E0CmE
(MwRe?Ih
gq=t7b
public void splitterStop() honh'j
{ PDNl]?
bStop = true; ]C_+u_9
} (b&g4$!x&5
E C#0-,z
,f }$FZ
} Y|Iq~Qy~
Y;i=c6
2+1ybOwb
/* '&IGdB I
**FileAccess.java ?Ga8.0Z~KT
*//文件访问(定位，写) s9- qR_
package NetFox; i]8O?Ab>?
import java.io.*; Pv -4psdw
0TU3 _;o
a"Qf
public class FileAccessI implements Serializable{ I)HO/i6>3
"Q?+T:D8|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Knwy%5.Z
RandomAccessFile oSavedFile; /%@;t@BK4
long nPos; 6v`3/o
D|uvgu2
,H=k5WA4m
public FileAccessI() throws IOException F};R
{ N>mW64_H)
this("",0); I)rnF
} dGKo!;7{
VjQ&A#
EX,>V,.UV
public FileAccessI(String sName,long nPos) throws IOException dNACE*g;q
{ '$ei3
oSavedFile = new RandomAccessFile(sName,"rw"); xyL"U*
this.nPos = nPos; 05d0p|},
oSavedFile.seek(nPos); 0 R6:3fV6R
} IJ^~,+
65EMB%
`Ba]i)!
public synchronized int write(byte[] b,int nStart,int nLen) h"FI]jK|}
{ ]#:WL)@
int n = -1; "\|P6H
try{ 0Lo8pe`DH
oSavedFile.write(b,nStart,nLen); ]!/
n = nLen; #p}GWS)
} 4BCPh:
catch(IOException e) +x]/W|5
{ TgiZ % G
e.printStackTrace (); IO)B3,g
} +_GS@)L`%
!"^Zr]Qt+\
b\P:a_vq
return n; =%<=Bn
} 7^dr[.Q[*
{&5lZ<nu8A
}c/p;<
} VN`.*B|9[
/U;j-m&
ifDWN*k6
/* ~[;r) g\
**SiteInfoBean.java .a4,Lr#q.
*/ JK$3qUDnI
package NetFox; P$EiD+5#z
K43%9=sM
64B.7S88
public class SiteInfoBean { J"aw 1
$Q*R/MY
PUR,r%K`
private String sSiteURL; //Site's URL g,,wG k
private String sFilePath; //Saved File's Path M9iX_4
private String sFileName; //Saved File's Name 8iIp[9~=
private int nSplitter; //Count of Splited Downloading File q`xc h[H
'K7\[if{
8~Kq"wrbu
public SiteInfoBean() Q(& @ra!{
{//nSplitter的缺省值为5 _vTr?jjfK
//default value of nSplitter is 5 {$8+n::
this("","","",5); p/Pus;*s
} yCQvo(V[F
sxT&T=7
I=!kPuw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $Cz2b/O
{ ~.T|n =
sSiteURL= sURL; h*Fv~j'p
sFilePath = sPath; [* <x)
sFileName = sName; mG~kf]Y
this.nSplitter = nSpiltter; Lm[,^k
?t'V5$k\
B_[efM<R$
} %9cT#9!7
}u8(7
7r;16"
public String getSSiteURL() y8YsS4E^Q
{ ~vXbh(MX
return sSiteURL; \ ca<L
} eha|cAq
w"{DLN[Qw
a3 }V/MY
public void setSSiteURL(String value) @&?(XY 'M%
{ P!79{8
sSiteURL = value; qur2t8gnxq
} C>|.0:[%
o< @![P
G2|jS@L#
public String getSFilePath() '~Y@HRVL@|
{ Krae^z9R
return sFilePath; DQGrXMpV0
} ~u&gU1}
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;t0q ?9
public void setSFilePath(String value) PA'&]piPl:
{ Nvd(?+c
sFilePath = value; 5n?P}kca)
} 4s7 RB
p6%Vf
i D9 */
public String getSFileName() W{-g?)Tou
{ h/n(
return sFileName; y"yo\IDW
} +j{Cfv$do
|Y K,&
$z[S0Cm
public void setSFileName(String value) JlYZ\
{ P!]uJ8bi
sFileName = value; ^i|R6oO_5
} 8xENzTR
>Lo\?X~
1(@$bsgu2
public int getNSplitter() G%sq;XT61
{ d3:GmB .
return nSplitter; JaUzu3*=
} X7!q/1$J
TR3U<:
.=;IdLO,Bf
public void setNSplitter(int nCount) 4|K\pCw
{ 0BDw}E\
nSplitter = nCount; ]mMJ6n
} HaVhdv3L
} 4-.W~C'Q
s$Vv
K.xABKPVc
/* 4`i8m
**Utility.java 8;?4rrS
*/ J$51z
package NetFox; #DgHF*GG+>
-Fd&rq:GB(
0Ncpi=6
public class Utility { > T*`Y0P
C7S\4rDJ
^:-GPr
public Utility() ;~<To9O
{ ^OiL&p;r
J- S.m(
#B5,k|"/,M
} ?Ujg.xo\
K\2{SjL:B
//线程睡眠 K#+?oFo:
public static void sleep(int nSecond) l$/pp
{ SyVGm@
try{ ??"_o3
Thread.sleep(nSecond); nx'c=gp
} sm-[=d%@L
catch(Exception e) bvtpqI QZ
{ '|4+<#
e.printStackTrace (); O#U maNj/
} 5VV}wR
} @N4~|`?U
yus3GqPI
//日志 a%r!55.
public static void log(String sMsg) #`u}#(
{ S[K5ofV
System.err.println(sMsg); w5 .^meU
} ]B3](TH"
Z i6s0Uck
g.&B8e
public static void log(int sMsg) ,m<YSMKX
{ :dt[ #
System.err.println(sMsg); 59oTU
} vb=]00c
} {\(G^B*\
yq-~5ui
,4H? +|!
/* jg?UwR&
**TestMethod.java `9r{z;UQ
*/ #p(c{L!
package NetFox; @l CG)Ix<
dq '2y
3wv@wqx
public class TestMethod { XKTDBaON
P7-k!p"
y8$3kXh
public TestMethod() Gt&yz"?D
{ ///xx/weblogic60b2_win.exe Ixn|BCi60A
try{ ?V2P]|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,w~3K%B4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]ltCJq
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6>)fNCe`
fileFetch.start(); aA4RC0'
} j9k:!|(2'
catch(Exception e){e.printStackTrace ();} zn>lF
sc]#T)xG
/ <(|4e
} 'b.jKkW7
f$>_>E
x~5,v5R^]
public static void main(String[] args) us.[wp'Sh
{ Tg^8a,Lt
new TestMethod(); KRxJ2
} 1<vJuF^
} #+o$Tg
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