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)); K9UWyM<(2C
} ;gW?Fnry;
for(int i=0;i<nEndPos.length-1;i++) p:qj.ukw
{ qCYXkZ%`
nEndPos = nStartPos[i+1]; ?;Ge/~QU5
} 2ZFp(e^%
nEndPos[nEndPos.length-1] = nFileLength; <k2]GI-}h
} 4Yl:1rz
} Z+x`q#ZQr
"ZFK-jn/
*mXs(u
//启动子线程 2o-Ie/"d\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TWJ%? /d
for(int i=0;i<nStartPos.length;i++) <7sGA{
{ MQGR-WV=5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6\?<:Qto
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]+i~Cbj
nStartPos,nEndPos,i); V$<5`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c*x5t"{
fileSplitterFetch.start(); W%cJ#R[o
} mw&)j R$&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~m.@{Do0p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); = eDi8A*~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fP:g}Z
nEndPos = " + nFileLength); KZSvT{
// fileSplitterFetch[nPos.length-1].start(); \LpR7D
(lVHKg&U[
o@KK/f
//等待子线程结束 4q\bnt
//int count = 0; R7d45Wl
//是否结束while循环 k),.
boolean breakWhile = false; 8z h{?0
$,~D-~-
i>68gfx
while(!bStop) 6S#e?>"+
{ Cl5l+I\1
write_nPos(); 8/dx)*JCq
Utility.sleep(500); %0!!998
breakWhile = true; $kef_*BQg
g",htYoEnj
{"uLV{d
for(int i=0;i<nStartPos.length;i++) B#T4m]E/
{ CQx#Xp>=s
if(!fileSplitterFetch.bDownOver) ub/9T-#l
{ C.[abpc
breakWhile = false; :_FnQhzg
break; MIJ^n(-G
} $kA'9Y
} plRBfw>]N
if(breakWhile) fGtUr_D
break; U- UD27
MM*B.y~TxZ
aIl}|n"
//count++; D 1Q@4 g
//if(count>4) Gb\Nqx(
// siteStop(); N%k6*FBp~
} >vPDF+u
Oist>A$Z
'518S"T @
System.err.println("文件下载结束！"); }j/($,
} Qt@_C*,P
catch(Exception e){e.printStackTrace ();} /Jjub3>Q
} o&GS;{Rs
*t JgQ[
s^{hdCCl67
//获得文件长度 s^@?+<4:
public long getFileSize() &G)I|mv
{ kf8-#Q/B
int nFileLength = -1; Nm.H
try{ 0Y_?r$M
URL url = new URL(siteInfoBean.getSSiteURL()); wE.CZ%f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,F,\bp}
httpConnection.setRequestProperty("User-Agent","NetFox"); ,dTRM
7S_rN!E1i*
ZH:-.2*cj
int responseCode=httpConnection.getResponseCode(); 6V"|
if(responseCode>=400) $?.0>0,<
{ "%o,P/<X
processErrorCode(responseCode); /A8ua=Kn
return -2; //-2 represent access is error ^u?#fLr
} KxZO.>,
OT*C7=
2qw-:
String sHeader; Ry@QJn I<
TSGJ2u5ie%
g>m)|o'
for(int i=1;;i++) /k$h2,O"*
{ .^aakM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rqi=AQ
//Utility.log(in.readLine()); gn2*'_V~3
sHeader=httpConnection.getHeaderFieldKey(i); $>PXX32
if(sHeader!=null) SXYH#p
{ o$*aAgS+
if(sHeader.equals("Content-Length")) q#{.8H-X'
{ 5`TbM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DChqcdx~~
break; BB x359
} ;_o1{?~
} }?KvT$s
else O_9M /[<
break; @/MI Oxg[
} !cLdoX
} OcA_m.
catch(IOException e){e.printStackTrace ();} eGwO!Lv}B
catch(Exception e){e.printStackTrace ();} #\|Ac*>
WH>=*\
<>n-+Kr
Utility.log(nFileLength); !2.(iuE
wzXIEWJ
7Ei,L[{\i#
return nFileLength; L701j.7"
} JPH! .@
R[C+?qux
zBQV2.@
//保存下载信息（文件指针位置） 'YKzs;y$
private void write_nPos() {\1:2UKkr
{ &kR*J<)V
try{ Su]@~^w
output = new DataOutputStream(new FileOutputStream(tmpFile)); YiO3.+H
output.writeInt(nStartPos.length); :w!A_~ w2
for(int i=0;i<nStartPos.length;i++) *1H8 &
{ ty"|yA
// output.writeLong(nPos); ?*)Q[P5
output.writeLong(fileSplitterFetch.nStartPos); "{;E+-/ aL
output.writeLong(fileSplitterFetch.nEndPos); kB)u@`</mV
} %ER"Udh
output.close(); uPT2ga]
} xU1_L*tu '
catch(IOException e){e.printStackTrace ();} Y>/T+ub
catch(Exception e){e.printStackTrace ();} qa\e`LD%Y
} !K8Kw W|X
]c9\[Kdq}H
F@tfbDO?
//读取保存的下载信息（文件指针位置） jIL+^{K<
private void read_nPos() pjN4)y>0
{ tD~ nPbbB
try{ gW5yLb_Vz$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6~!QibA|P
int nCount = input.readInt(); 0!Vza?9
nStartPos = new long[nCount]; y+aKk6(_W
nEndPos = new long[nCount]; Ka_g3
for(int i=0;i<nStartPos.length;i++) z/I\hC9i
{ 2il`'X
nStartPos = input.readLong(); +a'LdEp
nEndPos = input.readLong(); Ud_7>P$a
} YMU2^,3
input.close(); `0_,>Z
} qs%UJ0tR
catch(IOException e){e.printStackTrace ();} -U{CWn3G
catch(Exception e){e.printStackTrace ();} Y#5v5
} ~m'8<B5+
sXi~cfFaE
64L;np>
private void processErrorCode(int nErrorCode) 4;bc!> sfC
{ j8G$,~v
System.err.println("Error Code : " + nErrorCode); Eq?U$eE
} 3xz|d`A
T)I\?hqTB
x[y}{T
//停止文件下载 noso* K7
public void siteStop() L)n_ Q
{ ;nx.:f
bStop = true; @#p6C
for(int i=0;i<nStartPos.length;i++) I 6'!b/
fileSplitterFetch.splitterStop(); [}=a6Q>)
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O I0N(V
} R/xT.EQ(N
} zM(-f|wVI)
//负责部分文件的抓取 wmA TV/
**FileSplitterFetch.java nMJ(tQ
*/ e*yl_iW
package NetFox; D/VEl{ba-
X`(fJ',
lWn}afI
import java.io.*; ^`[<%.
import java.net.*; kLF~^/
cMrO@=b;
NM9,AG
public class FileSplitterFetch extends Thread { >,QCKZH
8`wKq6
9q+W>wt
String sURL; //File URL +w7U7" xQ
long nStartPos; //File Snippet Start Position % H<@Y$r
long nEndPos; //File Snippet End Position J(K/z,4h
int nThreadID; //Thread's ID -G~/ GO
boolean bDownOver = false; //Downing is over C}|.z
boolean bStop = false; //Stop identical @u`W(Ow
FileAccessI fileAccessI = null; //File Access interface tDavp:M1v
~;z] _`_Va
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d'&OEGb<
{ Bd 0oA )i
this.sURL = sURL; "iGQ1#6|d
this.nStartPos = nStart; X-X`Z`o
this.nEndPos = nEnd; P*B@it
nThreadID = id; Td|u-9OM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g\?v 5
} LEOri=?RF
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public void run() 9XYm8g'X
{ 1Jdx#K
while(nStartPos < nEndPos && !bStop) .zl[nx[9"D
{ k6J&4?xZ
^pH8'^n
gaxM#
try{ Dkb`_HI
URL url = new URL(sURL); }!{R;,5/n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !H@HgJ -
httpConnection.setRequestProperty("User-Agent","NetFox"); Wz#Cyjo
String sProperty = "bytes="+nStartPos+"-"; 1pg#@h[|t
httpConnection.setRequestProperty("RANGE",sProperty); :<bhQY
Utility.log(sProperty); MUsF
~Kt1%&3{a?
*r[V[9+y-D
InputStream input = httpConnection.getInputStream(); SD:D8"8
//logResponseHead(httpConnection); i-w$-2w
vb?.`B_>&
T9%|B9FeJ
byte[] b = new byte[1024]; )XavhS~Ff
int nRead; :hs~;vn)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _Y;tD
{ |&{S ~^$
nStartPos += fileAccessI.write(b,0,nRead); wggB^ }~
//if(nThreadID == 1) i!}6FBZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~-6_-Y|
} #) :.1Z?
#+p-
\/<VJB uV
Utility.log("Thread " + nThreadID + " is over!"); "^6Fh"]
bDownOver = true; q`/J2r+O
//nPos = fileAccessI.write (b,0,nRead); UO&$1rV
} &PRoT#,
catch(Exception e){e.printStackTrace ();} ohqThl
} D-LOjMe
} BCe'J!
{pH#zs4Y
.l_Nf9=
//打印回应的头信息 @L~erg>8=
public void logResponseHead(HttpURLConnection con) K$Vu[!l`
{ -JF^`hBD-
for(int i=1;;i++) G\BZ^SwE
{ n<j+KD#a
String header=con.getHeaderFieldKey(i); Q17dcgd
if(header!=null) ~?Ky{jah:^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QK+,63@D\=
Utility.log(header+" : "+con.getHeaderField(header)); x1#>"z7
else X.;VZwT+
break; i(;`x
} 4>0q0}J=5
} PBb&.<
lTqlQ<`V
G2kU_
public void splitterStop() 5[SwF&zZ
{ <C&|8@A0
bStop = true; #l4T/`u'9!
} Rv9jLH
i,*m(C@F}
T2<%[AF0
} lJ-PW\P
Na/Y1RW
y0mNDze
/* /9G72AD!
**FileAccess.java n_km]~
*//文件访问(定位，写) A)sYde(
package NetFox; 5\bGCf
import java.io.*; IB[$~sGe
}psRgF
'1ySBl1>
public class FileAccessI implements Serializable{ NgGMsE\C}
50N4J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;z4F-SYQ
RandomAccessFile oSavedFile; ]q%r2 (y,k
long nPos; k(dakFaC^
P+hcj p*
bJ!\eI%ld
public FileAccessI() throws IOException 3MQZ)!6
{ ~%/Rc`
this("",0); gfg,V.:
} ):! =XhQ
aP
c,2& -T}
public FileAccessI(String sName,long nPos) throws IOException f*XCWr
{ 29RP$$gR
oSavedFile = new RandomAccessFile(sName,"rw"); +r8bGS]ki
this.nPos = nPos; `sYFQ+D#O
oSavedFile.seek(nPos); W%g*sc*+
} vAUt~X"
U8Y%rFh1
%vJHr!x
public synchronized int write(byte[] b,int nStart,int nLen) /IUu-/ D
{ Zok{ndO@|f
int n = -1; `uMEK>b
try{ /e'3\,2_
oSavedFile.write(b,nStart,nLen); 'V:Q :
n = nLen; Q4"\k. ?
} t_3j_`
catch(IOException e) yV{B,T`W
{ d+JK")$9C
e.printStackTrace (); `$6o*g>:
} lhN@,q
S 5S\zTPIf
p`Pa;=L
return n; Ap dXsL
} 7=6:ZSI
I@'[>t
\Z]+j@9
} ANhtz1Fl
7]h%?W!
b' o]Y
/* ~R!1{8HP
**SiteInfoBean.java i 9) Gt
*/ .Mq#88o.*
package NetFox; )/;KxaKt
T`bYidA
o^"+X7)
public class SiteInfoBean { ;'"'|} xn
Dh I{&$O/
E`IXBI
private String sSiteURL; //Site's URL m!V,W*RNr
private String sFilePath; //Saved File's Path pi"H?EHk
private String sFileName; //Saved File's Name ;.>*O oe&
private int nSplitter; //Count of Splited Downloading File ]&*POri&
8 1,N92T5
MpCPY"WLL
public SiteInfoBean() Qa{5]+E
{//nSplitter的缺省值为5 >ED;_L*_o
//default value of nSplitter is 5 0]DOiA
this("","","",5); Y+?QHtZL
} 8Y`Lq$u
dfDjOZSL
]>n{~4a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V*p[6{U0
{ E)v~kC}7.
sSiteURL= sURL; _{*} )&!M
sFilePath = sPath; 5GsmBf$RUb
sFileName = sName; }LUvh
this.nSplitter = nSpiltter; W5R/Ub@g
CNB weM
^{Y,`F
} |+cz\+
;d?BVe?
bxXpw&
public String getSSiteURL() ,1-%C)
{ ,1]UOQ>AP
return sSiteURL; '@n"'vks(\
} K; #FU
e{)giJY9
odP<S.
public void setSSiteURL(String value) %'2P4(
{ mv9D{_,pD
sSiteURL = value; CsR[@&n'
} +t7HlAXB#
9{pT)(Wnb
|_53So:g
public String getSFilePath() ;}B=g/C
{ l6'KIg
return sFilePath; WIWo4[(
} v^9eTeFO
EjPR+m
rZUTBLZ`j
public void setSFilePath(String value) dDcQSshL
{ X@~/.H5
sFilePath = value; m(f`=+lqI`
} htB2?%S=T
4H 6t" X
O"\4[HE^
public String getSFileName() 0akJv^^D
{ XT^=v6^H
return sFileName; dsIbr"m
} jOhAXe;~X{
tB;PGk_6
ra~=i|s
public void setSFileName(String value) -^NW:L$|
{ FBE|pG7
sFileName = value; BA a:!p
} cqU6 Y*n
pj%]t
ww|fqx?
public int getNSplitter() AO<T6VK
{ veDv14
return nSplitter; B7Ket8<J
} sI\NX$M
jdG'sITv
=p|IWn{P
public void setNSplitter(int nCount) GW {tZaB
{ #19O5
nSplitter = nCount; s(_z1
} R&1>\t
} WrP+n
zFOtOz`9H
'e:4
/* bfeTf66c
**Utility.java 2IJniS=[>
*/ Ry[7PLn]
package NetFox; MTt8O+J?P~
9>{ml&$
Kmx4bp4
public class Utility { P)VQAM
/yU#UZ4;
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public Utility() f['I4 /o
{ @ws&W=NQ
C32*RNG?U
W. d',4)
} |HAbZd7PG
i:Y5aZc/Ds
//线程睡眠 54{E&QvL8o
public static void sleep(int nSecond) *~U*:>hS
{ &CRgi488b
try{ TT3 6Y
Thread.sleep(nSecond); L%[>z'Zp
} lOA EM
catch(Exception e) 2KO`+
{ jNbVp{%/S}
e.printStackTrace (); E$_zBD%
} \e'Vsy>q
} iB99.,o-&
m|JA}&A
//日志 o(}%b8 K
public static void log(String sMsg) Z|KDi `S
{ zWPX
System.err.println(sMsg); _zbIS&4
} BN(=LQ2["
"+2Cs
lpPPI+|4N
public static void log(int sMsg) /0>'ZzjV,
{ {1=|H$wKg
System.err.println(sMsg); |L*=\%t8
} 3AENY@*
} %J'/cmR&
].Bx"L!B
{a\! 1~
/* hrJ(][8
**TestMethod.java Q(A$ >A
*/ YeT{<9p
package NetFox; x?A<X2
^?]-Q*w3Qs
Z[&FIG%tV
public class TestMethod { ]}Ys4(}
o6w8Y/VPu
"N'W~XPG
public TestMethod() :G98uX t
{ ///xx/weblogic60b2_win.exe yX*$PNL5w
try{ izcjI.3e,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *[i49X&rd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RIUJX{?
SiteFileFetch fileFetch = new SiteFileFetch(bean); mVS^HQ:
fileFetch.start(); m<#^c?u
} THy?Y
catch(Exception e){e.printStackTrace ();} uDJ;GD[yc
H;<>uELie
du'`&{_/
} gREk,4DAv
SHSfe{n
&Qv HjjQ?u
public static void main(String[] args) `<~=6H
{ vP#*if[V5
new TestMethod(); "~.4z,ha
} zp:QcL"
} $"( 15U
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