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)); /e{Oqhf[n
} ( v ~/glf
for(int i=0;i<nEndPos.length-1;i++) Z^GriL
{ #2HygS
nEndPos = nStartPos[i+1]; aeBth{
} 4VU5}"<
nEndPos[nEndPos.length-1] = nFileLength; 'OX6eY5
} J?%D4AeS]v
} H V
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MB"?^~Sm
//启动子线程 Va*Uwy?x/)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s9[v_(W
for(int i=0;i<nStartPos.length;i++) .=@M>TZM
{ dqKTF_+VhA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Qc^A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), & vLX
nStartPos,nEndPos,i); 3?5 ~KxOE(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J$WIF&*0@
fileSplitterFetch.start(); ^jmnE.8R
} ]&G5/]f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *iC t4J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B-&J]H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Cq(Xa-
nEndPos = " + nFileLength); Y6D=tb
// fileSplitterFetch[nPos.length-1].start(); ryn)
=v;-{oN!
ZA9']u%EJ
//等待子线程结束 W>DpDrO4ml
//int count = 0; nev*TYY?A
//是否结束while循环 }lxvXVc{I
boolean breakWhile = false; m1[QD26
T:!sfhrZ~<
,<vrDHR
while(!bStop) "]NQTUb;
{ D 1hKjB&
write_nPos(); 'Yd%Tb|*
Utility.sleep(500); `jZX(H
breakWhile = true; MZd\.]G@
*UyV@
/e7'5#v
for(int i=0;i<nStartPos.length;i++) /t9w%Y
{ 4 ^+hw;
if(!fileSplitterFetch.bDownOver) ASYUKh,h
{ vSnb>z1
breakWhile = false; 93!a
break; X ]a>
} .y\HQ^j
} _E30t( _.
if(breakWhile) k]>k1Mi=
break; ;Q"F@v}18
Czci6Lz
Sm Ei _u]'
//count++; f<}!A$wd
//if(count>4) n]$vCP
// siteStop(); #VO2O0GR
} eLC&f}
C3b'Q
RV$+g.4
System.err.println("文件下载结束！"); "FXS;Jf
} tAC,'im:*
catch(Exception e){e.printStackTrace ();} FI/YJ@21
} zhCI+u4/qz
)-QNWN H
@B'Mu:|f
//获得文件长度 W8P**ze4)
public long getFileSize() R Nv<kw
{ *g,?13Q_
int nFileLength = -1; ZK ?x_`w
try{ R_N<j
URL url = new URL(siteInfoBean.getSSiteURL()); nEp'l.T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |,7J!7T(I
httpConnection.setRequestProperty("User-Agent","NetFox"); ILO+=xU
LQh\j|e9
Fd\XDc[g
int responseCode=httpConnection.getResponseCode(); v]BQIE?R /
if(responseCode>=400) JyqFFZ&
{ h#n8mtt&i
processErrorCode(responseCode); ;OPCBdr
return -2; //-2 represent access is error Z*TW;h0ZQ3
} {fb~`=?
j0%0yb{-^
TcP1"wc
String sHeader; dI 5sqM:
/-hF<oNQ
L|2COX
for(int i=1;;i++) dikWk
{ dq8 /^1P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p;7 4+q
//Utility.log(in.readLine()); 23f[i<4e
sHeader=httpConnection.getHeaderFieldKey(i); PPqTmx5S
if(sHeader!=null) j^ _I{
{ xk*3,J6BK
if(sHeader.equals("Content-Length")) !Q(xOc9>Ug
{ }g*-Ty
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kr*c?^b
break; QB.'8B_
} lQsQRp
} B![5+
else E&>,B81
break; ommKf[h%i
} !U#++Zig%
} x7@WWFF>
catch(IOException e){e.printStackTrace ();} r~}}o o4K
catch(Exception e){e.printStackTrace ();} &CL|q+-
ZM vTDH!
6|KX8\,A@
Utility.log(nFileLength); _M&.kha
bg,}J/
ii;WmE&
return nFileLength; |tg?b&QR
} |x6mkSf]ke
8Wj=|Ow-q
NVjJ/
//保存下载信息（文件指针位置） }m9LyT=~$
private void write_nPos() ;/V@N |$n
{ ~^^ey17
try{ N-rmk
output = new DataOutputStream(new FileOutputStream(tmpFile)); )RYnRC#O
output.writeInt(nStartPos.length); Z0=m:h
for(int i=0;i<nStartPos.length;i++) L, {rMLM%
{ Y/S3)o
// output.writeLong(nPos); $CmX &%L=
output.writeLong(fileSplitterFetch.nStartPos); p0rwiBC=q
output.writeLong(fileSplitterFetch.nEndPos); @1F'V'
} >$mSFJz5S
output.close(); $&8h=e~]-
} (J*w./
catch(IOException e){e.printStackTrace ();} )zXyV]xe
catch(Exception e){e.printStackTrace ();} Y(y9l{'
} (oXN>^-D
VWshFI
DVhTb
//读取保存的下载信息（文件指针位置） 1qC:3 ;P
private void read_nPos() mbBRuPEa=u
{ R1.sq(z`
try{ Uxemlp%%*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5b#6 Y
int nCount = input.readInt(); qP"JNswI_
nStartPos = new long[nCount]; X[Ek'=}
nEndPos = new long[nCount]; =4e=wAO(i
for(int i=0;i<nStartPos.length;i++) -L9R&r#_e
{ 8'lhp2#h
nStartPos = input.readLong(); <KwK tgzs
nEndPos = input.readLong(); Uk:.2%S2
} cU*lB!
input.close(); z`/.v&<>V
} #Q3PzDfj
catch(IOException e){e.printStackTrace ();} RW7oL:$dt
catch(Exception e){e.printStackTrace ();} %?f:"
} $a^isd4
$G_Q`w=jM
g`OOVaB
private void processErrorCode(int nErrorCode) -(w~LT$ "
{ zw:C*sY
System.err.println("Error Code : " + nErrorCode); ]zyX@=mM
} bw<w u}ED
OF&h=1De,
ZCBPO~&hO'
//停止文件下载 F:J7|<J^F
public void siteStop() ^W"Q(sh
{ f9,EWuQNS
bStop = true; ^QAiySR`0
for(int i=0;i<nStartPos.length;i++) JblmXqtC
fileSplitterFetch.splitterStop(); n`)7Y`hBhP
.H^P2tp
C6d]tLE
} 'yd@GQM&
} ~"0@u
//负责部分文件的抓取 -2&i)S0R
**FileSplitterFetch.java JT|u;Z*n
*/ ?{: D,{+
package NetFox; HRV*x!|I
,<3uc
_IL2-c8
import java.io.*; 3u*hTT
import java.net.*; wm=RD98
kwHqvO!G
VkpHzr[k
public class FileSplitterFetch extends Thread { k\pDJ7wF^
Mi}I0yhVm
5_)@B]~nM
String sURL; //File URL 3eTrtCe$
long nStartPos; //File Snippet Start Position Znta#G0
long nEndPos; //File Snippet End Position 'e]HP-Y<
int nThreadID; //Thread's ID n}A?jOSAe
boolean bDownOver = false; //Downing is over T|@#w%c''
boolean bStop = false; //Stop identical rKzlK 'U
FileAccessI fileAccessI = null; //File Access interface #+"4&:my
85D^@{
q[G/}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #%^\\|'z
{ (`6%og#8
this.sURL = sURL; B:-U`CHHQ
this.nStartPos = nStart; ] *-;' *
this.nEndPos = nEnd; A)Qh
nThreadID = id; Kej|1g1f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y}LLOj@L
} tqf&N0*
0||"r&:X
4;C*Fa
public void run() dC`tN5
{ _1sMYhI
while(nStartPos < nEndPos && !bStop) L)F1NuR
{ ]4Y/xi-
!:"-:O}>=,
lc[XFc
try{ a}KK{Vqo`
URL url = new URL(sURL); k&)K(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CV&zi6
httpConnection.setRequestProperty("User-Agent","NetFox"); mX&xn2}qZ"
String sProperty = "bytes="+nStartPos+"-"; P8wy*JvT
httpConnection.setRequestProperty("RANGE",sProperty); ptpW41t}^
Utility.log(sProperty); |3{+6cg
tAqA^f*{
~BZXt7DE
InputStream input = httpConnection.getInputStream(); j z~[5m}J
//logResponseHead(httpConnection); $n= O
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s`hav
byte[] b = new byte[1024]; J&eAL3"GF
int nRead; N = LM?(H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9Ct_$.Q.
{ 47IY|Jdz
nStartPos += fileAccessI.write(b,0,nRead); r6`\d k
//if(nThreadID == 1) m0A#6=<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i&`!|X-=R
} fVe@YqNa
I%@e@Dm,h
nr OqH
Utility.log("Thread " + nThreadID + " is over!"); k(P3LJcYQ
bDownOver = true; -bypuMQ-p
//nPos = fileAccessI.write (b,0,nRead); *URdd,){i
} eZg$AOpU
catch(Exception e){e.printStackTrace ();} EeCFII
} v&fGCD\R
} pOm@b`S%
2;G98H
P,i"&9 8
//打印回应的头信息 G0}Dq MTi
public void logResponseHead(HttpURLConnection con) eC~jgB
{ U98_M)-%&
for(int i=1;;i++) `=79i$,,t
{ -!cIesK;<
String header=con.getHeaderFieldKey(i); !!FR[NK
if(header!=null) 9\v.qo.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~m=$VDWm
Utility.log(header+" : "+con.getHeaderField(header)); 0[/vQ+O]2
else -kl;!:'.3
break; 14H'!$
} nbGoJC:U
} 6xHi\L
:zlpfm2
Ah-8"`E
public void splitterStop() xf/m!b"p
{ Fn!SGX~kx$
bStop = true; ibJl;sJ
} 7JI:=yY!>:
!z MDP/V
b^ sb]bZW
} zmI5"K"'F
XA1f' Kk
JA`H@qE
/* p1D()-
**FileAccess.java 9? 2
*//文件访问(定位，写) lUv=7" [
package NetFox; 1}!L][(
import java.io.*; P-'_}*wxi
"cMNdR1^,y
qD-fw-,:
public class FileAccessI implements Serializable{ [ ?iqqG.
Seda}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $n-Af0tK
RandomAccessFile oSavedFile; /b#q*x-b
long nPos; txq~+'A:+
mV?&%>*(f
rJQ=9qn\
public FileAccessI() throws IOException Jx$iwu
{ \jyjQ,v)
this("",0); =&Xdm(
} 0|XKd24BN
b`CWp;6Y
; 0ko@ \Lq
public FileAccessI(String sName,long nPos) throws IOException DyfsTx
{ Mra35
oSavedFile = new RandomAccessFile(sName,"rw"); F;u_7OM
this.nPos = nPos; x=]S.XI
oSavedFile.seek(nPos); -U-P}6^
} 5M:D?9E+
ES}. xZ#~
CISO<z0
public synchronized int write(byte[] b,int nStart,int nLen) *N F$1
{ 3qi_]*dD
int n = -1; Es.nHN^]%K
try{ Au.:OeJm
oSavedFile.write(b,nStart,nLen); I@\+l6&#;
n = nLen; 5G(E&>~
} =eBmBn
catch(IOException e) z/7$NxJH
{ 3;_ n{&
e.printStackTrace (); -(#-I$z
} |~K(F<;j
oM,- VUr
CPviR<ms_
return n; NTmi 2c
} WUEHB
dMvp&M\\'
nY_?Jq
} VWi2(@R^
!tNd\}@
T3N"CUk
/* zO~9zlik
**SiteInfoBean.java +e P.s_t
*/ por/^=e{Y
package NetFox; qX#MV>1
9+qOP>m
>jx.R
public class SiteInfoBean { 3fr^ T
8SC%O\,
"aq'R(/`c
private String sSiteURL; //Site's URL p&N#_dmlH
private String sFilePath; //Saved File's Path oyx^a9
private String sFileName; //Saved File's Name E m{aM
private int nSplitter; //Count of Splited Downloading File XOy2lJ/
}Ln@R~[
~/-eyxLTm
public SiteInfoBean() -rSIBc:$8
{//nSplitter的缺省值为5 {fDTSr?/
//default value of nSplitter is 5 vF4]ux&
this("","","",5); |L::bx(
} kV&9`c+
aeP[+I9
cpZc9;@IC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S%mfs!E>
{ Ug%_@t/?
sSiteURL= sURL; jQh^WmN
sFilePath = sPath; 5[gh|I;D
sFileName = sName; !EBY@ Y1
this.nSplitter = nSpiltter; 0Scm?l3
\9{F5Sz
6GL=)0Ah
} e3[:D5
T~xwo
3 hKBc0
public String getSSiteURL() }< 5F
{ C~4PE>YtTv
return sSiteURL; %.HJK
} zsXpA0~3s
..W-76{
s9)8b$t]
public void setSSiteURL(String value) LM)`CELsYc
{ aM=D84@
sSiteURL = value; ?GT@puJS-
} @T-p2#&
`>lzlEhKV
,0N94pKy
public String getSFilePath() .12aUXo(
{ </"4 zD|
return sFilePath; $_;e>*+x
} 1wj:aD?g
If-_?wZe
T7*wS#z)h
public void setSFilePath(String value) &^".2)zU
{ 0?DC00O
sFilePath = value; 8wZf]_
} 3ec`Wa
39i9wrP
SA"p\}"
public String getSFileName() s +s" MI
{ P9Q~r<7n
return sFileName; !CTxVLl"F
} Cby;?F6w
B%s7bS
U7@AC}.+
public void setSFileName(String value) vGy8Qu>
{ i[jJafAcN
sFileName = value; XXZaKgsq
} / |r'
_fk#<
O[^%{'
public int getNSplitter() oqd;6[%G
{ _qwQ;!9
return nSplitter; ;,h/
} Kv&g5&N,
YIRZ+H<Q
(N-RIk73/O
public void setNSplitter(int nCount) =uHnRY
{ }yn0IWVa
nSplitter = nCount; kRJ4-n^@><
} 21X`h3+=
} Dim> 7Wbh
"r4AY
N2r/ho}8
/* uN*KHE+h
**Utility.java ;bzX%f?|G
*/ Ex amD">T
package NetFox; Uu s.
;*TIM%6#
S[3iA~)Z-
public class Utility { XN=67f$Hw
,_.I\EY[
}Db[ 4
public Utility() enS}A*Io
{ s8"8y`u
{P%9
u7%D6W~m0
} IY'=DePd
zG }?
//线程睡眠 f"G-
public static void sleep(int nSecond) CvSIV7zYo
{ 8`>h}Q$
try{ 5zJj]A
Thread.sleep(nSecond); ^FmU_Q0
} >eQr<-8
catch(Exception e) 7"F*u :
{ #AkV/1Y
e.printStackTrace (); h0--B]f@
} !l?.5Pm])
} $4kH3+WJ
8I20*#
//日志 1/1Xk,E
public static void log(String sMsg) 'VyM{:8
{ Bs+(L [Z
System.err.println(sMsg); ok^d@zI
} =uk0@hy9b
NL=|z=q
C (n+SY^
public static void log(int sMsg) Mv544>:
{ EC2+`HJ"
System.err.println(sMsg); EKEjv|_)
} $EZN1\
} _ nA p6i
$n^MD_1!
@bM2{Rh:
/* &X@Bs-
**TestMethod.java l&4,v
*/ <U5wB]]
package NetFox; uzmk6G v
4'j sDcs
F^"_TV0va
public class TestMethod { `e9$,h|4
Q?ahr~qo
M#"524Nz
public TestMethod() 4a0:2 kIKa
{ ///xx/weblogic60b2_win.exe [${ QzO
try{ MObt,[^W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Nk=JBIsKv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X'.qYsS
SiteFileFetch fileFetch = new SiteFileFetch(bean); @2pu^k^
fileFetch.start(); C*U'~qRK
} ;k"Bse!/
catch(Exception e){e.printStackTrace ();} iLP7!j
9CA^B2u
f.aSKQD
} q{s(.Uq$&
0q>P~]Ow
i|w8.}0
public static void main(String[] args) Wcb7 ;~K
{ j?y LDLj
new TestMethod(); 5>3}_
} d(vsE%/!
} EXP%Mk/
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