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)); G\kpUdj}
} TH:W#Ot
for(int i=0;i<nEndPos.length-1;i++) 50$W0L$
{ ~*-qX$gr
nEndPos = nStartPos[i+1]; $FX,zC<=
} R\O.e
nEndPos[nEndPos.length-1] = nFileLength; vFhz!P~
} ?\y%]1
} g)1X&>
h/m6)m.D
WU)Ss`s \
//启动子线程 Zh'&-c_J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,b|-rU\
for(int i=0;i<nStartPos.length;i++) L;/n!k.A
{ x?sI;kUw8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J=H)JH3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eB]R3j{
nStartPos,nEndPos,i); 7lA:)a_!]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sn{tra
fileSplitterFetch.start(); y{=>$C[
} Dl,`\b@Fw3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K{=PQ XSU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (kw5>c7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OZ(dpV9.S
nEndPos = " + nFileLength); T?wzwGp-[
// fileSplitterFetch[nPos.length-1].start(); tSHFm-q`
{' 5qv@3
g0&\l}&%U
//等待子线程结束 =.Tv)/ea
//int count = 0; $>q@SJ1q
//是否结束while循环 c0rk<V%5+
boolean breakWhile = false; vhgLcrn
n}nEcXb
jndGiMA
while(!bStop) Q8nId<\(
{ ,o#kRWRG
write_nPos(); bGmx7qt#
Utility.sleep(500); *hY2.t; X
breakWhile = true; wkb$^mU
AkBMwV
\RG!@$i
for(int i=0;i<nStartPos.length;i++) diT=x52
{ (<c7<_-H
if(!fileSplitterFetch.bDownOver) T.:+3:8|F
{ $l[Rh1z`;+
breakWhile = false; V9%aBkf8w
break; A;X=bj _&a
} ['qnn|
} L"+$Wc[|
if(breakWhile) }j{!-&
break; t#E}NR
2-+f1,
% ZU/x d
//count++; 6sfwlT
//if(count>4) hVpCB,
// siteStop(); n~IVNB*
} pW\'ZRj
[5d2D,)
15\Ph[6g
System.err.println("文件下载结束！"); kSncZ0K{
} \%jVg\4'
catch(Exception e){e.printStackTrace ();} 2\D8.nQr
} #\rwLpC1u
J;Rv ~<7
\E1U@6a
//获得文件长度 J4$! 68
public long getFileSize() q>!L6h5]t
{ CB\{!
int nFileLength = -1; >p\e0n
try{ wucV_p.E
URL url = new URL(siteInfoBean.getSSiteURL()); [tT8_}v$LN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ka!I`Yf
httpConnection.setRequestProperty("User-Agent","NetFox"); T.e.{yO
X@N$Z{
+|cI:|H>
int responseCode=httpConnection.getResponseCode(); JtKp(k&
if(responseCode>=400) #Il_J\#
{ SuBeNA[&
processErrorCode(responseCode); ;r\(p|e
return -2; //-2 represent access is error E\7m<'R
} d[gl]tj9
$"JpFT
}CL"S_>1
String sHeader; cV K7
[4Ll0GSp
|iYg >
for(int i=1;;i++) RSfM]w}Hq#
{ .\Fss(Zn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rt7<Q47QE
//Utility.log(in.readLine()); o?Nu:&yE
sHeader=httpConnection.getHeaderFieldKey(i); lU]un&[N
if(sHeader!=null) vE, 37
{ c~,23wP1
if(sHeader.equals("Content-Length")) CBT>"sYE1
{ Lm*VN~2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); is;XmF*5=
break; WKM)*@#,
} .9G<y 4
} \YJy#2K
else l;X|=eu'
break; u0)7i.!M
} FyL_xu\e
} H[Q_hY[>V
catch(IOException e){e.printStackTrace ();} ws/63d*
catch(Exception e){e.printStackTrace ();} ^)yTBn,
N^0uit
CG]Sj*SA~
Utility.log(nFileLength); XkmQBV"
"VxWj}+]
E4.SF|=x
return nFileLength; Oc?+M 5
} uYG^Pc^v
&O\(;mFc
4pU>x$3$
//保存下载信息（文件指针位置） )u ?' ;
private void write_nPos() ?NNn:tiD
{ AN:@fZ
try{ .S\&L-{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7cg*|E@
output.writeInt(nStartPos.length); qf)$$qi
for(int i=0;i<nStartPos.length;i++) >XW*T5aUA
{ )x,8D ~p'
// output.writeLong(nPos); N6QVt f.
output.writeLong(fileSplitterFetch.nStartPos); 4b]a&_-}
output.writeLong(fileSplitterFetch.nEndPos); F9q8SA#"
} gieJ}Bv
output.close(); M&Y .;
} 0"k|H&
catch(IOException e){e.printStackTrace ();} [t]X/O3<
catch(Exception e){e.printStackTrace ();} X*oMFQgP
} (LAXM x
6X g]/FD
+0z 7KO%^^
//读取保存的下载信息（文件指针位置） u8zbYd3
private void read_nPos() w*j$uW6{
{ IputF<p
try{ wgeNs9L
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >:sUL<p
int nCount = input.readInt(); t6N*6ld2b
nStartPos = new long[nCount]; s'P( ,!f
nEndPos = new long[nCount]; }peBR80tQ
for(int i=0;i<nStartPos.length;i++) n7LfQWc
{ `xS{0P{uj
nStartPos = input.readLong(); /BKe+]dS*
nEndPos = input.readLong(); fg%&N2/(.B
} `rY2up#%
input.close(); wz8PtfZ
} z;u> Yz+3
catch(IOException e){e.printStackTrace ();} DdV'c@rq+
catch(Exception e){e.printStackTrace ();} o(A|)c4k
} ~o3Hdd_#}N
$e%2t^ i.g
Tq<2`*Qs
private void processErrorCode(int nErrorCode) JEn3`B!*
{ qf'm=efRyu
System.err.println("Error Code : " + nErrorCode); {WN(&eax
} pz^<\
.o{0+fC#
ytEC
//停止文件下载 rk2xKm^w
public void siteStop() dP$GThGl
{ oj.A,Fh
bStop = true; z:Sigo_z[
for(int i=0;i<nStartPos.length;i++) {aKqXL[UP
fileSplitterFetch.splitterStop(); -php6$|
=?0lA_ 0
<c[U#KrvJ
} !X>=l
} #1'\.v
//负责部分文件的抓取 ~Z/ ^c,[:
**FileSplitterFetch.java q=HHNjj8
*/ vEM(bT=H
package NetFox; /{2*WI;
:!&;p
z"4]5&3A
import java.io.*; +KGZHO!
import java.net.*; VvbFp
_GQz!YA
gxPx&Z6jF
public class FileSplitterFetch extends Thread { TjK{9A
Gnm4gF!BI
BDY}*cX
String sURL; //File URL 31+;]W=
long nStartPos; //File Snippet Start Position v;#=e$%}MO
long nEndPos; //File Snippet End Position ~Aad9yyi
int nThreadID; //Thread's ID W_O)~u8
boolean bDownOver = false; //Downing is over m%+IPZ2m
boolean bStop = false; //Stop identical ~\nBjM2
FileAccessI fileAccessI = null; //File Access interface u D 5%E7
4Q=ftY<
8?t"C_>*e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pqM~l&
{ 3b'tx!tFN
this.sURL = sURL; ? ]sM8Bd}
this.nStartPos = nStart; HJ?+A-n/
this.nEndPos = nEnd; +YOKA*
nThreadID = id; ~cAZB9Fa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q"KnLA(
} +,+vkpL-%
;P&y,:<m:
2s*#u<I
public void run() }y%`)lz~;
{ (%CZ*L[9Z
while(nStartPos < nEndPos && !bStop) z@s5m}
{ 1:C:?ZC#c
8GPIZh'0h
~jU/<~s
try{ 80}+MWdo
URL url = new URL(sURL); &ej8mq"\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [@<sFP;g
httpConnection.setRequestProperty("User-Agent","NetFox"); 2 gq$C"
String sProperty = "bytes="+nStartPos+"-"; ivO/;)=t
httpConnection.setRequestProperty("RANGE",sProperty); |s7`F%
Utility.log(sProperty); PW(\4Q\
;?fS(Vz~
<mA'X V,
InputStream input = httpConnection.getInputStream(); =-cwXo{Q.O
//logResponseHead(httpConnection); !9*c8bL D
3gWvmep1
#mR4fst
byte[] b = new byte[1024]; P`4]-5gE
int nRead; <%}QDO8\i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .D,p@4
{ mM.*b@d-
nStartPos += fileAccessI.write(b,0,nRead); `cz2DR-"
//if(nThreadID == 1) 'z@0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5FVndMM#y
} Tl]e%A`|
nL@KX>
zIC;7 5#
Utility.log("Thread " + nThreadID + " is over!"); ;DA8B'^>
bDownOver = true; p;)"
//nPos = fileAccessI.write (b,0,nRead); j| Wv7
} K`&oC8p
catch(Exception e){e.printStackTrace ();} 75nNh~?)\
} )C(>H93
} :Eh\NOc_O
*,C(\!b !?
q>f<u&
//打印回应的头信息 r0t^g9K0
public void logResponseHead(HttpURLConnection con) H~eRT1
{ -&82$mj
for(int i=1;;i++) )M=ioE8`h
{ Dih6mTP{
String header=con.getHeaderFieldKey(i); j.~!dh$mg
if(header!=null) WH ?}~u9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `.x$7!zLC
Utility.log(header+" : "+con.getHeaderField(header)); !f>d_RG
else AIb2k
break; OJT1d-5p
} 4p%A8%/q
} 6-`|:[Q~
bQe^Px5 !.
U<XSj#&8|
public void splitterStop() Qjx?ri//
{ A[G0 .>Wk
bStop = true; yJuQ8+vgR}
} %6Q4yk
T|&[7%F3"
bNT9 H`P
} tg^sCxz9]
gOgps:
\txbhWN
/* yx V:!gl
**FileAccess.java 2|\A7.
*//文件访问(定位，写) d0'JC*
package NetFox; Z*G(5SqUh"
import java.io.*; fEB7j-t
Cg*H.f%Mr
}@if6(0
public class FileAccessI implements Serializable{ $R<Me
zy*/T>{#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9&<x17'
RandomAccessFile oSavedFile; \OlmF<~
long nPos; 5s(1[(
@aJ!PV'ms
]v+31vdf:O
public FileAccessI() throws IOException \uss Uv
{ S/;bU:
this("",0); @p\}pY$T
} O-)-YVU
Vh>Z,()>>@
s/089jlc
public FileAccessI(String sName,long nPos) throws IOException 26CS6(sn
{ G[jW<'f
oSavedFile = new RandomAccessFile(sName,"rw"); \"hJCP?,
this.nPos = nPos; e<r,&U$
oSavedFile.seek(nPos); e%W$*f
} U`hY{E;
YKQr, Now
\d::l{VB
public synchronized int write(byte[] b,int nStart,int nLen) EJ2yO@5O
{ )>BHL3@
int n = -1; XrZ*1V
try{ ;;&}5jcV
oSavedFile.write(b,nStart,nLen); n_'{^6*O
n = nLen; cu+FM
} I!^O)4QRx
catch(IOException e) p,"g+ MwP
{ qWb+r
e.printStackTrace (); l&?ii68/
} w6j/ Dq!
Dd`Mv$*d8
7g3>jh
return n; {z|;Xi::"
} 0wS+++n$5
<tioJG{OT
z;y:9l
} |fo0
@V!r"Bkg.
5 (A5Y-B
/* ZRYEqSm
**SiteInfoBean.java }\C-} Q
*/ 9?k_y ZV
package NetFox; Vx-7\NB
t45Z@hmcW
yq$,,#XDD=
public class SiteInfoBean { aM;W$1h
`jOX6_z?I
TiH)5
private String sSiteURL; //Site's URL 4ni3kmvX
private String sFilePath; //Saved File's Path 0x!2ihf
private String sFileName; //Saved File's Name G%Lt.?m[
private int nSplitter; //Count of Splited Downloading File t]e;;q=L.
[pM V?a[
[ Fz`D/
public SiteInfoBean() n?c]M
{//nSplitter的缺省值为5 & GreN
//default value of nSplitter is 5 iJ~Vl"|m
this("","","",5); ()H:UvM=t
} *2GEnAZb7n
{*ob_oc
y.q(vzg\_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QeK*j/
{ *Aa?yg:=
sSiteURL= sURL; x)_0OR2lkp
sFilePath = sPath; =J~ x
sFileName = sName; [0D Et
this.nSplitter = nSpiltter; 3@]SKfoo1
;{[.Zu
<Z/x,-^*<
} p"U,G -_
i _%Q`i
RG4sQ0
public String getSSiteURL() R`~z0d.
{ +="e]Yh;
return sSiteURL; a.zpp'cEb
} ,#kIr
WH\))y-
9U%N@Dq`Z
public void setSSiteURL(String value) zO MA
{ |*0<M(YXN
sSiteURL = value; Dmu/RD5X:
} XSZ k%_
}_68j8`
ih;]nJ]+-
public String getSFilePath() 9\DQ>V TQ
{ fP `b>]N_
return sFilePath; I'0@viF"Nx
} aX}P|l
Mwr"~?\\
82DmG@"s2
public void setSFilePath(String value) ;/rXQe1
{ !dC<4qZ\C
sFilePath = value; |1>*;\o-
} x HhN
{b
=Fr(9(
public String getSFileName() ])!o5`ltZ
{ 5x>}O3Q_
return sFileName; !!? Mw
} HZf/CE9T
y)@[Sl>
W0]gLw9*
public void setSFileName(String value) ZXuv CI
{ XUlS\CH@{
sFileName = value; &mtJRfnu
} WV_.Tiy<
qCnZhJ
LMAE)]N
public int getNSplitter() !GNBDRr
{ hs$GN]
return nSplitter; M%kO7>h8
} ssN6M./6
w_{wBL[3e
[6XF=L,!
public void setNSplitter(int nCount) &?yZv{
{ I\$X/t +dH
nSplitter = nCount; AGYc |;
} pv Gf\pu
} D5*q7A6
ZGKu>yM
:dQ B R
/* /Y7<5!cS
**Utility.java OD6\Mr2=
*/ ub\MlSr
package NetFox; 6U R2IxbE
5Ezw ~hn
=t H:,SH
public class Utility { zIu E9l
< F.hZGss7
N%*5T[.
public Utility() e(GP^oK
{ sWc*5Rt
"Pu!dJ5[]
Xy$3VU*
} m0;CH/D0
K+3IWZ&+dG
//线程睡眠 }n3/vlW9
public static void sleep(int nSecond) zU gE~
{ EkjN{$*
try{ xQ^E"Q,1
Thread.sleep(nSecond); 1Y7Eajt-5
} ECrex>zr%
catch(Exception e) Vt".%d/`7
{ 3 I@}my1
e.printStackTrace (); ]dGw2y
} \%f q
} 06c>$1-?
3W3ZjdV+
//日志 Af'" 6BS
public static void log(String sMsg) 7|$:=4
{ GS a[ oh
System.err.println(sMsg); ujR_"r|l
} XkXHGDEf1
B"TAjB& *
ZaV8qAsP
public static void log(int sMsg) UBaAx21x
{ MHX?@. v
System.err.println(sMsg); ->g*</
} ZjQ |Wx
} JGsx_V1t
2.l Z:VLN
O4cr*MCb5
/* jv%kOovj
**TestMethod.java {=!b/l;@
*/ t>urc
package NetFox; ] 2eK
u'|4?"uz
lOuHVa*}
public class TestMethod { XWS%zLaK
zQ@I}K t
{|&5_][
public TestMethod() toya fHf
{ ///xx/weblogic60b2_win.exe AX;8^6.F3
try{ }Qip&IN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &,c``z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z(_Ss@ $
SiteFileFetch fileFetch = new SiteFileFetch(bean); P@$/P99
fileFetch.start(); 8S mCpg
} K?B{rE Lp
catch(Exception e){e.printStackTrace ();} !`g~F\l
@SJL\{_
)}D'<^=#T
} P9^-6;'Y
uxtWybv
ein4^o<f.
public static void main(String[] args) Hv sob
{ b J=Jg~&
new TestMethod(); `k[-M2[
} v 1z
} !sDh4jQ`
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