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)); puG$\D-[
} *^bqpW2$q
for(int i=0;i<nEndPos.length-1;i++) R;.zS^LL
{ sEt5!&
nEndPos = nStartPos[i+1]; y>'^<xk
} @OZW1p
nEndPos[nEndPos.length-1] = nFileLength; cR[)[9}
} W#$ pt>h)
} -\b~R7VQ
YT+fOndjaF
)7<JGzBZ1
//启动子线程 tbJB0T|G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w}zl=w{G
for(int i=0;i<nStartPos.length;i++) KV k 36;$
{ ld-c?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5u'"m<4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^Jcs0c @\
nStartPos,nEndPos,i); y&-wb'==p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lsCD%P
fileSplitterFetch.start(); S)Sv4Qm
} H[U$4 %t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !lG5BOJM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G#ZU^%$M,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H2 5Mx>|d
nEndPos = " + nFileLength); ZMids"Xdf
// fileSplitterFetch[nPos.length-1].start(); DPw"UY:
w6+X{
1"RO)&
//等待子线程结束 &~:b&
//int count = 0; EjV,&7o)
//是否结束while循环 iIA5ylf{E
boolean breakWhile = false; dms R>Q
..UmbJJ.u
fLA!oeq{&}
while(!bStop) sn '#]yM
{ j#$ R.
write_nPos(); Q@6OIE
Utility.sleep(500); G4{ zt3{
breakWhile = true; PCF!Y(l
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*>h"}e41
for(int i=0;i<nStartPos.length;i++) p 2It/O
{ x[U/ 8#f&
if(!fileSplitterFetch.bDownOver) "X4OUk
{ c}kZx1
breakWhile = false; A1Ia9@=Mf
break; S75wtz)e
} hn{]Q@(I
} >0~|iRySi
if(breakWhile) r&@#,g
break; 75v 5/5zRn
1q0DOf]!T
RJYuyB
//count++; fdc ?`4
//if(count>4) 'e^,#L_!o
// siteStop(); y/k6gl[`
} IeLG/ fB
R$X1Q/#md
Q#Q]xJH
System.err.println("文件下载结束！"); N`1:U 4}
} 2>p K
catch(Exception e){e.printStackTrace ();} 58\Rl
} bq/m?;
{P"$;_Y"<
D+lzISp~e
//获得文件长度 +ObP[F
public long getFileSize() >&6pBtC_
{ [tGAo/
int nFileLength = -1; D^yZ!}Kl
try{ -'BC*fVr
URL url = new URL(siteInfoBean.getSSiteURL()); 0ubT/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _W'>?e0i
httpConnection.setRequestProperty("User-Agent","NetFox"); CMB:%
`% k9@k.
6*8"?S'
int responseCode=httpConnection.getResponseCode(); J@PwN^`
if(responseCode>=400) ~CIA6&
{ ) (unL`y
processErrorCode(responseCode); fDt#<f 4;
return -2; //-2 represent access is error 6My=GByC
} xy)Y)yp
u&yAMWl
qgg/_H:;w
String sHeader; nd*9vxM
23?\jw3w
Wjc1EW!2x
for(int i=1;;i++) bRT1~)
{ Cj"+` C)l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^ cpQ*Fz
//Utility.log(in.readLine()); >a7OE=K
sHeader=httpConnection.getHeaderFieldKey(i); 8dgI&t
if(sHeader!=null) /?uA{/8
{ JJ`RF
if(sHeader.equals("Content-Length")) I4{uw ge
{ yqR2^wZ%r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c]LE9<G
break; <wWZ]P2]
} qp3J/(F
} nt.A X
else &?UIe]
break; -x)Oo`
} 2Z K:S+c
} Y5?*=eM
catch(IOException e){e.printStackTrace ();} *"Yz"PK
catch(Exception e){e.printStackTrace ();} ,rj_P
Qz)1wf'y
xj`ni G
Utility.log(nFileLength); .|W0B+Z8
&x6Z=|Ers
E0; }e
return nFileLength; Br^4N9
} tS#=I.ET
&XAG| #
nAIV]9RAZ%
//保存下载信息（文件指针位置） 29{Ep
private void write_nPos() 0,$eiY)u$
{ ~2u~}v5m7
try{ 1AMxZ (e
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9RA~#S|(T
output.writeInt(nStartPos.length); ~,[-pZ<
for(int i=0;i<nStartPos.length;i++) :U;n?Zu S
{ Y~z3fd
// output.writeLong(nPos); Ua0fs|t1v
output.writeLong(fileSplitterFetch.nStartPos); '-C%?*ku
output.writeLong(fileSplitterFetch.nEndPos); vF yl,S5A
} +e VWTRG
output.close(); _~~:@fy
} wJ#fmQXKJ5
catch(IOException e){e.printStackTrace ();} WqQAt{W/<
catch(Exception e){e.printStackTrace ();} &j=FxF9o
} n7-|\p!xP6
z H$^.1
)H=}bqn
//读取保存的下载信息（文件指针位置） 8T"C]
private void read_nPos() yF2|w=!
{ tg =ClZ-
try{ Y'K+O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t8SvU
int nCount = input.readInt(); ]^aOYtKX
nStartPos = new long[nCount]; /zxLnT; 5
nEndPos = new long[nCount]; dJyf.VJ
for(int i=0;i<nStartPos.length;i++) X*f#S:kiNU
{ C>l{_J)n
nStartPos = input.readLong(); Su"9`
nEndPos = input.readLong(); T%0vifoQ_$
} o[Ojl.r<
input.close(); I ACpUB
} V9aGo#
catch(IOException e){e.printStackTrace ();} iA*^`NMaT
catch(Exception e){e.printStackTrace ();} ^na8d's:
} ]?KTw8j}
MR4e.+#E
}/)vOUcEd
private void processErrorCode(int nErrorCode) ^3~+|A98M
{ 2J7= O^$?
System.err.println("Error Code : " + nErrorCode); bm/pLC6%.
} cyYsz'i m
XS:W{tL!
X}"Ic@8
//停止文件下载 D*7JE
public void siteStop() Y)~Y;;/G
{ tYb8a
bStop = true; >4I,9TO
for(int i=0;i<nStartPos.length;i++) Gg'sgn
fileSplitterFetch.splitterStop(); JH3$G,:zM
+=.>9
hG1\
} %{M_\Ae#
} IQz"FH?
//负责部分文件的抓取 {jyI7r#X
**FileSplitterFetch.java {WokH;a/
*/ kH;DAphk
package NetFox; =[A5qwyv
ai,\'%N
&8=wkG%
import java.io.*; JSXJlau
import java.net.*; %@C(H%obWd
V2Iqk]V%y
FKYPkFB
public class FileSplitterFetch extends Thread { <jt_<p +
u.\FNa
#kGgzO
String sURL; //File URL U`)\|\NY
long nStartPos; //File Snippet Start Position C:r@)Mhq
long nEndPos; //File Snippet End Position ?+3vK=Rf}
int nThreadID; //Thread's ID +#* F"k(
boolean bDownOver = false; //Downing is over .\Z/j
boolean bStop = false; //Stop identical kHWW\?O
FileAccessI fileAccessI = null; //File Access interface 2EO WbN}M
R7'6#2y
x}^:Bs+j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IBP3
{ mGZJ$|
this.sURL = sURL; g=ehAg
this.nStartPos = nStart; u92);1R
this.nEndPos = nEnd; <@F.qMl
nThreadID = id; bQ%6z}r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ig-V^P
} `(- nSQ
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;`")3~M3*
public void run() )GT*HJR(vc
{ g3V bP
while(nStartPos < nEndPos && !bStop) .Iu8bN(L`
{ ~mSW.jy}=-
R #f*QXv
n'?AZ4&z
try{ 9N+3S2sBx&
URL url = new URL(sURL); =D>,s)}o3;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H[WsHq;T+9
httpConnection.setRequestProperty("User-Agent","NetFox"); Uzi.CYVs%
String sProperty = "bytes="+nStartPos+"-"; ol[sX=5 *
httpConnection.setRequestProperty("RANGE",sProperty); |2L|Zp&
Utility.log(sProperty); o"kVA;5<G
96(3ilAt
g36:OK"
InputStream input = httpConnection.getInputStream(); cVV@MC
//logResponseHead(httpConnection); %#_"Ie
Pv#Oea?
(&Kv]--
byte[] b = new byte[1024]; m{v*\e7P
int nRead; @V\u<n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R^p'gQc$
{ \X*Es.;|x
nStartPos += fileAccessI.write(b,0,nRead); |>Ld'\i8
//if(nThreadID == 1) ^y,Ex;6o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Za110oF
} ~M c'~:{O
]NEr]sc-"F
S^8C\ E
Utility.log("Thread " + nThreadID + " is over!"); VYR<x QA
bDownOver = true; L2sUh+'|
//nPos = fileAccessI.write (b,0,nRead); o^efeI
} gTM*td(~^
catch(Exception e){e.printStackTrace ();} $q|-9B
} 7^oO N+=d
} |#b]e|aP
Yy 8?X9r.
n%S%a>IQj
//打印回应的头信息 >fq]c
public void logResponseHead(HttpURLConnection con) sQ}E4Iq1#S
{ ;_K3/:
for(int i=1;;i++) G(3wI}
{ )K}-z+$)k
String header=con.getHeaderFieldKey(i); mfW}^mu
if(header!=null) q+Ec|Xd e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L*8U.{NY
Utility.log(header+" : "+con.getHeaderField(header)); _'*Vcu`Y
else t?aOZps
break; s+-V^{Ht
} {i^F4A@=Z
} {V^|9j:\K
G`e!WvC
R<<U(.E
public void splitterStop() e0$.|+
{ cr`NHl/XF
bStop = true; p9y@5z
} Bjp4:;Bb
`DFo:w!k
A"}Ib'
} &}rmDx
Z}AhDIw!G
;Tec)Fl
/* e~ZxDAd
**FileAccess.java t?(fDWd|-
*//文件访问(定位，写) W; zzc1v
package NetFox; ?u4t;
import java.io.*; 'lMDlTU O
P!yOA_)as
m S4N%Q
public class FileAccessI implements Serializable{ /8? u2 q
h J H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LTTMxiq[*
RandomAccessFile oSavedFile; M{jJ>S{g
long nPos; 4M)oA|1w
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q&kG>
public FileAccessI() throws IOException zN&m-nrw
{ X@Bg_9\i
this("",0); m7|S'{+!
} +Ym#!"
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|%g)H,6c
public FileAccessI(String sName,long nPos) throws IOException ]p@q.P
{ )B9/P>c
oSavedFile = new RandomAccessFile(sName,"rw"); ^ AJ_
this.nPos = nPos; +7mUX
oSavedFile.seek(nPos); ELZ@0,
} @x@wo9<Fc
UZ;FrQ(l{
=lmelo#m&
public synchronized int write(byte[] b,int nStart,int nLen) GD1L6kVd1
{ 2[CHiB*>
int n = -1; rM`z2*7%d
try{ H-qbgd6&>R
oSavedFile.write(b,nStart,nLen); jfU$qo!gi
n = nLen; 717OzrF}A?
} }1mkX\wWP
catch(IOException e) .^wBv 'Y
{ = G>Y9Sc
e.printStackTrace (); +,zV [\
} tRbZX{
2t;3_C
qV)hCc/ ~
return n; i.0d>G><@
} `Ip``I#A
20w4 '@sq
zmhAeblA
} w$0*5n>)
re fAgS!=q
6t{G{ ]
/* 4xF}rm
**SiteInfoBean.java cp&1yB
*/ s_P[lbHt.
package NetFox; *>k6n5%
KP_7h/e
zHD8\*
public class SiteInfoBean { u`"Y!*[ -
qGi\*sc>x
d~KTUgH'<
private String sSiteURL; //Site's URL GA"vJFQ
private String sFilePath; //Saved File's Path 0v|qP
private String sFileName; //Saved File's Name `-g$ 0lm7
private int nSplitter; //Count of Splited Downloading File XPLm`Q|1#t
qu0q LM
^ f[^.k$3d
public SiteInfoBean() y/>Nx7C0=2
{//nSplitter的缺省值为5 BKK@_B"
//default value of nSplitter is 5 mGoNT
this("","","",5); 63'L58O
} 5R6QZVc
7#j9"*
,U~in)\ U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %edTW[C`
{ P! P` MX
sSiteURL= sURL; DAy|'%rF1-
sFilePath = sPath; Y=@iD\u
sFileName = sName; *i"Mu00b
this.nSplitter = nSpiltter; p\}!uS4 (
l-2lb&n
#!>`$
} 0x# V
{KSy I#
1ZXRH;J40
public String getSSiteURL() PHMp,z8
{ | Pqs)Mb]
return sSiteURL; ypNeTR$4
} ; hU9_e
CoV@{Pi
.uB[zJc
public void setSSiteURL(String value) C't%e
{ 6n/KL
sSiteURL = value; ;x&3tN/I
} Hp@cBj_@P2
*fSX3Dk
X{iidTW`xv
public String getSFilePath() @ev^e!B
{ *-'`Ea
return sFilePath; oJZ0{^
} 0ke1KKy/d
O]l-4X#8F
qnzNJ_ `R
public void setSFilePath(String value) Q'[~$~&`
{ ?sxf_0*
sFilePath = value; w$`u_P|@E:
} I.o3Old
(kx>\FIK*
HS|x
public String getSFileName() fN 1:'d
{ qJ$S3B
return sFileName; R(2MI}T
} BT(G9Pj;
w_YY~Af
yCv"(fNQ
public void setSFileName(String value) zu1gP/
{ V{{UsEVO
sFileName = value; II.Wa&w}
} M+4S>Sjw
th=45y"C
?hW(5]p|
public int getNSplitter() `U;V-
{ ^fM=|.?
return nSplitter; d_98%U+u
} N]|U-fN\
=OR&,xt
5a* Awv}
public void setNSplitter(int nCount) ,-> P+m5
{ ND5E`Va5R
nSplitter = nCount; *JaFt@ x
} C,u;l~zz
} #elaz8 5
\)PS&Y8n
U4Pk^[,p1G
/* $P&27
**Utility.java U9AtC.IG!
*/ CjA}-ee
package NetFox; w2tkJcQ3
.sUL5`
vaZ?>94
public class Utility { BimM)4g
a[gN+DX%L
r3.v^
public Utility() qxD<mZ@-R0
{ wSs78c=
;<`
zyI4E\
} x[%% )[d
;}k_2mr~
//线程睡眠 {XYf"ONi
public static void sleep(int nSecond) $Vm J[EF1
{ 3K_!:[
try{ J~G"D-l<9/
Thread.sleep(nSecond); QLTE`t5w3'
} i)e)FhEY6
catch(Exception e) SiJX5ydz
{ q}5&B=2pM
e.printStackTrace (); upH%-)%'
} /XW,H0pR
} 2qkC{klC^M
4U:+iumy2
//日志 >l5JwwG
public static void log(String sMsg) z~a]dMs"(P
{ mH3{<^Z6
System.err.println(sMsg); >JhIRf
} d>7bwG+k
g:c @
fmq^AnKd
public static void log(int sMsg) FkT% -I
{ jfrUOl'l
System.err.println(sMsg); 'w7{8^Z2
} {EupB?
} B6vmBmN
';7|H|,F
8 _[f#s`)
/* Qod2m$>wp}
**TestMethod.java c[0$8F>
*/ z'X_s.9F
package NetFox; :ui1]its4
]# T9v06w
WJL,L[XC
public class TestMethod { P.1iuZ "w
]j:Ikb}
ByZ.!~
public TestMethod() 63- YWhs;
{ ///xx/weblogic60b2_win.exe Bj7\{x,?
try{ z*>CP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )u&_}6z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9~mi[l~
SiteFileFetch fileFetch = new SiteFileFetch(bean); `0Q:d'
fileFetch.start(); ;7<a0HZ5!
} j|(bDa4\
catch(Exception e){e.printStackTrace ();} z:R2Wksg
4%j&]PASa1
|qNrj~n@
} LGCL*Qbsg
_?_Svx2
<FK7Rz:4T
public static void main(String[] args) 0+:.9*g=k
{ @]#+`pZ4A
new TestMethod(); x{*!"a>
} S8vmXlD
} C127he
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