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)); WS1Y maV
} 5twG2p8
for(int i=0;i<nEndPos.length-1;i++) UD5hk
{ g(S4i%\
nEndPos = nStartPos[i+1]; Q%V530 P;
} N~(?g7
nEndPos[nEndPos.length-1] = nFileLength; $UdFm8&
} =;?Maexp3$
} UVsF !0
4]%MrSjS
0Yr-Q;O<f
//启动子线程 Rp}Sm,w(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T\7t#Z k
for(int i=0;i<nStartPos.length;i++) xp\6,Jyh
{ 1nE`Wmo.2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z[\nyj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K#yCZ2
nStartPos,nEndPos,i); S3c%</'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i[vOpg]J
fileSplitterFetch.start(); 8ROZ]Xh,x
} 'puiahA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sB'~=1m^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -8t&&fIA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", - KaU@t
nEndPos = " + nFileLength); ovvg"/>L
// fileSplitterFetch[nPos.length-1].start(); 4L&Rs;
#[~f6s9D
zZPXI&,
//等待子线程结束 V%FWZn^
//int count = 0; Qf}}/k|)k
//是否结束while循环 w?R#ly
boolean breakWhile = false; nYnv.5
v-B&"XGy:
X`k#/~+0
while(!bStop) $~1~+s0$
{ /nNrvMtv
write_nPos(); .;;:t0PB
Utility.sleep(500); cN]g^
breakWhile = true; NH8\&#}nAK
'77Gg
"J%dI9tM{
for(int i=0;i<nStartPos.length;i++) aByd,uSe)_
{ ]_:j+6i
if(!fileSplitterFetch.bDownOver) " VSma
{ qW9~S0sl
breakWhile = false; XchVsA
break; OZ Hfd7K4A
} dpB\=
} 5uL!Ae
if(breakWhile) RjGJfN{
break; p4wx&VLi
Z!oq2,ia
x:`"tJa
//count++; %xP'*EaM?
//if(count>4) h`V#)Q
// siteStop(); Hni?r!8r
} |j!U/n.%w
HD8*>p.
kD_616
System.err.println("文件下载结束！"); RH0J#6C/
} 2NZC,znQ
catch(Exception e){e.printStackTrace ();} ITBa ^P
} {&0u:
_tR?WmNH=
*`~]XM@H
//获得文件长度 2OsS+6,[x
public long getFileSize() 5LJ0V
{ qcGsx2
int nFileLength = -1; -DL"Yw}
try{ dd:vQOF;
URL url = new URL(siteInfoBean.getSSiteURL()); ZXC_kmBN/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }}gtz-w
httpConnection.setRequestProperty("User-Agent","NetFox"); 4{CeV7
^~JF7u
S$NJmXhx5
int responseCode=httpConnection.getResponseCode(); {YF(6wVl
if(responseCode>=400) J*;= f8
{ OZ6:u^OS]
processErrorCode(responseCode); xt1Ug~5
return -2; //-2 represent access is error .njk^,N
} 8M8Odz\3 q
%abc-q
<N,:w`g#
String sHeader; hkl9EVO)
/|>?!;
G|.6%-
for(int i=1;;i++) !v<`^`x9I
{ - `{T?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }j;G`mV2
//Utility.log(in.readLine()); aI_[h v
sHeader=httpConnection.getHeaderFieldKey(i); "2z&9`VIY
if(sHeader!=null) a7n`(}?Y
{ 7[ZoUWx
if(sHeader.equals("Content-Length")) vE&K!k`
{ 9NeHN@D)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y@ X>ejk"
break; (CInt_dBw~
} .,<w_=
} P71] Z
else cyBm,!
break; !nL>Ly
} bi[g4,`Z;
} @|D#lBm
catch(IOException e){e.printStackTrace ();} {JQCfs
catch(Exception e){e.printStackTrace ();} D-LQQ{!D5
ag6[Nk
H @5dj}
Utility.log(nFileLength); Hq#q4Y
]DjnzClx
Scfe6+\EW
return nFileLength; </!GU*
} >f70-D28
aRy" _dZ2
jwmPy)X|s\
//保存下载信息（文件指针位置） B["jndyr
private void write_nPos() fLZ mQO
{ rqz48~\lJ
try{ QXEz[R
output = new DataOutputStream(new FileOutputStream(tmpFile)); {LBL8sG
output.writeInt(nStartPos.length); @]etW>F_
for(int i=0;i<nStartPos.length;i++) X}g"_wN,g>
{ IO7cRg'-F
// output.writeLong(nPos); m=rMx]k
output.writeLong(fileSplitterFetch.nStartPos); Hi nJ}MF
output.writeLong(fileSplitterFetch.nEndPos); -?w3j9kk>
} U#:N/ts*(
output.close(); 80K"u[
} (dwb{+HW
catch(IOException e){e.printStackTrace ();} RQU-]qQ8BM
catch(Exception e){e.printStackTrace ();} !uP8powO
} pZKK7
!m8T< LtMl
2=,d.1E3d
//读取保存的下载信息（文件指针位置） /0b7"Kr
private void read_nPos() W@RD bsc
{ XZrzG P(
try{ dF7`V J2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); duc\/S'
int nCount = input.readInt(); ET(/h/r
nStartPos = new long[nCount]; =^z*p9ZB
nEndPos = new long[nCount]; *onVG5<
for(int i=0;i<nStartPos.length;i++) ; W$.>*O
{ .E;}.X
nStartPos = input.readLong(); Ld 0j!II(
nEndPos = input.readLong(); `4wy *!]
} 0-p %.}GE
input.close(); 4kR;K!@k
} Q)\[wYMt
catch(IOException e){e.printStackTrace ();} h{ZK;(u$
catch(Exception e){e.printStackTrace ();} r,q.RWuII
} !LCy:>i!d
A4/gVi|
'p)DJUwt
private void processErrorCode(int nErrorCode) rpc;*t+z
{ ,6ae='=d
System.err.println("Error Code : " + nErrorCode); *ZIX76y<!A
} xeKm} MN]S
&%tW
pZ]&M@Ijp
//停止文件下载 <) -]'@*c
public void siteStop() 5=V29
{ SNf~%B?`L
bStop = true; &yI>A1
for(int i=0;i<nStartPos.length;i++) Oj8D+sC{
fileSplitterFetch.splitterStop(); $`P]%I}
:lu"14
bI8')a
} #mD_<@@
} ?rziKT5OOC
//负责部分文件的抓取 7Kpv fyL{
**FileSplitterFetch.java *+(eH#_2/
*/ ?Zb3M
package NetFox; 8:2Vib$
n8JM 0 U-
v1/Y0
import java.io.*; /#SH`ZK
import java.net.*; )1 QOA
9A87vs4[
/S@iF
public class FileSplitterFetch extends Thread { R G~GVf
di7cCn
kOC0d,
String sURL; //File URL -j1]H"-
long nStartPos; //File Snippet Start Position *?A!`JpJn
long nEndPos; //File Snippet End Position qRz /$|.
int nThreadID; //Thread's ID M"-.D;sa1
boolean bDownOver = false; //Downing is over |io)?`pj
boolean bStop = false; //Stop identical ?Ss~!38
FileAccessI fileAccessI = null; //File Access interface _C19eW'
40z1Qkmaey
/FjdcH=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 70EH~
{ \7IT[<Se
this.sURL = sURL; %*RZxR):
this.nStartPos = nStart; h92KU
this.nEndPos = nEnd; A`"?~_pHC
nThreadID = id; 4YoQ*NQw-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (W}DMcuSd
} G<]@nP{P
74&{GCL
"'/+}xM"5
public void run() ;P$ _:-C
{ qn'TIE.
while(nStartPos < nEndPos && !bStop) Sr_hD5!
{ [+="I &
^ > ?C
Z?WVSJUVf
try{ F`,Hf Cb\
URL url = new URL(sURL); :^`WrcOJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N8=-=]0G
httpConnection.setRequestProperty("User-Agent","NetFox"); lkC|g%f
String sProperty = "bytes="+nStartPos+"-"; IkxoW:L
httpConnection.setRequestProperty("RANGE",sProperty); -B(p8YH
Utility.log(sProperty); "xn,'`a
0fK#:6
N vTp1kI]
InputStream input = httpConnection.getInputStream(); `cIeqp
//logResponseHead(httpConnection); 0QxBC7`qp
E`{DX9^
[nlq(DGJhp
byte[] b = new byte[1024]; THB[(3q
int nRead; }5}>B *
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l.Z+.<@
{ nZG zez
nStartPos += fileAccessI.write(b,0,nRead); k_?~@G[I
//if(nThreadID == 1) `tcX[(`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]24]id
} B\% Gp}
G*~CB\K_
Xq"Es
Utility.log("Thread " + nThreadID + " is over!"); 9l:[jsk<d
bDownOver = true; BB ::zBg
//nPos = fileAccessI.write (b,0,nRead); ZwiXeD+4
} >%slzr
catch(Exception e){e.printStackTrace ();} }o\} qu*
} 6Q{OM:L/;.
} mS49l
!DV0u)k(
N P5K1:
//打印回应的头信息 .q!i +0
public void logResponseHead(HttpURLConnection con) H+@?K6{h
{ ~:|V,1
for(int i=1;;i++) |KO[[4b ?+
{ oa[O~z{~
String header=con.getHeaderFieldKey(i); K@:Ab'(P^|
if(header!=null) " BLJh)i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NbCIL8f]
Utility.log(header+" : "+con.getHeaderField(header)); P m&^rC;
else 5H|7DVG
break; 6E(..fo:"
} _c-(T&u<
} I]3!M`IMG
4vkqe6
?sR(
public void splitterStop() "9N;&^I
{ gA3f@7}d
bStop = true; }]<|`FNc
} @x;(yqOb
?crK613 t
l-x-
} c `.BN(
-rT#Wi
_::ssnG3jT
/* 2OqEyXh
**FileAccess.java OKk"S_`
*//文件访问(定位，写) tCA0H\';
package NetFox; W1ndb:
import java.io.*; rj?c
}([}A`@
/;!I.|j
public class FileAccessI implements Serializable{ Xn>>hzj-x?
(uC@cVkP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'Z%1Ly^b
RandomAccessFile oSavedFile; ->7zVAX
long nPos; 0F%?<: &
yL -}E
02,.UqCz
public FileAccessI() throws IOException \+0l#t$
{ ![J_6f}!
this("",0); .MID)PY-
} Tks"GlE*D
-lAY*2Jg
mAJ'>^`^
public FileAccessI(String sName,long nPos) throws IOException ={;+0Wjb8
{ m}S}fH(
oSavedFile = new RandomAccessFile(sName,"rw"); DF gM7if
this.nPos = nPos; @D `j
oSavedFile.seek(nPos); H<P d&
} hb %F"Q
{z;4t&5
" SP6o
public synchronized int write(byte[] b,int nStart,int nLen) A..`?oGj
{ !,]c}Y{i
int n = -1; -(ST
try{ $M+'jjnP
oSavedFile.write(b,nStart,nLen); LnsYtkbr
n = nLen; Z)@[N 6\?
} 9wO2`e )
catch(IOException e) bD|VT
{ rw0s$~'
e.printStackTrace (); W"CG&.
} S_RP&+!7
|Q";a:&$
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return n; Np+pJc1
} uY/CiTWr
{zLgLBM
Ai5+ ;8z+
} cR*~JwC:
q9a6s{,
sOS^
/* TqOH(={
**SiteInfoBean.java J(=y$8xje
*/ (N)>?r@n`
package NetFox; uK1VFW
a3a:H
q(1hY"S"}b
public class SiteInfoBean { K]|hkp&
3*(><<ZC
fE3%$M[V7
private String sSiteURL; //Site's URL ~@[<y1g?nG
private String sFilePath; //Saved File's Path /g!Xe]Ss
private String sFileName; //Saved File's Name xh!T,|IR
private int nSplitter; //Count of Splited Downloading File [qkc6sqo
&& PZ;
/V#?d
public SiteInfoBean() 'Z#>K*
{//nSplitter的缺省值为5 iWW >]3Q
//default value of nSplitter is 5 /WK1(B:
this("","","",5); P.1Z@HC
} V-X Ty iv
pqju@FD*
]k+(0qxG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c>+68<H
{ ,pQ[e$u1
sSiteURL= sURL; 2:e7'}\D.
sFilePath = sPath; x{Dw?6TP
sFileName = sName; 'R42N3|F
this.nSplitter = nSpiltter; \0&$n
A0v@L6m-O
j7NOYm5N
} Z J1@z.
!:tr\L {
I#7H)^us
public String getSSiteURL() D-x*RRkpp
{ Ra:UnA
return sSiteURL; vmo!
} [ <k&]Kv
BJ fBYH,M
t\Qm2Q)>
public void setSSiteURL(String value) Vh]=sd<F
{ X gtn}7N.
sSiteURL = value; ?wn<F}UH
} %|j`;gYV
If8 ^
%*IH~/Ld;]
public String getSFilePath() &SPr#OkW
{ ilZ5a&X;
return sFilePath; .1ep8O<
} #cb9g
wjT#D|soI
r/HG{XH`
public void setSFilePath(String value) Ea0EG>Y
{ \nL@P6X
sFilePath = value; 7_rDNK@e
} ~SsfkM"
|t;Ktl
=GeGlI6
public String getSFileName() #BZ5Mxzj
{ #Pg?T%('`
return sFileName; */$]kE
} f2v~: u
w]N;HlU
Qp2~ `hD
public void setSFileName(String value) #]^M/y h
{ F*NHy.Y
sFileName = value; dwiLu&]u
} ,">CPl]
y S<&d#:"
sAZL,w
public int getNSplitter() GSH,;cY
{ DQ0 UY
return nSplitter; GpR,n2
} %%h.`p1
m93{K7O2e
yHZ&5
public void setNSplitter(int nCount) Wv,?xm
{ 'kg~#cf/+
nSplitter = nCount; U2\k7I
} H;Gs0Qi;
} Lu[Hz8
v^[!NygShs
y'JJ#7O=
/* ]J/;Xp
**Utility.java D(e,R9hPU
*/ f;&XTF5D^
package NetFox; gAsjkNt?
e%0IEX
_LWMz=U=J/
public class Utility { x$S~>H<a
Cwji,*
E|6@h8#
public Utility() @9k/od@mW
{ \Z~ <jv
l9H-N*Wx
X6?Gxf,
} yDpv+6(a
t6)R37
//线程睡眠 M,Lq4bz
public static void sleep(int nSecond) ]a:T]x6'
{ l[nf"'
try{ *$mb~k^R
Thread.sleep(nSecond); !Uhcjfq`e
} 'w|N} 4
catch(Exception e) M?['HoRo
{ s(MdjWw
e.printStackTrace (); 90H/Txq
} cn9=wm\\
} E6-~
&G3$q,`H
//日志 }UG<_bE|
public static void log(String sMsg) (YYwn@NGj
{ z34+1d
System.err.println(sMsg); *r6v9
} J%E0Wd
1O90 ]c0
Ka"1gbJ|
public static void log(int sMsg) F@ZB6~T~.
{ @,pn/[
System.err.println(sMsg); H\|H]:CE
} Jb8%A@Z+
} Q:Y`^jP
Uz`OAb
U(<~("ocN
/* :~,V+2e
**TestMethod.java Mo4igP
*/ U a1Z,~ *
package NetFox; R>,_C7]u
qp/nWGj
asbFNJG{
public class TestMethod { 6N.MCB^
S&'-wAEd
LO)QEUG
public TestMethod() &tlU.Whk+
{ ///xx/weblogic60b2_win.exe g}I{-
try{ m khp@^5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,u.A[{@py
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1kh()IrA
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^pocbmg
fileFetch.start(); (abtCuZ8z
} >i2WYT
catch(Exception e){e.printStackTrace ();} b.xG'
-Z:nImqzc
d s}E|Q
} U H6 Jvt
2K{)8;^
9]a!1
public static void main(String[] args) -.UUa
{ *47%|bf`
new TestMethod(); +3-f$/po
} FF30VlJ
} /I0}(;^y
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