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)); Uu@qS
} B qINU
for(int i=0;i<nEndPos.length-1;i++) Ki1 zi~
{ ks69Z|D
nEndPos = nStartPos[i+1]; J*zQ8\f=}
} APJFy@l}
nEndPos[nEndPos.length-1] = nFileLength; !]9qQ7+R%
} _{ 2`sL)
} s'd\"WaQV
asE.!g?
+ rM]RFi
//启动子线程 bdvpH DA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;mr*$Iu7|
for(int i=0;i<nStartPos.length;i++) 0'Qvis[kt
{ X{[$4\di{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D51s)?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4/_!F'j
nStartPos,nEndPos,i); FW)~e*@8=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a[,p1}!_
fileSplitterFetch.start(); 5Q:49S47
} wzmQRn;s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :c Er{U8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B/mfm 7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h`eHoKJ#w
nEndPos = " + nFileLength); 56u_viZ=8
// fileSplitterFetch[nPos.length-1].start(); pV!WZUfg
c>! ^\
eht>4)
//等待子线程结束 <u1`o`|-
//int count = 0; ]l3Y=Cl
//是否结束while循环 C[l5[DpH
boolean breakWhile = false; g $^Yv4
Q~n%c7
&" 5Yt&{
while(!bStop) hBifn\dFr
{ 'Q=(1a11
write_nPos(); )c 79&S
Utility.sleep(500); bj_/
breakWhile = true; ka{!' ^
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2T@?&N^OD
for(int i=0;i<nStartPos.length;i++) (yeWArQ
{ k!x`cp
if(!fileSplitterFetch.bDownOver) *o!#5c
{ rt?*eC1b+Z
breakWhile = false; r^ '
break; K$s{e0 79
} ?%D nIl>
} ttt4h
if(breakWhile) /)dyAX(
break; A6E~GJa
H;DjM;be
B1%xU?
//count++; NSR][h_
//if(count>4) >7cDfv"
// siteStop(); r;>.*60AT
} |@f\[v9`
H:WuMwD4
o,?h}@
System.err.println("文件下载结束！"); /1bQ RI^\
} 9/I xh?
catch(Exception e){e.printStackTrace ();} 5)0'$Xxqa0
} F[)tg#}@G
*_HF%JYMZ
i'1MZ%.
//获得文件长度 N0ef5J JM`
public long getFileSize() ^V]IPGV
{ \>{;,f
int nFileLength = -1; ZqjLZ9?q
try{ o!c~"
URL url = new URL(siteInfoBean.getSSiteURL()); ]mC5Z6,1s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k\g:uIsv$
httpConnection.setRequestProperty("User-Agent","NetFox"); >LPIvmT4D?
5{vuN)K3
yb0Mn*X+ N
int responseCode=httpConnection.getResponseCode(); J: I@kM
if(responseCode>=400) I%B\Wy/j^
{ dOKe}?}==
processErrorCode(responseCode); mHH>qW{`
return -2; //-2 represent access is error 58eO|c(
} VtGZB3
h2i1w^f
1S yG
String sHeader; PY&mLux%
NK:! U
n?9FJOqi
for(int i=1;;i++) Z.s0ddMs
{ 2lqy<o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F6>oGmLy
//Utility.log(in.readLine()); .Sv/0&O
sHeader=httpConnection.getHeaderFieldKey(i); 7")~JBH
if(sHeader!=null) +wI<w|!
{ 8PWEQ<ev7>
if(sHeader.equals("Content-Length")) >Pvz5Hf/wW
{ b"B:DDw00
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,/!^ZS*
break; q0NToVo@
} *>xCX
} }d5~w[
else P'*Fd3B#A=
break; bL+}n8B
} \5Y<UJKi
} ~@T`0W-Py
catch(IOException e){e.printStackTrace ();} \p]B8hLW
catch(Exception e){e.printStackTrace ();} %joU}G;"
=hY/Yr%P
uf"(b"N0
Utility.log(nFileLength); jX^_(Kg
5du xW>D
;82?ACCP
return nFileLength; )t CNp
} :H+8E5
oArJ%Y>
Jb-.x_Bf
//保存下载信息（文件指针位置） ~qK/w0=j
private void write_nPos() QZ*gR#K]Sz
{ $+$l?2
try{ P]armg%
output = new DataOutputStream(new FileOutputStream(tmpFile)); p./0N.
output.writeInt(nStartPos.length); ;WgUhA ;q
for(int i=0;i<nStartPos.length;i++) OB*V4Yv
{ ?/myG{E
// output.writeLong(nPos); G.PRPl
output.writeLong(fileSplitterFetch.nStartPos); BfD&e`KI
output.writeLong(fileSplitterFetch.nEndPos); 1+YqdDqQ
} Z[eWey_
output.close(); 8(L6I%k*
} `3@?)xa
catch(IOException e){e.printStackTrace ();} @7KG0<]h
catch(Exception e){e.printStackTrace ();} $g/h=w@
} B&6lG!K'?
g(,^';j
tBX71d T
//读取保存的下载信息（文件指针位置） W+5. lf=2>
private void read_nPos() ml /S|`Drk
{ 1l Cr?
try{ II!~"-WH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3rjKwh7
int nCount = input.readInt(); +_+j"BT
nStartPos = new long[nCount]; d`=LZio
nEndPos = new long[nCount]; _ElG&hyp
for(int i=0;i<nStartPos.length;i++) 0m"Ni:KEf
{ NRgVNE
nStartPos = input.readLong(); yxU9W,D v
nEndPos = input.readLong(); sx}S,aIU
} `uH7~ r^
input.close(); [m%]C
} d ez4g
catch(IOException e){e.printStackTrace ();} 9%1J..c
catch(Exception e){e.printStackTrace ();} $2RSYI`py
} RBBmGZ
i'4.w?OZ
L"n)fe$
private void processErrorCode(int nErrorCode) K[LuvS
{ z?( b|v
System.err.println("Error Code : " + nErrorCode); fc9@l a
} .{} 8mFi1
C+[)^2M{
i^V(LGQF
//停止文件下载 Rn]xxa'
public void siteStop() c+ByEP4EG
{ o]<9wc:FZ
bStop = true; ^$sqU
for(int i=0;i<nStartPos.length;i++) HD/!J9&
fileSplitterFetch.splitterStop(); :9Jy/7/
T~(Sc'8
RHMXPsj
} ^_<|~
} 3 yy5 l!fv
//负责部分文件的抓取 TEMxjowr
**FileSplitterFetch.java ~!!|#A)W
*/ j49Uj}:j
package NetFox; M +r!63T
^|]Dg &N.
BP0:<vK{
import java.io.*; Y)+q[MZ R
import java.net.*; 8W?dWj
0GXY2+p}S
G3%Ju=
public class FileSplitterFetch extends Thread { )1KyUQ\e
. R/y`:1:W
nS*Y+Q^9a
String sURL; //File URL [nPs
long nStartPos; //File Snippet Start Position %0N HU`j
long nEndPos; //File Snippet End Position 9|#cjHf
int nThreadID; //Thread's ID ]L7A$sTUQ
boolean bDownOver = false; //Downing is over F!wz{i6\h
boolean bStop = false; //Stop identical FutS
FileAccessI fileAccessI = null; //File Access interface $ VP1(C
\'4~@
Wi'}d6c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +ovK~K$A
{ Cl]?qH*:
this.sURL = sURL; gtZmBe=
this.nStartPos = nStart; h%Nd89//
this.nEndPos = nEnd; J5I@*f)l
nThreadID = id; n]ba1t8ZA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >m,hna]RZ
} \`2'W1O
^hmV?a:Y
~<m^
public void run() P*OG`%y
{ ;*M@LP{*L
while(nStartPos < nEndPos && !bStop) [eDrjf3m
{ 89g a+#7
!S#3mT-
0lg$zi x(
try{ og5VB
URL url = new URL(sURL); % D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pc`d]*BYi
httpConnection.setRequestProperty("User-Agent","NetFox"); T8x)i\<
String sProperty = "bytes="+nStartPos+"-"; L(VFzPkY%
httpConnection.setRequestProperty("RANGE",sProperty); >+P}S@
Utility.log(sProperty); :*M?RL@j
A iM ukd,
Mh.1KI[t
InputStream input = httpConnection.getInputStream(); ,,gMUpL7_8
//logResponseHead(httpConnection); Zj2 si
?<EzILM
ew~Z/ A
byte[] b = new byte[1024]; @MES.g
int nRead; CO='[1"_5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g<W]NYm
{ Y 3BJ@sqz
nStartPos += fileAccessI.write(b,0,nRead); 73;Y(uh9
//if(nThreadID == 1) ](w)e p~;3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d:(Ex^^
} !C#oZU]P
d_yvG.#C
^l!SIu
Utility.log("Thread " + nThreadID + " is over!"); /?'~`4!(
bDownOver = true; G% tlV&In
//nPos = fileAccessI.write (b,0,nRead); {aY) Qv}
} qzUiBwUi@
catch(Exception e){e.printStackTrace ();} ]y_:+SHc
} tYu<(Z(l)
} |nefg0`rk
WNGX`V,d
MXaFqK<Y
//打印回应的头信息 An. A1y
public void logResponseHead(HttpURLConnection con) Z<nNk.G
{ 8G:/f3B=
for(int i=1;;i++) Lv%3 jj
{ 3 7BSJ
String header=con.getHeaderFieldKey(i); =!'9TS
if(header!=null) oy^-?+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pU7;!u:c4%
Utility.log(header+" : "+con.getHeaderField(header)); T+Z[&|
else @]l|-xGCWn
break; u#76w74
} Q,KNZxT,q
} ,1sbY!&ekL
uy{O
z%8`F%2
public void splitterStop() f24W*#IX
{ =XR~I
bStop = true; {-4+=7Sg1
} YSP\+ZZ
<?.eU<+O`S
X30tO>
} YV.' L
`UsJaoR#f
g *Js4
/* :^)?AO#J
**FileAccess.java vi##E0,N'^
*//文件访问(定位，写) KuJ)alD;1
package NetFox; $JY\q2
import java.io.*; XoKgs,y4
HMd?`
cY5&1Shb~
public class FileAccessI implements Serializable{ <x}wy+SG
0s;~9>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2.v{W-D[
RandomAccessFile oSavedFile; +=($mcw#[
long nPos; r2RJb6
@[r[l#4yUi
&#PPXwmR
public FileAccessI() throws IOException 5M5Bm[X
{ _lv{8vf1B
this("",0); U"GxXrl
} !aT:0m$:9c
OJe!K:
X8ap
public FileAccessI(String sName,long nPos) throws IOException ujxr/8mjV
{ Cty#|6k
oSavedFile = new RandomAccessFile(sName,"rw"); -:ucp2
this.nPos = nPos; WuUwd#e
oSavedFile.seek(nPos); e9[72V
} uZKP"Oy
%!Q`e79g8
xh@-g|+g
public synchronized int write(byte[] b,int nStart,int nLen) $.St ej1
{ 2Nc>6
int n = -1; _+f+`]iM
try{ k5d\w@G"~
oSavedFile.write(b,nStart,nLen); ?z-}>$I;
n = nLen; iP~,n8W
} BG2)v.CU
catch(IOException e) JHn*->m
{ i@"e,7mSG
e.printStackTrace (); c/W=$3
} ug 7o>PX
n7LfQWc
}w-wSkl1
return n; <g8K})P
} n;XWMY
8U2dcx:G3
(3vHY`9
} u9-nt}hGYM
1,y&d}GW
t/i5,le
/* e=P
**SiteInfoBean.java a.F Al@Br
*/ }7<5hn E
package NetFox; 01a-{&
Q<tu)Qo
>gtQw!
public class SiteInfoBean { uw\1b.r'B
)+I.|5g
&`|:L(+
private String sSiteURL; //Site's URL K5Wg"^AHY/
private String sFilePath; //Saved File's Path : DG)g3#
private String sFileName; //Saved File's Name &UHPX?x
private int nSplitter; //Count of Splited Downloading File W><Zn=G4)b
M s9E@E
&YP#M|
public SiteInfoBean() igf)Hb;5
{//nSplitter的缺省值为5 QA!_} N4n
//default value of nSplitter is 5 =64r:E
this("","","",5); EfLO5$?rm
} OY-w?'p?W
\b8sG"G
C=Fzu&N}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W~T}@T:EN
{ YO)$M-]>%J
sSiteURL= sURL; d87vl13
sFilePath = sPath; 59uwB('|lH
sFileName = sName; n]W_e
this.nSplitter = nSpiltter; }n,Zl>T9
\h<BDk*
txql 2
} -a Gcf]6
}0hL~i
MWk:sBCqr
public String getSSiteURL() W" "*ASi
{ ]Hj<IvG
return sSiteURL; 1xJ TWWj-
} Gnm4gF!BI
~%u|[$
gCd`pi 8
public void setSSiteURL(String value) {Ee>n^1
{ rtJl _0`
sSiteURL = value; TZir>5
} [//R~i?
m%+IPZ2m
8qi+IGRg
public String getSFilePath() cR-~)UyrO
{ ulHn#)
return sFilePath; 0XwHP{XaO
} z!QDTIb
@(``:)Z<b
;Lw{XqT
public void setSFilePath(String value) "yziXT@V
{ >>[/UFC)n
sFilePath = value; WzW-pV]
} Uv_N x10
LgmvKW|
fHrt+_Zn|
public String getSFileName() #yseiVm;
{ FFhtj(hVgc
return sFileName; q+SD6qM
} }y%`)lz~;
{eJt,[Y *
6Q4X6U:WB
public void setSFileName(String value) 3T\l]? z
{ eC DIwB28
sFileName = value; |9xI_(+{kP
} ymY1o$qWB}
LVIAF0kX
i[C~5}%
public int getNSplitter() .Hhhi
{ >$677
return nSplitter; D\~zS`}
} +j+5ud`
9CGNn+~YI
{ kSf{>Ia
public void setNSplitter(int nCount) + Y.1)i}
{ S|V4[ssB
nSplitter = nCount; seFGJfN\?f
} oq/G`{`\
} D(W,yq~7uY
pY)5bSA
g3n'aD@'x
/* #$~ba%t9%
**Utility.java a`9L,8Ve
*/ ))D:8l@
package NetFox; |rw%FM{F
wCs^J48=
Eh</? Qv\
public class Utility { j*@l"V>~
ha@L94Lq
p=GWq(S6
public Utility() mpC`Yk
{ vgt]:$
-hcS]~F
nZ1zJpBmI
} k-V,~c
A,-6|&F
//线程睡眠 ]=rht9),"
public static void sleep(int nSecond) @53k8
{ 8*SDiZ
try{ gXT9 r' k
Thread.sleep(nSecond); 4!Z5og1kn
} !!`!|w
catch(Exception e) 2UFv9
{ (Nx;0"5IX
e.printStackTrace (); KN7n@$8YM
} V\^EfQ
} m"o ;L3
/ew Ukc8,
//日志 EpFQ|.mQ
public static void log(String sMsg) @O[}QB?/fi
{ p\JfFfC
System.err.println(sMsg); hED=u/ql[
} 6Qx#%,U^ J
_` [h,=
6Vbzd0dk
public static void log(int sMsg) Y2[A2Uy$ef
{ 1 `7<2w
System.err.println(sMsg); fI7j):h;
} nxJee=qH
} ]D!k&j~P
2EK%N'H
PccB]
/* ZJjTzEV%^B
**TestMethod.java n 8pt\i0
*/ F>X-w+b4r
package NetFox; SgEBh
7HHysNB"w
vw)7 !/#
public class TestMethod { u?[ q=0.J7
\i[BP
\bx~*FaX
public TestMethod() 3s>'hn
{ ///xx/weblogic60b2_win.exe "z*:'8;E
try{ }BmS)Jq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6ITLGA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m"9XT)N
SiteFileFetch fileFetch = new SiteFileFetch(bean); WpLZQ6wH
fileFetch.start(); /S\cU`ZVe
} AC.A'|"]i
catch(Exception e){e.printStackTrace ();} "aF8l<1xn
cM_Fp
S',9g4(5
} "W#t;;9Wz
pfd#N[c
}N*>QR5K
public static void main(String[] args) L@^~N$G&u
{ 5`<eKwls
new TestMethod(); s:AkkkF
} =q"eU=9
} `PL[lP-<
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