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)); 5@f5S0 Y
} l"\uf(0K
for(int i=0;i<nEndPos.length-1;i++) @GeHWv
{ %{'4. ,
nEndPos = nStartPos[i+1]; vpLMhf`
} wW5Yw i
nEndPos[nEndPos.length-1] = nFileLength; T*+A.G@L"
} D^?_"wjW
} (STx$cya
1<,/ -H
V^rW?Do
//启动子线程 mH\@QdF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rQj~[Y.c
for(int i=0;i<nStartPos.length;i++) S(t{&+Wc
{ Y/lN@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RxG^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ri+U0[e3
nStartPos,nEndPos,i); DsQ/aG9c%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ac\W\=QvB
fileSplitterFetch.start(); mx}E$b$<CY
} OKPJuV`y6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d)KF3oA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `{}@@]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r/PKrw sC
nEndPos = " + nFileLength); . #U}q 7X
// fileSplitterFetch[nPos.length-1].start(); c#pj:f*H
ny1 \4C
PAoX$q
//等待子线程结束 w~N-W8xNR
//int count = 0; j04/[V)
//是否结束while循环 w+_Wc~f
boolean breakWhile = false; hk;bk?:m
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f:vD`Fz1
while(!bStop) sFElD ]|
{ /b{HG7i\
write_nPos(); ~6d5zI4\
Utility.sleep(500); fSI%c3
breakWhile = true; Le&;g4%
eP= j.$
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for(int i=0;i<nStartPos.length;i++) l%<c6;
{ sykFSPy`'
if(!fileSplitterFetch.bDownOver) %U?)?iZdL
{ oAz<G
breakWhile = false; )4ncutb
break; ,` o+ ?
} HNMBXXf,B
} g1V)$s7
if(breakWhile) (\& 62B1
break; $G3@< BIN
5"gL.Ez
ZNL5({lv
//count++; }Vl^EAR
//if(count>4) g;G5 r&T
// siteStop(); 5hz_P+Q
} !*bdG(pK
^ItAW$T]F
vgAFuQi(
System.err.println("文件下载结束！"); 2sun=3qb
} L[.<o{
catch(Exception e){e.printStackTrace ();} u){S$</
} /7vE>mSY
(9'be\
6t$N78U
//获得文件长度 w4A#>;Qu*
public long getFileSize() BS.=
{ fTgbF{?xh
int nFileLength = -1; {aIZFe}B
try{ 8Fx]koP.
URL url = new URL(siteInfoBean.getSSiteURL()); 3?^NN|xg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Cc :)
httpConnection.setRequestProperty("User-Agent","NetFox"); JMePI%#8
:D4];d>1
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int responseCode=httpConnection.getResponseCode(); UM\}aq=,
if(responseCode>=400) qK-qcPLsl
{ vv* |F
processErrorCode(responseCode); r0uJ$/!
return -2; //-2 represent access is error R8ZD#,;
} rXDJ:NP
I4:rie\hjC
5"uNj<.V
String sHeader; tWX7dspx/
f}blB?e
`#p< rfe
for(int i=1;;i++) C[0MA ,^
{ e# <4/FR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]CIe~q
//Utility.log(in.readLine()); +Lhe,
sHeader=httpConnection.getHeaderFieldKey(i); f-&ATTx`J
if(sHeader!=null) :mn(0 R~
{ $>![wZ3
if(sHeader.equals("Content-Length")) T+(M8qb
{ n{$}#NdV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lJlhl7
break; ?(>k,[n
} G ~A$jStm
} Q-3r}jJe
else XJ O[[G`
break; BPh".RJ
} uct=i1+ fE
} V07VwVD
catch(IOException e){e.printStackTrace ();} re/xs~
catch(Exception e){e.printStackTrace ();} .Nk}Z9L]k
{x9j_/R
R qnWtE
Utility.log(nFileLength); 3Qk/ Ll
[0wP\{%
^glX1 )
return nFileLength; m^'~&!ba
} rykj2/O
3hH>U%`-
el}hcAY/RP
//保存下载信息（文件指针位置） Q7L)f71i
private void write_nPos() *!i,?vn
{ "cNg:
try{ & \JLTw
output = new DataOutputStream(new FileOutputStream(tmpFile)); K[*h+YO
output.writeInt(nStartPos.length); Shs')Zsbv
for(int i=0;i<nStartPos.length;i++) z1kBNOr
{ ::v;)VdX+*
// output.writeLong(nPos); ^)Smv\Md
output.writeLong(fileSplitterFetch.nStartPos); 4{Q$!O>
output.writeLong(fileSplitterFetch.nEndPos); JaA&eT|
} ]F !'M
output.close(); J`4Z<b53
} -!@H["
catch(IOException e){e.printStackTrace ();} UE\%e9<l
catch(Exception e){e.printStackTrace ();} N`f!D>b:dn
} DE'Xq6#PK
Ih(:HFRMq6
SwyaYK
//读取保存的下载信息（文件指针位置） h]<GTWj
private void read_nPos() s;anP0-O
{ ?0 HR(N(z!
try{ J0&zb'1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0K&_D)
int nCount = input.readInt(); $I\))*a
nStartPos = new long[nCount]; xT:qe
nEndPos = new long[nCount]; WfRVv3Vm
for(int i=0;i<nStartPos.length;i++) MgHOj
{ uPI v/&HA
nStartPos = input.readLong(); [SK2x4
nEndPos = input.readLong(); ,;9ak-$8p
} 2=jd;2~
input.close(); \)FeuLGL9
} f#*h^91x
catch(IOException e){e.printStackTrace ();} Jw2B&)k/
catch(Exception e){e.printStackTrace ();} Y,3z-Pa=@
} 9 aY'0wa
W^^K0yn`@
^!q 08`0
private void processErrorCode(int nErrorCode) &/ \O2Aw8
{ X'YfjbGo
System.err.println("Error Code : " + nErrorCode); Xq+!eOT
} .UNF~}^H
g7.7E6%H
N<p5p0
//停止文件下载 sGXp}{E9
public void siteStop() <l*agH-.3
{ @~JB\j9
bStop = true; 7bctx_W&6
for(int i=0;i<nStartPos.length;i++) 0eQ~#~j&
fileSplitterFetch.splitterStop(); aeEw#
pGO|~:E/L
lF0K=L
} Gtj(
} 9yh9HE
//负责部分文件的抓取 z8 hTZU
**FileSplitterFetch.java "9c.CI
*/ Q2JdO 6[96
package NetFox; 6Hc H'nmeN
p>2||
;n%]*v
import java.io.*; ST[2]
import java.net.*; pem3G5 `g=
'CP/ymf/a
r^?)F?n!
public class FileSplitterFetch extends Thread { `'z(--J}`
\4[c}l
FZ[@])B
String sURL; //File URL *>H M$.?Q
long nStartPos; //File Snippet Start Position CBiU#h q
long nEndPos; //File Snippet End Position <dju6k7uz
int nThreadID; //Thread's ID B'WCN&N
boolean bDownOver = false; //Downing is over 7P3<o!YA
boolean bStop = false; //Stop identical Ha46U6_'h
FileAccessI fileAccessI = null; //File Access interface hgTM5*fD}
XNc"kp? z
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [VY8?y
{ r Iya\z1W
this.sURL = sURL; ig2{lEkF
this.nStartPos = nStart; hQgk.$g
this.nEndPos = nEnd; 2ApDpH`fiJ
nThreadID = id; ga4/,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F/Rng'l
} _n-VgPRn
&{-oA_@
,!o\),N
public void run() t9Enk!@
{ sDLVYD
while(nStartPos < nEndPos && !bStop) _&k'j)rg
{ X_lUD?y
bE7(L $UF
R&u)=~O\5
try{ e67c:Z
URL url = new URL(sURL); -XS+Uv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R-r+=x&
httpConnection.setRequestProperty("User-Agent","NetFox"); KuIt[oM
String sProperty = "bytes="+nStartPos+"-"; @+0@BO12
httpConnection.setRequestProperty("RANGE",sProperty); Ze$^UR
Utility.log(sProperty); u+2xrzf
<Um1h:^
}aHB$}"!
InputStream input = httpConnection.getInputStream(); ..P=D <'f
//logResponseHead(httpConnection); x'E'jh%
TIK/%T
N>&{Wl'y\
byte[] b = new byte[1024]; ImUQ*0
int nRead; dCf'\@<<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) htUy2v#V
{ >cwJl@wx-
nStartPos += fileAccessI.write(b,0,nRead); p=8M0k
//if(nThreadID == 1) jQ.>2-;H9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EuKrYY]g
} 'Yaf\Hp
LW83Y/7
^D]7pe
Utility.log("Thread " + nThreadID + " is over!"); boC>N
bDownOver = true; ct2_N
//nPos = fileAccessI.write (b,0,nRead); p?Z+z
} 2 Ft0C2
catch(Exception e){e.printStackTrace ();} t7C!}'g&'
} 9}%~w(P
} %KabyvOl)
.-C+0L1j
mFgb_Cd
//打印回应的头信息 haEZp6Z
public void logResponseHead(HttpURLConnection con) d+YVyw.z
{ 7(A G]
for(int i=1;;i++) ]HNT(w@
{ q_9N+-?{7
String header=con.getHeaderFieldKey(i); )9A<fwpN
if(header!=null) J[& 7,}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #GDh/t2@
Utility.log(header+" : "+con.getHeaderField(header)); 3&a*]
else zCj*:n
break; ]Vf8mkDGO
} Q^1#xBd
} ?vht~5'
vjs|!O=oH
!~|"LA!jn
public void splitterStop() ySr091Q
{ &geOFe}R
bStop = true; :N*q;j>
} Sq?6R}q%
O9qKwn;q(
:r vO8.\
} T_(e(5
FM;;x(sg
~Me&cT8
/* Yn[EI7D
**FileAccess.java WoClTb>F
*//文件访问(定位，写) HAI1%F236
package NetFox; fr,CH{Uq
import java.io.*; R uFu,H-
8,H#t@+MT
%`s9yRk9>E
public class FileAccessI implements Serializable{ HkfSx rTgQ
I).^,%>Z)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "u,~yxYWl
RandomAccessFile oSavedFile; P60]ps!M
long nPos; t;e]L'z@:
2\z`G
HhQPgjZ/
public FileAccessI() throws IOException )qe$rD;N
{ soQv?4
this("",0); 4Ow Vt&
} zhR_qW+
>ihe|WN
*\~kjZ 3
public FileAccessI(String sName,long nPos) throws IOException +}G>M=t::
{ AVevYbucB
oSavedFile = new RandomAccessFile(sName,"rw"); ++p& x{
this.nPos = nPos; Tm~#wL +r
oSavedFile.seek(nPos); p-(ADQS
} "` ?Wu
{L2Gb(YLW
7"CH\*%
public synchronized int write(byte[] b,int nStart,int nLen) ! 4^L $
{ R=Ly49
int n = -1; C"m0"O>
try{ HU'`kimWb
oSavedFile.write(b,nStart,nLen); n]ppO U|[
n = nLen; ^)0{42!]
} kmwrv -W
catch(IOException e) 6'sFmC
{ <GFB'`L
e.printStackTrace (); <hF~L k ,
} hDkqEkq1R
%ucmJ-<y#
b8b PK<
return n; 9:Z~}yX
} +KwF U
/jL{JF>I
5_tK3Q8?
} m+gG &`&u
)'I<xx'1
iN9!?Ov_
/* *ej o6>
**SiteInfoBean.java v%8-Al^G
*/ Y"\T*lKa
package NetFox; 1oW]O@R
fvBC9^3
uxJiec`&
public class SiteInfoBean { 6pz:Lfd80
xY}j8~k
<n~g+ps
private String sSiteURL; //Site's URL ;eEtdoy
private String sFilePath; //Saved File's Path Nm:<rI,^
private String sFileName; //Saved File's Name ;51!aC
private int nSplitter; //Count of Splited Downloading File 7u3b aM
ib=^tK
@U.}Ei
public SiteInfoBean() _TcQ12H 5<
{//nSplitter的缺省值为5 IEsD=
//default value of nSplitter is 5 0}C}\1
this("","","",5); Y&Vbf>Hi+
} T^H) lC#R
o?hw2-mH
|/Q."d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OuIW|gIu0
{ LYT<o FE-
sSiteURL= sURL; cZ2, u,4
sFilePath = sPath; b6$A@b
sFileName = sName; WoG
this.nSplitter = nSpiltter; pO+wJ|f
a|{<#<6n(
eS%6hUb
} O*Pe[T5x'
;}9Ws6#XQs
cZF;f{t
public String getSSiteURL() r|BKp,u9
{ b020U>)v
return sSiteURL; #"YWz)8
} GIl{wd
@y2Bq['
eOO*gM=
public void setSSiteURL(String value) ,r,;2,;6nd
{ bD[W~ku
sSiteURL = value; 5{f/H] P
} Bq=](<>>
sWzXl~JbF
DQXx}%Px
public String getSFilePath() Uy'ZL(2
{ EGO@`<"h
return sFilePath; BqAwo
} _^$b$4)
g {wPw
! r\ktX
public void setSFilePath(String value) `.Q3s?1F
{ RwHXn]1
sFilePath = value; ?bi^h/f
} @ MoMU
I}3K,w/7mi
Ev ,8?
public String getSFileName() ^Iq.0E9_
{ z]_CFo1'l
return sFileName; 5 :>
} :WTvP$R
Z'M@DY/fdK
SvJ8Kl OV
public void setSFileName(String value) U.jMK{
{ UZ0O j5B.
sFileName = value; NT:>.~ah@&
} !-Q!/?
U^S:2
)Em,3I/.l
public int getNSplitter() ~/[N)RFD
{ 82l";;n4p
return nSplitter; v)pWx0l=
} f}d@G/L
(Gsg+c
zOp"n\
public void setNSplitter(int nCount) (jMp`4P
{ CBHWMetJ*
nSplitter = nCount; ~<R~Q:T
} 2l%iXK[
} P3>2=qK"E(
^ZBkt7
B}T72!a
/* Pk2"\y@q/
**Utility.java @35]IxD
*/ 0nn#U
package NetFox; |%9~W^b
6?~pjMV
m8`A~
public class Utility { pswppC6f
3N\X{za
%QkvBg*
public Utility() 1yf&ck1R
{ SS-
7MfvU|D[d/
Vt>E\{@[t
} W5 }zJ)x
m 9Q{)?J7
//线程睡眠 .!! yj,bQz
public static void sleep(int nSecond) ?whp_
{ T[J_/DE@
try{ 0eIR)#j*
Thread.sleep(nSecond); -z94>}Z=
} J0o[WD$Ax
catch(Exception e) IS~oyFS
{ "b;?2_w:E
e.printStackTrace (); W3kilhZ
} MDt4KD+bZ
} wVB8PO8
VI{1SIhfa
//日志 P'';F}NwfX
public static void log(String sMsg) !Ai;S
{ \zU R9h
System.err.println(sMsg); P*Nl3?T
} 8iB}a\]B
>@o*v*25
9EW 7,m{A
public static void log(int sMsg) 9`{cX
{ *G38N]|u6
System.err.println(sMsg); LgYzGlJp
} Ig2VJs;
} $6[]c)(
L K$hV"SYb
shRvwE[
/* w6tY6bf}
**TestMethod.java >#Yq&@G
*/ hB4.tMgZ
package NetFox; muLTYgaM
l;fH5z
!.A>)+AK
public class TestMethod { PC5FfX
JP]K\nQx'
}HzZj;O^2>
public TestMethod() b~p <
{ ///xx/weblogic60b2_win.exe ( KrIMZ
try{ iJK9-k~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hV%l}6yS&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zq#o8))4X
SiteFileFetch fileFetch = new SiteFileFetch(bean); $}829<gh7
fileFetch.start(); HD>{UU?
} _<8y^ymo
catch(Exception e){e.printStackTrace ();} okW3V}/x/z
aNz%vbh\
&N#)(rQ1
} ^/,s$dj
w K+2;*bI
pfG:PrZ
public static void main(String[] args) QZY(S*Up
{ UTz;Sw?~hw
new TestMethod(); "T'!cy
} `@90b4u
} q:'(1y~
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