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)); CQ$::;
} /M]eZ~QKD
for(int i=0;i<nEndPos.length-1;i++) k*OvcYL1A
{ %`eJ66T
nEndPos = nStartPos[i+1]; /Ht/F)&P
} e& p_f<
nEndPos[nEndPos.length-1] = nFileLength; @~s~/[
} h)^dB,~
} RA}U#D:$i
wLpkUa
8H7O/n
//启动子线程 k)|'JDm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZWFG?8lJ
for(int i=0;i<nStartPos.length;i++) #n=A)#'my
{ [f=.!\0\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {v,{x1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), })KJ60B
nStartPos,nEndPos,i); 5Yn{?r\#F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,TEuM|
fileSplitterFetch.start(); @W#fui<<}Y
} LSSW.Oz2L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %V31B\]Nz7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L 43`^;u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ut]2`8-
nEndPos = " + nFileLength); 6zv;lx0<D&
// fileSplitterFetch[nPos.length-1].start(); amMjuyW
GKiq0*/M
{=s:P|ah
//等待子线程结束 "havi,m
//int count = 0; ob)Q,;8R
//是否结束while循环 D DQs42[
boolean breakWhile = false; sw[oQ!f
{>wI8
m"<4\;GK
while(!bStop) 1B6C<cL:sU
{ 8~.iuFp
write_nPos(); ';&0~[R[
Utility.sleep(500); .N/GfR`0/<
breakWhile = true; |O57N'/
/8=:qIJYA
m5)EQE}gPp
for(int i=0;i<nStartPos.length;i++) xLe =d|6
{ B*y;>q "{U
if(!fileSplitterFetch.bDownOver) h (qshbC}
{ 0{-`Th+h
breakWhile = false; #fwzFS \XL
break; Ica3
} mm_^gQ,`
} xIM8
if(breakWhile) =Na/3\^WP
break; *e%Dg{_
K?9WY]Ot
/X@7ju;
//count++; 5.O-(eSa0&
//if(count>4) 2dXU0095
// siteStop(); ;0;3BH A
} "fRlEO[9
{EOn r1
C5>{Q:.`e'
System.err.println("文件下载结束！"); XI]OA7Zis
} Y_$^:LG
catch(Exception e){e.printStackTrace ();} = vY]G5y
} &1*4%N@'
be&6kG
h0T< :X
//获得文件长度 c=jcvDQ6W
public long getFileSize() NR;q`Xe-
{ '&N: S-
int nFileLength = -1; 2_Pz^L
try{ ^a086n
URL url = new URL(siteInfoBean.getSSiteURL()); N =x]AC,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BHF{-z
httpConnection.setRequestProperty("User-Agent","NetFox"); 2^cAK t6bC
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#D/$6ah~m
int responseCode=httpConnection.getResponseCode(); 's=Q.s
if(responseCode>=400) `kqT{fs
{ d|>9rX+f
processErrorCode(responseCode); c zZrP"
return -2; //-2 represent access is error se~ *<5
} :|?~B%-p[
5OPS&:
?+bTPl;%'
String sHeader; Tf9&,!>V
*d^9,GGn-
WA<H
for(int i=1;;i++) mw:3q6
{ )W[KD,0+j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QV`X?m
//Utility.log(in.readLine()); OI'uH$y
sHeader=httpConnection.getHeaderFieldKey(i); u86J.K1Q
if(sHeader!=null) g ^D)x[
{ JOA%Y;`<#
if(sHeader.equals("Content-Length")) :X3rd|;kc
{ \%w7D6dEZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \B*k_W/r@
break; #rh0r`
} {fAh@:{@
} (jp1; #P!
else xnl<<}4pJ
break; {;]uL`abi?
} :`{9x%o;
} *raIV]W3
catch(IOException e){e.printStackTrace ();} #cw! &
catch(Exception e){e.printStackTrace ();} nvU+XCx
Ytl:YzXCi
@#bBs9@gv
Utility.log(nFileLength); [37f#p
VaD:
OwNAN
return nFileLength; #gxRTx
} 1.hOE>A%
+9<,3IJe6
0-8ELX[#
//保存下载信息（文件指针位置） ~*66 3pA
private void write_nPos() |usnY
{ XS}Zq4H
try{ <ol$-1l#9
output = new DataOutputStream(new FileOutputStream(tmpFile)); /.pa ??u
output.writeInt(nStartPos.length); ^%~Et>C
for(int i=0;i<nStartPos.length;i++) 3&.TU5]`-
{ FiV^n6-F`
// output.writeLong(nPos); >GdLEE'w
output.writeLong(fileSplitterFetch.nStartPos); 9`LU=Xv/
output.writeLong(fileSplitterFetch.nEndPos); 7VEt4
} Ig40#pA
output.close(); E'S<L|A/
} 8.Pcr<
catch(IOException e){e.printStackTrace ();} eLHa9R{)B
catch(Exception e){e.printStackTrace ();} Z&~k]R0y
} =2ATqb"$w
kcg)_]~6
Wh#_9);
//读取保存的下载信息（文件指针位置） iqU.a/~y
private void read_nPos() !nP8ysB
{ cHqvkN`
try{ TzD:bKE&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o=a:L^nt,
int nCount = input.readInt(); "Qiq/"h
nStartPos = new long[nCount]; 9*GL@_c
nEndPos = new long[nCount]; sg!=Q+
for(int i=0;i<nStartPos.length;i++) c]cO[T_gGa
{ J@u!S~&r
nStartPos = input.readLong(); S>/I?(J
nEndPos = input.readLong(); +1JZB*W
} =$:4v`W0(
input.close(); Ymrpf
} n:}MULy;
catch(IOException e){e.printStackTrace ();} [*mCa:^
catch(Exception e){e.printStackTrace ();} rsIt~w
} a=}">=]7
x|~D(zo
`Cb<KAaCH
private void processErrorCode(int nErrorCode) K8Kz
{ 2i4Dal
System.err.println("Error Code : " + nErrorCode); K'{wncumQ
} e!:?_z."
.@x"JI>;
'vf,T4uQ"
//停止文件下载 ,M+h9_&0?
public void siteStop() S7\|/h:4
{ ;6\Ski0=l
bStop = true; e>)}_b
for(int i=0;i<nStartPos.length;i++) >mGGJvTx
fileSplitterFetch.splitterStop(); `Tm8TZd66
tyGnG0GK
^{6UAT~!R
} gZ79u
} ~gzpX,{n
//负责部分文件的抓取 hj#+8=
**FileSplitterFetch.java #!<+:y'S?
*/ %r}KvJgd
package NetFox; V,"AG
\fQgiX
%n V@'3EI
import java.io.*; r*
import java.net.*; sDh6 Uk
v J,xz*rc`
hQW#a]]V:
public class FileSplitterFetch extends Thread { $[^ KCNB
=t>`<T|(
ZRVF{D??"%
String sURL; //File URL -*]9Ma<wa
long nStartPos; //File Snippet Start Position &bOodkOb
long nEndPos; //File Snippet End Position +kdU%Sm
int nThreadID; //Thread's ID Ff1M~MhG
boolean bDownOver = false; //Downing is over *{4{<O<4
boolean bStop = false; //Stop identical sN[@mAoH
FileAccessI fileAccessI = null; //File Access interface >P]I&S-.
H$($l<G9C
={&TeMMA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `[W)6OUCx}
{ ,2:L{8_L
this.sURL = sURL; !&`7
this.nStartPos = nStart; ="[+6X
this.nEndPos = nEnd; tg m{gR
nThreadID = id; }O-%kl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hzf}_1
} dT0z^SG
5SPl#*W
*rMN,B@
public void run() |RbUmuj
{ _o=`-iy9
while(nStartPos < nEndPos && !bStop) {t IoC;Y
{ n6-!@RYr
fPuQ,J2=
5x L,~"
try{ x:D<Mu#
URL url = new URL(sURL); `&&6-/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); neMe<jr
httpConnection.setRequestProperty("User-Agent","NetFox"); .q& ]wu
String sProperty = "bytes="+nStartPos+"-"; ,r)d#8
httpConnection.setRequestProperty("RANGE",sProperty); mrBhvp""
Utility.log(sProperty); [4(A458H
R/KWl^oNj
I$P7%}
InputStream input = httpConnection.getInputStream(); w]}cB+C+l#
//logResponseHead(httpConnection); JeSkNs|vB
u[% J#S
?[|4QzR
byte[] b = new byte[1024]; 3By>t!~Q
int nRead; "9Fv!*<-W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0z2R`=)
{ E4fvYV_ra
nStartPos += fileAccessI.write(b,0,nRead); W9V=hQ2
//if(nThreadID == 1) ,?skJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *~aI>7H
} CI]U)@\U
hE3jb.s(>
qcoZ2VJ hh
Utility.log("Thread " + nThreadID + " is over!"); Sv]"Y/N
bDownOver = true; Z(clw
//nPos = fileAccessI.write (b,0,nRead); &G5I0:a
} @eD~FNf-]
catch(Exception e){e.printStackTrace ();} oFx gR9
} f\%X7.
} xVmUmftD
u*YuU%H=
L bK1CGyA
//打印回应的头信息 K {N;k-
public void logResponseHead(HttpURLConnection con) ,2L,>?r6
{ tYxlM!
for(int i=1;;i++) qb/!;U_
{ Y&:\s8C
String header=con.getHeaderFieldKey(i); <zWQ[^
if(header!=null) Bf}0'MK8zQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r-DD*'R
Utility.log(header+" : "+con.getHeaderField(header)); 4xC6#:8
else j1C0LP8
break; g&20F`.N*>
} ~#xs `@{s
} JL*]9$o
(6_/n&mF
u=N;P
public void splitterStop() |HIA[.q
{ kys-~&@+
bStop = true; 53#5p;k
} Sf8Xj|u
iO#xIl<
a\.?{/
} +/^q"/f F
&b:Zln.j
#B{F{,vlu,
/* @!tmUme1c
**FileAccess.java 2/W0y!qh1
*//文件访问(定位，写) e&I.kC"j6
package NetFox; R~u7;Wv
import java.io.*; D}=i tu
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u(Q(UuI
public class FileAccessI implements Serializable{ _!T$|,a
p5 PON0dS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z-=7QK.\{
RandomAccessFile oSavedFile; &]A1 _dy
long nPos; +.Ukzu~s
P>cJ~FM
Lgw@y!Llij
public FileAccessI() throws IOException o`]FH_
{ +Gs;3jC^
this("",0); m^&mCo,
} *^m.V=
h!3Z%M
0>J4O:k
public FileAccessI(String sName,long nPos) throws IOException o?x|y
{ W5yu`Br
oSavedFile = new RandomAccessFile(sName,"rw"); +2enz!z#k
this.nPos = nPos; r/w@Dh]{_
oSavedFile.seek(nPos); -&^(T
} {nWtNyJpS
D%}o26K.C
DWO:
public synchronized int write(byte[] b,int nStart,int nLen) 0iq$bT|
{ z~;qDf|I
int n = -1; { ^k,iTx
try{ W_lNvzag
oSavedFile.write(b,nStart,nLen); z?g4^0e
n = nLen; k3eN;3#&
} zm.sX~j
catch(IOException e) '4S@:.D`
{ JVYYwA^.
e.printStackTrace (); B_1u<00kg
} 0pG(+fN_9
"lya|;
.=<pU k 3G
return n; ) FsSXnZL
} $G.|5sEk
U9%nku4
)O'<jwp$
} f;6d/?=~
=?x=CEW
\M^4DdAy
/* M& L0n%,y5
**SiteInfoBean.java MH(g<4>*
*/ Y&%0 eI!
package NetFox; SQvB)NOw
EnAw8Gm*
JG$J,!.\
public class SiteInfoBean { vUExS Z^
zL}DLfy>R
uvd>
private String sSiteURL; //Site's URL 0{uX2h
private String sFilePath; //Saved File's Path 'v5gg2
private String sFileName; //Saved File's Name J~6*d,Ry`
private int nSplitter; //Count of Splited Downloading File iIRigW
ioQlC4Y
jt*@,+e|
public SiteInfoBean() uQ)]g
{//nSplitter的缺省值为5 !9Ni[8&Fg0
//default value of nSplitter is 5 =v;@w$#
this("","","",5); nQMN2jM
} $l0w{m!P
6d6SP)|j
7qp|Msf},
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cViCWc2
{ XS@6jbLE
sSiteURL= sURL; jR:Fih-}
sFilePath = sPath; *2hzReM
sFileName = sName; u{^Kyo#v
this.nSplitter = nSpiltter; Ml ^Tb#
xEqrs6sR
P40eK0e6
} |'#NDFI>}
~d]7 Cl
6UTdy1Qq>
public String getSSiteURL() T9yW# .
{ X[}%iEWzT
return sSiteURL; P@ u%{
} $tJJ >"
U^I'X7`r
2sH5<5G'
public void setSSiteURL(String value) [0emOS
{ 73X]|fy
sSiteURL = value; (Nf.a4O
} I Cs1=
?*0kQo'
*!kg@ _0K
public String getSFilePath() jXQ_7
{ b6ddXM\Z
return sFilePath; X"sN~Q.0
} TM;)[R@
WfVie6
Z^3Risi
public void setSFilePath(String value) dLq!t@?iu>
{ -1:asM7
sFilePath = value; W\ckt]'
} /r6DPR0\
J^T66}r[f,
ub&1L_K
public String getSFileName() L $~Id
{ lHU$A;
return sFileName; YDwns
} qJsEKuOs
,??|R`S
p%_TbH3j`
public void setSFileName(String value) AKVmUS;70
{ SF7Kb`>Y
sFileName = value; 622).N4
} pWqahrWh
~[{| s')
,>Q,0bVhH0
public int getNSplitter() *4bV8T>0Z
{ 7pNh|#Uv'
return nSplitter; h7{W-AtM7_
} G[mYx[BTz
6=FuH@Q&
G(- `FH
public void setNSplitter(int nCount) }z[se)s
{ Ic*Q(X
nSplitter = nCount; u|C9[(
} f]EHDcC3X
} sQkP@Y
!Kis,e
DbDpdC;
/* /i<g>*82
**Utility.java [3s~Z8 pP
*/ nz(OHh!}u
package NetFox; `'/8ifKz
Z-p_hNb
Z-:`{dns/
public class Utility { F{[Q
8[k-8h|
Gs%kqD{=
public Utility() iR9iI!+;N
{ B0:O]Ax6.^
q/Q*1
e:#\Oh
} @RjLDj+)S
v{9eEk1
//线程睡眠 A[oRi}=
public static void sleep(int nSecond) n1QO/1} :
{ >\e11OU0Gy
try{ >y?$aJ8ZV
Thread.sleep(nSecond); <K43f#%
} Bn.8wMB
catch(Exception e) /1Eg6hf9B
{ SF6n06UZu
e.printStackTrace (); z)ydQw>
} ms?h/*E<H
} J-U}iU|
V\ |b#?KL
//日志 09Fr1PL
public static void log(String sMsg) 7-^d4P+|g
{ Ne=D$o
System.err.println(sMsg); w$pv
} xN5}y3
j/sZ:Q
Co'dZd(
public static void log(int sMsg) U@9n7F
{ 6 R!0v8
System.err.println(sMsg); uB%`Bx'OW
} # RtrHm
} G B15
j9Lc2'
n7S[ F3
/* 3V-pLs|
**TestMethod.java $I_aHhKt
*/ 0j*8|{|
package NetFox; aJub("
xHf l>C'
noacnQ_I$
public class TestMethod { YcIk{_N3
/t816,i
E]68IuP@'
public TestMethod() s>kzt1,x
{ ///xx/weblogic60b2_win.exe v8LKv`I's
try{ x{=ty*E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +;vfn>^!b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B"G;"X
SiteFileFetch fileFetch = new SiteFileFetch(bean); /vBpRm
fileFetch.start(); +Ta7b)
} 6%)dsTAB
catch(Exception e){e.printStackTrace ();} !4|7U\;
=ahD'*R^A
*b> ~L
} X@TQD
)s!x)< d;
]]Wa.P~]O
public static void main(String[] args) =|H/[",gg
{ LNe-]3wB
new TestMethod(); !dZC-U~
} d8av`m
} =l {>-`:
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