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)); mI*>7?
} [==Z1Q;=
for(int i=0;i<nEndPos.length-1;i++) ;DWp>jgy
{ .0/Z'.c8
nEndPos = nStartPos[i+1]; YuW\GSV00
} aNEy1-/(\
nEndPos[nEndPos.length-1] = nFileLength; :jp$X|
} /hy!8c7
} N=q29JU
.j@n6RyN
?At-
//启动子线程 &(1NOyX&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !ZcALtq
for(int i=0;i<nStartPos.length;i++) m!>'}z
{ -5*;J&.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]=$ay0HC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CUM~*
nStartPos,nEndPos,i); Y2$`o4*3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qMj e,Y
fileSplitterFetch.start(); B_G7F[/K
} ~a|Q[tiV]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~Q\uP(!D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R^C;D2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5~6y.S
nEndPos = " + nFileLength); Sk%|-T(d$
// fileSplitterFetch[nPos.length-1].start(); VL1z$<vVXt
yc}t(*A5
g9Qxf%}
//等待子线程结束 O!yn `<l
//int count = 0; U?C{.@#w
//是否结束while循环 r>eXw5Pr7
boolean breakWhile = false; gVWLY;c 3}
`Hu;Gdj=
+Uk.|@b=-V
while(!bStop) R-|]GqS}L
{ !(tJZ5
write_nPos(); PQ|x?98
Utility.sleep(500); he6) L6T
breakWhile = true; {u][q &n
q/zdd3a
M:M<bz Vu
for(int i=0;i<nStartPos.length;i++) ps J 1J
{ >b${rgCvQ
if(!fileSplitterFetch.bDownOver) NP/2gjp
{ 6u8fF|s
breakWhile = false; 0pz X!f1~
break; 6lFsN2
} c9={~
} hY'%SV p
if(breakWhile) t`{Fnf
break; <H#K`|Ag
^9E(8DD
(J#3+I
//count++; 4h(Hy&1C
//if(count>4) );LwWKa
// siteStop(); ?Fw/c0
} 4\RuJx
yh!vl&8M
zW.sXV,
System.err.println("文件下载结束！"); ShxX[k
} &*-2k-16
catch(Exception e){e.printStackTrace ();} Grv|Wuli
} ,B!Qv3bn
<GEn9;\
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//获得文件长度 \aozecpC`
public long getFileSize() aT[7L9Cw
{ }(6k7{,Gw,
int nFileLength = -1; "yk%/:G+
try{ Aed"J5[a
URL url = new URL(siteInfoBean.getSSiteURL()); :r=_\?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VVOt%d
httpConnection.setRequestProperty("User-Agent","NetFox"); 2e=Hjf )
G}*B`m
RPQ)0.O7
int responseCode=httpConnection.getResponseCode(); ya=51~ by"
if(responseCode>=400) yFqC-t-i
{ f|)t[,c
processErrorCode(responseCode); Qa+gtGtJ
return -2; //-2 represent access is error ^(3k uF
} ?;Qk!t2U
/zKuVaC
WBIS
String sHeader; h'+ swPh
?0X.Ith^.
\8ZNXCP
for(int i=1;;i++) hpu(MX\
{ =G :H)i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5[k35c{
//Utility.log(in.readLine()); ,8seoX^
sHeader=httpConnection.getHeaderFieldKey(i); he#iWD'
if(sHeader!=null) mLSAi2Y
{ 0Og =H79<
if(sHeader.equals("Content-Length")) EQ -\tWY
{ 4j5 "{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FqfeH_-U
break; U@WT;:.T
} {H74`-C)W
} ]M/w];:
else wpdT "
break; \=JKeL|6[S
} pFh2@O
} `/O_6PQ}
catch(IOException e){e.printStackTrace ();} l;4F,iI
catch(Exception e){e.printStackTrace ();} fi1UUJ0 U;
Jx]`!dP3
!TcjB;q'
Utility.log(nFileLength); P<1zXs.H
s$;v )w$
Tym!7H2
return nFileLength; 6 S8#[b
} G+ToZ&f@
JG `QJ%
.dV!du
//保存下载信息（文件指针位置） YL]x>7T~4t
private void write_nPos() 7K~=QEc
{ fXN;N&I
try{ N.]8qzW
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?^5x d1>E
output.writeInt(nStartPos.length); 01J.XfCd6
for(int i=0;i<nStartPos.length;i++) uAP|ASH9T
{ Q["}U7j
// output.writeLong(nPos); hikun2
output.writeLong(fileSplitterFetch.nStartPos); ;]gph)2cd
output.writeLong(fileSplitterFetch.nEndPos); /CP1mn6H
} J<2N~$
output.close(); @S{,g;8
} y(HR1vQ;Z
catch(IOException e){e.printStackTrace ();} jm!G@k6TA
catch(Exception e){e.printStackTrace ();} yR&E6o.$z
} =8]'/b
^U52 *6
: v]< h
//读取保存的下载信息（文件指针位置） MkQSq MU=
private void read_nPos() QS[%`-dR2
{ 1t6UI4U!$
try{ cla4%|kq3Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j%lW+[%
int nCount = input.readInt(); iVD9MHT4
nStartPos = new long[nCount]; E @7! :
nEndPos = new long[nCount]; [mhY_Hmz]
for(int i=0;i<nStartPos.length;i++) "|hmiMdGB
{ [bAv|;
nStartPos = input.readLong(); {2,V3*NF
nEndPos = input.readLong(); ZEB1()GB
} ?O.&=im_
input.close(); ?wmr~j
} hHdC/mR
catch(IOException e){e.printStackTrace ();} J &c}z4
catch(Exception e){e.printStackTrace ();} aw(P@9]
} JI.ad_IR
wJ{M&n1H
ex-`+cF
private void processErrorCode(int nErrorCode) 46*?hA7@r(
{ _r&#Snp
System.err.println("Error Code : " + nErrorCode); ce@(Ct
} vJYy`k^Y
KNV$9&Z
&AW?!rH
//停止文件下载 ztf(.~
public void siteStop() !dZHG R
{ rXA7<_Vg
bStop = true; ^K3{6}]
for(int i=0;i<nStartPos.length;i++) Zf|f $1-
fileSplitterFetch.splitterStop(); k+&|*!j
67d0JQTu
&D/_@\ 0
} +&|WC2#
} \i{=%[c
//负责部分文件的抓取 $L?stgU
**FileSplitterFetch.java #bnFR
*/ 98x(2fCvF(
package NetFox; qUCiB}
.t\5H<z
A\WgtM
import java.io.*; FX\ -Y$K
import java.net.*; U:ZklDW
.x}ImI
DI+kO(S
public class FileSplitterFetch extends Thread { Ry,jPw5<
^/c&Ud
)PZ'{S
String sURL; //File URL zL1H[}[z+
long nStartPos; //File Snippet Start Position -8g ;t3z
long nEndPos; //File Snippet End Position (ZDRjBth[
int nThreadID; //Thread's ID --y.q~d
boolean bDownOver = false; //Downing is over R:=i/P/
boolean bStop = false; //Stop identical HdLVXaD/
FileAccessI fileAccessI = null; //File Access interface d!!5'/tmS
SZEX;M
w<5w?nP+Oh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oMcX{v^"
{ +.{_n(kU
this.sURL = sURL; FD[*mCGZ
this.nStartPos = nStart; Z?X ^7<
this.nEndPos = nEnd; pS9CtQqvgy
nThreadID = id; EY':m_7W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /8lGP!z
} .BZw7 YV
5WY..60K,
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public void run() P$\(Bd\76
{ bc%7-%
while(nStartPos < nEndPos && !bStop) RytQNwv3
{ +Nyx2(g<m
cvi+AZ=
Bm1yBKjO
try{ KD=T04v
URL url = new URL(sURL); az\;D\\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #NwlKZ-
httpConnection.setRequestProperty("User-Agent","NetFox"); >PfYHO
String sProperty = "bytes="+nStartPos+"-"; uG~%/7Qt{
httpConnection.setRequestProperty("RANGE",sProperty); Jy{A1i@4~s
Utility.log(sProperty); gtJUQu p2
%.[t(F
$D1Pk
InputStream input = httpConnection.getInputStream(); e$fxC-sZ
//logResponseHead(httpConnection); qbpvTTF
YB.r-c"Y
9["yL{IPe
byte[] b = new byte[1024]; |&o%c/
int nRead; 3L/>=I{5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8}nA8J
{ ^3F[^#"
nStartPos += fileAccessI.write(b,0,nRead); 26&^n Uy
//if(nThreadID == 1) +kmPQdO;*/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JstX# z
} M n3cIGL
Cir==7A0
dt<PZ.
Utility.log("Thread " + nThreadID + " is over!"); n@Y`g{{e~
bDownOver = true; z{7&=$
//nPos = fileAccessI.write (b,0,nRead); zH.DyD5T;
} T1LtO O
catch(Exception e){e.printStackTrace ();} \2*<Pq
} rX)PN3TD
} ]@)X3}"!
y/'2WO[
0,{Dw9W:
//打印回应的头信息 S2@[F\|r
public void logResponseHead(HttpURLConnection con) OIe {Sx{y
{ !Z`~=n3bk
for(int i=1;;i++) oOnk,U
{ ,g;~:
String header=con.getHeaderFieldKey(i); H*?U@>UU
if(header!=null) >| rID
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y}R{A6X)
Utility.log(header+" : "+con.getHeaderField(header)); a{mtG{Wc
else }[SWt3qV1
break; o5-oQ_j
} 5M;fh)fT
} -"UK NB!
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public void splitterStop() TwqyQ49
{ ]3BTL7r
bStop = true; =hH>]$J[
} O&!+ni
Ola>] 0l
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} !vHnMY~AG
?kI-o0@O.
{Nuwz|Ci
/* l`UJHX
**FileAccess.java k3da*vwE
*//文件访问(定位，写) _>9|"seR
package NetFox; FVPhk2
import java.io.*; @0;9.jml,
8$io^n\i
Ia=wf"JS)
public class FileAccessI implements Serializable{ hWfJh0I
;cH|9m:Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M}k )Ep9
RandomAccessFile oSavedFile; DN2K4%cM%'
long nPos; s4<[f%^
'ejuzE9
@NWjYHM[`
public FileAccessI() throws IOException >Vy=5)/i
{ /pan{.< k
this("",0); 2 :u4~E3
} F#Uxl%h
\rY|l
@s}I_@
public FileAccessI(String sName,long nPos) throws IOException 0(VH8@h`O
{ !@{_Qt1
oSavedFile = new RandomAccessFile(sName,"rw"); s3HwBA
this.nPos = nPos; kj~)#KDN
oSavedFile.seek(nPos); 0}2Uj>!i
} Oh9wBV
uc<XdFcu
iJv4%|9
public synchronized int write(byte[] b,int nStart,int nLen) d/!sHr69
{ GMU.Kt
int n = -1; f50qA;7k
try{ PX65Z|~>_
oSavedFile.write(b,nStart,nLen); [X ]\^
n = nLen; Wp/!;
} ck>|p09q'9
catch(IOException e) :0$(umW@I"
{ 3Bee6N>
e.printStackTrace (); %H75u6
} }00mJ]H(
pN6!IxN$
I~\j%zD
return n; .\= GfF'
} gRIRc4p
5\8Ig f>
!/znovoD
} D-\\L[
Ap9CQ h=!
M,"4r^%k
/* q{@j$fMt0
**SiteInfoBean.java BoYWx^VHx^
*/ :P#
package NetFox; ;ZPAnd:pb
yx"xbCc#
e;~[PYeu
public class SiteInfoBean { 4SCb9|/Q
~z#Faed=a
3.U5Each-
private String sSiteURL; //Site's URL b2u_1P\
private String sFilePath; //Saved File's Path m663%b(5>
private String sFileName; //Saved File's Name )` -b\8uw
private int nSplitter; //Count of Splited Downloading File S1(. AI~
..V6U"/
dFD0l?0N
public SiteInfoBean() A<2_V1
{//nSplitter的缺省值为5 gm~Ka%O|F
//default value of nSplitter is 5 !31v@v:)
this("","","",5); jo{[*]Oa
} i`Fg kABw
c) Zid1
G 5w:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mj=$[y(
{ YqX/7b+
sSiteURL= sURL; tX$%*Uy
sFilePath = sPath; ]S9~2;2^,
sFileName = sName; L$6{{Tw"2
this.nSplitter = nSpiltter; .>DqdtP[
H8.U#%
jv<BGr=4;
} KArt4+31
cJj4qXF
EL$l . v
public String getSSiteURL() :"7V,UP @
{ -twV?~f
return sSiteURL; = zW}vm }
} Q!(16
>M[wh>
Zc(uK{3W-
public void setSSiteURL(String value) M@EML @~
{ -8;U1^#
sSiteURL = value; x~C%Hp*#
} [}q6bXM*
fvK):eCo
}D/0&<1
public String getSFilePath() ^_ L'I%%[
{ PCDsj_e
return sFilePath; E9TWLB5A)(
} v?BX 4FO
^55#!/9
wR +C>
public void setSFilePath(String value) q|BR-0yi
{ f{MXH&d 1\
sFilePath = value; (b%&DyOt
} H4p N+
PB00\&6H
z}&w7O#
public String getSFileName() "_t2R &A
{ U|VFzpJ
return sFileName; &QFg=
} nylrF"'e
oG~a`9N%C
l\<*9m<
public void setSFileName(String value) {^zieP!
{ k44sV.G4L
sFileName = value; k2DT+}u7G
} B 3<T#
ee}&~%
- `F#MN
public int getNSplitter() ,paD/
{ '*H&s
return nSplitter; ? hU0S
} _1_CYrUc
78&(>8@m
:E'uV"j%
public void setNSplitter(int nCount) w&<-pIa`
{ @)=\q`vV
nSplitter = nCount; F_0vh;Jo
} &?C% -"|c
} gFlUMfKh
h^o>9s/|/H
EwDFUK
/* 6S7 =+>
**Utility.java S_?{<{
*/ .`qw8e}y#'
package NetFox; :k9n 9
| LdDL953
gI<e=|J6w
public class Utility { W&>ONo6ki
V ':?rEN|
9>,$q"M}?
public Utility() <^>O<P:v
{ 1KwUp0%&
^y:!=nX^
w5zrEk#
} pJ)PVo\cV
g2Pa-}{
//线程睡眠 sk*AlSlM
public static void sleep(int nSecond) #+dF3]X(&
{ #nG?}*#
try{ TY,5]*86I&
Thread.sleep(nSecond); 5WJof`M
} Q'-g+aN
catch(Exception e) S5B12P
{ W &wqN
e.printStackTrace (); ,pfHNK-u
} +pDZ,c,
} \/=w\Tj
w}2;f=
//日志 rjsqXo:9
public static void log(String sMsg) J3/2>N]/}
{ es]S]}JV
System.err.println(sMsg); xZ2^lsY
} G&ZpQ)
7nr+X Os
D}4*Il?
public static void log(int sMsg) q6E8^7RtS@
{ up`.#GWm
System.err.println(sMsg); .CU~wB@h
} qu>5 rg-
} %&EDh2w>
OJX* :Q
%K@s0uQ
/* 79}voDFd
**TestMethod.java `*?8<Vm
*/ k)l*L1Y4:
package NetFox; :yPA6O 4
*WS'C}T
N0U6N< w
public class TestMethod { gN"Abc
xOfZ9@VU
v(Vm:oK,
public TestMethod() [+7Nu
{ ///xx/weblogic60b2_win.exe #fT1\1[]
try{ kl4u]MyL#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -w7g}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Hzos$1DJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); @C\>P49
fileFetch.start(); 5Z (1&
} 4(2iR0N
catch(Exception e){e.printStackTrace ();} aX`@WXK
e* 2ay1c
,V$PV,G
} "v%|&@
_4!SO5T
;4E(n
public static void main(String[] args) F|Y}X|x8Q
{ J2tD).G
new TestMethod(); Xgq-r $O2X
} IvJ;9d
} YGAB2`!U
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