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)); 2AdV=n6Z
} gXF.e.uU
for(int i=0;i<nEndPos.length-1;i++) P ^D\znvc
{ No h*1u*
nEndPos = nStartPos[i+1]; h<}4mo_$
} ^c/.D*J[I
nEndPos[nEndPos.length-1] = nFileLength; -ERDWY
} JWEqy+,Fjw
} 9_&.G4%V
QYg2'`(
x=9drKIw>
//启动子线程 B>JRta;hj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iptzVr#b[
for(int i=0;i<nStartPos.length;i++) Bf8 #&]O
{ a*o=,!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UD.$C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b2ZKhS8
nStartPos,nEndPos,i); VRT| OUq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -`A6K!W&~p
fileSplitterFetch.start(); &L;0%
} RU@`+6j+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pvcD 61,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &t`l,]PQ=6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lh .p`^v
nEndPos = " + nFileLength); {6RT&w
// fileSplitterFetch[nPos.length-1].start(); `Up3p24
2'N%KKmJL
B1\}'g8%f
//等待子线程结束 Yz[^?M%(D
//int count = 0; 3>-^/
//是否结束while循环 }]/"auk
boolean breakWhile = false; 2x t 8F
zsWYV n]
f BukrPsV
while(!bStop) GsxrqIaD
{ q.~_vS%
write_nPos(); Kc0KCBd8];
Utility.sleep(500); *Z<`TB)<X
breakWhile = true; pYH#Vh
s_u@8e 6_
va| 1N/&
for(int i=0;i<nStartPos.length;i++) LG@5Z-
{ L%Me wU0TZ
if(!fileSplitterFetch.bDownOver) oS, %L
{ =M>pL+#
breakWhile = false; F!'y47QD
break; tpU[KR[-
} *i&ks>4N
} bF<FX_}!s!
if(breakWhile) 8|HuxE
break; }H\wed]F/
M2{{B^*$6
' FF@I^O
//count++; REli`"bR
//if(count>4) oBpHmMzA
// siteStop(); 4Y;z46yM%
} iJT_*,P^
)Z,O*u*
g>cp;co9g
System.err.println("文件下载结束！"); =:uK$>[
} X=8y$Yy
catch(Exception e){e.printStackTrace ();} }f/ 1
} )|zLjF$
Etj@wy/E
~#C7G\R
//获得文件长度 9-5H~<}fF
public long getFileSize() 4v_<<l
{ FxW~Co
int nFileLength = -1; 3)3?/y)_
try{ jEo)#j];`<
URL url = new URL(siteInfoBean.getSSiteURL()); 59 R;n.Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !#Ub*qY1Z
httpConnection.setRequestProperty("User-Agent","NetFox"); i]Njn k
scT,yNV
$qV, z
int responseCode=httpConnection.getResponseCode(); V9mqJRFJ:
if(responseCode>=400) \C#XKk$OE
{ \QGh@AQp"
processErrorCode(responseCode); Y{ijSOl3
return -2; //-2 represent access is error 49W@?:b
} yb\T<*
sIJl9
C8W#$a
String sHeader; 2<q>]G-nN
=^\yE"a
zmB6Y t
for(int i=1;;i++) &{-r 5d23
{ m<}>'DT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6#hDj_(,
//Utility.log(in.readLine()); IOhJL'r
sHeader=httpConnection.getHeaderFieldKey(i); UuPXo66F]
if(sHeader!=null) V"K-aO&
{ XYj!nx{k,
if(sHeader.equals("Content-Length")) ])`w_y(>
{ %Ya%R@b}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W8,4LxH
break; Ve)P/Zz}^
} GJS3O;2*
} D~P3~^
else hg4d]R,
break; tpPP5C{
} RUco3fZ
} >}?jOB
catch(IOException e){e.printStackTrace ();} A{NKHn>%`
catch(Exception e){e.printStackTrace ();} 4&N#d;ErC
Pw+PBIGn4
JbX"K< nQ
Utility.log(nFileLength); Mu: y9o95
}:+SA
QP>tu1B|
return nFileLength; IyK^` y
} 6Ft?9 B(F:
0gTv:1F/
Rxb?SBa
//保存下载信息（文件指针位置） 3u[m? Vw
private void write_nPos() lDsT?yHS`Z
{ nQ*9E|Vx
try{ X\4d|VJ?m
output = new DataOutputStream(new FileOutputStream(tmpFile)); fJ<I|ZZ
output.writeInt(nStartPos.length); iq1HA.X(
for(int i=0;i<nStartPos.length;i++) .bYZkO:oy
{ &X3G;x2;
// output.writeLong(nPos); 2i0 .x
output.writeLong(fileSplitterFetch.nStartPos); 3']a1\sy^
output.writeLong(fileSplitterFetch.nEndPos); <$z6:4uN_
} W>#[a %R
output.close(); # RoJD:9
} NVnId p
catch(IOException e){e.printStackTrace ();} L!;"73,&(8
catch(Exception e){e.printStackTrace ();} r+:]lO
} C GN=kQ
YN]xI
$;iMo/
//读取保存的下载信息（文件指针位置） c!0u,6
private void read_nPos() Ms=5*_J2Jk
{ =M6Ph%
try{ \rj>T6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d6^:lbj
int nCount = input.readInt(); eR3v=Q
nStartPos = new long[nCount]; kI?+\k\V`
nEndPos = new long[nCount]; u*}ltR~/
for(int i=0;i<nStartPos.length;i++) YuXCRw9p;
{ <?Ln`,Duk
nStartPos = input.readLong(); pl}nbY
nEndPos = input.readLong(); C]EkVcKFA
} *c<6 Er>s
input.close(); OI^??joQ
} ^ YOCHXg
catch(IOException e){e.printStackTrace ();} PfR|\{(
catch(Exception e){e.printStackTrace ();} 2t7P| b~V1
} g?.y7!m
]SC|%B_*
R?t_tmKXC!
private void processErrorCode(int nErrorCode) <uYrYqN
{ 4%B0H>
System.err.println("Error Code : " + nErrorCode); #Z. QMWq
} o;TS69|D
pKtN$Fd
J8'1 ~$6
//停止文件下载 ?kIyo
public void siteStop() "hmLe(jo}
{ '@/1e\-y
bStop = true; -1{f(/
for(int i=0;i<nStartPos.length;i++) ;A6%YY
fileSplitterFetch.splitterStop(); +0ALO%G;G"
_`I}"`2H
*z'v
} WKAG)4
} T>hrKn.!D:
//负责部分文件的抓取 ?:tk8Kgf
**FileSplitterFetch.java gc\/A\F<
*/ <78*-Ob
package NetFox; 5jq @ nq6
kzk8b?rOA
jn4|gQ
import java.io.*; "4IrW6B$9
import java.net.*; ^sKdN-{
(_%l[:o6
s\zY^(v4
public class FileSplitterFetch extends Thread { 3,'LW}
qRSoF04!R
N~uc%wOA
String sURL; //File URL S zNZY&8 f
long nStartPos; //File Snippet Start Position Bs`mzA54
long nEndPos; //File Snippet End Position ?edf$-"z/
int nThreadID; //Thread's ID p*j>s\
boolean bDownOver = false; //Downing is over 0q4PhxR`e
boolean bStop = false; //Stop identical 0q28Ulv9
FileAccessI fileAccessI = null; //File Access interface *sQ.y {
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P{LS +.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2 g\O/oz
{ *knN?`(x
this.sURL = sURL; CNe(]HIOH
this.nStartPos = nStart; kQ]4Bo
this.nEndPos = nEnd; |:.s6a#(
nThreadID = id; 2"T b><^"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YqmsL<
} znB+RiV8
O>N/6Z
IgjPy5k
public void run() aGOS9
{ R$!]z(
while(nStartPos < nEndPos && !bStop) (*M0'5
{ W__Y^\~
Ee_?aG e&
:t9sAD
try{ qnHjwMi
URL url = new URL(sURL); _&(L{cFx6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =),O;M
httpConnection.setRequestProperty("User-Agent","NetFox"); VX*+:
String sProperty = "bytes="+nStartPos+"-"; 8[.&ca/[
httpConnection.setRequestProperty("RANGE",sProperty); S}fQis
Utility.log(sProperty); dU*$V7
\!hd|j?&6
ZbiC=uh
InputStream input = httpConnection.getInputStream(); # >I_
//logResponseHead(httpConnection); Hs$HeAp;
ZeY|JH1
rizjH+
byte[] b = new byte[1024]; C=CZtjUt
int nRead; $}IG+,L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w_V A:]j4
{ _xH<R
nStartPos += fileAccessI.write(b,0,nRead); TQ:h[6v
//if(nThreadID == 1) Buso `G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [MQ* =*
} G)^/#d#&
!vSq?!y6*P
nGwon8&]]
Utility.log("Thread " + nThreadID + " is over!"); #6 ni~d&0
bDownOver = true; *3P+K:2lNG
//nPos = fileAccessI.write (b,0,nRead); }D+ b`,
} -+u}u=z%
catch(Exception e){e.printStackTrace ();} =>lX brJ
} ; wxmSX9
} |'&$VzA
5Ok3y|cEx
x4PzP
//打印回应的头信息 bI3GI:hp
public void logResponseHead(HttpURLConnection con) i#^YQCy
{ d2NFdBoI
for(int i=1;;i++) j/Y]3RSMp
{ WVsj
String header=con.getHeaderFieldKey(i); =L@CZ"
if(header!=null) %I9f_5BlT8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U}4I29M
Utility.log(header+" : "+con.getHeaderField(header)); Kxa1F,dZ
else YM#MfL#
break; wfe4b
} w N`Njm9!
} FfxD=\
&SPY'GQ!
pH.&C 5kA
public void splitterStop() i-;#FT+Xc
{ mI{Fs|9h
bStop = true; JWaWOk(t=?
} '^C *%"I]
Qe7=6<
mR1b.$
} [3qH?2&
(]\p'%A)
TQKcPVlE
/* wdf;LM
**FileAccess.java 0>Td4qr+u
*//文件访问(定位，写) N P+vi@Ud
package NetFox; {$Uj&/IC
import java.io.*; F-b]>3r
bcvm]aPu
|c8\alw
public class FileAccessI implements Serializable{ !;mn]wR>a
iLJ@oM;2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yGNpx3H
RandomAccessFile oSavedFile; ^n<YO=|u
long nPos; U^|T{g+O
3uxf n=E
%FM26^
public FileAccessI() throws IOException h~]e~u V
{ S[q:b .
this("",0); 9d^m 7}2
} J=78p#XUg
)+'=Zvgej=
[<{r~YFjWW
public FileAccessI(String sName,long nPos) throws IOException rm ;U'&{
{ v4Rci^8
oSavedFile = new RandomAccessFile(sName,"rw"); 9B;WjXSe
this.nPos = nPos; [zm@hxym
oSavedFile.seek(nPos); ~]RfOpq^w
} ;,6C&|n]w
-0<vmU
sbX7VfAR`
public synchronized int write(byte[] b,int nStart,int nLen) C|Y[T{g?t
{ nA_'jl
int n = -1; ZklpnL*!
try{ 0{%@"Fb0O
oSavedFile.write(b,nStart,nLen); QW,:'\G
n = nLen; ^^7@khmNl
} mD.6cV
catch(IOException e) {]8|\CcY?
{ (y6q}#<
e.printStackTrace (); -`{W~yz
} h!JyFc
%AtT(G(n
L7aVj&xM
return n; s@iY'11
} l1lYb;C
Yq51+\d
IO9|o!&>
} :L+xEL
Rc{R^5B
a%U#PF6
/* 6,jCO@!
**SiteInfoBean.java (B$>o.(JA
*/ Y$"m*0
package NetFox; T(Q ~b
dmXfz D
wT- <#+L\
public class SiteInfoBean { =H23eOS_#
J ;z`bk^
l3ogMRq@
private String sSiteURL; //Site's URL Kw;gQk~R!
private String sFilePath; //Saved File's Path ^7? WR?!
private String sFileName; //Saved File's Name _V1:'T8
private int nSplitter; //Count of Splited Downloading File GRYw_}Aa
w{dRf!b69
M&hNkJK*G
public SiteInfoBean() 'R'hRMD9o
{//nSplitter的缺省值为5 d7G@Z|R3p
//default value of nSplitter is 5 <`=Kt[_BQ
this("","","",5); VVAcbAGJ
} HBvyX`-
.TdFI"Yn
Ri`6X_xU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R= mTJ'y
{ ^o _J0 ]m
sSiteURL= sURL; ^78N25RU(
sFilePath = sPath; ;Wy03}K4J
sFileName = sName; a?nK|Q=e
this.nSplitter = nSpiltter; YJHb\Cf.
`Rfe*oAf
5NN;Fw+
} )4qspy3
fU ;H
c CDT27@
public String getSSiteURL() |5dNJF8;Q
{ 6Y\TVRR
return sSiteURL; W).Kq-
} Gvdok<o
/D;ugc*3
:vEfJSA 1<
public void setSSiteURL(String value) 1;<Vr<.
{ x+za6e_k"
sSiteURL = value; 56c[$ q
} 5vR])T/S0
z&9MkbH1
O.QR1
public String getSFilePath() `W@jo~y<
{ DjN1EP\Xx
return sFilePath; M\k[?i
} u&S0
G;vj3#u?
y0T#Qq
public void setSFilePath(String value) 65O 8?I
{ fUY05OMZ
sFilePath = value; /%,aX[
} s:xJ }Ll
Z8ivw\|M8
tKe-Dk9
public String getSFileName() 9)S3{i6w
{ zb4@U=?w}
return sFileName; +2eri_p
} 9Xa.%vw>
. 70=xH
Wp:vz']V
public void setSFileName(String value) 11#b%dT
{ Ut'T!RD
sFileName = value; ,:J[|9
} #&r}J
d oEuKT
yFmy
public int getNSplitter() o^(I+<el
{ uK(]@H7~!c
return nSplitter; n CX{tqy
} eXnSH$uI
$,/E"G`
N3\RXXY
public void setNSplitter(int nCount) 2p;I<C:Eo
{ Owu?ND
nSplitter = nCount; VO {z)_
} oGI'a:iff
} z^tzP~nI
T*#M'H7LSQ
0nD?X+u
/* >\:GFD{z
**Utility.java xq,ql@7
*/ rA?<\*
package NetFox; ]v>[r?X#V
Dbi ^%
7R79[:uwJ
public class Utility { `'XN2-M8
v%2Dz
j-**\.4a~
public Utility() 3ww\Z8UeK
{ 73'AQ")UJ
e>c -b^{&
McS]aJfrk
} ZD|F"v.
H$WD7/?j
//线程睡眠 0n2H7}Uq
public static void sleep(int nSecond) Gukvd6-g9b
{ Srmr`[i
try{ ',]Aj!q
Thread.sleep(nSecond); L'KKU4zj
} Qt>kythi
catch(Exception e) jwLZC
{ d(RMD
e.printStackTrace (); f2o6GC_
} Y7qQ`|
} lo6upirZX
DQ/rx`BG
//日志 x_<#28H!
public static void log(String sMsg) C<9GdN
{ +p jB/#4
System.err.println(sMsg); PbS1`8|4
} *3={s"a.(
v_U/0 0
&XI9%h9|
public static void log(int sMsg) c1FSQ m81
{ \zk>cQ
System.err.println(sMsg); F{Yr8(UHA
} 9-_Lc<
} q&?hwX Z7
VCnf`wZB"
Zon7G6s9`
/* <zTz/Hk`
**TestMethod.java =a=:+q g
*/ qj:[NPwaM
package NetFox; keD?#yY
z ULHgG
PcZ<JJ16F$
public class TestMethod { |unvDXx-
,/V~T<FI
pnx^a}|px
public TestMethod() adri02C/
{ ///xx/weblogic60b2_win.exe H<ovIMd
try{ c'VCCXe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $>_`.*I/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uy|!f]"?
SiteFileFetch fileFetch = new SiteFileFetch(bean); $'d,X@}8
fileFetch.start(); yk4py0xVl
} ac@\\2srV
catch(Exception e){e.printStackTrace ();} )Kl@dj
.L1[Rv3
KI*bWe
} T1Z*>(M
) d'H&c3
daSx^/$R
public static void main(String[] args) u^]Gc p
{ W]bytsl
new TestMethod(); AEWrrE
} Z]2z*XD
} nB :iG
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