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)); Q]9H9?}N?
} Ymkk"y.w
for(int i=0;i<nEndPos.length-1;i++) 5<\&7P3y
{ hG .>>
nEndPos = nStartPos[i+1]; xjB2?:/2
} _doX&*9u
nEndPos[nEndPos.length-1] = nFileLength; dIgaw;Ch]
} Vui5ZK
} teH $hd-q
6Ko[[?Lf[
E5qh]z(
//启动子线程 % \p:S)R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]CsF} wr'z
for(int i=0;i<nStartPos.length;i++) b3N>RPsHS
{ =Bo(*%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cy-q9uTm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g N76
nStartPos,nEndPos,i); Jy?s'tc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w|!>>W6J
fileSplitterFetch.start(); )_N|r$i\
} 0j\?zt?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $o"Szy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #D~atgR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >Vz Gx(7q
nEndPos = " + nFileLength); (~}IoQp>
// fileSplitterFetch[nPos.length-1].start(); >U.TkB
|3`Sd;^;
)/kkvI()l
//等待子线程结束 F!OVx<
//int count = 0; S'm&Ll2i@
//是否结束while循环 <cm,U)j2
boolean breakWhile = false; a]XQM$T$
c+chwU0W
Y^$^B,
while(!bStop) -jy-KC
{ .^j6
write_nPos(); m-9{@kgAM?
Utility.sleep(500); EEFM1asJf
breakWhile = true; qXPjxTg{[
(]7&][
yk OJhd3
for(int i=0;i<nStartPos.length;i++) Lsv[@Rl
{ ]Tk3@jw+b
if(!fileSplitterFetch.bDownOver) ?n<b:oO
{ I:l<t*
breakWhile = false; 2Pn
break; Z ?`
} 9SF2
} yx?Z&9z <
if(breakWhile) Lh.?G#EM
break; 7.)e4
A.tONPi
Y-\/Y*;cd
//count++; B@g 0QgA
//if(count>4) 0Y[LzLn
// siteStop(); WBT/;),}:
} R{Q*"sf
1Q1NircJ
,>%2`Z)
System.err.println("文件下载结束！"); 1FCqkwq[
} mOji\qia
catch(Exception e){e.printStackTrace ();} 6vp\~J
} 'F>eieO
"]h4L
ParOWs~W/
//获得文件长度 6)63Yp(
public long getFileSize() Ojqbj0E9
{ *y +T(73
int nFileLength = -1; 6\>S%S2:
try{ P__JN\{9
URL url = new URL(siteInfoBean.getSSiteURL()); [iVCorU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iq'hel
httpConnection.setRequestProperty("User-Agent","NetFox"); pleLdGq
xL8r'gV@
6UK{0\0
int responseCode=httpConnection.getResponseCode(); xG:eS:iT
if(responseCode>=400) l_bvwo
{ ~/Gx~P]
processErrorCode(responseCode); =kvfe" N0e
return -2; //-2 represent access is error eF+:w:\h
} g-`HKoKe
lnuf_;0
bH4'j/3
String sHeader; QHOA__?
9qc<m'MZ
8xs}neDg*
for(int i=1;;i++) _GEt:=DAP#
{ (T;4'c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?/ xk
//Utility.log(in.readLine()); +>3XJlZV
sHeader=httpConnection.getHeaderFieldKey(i); |iN!V3#S
if(sHeader!=null) k"_i7
{ :lj1[q:Y>
if(sHeader.equals("Content-Length")) '<! b}1w0
{ IvuKpX>*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ny# ?^.1
break; } IJ
} 9))E\U
} ?d@3y<A,~
else #ra"(/)
break; (gN[<QL
} *J^l r"%c
} 7|4t;F!
catch(IOException e){e.printStackTrace ();} ]7<}EG
catch(Exception e){e.printStackTrace ();} e8T#ZWr*
XaT9`L<
)~/;Xl#b-
Utility.log(nFileLength); n8W+q~sW%
N-XOPwx'
~)>O=nR
return nFileLength; #oBMA
} GIXxOea1
1k-YeQNe
TZ#(G
//保存下载信息（文件指针位置） <T]BSQk
private void write_nPos() Yq~$Q4
{ j8Nl'"
try{ nnr g^F
output = new DataOutputStream(new FileOutputStream(tmpFile)); `/]Th&(5
output.writeInt(nStartPos.length); Ky"]L~8$
for(int i=0;i<nStartPos.length;i++) * V;L|c
{ oU/CXz?H
// output.writeLong(nPos); Vl=!^T}l+
output.writeLong(fileSplitterFetch.nStartPos); b4NUx)%ln
output.writeLong(fileSplitterFetch.nEndPos); b(^gv
} "^sh:{
output.close(); zxN,ys
} <dzfD;
catch(IOException e){e.printStackTrace ();} CeL`T:]r
catch(Exception e){e.printStackTrace ();} tBR"sBiws
} V>"nAh]}.
;. jnRPo";
80qSPitj
//读取保存的下载信息（文件指针位置） yX%q7ex
private void read_nPos() >q W_%
{ c6 O1Z\M@\
try{ dnRS$$9#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2R}9wDP
int nCount = input.readInt(); `re9-HM
nStartPos = new long[nCount]; *Uq1q
nEndPos = new long[nCount]; &T7|f!y
for(int i=0;i<nStartPos.length;i++) =Xwr*FTr
{ DH7B4P
nStartPos = input.readLong(); "S8JHHx
nEndPos = input.readLong(); k^A17Nf`2
} 6T3uv,2
input.close(); gz{~\0y
} | %E\?-TK
catch(IOException e){e.printStackTrace ();} }M3f ?Jv
catch(Exception e){e.printStackTrace ();} .MNi)+
} S"t6 *fWr
,&+"|,m
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private void processErrorCode(int nErrorCode) Ql~9a [8T~
{ oW0A8_|9
System.err.println("Error Code : " + nErrorCode); |>w>}w`~
} :exgdm;N
sZ~q|}D-
LW+a-i
//停止文件下载 RM^3Snd=V
public void siteStop() H{XbKLU
{ E0F8FR'
bStop = true; P''5A6#5
for(int i=0;i<nStartPos.length;i++) :.;pRz
fileSplitterFetch.splitterStop(); 4J#F;#iA
+y%"[6c|
<d2?A}<
} CcF$?07 i
} ;rBd_
//负责部分文件的抓取 ].E89_|O
**FileSplitterFetch.java jZRf{
*/ FG-v71!h#
package NetFox; q_0So}
I``S%`h
YH_mWN\Wu
import java.io.*; w$ zX.;s
import java.net.*; \0}!qG![AA
kNC.^8ryz[
{VBn@^'s
public class FileSplitterFetch extends Thread { $-HP5Kj(k-
F0yvV6;
jO` b&]0
String sURL; //File URL ;3 N0)
long nStartPos; //File Snippet Start Position 5m.{ayE
long nEndPos; //File Snippet End Position [73 \jT
int nThreadID; //Thread's ID ,r$k79TI
boolean bDownOver = false; //Downing is over hxwo<wEg
boolean bStop = false; //Stop identical KKrLF?rc
FileAccessI fileAccessI = null; //File Access interface 2(SU# /,
B=EI&+F+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rV yw1D
{ uL\b*rI
this.sURL = sURL; QNH-b9u>8
this.nStartPos = nStart; 2kP0//
this.nEndPos = nEnd; & XS2q0-x
nThreadID = id; }6Ut7J]a|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =H<I` J'
} |E%i t?3M
x,U'!F
0_!')+
public void run() 2sezZeMV
{ tHhau.!
while(nStartPos < nEndPos && !bStop) s} I8:ufT
{ W0zRV9"P
pUGFQ."\
W6e,S[J^FY
try{ i~};5j(
URL url = new URL(sURL); ]lX`[HX7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xz$-_NWW
httpConnection.setRequestProperty("User-Agent","NetFox"); C:*=tD1
String sProperty = "bytes="+nStartPos+"-"; %anY'GK
httpConnection.setRequestProperty("RANGE",sProperty); fU6O:-
Utility.log(sProperty); {Xw6]d
3MmpB9l#H
(D\7EH\9,]
InputStream input = httpConnection.getInputStream(); q=EHB5!q
//logResponseHead(httpConnection); >yZe1CP
1*x;jO>Hk
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byte[] b = new byte[1024]; ~wtK(U
int nRead; Z[ NO`!<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q)/V>QW
{ P{bRRn4Z
nStartPos += fileAccessI.write(b,0,nRead); #Nv^F
//if(nThreadID == 1) 8vp*U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EZ"n3#/
} qG6?k}\\
tj'xjX
*]7$/%.D
Utility.log("Thread " + nThreadID + " is over!"); ~nVO%IxM4J
bDownOver = true; B~CdY}UTsj
//nPos = fileAccessI.write (b,0,nRead); rexNsKRK_
} &H4Y`xV^=
catch(Exception e){e.printStackTrace ();} #JAy
} /e:kBjysJ
} <Jf[N=
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f@j)t%mh
//打印回应的头信息 up@I,9C/
public void logResponseHead(HttpURLConnection con) O x),jc[/
{ JK/gq}c
for(int i=1;;i++) {!L25
{ NT0im%
String header=con.getHeaderFieldKey(i); LmZ"_
if(header!=null) $(r/N"6)O2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]aMeMhe-
Utility.log(header+" : "+con.getHeaderField(header)); lz [s
else {@&%Bq*&
break; A<U9$"j9J
} .N>Th/K8
} E*Z# fa
}T~}W8H
[S_qi,
public void splitterStop() S]x\Asj;w
{ `3e>JIl"0
bStop = true; !qe:M]C'l
} ]zATdfa
V{{Xz:
Bnfp_SM
} YApm)O={
TF%MO\!
;{Nc9d
/* |[W7&@hF
**FileAccess.java ccY! OSae
*//文件访问(定位，写) :Ldx^UO
package NetFox; 0@tN3u?dx
import java.io.*; v;o/M6GL5
(3Dz'X
J3z:U&%=
public class FileAccessI implements Serializable{ \0fk^
_'0C70
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i}gsxq%
RandomAccessFile oSavedFile; [vTk*#Cl4
long nPos; )Y &RMYy
g2%fla7r
EM7Z g 65
public FileAccessI() throws IOException ?p'DgL{
{ $1uT`>%
this("",0); ]99@Lf[^f
} mlO\wn-F
^N&@7s
F#)@ c
public FileAccessI(String sName,long nPos) throws IOException f;=<$Y>i
{ <lgX=wx L
oSavedFile = new RandomAccessFile(sName,"rw"); 1d 1 ~`B
this.nPos = nPos; awl3|k/
oSavedFile.seek(nPos); Bp-e< :
} a7}O.NDf
dCA! R"HD
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public synchronized int write(byte[] b,int nStart,int nLen) *t300`x
{ (>SucUU
int n = -1; _P9*78
try{ 7d^ ~.F
oSavedFile.write(b,nStart,nLen); 2QgD<
n = nLen; >0JCu^9
} "i,ZG$S#E
catch(IOException e) lkW5<s_
{ tu's]3RE
e.printStackTrace (); DJb9] ,=a
} j@R"AP}
s+E: 7T9P
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return n; 8RT<?I^5
} [P`<y#J3F
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} V8rS~'{\
&Qmb?{S0
q1Ad"rm
/* 2(f-0or(
**SiteInfoBean.java / 5/mx
*/ [)?yH3
package NetFox; ft1V1 c
aVZ/e^kk-
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public class SiteInfoBean { ji C2B
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48Jt1^
private String sSiteURL; //Site's URL =fJ /6
private String sFilePath; //Saved File's Path &$ fyY:<\
private String sFileName; //Saved File's Name WWTRB +1>
private int nSplitter; //Count of Splited Downloading File z.^_;Vql_
Fj46~#ZZ
1\J9QZX0
public SiteInfoBean() |rI;OvZ\
{//nSplitter的缺省值为5 29zMs9oKPP
//default value of nSplitter is 5 [#(',~lN7
this("","","",5); ux~=}{tz
} tn;{r
2BiFP||
P(!%Pp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Uy|Tu~
{ ;Sfe.ky@6
sSiteURL= sURL; OC)=KV@KE
sFilePath = sPath; sR^b_/ElxT
sFileName = sName; h.wffk,
this.nSplitter = nSpiltter; g_JQW(_
jOd+LXPJ
v\E6N2.S
} J50n E~
4 !m'9
_St":9'uU
public String getSSiteURL() Q5A,9ovNZ
{ [930=rF*
return sSiteURL; KWM.e1(
} U'u_'5{
$)~:H-
SYh>FF"
public void setSSiteURL(String value) uzT+,
{ %`~+^{Wp
sSiteURL = value; BLAF{vVaf
} K{,'%|
z]KJ4
\4>w17qng
public String getSFilePath() YkE_7r(1
{ x!7r7|iV
return sFilePath; L2_[M'
} u8t|!pMF8
|!/+T^u
s}-j.jzB{
public void setSFilePath(String value) C/QrkTi=
{ (P=WKZMPN
sFilePath = value; `,]_r4~ ~
} ]')y(_{
+XSe;xk;rD
;Qi!~VsP;
public String getSFileName() p1hF.
{ =qbN?a/?2
return sFileName; VFMn"bYOB
} 'p78^4'PL
)Gk?x$pY@
T1R~^x1
public void setSFileName(String value) ~]].i~EV(
{ _CTg")0o
sFileName = value; ng~LCffpY
} q/Vl>t
^)GaVL^"5
on"ENT
public int getNSplitter() aOd|;Z
{ KJv%t_4'F
return nSplitter; !@wUARQ
} {$5g29
Ux{0)"fj
3)L#V .
public void setNSplitter(int nCount) =CD.pw)B1
{ rqnxRq
nSplitter = nCount; +v'2s@e` #
} TvS<;0~K
} 4[&&E7]EX
N8k=c3|
XR3 dG:
/* d[5v A/8O
**Utility.java /9,'.
*/ .'$8Hj;@
package NetFox; '9zKaL
dG8mE&$g
c5uC?b].
public class Utility { 6k![v@2R
xB[W8gQ6fa
5`$!s17
public Utility() XA(.O|VZ
{ (:o:_U
b|@zjh;]A7
"FhC"}N
} *DXX*9 0
GN Ewq$
//线程睡眠 ~-y&C%
public static void sleep(int nSecond) {0np
{ |(2#KMEWa
try{ b:r8r}49
Thread.sleep(nSecond); _cC1u7U9
} 10.ZBfn
catch(Exception e) rNKeY48\
{ _~{J."q
e.printStackTrace (); P;-.\VRu
} 2VUN
} r%WHYhD
Oo-4WqRJ
//日志 m/jyc# L:u
public static void log(String sMsg) %'=2Jy6h
{ "KS"[i!3j
System.err.println(sMsg); 7'65+c[&
} gmn b
evD=]iVD
!syyOfu`}
public static void log(int sMsg) fAz4>_4
{ NFtA2EMLu[
System.err.println(sMsg); |(TEG.<g
} Y2'HP)tfIw
} rBU)@IpDG
.qKfhHJ
o8H\l\(
/* 98| v.d
**TestMethod.java FGie*t
*/ >R_m@$`
package NetFox; \ykA7Y%
{T,}]oX
US^%pd
public class TestMethod { $T:;KcW)
<P ?gP1_zi
2xiE#l-V2
public TestMethod() B2*>7 kc_s
{ ///xx/weblogic60b2_win.exe n@R/zy
try{ lZe-A/E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s-(c-E09
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9z{g3m70@
SiteFileFetch fileFetch = new SiteFileFetch(bean); tS5J{j>T
fileFetch.start(); #G?#ot2o
} f*88k='\W
catch(Exception e){e.printStackTrace ();} y29G#Y4J
Q9h=1G\K
5} <OB-9
} E(_k#X
Rq e|7/As
ZZwIB3sNhf
public static void main(String[] args) zBwqIJfM
{ u|.|dv'mbp
new TestMethod(); P*>?/I`G
} lj8ficANo
} $cuBd
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