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)); S]?I7_
} R|[gEavFl
for(int i=0;i<nEndPos.length-1;i++) YL/B7^fd8
{ AbIYdFXB
nEndPos = nStartPos[i+1]; w d6+,B
} byPqPSY
nEndPos[nEndPos.length-1] = nFileLength; 814cCrr,o
} "EnxVV
} XA\wZV |{
oj[<{/,C9
lsU`~3nr
//启动子线程 Z6#(83G4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \lF-]vz*
for(int i=0;i<nStartPos.length;i++) \f'=
{ @b{$s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0E#?H0<OeG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,Bl_6ZaL
nStartPos,nEndPos,i); MP~+@0cv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nnCz!:9p
fileSplitterFetch.start(); QObHW[:F
} W4=A.2[q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =m6<H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c]NZGn*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nZ[`Yrq)0
nEndPos = " + nFileLength); ?N&s.
// fileSplitterFetch[nPos.length-1].start(); |}Z2YDwO/
d?aZk-|c
F!P,%JmI<
//等待子线程结束 =nv/ r
//int count = 0; r |2{(+
//是否结束while循环 Gm=e;X;r
boolean breakWhile = false; T}Wse{
(?ZS9&y}
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while(!bStop) A}i>ys
{ ,3Nna:~f
write_nPos(); '?T<o
Utility.sleep(500); WTu!/J<\
breakWhile = true; gSkY c{b
V5p->X2#
oE)xL%*
for(int i=0;i<nStartPos.length;i++) gUme({h&|
{ )\J~KB4
if(!fileSplitterFetch.bDownOver) $?uLFD
{ Xt!wOW
breakWhile = false; Nt687
break; b1yS1i D
} l0eh}d
} -_bDbYL
if(breakWhile) ow;a7
break; iyr<qtwK
r`e6B!p
omI"xx
//count++; 'rrnTd c
//if(count>4) 5>h/LE]"
// siteStop(); ps33&
} 9Dd`x7$a
@/xdWN!,
ld#YXJ;P.k
System.err.println("文件下载结束！"); cCcJOhk|d
} S$/SFB$)~W
catch(Exception e){e.printStackTrace ();} bjq.nn<=
} dRUmC H
n(_wt##wE~
rdH^"(
//获得文件长度 N!<X%Ym
public long getFileSize() @]L$eOV_
{ /sSM<r]5j
int nFileLength = -1; n!U1cB{
try{ B/B`=%~5_^
URL url = new URL(siteInfoBean.getSSiteURL()); % -.V6}V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F(w<YU%6
httpConnection.setRequestProperty("User-Agent","NetFox"); uM9Gj@_
6iY(RYZ7-
7wHd*{^9N
int responseCode=httpConnection.getResponseCode(); 1";s#Jq
if(responseCode>=400) ]'Gz~Z%>F
{ uCgJF@
processErrorCode(responseCode); U-D00l7C
return -2; //-2 represent access is error {ITxHt
} DIgur}q)@
~|ha91
sHQO*[[
String sHeader; q-S#[I+g
VRg y
&Y3ZGRT
for(int i=1;;i++) XE#$|Z
{ ;8b!T -K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P.djR)YI
//Utility.log(in.readLine()); $)6x3&]P
sHeader=httpConnection.getHeaderFieldKey(i); gCbS$Pw
if(sHeader!=null) M]xfH*
{ =+H,}
if(sHeader.equals("Content-Length")) "O_)~u
{ hb1eEn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b`;Cm)@X!)
break; eKRE1DK
} m14'u GC
} 5+t$4N+P
else h r6?9RJY
break; 3il$V78|
} z~ua#(z1S
} &,* ILz
catch(IOException e){e.printStackTrace ();} <KX+j,4
catch(Exception e){e.printStackTrace ();} wGWv<<Qw"
hRqr
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Utility.log(nFileLength); 7v}(R:*
|Z8Eu0RSb
^b 3nEcQn
return nFileLength; "d2JNFIHb
} ER;\Aes*?
vVSf'w
{:=]J4]
//保存下载信息（文件指针位置） SeLFubs_
private void write_nPos() o3:BH@@
{ U#{(*)qr
try{ ?U =Mdw
output = new DataOutputStream(new FileOutputStream(tmpFile)); }|wC7*^)
output.writeInt(nStartPos.length); )"_&CYnd
for(int i=0;i<nStartPos.length;i++) a3,A_M}M'
{ IA$=
// output.writeLong(nPos); @?gRWH;Pq
output.writeLong(fileSplitterFetch.nStartPos); 3E}j*lo
output.writeLong(fileSplitterFetch.nEndPos); 7/iN`3Bz
} Z6&bUZF$bE
output.close(); z'\BZ5riX<
} COj^pdE3
catch(IOException e){e.printStackTrace ();} =h.` ey
catch(Exception e){e.printStackTrace ();} uH#X:Vne
} G/_xn5XDD
m= %KaRI
;D@F
//读取保存的下载信息（文件指针位置） L1&` 3a?pL
private void read_nPos() {U4{v=,!I
{ P G zwS
try{ #}Bv/`t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )(pgJLW
int nCount = input.readInt(); T "#DhEM
nStartPos = new long[nCount]; k#Qjm9V
nEndPos = new long[nCount]; M~)iiKw~MY
for(int i=0;i<nStartPos.length;i++) 7/K'nA
{ \\C!{}+
nStartPos = input.readLong(); Jgy6!qUn_
nEndPos = input.readLong(); XANJA
} L@J$kqWY
input.close(); V7vojm4O
} 'a$/!~X
catch(IOException e){e.printStackTrace ();} ygd*zy9
catch(Exception e){e.printStackTrace ();} Q8_5g$X\
} w^:@g~
%VE FruM
fc4jbPp:M
private void processErrorCode(int nErrorCode) ,+x\NY2d
{ HUbXJsSP
System.err.println("Error Code : " + nErrorCode); G0Z$p6z
} G]dHYxG
21] K7
q?8#D
//停止文件下载 hTPvt
public void siteStop() :u2tu60&MJ
{ oWggh3eXk
bStop = true; \aN5:Yy
for(int i=0;i<nStartPos.length;i++) )iZhE"?z
fileSplitterFetch.splitterStop(); SN`L@/I
I/gfsyfA
U^-RyE!}
} cca]@Ox]
} slLTZ]
//负责部分文件的抓取 swMR+F#u*
**FileSplitterFetch.java bNoZ{ 7
*/ |=W>4>
package NetFox; X.rbJyKe
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McN'J.Sxp
import java.io.*; ]ed7Q3lq
import java.net.*; R5 EC/@
Z7Nhb{
7e{w,.ny!
public class FileSplitterFetch extends Thread { o+\?E.%%g
5^Lbc.h
fQw|SW
String sURL; //File URL Iapzhy2l
long nStartPos; //File Snippet Start Position 2O2d*Ld>
long nEndPos; //File Snippet End Position ^(:na6C
int nThreadID; //Thread's ID o/!a7>xO4
boolean bDownOver = false; //Downing is over N9z!-y'X
boolean bStop = false; //Stop identical 0IsnG?"
FileAccessI fileAccessI = null; //File Access interface z7a@'+'
8 ;=?Lw?
5jTA6s9zA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *C> N
{ @!(V0-
this.sURL = sURL; lPz5.(5'
this.nStartPos = nStart; ; d}
this.nEndPos = nEnd; n>%TIoY
nThreadID = id; ;kVo? W]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *yW9-(
} =gSACDTc
eh3CVgH91;
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public void run() ?\a';@h
{ IZ]L.0,
while(nStartPos < nEndPos && !bStop) TJs@V>,
{ fy!,cK};
1:"ZS ]i
=}W)%Hldr.
try{ ,E4qxZC(X
URL url = new URL(sURL); 3[To"You
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yn{U/+
httpConnection.setRequestProperty("User-Agent","NetFox"); P"c7h7
String sProperty = "bytes="+nStartPos+"-"; m RtE~~p
httpConnection.setRequestProperty("RANGE",sProperty); YFW0
Utility.log(sProperty); 6r)qM)97
Rs 0Gqx
jt",\%j
InputStream input = httpConnection.getInputStream(); nZUBblRJ)
//logResponseHead(httpConnection); U,$^|Iz
;p)fW/<
_NM=9cWd
byte[] b = new byte[1024]; QBT_H"[
int nRead; 7ZgFCK,8m,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fehM{)x2:
{ qd?k#Gw&
nStartPos += fileAccessI.write(b,0,nRead); YCB=RT]&`
//if(nThreadID == 1) skfFj&_T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l@%7] 0!T
} *:V"C\`^n
^VB_>|UN4
ehls:)F
Utility.log("Thread " + nThreadID + " is over!"); Z9 tjo1X
bDownOver = true; )`]} D[j
//nPos = fileAccessI.write (b,0,nRead); JxLD}$I
} p\7(IhW@
catch(Exception e){e.printStackTrace ();} 1)wzSEV@
} uEkUK|
} gj Ue{cb5
tr\}lfK%
q9c:,k
//打印回应的头信息 g4*]R>f
public void logResponseHead(HttpURLConnection con) l]o&D))R
{ DcQsdeuQ
for(int i=1;;i++) O WVa&8O
{ |^E#cI
String header=con.getHeaderFieldKey(i); 8z,|N#
if(header!=null) NbnuQPb'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nr<&j#!L
Utility.log(header+" : "+con.getHeaderField(header)); 38T2IN
else E6d0YgfD
break; rz%=qY
} nzHsyL
} we&g9j'
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&Rx-zp&dJ
public void splitterStop() 0UvN ws
{ ye)CfP=ID\
bStop = true; M[R\URu8
} Ue<Y ~A
')/yBH9mR
qwU,D6
} V{[vIt*
VL/%D*
~cSOni`
/* 9+\3E4K
**FileAccess.java S5Q$dAL
*//文件访问(定位，写) RvF6bIqo
package NetFox; ^\uj&K6l
import java.io.*; iS^IqS
q|. X[~e|
%K_[Bx{B
public class FileAccessI implements Serializable{ Ncu\;K\N
bb6J$NR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r~uWr'}a}
RandomAccessFile oSavedFile; X#mppMU
long nPos; $!<J_d*
~)#JwY
sSC yjS'T
public FileAccessI() throws IOException x62b=k}
{ k4+F
this("",0); Brh<6Btl
} vb-L "S?kC
R)"Y40nW
a(Bo.T<2@
public FileAccessI(String sName,long nPos) throws IOException 9i8D_[
{ cZN+D D
oSavedFile = new RandomAccessFile(sName,"rw"); QUp()B1
this.nPos = nPos; dIG(7~
oSavedFile.seek(nPos); Z_Ox'
} gd6We)&
+%G*)8N3
K4i#:7r'b
public synchronized int write(byte[] b,int nStart,int nLen) k, )7v
{ EnJAHgRV;e
int n = -1; ;SF0}51
try{ "PBUyh-Z
oSavedFile.write(b,nStart,nLen); 6|m1z
n = nLen; ip4:px-
} b<qv /t)$
catch(IOException e) ur-&- G^
{ tnz BNW8
e.printStackTrace (); Pq~"`-h7:
} l tr=_
h3D8eR.
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return n; W$@q ~/E
} '+NmHu:q
W{l+_a{/9
2As 4}
} EN()dCQHr
p%CAicn
3uCC_Am
/* Zgo^M,g
**SiteInfoBean.java ="RDcf/
*/ b&A+`d
package NetFox; u4NMJnX
Aj.TX%}`h
Nhn5 iN1*
public class SiteInfoBean { FGBPhH% (8
:k075Zr/#D
=M)>w4-
private String sSiteURL; //Site's URL JQ'NFl9<
private String sFilePath; //Saved File's Path T{bM/?g
private String sFileName; //Saved File's Name x`w 4LF
private int nSplitter; //Count of Splited Downloading File e~c;wP~cO
Mi9A%ZmP
;14[)t$
public SiteInfoBean() XRKL;|cd
{//nSplitter的缺省值为5 ~" B0P>7
//default value of nSplitter is 5 ~d ~$fR
this("","","",5); gQgG_&xkC
} KP[ax2!x
"8J$7g@n@
:#"gQ^YNp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \y{Bnp5h
{ V#^~JJW^
sSiteURL= sURL; tQbDP!,A*=
sFilePath = sPath; =-~82%
sFileName = sName; :S0r)CNP
this.nSplitter = nSpiltter; bgqN&J)Jr)
3Tg
G6_Kid}"q
} y'xB? >|
K5z*DYT
g4&zBn
public String getSSiteURL() c~b[_J)
{ K& <|94_k
return sSiteURL; >5#`j+8=q
} wy<m&M<Gr
EE#4,d`J
SJ^.#^)
public void setSSiteURL(String value) 69ia #
{ W*e6F?G
sSiteURL = value; j?29_Az
} pvQw+jX
;&37mO/T
l|^p;z:d
public String getSFilePath() NZ/gp"D?
{ `QXO+'j4
return sFilePath; }H!c9Y
} [MdVgJ9'
GN?^7kI
O9oYuC:q
public void setSFilePath(String value) ! pR&&uG
{ Uc>kCBCd
sFilePath = value; Mi,yg=V
} 6A;V[3
}L>}_NV\
'}e_8FS
public String getSFileName() [0El z@.C
{ "yXKu)_
return sFileName; TDs=VTd@Z
} \Pi\c~)Pr
qxf!]jm
B BbGq8p
public void setSFileName(String value) rS\j9@=Y4
{ X#'DS&{
sFileName = value; 8{#WF#
} P{i\x#
q,F\8M\$
ST5L O#5
public int getNSplitter() !?Gt5$f
{ D+P(
return nSplitter; BCYTlxC'
} H=9kDP${
8om6wALXB
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public void setNSplitter(int nCount) dKTyh:_{
{ K'%2'd
nSplitter = nCount; 7DDd1"jE
} 2-728
} T$%r?p(s
kd)Q$RA(
3)88B"E
/* %V71W3>6WS
**Utility.java c.dk4v%Y5
*/ v/*}M&vo
package NetFox; CuC1s>
rR]U Ff
cWjb149@)
public class Utility { 3.@"GS#"[
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7'Z-VO
public Utility() H xs'VK*
{ 9uR+
\ne1Xu:hM
uP, iGA
} vZ,DJ//U,
(StX1g'
//线程睡眠 %]7'2
public static void sleep(int nSecond) K+MSjQS"
{ 'yxN1JF
try{ &H8wYs
Thread.sleep(nSecond); jq%%|J.x
} oC ?UGY~xL
catch(Exception e) pHQrjEF*
{ fwQVxJe
e.printStackTrace (); ypU-/}Cf,
} -yOwX2Wv5;
} hr$Wt?B
J^<Gi/:*^
//日志 G0#<SJ,)
public static void log(String sMsg) ]%M&pc3U
{ JLd-{}A""-
System.err.println(sMsg); fi%)520
} GuK3EM*_
!/nXEjW?
m`i_O0T
public static void log(int sMsg) r{>Q{$Q
{ $UNC0(4
System.err.println(sMsg); yFoPCA86y
} l266ufO.u-
} Ft E5H
Pi+pQFz5
Tp46K\}Uf
/* Gj_7wP$
**TestMethod.java I(<9e"1O
*/ j,n\`7dD$
package NetFox; >``sM=Wat
d1P|v( `S9
Qb%o%z?hee
public class TestMethod { (+yH
K;z$~;F
_(zZrUHB
public TestMethod() YMN=1Zuj?
{ ///xx/weblogic60b2_win.exe SzP`(}AU
try{ @E 8P>kq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hf/ZaBn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BLN|QaZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); xKR\w!+Z'
fileFetch.start(); +7\d78U
} eFh7#~m
catch(Exception e){e.printStackTrace ();} 7s0\`eXo/
l+#J oc<8
qk~m\U8r
} "1YwV~M5
#x qiGK
aFaioE#h(
public static void main(String[] args) }?\^^v h7
{ {E; bT|3z
new TestMethod(); hK,a8%KnFA
} FsO_|r
} Fc#Sn2p*
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