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)); k&hc m
} AgF5-tz6x
for(int i=0;i<nEndPos.length-1;i++) +)nT|w45
{ !\[+99F#
nEndPos = nStartPos[i+1]; ~`Qko-a&
} M^rM-{?<
nEndPos[nEndPos.length-1] = nFileLength; _nT{g
} 3-40'$lE
} Y^"4?96
m8+(%>+7
*5%*|>
//启动子线程 D}Ilyk_uUw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [-*F"}D,
for(int i=0;i<nStartPos.length;i++) ~#:e*:ro
{ lhC6S'vq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jn9 ShF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~c{:DM
nStartPos,nEndPos,i); cd;NpN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h$C@j~
fileSplitterFetch.start(); DJh&#b
} u"$a>S_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0BkV/v1Uc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r0m)j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5CJZw3q
nEndPos = " + nFileLength); vd#,DU=p!
// fileSplitterFetch[nPos.length-1].start(); 2>S~I"o0
-'rj&x{Q)U
")s!L"x
//等待子线程结束 Q"a2.9Eo
//int count = 0; |c-LSs'\
//是否结束while循环 Oi:JiD=
boolean breakWhile = false; -7'#2P<)
9CUimZ
IN^9uL]B
while(!bStop) 4lc)&
{ *2u E
write_nPos(); fUag1d
Utility.sleep(500); rlok%Rt4Z
breakWhile = true; QF-)^`N
.BTx&AqU
7x.%hRk
for(int i=0;i<nStartPos.length;i++) pt:;9hA
{ !^U6Z@&/R
if(!fileSplitterFetch.bDownOver) {j(4m
{ >3;^l/2c
breakWhile = false; ](r ^.k,R
break; 2xmk,&s
} (0*v*kYdL+
} nYv#4*
if(breakWhile) ]>:^d%n,}
break; ;np_%?is
i%(yk#=V
`rWB`q|i<
//count++; (b/d0HCND
//if(count>4) MM#cLw
// siteStop(); &jts:^N>
} #dJ 2Q_2
PNF4>)
AvRcS]@=
System.err.println("文件下载结束！"); Wb=Jj 9;
} z<C[nR$N
catch(Exception e){e.printStackTrace ();} 9rj('F&1
} &R]pw`mTH
f[/.I,9U^
hd^x}iK"
//获得文件长度 G_oX5:J*
public long getFileSize() 0*(K DDv
{ GXb47_b^
int nFileLength = -1; +}!DP~y+
try{ }X1.Wt=?
URL url = new URL(siteInfoBean.getSSiteURL()); 2o{@nN8%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %= u/3b:o
httpConnection.setRequestProperty("User-Agent","NetFox"); Rlg#z4m
j)D-BK&+
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int responseCode=httpConnection.getResponseCode(); uIP iM8(
if(responseCode>=400) =Q?f96T
{ ;bHfn-X
processErrorCode(responseCode); oXc/#{NC
return -2; //-2 represent access is error j8HOc(
} ?M&4pO&Y
OCx5/ 88X
~"mj;5Id
String sHeader; yuNfhK/#r
0M!0JJy#*
Fe="EDh
for(int i=1;;i++) ' Js?N
{ r=csi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CM 9P"-
//Utility.log(in.readLine()); i>Iee^_(
sHeader=httpConnection.getHeaderFieldKey(i); 7Jx%JgF
if(sHeader!=null) )*[ ""&
{ .)ST[G]WK
if(sHeader.equals("Content-Length")) O<`R~
{ F!CAitxd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dr'sIH^
break; atnQC
} ('WY5Yps
} ,+-?Zv 2
else k/#M<z
break; aW`dFitpM
} :o\5K2]:
} B T7Id
catch(IOException e){e.printStackTrace ();} +Jw{qQR/*
catch(Exception e){e.printStackTrace ();} i| xt f
aF])"9
6GOg_P
Utility.log(nFileLength); ;:_(7|
wW()Zy0)
t-lv|%+8
return nFileLength; :Y.e[@!1x
} vXubY@k2
1l]C5P}E
jaqV[*440U
//保存下载信息（文件指针位置） 6$z'wy/*
private void write_nPos() 4g!7 4a
{ {bTeAfbf]
try{ $I(}r3r
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;C_ >
output.writeInt(nStartPos.length); 1 ;Ju]
for(int i=0;i<nStartPos.length;i++) G;2[
{ ?>)yKa#U
// output.writeLong(nPos); /| f[us-w
output.writeLong(fileSplitterFetch.nStartPos); lM&UFEl-\
output.writeLong(fileSplitterFetch.nEndPos); ?waebuj>
} =, TSMV
output.close(); U?EG6t
} bFn(w:1Q
catch(IOException e){e.printStackTrace ();} PSEWL6=]N
catch(Exception e){e.printStackTrace ();} a>(~C'(<
} N?^_=KE@
U9F6d!:L7A
sS'{QIRC'
//读取保存的下载信息（文件指针位置） 'fl(N2t
private void read_nPos() RO$*G jQd
{ ! OfO:L7-
try{ paYz[Xq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Bt6xV<jD
int nCount = input.readInt(); vrO%XvXW
nStartPos = new long[nCount]; 0x4l5x$8
nEndPos = new long[nCount]; ~ a>S#S
for(int i=0;i<nStartPos.length;i++) +{0=<2(EC
{ Wbd_aR (
nStartPos = input.readLong(); Bn_g-WrT
nEndPos = input.readLong(); 9@etg4#]
} Cg*kN"8q
input.close(); H` Lu"EK
} 9/Wn!Ld
catch(IOException e){e.printStackTrace ();} >.@MR<H#5
catch(Exception e){e.printStackTrace ();} U2=hSzY
} %Y 2G
0/*X=5
`r9^:TMN
private void processErrorCode(int nErrorCode) CwB] )QV?
{ (ic@3:xR
System.err.println("Error Code : " + nErrorCode); EGEMZCdk2
} lux9o$ %
rxArTpS{.#
X_!$Pk7ma
//停止文件下载 _;VYFs
public void siteStop() U-ULQ|6U
{ |QMT A5
bStop = true; )=Y-f?o!
for(int i=0;i<nStartPos.length;i++) G "c/a8
fileSplitterFetch.splitterStop(); R{ 4u|A?9
(Otur
g!\QIv1D
} Pd,!&
} $4:~*IQ
//负责部分文件的抓取 R1~7F{FW
**FileSplitterFetch.java 0pCDEs
*/ m9k2h1
package NetFox; ,`+Bs&S8
$ JuLAqq
xNx`J@xt$
import java.io.*; ^[*AK_o_DQ
import java.net.*; W -3w7^
o=@ UXi
{YfYIt=.
public class FileSplitterFetch extends Thread { 2t.fD@
%K`4k.gN
w[|y0jtw
String sURL; //File URL }0krSzcn#,
long nStartPos; //File Snippet Start Position EtPgzw[#c9
long nEndPos; //File Snippet End Position r"6lLc
int nThreadID; //Thread's ID (s.o
boolean bDownOver = false; //Downing is over VJGwd`qo*A
boolean bStop = false; //Stop identical mxZ4 HD{
FileAccessI fileAccessI = null; //File Access interface }el,^~
&4[<F"W>47
z[%[bs2{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :> x:(K
{ EyzY2>"^
this.sURL = sURL; }&=uZ:
this.nStartPos = nStart; T<_+3kw
this.nEndPos = nEnd; &KLvr|
nThreadID = id; ;,R[]B01u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E=3#TBd
} :E}6S
&(GopWR`e
i^~sn `o
public void run() v)TUg0U=,
{ e-1;dX HL
while(nStartPos < nEndPos && !bStop) g+VRT,r
{ t% <pbZO
5BZ+b_A>VV
_8Pmv$
try{ yFIl^Ck%
URL url = new URL(sURL); PZ~`O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EC0zH#N
httpConnection.setRequestProperty("User-Agent","NetFox"); 5X#i65_-
String sProperty = "bytes="+nStartPos+"-"; 7ucx6J]c
httpConnection.setRequestProperty("RANGE",sProperty); g521Wdtnn
Utility.log(sProperty); 1fmSk$ y.9
.Ydr[
F%9e@{
InputStream input = httpConnection.getInputStream(); lrq>TJEcx
//logResponseHead(httpConnection); (q0No26;(
7O]J^H+7
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byte[] b = new byte[1024]; oA5<[&~<
int nRead; -wJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q|?`Gsr
{ 8|fLe\"
nStartPos += fileAccessI.write(b,0,nRead); {H/8#y4qp&
//if(nThreadID == 1) V}j%gy`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "tEj`eR
} jt0H5-x
pW`ntE#L
W` WLW8Qsw
Utility.log("Thread " + nThreadID + " is over!"); &E} I
bDownOver = true; `8.1&fBr
//nPos = fileAccessI.write (b,0,nRead); IY-(- a8
} F0X5dv
catch(Exception e){e.printStackTrace ();} "v*oga%
} Cij$GYkv
} >aNbp
B:B0p+$I
}x{rTEq
//打印回应的头信息 ]t8{)r
public void logResponseHead(HttpURLConnection con) JI28O8
{ {Q}!NkF1
for(int i=1;;i++) "FD<^
{ _Ac/ir[,:
String header=con.getHeaderFieldKey(i); Krt$=:m|1
if(header!=null) f>.`xC{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v)wY
Utility.log(header+" : "+con.getHeaderField(header)); &\CJg'D:m
else TsoCW]h
break; z_5rAlnwT.
} WV5r$
} ]Om'naD
ahK?]:&QO
,+swH;=7#r
public void splitterStop() |?4~T:
{ {o Q(<&Aw
bStop = true; Yg\{S<wr
} 5]A$P\7~1
fU\k?'x_
fzq'S]+
} ;$E~ZT4p
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* ePDc'
/* \<0G kp
**FileAccess.java PEOM1oY)w
*//文件访问(定位，写) (**-"o]HH
package NetFox; ::^qy^n
import java.io.*; <DA{\'jJ
w!=_
0R2S@4%Y
public class FileAccessI implements Serializable{ LS R_x$G+t
dXf]G6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AQJ|^'%
RandomAccessFile oSavedFile; )3D+gu
long nPos; &etL&s v
0xvMR&.H
Cy`<^_i
public FileAccessI() throws IOException F)[XIY&2/
{ F``EARG)iu
this("",0); %8rr*l5
} -52@%uB
2
0{^l2?mgSb
public FileAccessI(String sName,long nPos) throws IOException @'k,\$/
{ Q{ |+3!!'
oSavedFile = new RandomAccessFile(sName,"rw"); -$sl!%HO%
this.nPos = nPos; e{qp!N1!
oSavedFile.seek(nPos); +j)-L \
} 2fHIk57jP
!9ceCnwbNN
46Y7HTwE
public synchronized int write(byte[] b,int nStart,int nLen) 0{U]STj
{ df21t^0/
int n = -1; ~:ub
try{ *Dd(+NI
oSavedFile.write(b,nStart,nLen); ]*kP>
n = nLen; pUCEYR
} ^^t]vojX
catch(IOException e) 82^ z-t{
{ MIk #60Ab
e.printStackTrace (); |)|vG_
} ^6N3nkyZ
S+Yy
&kr_CP:;
return n; uJ)\P
} ^>vO5Ho.
h^[ppc{Z
$h|I7`
} 9:}RlL+cOk
F| ,Vw{
;ZE<6;#3IP
/* O;&yA<
**SiteInfoBean.java RpaA)R,
*/ $@ T6g
package NetFox; )+Y\NO?O
6a2w-}Fs
g#9*bF
public class SiteInfoBean { K\Y6 cj
rH}Dt@
@'NaA SB
private String sSiteURL; //Site's URL n'x`oI)-
private String sFilePath; //Saved File's Path XSHwE)m
private String sFileName; //Saved File's Name )P(d66yq'u
private int nSplitter; //Count of Splited Downloading File ]VHdE_7)
{8>_,z^P)
iBPdCp%]`
public SiteInfoBean() bCY^.S-
{//nSplitter的缺省值为5 q)z1</B-
//default value of nSplitter is 5 >m;|I/2@
this("","","",5); JUaKj@a|
} r,Y/4(.c7U
+^]PBMM1w
U(Hq4D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %;"B;~
{ b/D9P~cE
sSiteURL= sURL; 4<eJ
sFilePath = sPath; zYgK$u^H
sFileName = sName; 4o)\DB?!
this.nSplitter = nSpiltter; ?G%, k LJJ
]mJAKycE%
W&~iO
} u=ds]XP@
,uqbS
+=29y@c
public String getSSiteURL() 61eKGcjs:
{ [jtj~]&mO
return sSiteURL; g^<q L|
} ke;*uS
d= T9mj.@
s_Ge22BZ
public void setSSiteURL(String value) 1+PNy d
{ gp|7{}Q{
sSiteURL = value; 'k(~XA}X:
} }mT%N eS
aBA#\eV
GO:1 Z?^
public String getSFilePath() (1r>50Ge
{ ,[K)E
return sFilePath; n9-q5X^e>
} zf!\wY"`
GWkJ/EX
o4I!VK(C#s
public void setSFilePath(String value) fb=$<0Ocj
{ PB3!;
sFilePath = value; VkP:%-*#v
} Xm:gD6;9
?D$b%G{
s%TO(vT
public String getSFileName() @*`UOgP7
{ 5KPPZmO
return sFileName; ;(iUY/ h[h
} g9r5t';
W0?Y%Da(4m
51(`wo>LS
public void setSFileName(String value) d=5}^v#4
{ WUOPYYW<o
sFileName = value; $P}]|/Yb
} F*jjcUk
t%YX-@
/Geks/
public int getNSplitter() Qmc;s{-r;
{ .Mft+,"
return nSplitter; X=c ,`&^
} m=y,_Pz>U
z1KC$~{O
$^+KR]\q
public void setNSplitter(int nCount) z?) RF[
{ kKk |@
nSplitter = nCount; /dvnQW4}8
} &+r ;>
} `GN5QLg#}0
:>-sITeY
!m O] zn
/* \S@=zII_
**Utility.java Z$=$oJzB
*/ MUt^mu$86
package NetFox; eq 1 4
t:j07 ,1~
2,QApW_Y
public class Utility { kE(-vE9
QO`SnN}
D30Z9_^%:
public Utility() mM^8YL
{ LVcy.kU@]
ppo$&W &z
H=SMDj)s+
} mt6uW+t/
wTuRo J
//线程睡眠 #Uk6Fmu]
public static void sleep(int nSecond) .+~kJ0~Y
{ @_:?N(%(
try{ v&/-&(+
Thread.sleep(nSecond); J3}C T
} m_ONsZHy
catch(Exception e) jE5 9h
{ Fu$Gl$qV?%
e.printStackTrace (); O09g b[
} `[u>NEb
} !";$Zu
5N</Z6f'o
//日志 n)7$xYuH
public static void log(String sMsg) ]be2jQx3
{ \c^jaK5
System.err.println(sMsg); O NzdCgY
} (V%vFD1)
X!HSS/'
^>}[[:(6/
public static void log(int sMsg) 2X|jq4
{ .B-,GD}
System.err.println(sMsg); ;? QAPTz
} $,v+i -
} Z42Suy
r\- k/0
0lq4
/* }@0.
**TestMethod.java sEi.f(WA
*/ z{+;'9C
package NetFox; D7'0o`|
Y`p&*O
]Lft^,7
public class TestMethod { y/*Tvb #TJ
=@/^1.`
[*E.G~IS`
public TestMethod() wbKBwI5w
{ ///xx/weblogic60b2_win.exe !x /Z"
try{ Pb&+(j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Jy NY *
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oa|*-nw
SiteFileFetch fileFetch = new SiteFileFetch(bean); -^yc yZ
fileFetch.start(); XQ y|t"Vq>
} `5jB|r/
catch(Exception e){e.printStackTrace ();} [4yQbqe;
&=O1Qg=K
d(tf:@
} mK/P4]9g
AsF`A"Cdw<
TTak[e&j3
public static void main(String[] args) 3Ya6yz
{ 'UCx^-
new TestMethod(); Gf.o{
} #u(,#(P'#
} KftM4SFbK
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