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)); )edM@beY_
} }(tGjx]
for(int i=0;i<nEndPos.length-1;i++) yJp&A
{ W: ?-d{
nEndPos = nStartPos[i+1]; WejY b;KS
} W&!Yprr
nEndPos[nEndPos.length-1] = nFileLength; >uuX<\cW
} C#-x 3d-{
} cE*|8'rSf
~!A,I 9
i2j)%Gc}
//启动子线程 %?wuKZLnc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N{9<Tf*
for(int i=0;i<nStartPos.length;i++) `z=MI66Nl
{ <![T~<.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZY/at/v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,OasT!Sr
nStartPos,nEndPos,i); sG VC+!E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MJg^ QVM
fileSplitterFetch.start(); E>g'!
} zWY6D4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @W @L%<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g{J3Ba
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9M7P]$^
nEndPos = " + nFileLength); ev?>Nq+Z
// fileSplitterFetch[nPos.length-1].start(); '[-/Xa['
K0E;4r
hsE!3[[
//等待子线程结束 }]s~L9_z['
//int count = 0; *TXq/ 3g
//是否结束while循环 R*[ACpxr
boolean breakWhile = false; gR(c;
KcU,RTE
=;{S>P!I(t
while(!bStop) Z9sg6M@s
{ 8@qahEgQ
write_nPos(); MoX*e
Utility.sleep(500); MYx*W7X
breakWhile = true; F@I_sGCcb
c"z%AzUV'
9/%|#b-z
for(int i=0;i<nStartPos.length;i++) N4Lk3]
{ iK#{#ebAoW
if(!fileSplitterFetch.bDownOver) T5Fah#-4
{ w}1)am&pD
breakWhile = false; Sph+kiy|
break; /d=$,q1
} 3|?fGT;P
} *m"mt
if(breakWhile) O:x=yj%^
break; 8zGzn%^
82=][9d #
1Jd:%+T
//count++; RTU:J67E
//if(count>4) S;c=6@"
// siteStop(); {l6]O
} W[?B@sdSZ
)5t_tPv
Qpc{7#bp
System.err.println("文件下载结束！"); xl9l>k6,
} lxd<^R3i#^
catch(Exception e){e.printStackTrace ();} dg!sRm1iZ:
} UEeqk"t^
uJO*aA{K
/Yh([P>
//获得文件长度 kp$ILZ
public long getFileSize() #X8[g_d/
{ TXaXJIp
int nFileLength = -1; 4|e#b(!
try{ Ov|j{}=L=9
URL url = new URL(siteInfoBean.getSSiteURL()); b?^n'0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w#1dO~
httpConnection.setRequestProperty("User-Agent","NetFox"); t}tKm
4Klfnki
QXz!1o+"
int responseCode=httpConnection.getResponseCode(); S&Sf}uK
if(responseCode>=400) zXD@M{
{ 4[ra
processErrorCode(responseCode); S'O0'5U@
return -2; //-2 represent access is error JU@$(
} + ND9###
.3&m:P8zV
;H=6u
String sHeader; [Ok8l='
e&5K]W0{
hJ<2bgQo
for(int i=1;;i++) 7S`H?},sR
{ EyeLC6u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T82_`u
//Utility.log(in.readLine()); YZ>cE#
sHeader=httpConnection.getHeaderFieldKey(i); g)9/z
if(sHeader!=null) -0`hJ_(
{ n`,Q:
if(sHeader.equals("Content-Length")) kUt9'|9!
{ m&q;.|W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hF~B&^dd.
break; ]| yH8m
} twtDyo(\
} ,fw[J
else H1[aNwLr
break; zi ,Rk.
} h[]N=X
} *LRGfk+h
catch(IOException e){e.printStackTrace ();} ^sKXn:)
catch(Exception e){e.printStackTrace ();} MUrY>FYgx
nf4P2<L!
IMZKlU3
Utility.log(nFileLength); 'dzp@-\
L@Z &v'A
4.'EEuRw\}
return nFileLength; + LwoBn>6
} D$cMPFa2Nt
*ls6#j@
bwJi[xF
//保存下载信息（文件指针位置） n@Ag`}
private void write_nPos() eFQi K6`i
{ 4Le5Ms/
try{ Z|c9%.,
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lvq]SzOw
output.writeInt(nStartPos.length); FQFENq''B
for(int i=0;i<nStartPos.length;i++) ej;taKzj
{ pJz8e&wyLM
// output.writeLong(nPos); {yHfE,
output.writeLong(fileSplitterFetch.nStartPos); L\ %_<2
output.writeLong(fileSplitterFetch.nEndPos); O[y`'z;C
} ?/(K7>`
output.close(); b-?o?}*
} Z?.*.<"Sj
catch(IOException e){e.printStackTrace ();} v+#j>
catch(Exception e){e.printStackTrace ();} dYd~9
} X6,9D[Nw
^wa9zs2s;/
<k](s
//读取保存的下载信息（文件指针位置） 0EOX@;}
private void read_nPos() s%oAsQ_y
{ #P#R~b]
try{ [bG>qe1}&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $O'2oeM
int nCount = input.readInt(); *fSM'q;
nStartPos = new long[nCount]; %j">&U.[
nEndPos = new long[nCount]; p2vBj.*J
for(int i=0;i<nStartPos.length;i++) jtv Q<4
{ ogqV]36Idh
nStartPos = input.readLong(); wsrx|n[]
nEndPos = input.readLong(); V|\A?
} $>=Nb~t!/
input.close(); 0 '7s
} +^?-}v
catch(IOException e){e.printStackTrace ();} {*;]I?9Al
catch(Exception e){e.printStackTrace ();} 2^6TrZA7M6
} ?d<:V.1U@
]B3FTqR{i
uV_)JZW,L
private void processErrorCode(int nErrorCode) q7&yb.<KD.
{ $|(|Qzi%
System.err.println("Error Code : " + nErrorCode); 'c0'P%[5A
} =t$mbI
:{:?D\%6
s2?,'es
//停止文件下载 \'+{X(]
public void siteStop() o U}t'WU
{ v^W?o}W
bStop = true; Cw[Od"B\?U
for(int i=0;i<nStartPos.length;i++) qM>OE8c#/
fileSplitterFetch.splitterStop(); n,jE#Z.D
s.;KVy,=Bu
h:jI
} e4qk>Cw
} EO/cW<uV'
//负责部分文件的抓取 aC yb-P
**FileSplitterFetch.java ;Nf hKu%K
*/ Ag#5.,B-
package NetFox; O\?5#.
>9tkx/J
m0A@jWgd
import java.io.*; 2x`xyR_Q.R
import java.net.*; O3C)N I\i
x|v[Dxf]
DAMpR3
public class FileSplitterFetch extends Thread { ;/";d]j
t66f 7AR
W_BAb+$aF
String sURL; //File URL DtF![0w/
long nStartPos; //File Snippet Start Position R!/,E
long nEndPos; //File Snippet End Position dVVvG]
int nThreadID; //Thread's ID -wtTq ph'
boolean bDownOver = false; //Downing is over krr-ZiK
boolean bStop = false; //Stop identical hDB`t $
FileAccessI fileAccessI = null; //File Access interface v;bM.OL
vN0L(B
U-~*5Dd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^C:{z)"h
{ b#Fk>j
this.sURL = sURL; p9&gEW
this.nStartPos = nStart; o}mhy`}
this.nEndPos = nEnd; Pa+AF
nThreadID = id; t7*G91Hoq&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0i`v:Lq%
} k5fH;
AF*ni~
]xJ'oBhy
public void run() ^Kw&=u
{ a8bX"#OR&N
while(nStartPos < nEndPos && !bStop) u,Q_WR-wJ
{ JO&;bT<
pu2wEQ
,);= (r9
try{ u-%r~ }
URL url = new URL(sURL); f\x@ C)E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _o&,
httpConnection.setRequestProperty("User-Agent","NetFox"); P;L)1 g
String sProperty = "bytes="+nStartPos+"-"; uHUvntr
httpConnection.setRequestProperty("RANGE",sProperty); fw:7Q7 qo
Utility.log(sProperty); 2rR@2Vsw2
?b*/ddIs
EaM"=g
InputStream input = httpConnection.getInputStream(); r21?c|IP
//logResponseHead(httpConnection); zH=/.31Q
%S >xSqX
_ bXVg3oDt
byte[] b = new byte[1024]; k\mXo-:V6
int nRead; xP{HjONu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {*M>X}voS
{ `eMrP`
nStartPos += fileAccessI.write(b,0,nRead); 1BMV=_
//if(nThreadID == 1) 0^<Skm27"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 12:h49AP
} Y91 e1PsV
NSMjr_
@b::6n/u
Utility.log("Thread " + nThreadID + " is over!"); OQytgXED
bDownOver = true; Edf=?K+\!i
//nPos = fileAccessI.write (b,0,nRead); g33<qYxP
} XI%RneuDr:
catch(Exception e){e.printStackTrace ();} +X* F<6mZ
} ' D)1ka.
} K)Df}fVOc
CU#L *kz
eHVdZ'%x
//打印回应的头信息 r!=]Q}`F
public void logResponseHead(HttpURLConnection con) sW]yuu!/
{ vF.?] u
for(int i=1;;i++) Vr&el
{ .KT 7le<Zm
String header=con.getHeaderFieldKey(i); dAYI DE
if(header!=null) Dh\S`nfFq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b[J-ja.
Utility.log(header+" : "+con.getHeaderField(header)); Eonq'Re$
else %K&+~CJE
break; %mK3N2N$
} 8~&F/C*
} 6pM"h5hA
W\I$`gyC/
4)z3X\u|Z2
public void splitterStop() T8,k77
{ ALE808;|
bStop = true; D:YN_J"kV
} l1-4n*fU
uD.
>Jm-2W5J
} \&eY)^vw
=gMaaGg p,
'+)6#/*
/* DHh+%|e
**FileAccess.java K?h[.`}
*//文件访问(定位，写) (,- 5(fW
package NetFox; g2[K<
import java.io.*; L0X&03e=e:
]uBT &
g>6:CG"
public class FileAccessI implements Serializable{ iyA*JCD
4/*]`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KW&nDut
RandomAccessFile oSavedFile; M,b<B_$
long nPos; YYTO,4
&GXtdO>;Zv
pj!k|F9
public FileAccessI() throws IOException W@:^aH
{ ]h #WkcXQ
this("",0); GIl:3iB49
} |RHO+J
H/cs_i
H"Q(2I
public FileAccessI(String sName,long nPos) throws IOException 3mpP|b"
{ {M`
oSavedFile = new RandomAccessFile(sName,"rw"); L\QQjI{
this.nPos = nPos; 3M}AxEu
oSavedFile.seek(nPos); '4J&Gpx
} ,DE(5iDS
'bLP~
er(8}]X8Q
public synchronized int write(byte[] b,int nStart,int nLen) CMC?R,d
{ P/FrE~
int n = -1; MB}:GY?
try{ i0ILb/LS
oSavedFile.write(b,nStart,nLen); 3cmbK
n = nLen; 5|yZEwq
} !Bag}|#
catch(IOException e) =L:[cIRrT;
{ <2n'}&F
e.printStackTrace (); Wl,%&H2S<
} I'x$,s
G i$
+ckMT3
return n; slu$2-H
} 08`f7[JQo]
?+3R^%`V
\U==f&G?J
} {]+ jL1
TAXd,z N
F?!FD>L{`
/* BfX%|CWh
**SiteInfoBean.java 0Wa#lkn$I
*/ g;$E1U=R-E
package NetFox; HkW/G[7x&
lTn;3'
5fU!'ajaN7
public class SiteInfoBean { )URwIe{
g+:$X- r
#N; $
private String sSiteURL; //Site's URL cB{%u '
private String sFilePath; //Saved File's Path %rFP#L
private String sFileName; //Saved File's Name }%_qx|(P|t
private int nSplitter; //Count of Splited Downloading File H!p!sn
%(fL?
|d5ggf.w
public SiteInfoBean() Q%rVo4M#2
{//nSplitter的缺省值为5 #1MKEfv(~
//default value of nSplitter is 5 2q12yY f
this("","","",5); N0]z/}hd@
} pMOD\J:l,
N[>:@h
"_t4F4z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X88F>1}
{ 8a7YHUL<3i
sSiteURL= sURL; QT_Srw@
sFilePath = sPath; L+_8QK<
sFileName = sName; Xu6jHJ@x
this.nSplitter = nSpiltter; JFe4/ V
g .3f2w
$,!hD\a
} p#)e:/Qy
,bxz]S1W
VcP:}a< B\
public String getSSiteURL() 7Ez}k}aR<
{ GM:,CJ?
return sSiteURL; 4>l0V<
} 6{L F-`S%
V!mWn|lf
6ezcS}:+
public void setSSiteURL(String value) r8sdzz%
{ q5!0\o:
sSiteURL = value; /\~l1.6`
} R;%^j=Q
NOV.Bs{ yL
!!9{U%s
public String getSFilePath() .-J`d=Krp
{ j|ozGO
return sFilePath; [;<<4k(nL
} wI*Y{J
4yhcK&
O(odNQy~
public void setSFilePath(String value) r;9z5'
{ f;R>Pr;rD
sFilePath = value; fD0{5
} .6LS+[
$kv@tzO
{Wh BoD
public String getSFileName() 8*vFdoE_oO
{ li@kLh
return sFileName; Urn
} :u AjV
tO7I&LNE
bZu$0IG
public void setSFileName(String value) L,6MF,vx
{ 6I"C~&dt
sFileName = value; A^8x1ydZ
} Mg+4huT
-gB{:UYi3
!1("(Eb
public int getNSplitter() _$!`VA%
{ pVY4q0@
return nSplitter; D]jkR} t
} _g65pxt =Z
&u("|O)w$
sLNNcj(Cy>
public void setNSplitter(int nCount) Y4`QK+~fH
{ V>AS%lXj
nSplitter = nCount; f P+QxOz
} I-TlrW=t
} ,^HS`!s[ E
(N7O+3+G
ve6x/ PD
/* SijS5irfk
**Utility.java $ND90my
*/ |g+!
package NetFox; loLKm]yV
}Iip+URG
,2,W^HJ
public class Utility { j|k@MfA
f'i6QMk\&
v O PMgEI
public Utility() !n:uiwh
{ ;|;iCaD a+
(ZS/@He
Jb9F=s+
} ~+=E"9Oo
UUGe"]V^g:
//线程睡眠 YlrB@mE0n$
public static void sleep(int nSecond) ]r!QmWw~V
{ 6A.P6DW
try{ {79qtq%W{
Thread.sleep(nSecond); *O5:
} l!/!?^8|f
catch(Exception e) >GmN~"iJ
{ T30Zk*V
e.printStackTrace (); ",T`\8&@e
} h^Qh9G0dn
} ETe-
"U*5Z:8?9
//日志 YroNpu]s
public static void log(String sMsg) .x>HA^4
{ %OEq,Tb
System.err.println(sMsg); [1Uz_HY["3
} i_NJ -K
fQP,=
H@Q`
public static void log(int sMsg) puA|NT
{ cFDxjX?~
System.err.println(sMsg); 8!;$qVt
} ]{Z8
} V8tghw
so*/OBte
VjY<\WqbS
/* `On3/gU|
**TestMethod.java P,U$ %C!
*/ d-h"JZ9
package NetFox; z,avQR&
}I]W'<jY
ifvU"l
public class TestMethod { GZ"&L?ti
ydB$4ZB3[
mbGcDG[HQ
public TestMethod() *Wso3 6an
{ ///xx/weblogic60b2_win.exe p&\K9hfi
try{ XddHP;x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d+Ds9(gV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +2Z#M
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6< >SHw
fileFetch.start(); *%I[ ke *
} 4~Dax)
catch(Exception e){e.printStackTrace ();} C 0>=x{,v
,z G(u 1
%<AS?Ry
} _[F@1NJ
Qm; BUG]
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public static void main(String[] args) gJk[Ja
{ q1w|'V
new TestMethod(); ,z[(k"
} t$5jx
} ZtR&wk
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