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)); J'Gn M?M
} 3|g'1X}
for(int i=0;i<nEndPos.length-1;i++) b8Y1.y"#
{ nA5v+d-<T
nEndPos = nStartPos[i+1]; (9@6M8A
} E#8`X
nEndPos[nEndPos.length-1] = nFileLength; A]ciox$AjW
} a!xKS8-S==
} # 1I<qK
&+JV\
bWG}>{fj
//启动子线程 *>zr'Tt,W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O. @_2
for(int i=0;i<nStartPos.length;i++) S\s1}`pNm
{ ]p@7[8}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o+q4Vg9&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), //f[%j*>
nStartPos,nEndPos,i); %GjF;dJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h"M}Iz~|V?
fileSplitterFetch.start(); `N ;!=7y7Y
} 2t/ba3Rfk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wvmf[!V;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2u/(Q>#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s%;18V:pi
nEndPos = " + nFileLength); 5H;*Nj@
// fileSplitterFetch[nPos.length-1].start(); jHTaG%oh
Y#3m|b45n
I?Eh 0fI
//等待子线程结束 5|wQeosXxI
//int count = 0; hjaI&?w
//是否结束while循环 q1`uS^3`
boolean breakWhile = false; %\%1EZQ%
<iv9Mg}
qdvGBdF
while(!bStop) =}u;>[3
{ Ui'~d(F
write_nPos(); ;m{[9i`2
Utility.sleep(500); pBh[F5
breakWhile = true; .V 9E@_(
Nr6YQH*[
rOS fDv
for(int i=0;i<nStartPos.length;i++) zxTm`Dh;[
{ \d]&}`'4{f
if(!fileSplitterFetch.bDownOver) 9F ).i
{ wW]|ElYR=
breakWhile = false; uWvl<{2
break; nakhepLN
} uA*Op45
} N{L]H_=
if(breakWhile) E&GUg/d
break; 5rfGMk<
JrYpZ.Nh
$bD 3
//count++; ;x|4Tm
//if(count>4) Js'COO
// siteStop(); l?Bv9k.^?
} 3eFD[c%mN
ir3iW*5k
l{_>?]S5
System.err.println("文件下载结束！"); Pg|q{fc
} m-7^$
catch(Exception e){e.printStackTrace ();} VS1gg4tCv
} z| i$eF;x3
HC+(FymV
$BkdC'D
//获得文件长度 ,dK%[
public long getFileSize() G2 xYa$&][
{ E!C~*l]wJx
int nFileLength = -1; f.Q?-M
try{ 0'c<EJ
URL url = new URL(siteInfoBean.getSSiteURL()); =HYMX"s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d\'M ~VQ
httpConnection.setRequestProperty("User-Agent","NetFox"); rS{Rzs^@
nRb#M
FV!
int responseCode=httpConnection.getResponseCode(); 64hr|v
if(responseCode>=400) @fPiGu`L
{ 2p(K0PtX
processErrorCode(responseCode); OBF5Tl4
return -2; //-2 represent access is error oC>^V5
} #oJ9BgDry
akrEZ7A
N;;!ObVHnP
String sHeader; Z!^iPB0~D
d+[hB4!l2
YmNBtGhT
for(int i=1;;i++) W(a=ev2sa
{ O9:vPbn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M I/9?B
//Utility.log(in.readLine()); qf(!3
sHeader=httpConnection.getHeaderFieldKey(i); G{YJ(6etZ
if(sHeader!=null) %l5Uy??Z
{ A!W(>
if(sHeader.equals("Content-Length")) ^h4Q2Mv o
{ *.ZV.(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8.'%wOU@A
break; /'!F \ kz
} +w%MwPC7`
} ){L`hQ*=w
else v|CRiwx
break; J:M^oA'N:>
} P_lk40X
} f:=q=i
catch(IOException e){e.printStackTrace ();} {*yhiE,
catch(Exception e){e.printStackTrace ();} &HT PeB
|JnJ=@-y
6 @'v6 1'
Utility.log(nFileLength); vAHJP$x
|A[Le ;,
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return nFileLength; enDjP
} M5[AA/@
"72 _Sw
^#vWdOlt
//保存下载信息（文件指针位置） C(xdiQJh
private void write_nPos() \b{=&B[Q$'
{ Vdh5s292h
try{ kYmkKl_
output = new DataOutputStream(new FileOutputStream(tmpFile)); zl4Iq+5~6Q
output.writeInt(nStartPos.length); W5HC7o\4
for(int i=0;i<nStartPos.length;i++) maXQG&.F
{ KR?-<
// output.writeLong(nPos); (VU: &.
output.writeLong(fileSplitterFetch.nStartPos); ;~tKNytD`B
output.writeLong(fileSplitterFetch.nEndPos); HwiG~'Ah9
} SI4M<'fK
output.close(); o%RyE]pw,
} AL3zE=BL
catch(IOException e){e.printStackTrace ();} {[NBTT9&
catch(Exception e){e.printStackTrace ();} pR; AqDQ
} dl;^sn0s
G%Wjtrpj
OqHD=D[
//读取保存的下载信息（文件指针位置） wRi!eN?
private void read_nPos() -]A,SBs
{ GbBcC#0
try{ bt-y6,> +E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u4rGe!
int nCount = input.readInt(); m7cp0+Peo
nStartPos = new long[nCount]; [Xg?sdQCI
nEndPos = new long[nCount]; tb"UGa
for(int i=0;i<nStartPos.length;i++) v`*!Bhc-
{ u01x}Ff~6
nStartPos = input.readLong(); tg7%@SI5^-
nEndPos = input.readLong(); doW_vu
} 5O]ph[7
input.close(); _ ?xORzO
} B14z<x}Q
catch(IOException e){e.printStackTrace ();} R*'rg-d
catch(Exception e){e.printStackTrace ();} !%_}Rv!JT
} !J3g,p*
sJw#^l
CM!bD\5
private void processErrorCode(int nErrorCode) =M*31>"I0
{ E}b" qOV
System.err.println("Error Code : " + nErrorCode); 3.xsCcmP
} :-69,e
9]xOuCb
tF O27z@
//停止文件下载 k-*H=km
public void siteStop() L|u\3.:
{ Kj;Q;Ii
bStop = true; ;SagN
for(int i=0;i<nStartPos.length;i++) |Q@4F&k
fileSplitterFetch.splitterStop(); Nw/4z$].J
=NQDxt}
@9~6+BZOq
} g-bHf]'
} wC}anq>>
//负责部分文件的抓取 &)T5V
**FileSplitterFetch.java +%UfnbZ
*/ /hQTV!\u
package NetFox; kL* DU`
<V5(5gx
6:fe.0H9
import java.io.*; @_J~zo
import java.net.*; a{GPAzO+
[?Cv^t${+
LD0x 4zm$m
public class FileSplitterFetch extends Thread { .Wc<(pfa
~+/IzckrG
AD_")_B|i
String sURL; //File URL zN:VT&
long nStartPos; //File Snippet Start Position .!/DM-C
long nEndPos; //File Snippet End Position X6)-1.T&
int nThreadID; //Thread's ID I~-W4{
boolean bDownOver = false; //Downing is over x&@. [FJhO
boolean bStop = false; //Stop identical TMpV.iH
FileAccessI fileAccessI = null; //File Access interface 1I{vBeMj
|k\4\aLj
_)"-zbh}{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g=XvqD<
{ yT.h[yv"w
this.sURL = sURL; ^<}9#q/rt
this.nStartPos = nStart; ;}@.E@s%'
this.nEndPos = nEnd; a` s2 z
nThreadID = id; FAX|.!US*p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jAie[5
} MX2]Q
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;:4&nJ*qG
public void run() z"Miy
{ T~8==Z{[
while(nStartPos < nEndPos && !bStop) 7/&i'y
{ 6!*be|<&
w9<<|ZaU
xQ+UZc
try{ X ^8@T
URL url = new URL(sURL); ^~9fQJNs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Tec#eYe
httpConnection.setRequestProperty("User-Agent","NetFox"); L-? ?%_=
String sProperty = "bytes="+nStartPos+"-"; zkt`7Pg;J
httpConnection.setRequestProperty("RANGE",sProperty); v[{g"C
Utility.log(sProperty); z6)b XL[f
*:gx1wd
t~]n"zgovz
InputStream input = httpConnection.getInputStream(); d,8L-pT$FM
//logResponseHead(httpConnection); ' ^E7T'v%
VHyH't_&s
Oi%\'biM
byte[] b = new byte[1024]; e=Ko4Ao2y
int nRead; U6cpj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1j"G~TM
{ P{fT5K|
nStartPos += fileAccessI.write(b,0,nRead); 9: N[9;('
//if(nThreadID == 1) = >CADTU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M(8dKj1+
} {RH&mu
[U]^:sV)
Heh.CD)Q
Utility.log("Thread " + nThreadID + " is over!"); xY4g2Q J
bDownOver = true; @+Yql
//nPos = fileAccessI.write (b,0,nRead); SQ'\Kd=
} ,.DTJ7H+
catch(Exception e){e.printStackTrace ();} E:vgG|??
} H1>~,zc>E
} {*mf Is
K)b@,/5
K</EVt,U~
//打印回应的头信息 #NQpr
public void logResponseHead(HttpURLConnection con) ]8@s+N
{ qW+'#Jh@TV
for(int i=1;;i++) %hDx UZ#0
{ nilis-Bk_
String header=con.getHeaderFieldKey(i); I]Ev6>=;
if(header!=null) ]Q0m]OaT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~&HP}Q$#f
Utility.log(header+" : "+con.getHeaderField(header)); ^/]w}C#:d
else 4fauI%kc
break; }uP`=T!"8
} " GRR,7A
} &pHSX
qlSI|@CO
=jv3O.zq
public void splitterStop() rebnV&-
{ e~oh%l^C72
bStop = true; <<'%2q5
} BOt1J_;(rO
`vjn,2S}
)qSjI_qt5
} ]31>0yj[Q
4.Kl/b;
9*~bAgkWI
/* I]GGmN
**FileAccess.java !0-KB#
*//文件访问(定位，写) u00w'=pe)
package NetFox; Ic2Q<V}oq
import java.io.*; /cHUqn30a
\k4tYL5
=hRo#]{(K
public class FileAccessI implements Serializable{ %_Q+@9
Ec/&?|$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tJBj9{
RandomAccessFile oSavedFile; ^?M# |>
long nPos; )[b\wrc
M$u.lI
='A VI-go5
public FileAccessI() throws IOException <+y%k~("
{ "m#17J_
this("",0); K_!R
} eI,'7u4q
i?wEd!=w
T.(C`/VM
public FileAccessI(String sName,long nPos) throws IOException A_e&#O
{ /a,"b8
oSavedFile = new RandomAccessFile(sName,"rw"); 2# 72B
this.nPos = nPos; o|G'vMph
oSavedFile.seek(nPos); $^:s)Yv
} Qm_IU!b
WOg pDs
2dsXG$-W2
public synchronized int write(byte[] b,int nStart,int nLen) f9K+o-P.h
{ 7D(Eo{ue
int n = -1; 2Tp@;[!3
try{ &]"Z x0t5%
oSavedFile.write(b,nStart,nLen); _C@A>]GT
n = nLen; Qli#=0{`
} XX7zm_>+
catch(IOException e) C'~Eq3
{ lVv'_9yg
e.printStackTrace (); d\ I6Wn
} |.*nq
GIb,y,PDB
ARUzEo gcf
return n; e0<Wed
} u>ZH-nw O
BOflhoUX
y(ceEV
} 23d*;ri5
redMlHM
jl>jy6T
/* 0fGt7 "Q
**SiteInfoBean.java xX?9e3(
*/ d>gQgQ;g
package NetFox; r>#4Sr
!J&UO/q.
IG.!M@_
public class SiteInfoBean { HTLS$o;Q
0"}=A,o(w
1l5'N=hL
private String sSiteURL; //Site's URL +H:}1sT;n
private String sFilePath; //Saved File's Path DHg)]FQ/
private String sFileName; //Saved File's Name Or#KF6+ut
private int nSplitter; //Count of Splited Downloading File Avww@$
{SF'YbY
;Q8`5h
public SiteInfoBean() i>7]9gBm1q
{//nSplitter的缺省值为5 X2|&\G9c
//default value of nSplitter is 5 \3&1iA9=)
this("","","",5); 6d`qgEM3
} XXw>h4hl
NQxx_3*4O
D GL=\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [Kg3:]2A
{ C);3GPp
sSiteURL= sURL; XRmE
sFilePath = sPath; \_(|$Dhq
sFileName = sName; nx(jYXVT
this.nSplitter = nSpiltter; T[evh]koB
C#V_Gb
}uwZS=pw
} 3*T/ 7\
C|V5@O?;&
g"~`\xhx
public String getSSiteURL() EQe$~}[
{ SdF+b+P]
return sSiteURL; d\R "?Sg
} "/G]M&
l)e6*sDZ,
b")O#v.
public void setSSiteURL(String value) Z;z,dw
{ m 7S`u
sSiteURL = value; 27i-B\r
} ^RE[5h6^q
L&KL]n
P2&0bNY
public String getSFilePath() HVdB*QEH
{ xS(VgP&YGO
return sFilePath; Uw]o9 e0S
} }vU^gPH
7~r_nP_
<Mndr8 H
public void setSFilePath(String value) ay =B<|!
{ L#?mPF
sFilePath = value; s",G w]8
} j115:f
]Q,&7D Ah
w`EC6ZN
public String getSFileName() GTi=VSGqF
{ !3<b#QAXRG
return sFileName; i%GiWanG
} Z`f?7/"B
1g,Ofr
B}P!WRNmln
public void setSFileName(String value) 1Vkb}A,'
{ [wk1p-hf
sFileName = value; x:i,l:x
} V["'eJA,,
TV|Z$,6l
r:PYAb=g
public int getNSplitter() &1Y7Ne
{ uJ=d!Kn
return nSplitter; ~]24">VZf
} *Kpw@4G
*ZV3]ig2$
.AQTUd(_
public void setNSplitter(int nCount) qfdL *D
{ qo}yEl1
nSplitter = nCount; PdEPDyFkh
} :fDzMD
} :`K2?;DC8
NiEz3ODSi
Xq_hC"s
/* 2s=zT5
**Utility.java GDs/U1[*
*/ r"7PSJ
package NetFox; tJ*/5k &
QE pCU)
Xgl %2'
public class Utility { mhM;`dl
Y O|hwhe_
M?Fv'YE
public Utility() qJJ 5o?'
{ A k~|r#@
t\]kVo)
'SXLnoeTa
} ;1s;"
Vx:uqzw#
//线程睡眠 mE=Tj%+x
public static void sleep(int nSecond) .76Z
{ lfG',hlI;
try{ O$x +>^
Thread.sleep(nSecond); xnJ#}-.7
} z:N?T0b(
catch(Exception e) aO}p"-'
{ mI\[L2x
e.printStackTrace (); >l=jJTJ;q
} ?)[=>Kp
} Sj:c {jyJd
GY5JPl
//日志 xOr"3;^
public static void log(String sMsg) O>I%O^
{ +3M1^:
System.err.println(sMsg); 1d842pt
} <;@E .I\N
[h_d1\ Cr
i-#Dc(9
public static void log(int sMsg) foBF]7Bz?
{ TwF.UL@G%
System.err.println(sMsg); [,;O$j}
} ONZ(0H{ 1$
} ~]Av$S
_,v>P2)
9.,IqnP
/* 3g56[;Up?
**TestMethod.java Gm> =s
*/ I~E&::,
package NetFox; |Om9(xT
D><^7nr%
6-\' *5r
public class TestMethod { zGc]*R
.Iz JJp
(LMT'
public TestMethod() 4N1)+W8k*
{ ///xx/weblogic60b2_win.exe ;5
try{ :T>OJ"p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l)~$/#k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h#dfhcU>
SiteFileFetch fileFetch = new SiteFileFetch(bean); wzmQRn;s
fileFetch.start(); >I0 a$w
} Jh36NE8r
catch(Exception e){e.printStackTrace ();} 0W_u"UY$c
,1.Td=lY$
w_;$ahsu~
} UZ6y3%G3^
~Y;Z5e=
_;/+8=
public static void main(String[] args) (]VY==t~
{ 7VdxQ T
new TestMethod(); Au{b1n
} 90-s@a3B-j
} R:ecLbC
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