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)); l* z"wA-
} USg,=YM
for(int i=0;i<nEndPos.length-1;i++) 9H/C(Vo
{ GOsOFs"I
nEndPos = nStartPos[i+1]; #p<(2wN
} 2f0mr?l)N
nEndPos[nEndPos.length-1] = nFileLength; =pBr_pGz=
} A*~BkvPr
} j+PLtE
PA*1]i#2M=
T/PmT:Qg`
//启动子线程 |'``pq/}_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t*J?#r
for(int i=0;i<nStartPos.length;i++) !>#gm7
{ ceuEsQ}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h0 Xc=nj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ? q_%
nStartPos,nEndPos,i); A%cJ5dF8~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j 8)*'T
fileSplitterFetch.start(); ,e^~(ITaq
} Zu*7t<W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G{!(2D4!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x];i? 4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "rrw~
nEndPos = " + nFileLength); {PkR6.XhR
// fileSplitterFetch[nPos.length-1].start(); q|}O-A*wa
<TTBIXV
/:v}Ni"6nF
//等待子线程结束 !sp`oM
//int count = 0; D_?dy4\
//是否结束while循环 82 dmlPwJC
boolean breakWhile = false; :NL[NbQYt
J|F!$m{
?[|A sw1t
while(!bStop) ^u2x26].
{ / */"gz%
write_nPos(); }qJ`nN8
Utility.sleep(500); /BN=Kl]
breakWhile = true; }G "EdhSl
icQQLSU5
($Op*bR
for(int i=0;i<nStartPos.length;i++) $DaQM'-
{ :r2d%:h%2
if(!fileSplitterFetch.bDownOver) }KYOde@
{ voFg6zoV_
breakWhile = false; kxR!hA8wv4
break; v cUGBGX_&
} dOK]Su
} )5`~WzA
if(breakWhile) }lXor~_i
break; DS9-i2
2r!- zEV
qnb/zr)p
//count++; hE E1i
//if(count>4) Z^BZH/I?
// siteStop(); PC\p>6xT
} J7sH]
e _(';Lk
-Mf-8zw8G
System.err.println("文件下载结束！"); ^oYRBEIJH
} 0|]d^bo
catch(Exception e){e.printStackTrace ();} LqXVi80
} 3ZN\F
]9~Il#
}ikN
//获得文件长度 g{ ;OgS3>
public long getFileSize() )H`V\H[0P
{ %Eugy
int nFileLength = -1; ;n.h!wmJ}
try{ G^cMY$?99
URL url = new URL(siteInfoBean.getSSiteURL()); /;TtMQt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m?gGFxo
httpConnection.setRequestProperty("User-Agent","NetFox"); YS@TQ?
*Z\AO'h=Z
$ce*W9`
int responseCode=httpConnection.getResponseCode(); Ly/
if(responseCode>=400) {>PEl;,-
{ B873UN
processErrorCode(responseCode); PJ=|g7I
return -2; //-2 represent access is error r,3\32[?
} `Z#':0Z
/MMnW$)
YNl".c
String sHeader; Pe-rwM
8_ascvs5
j/q&qrlL
for(int i=1;;i++) ~W={"n?=
{ `DE_<l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +]( #!}oH
//Utility.log(in.readLine()); `mI5Z*]-
sHeader=httpConnection.getHeaderFieldKey(i); h6IO;:P)
if(sHeader!=null) ji\&?%(B
{ Jamt@=
if(sHeader.equals("Content-Length")) ho)JY $#6
{ WJ)4rQ$o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .LDp.#d9r1
break; LitdO>%#2
} k ]T
} .XkD2~;
else +sTPTCLE
break; =y(*?TZH
} H+5+;`;
} Q1{9>NI
catch(IOException e){e.printStackTrace ();} FA\U4l-
catch(Exception e){e.printStackTrace ();} _>aP5g?Ep
4;>HBCM4-
oX*;iS X
Utility.log(nFileLength); lWd@
,jtaTG.>
+Wgfxk'{
return nFileLength; >)u{%@Rcy{
} 8^D1u`
]5K(}95&'
<`G-_VI
//保存下载信息（文件指针位置） +S+=lu _
private void write_nPos() FC~%G&K/q^
{ FV3[7w=D\
try{ fYzP4
output = new DataOutputStream(new FileOutputStream(tmpFile)); X$@qs9?)^
output.writeInt(nStartPos.length); Ryygq,>VD.
for(int i=0;i<nStartPos.length;i++) )FmIL(vu
{ @H3x51PT(m
// output.writeLong(nPos); kwqY~@W
output.writeLong(fileSplitterFetch.nStartPos); ADVS}d!;]
output.writeLong(fileSplitterFetch.nEndPos); k4!_(X%8
} V1GkX=H},
output.close(); VXlAK(
} lzz;L z
catch(IOException e){e.printStackTrace ();} )v11j.D
catch(Exception e){e.printStackTrace ();} ms!|a_H7r
} ywkRH
m2YsE j7
U* c'xoP
//读取保存的下载信息（文件指针位置） -'L~Y~'.
private void read_nPos() ,Vo[mB
{ H3`.Y$z
try{ ~'0ZW<X.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )n1[#x^I
int nCount = input.readInt(); F|R7hqf
nStartPos = new long[nCount]; <2]D3,.g.
nEndPos = new long[nCount]; _ WPt zL
for(int i=0;i<nStartPos.length;i++) \x\N?$`ANc
{ >T\@j\X4
nStartPos = input.readLong(); IbJl/N%o
nEndPos = input.readLong(); s$(%?,yf2
} >dJ~
input.close(); $+ N~Fa
} `W" ;4A
catch(IOException e){e.printStackTrace ();} O9o]4;
catch(Exception e){e.printStackTrace ();} UBj&T^j
} #d*gWwnx"
F u^j- Io
b62B|0i
private void processErrorCode(int nErrorCode) Ctn?O~u
{ NI.ROk1{+4
System.err.println("Error Code : " + nErrorCode); ;UUgqX#
} #$W0%7
4zt:3bWU
Iz'Et'w8!
//停止文件下载 q8-hbWNm4
public void siteStop() CY{!BV'
{ ^OX}y~'
bStop = true; 3 =c#LUA`
for(int i=0;i<nStartPos.length;i++) ;hV|W{=w
fileSplitterFetch.splitterStop(); :g' 'GqGZ
@Tq-3Um
W[qy4\.B
} ,EVPnH[F~
} ]W4{|%@H"
//负责部分文件的抓取 ;H`@x Lv*
**FileSplitterFetch.java XEagN:
*/ n-],!pL^
package NetFox; zS|4@t\__
JC-> eY"O2
C& XPn;f
import java.io.*; &Xh>w(u
import java.net.*; ^Go,HiB
Fw{#4
ov H'_'
public class FileSplitterFetch extends Thread { DO~[VK%|
|e+3d3T35
2#3`[+g<n
String sURL; //File URL 1cMLl6Bp>
long nStartPos; //File Snippet Start Position $d])>4eQ
long nEndPos; //File Snippet End Position FE{c{G<
int nThreadID; //Thread's ID |2n*Ds'
boolean bDownOver = false; //Downing is over TOKt{`2}
boolean bStop = false; //Stop identical +r//8&
FileAccessI fileAccessI = null; //File Access interface UBM#~~sM
$BgaLJs/O
+HRtuRv0T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &a e!lB
{ rP2h9Cb
this.sURL = sURL; D|m0Vj b
this.nStartPos = nStart; #>\SK
this.nEndPos = nEnd; );iJ9+ V}
nThreadID = id; fp\mBei
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LVm']_K(f
} @lWNSf
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2)\MxvfOh
public void run() 4g2`[<S
{ !jU{ }RCR
while(nStartPos < nEndPos && !bStop) xoj,>[7 D
{ Xf#;`*5
`MCtm(<
0F![<5X
try{ SSla^,MHef
URL url = new URL(sURL); k:j_:C&.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Z!y>k%6
httpConnection.setRequestProperty("User-Agent","NetFox"); cC/32SmY4
String sProperty = "bytes="+nStartPos+"-"; <oT1&C{
httpConnection.setRequestProperty("RANGE",sProperty); L>E;cDB
Utility.log(sProperty); Fq <JxamR
v?6*n>R
}1[s,
InputStream input = httpConnection.getInputStream(); cpw=2vnD
//logResponseHead(httpConnection); 7BwR ].
:OjmaP
WjR2:kT
byte[] b = new byte[1024]; Wf5;~RJC?
int nRead; oHv.EO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NT5##XOB
{ na9YlJ\
nStartPos += fileAccessI.write(b,0,nRead); \<xo`2b
//if(nThreadID == 1) )16+Pm8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5Uy*^C7M^
} UY({[?Se
LY)Wwl*wc
S *J{
Utility.log("Thread " + nThreadID + " is over!"); Wtk|}>Pf
bDownOver = true; 5%QYe]D
//nPos = fileAccessI.write (b,0,nRead); W)]&G}U<
} aZ{l6
catch(Exception e){e.printStackTrace ();} [PiMu,O[v
} SEg{Gso9b
} we!w5./Xm
T]1.":
TNN@G~@cm
//打印回应的头信息 AX6:*aZB
public void logResponseHead(HttpURLConnection con) ecH7")
{ Kf(Px%G6K
for(int i=1;;i++) E>*Wu<<
{ G,P k3>I'
String header=con.getHeaderFieldKey(i); *\}$,/m['
if(header!=null) 6|n3Q$p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sGNHA(;
Utility.log(header+" : "+con.getHeaderField(header)); vRW;{,d
else QQ{*j7i)
break; {g1R?W\LZ
} h:C:opa-=
} |x&4vHXR0
MNTVG&h
33eOM(`D[
public void splitterStop() *sB'D+-/
{ +lFBH(o]X
bStop = true; cp~6\F;c
} HA}q.L]#
?z-nY,'^uq
W=+AU!%
} XUR#|
&YD+s%OL
;O~FiA~`c
/* >0 o[@gJl
**FileAccess.java 5%V(eR
*//文件访问(定位，写) qM 1ZCt
package NetFox; aL;zN%Tw
import java.io.*; 2sG1Hox
CK4#ZOiaa
>QN-K]YLL
public class FileAccessI implements Serializable{ };"_Ku4#-
=^*EM<WG)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ']c;$wP
RandomAccessFile oSavedFile; -AVT+RE9z
long nPos; &,Loqr
~p{YuW[e
ouoIbA9X
public FileAccessI() throws IOException /4+zT?f
{ [5-IkT0
this("",0); g26_#4 P
} H|j]uLZ
;Z"Iv
iGj,B =35
public FileAccessI(String sName,long nPos) throws IOException rAW7Zp~KK
{ ;H71A[M T
oSavedFile = new RandomAccessFile(sName,"rw"); |FlB#
this.nPos = nPos; L.K|]]u
oSavedFile.seek(nPos); a5pM~.]
} Pjvb}q=
eL)m(
iny/K/5bf
public synchronized int write(byte[] b,int nStart,int nLen) %zEy.7Ux
{ Sa.nUj{M=
int n = -1; J?Q@f
try{ ^:f)XZ
oSavedFile.write(b,nStart,nLen); t)k;5B`> &
n = nLen; tId,Q>zH
} Ly v"2P
catch(IOException e) Jzy:^PObT
{ -\ew,y
e.printStackTrace (); z [u!C/
} l#+@!2z
6*>vie
hA&m G33
return n; YxU->Wi]G
} PIQd=%?'
`r\/5|M
d=\\ik8
} f!GFRMM1
P$clSJW
76c:*bZ
/* z!k
**SiteInfoBean.java }ri7@HCY4
*/ @_WZZ
package NetFox; $\20Vgu<
0PUSCka'6
C'sA0O@O
public class SiteInfoBean { $Nj'_G\}
/>PH{ l
8N#.@\'kz.
private String sSiteURL; //Site's URL =fhRyU:C[z
private String sFilePath; //Saved File's Path D42!#
private String sFileName; //Saved File's Name |*]<*qnZt
private int nSplitter; //Count of Splited Downloading File p8&rl|z|
1x+w|h
O#vIn}
public SiteInfoBean() y,<\d/YY@
{//nSplitter的缺省值为5 "*d%el\63
//default value of nSplitter is 5 %]F{aR
this("","","",5); /KO2y0`
} ?i~mt'O
7~D5Gy
x:]_z.5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H3ob 8+J
{ j(_6.zf
sSiteURL= sURL; /zir$
sFilePath = sPath; ( M3-S5
sFileName = sName; 5* ~EdT
this.nSplitter = nSpiltter; 0{Zwg0&
= o1&.v2j
nC9xN
} D r6u0rx8
lOIf4
-li;w tCS
public String getSSiteURL() >+ Im:fD
{ bGp3V. H
return sSiteURL; 7zXX& S
} h~&5;
DwXSlsN3v
(xBWxeL~
public void setSSiteURL(String value) k]A$?C0Q<%
{ {r?Ly15
sSiteURL = value; M_;hfpJZ
} N#X(gEV
>>h0(G|
XO/JnJ^B
public String getSFilePath() gvxOo#8]
{ l;;"v) C8
return sFilePath; ;J?zD9
} {F*81q\
>xm:?WR
9,AHC2kn%
public void setSFilePath(String value) /2]=.bLwz
{ 53?B.\
sFilePath = value; $4rMYEn08
} Ap%tm)@1
inv 5>OeG
Cn8w})B
public String getSFileName() rp,PhS
{ .h>tef
return sFileName; 7?~*F7F
} c_.4~>qw
w 8oIq*
L t.Vo
public void setSFileName(String value) /AUXO]
{ `F' >NNY
sFileName = value; !>QD42
} X!/
aQ.mvuMa7'
Qj/.x#T
public int getNSplitter() Bis'59?U_
{ Ni)/L( &
return nSplitter; g{$F;qbkO
} #~@Cl9[)D
<+${gu?^
@m(ja@YC
public void setNSplitter(int nCount) jM|-(Es.)
{ d"hW45L
nSplitter = nCount; jMB&(r
} !&8HA
} xO` O$ie
Oxhc!9F
~OQ/ |ws
/* T@,tlIM
**Utility.java k_%"#
*/ p:8&&v~I
package NetFox; x5)YZ~5
h`%}5})=
h oL"K
public class Utility { CYWL@<p,
Z4'8x h)-
P% ZCACzV
public Utility() | ?])]F
{ ZpTT9{PT=:
F8%.-.l)
2W 9N-t21
} fu6Ir,
57eA(uI
//线程睡眠 5 U{}A\q
public static void sleep(int nSecond) WTP~MJ#C
{ 2wki21oY
try{ )kiC/Y}k
Thread.sleep(nSecond); [#Y7iN&
} &>&UqWL
catch(Exception e) D4fHNk)kZ
{ 8KrqJN0\
e.printStackTrace (); ekx~svcC&A
} Ps!~miN|>
} U4hFPK<
%Vp'^,&S
//日志 2PrUI;J$
public static void log(String sMsg) .W)%*~ O!;
{ |X$O'Gf#n
System.err.println(sMsg); Nn%[J+F
} [b<AQFh<c
`96PY!$u
K_X10/#b&
public static void log(int sMsg) Pa-p9]gq
{ Lupug"p0
System.err.println(sMsg); hLf<-NM
} 7P$>T
} xJ18M@"j
i{ " g7
:n} NQzs
/* 2!+saf^-,
**TestMethod.java ev_4!+ko
*/ /T_@rm
package NetFox; ?onTW2cG;
vdLBf+Zi
'*6S0zt
public class TestMethod { <$]=Vaq
#M5R>&?Jqz
^t{2k[@
public TestMethod() .0b$mSV[
{ ///xx/weblogic60b2_win.exe KDODUohC
try{ d?uN6JH9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :t36]NM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *Fe
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~ojH$=K>d
fileFetch.start(); 8IX,q
} 7;T6hKWV[
catch(Exception e){e.printStackTrace ();} JXKqQxZ[X
ta\CZp
~T_4M
} /d\#|[S
Jbrjt/OG#I
\<bar ~
public static void main(String[] args) cn~M:LW23
{ )_\ZUem
new TestMethod(); 6ofi8(n[
} tXgsWG?v[H
} *)6:yn
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