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)); a`E1rK'
} o"Mhwh
for(int i=0;i<nEndPos.length-1;i++) ? f>pKe
{ +/|t8zFWs
nEndPos = nStartPos[i+1]; fKkH [
} 4lsg%b6_%,
nEndPos[nEndPos.length-1] = nFileLength; >sl#2,br
} p`mNy o'
} 7>$&CWI
P;DGs]PF
96]!*}
//启动子线程 Z+M* z;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N~0~1 WQn
for(int i=0;i<nStartPos.length;i++) yK"T5^o
{ "CcdwWM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >Ndck2@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #cdrobJ
nStartPos,nEndPos,i); ~;uc@GGo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m2h@*
fileSplitterFetch.start(); *%;+3SV
} RwyRPc_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l:$i}.C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TOC2[mc'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~&\}qz3
nEndPos = " + nFileLength); U,e'vS{
// fileSplitterFetch[nPos.length-1].start(); H\!p%Y
i?0+f}5<p
`%oJa`
//等待子线程结束 4k4 d%
//int count = 0; ~+OAAkJ9
//是否结束while循环 l Taw6;
boolean breakWhile = false; [:*Jn}
8AgKK=C=
kD.KZV
while(!bStop) jSc!"Trl]
{ bxR6@
write_nPos(); BfOQ/k))
Utility.sleep(500); NuQ l
breakWhile = true; M`u&-6
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Tc.k0n%W:b
for(int i=0;i<nStartPos.length;i++) BK;Gh0mp
{ {.mPe|
if(!fileSplitterFetch.bDownOver) i0/RvrLc
{ Pua|Z x
breakWhile = false; {>rGe#Vu
break; 6G0Y,B7&
} {$H-7-O$
} mA2L~=v#
if(breakWhile) OJ!=xTU%h
break; r)xkpa5
+$y%H
Tt\h#E
//count++; SSo7 U
//if(count>4) vv0+F6 @
// siteStop(); Nt'6Y;m!
} ,C97|6rC
rO3.%B}
|0N6]%r
System.err.println("文件下载结束！"); MFzJ 8^.1R
} b;k3B7<
catch(Exception e){e.printStackTrace ();} R.'-jvO
} :plN<8
4Fs5@@>X
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//获得文件长度 l>){cI/D#
public long getFileSize() '^10sf`"
{ YDxEWK<
int nFileLength = -1; 1r?hRJ:'
try{ 0+dc
URL url = new URL(siteInfoBean.getSSiteURL()); u(W+hdTap=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wY'w'%A?
httpConnection.setRequestProperty("User-Agent","NetFox"); ?_V&~?r
1XXuFa&
uw>O|&!
int responseCode=httpConnection.getResponseCode(); [Zxv&$SQ
if(responseCode>=400) 'L$}!H1y
{ o!@}&DE|*L
processErrorCode(responseCode); (<KFA,
return -2; //-2 represent access is error Wb{0UkApJ
} {a9( Qi
' Ih f|;r
z&KrG
String sHeader; JG/Pc1aK
"&Rt&S
pB5#Ho>S
for(int i=1;;i++) rHaj~s 4
{ )sZJH9[K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !%X#;{
//Utility.log(in.readLine()); :tf'Gw6v
sHeader=httpConnection.getHeaderFieldKey(i); 6m$lK%P{1
if(sHeader!=null) hH(w O\s
{ U]AJWC6
if(sHeader.equals("Content-Length")) .$"13"
{ q"9 2][}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cKEDRX3
break; h"3Mj*s
} N5d)&a 7?
} -\[H>)z]RB
else Kg6[
break; e%_J O7
} OaeX:r+&Q
} AEd]nVV Q
catch(IOException e){e.printStackTrace ();} *hvC0U@3
catch(Exception e){e.printStackTrace ();} F?+\J =LT
i@m@]-2
H ]z83:Z
Utility.log(nFileLength); "K c/Cs2[
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q,m+W='
return nFileLength; lx\9Y8
} q5xF~SQGw2
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h<<uef9
//保存下载信息（文件指针位置） `F`{s`E)
private void write_nPos() .L@gq/x)
{ #1De#uZ
try{ giYlLJA*}
output = new DataOutputStream(new FileOutputStream(tmpFile)); rt0_[i
output.writeInt(nStartPos.length); 8AQ__&nT
for(int i=0;i<nStartPos.length;i++) wQ9?Z.-$
{ nq5qUErew
// output.writeLong(nPos); 6^e}^~|
output.writeLong(fileSplitterFetch.nStartPos); 10d.&vNw
output.writeLong(fileSplitterFetch.nEndPos); IhjZ{oV/@
} XY^]nm-{I
output.close(); 35%\"Y?
} 0fzHEL
catch(IOException e){e.printStackTrace ();} y|/[;
catch(Exception e){e.printStackTrace ();} aqEmF
} {/}%[cY=
D/YMovH%
i_e%HG
//读取保存的下载信息（文件指针位置） Dv"HFQuF
private void read_nPos() Marx=cNj
{ UQ#t &
try{ GIZw/L7Yb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ge7Uety
int nCount = input.readInt(); 9? y&/D5O
nStartPos = new long[nCount]; cq0-Dd9^&
nEndPos = new long[nCount]; H~ E<ek'~
for(int i=0;i<nStartPos.length;i++) %<0'xJ%%Q
{ [\3W_jR
nStartPos = input.readLong(); |Kb m74Z%
nEndPos = input.readLong(); FBxg^g%PB@
} MfZamu5+F
input.close(); $p|Im,
} ^Na3VP
catch(IOException e){e.printStackTrace ();} M}e}3w
catch(Exception e){e.printStackTrace ();} '*B%&QC-
} <?>tjCg'
o~7D=d?R
Tq?7-_MLC$
private void processErrorCode(int nErrorCode) 5=#2@qp
{ uJ`:@Z^J
System.err.println("Error Code : " + nErrorCode); xLSf /8e
} 4sq](!A
Ihp Ea,v)
#&X5Di[A
//停止文件下载 iNr&;
public void siteStop() ,N1pww?
{ GkpYf~\Q
bStop = true; n^|SN9_r
for(int i=0;i<nStartPos.length;i++) l >~Rzw
fileSplitterFetch.splitterStop(); =o4gW`\z
\%&):OD1
D"gv:RojD
} C8W_f( i~
} OS-k_l L
//负责部分文件的抓取 f0879(,i
**FileSplitterFetch.java U(gYx@
*/ (mplo|>
package NetFox; ~O~iP8T
:{ iK 5
zZ,"HY=jN
import java.io.*; ++n_$Qug
import java.net.*; xR8y"CpE
~ mzX1[
10Q!-K),p
public class FileSplitterFetch extends Thread { uFA}w:Fm
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String sURL; //File URL +|Izjx]ZV
long nStartPos; //File Snippet Start Position `A9fanh
long nEndPos; //File Snippet End Position *{,}pK2*
int nThreadID; //Thread's ID X.sOZb?$
boolean bDownOver = false; //Downing is over g&{CEfw&
boolean bStop = false; //Stop identical SAiaC _
FileAccessI fileAccessI = null; //File Access interface k[)/,1
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r KYQ 8T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &@FufpPw/
{ lL'Bop@
this.sURL = sURL; qI>,PX
this.nStartPos = nStart; yuC|_nL
this.nEndPos = nEnd; &dPUd~&EL
nThreadID = id; Yxy!&hPLv:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9oIfSr,y
} Sk:x.oOZ
:|8!w
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public void run() [nG[ x|;|
{ ?9%$g?3Z
while(nStartPos < nEndPos && !bStop) TqSjL{l%
{ X#Ob^E%J
v,Zoy|Lu
[kTckZv
try{ nch#DE82
URL url = new URL(sURL); f:t j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6q8PLyIp
httpConnection.setRequestProperty("User-Agent","NetFox"); r9*6=*J|
String sProperty = "bytes="+nStartPos+"-"; 65nK1W`i
httpConnection.setRequestProperty("RANGE",sProperty); g6+5uvpd
Utility.log(sProperty); E62_k 0q
Ls+vWfF=#
ej7L-~lxQ
InputStream input = httpConnection.getInputStream(); 9R">l5u
//logResponseHead(httpConnection); 4 L 5$=V
2a;[2':
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byte[] b = new byte[1024]; c[T@lz(!
int nRead; cltx(C>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qA[cF$CIl)
{ EG|_YW7
nStartPos += fileAccessI.write(b,0,nRead); Yg}b%u,Q
//if(nThreadID == 1) o^'QGs"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $d,/(*Y#-
} pFV~1W:
uH(M@7"6_!
|Qb@.
Utility.log("Thread " + nThreadID + " is over!"); xj9xUun
bDownOver = true; *K& $9fah
//nPos = fileAccessI.write (b,0,nRead); F(ZczwvR
} dWu;F^
catch(Exception e){e.printStackTrace ();} Lxv6\3I+
} {;m|\652B
} of GoaH*h
52NI{"
J qmL|S)
//打印回应的头信息 ggrkj0
public void logResponseHead(HttpURLConnection con) $e{[fmx
{ 7G7"Zule*j
for(int i=1;;i++) pe>?m^gz[
{ s}yN_D+V
String header=con.getHeaderFieldKey(i); TA8
if(header!=null) A`Rs n\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F\v~2/J5v
Utility.log(header+" : "+con.getHeaderField(header)); So75h*e
else R,BINp
break; h(GSM'v
} ,b5vnW\
} 6'x3g2C/
g3yZi7b5FU
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public void splitterStop() B#}EYY
{ mxu!$wx
bStop = true; uHRxV"@}[1
} "c?31$6
xn@oNKD0
g>#}(u!PH
} | +uc;[`
th<>%e}5c
Oqt{ uTI~
/* d(@ ov^e-
**FileAccess.java yW\kmv.O
*//文件访问(定位，写) _3NH"o d
package NetFox; 8H T3C\$s
import java.io.*; +F%tBUY{<
Ct zWdo.
3xKgj5M
public class FileAccessI implements Serializable{ [0]J 2
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 86!$<!I
RandomAccessFile oSavedFile; $ER9u2
long nPos; F-M)6&T
'H4?V
B2KBJ4rI[1
public FileAccessI() throws IOException FFe{=H,=
{ p:eaZ
this("",0); B/^o$i
} H0yM`7[y
e 'F:LMX
sY?wQ:
public FileAccessI(String sName,long nPos) throws IOException rx@i.+
{ !,rF(pz
oSavedFile = new RandomAccessFile(sName,"rw"); D~|q^Ms,%
this.nPos = nPos; U.b|3E/^
oSavedFile.seek(nPos); (<@`MPI\@
} iel@"E 4
9'(m"c_
"DH>4Q] d
public synchronized int write(byte[] b,int nStart,int nLen) U!K#g_}
{ QUfF>,[sv
int n = -1; W7@Vma`
try{ %`\Qtsape
oSavedFile.write(b,nStart,nLen); #JY>
n = nLen; "3|OB, <;:
} -j:yEZ4Oy
catch(IOException e) GU9p'E
{ .2_xTt
e.printStackTrace (); m(EVC}Y
} :S7[<SwL
57]La^#
tA'5ufj*:
return n; .I$+ E
} lz1cLl m
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opu)9]`z
} Snp(&TD<<
t]iKU@3
%K7;ePu
/* Z!jJ93A"
**SiteInfoBean.java Ke]'RfO\
*/ eb6y-TwY
package NetFox; {ot6ssT=D
=<zlg~i
"(kiMog-
public class SiteInfoBean { E9t8SclV
"Vp:Sq9y
l8_RA
private String sSiteURL; //Site's URL fA[T5<66
private String sFilePath; //Saved File's Path :Z_abKt
private String sFileName; //Saved File's Name Ir*{IVvej
private int nSplitter; //Count of Splited Downloading File +qqCk
"{3|(Qs
PI,2b(`h_
public SiteInfoBean() r>PKl'IbE
{//nSplitter的缺省值为5 )KkV<$
//default value of nSplitter is 5 LfK/wSvWw
this("","","",5); SJi;_bVf
} 8]O#L}"
)nK+`{;@!
,9ew75Jl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E @Rb+8},"
{ U!RIeC
sSiteURL= sURL; a5d_= :S;
sFilePath = sPath; TV0Y{x*~iH
sFileName = sName; F[F NtZ
this.nSplitter = nSpiltter; 0;*[}M]Z
/q7$"wP
>?G!>kw
} ljz=u;O)
EU'rdG*t/R
g2rH"3sC
public String getSSiteURL() :O?3lj)
{ 6Bexwf<u
return sSiteURL; \yLFV9P}EL
} 7uF @Xh
w !<-e>
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public void setSSiteURL(String value) 9(_n8br1
{ 9#~jlq(
sSiteURL = value; Y`6<:8[?
} Gc5mR9pV
g?Rq .py]!
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public String getSFilePath() hgwS_L
{ <'A-9y]-v
return sFilePath; +Mn(s36f2
} D`.\c#;cN
qw)Ou]L=
$"}*#<Z
public void setSFilePath(String value) IF<T{/MA
{ |%3>i"Y@AK
sFilePath = value; 4$ah~E>,t
} LfCgvq6/pO
&g0r#K
7qWa>fX
public String getSFileName() /#L4ec-'
{ - ku8n%u
return sFileName; yZNg[KH
} o"A?Aq
Fta=yH}
o>m*e7l,
public void setSFileName(String value) U9Q[K`
{ *7#5pT~
sFileName = value; &XXr5ne~C
} L&]{GNw
Imyw-8/;
8|+@A1)&4
public int getNSplitter() LA(/UA3Izd
{ kK0zb{
return nSplitter; 9'|_1Q.b^
} J%!vhQ
9J<vkxG9`
jxYze/I
public void setNSplitter(int nCount) 1,we:rwX
{ cA| n*A-j<
nSplitter = nCount; 3#\C!T0y
} c{x:'@%/s'
} ld5+/"$
gh `_{l
ofgNL .u
/* Y 7?q`
**Utility.java 8k.#4}fP
*/ "tDB[?
package NetFox; r $YEq5
N%=,S?b
9PaV*S(\TR
public class Utility { ldRq:M5z
V~Jt
Tq6\oIBkV
public Utility() e#WASHZN
{ OL@$RTh
{"rL3Lk
gnf4H V~
} U0N6\+
;:Tb_4Hr
//线程睡眠 8\PI1U
public static void sleep(int nSecond) b/E3Kse?
{ *hpS/g/3\
try{ R(f%*S4
Thread.sleep(nSecond); ndk~(ex|j
} wawJZ+V
catch(Exception e) lt\Bm<"z!1
{ 5)->.*G*
e.printStackTrace (); X8~?uroq
} 3 [O+wVv
} f/m0,EERk
uw@-.N^
//日志 fEGnI\
public static void log(String sMsg) Tv|iCYB?
{ {T0Au{88H
System.err.println(sMsg); lj+&3<E
} 'HL.W](
$wl_
)t2eg1a:
public static void log(int sMsg) c;n\HYk
{ Lg-!,Y
System.err.println(sMsg); Q*e\I8R}
} dkQP.Tj$i
} xlc2,L;i
O6">Io5
X2YBZA
/* Ak3V< =gx
**TestMethod.java Qr-,J_
*/ crgVedx~}
package NetFox; UH((d*HX4
i nk!>Z
dChMjaix
public class TestMethod { B& 5Md.h
u!t<2`:h
JC/nHM
public TestMethod() ih: XC
{ ///xx/weblogic60b2_win.exe R\x3'([A5
try{ #f_.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 02YmV%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XXXQAY-,C
SiteFileFetch fileFetch = new SiteFileFetch(bean); vu:] [2"0
fileFetch.start(); m.lzkS]P
} "}S6a?]V
catch(Exception e){e.printStackTrace ();} !';;q
(yB]$
Qn;,OBk
} ghTue*A
O]oH}#5b
N]F}Z#h
public static void main(String[] args) ku#WQL
{ M5N#xgR
new TestMethod(); m@",Zr`f=
} HzsQ`M4cA
} gIKQip<
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