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)); X'<xw
} ;C%EF
for(int i=0;i<nEndPos.length-1;i++) 1C{n\_hR
{ i&KODhMpP
nEndPos = nStartPos[i+1]; fZC,%p
} e^TF.D?RS
nEndPos[nEndPos.length-1] = nFileLength; }vIm C [
} 4vphLAm
} Y'9deX+
t=#)3C`Q}
I 3PnyNZ
//启动子线程 PHkvt!uH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Cz%ih#^b
for(int i=0;i<nStartPos.length;i++) 71InYIed
{ $G[##j2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), he#iWD'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C/=ZNl9"fn
nStartPos,nEndPos,i); L`v,:#Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q)X&S*-<o~
fileSplitterFetch.start(); w93,N+es6
} *yx:nwmo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FqfeH_-U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sz&`=x#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cA kw5}P
nEndPos = " + nFileLength); 4(]k=c1<
// fileSplitterFetch[nPos.length-1].start(); @U5o;X!qU
&[uGfm+@
=v-D}eJQ=
//等待子线程结束 q6dq@
//int count = 0; h?sh#j6
//是否结束while循环 c-F&4V
boolean breakWhile = false; 4m:E:zVn
vbp)/I-h
)C[8#Q-:
while(!bStop) +]X^bB[
{ yI)2:Ca*
write_nPos(); U<x3=P
Utility.sleep(500); RD^o&VXO
breakWhile = true; 2#!D"F
9^n ]qg^
pFh2@O
for(int i=0;i<nStartPos.length;i++) ~p.23G]x
{ R\^tr
if(!fileSplitterFetch.bDownOver) LCtm@oN
{ Ue7~rPdlR
breakWhile = false; '4iu0ie>D
break; c<=1,TB"-_
} 'E9jv4E$n
} i \~4W$4I
if(breakWhile) !VW#hc\A5
break; ?`xId;}J#7
R0>L[1o
'@FKgy;B)-
//count++; BshS@"8r
//if(count>4) XcXd7e
// siteStop(); rlq8J/0/+
} .dV!du
O;~1M3Ii
*7ox_ R@
System.err.println("文件下载结束！"); tF4"28"h
} N.]8qzW
catch(Exception e){e.printStackTrace ();} =B\?(
} ZHT.+X:_
xAI<<[-
<}evOw2
//获得文件长度 /T?['#:r-)
public long getFileSize() hikun2
{ ji "*=i
int nFileLength = -1; lPH]fWt<
try{ *m2:iChY
URL url = new URL(siteInfoBean.getSSiteURL()); {r"HR%*u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `k+k&t
httpConnection.setRequestProperty("User-Agent","NetFox"); y(HR1vQ;Z
e>[QF+e)y
%}@^[E)
int responseCode=httpConnection.getResponseCode(); &\A$Rj)
if(responseCode>=400) F[lHG,g-
{ ?w.Yx$Z"
processErrorCode(responseCode); : v]< h
return -2; //-2 represent access is error 6i%)'dl
} _$\T;m>'A
?@ O[$9y
z;-2xD0&U[
String sHeader; P_9O8"W
KF.?b]
$ysC)5q.
for(int i=1;;i++) iVD9MHT4
{ ;fuy}q8@7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !e?\> '
//Utility.log(in.readLine()); E @7! :
sHeader=httpConnection.getHeaderFieldKey(i); u{si
if(sHeader!=null) &{$\]sv
{ {d)+a$qj
if(sHeader.equals("Content-Length")) H='`#l1
{ B;EdLs}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +f+\uObi:
break; 1:-$mt_*
} +m"iJW0
} QDU^yVa_
else 7%X$6N-X
break; #/n\C
} |XQ!xFB
} '1d-N[
catch(IOException e){e.printStackTrace ();} P/27+5(|
catch(Exception e){e.printStackTrace ();} !=a8^CV
Es?~Dd
$]O\Ryf6
Utility.log(nFileLength); :g Ze>
&.d~ M1Mz
aFLm,
return nFileLength; %;gD_H4mm
} R\iU)QP
U!('`TYe
2rA`y8g(L
//保存下载信息（文件指针位置） h4V.$e<T&
private void write_nPos() c|E
{ k1X<jC]P
try{ )+{'p0
output = new DataOutputStream(new FileOutputStream(tmpFile)); C; ! )<(Vw
output.writeInt(nStartPos.length); |XeuqZa
for(int i=0;i<nStartPos.length;i++) zdr?1=
{ 7.]ZD`"Bb
// output.writeLong(nPos); gbF.Q7?$u
output.writeLong(fileSplitterFetch.nStartPos); JTVCaL3Z
output.writeLong(fileSplitterFetch.nEndPos); tL D.e
} *F=wMWa
output.close(); 2Ddrxc>48
} hF6EOCY6D
catch(IOException e){e.printStackTrace ();} )4j#gHN\
catch(Exception e){e.printStackTrace ();} &0M^UvO
} 98x(2fCvF(
WFtxEIrl3j
GX\/2P7CZ
//读取保存的下载信息（文件指针位置） " 4s,a
private void read_nPos() (d_{+O"
{ _,5(HETE2
try{ U:ZklDW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #\w~(Nm-
int nCount = input.readInt(); Rf7py)
nStartPos = new long[nCount]; ^}9Aq $R
nEndPos = new long[nCount]; [~ fJ/
for(int i=0;i<nStartPos.length;i++) Ucv-}oa-?
{ HZR~r:_ i
nStartPos = input.readLong(); NX$$4<A1
nEndPos = input.readLong(); \s[Uq
} F`f#gpQ
input.close(); R7+k=DI
} UAa2oY&
catch(IOException e){e.printStackTrace ();} 2uz<n}IV
catch(Exception e){e.printStackTrace ();} yt$V<8a
} UA}k"uM
d!!5'/tmS
u"tv6Qp
private void processErrorCode(int nErrorCode) A2]N :=
{ "#(]{MY
System.err.println("Error Code : " + nErrorCode); IS"UBJ6p
} Yk[yG;W
9;kWuP>k4u
)'92{-A0
//停止文件下载 (eHvp
public void siteStop() <Cm:4)~
{ )t0t*xu#
bStop = true; IeE+h-3p
for(int i=0;i<nStartPos.length;i++) eo"6 \3z
fileSplitterFetch.splitterStop(); l1a=r:WhH
~,.Agx
TR|G4l?
} % `\8z
} J7$5<
//负责部分文件的抓取 RytQNwv3
**FileSplitterFetch.java qd"*Td
*/ P5kkaLzG
package NetFox; db4Ol=
LKtr>u
pz~AsF
import java.io.*; UEt#;e
import java.net.*; g;Bq#/w
#NwlKZ-
9w(QM-u
public class FileSplitterFetch extends Thread { Rax}r
3%>"|Ye}A
^<7)w2ns
String sURL; //File URL {6*h';~
long nStartPos; //File Snippet Start Position uG~%/7Qt{
long nEndPos; //File Snippet End Position L3'o2@$
int nThreadID; //Thread's ID 5YJLR;
boolean bDownOver = false; //Downing is over Lr_+)l
boolean bStop = false; //Stop identical @zW'!Ol
FileAccessI fileAccessI = null; //File Access interface d2Bn`VI
1P@&xcvS\
J8~3LE )G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WADNr8.
{ g.Z>9(>;Y
this.sURL = sURL; eLM_?9AZ!R
this.nStartPos = nStart; 0(h *<g:
this.nEndPos = nEnd; E XEae?
nThreadID = id; Xb5n;=)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h{VCx#!]
} bo`w(h_
Fn yA;,*
#P<v[O/rA
public void run() JEGcZeq)
{ \@3i=!
while(nStartPos < nEndPos && !bStop) +kmPQdO;*/
{ x/R|i%u-s
+(QGlRd
-%NT)o
try{ ma?$@]`k
URL url = new URL(sURL); r. =_=V/t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }2-{4JIq}
httpConnection.setRequestProperty("User-Agent","NetFox"); 2>_6b>9]
String sProperty = "bytes="+nStartPos+"-"; 7JQ5OC3
httpConnection.setRequestProperty("RANGE",sProperty); UXnd~DA
Utility.log(sProperty); z{7&=$
Y6,< j|
p(:\)HP)R
InputStream input = httpConnection.getInputStream(); 8(\Az5%
//logResponseHead(httpConnection); [89#8|+
(Rve<n6{A
; P&Ka
byte[] b = new byte[1024]; W:ih#YW_F
int nRead; %DbL|;z1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y!h$Z6.
{ g< M\zD
nStartPos += fileAccessI.write(b,0,nRead); l!EfvqWX
//if(nThreadID == 1) ,0[bzk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S9t_2%e
} 1BmevEa)
cL7je
p9y "0A|
Utility.log("Thread " + nThreadID + " is over!"); {|O8)bW'
bDownOver = true; YO|Kc {j2e
//nPos = fileAccessI.write (b,0,nRead); % Lhpj[C
} dc|"34;^"
catch(Exception e){e.printStackTrace ();} T4F}MVK
} k^:$ETW2 D
} j]6Z*AxQ
&Ru|L.G`
4t|ril``]
//打印回应的头信息 Eo!1 WRruF
public void logResponseHead(HttpURLConnection con) e%afK@c
{ tK`sVsm>
for(int i=1;;i++) .R#p<"$I
{ j*Ta?'*
String header=con.getHeaderFieldKey(i); lc,{0$ 1<
if(header!=null) ={o>g'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s=! y%
Utility.log(header+" : "+con.getHeaderField(header)); 'p80X^g
else 7%c9 nY
break; \f}S Hh
} &HNJ'
} wWKC.N
><mZOTn e;
TxoMCN?7c
public void splitterStop() be|k"s|6)
{ xa[<k>r3
bStop = true; $6Lgaz
} &.y:QVR,!
BuCU_/H
0m(/hK
} rUvqAfE&+
Xp[[ xV|
eu@-v"=w
/* O5CIK}A
**FileAccess.java L=O,OS+
*//文件访问(定位，写) Cg?D<l4
package NetFox; #'^!@+)
import java.io.*; tV<}!~0,*
tO~DA>R
I,(m\NalK
public class FileAccessI implements Serializable{ 7hZCh,O
@NWjYHM[`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2`Ub;Nn29
RandomAccessFile oSavedFile; 4_TxFulX.
long nPos; WO?EzQ ?
s#/JMvQ#
s^TF+d?B
public FileAccessI() throws IOException \rY|l
{ iNUisl
this("",0); q(M[ij
} CkE@Ll3Z
9$c0<~B\
P%z\^\p"5
public FileAccessI(String sName,long nPos) throws IOException T^B&GgW
{ p+SFeUp
oSavedFile = new RandomAccessFile(sName,"rw"); }L^Yoq]
this.nPos = nPos; IsxPm9P2<
oSavedFile.seek(nPos); (cAv :EKpo
} +Pd&YfU9
_A|1_^[G(
z6#N f,
public synchronized int write(byte[] b,int nStart,int nLen) eS8tsI
{ ,>A9OTSN\
int n = -1; TviC1 {2
try{ ]:(>r&'
oSavedFile.write(b,nStart,nLen); :WIbjI=
n = nLen; !MSz%QcO
} =unMgX]$
catch(IOException e) M7-piRnd4
{ <"{Lv)4
e.printStackTrace (); aR6?+`6<
} O@{ JB
BQ{Gp 2N
S}gUz9ks
return n; mf=,6fx28
} =K I4
RXh0hD
k!H;(B"s-
} /6B!&b2f
@a#qq`b;
VQ5T$,&
/* v|t_kNX;v*
**SiteInfoBean.java WCA`34(
*/ /Mb?dVwA
package NetFox; O6LZ<}oUR
&&4av*\I
zYO+;;*@
public class SiteInfoBean { E]WammX c
N3g[,BE
fIN8::Cs[
private String sSiteURL; //Site's URL XL c&7
private String sFilePath; //Saved File's Path M>P-0IC
private String sFileName; //Saved File's Name ;ZPAnd:pb
private int nSplitter; //Count of Splited Downloading File .%_scNP
$%ZEP>]
X&nkc/erx
public SiteInfoBean() 5|f[evQj<S
{//nSplitter的缺省值为5 O|m-Uz"+
//default value of nSplitter is 5 3.U5Each-
this("","","",5); zB/$*Hd
} sJg-FVe2
uy)iB'st&
>DVjO9Kf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9_V'P]@
{ ..V6U"/
sSiteURL= sURL; ]Cnj=\'
sFilePath = sPath; #x$.
sFileName = sName; o)F^0t
this.nSplitter = nSpiltter; 8~AO~
$J"}7+
jo{[*]Oa
} ~j}di^<{
dy N`9
P$S>=*`n U
public String getSSiteURL() 6f,#O8]#5
{ u:&gp
return sSiteURL; Yf&x]<rkCp
} ,+<NP}Yg#G
pm$,B7Q`oO
z #c)Q
public void setSSiteURL(String value) 3ddH@Y|
{ TzmoyY
sSiteURL = value; = q9>~E{}
} LL|$M;S
mG@xehH
b<};"H0a
public String getSFilePath() e#JJd=
{ W4Rs9NA}
return sFilePath; 9Slx.9f
} -'3~Y 2#
Zm,<2BP>
/>c F
public void setSFilePath(String value) 8X!^ 2B}J
{ 'hfQ4EN
sFilePath = value; ]f#ZU{A'mt
} -8;U1^#
<iVn!P
fiqeXE?E
public String getSFileName() S{gB~W
{ ax0RtqtR&
return sFileName; :pj#t$:!
} \E1[ /
7y.$'<
NBZFIFO<
public void setSFileName(String value) -:b0fKn
{ H(9%SP@[c
sFileName = value; GhpVi<FL
} ' _Ij9{M
ukb2[mb*u
+LeZjA[
public int getNSplitter() @N,dA#
{ ]+\;pb}bq
return nSplitter; ~6L\9B)
} z}&w7O#
:5IbOpVM
PrqN5ND
public void setNSplitter(int nCount) 4<g,L;pUU
{ .<566g}VP
nSplitter = nCount; BC0SSR@e
} oV"#1lp*
} l\<*9m<
:"5'l>la
|LA@guN
/* D_er(
**Utility.java rKg~H=4x2
*/ .si!`?K%[
package NetFox; 0J7)UqMf.
,pL%,>R5
,paD/
public class Utility { L]I ;{Y
r(-`b8ZE
0mk-o
public Utility() %K[_;8
{ I:M]#aFD
6qg_&woJ3
w&<-pIa`
} Xr'Y[E[
AX3iB1):K
//线程睡眠 !\w@b`Iv8
public static void sleep(int nSecond) I?c "\Fe
{ kSj,Pl\NC
try{ ?EQ]f34
Thread.sleep(nSecond); EwDFUK
} V9\g?w
catch(Exception e) Z9TmX A@
{ 9NXf~-V-
e.printStackTrace (); L:UJur%
} j6<o,0P
} [yj-4v%u`
gI<e=|J6w
//日志 -DD2
public static void log(String sMsg) /NRdBN
{ L-Qc[L
System.err.println(sMsg); s/#L?[YH
} j_L1KB*
C3 >X1nU
^y:!=nX^
public static void log(int sMsg) 1t7vP;
{ l]tda(
System.err.println(sMsg); CqHCJ '
} p2T<nP<Pt
} 5n,?&+*L
USBU?WDt
t* eZe`|
/* rC )pCC
**TestMethod.java /4x3dwXW@
*/ > Q[L,I
package NetFox; $M%<i~VXe&
W~(4t:hp
( -^-
public class TestMethod { b {fZU?o
1=Npq=d
+pDZ,c,
public TestMethod() K??(>0Qr}r
{ ///xx/weblogic60b2_win.exe n:QFwwQ`Q;
try{ kB~KC-&O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cTlitf9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o[<lTsw<
SiteFileFetch fileFetch = new SiteFileFetch(bean); tx0`#x
fileFetch.start(); 9?M>Y?4
} ]M2<b:yo
catch(Exception e){e.printStackTrace ();} }EFMJ,NQ
q6E8^7RtS@
7bcl^~lY
} ,c3gW2E
^\|Hz\"*
tR`'( *wh
public static void main(String[] args) x@^Kd*fo
{ OJX* :Q
new TestMethod(); "h.-qQGU%
} B,rpc\_
} "p,TYjT?R
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