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)); SN|EWe^
} (yE?)s
for(int i=0;i<nEndPos.length-1;i++) XOO!jnQu
{ St&xe_:^<
nEndPos = nStartPos[i+1]; |XxA Fje
} 9Y1&SEsNX
nEndPos[nEndPos.length-1] = nFileLength; ~$>l@> xX
} 9^J8V]X
} nBL7LocvR
~C< X~$y&
;]?1i4p)
//启动子线程 W-%oj.BMA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I#Ay)+D
for(int i=0;i<nStartPos.length;i++) B:5(sK
{ @D8c-`LC"*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :(?joLA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m;{_%oQ;
nStartPos,nEndPos,i); cj-P&D[Ny[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .]%PnJM9K
fileSplitterFetch.start(); qIK"@i[ uq
} I!.o&dk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rd;k>e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R8UtX9'*sa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <3z]d?u
nEndPos = " + nFileLength); AJSe +1
// fileSplitterFetch[nPos.length-1].start(); Lm\N`
PJN TIa
au2ieZZ[
//等待子线程结束 z %` \p
//int count = 0; T%K(opISc(
//是否结束while循环 tfj6#{M5
boolean breakWhile = false; i$)bZr\
&^4\Rx_I
_*6nTSL
while(!bStop) r_T\%
{ 6 k+FTDL
write_nPos(); J&S$F:HM
Utility.sleep(500); O>xGH0H
breakWhile = true; @HJ&"72$<
=6imrRaaV
-,Cx|Nl
for(int i=0;i<nStartPos.length;i++) 9_[TYzpB!
{ 5+b[-Daz
if(!fileSplitterFetch.bDownOver) X>2_Gol!
{ oC>e'_6_b
breakWhile = false; y5iLFR3z
break; }kI-UEn$EP
} on $?c
} /HgdTyR)
if(breakWhile) Adgh:'h
break; Oi&.pY:X-
!7@IWz(,"
qyv9]Q1
//count++; %d*k3f }
//if(count>4) mq$'\c 9.
// siteStop(); 0/S|P1!b
} }N(-e$88
uQWJ7Xm
vGO-a2Z
System.err.println("文件下载结束！"); EsXCi2]1
} D4<nS<8
catch(Exception e){e.printStackTrace ();} Bp6jF2
} v9INZ1# v
x)l}d3
g}0}$WgH:
//获得文件长度 !!4_x
public long getFileSize() x;S v&
{ bgGd
int nFileLength = -1; jI(~\`
try{ r9'lFj
URL url = new URL(siteInfoBean.getSSiteURL()); (%"M% Qko
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P0S;aE
httpConnection.setRequestProperty("User-Agent","NetFox"); rA&|!1q"B
mf6?8!O}>
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int responseCode=httpConnection.getResponseCode(); /8@JWK^I{
if(responseCode>=400) X0J@c "%0
{ a \B<(R.
processErrorCode(responseCode); e~=fo#*2?@
return -2; //-2 represent access is error q.FgX
} 0e9W>J9
/]2-I_WB
16)@<7b]J
String sHeader; |_8::kir:
zg2A$Fd[j
bwUsE U 0
for(int i=1;;i++) xi8RE@gm
{ P!:Y<p{=>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `%p}.X
//Utility.log(in.readLine()); &K2[>5 mG
sHeader=httpConnection.getHeaderFieldKey(i); } WY7!Y
if(sHeader!=null) PcC9)x
{ p>h B&h
if(sHeader.equals("Content-Length")) DtG><g}[]
{ |1X^@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &\4AvaeA8y
break; R<lj$_72Q
} 0*YLFqN
} ?Q;8D@
else zz 7m\
break; Kc_QxON4
} YOwo\'|=
} :M9'wg
catch(IOException e){e.printStackTrace ();} KG)7hja<6g
catch(Exception e){e.printStackTrace ();} UOSa`TZbZ
."l@aE=|
'W usEME
Utility.log(nFileLength); sh[Yu
7g}4gX's
FYR%>Em
return nFileLength; j!GJ$yd=-6
} a{^[<
HiCNs;t
o{pQDI {R
//保存下载信息（文件指针位置） eG9tn{
private void write_nPos() HE(|x1C)j
{ ]S<eO6z
try{ wQWokpP;T7
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4_3Jpz*
output.writeInt(nStartPos.length); > xkl7D
for(int i=0;i<nStartPos.length;i++) ^%-$8sV
{ 5t#+UR
// output.writeLong(nPos); su/l'p'
output.writeLong(fileSplitterFetch.nStartPos); )Y}t~ Zfx
output.writeLong(fileSplitterFetch.nEndPos); SLpB$puS
} $r*7)/
output.close(); LOpnPH`
} csz/[*
catch(IOException e){e.printStackTrace ();} HGfV2FtTz
catch(Exception e){e.printStackTrace ();} 6 /gh_'&
} ]]`hnzJX
DxR__
&H$ 3`"p5u
//读取保存的下载信息（文件指针位置） c-3AzB#[
private void read_nPos() R}c,ahd
{ DvHcT]l>5
try{ ^;@q^b)ZP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9KRHo%m
int nCount = input.readInt(); TKj8a(R_
nStartPos = new long[nCount]; K,bv\j;f
nEndPos = new long[nCount]; UhYeyT
for(int i=0;i<nStartPos.length;i++) U(3+*'8r,1
{ /+pbO-rW*
nStartPos = input.readLong(); uFOxb}a9v
nEndPos = input.readLong(); a'U7 t
} =`[08
input.close(); ^5j|
} mv|eEz)r
catch(IOException e){e.printStackTrace ();} e p~3e5
catch(Exception e){e.printStackTrace ();} V$%%nG uE
} Pj>r(Cv
N ncur]
B~QX{
private void processErrorCode(int nErrorCode) i<&*f}='
{ 7YsBwo
System.err.println("Error Code : " + nErrorCode); >Lp^QP1gU
} %l%5Q;t
-hj@^Auf
#Mw|h^Wm
//停止文件下载 u"XqWLTV
public void siteStop() xr+K: bw
{ |F[E h ~
bStop = true; Vd~{SS2>
for(int i=0;i<nStartPos.length;i++) GY,l&.&
fileSplitterFetch.splitterStop(); ]J+}WR
T#xCu|5
k v1q\
} ,IoPK!5xy
} T{3C3EE?]
//负责部分文件的抓取 hX?L/yf
**FileSplitterFetch.java !cPiH6eO
*/ ps=jGh[
package NetFox; < gB>j\:
h\".TySz
lb ol+O65
import java.io.*; 7;RhA5M
import java.net.*; 8 P85qa@w
,}2yxo;i
H$TYp
public class FileSplitterFetch extends Thread { 0KO_bF#EB=
*c4uCI:0t
rTYDa3
String sURL; //File URL sc'QNhrW
long nStartPos; //File Snippet Start Position QLrFAV
long nEndPos; //File Snippet End Position Wc [@,
int nThreadID; //Thread's ID 4of3#M
boolean bDownOver = false; //Downing is over Ac;rMwXk#
boolean bStop = false; //Stop identical qOYCQ
FileAccessI fileAccessI = null; //File Access interface R+k-mbvnt
vKN"o* q
H6(kxpOI\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s8Kf$E^?e.
{ 'b#RfF,7H}
this.sURL = sURL; 7|LJwXQ-
this.nStartPos = nStart; qawb9Iud0
this.nEndPos = nEnd; XlIRedZ{
nThreadID = id; .r[b!o^VR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P.Pw.[:3
} =KqcWN3k
uqwB`<>KJ
fmZ5rmw!
public void run() P5/K?I~/So
{ 7sKN`
while(nStartPos < nEndPos && !bStop) $s<,xY 9
{ &}wrN(?w
J.Mj76\_
So; ;
try{ hO^8CA,5
URL url = new URL(sURL); nD6mLNi%a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CY;ML6c@
httpConnection.setRequestProperty("User-Agent","NetFox"); d2lOx|jt
String sProperty = "bytes="+nStartPos+"-"; 4<._)_m
httpConnection.setRequestProperty("RANGE",sProperty); oR (hL4Dc
Utility.log(sProperty); RaT(^b(
n B4)%
y;Xb."e~
InputStream input = httpConnection.getInputStream(); sPY*2B
//logResponseHead(httpConnection); ofbNg_K>
@/h_v#W
S6-)N(3|
byte[] b = new byte[1024]; s\QhCS
int nRead; RK?b/9y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lxoc.KDtR
{ cAq>|^f0a
nStartPos += fileAccessI.write(b,0,nRead); 2GOQ|Z
//if(nThreadID == 1) &09z`*,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }@MOkj
} >!O3 jb k
Q!K@
pFi.?|6"
Utility.log("Thread " + nThreadID + " is over!"); & V:q}Q
bDownOver = true; Y: &?xR
//nPos = fileAccessI.write (b,0,nRead); [^xLK
} xcdy/J&
catch(Exception e){e.printStackTrace ();} #- $?2?2
} nN" Y~W^k
} <,p|3p3
3qOq:ZkQ
(7BG~T
//打印回应的头信息 qS<a5`EA
public void logResponseHead(HttpURLConnection con) mqgA
{ 0VC8'6S_k
for(int i=1;;i++) owL>w
{ ry9%Y3
String header=con.getHeaderFieldKey(i); ~qQSt%
if(header!=null) 58\rl G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v#*9rNEj0
Utility.log(header+" : "+con.getHeaderField(header)); WNSf$D{p
else ETvn$ Jdp
break; %,f|H :+>u
} RM\it"g
} h(]aP<49L
Dyv 6K_,
v}p'vh^8B
public void splitterStop() h|OqM:J;
{ +c4]}9f!
bStop = true; N*z_rZE
} ']1\nJP[=X
?"f\"N
q<(yNqMKP
} K];`
j`jF{k b
!4-B xeNY\
/* 3wZA,Z
**FileAccess.java HqNM31)
*//文件访问(定位，写) g a|RW0
package NetFox; 3YT>3f!\
import java.io.*; 'o=`1I
;u`zZb=,[
JJ@O5
public class FileAccessI implements Serializable{ A41*4!L=
eh_{-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $YuVM
RandomAccessFile oSavedFile; c{4C4'GD
long nPos; D?;8bI%"
2)}ic2]pn
g]au|$L4
public FileAccessI() throws IOException P 1`X<A
{ z5G<h
this("",0); <)n8lIK
} #\9sCnb
#T<<{ RA
S1oRMd)r
public FileAccessI(String sName,long nPos) throws IOException vi?{H*H4c
{ =^ur@E
oSavedFile = new RandomAccessFile(sName,"rw"); :m*r(i3
this.nPos = nPos; k(l
oSavedFile.seek(nPos); &?L K>QV
} )>,; GVu"
.ko8`J%%M
1_JtD|Jy
public synchronized int write(byte[] b,int nStart,int nLen) df@IC@`pB
{ fNb2>1
int n = -1; heQ<%NIA"
try{ N-* ^V^V
oSavedFile.write(b,nStart,nLen); )IUeWR
n = nLen; vg@kPuOiO
} uNnx i
catch(IOException e) L3[r7 b
{ [/_M!&zz2
e.printStackTrace (); H^y%Bi&^
} ;/gH6Z?
!ceT>i90h
5Y<O
return n; ]BAM _
} (p4|,\+
9_yO6)`
pw;
} "fWAp*nI3t
`I*W}5
/)I:Cz/f
/* CZ2&9Vb9I
**SiteInfoBean.java S!!i
*/ EHpIbj;n
package NetFox; qMy>:,)Z
vbT"}+^Sh
-*q:B[d
public class SiteInfoBean { \hGoD
^rF{%1DT
cp@(y$
private String sSiteURL; //Site's URL L~F"
private String sFilePath; //Saved File's Path OO)m{5r,{
private String sFileName; //Saved File's Name E.*TJ
private int nSplitter; //Count of Splited Downloading File 6zuWG0t
E/x2LYH
EC[2rROn\
public SiteInfoBean() GilaON*pK.
{//nSplitter的缺省值为5 y&8' V\
//default value of nSplitter is 5 Rou$`<{H
this("","","",5); EOqvu=$6
} T\;7'
#1-y[w/
Q'?{_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [UO?L2$&
{ aH@Ux?-}
sSiteURL= sURL; 1&{]jG{#
sFilePath = sPath; ;3ZHm*xJx
sFileName = sName; Y{c_5YYf
this.nSplitter = nSpiltter; zY?GO"U"
W)WL1@!Z
cEkf9:_La
} qs\O(K8
A2Je*Gz
29:1crzx~
public String getSSiteURL() }T<[JXh=J
{ );4lM%]eb
return sSiteURL; r>v_NKS]t
} eq^<5 f
_TF\y@hF*D
Fa
public void setSSiteURL(String value) $nR1AOm}.B
{ qmzg68
sSiteURL = value; h\+U+?u
} r!/=Iy@
py9zDWk~
R@lmX%Z1
public String getSFilePath() 4VtI8f!
{ UhQsT^b_
return sFilePath; {(mT,}`4
} rn1^6qy)
G2#={g{
/_Z--s>j
public void setSFilePath(String value) HsA4NRF'7
{ u\~dsD2)q
sFilePath = value; H|a9};pO\
} 5|l&` fv`
5DgfrX
|7@[+
public String getSFileName() 88fH!6b
{ Az+}[t
return sFileName; INca
} p-]vf$u
&\(p<TF
W/*2I3a
public void setSFileName(String value) ~jK'n4
{ u,<#z0R|;$
sFileName = value; weMC9T)B
} ~*-(_<FH
i:ar{ q
:W'Yt9v)
public int getNSplitter() J23Tst#s
{ X+l&MD
return nSplitter; sGx"ja+
} xyGk\= S
rLMjN#`^
<DG=qP6O
public void setNSplitter(int nCount) VgfA&?4[
{ anwMG0
nSplitter = nCount; .+1.??8:+
} sflH{!;p
} 0fgt2gA33
ZA4NVt.yN
jq6BwUN
/* Ap}^6_YXd
**Utility.java Lf+M +^l
*/ md`PRZzj@
package NetFox; 0(A(Vb5J.T
y%.^| G
an+`>}]F
public class Utility { lq2P10j@
A%H"a+
ICSi<V[y1
public Utility() $$E!u}
{ 2{!o"6t
[t^Z2a{
H8[L:VeNT
} Fb#_(I[aj
wLeP;u1
//线程睡眠 NYwE=b~I
public static void sleep(int nSecond) Gc=#
{ .ztO._J7f
try{ ]^HlI4 z
Thread.sleep(nSecond); hL:n9G
} [a~|{~?8
catch(Exception e) IY$H M3t7
{ ]IQTf5n
e.printStackTrace (); xA|72!zk0P
} N*.JQvbnr
} zZ3Ko3L%g_
YGVj$\
//日志 NP%Y\%;l6
public static void log(String sMsg) |G.|ocj;
{ BElVkb
System.err.println(sMsg); LfD70r\
} YXCfP~i
Y\!* c=@k
=,B44:`r
public static void log(int sMsg) JGH;&UYP
{ qsnZ?hXPp
System.err.println(sMsg); -h&AO\*^W
} >;Er[Rywr
} B4k~~;|
`9;:mR $
^6=y4t=%F
/* Y*-#yG9
**TestMethod.java H.sHXuu
*/ JTuU}nm+
package NetFox; {"<D$*K~
vu^ '+ky
@dimZsi1
public class TestMethod { . IBy'
Ii"h:GY;\
)l}Gwd]h
public TestMethod() BM+v,hGY
{ ///xx/weblogic60b2_win.exe 'UGkL;
try{ _hgu:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sqkk4w1#C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h$`P|#V&
SiteFileFetch fileFetch = new SiteFileFetch(bean); -nP y?>p"|
fileFetch.start(); AS[yNCsjC
} p<#WueR[
catch(Exception e){e.printStackTrace ();} 5 rpX"(
feOX]g#
qx3@]9
} $[5S M>e]
b,]QfC
2y/|/IW=
public static void main(String[] args) eh=.Q<N
{ HyKvDJ 3_
new TestMethod(); "F nH>g-
} }G,PUjg_^3
} sJ{S(wpi"
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