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)); :#htOsP
} Qr-J-2s?B
for(int i=0;i<nEndPos.length-1;i++) 7-g4S]r<
{ +9F#~{v`4a
nEndPos = nStartPos[i+1]; p[cL#fBz
} >!F,y3"5S
nEndPos[nEndPos.length-1] = nFileLength; RGuHXf
} j3-6WUO
} ;fME4Sp
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K0H!Ds9
//启动子线程 YaT+BRh?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'wnY>hN
for(int i=0;i<nStartPos.length;i++) "?&bh@P&
{ F1*rUsRKN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #TwE??ms
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &u\z T P
nStartPos,nEndPos,i); RW^v{'o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CuO*>g^K[
fileSplitterFetch.start(); UKQ&TV}0
} CvWEXY_P2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?q}wl\"8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JJ=is}S|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "{"2h>o#D}
nEndPos = " + nFileLength); ZboJszNb;
// fileSplitterFetch[nPos.length-1].start(); ^J~4~!
m$qC 8z]
?JTyNg4<
//等待子线程结束 .FRF<_`^
//int count = 0; fqsp1m$
//是否结束while循环 Cj\+u\U#
boolean breakWhile = false; PR6uw
i8@e}O I
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while(!bStop) <FT\u{9$
{ #$C]0]|
write_nPos(); q=i<vcw
Utility.sleep(500); LK/V]YG
breakWhile = true; R+hS;F nh%
q$'&RG
(jFE{M$-
for(int i=0;i<nStartPos.length;i++) lj*913aFh
{ m1i$>9,
if(!fileSplitterFetch.bDownOver) c} ET#2,
{ cNc_ n<M
breakWhile = false; dk`!UtNNRa
break; j|dzd<kE6
} IqKXFORiNI
} '[8jm=Q#'
if(breakWhile) [4rMUS7-m"
break; tvxcd*{
F+S#m3X
#e269FwN
//count++; /O9EI'40)
//if(count>4) E'6P>6l5
// siteStop(); lS-i9U/,>
} =U`c }dhS
>g0@ Bk
'X<uG x
System.err.println("文件下载结束！"); &YKzK)@
} me^Gk/`Em
catch(Exception e){e.printStackTrace ();} Vho0f<`E
} =8_TOvSJ4p
vqZM89xY
<yO9j
//获得文件长度 *sVxjZvV
public long getFileSize() }0),b ?*e
{ (HKm2JuFG
int nFileLength = -1; f(o`=% k8
try{ 6WM_V9Tidq
URL url = new URL(siteInfoBean.getSSiteURL()); JjML!;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A|Gqjy^;@
httpConnection.setRequestProperty("User-Agent","NetFox"); o?+e_n=
&\[J
EQO7:vb
int responseCode=httpConnection.getResponseCode(); *3($s_r>
if(responseCode>=400) 1M+!cX
{ (1]@ fCd +
processErrorCode(responseCode); @Qozud\?
return -2; //-2 represent access is error {_}"USS
} J"|$V#
8}T3Fig,q
bkIA:2HX
String sHeader; EA#!h'-s
(oEA)yc|
L$Z_j()2
for(int i=1;;i++) p:%E>K1<
{ ^ ?9 ~R"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ! NEq|Y
//Utility.log(in.readLine()); 5]%kWV>
sHeader=httpConnection.getHeaderFieldKey(i); %&(\dt&R1h
if(sHeader!=null) '#6DI"vJ
{ $,42h
if(sHeader.equals("Content-Length")) kA`qExw%
{ d^^>3L!h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LnX^*;P5t
break; -;z\BW5y
} dUSuhT
} T/5UlW|\
else U6PUt'Kk@
break; '|R|7nQAj
} S3cQC`^
} ~zRd||qv
catch(IOException e){e.printStackTrace ();} {qyo#
catch(Exception e){e.printStackTrace ();} 8!Kfe
N6'Y N10
1+iiiVbMH
Utility.log(nFileLength); 0X w?}
R!CUR~F
v*v&f!Ym&s
return nFileLength; UU`qI}Ys8F
} ]F!h~>
w2GY,,R
Ta$<#wb
//保存下载信息（文件指针位置） I9m
private void write_nPos() 2&#iHv
{ 30"G%DFd
try{ o\[nGf C&
output = new DataOutputStream(new FileOutputStream(tmpFile)); `#F>?g$2
output.writeInt(nStartPos.length); uESHTX/[
for(int i=0;i<nStartPos.length;i++) b\mN^P~>A
{ |lY8u~%
// output.writeLong(nPos); -tZb\4kh
output.writeLong(fileSplitterFetch.nStartPos); AWcPOU
output.writeLong(fileSplitterFetch.nEndPos); #*@Yil=1
} '"a8<7
output.close(); ,3u19>2
} dtm@G|Ij
catch(IOException e){e.printStackTrace ();} me" <+6
catch(Exception e){e.printStackTrace ();} {S!~pn&^Y
} T^t`Hp
q9^r2OO
Ye\%o[X
//读取保存的下载信息（文件指针位置） 0"Hf6xz
private void read_nPos() %## bg<
{ ;d:7\
try{ %l,EA#89s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d"a`?+(Q
int nCount = input.readInt(); &#.&xc2sRZ
nStartPos = new long[nCount]; j!pxG5%
nEndPos = new long[nCount]; T^W8_rm*3
for(int i=0;i<nStartPos.length;i++) &bb*~W-
{ ga1RMRu+
nStartPos = input.readLong(); EIAT*l:NW
nEndPos = input.readLong(); J u7AxTf~
} [gDvAtTZ5
input.close(); /hHD\+0({
} O.!?O(
catch(IOException e){e.printStackTrace ();} '|.u*M,b
catch(Exception e){e.printStackTrace ();} Zzs pE}
} DlP=R
'_8Vay~
xhv)rhu@
private void processErrorCode(int nErrorCode) = 8n*%NC
{ ]up:pddIh
System.err.println("Error Code : " + nErrorCode); }Na*jr0y9{
} 'tc$#f^:
O<5bsKw'r
\y=,=;yv
//停止文件下载 mGX;JOjZ
public void siteStop() RV~w+%f
{ zuOIos
bStop = true; %u#pl=k}
for(int i=0;i<nStartPos.length;i++) [69aTl>/
fileSplitterFetch.splitterStop(); 2ZnTT{]_m
}x+{=%~N
&Jj?C
} &p*N8S8
} nt7ui*k
//负责部分文件的抓取 ,PnEDQ|l
**FileSplitterFetch.java l\bBc,%jt
*/ zOcMc{w0
package NetFox; /bVI'fT
}'3V(;9
'del|"h!M
import java.io.*; i/->g:47P
import java.net.*; dM)fr
I".r`$XZ
H7WKnn@
public class FileSplitterFetch extends Thread { t+pI<c^]y
~ohW9Z1
R8axdV9(
String sURL; //File URL q\ ?6-?Mr
long nStartPos; //File Snippet Start Position GXwV>)!x
long nEndPos; //File Snippet End Position "C>KKs }
int nThreadID; //Thread's ID mu*wX'.'
boolean bDownOver = false; //Downing is over UrgvG, Lt
boolean bStop = false; //Stop identical lA{Sr0fTP
FileAccessI fileAccessI = null; //File Access interface Tf+B<B:
&iuc4"'
5dhRuc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F3?v&
{ V&gUxS]*
this.sURL = sURL; R|_?yV[
this.nStartPos = nStart; Qv8Z64#
this.nEndPos = nEnd; {8E hC/=
nThreadID = id; t&*$@0A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |*!I(wm2i
} z\v\T|C
5}1cNp6@
rZ^DiFR
public void run() ,cS|fG
{ >XA#/K
while(nStartPos < nEndPos && !bStop) N3E=t#n
{ . a~J.0co
d6_ CsqV
F3+)bIz
try{ nU/v(lN
URL url = new URL(sURL); zd+8fP/UB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W8\K_M}
httpConnection.setRequestProperty("User-Agent","NetFox"); "8s0~[6S
String sProperty = "bytes="+nStartPos+"-"; Pb!kl #
httpConnection.setRequestProperty("RANGE",sProperty); 98A ;R
Utility.log(sProperty); Zl]\sJ1"
b"p,~{
7Rq;V=2YV
InputStream input = httpConnection.getInputStream(); ($]y*|Obn
//logResponseHead(httpConnection); CfAX,f"ZP
bd9]'
A|jaWZM-
byte[] b = new byte[1024]; /mvuSNk
int nRead; ZNzye1JSm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v50=D/&w
{ afH`<!
nStartPos += fileAccessI.write(b,0,nRead); 7j5l?K-
//if(nThreadID == 1) N[czraFBD}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2rne=L
} UnGG%
7\5;;23N4
=d`,W9D
Utility.log("Thread " + nThreadID + " is over!"); p9Ks=\yvL
bDownOver = true; :o=[Zp~B4d
//nPos = fileAccessI.write (b,0,nRead); C";F's)
} POdG1;)
catch(Exception e){e.printStackTrace ();} 5PG%)xff*
} 8LB+}N(8f
} |eJ4"OPC
M&xfQNE
m>~%. (/x
//打印回应的头信息 *l^h;RSx
public void logResponseHead(HttpURLConnection con) <$_B J2Z
{ ]7Tjt A.\q
for(int i=1;;i++) Wn<3|`c
{ 8 yQjB-,#
String header=con.getHeaderFieldKey(i); 9)'L,Xt4:T
if(header!=null) }h>QkV,{2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AW1691Q
Utility.log(header+" : "+con.getHeaderField(header)); jCxw|tmgq
else q@H?ohIH
break; 3S ,D~L^
} NFv9%$l-
} | x/,
$Ic: c
l}># p'$
public void splitterStop() u-=%gx"Di
{ >#<o7]
bStop = true; fHdPav f,S
} )EcE{!H6+
Ag^Cb'3X
_m#M^<0n
} Yu`b[]W
t L}i%7
Y&'Bl$`
/* Q3*@m
**FileAccess.java !0{":4\
*//文件访问(定位，写) ?dY}xE
package NetFox; 9U^jsb<St>
import java.io.*; aj85vON1`
e}D#vPaSY
*^ g7kCe(
public class FileAccessI implements Serializable{ (%D*S_m'
7g[T#B'/x,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xQ=[0!p+
RandomAccessFile oSavedFile; ^ 1}_VB)^
long nPos; G$<FQDvs
p eQD]v
Tj$D:xKf)
public FileAccessI() throws IOException 2'$p(
{ zVFz}kJa
this("",0); UB|f{7~&
} i!@L`h!rw
J.N%=-8
8HS1^\~(6l
public FileAccessI(String sName,long nPos) throws IOException `9SuDuw;s
{ -Xb]=Yf-
oSavedFile = new RandomAccessFile(sName,"rw"); < {$zOF}
this.nPos = nPos; l1fP@|
oSavedFile.seek(nPos); `D6Bw=7
} p(fYpD
S;[9 hI+
dq?{?~3
public synchronized int write(byte[] b,int nStart,int nLen) T.]+T[}!
{ #p_3j 0S
int n = -1; 4{7O}f
try{ s~W:N.}*
oSavedFile.write(b,nStart,nLen); CA, &R<]
n = nLen; pn<M`,F~q
} x >hnH{~w
catch(IOException e) ep* (
{ )/A IfH
e.printStackTrace (); VC,wQb1J/
} nSdta'6
I'%vN^e^
qc;9{$?xV
return n; BR;f!
} maW,YOyRN
R]L|&{
`Hld#+R
} ;& ny< gQ
M[LjN
z'GYU=
/* xj~5/)XX|X
**SiteInfoBean.java N,6(|,m
*/ $\h\,N$y
package NetFox; zcnp?%
^W+q!pYM9+
="hh=x.5J
public class SiteInfoBean { fS+Ga1CsH
=QXLr+ y@
bq{":[a
private String sSiteURL; //Site's URL %9Br
private String sFilePath; //Saved File's Path E(N?.i-%$
private String sFileName; //Saved File's Name `&xo;Vnc
private int nSplitter; //Count of Splited Downloading File vs}_1o
z'OY6
2YI#J.6]H
public SiteInfoBean() r*CI6yP
{//nSplitter的缺省值为5 AdMA|!|:hc
//default value of nSplitter is 5 9un* 1%
this("","","",5); QhUv(]0
} t4>%<'>e
A82Bn|J
hqOy*!8'@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "5Orj*{
{ %v 0 I;t
sSiteURL= sURL; 6B>1"h%Wf
sFilePath = sPath; -?{bCq
sFileName = sName; szW_cjS
this.nSplitter = nSpiltter; b/65Q&g'
(T+fO}0
WxwSb`U|
} _EMq"\ND
-v"\WmcS
r:Uqtqxh
public String getSSiteURL() /;>U0~K
{ K8xwPoRL
return sSiteURL; G&8)5d[
} KZ_d..l*W
Uv|z c
VQA}!p
public void setSSiteURL(String value) k/[*Wz$W
{ "#Ov!t
sSiteURL = value; ]gI>ay"\QA
} T*YbmI]4
c4Q{
<5rs~
public String getSFilePath() #m yiZL%
{ U^+xCX<
return sFilePath; wc@X:${
} .PjJ g^^
P5 fp!YF
?M?S+@(
public void setSFilePath(String value) "A\.`*6
{ Q(Q.(
sFilePath = value; K6"#&0
} 7u8HcHl
c *<"&
44;ZX$HL
public String getSFileName() yO}RkRA
{ ?S&pq?
return sFileName; m2&"}bI{
} 'wh2787
5m2`$y-nb
f%r0K6p
public void setSFileName(String value) [>+}2-#
{ V^Gz7`^
sFileName = value; ' *hy!f]
} i"|="O0v5
l"9.zPvT<
qbu>YTj
public int getNSplitter() o&M2POI~q
{ 4?Mb>\n%<^
return nSplitter; w D|p'N
} CZE!rpl
v,6
0V{a{>+
public void setNSplitter(int nCount) rzmd`)g
{ (pY'v/a-
nSplitter = nCount; w#V{'{DKp
} nT UKA
} )nJo\HFXv
X;$g7A
0}'
/* <?|v-(E
**Utility.java -"*UICd
*/ :W]IJ mI\
package NetFox; HzADz%~
\;w$"@9
#'"zyidu
public class Utility { F3k]*pk8w
&E98&[`7
L0ZgxG3:g
public Utility() l+# l\q%l
{ BLc&q)
GL4-v[]6I
a`SQcNBf*
} S 6e<2G=O
o80?B~o
//线程睡眠 z=ItKoM*<
public static void sleep(int nSecond) MF+J3)
{ ~lB im$o
try{ Co e q<
Thread.sleep(nSecond); 9Z! j
} a%3V< "f
catch(Exception e) L`"PaIMz
{ G01J1Ll}
e.printStackTrace (); XL@Y!
} 5HWVK.
} \;"$Z9W
Bvbv~7g(
//日志 'EsN{.l?
public static void log(String sMsg) n,KOQI;
{ bj6-0`
System.err.println(sMsg); Ie3 F
} 8J60+2Wa
#ma#oWqF}
+h!OdWD9
public static void log(int sMsg) jVh I`F{n
{ {/f\lS.5g
System.err.println(sMsg); V0'T)
} *Q=3v
} iTb k]$
wSrq?U5q
}(}+I}&~
/* zj G>=2
**TestMethod.java We^!(G
*/ dV{N,;z
package NetFox; Rg/*)SKj
:H}a/ x*ur
D9OI",h
public class TestMethod { "wk~[>
u_0&`zq
&[]0yNG
public TestMethod() Fi8'3/q-^
{ ///xx/weblogic60b2_win.exe `Qzga}`"]
try{ [Xy^M3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Vf Jpiv1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P\"|b\O1
SiteFileFetch fileFetch = new SiteFileFetch(bean); Kv**(~FNnH
fileFetch.start(); WU}?8\?U%
} \Qa6mt2h
catch(Exception e){e.printStackTrace ();} lYZ5FacqC
CuE>=y-"I
_)4YxmK%
} t?[|oz:v
_ZgIm3p0A
GWs[a$|
public static void main(String[] args) x50,4J%J'r
{ WdXi
new TestMethod(); U p1&(
} y1DP`Ro
} f< A@D"m/
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