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)); ]:#=[CH
} r:$tvT*
for(int i=0;i<nEndPos.length-1;i++) \?]U*)B.r
{ )2RRa^=&
nEndPos = nStartPos[i+1]; >t)Pcf|s
} C 2nmSXV
nEndPos[nEndPos.length-1] = nFileLength; {j9TzR
} rbnAC*y8'L
} QK?V^E
r@}`Sw]@
t 86w&
//启动子线程 {N>ju
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `@ YV
for(int i=0;i<nStartPos.length;i++) zwZvKV/g
{ #lrwKHZ+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X+ITW#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cFw-JM<
nStartPos,nEndPos,i); l>K+4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cN0 *<
fileSplitterFetch.start(); 1R3,Z8j'
} 6`O,mpPu4G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ru@#s2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PkrVQH9^w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9:4S[mz/hD
nEndPos = " + nFileLength); w.w{L=p:<"
// fileSplitterFetch[nPos.length-1].start(); $*942. =Q
pdRM%ug
?/OF=C#
//等待子线程结束 ~*7$aj
//int count = 0; 0t?o6e
//是否结束while循环 o3dqsQE%
boolean breakWhile = false; )][U6e
I4G0!"T+
LWv<mtuYf
while(!bStop) b'\Q/;oz>
{ Q3tyK{JE
write_nPos(); y<kUGsD
Utility.sleep(500); &'$Bk5D@G
breakWhile = true; $uHQl#!;
LAlwQ^v|
{/]2~!
for(int i=0;i<nStartPos.length;i++) R|8vdZ%@
{ 6&os`!
if(!fileSplitterFetch.bDownOver) `jGeS[FhR
{ xcr2|
breakWhile = false; GMJ4v S
break; EjLq&QR.
} $KYGQP
} a~7D4G
if(breakWhile) `s)4F~aVo
break; V?j,$LixY
?{qUn8f2
g %mCgP
//count++; )]j3-#
//if(count>4) (DO'iCxlNh
// siteStop(); s{@R|5
} G<e+sDQ2
4W"A*A
\1!Q.V
System.err.println("文件下载结束！"); %`C*8fc&
} BQ0?B*yqd
catch(Exception e){e.printStackTrace ();} -`I|=lBz{H
} Cw+boB_tip
?YW~7zG
9s^$tgH
//获得文件长度 QMBT8x/+_'
public long getFileSize() bFX{|&tHU
{ KkZx6A)$u
int nFileLength = -1; M YF ^zheD
try{ /eQAGFG
URL url = new URL(siteInfoBean.getSSiteURL()); ^wolY0p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S/XU4i:aV
httpConnection.setRequestProperty("User-Agent","NetFox"); aDdGhB
@}Hu)HO
;stuTj@vH
int responseCode=httpConnection.getResponseCode(); Ab ,^y
if(responseCode>=400) +r3)\L{U
{ oIE 1j?
processErrorCode(responseCode); :EV.nD7
return -2; //-2 represent access is error m`-);y
} BuV71/Vb{Q
P`lv_oV
t,7%| {
String sHeader; ww^\_KGu7
hN2A%ds*(j
A0Mjk
for(int i=1;;i++) X(ph$,[
{ tLy:F*1i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VO:4wC"7
//Utility.log(in.readLine()); R'v~:wNTNs
sHeader=httpConnection.getHeaderFieldKey(i); &IQ=M.!r
if(sHeader!=null) uI-T]N:W8x
{ 2|>\A.I|=
if(sHeader.equals("Content-Length")) 9~Dg<wQ
{ z?\it(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m=01V5_
break; lAU99(GXV
} .nD#:86M
} #-;c!<2
else BTkx}KK
break; \P.h;|u
} G]=z ![$
} _Q5mPBO
catch(IOException e){e.printStackTrace ();} ~</FF'Xz
catch(Exception e){e.printStackTrace ();} ,s~l; Gkj
bgorW"'
&'z_:Wm
Utility.log(nFileLength); UTkPA2x
LU:xmDv
|'?vlUCd
return nFileLength; `NW/Z/_
} V.*TOU{{xh
BD C DQ
&zJI~R
//保存下载信息（文件指针位置） P1mg;!tq
private void write_nPos() /]`@.mZ9:
{ U+!RIF[Je
try{ q}P@}TE
output = new DataOutputStream(new FileOutputStream(tmpFile)); J9mK9{#q
output.writeInt(nStartPos.length); <T_3s\
for(int i=0;i<nStartPos.length;i++) bTD?uX!^@
{ cT'Bp)a
// output.writeLong(nPos); XGSFG~d
output.writeLong(fileSplitterFetch.nStartPos); 072C!F
output.writeLong(fileSplitterFetch.nEndPos); C^)Imr
} z By%=)`
output.close(); ;R*-cm
} w jkh*Y
catch(IOException e){e.printStackTrace ();} <<>+z5D+
catch(Exception e){e.printStackTrace ();} aRMlE*yW
} ~n]5iGz
h]oUY.Pf
E'LI0fr
//读取保存的下载信息（文件指针位置） p1KhI;^
private void read_nPos() DU!T#H7
{ '3l TI
try{ fUjo',<s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fB$a)~
int nCount = input.readInt(); E`fG9:6l]
nStartPos = new long[nCount]; Q VTL}AT2:
nEndPos = new long[nCount]; ;_cTrjMv\
for(int i=0;i<nStartPos.length;i++) [inlxJD
{ >-MnB
nStartPos = input.readLong(); N!K%aH~O
nEndPos = input.readLong(); ?J:w,,4m
} <[db)r~c
input.close(); vywB{%p
} B(W~]i
catch(IOException e){e.printStackTrace ();} Uc tlE>X`
catch(Exception e){e.printStackTrace ();} +dCDk* /m
} 0/Q_% :
\jC) ;mk
%OBW/Ti
private void processErrorCode(int nErrorCode) 0<m7:D Gd
{ V+`kB3GV
System.err.println("Error Code : " + nErrorCode); gRY#pRT6d
} << 6GE
'##?PQ*u
A^OwT#
//停止文件下载 c]9gf\WW
public void siteStop() mo| D
{ 5T;LWS
bStop = true; ahl|N`
for(int i=0;i<nStartPos.length;i++) Jh\KVmfXN
fileSplitterFetch.splitterStop(); &nmBsl3Q.
f-F=!^.
{lds?AuK
} 2w.FC
} #kW=|8X
//负责部分文件的抓取 WzzA:X
**FileSplitterFetch.java ew1L+
*/ ..`c# O&
package NetFox; 1ubu~6
hV7EjQp
,j%\3g`
import java.io.*; QEJu.o
import java.net.*; WESD^FK
bsQ'kBD
J||g(+H>
public class FileSplitterFetch extends Thread { HJl?@&l/
5sY$
|xB`cSu(
String sURL; //File URL S F)$b
long nStartPos; //File Snippet Start Position @8W@I|
long nEndPos; //File Snippet End Position ud/!@WG
int nThreadID; //Thread's ID v<1@"9EH
boolean bDownOver = false; //Downing is over 84(Jo_9
boolean bStop = false; //Stop identical .V;,6Vq
FileAccessI fileAccessI = null; //File Access interface !4p{b f
j e\!0{
d8wGXNd7B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8>C4w 5kF
{ H9T~7e+
this.sURL = sURL; v^&HZk=(
this.nStartPos = nStart; #ZZe*B!s_
this.nEndPos = nEnd; 'Dfs&sm
nThreadID = id; p\[!=ZXFr\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FF8jW1
} \m7\}Nbz0/
3/RwCtc
;#Po}8Y=
public void run() ?T/4 =
{ k4sV6f
while(nStartPos < nEndPos && !bStop) s\d3u`G
{ <f7 O3 >
.BPd06y
0ca0-vY
try{ mlByE,S2E
URL url = new URL(sURL); $oW=N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w[z=x
httpConnection.setRequestProperty("User-Agent","NetFox"); :%gc Sm
String sProperty = "bytes="+nStartPos+"-"; ':4ny]F
httpConnection.setRequestProperty("RANGE",sProperty); 4u5j 7`O
Utility.log(sProperty); (XOz_K6c%K
iF`_-t/k
v/ry" W
InputStream input = httpConnection.getInputStream(); ranem0KQ)]
//logResponseHead(httpConnection); phDIUhL$z
1sXCu|\q
RC7F/|w.z
byte[] b = new byte[1024]; Xq1#rK(
int nRead; %E%=Za
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .w4|$.H
{ z_'^=9m
nStartPos += fileAccessI.write(b,0,nRead); n~lB}
//if(nThreadID == 1) _h1bVd-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sj ovL@X
} @JSWqi>
0eO!,/
$PMr)U
Utility.log("Thread " + nThreadID + " is over!"); >9w^C1"
bDownOver = true; 0s`6d;
//nPos = fileAccessI.write (b,0,nRead); a@? $#>
} F.TIdkvp
catch(Exception e){e.printStackTrace ();} 8fQ~UcT$
} 2[Bbdg[O
} ,i*rHMe
`)O9 '568
N~|f^#L
//打印回应的头信息 @6ckB (
public void logResponseHead(HttpURLConnection con) )nHMXZ>Td
{ MQ =x:p{
for(int i=1;;i++) Z&^vEQ
{ \B')2phE
String header=con.getHeaderFieldKey(i); -, +o*BP
if(header!=null) Yh]a4l0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bAt!S
Utility.log(header+" : "+con.getHeaderField(header)); ta&z lZt
else iB0r+IbR
break; U,b80%k:
} vT5GUO{5
} b$2=w^*
_U}|Le@ e
5{-Hg[+9
public void splitterStop() M0m%S:2
{ A]"6/Lr9P
bStop = true; k8E2?kbF
} uhq6dhhR
9ZOQNN<ex
_ (b4|hJ'
} Wda?$3!^q
-AnJLFY
~%\vX
/* ;R >>,&g
**FileAccess.java tLJ 7tnB
*//文件访问(定位，写) ,JH*l:7
package NetFox; #NT~GhWFf
import java.io.*; LEKE+775
a3A-N] ;f
`LFT"qnp
public class FileAccessI implements Serializable{ a\-5tYo`u
PM*lnd#J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V,ZRX}O
RandomAccessFile oSavedFile; [GknE#p
long nPos; UHY)+6qt]
{(-TWh7V
*)r_Y|vg
public FileAccessI() throws IOException (q"S0{
{ x^3K=l;N
this("",0); }f> 81[^
} aQhT*OT{Q
rDaiAx&
b0f6?s
public FileAccessI(String sName,long nPos) throws IOException |{MFo)
{ O0^Y1l
oSavedFile = new RandomAccessFile(sName,"rw"); 5UL5C:3R9
this.nPos = nPos; `iuQ.I
oSavedFile.seek(nPos); 3 } $9./+
} M|{KQ3q:9
TbMlYf]It
@bkSA
public synchronized int write(byte[] b,int nStart,int nLen) k;umLyz
{ g3n>}\xG>
int n = -1; Uwiy@T Z
try{ I-s$U T[p
oSavedFile.write(b,nStart,nLen); e,vgD kI;
n = nLen; <O9WCl
} t2ui9:g4j
catch(IOException e) Pw|/PfG
{ #SLiv
e.printStackTrace (); `5t~ Vlp
} 99h#M3@!
/\jRr7 Cd
-?T|1FA,
return n; ^-#:T
} PClwGO8'&
f$nZogaQ
ku v<
} +DT tKj
.:['&; k
eF8um$t9
/* bB.nevb9p
**SiteInfoBean.java =Oh/4TbW[
*/ Y$q--JA
package NetFox; TAM`i3{D
r-BqIoVT
aj+I+r"~
public class SiteInfoBean { >48)@sS
&)Wm rF
\LS s@\$ g
private String sSiteURL; //Site's URL bir tA{q
private String sFilePath; //Saved File's Path )Z?\9'6e4
private String sFileName; //Saved File's Name Y%rC\Ij/i
private int nSplitter; //Count of Splited Downloading File =>C3IR/
[Az^i>iH
nRZ T~S4
public SiteInfoBean() b|Ed@C
{//nSplitter的缺省值为5 p t{/|P
//default value of nSplitter is 5 >>7m'-k%D
this("","","",5); j|% C?N
} D2Kh+~l
n@e|PWu
$/i;UUd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) doe u`
{ fl9J
sSiteURL= sURL; N'5!4JUI
sFilePath = sPath; M\9p-%"L
sFileName = sName; {u7_<G7
this.nSplitter = nSpiltter; [\i1I`7pE
Q5v_^O<!
bF3}L=z
} NE$=R"<Gv
7^8<[8
\h/aD1&g
public String getSSiteURL() l< |)LDq~
{ r+l3J>:K
return sSiteURL; !U+XIr
} {,m W7
l3/?,xn
9s6d+HhM
public void setSSiteURL(String value) c/}bx52>u
{ *}i.,4+y
sSiteURL = value; F_%&,"$
} Q,f5r%A.
*j= whdw%J
[[:wSAO>6'
public String getSFilePath() b_0Xi
{ I%G6V a@
return sFilePath; FZtIC77X5
} ;,]Wtmu)7
[^-DFq5@
t"'aQr
public void setSFilePath(String value) Y_&)>;
{ C}GOwvAL>
sFilePath = value; H]W59-{a
} kO\aNtK
O7RW*V:G@
{7X80KI
public String getSFileName() Vz&!N/0i
{ ygp NMq#?X
return sFileName; NvfQa6?;
} 0l ]K%5#
Y;XEC;PXD
:u53zX[v
public void setSFileName(String value) Q<pL5[00fD
{ F4Gv=q)Z
sFileName = value; '`Z5.<n7p
} [& &9F};
n P4DHb&5
dAcy;-[[P
public int getNSplitter() ',p`B-dw
{ `H6kC$^Ofx
return nSplitter; F&lvofy23
} RI_3X5.KQ
ebS>_jD
!N1DJd
public void setNSplitter(int nCount) p9)'nU'\t
{ +K%4jIm
nSplitter = nCount; e[7n`ka '
} Hh8)d/D
} ~O}LAzGb
v [ 4J0
@nS+!t{
/* + >oA@z
**Utility.java x-/`c
*/ ^J]~&.l
package NetFox; 1yN/+Rq
hIPU%
.5zqpm
public class Utility { Og`w~!\
bgjo_!J+Pp
/r Hd9^Y
public Utility() Hb;#aXHSd
{ F\Gi;6a
:)\<
$>;U^-#3
} PI#xRKt
qffXm`k
//线程睡眠 8I'c83w
public static void sleep(int nSecond) <OcD[5
{ jR#g>MDKB
try{ Q!:J.J
Thread.sleep(nSecond); iC`K$LY4W
} !e>EDYbY
catch(Exception e) N(W;(7
{ [s4lSGh
e.printStackTrace (); z5v)~+"1
} 7N/v
} Nj_h+=UE!
Z`23z(+
//日志 pN"d~Z8
public static void log(String sMsg) DUxj^,mf,
{ ]N^a/&}*
System.err.println(sMsg); G:QaWqUb
} @""aNKA^r>
2#:h.8
7W6tz\Y
public static void log(int sMsg) $4y;F]
{ brGUK PB
System.err.println(sMsg); ([='LyH];z
} jd|? aK;(
} 0S0 ?\r
2Ke?*
u|.L73<j%
/* wPYz&&W
**TestMethod.java t%wC~1
*/ wvum7K{tI
package NetFox; c@%:aiEl
X/fk&Cp
e`fN+
public class TestMethod { LoQm&3/
#N?EPV$
xZ}1dq8
public TestMethod() -aPvls
{ ///xx/weblogic60b2_win.exe `g&<7~\=A
try{ y_:i'Ri.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C#`VVtei
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lf|5miO
SiteFileFetch fileFetch = new SiteFileFetch(bean); F7wpGtt
fileFetch.start(); eDR4c%
} x8xSA*@k
catch(Exception e){e.printStackTrace ();} ML!Zm[I9
FV>LD% uu
)pV5l|`
} "If]qX(w
ixZ w;+h
Gk0f#;
public static void main(String[] args) #8G(r9
{ w:P$S
new TestMethod(); FWv-_
} )>$@cH
} <o8j+G)K#
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