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)); dhZZb
} CdDH1[J
for(int i=0;i<nEndPos.length-1;i++) ^eT@!N
{ o>0O@NE
nEndPos = nStartPos[i+1]; 1$);V,DK!
} T_uNF8Bh
nEndPos[nEndPos.length-1] = nFileLength; r|l53I5
} u/_Gq[Q,u
} 2dXU0095
`E{;85bDH
anK[P'Y
//启动子线程 (~=Qufy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C5>{Q:.`e'
for(int i=0;i<nStartPos.length;i++) XI]OA7Zis
{ Y_$^:LG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), = vY]G5y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &1*4%N@'
nStartPos,nEndPos,i); m &9)'o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \P*PjG?R
fileSplitterFetch.start(); P)Z/JHB
} )!N2'Ld
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }PtI0mZ1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iP2U]d~M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uy(vELB
nEndPos = " + nFileLength); 6lN?)<uQ
// fileSplitterFetch[nPos.length-1].start(); 8rGl&
{`+bW"9
A,3@j@bdy
//等待子线程结束 9@(O\xr
//int count = 0; 5tN%a>D%
//是否结束while循环 Bh\ [CY
boolean breakWhile = false; BXT80a\
n"XdHW0
]&&I|K_
while(!bStop) 8o!
{ (hpTJsZ
write_nPos(); :[A?A4l
Utility.sleep(500); |}M~kJ)
breakWhile = true; :5r:I[FFy
-;l`hRW
T^KCB\\<
for(int i=0;i<nStartPos.length;i++) 2.^7?ok
{ CbnR<W-j
if(!fileSplitterFetch.bDownOver) 5JQd)[Im
{ `K$:r4/[
breakWhile = false; bq c;.4$
break; /Lq;w'|I
} Sja"(sJ
} U,oD44
if(breakWhile) bk/.<Rt
break; +<'uw
NFdJb\
w;lx:j!Vp$
//count++; O4lxeiRgC
//if(count>4) {KW&wsI
// siteStop(); 6$W-?
} :`{9x%o;
B$K7L'e+-
nvU+XCx
System.err.println("文件下载结束！"); Ytl:YzXCi
} o@qN#Mg?>}
catch(Exception e){e.printStackTrace ();} F@>w&A~K
} N2[, aU
#gxRTx
1.hOE>A%
//获得文件长度 +9<,3IJe6
public long getFileSize() ,2=UuW"K
{ ,m #@%fa
int nFileLength = -1; ;s}-X_O<
try{ +W V@o'
URL url = new URL(siteInfoBean.getSSiteURL()); Iu=pk@*O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nG&w0de<>
httpConnection.setRequestProperty("User-Agent","NetFox"); T+&x{+gZ
h1Ke$#$6
I T*fjUY&
int responseCode=httpConnection.getResponseCode(); N&R '$w
if(responseCode>=400) , I[^3Fn
{ 27h/6i3
processErrorCode(responseCode); jK ?
return -2; //-2 represent access is error [+%p!T
} a(Gk~vD;"
wZ (uq?3S`
H;7O\
String sHeader; S+` !%hJ
K9x*Sep
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for(int i=1;;i++) y)N.LS
{ #Z2>TN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DI$mD{
//Utility.log(in.readLine()); [8V(N2
sHeader=httpConnection.getHeaderFieldKey(i); TE*>a5C|
if(sHeader!=null) #Pe\Z/
{ 9m<X-B&P
if(sHeader.equals("Content-Length")) B`RW-14g
{ t[H_6)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |Fh`.iT%c
break; (P]^8qc
} n:}MULy;
} [*mCa:^
else rsIt~w
break; "K4X:|Om"
} x|~D(zo
} 7|{%CckN
catch(IOException e){e.printStackTrace ();} ByB0>G''.
catch(Exception e){e.printStackTrace ();} mCEKEX
T }8r;<P6
p ] $
Utility.log(nFileLength); W#JVUGYD
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%8z+R m,Ot
return nFileLength; "6[Ax{cM
} KweHY,
OTy4"%
[nhLhl4S
//保存下载信息（文件指针位置） O*+w_fox
private void write_nPos() ?(`nBlWQ5
{ 5sffDEU]A
try{ kBDe*K.V
output = new DataOutputStream(new FileOutputStream(tmpFile)); Poylq]F
output.writeInt(nStartPos.length); D@YM}HXuj
for(int i=0;i<nStartPos.length;i++) o/i5e=9[y
{ 5 \.TZMB
// output.writeLong(nPos); N2S!.H!Wz
output.writeLong(fileSplitterFetch.nStartPos); $fU/9jTa
output.writeLong(fileSplitterFetch.nEndPos); a*$1la'Uf
} duiKFNYN
output.close(); 'nmYB:&!
} *}Ae9
catch(IOException e){e.printStackTrace ();} +Fy-~Mq
catch(Exception e){e.printStackTrace ();} ]i_):@
} <R]Wy}2-
$F /p8AraK
Z{R=h7P
//读取保存的下载信息（文件指针位置） Do{*cSd
private void read_nPos() tM?I()Y&P
{ FdK R{dX}
try{ wTJMq`sY_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |L~gNC
int nCount = input.readInt(); w~FO:/
nStartPos = new long[nCount]; 9N3oVHc?
nEndPos = new long[nCount]; .Q6{$Y%l
for(int i=0;i<nStartPos.length;i++) '!|E+P-
{ ht[TMdV
nStartPos = input.readLong(); ="[+6X
nEndPos = input.readLong(); YM,D`c[pX
} }O-%kl
input.close(); fxf GJNR
} 5G]#'tu
catch(IOException e){e.printStackTrace ();} {(zL"g46
catch(Exception e){e.printStackTrace ();} |SJ% _#=i
} 94>7-d
h.+,*9T\
e\bF_ N2VA
private void processErrorCode(int nErrorCode) })=c:h&
{ s-YV_
System.err.println("Error Code : " + nErrorCode); Lu$:,^ C
} {t IoC;Y
v:;C|uE|
9#=IrlV4
//停止文件下载 5x L,~"
public void siteStop() x:D<Mu#
{ `&&6-/
bStop = true; neMe<jr
for(int i=0;i<nStartPos.length;i++) .q& ]wu
fileSplitterFetch.splitterStop(); )F9%^a(
mrBhvp""
[4(A458H
} R/KWl^oNj
} I$P7%}
//负责部分文件的抓取 w]}cB+C+l#
**FileSplitterFetch.java JeSkNs|vB
*/ u[% J#S
package NetFox; ?[|4QzR
3By>t!~Q
"9Fv!*<-W
import java.io.*; 0z2R`=)
import java.net.*; E4fvYV_ra
vXWESy
,?skJ
public class FileSplitterFetch extends Thread { C&MqUj"]
+Y%I0.?&5
f>JzG,-
String sURL; //File URL 0i1?S6]d-
long nStartPos; //File Snippet Start Position XzRWY\x
long nEndPos; //File Snippet End Position sC*E;7gT,
int nThreadID; //Thread's ID [}g5Z=l
boolean bDownOver = false; //Downing is over &cv/q$W4
boolean bStop = false; //Stop identical N7|W.(
FileAccessI fileAccessI = null; //File Access interface "i5AAP?_]{
kO\&mL& qD
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'bqf?3W
{ ,Y/>*,J
this.sURL = sURL; c\?/^xr'!}
this.nStartPos = nStart; Mh@ylp+q
this.nEndPos = nEnd; U},W/g-
nThreadID = id; %li{VDb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K`mxb}
} !"qEB2r
}t{^*(
!7Q.w/|=
public void run() 9bYHb'70
{ Boz_*l|
while(nStartPos < nEndPos && !bStop) 6(;[ov1
{ p<.!::*%(
OaVL NA^{
\$++.%0
try{ _rWXcK3cjr
URL url = new URL(sURL); o0v m?CL#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _3?xIT
httpConnection.setRequestProperty("User-Agent","NetFox"); :zTj"P>"I
String sProperty = "bytes="+nStartPos+"-"; J'oz P^N
httpConnection.setRequestProperty("RANGE",sProperty); I,q~*d
Utility.log(sProperty); Gl\RAmdc
m*WEge*$t
p{_O*bo
InputStream input = httpConnection.getInputStream(); &5CeRx7%
//logResponseHead(httpConnection); 2Uw}'J_N
{ l~T~3/i
1JY90l$ME
byte[] b = new byte[1024]; t5[JN:an
int nRead; cF6@.)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (>% Vj
{ )FiU1E
nStartPos += fileAccessI.write(b,0,nRead); .Sth
//if(nThreadID == 1) rs KE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A^jm<~
} |[t=.dK%
0R{R=r]
Z\yLzy#8
Utility.log("Thread " + nThreadID + " is over!"); wH5O>4LO
bDownOver = true; _34YH5
//nPos = fileAccessI.write (b,0,nRead); #k]0[;1os
} ojI"<Q~g
catch(Exception e){e.printStackTrace ();} &~6O;}\
} cnO4NUDv
} HCZ%DBU96
iONql7S @
y3$\ m
//打印回应的头信息 ZI*A0_;L
public void logResponseHead(HttpURLConnection con) Z~:lfCK`
{ lP &%5y;
for(int i=1;;i++) Hw3ES
{ , 0ja_
String header=con.getHeaderFieldKey(i); ?~9X:~6\
if(header!=null) F>nrV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3m9E2R,
Utility.log(header+" : "+con.getHeaderField(header)); B}bNl 7 ~
else }Qu 7o
break; :Gk~FRA|
} |iThgq_\z
} f\_Q+!^
Xm+3`$<
` R-np_
public void splitterStop() Rla*hc~
{ `t"Kq+
bStop = true; &cejy>K
} ?n~j2-[<
6@361f[
u01^ABn
} jYx(
7q=xW6
|#,W3Ik(l
/* )W#g@V)>
**FileAccess.java 1e%Xyqb
*//文件访问(定位，写) Vi~+C@96
package NetFox; D*b|(Oi
import java.io.*; '\qr=0aW
UYLI>XSd
%-1-J<<J q
public class FileAccessI implements Serializable{ $VNn`0^gF
vCr$miZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /v<8x?=
RandomAccessFile oSavedFile; IKj1{nZvDc
long nPos; `2+52q<FO
l0o_C#"<S
k}7)pJNj
public FileAccessI() throws IOException Qc/J"<Lx
{ ?Cl"jcQ*
this("",0); &?pAt30K:
} z<XS"4l?W
At:C4>HE@
_JB3+0@
public FileAccessI(String sName,long nPos) throws IOException &WS%sE{p_
{ )8PL7P84
oSavedFile = new RandomAccessFile(sName,"rw"); A>S2BL#=
this.nPos = nPos; .w"O/6."
oSavedFile.seek(nPos); s_Gp +-
} .v!e=i}.
XS@6jbLE
jR:Fih-}
public synchronized int write(byte[] b,int nStart,int nLen) <Z_`^~!
{ CdjGYS
int n = -1; =@ RVLml
try{ Gd 9B
oSavedFile.write(b,nStart,nLen); F*u;'K
n = nLen; *O2j<3CHf
} p5ihuV,
catch(IOException e) 6=D;K.!
{ DO; 2)ZQ%
e.printStackTrace (); L x&ZWF$
} iddT.
-0Ek&"=Z^
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return n; ^~$ o-IX
} Qw+">
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f #14%?/
} J!>oC_0]8
fAi113q!
XhiC'.B_
/* kzT'
**SiteInfoBean.java *G4;
*/ 0v?,:]A0E
package NetFox; ,v+SD\7|
gf@Dy6<
!ywc).]e
public class SiteInfoBean { #SmWF|/
|SmN.*&(9
U;/ )V
private String sSiteURL; //Site's URL @AFLFX]
private String sFilePath; //Saved File's Path J^T66}r[f,
private String sFileName; //Saved File's Name FdD'Hp+
private int nSplitter; //Count of Splited Downloading File @2<J_Ja
"Y+`U
Yv)/DsSyL
public SiteInfoBean() Et(prmH
{//nSplitter的缺省值为5 P:+:Cm<
//default value of nSplitter is 5 Syb:i(Y
this("","","",5); jn'8F$GU
} z&8#1'
?.H*!u+9>
j(rFORT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 53c6dl
{ gQ[4{+DSf
sSiteURL= sURL; %WR
sFilePath = sPath; C/JFg-r
sFileName = sName; ]z,?{S
this.nSplitter = nSpiltter; ScD9Ct*):C
n9%rjS$
-Y6JU
} ME.LS2'n
jB;+tDC!Co
%AFy{l
public String getSSiteURL() R?(j#bk
{ GUxhCoxb
return sSiteURL; 6ZE]7~X
} TL5bX+
#{(rOb6H)
711z-
public void setSSiteURL(String value) Ni`qU(I'|
{ 1/ HofiIa
sSiteURL = value; Wd7*sa3T
} )-mB^7uXGv
8dv1#F|
1/ a,7Hl
public String getSFilePath() mEGMe@37
{ .*Z]0~ &|
return sFilePath; .IqS}Rh
} A6d+RAx
*\/UT
B?]^}r
public void setSFilePath(String value) `?)i/jko"
{ Y<B| e91C
sFilePath = value; ^l9S5 {
} <MYD`,$yu
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?^hC|IR$
public String getSFileName() ;tHF$1!J
{ tP\Utl-0
return sFileName; 5o,82Kti
} sG3%~
{MHr]A}X\
@M1U)JoQ
public void setSFileName(String value) f-Sb:O!V
{ 5b&'gd^d
sFileName = value; 30<^0J.1
} \Tc$P#
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g {00i
public int getNSplitter() ;y"DEFs,u
{ qU"+0t4
return nSplitter; *StJ5c_kg2
} M8h9i2
wDsEx!\#
fE(rDQI
public void setNSplitter(int nCount) 'b-}KDP
{ qZ4DO*%b3
nSplitter = nCount; )T^hyi$
} `8L7pbS%,Q
} O@l`D`
Z@1rs#
3+)i23[4=\
/* z=!xN5
**Utility.java >Zr`9$i
*/ ?g!)[p`v
package NetFox; q|S }5
=4?m>v,re
O:1YG$uKa
public class Utility { B"G;"X
k'm!|
HxkhlNB
public Utility() spJB6n(
{ #q%&,;4
c(o8uWn
oM< 9]jK}
} IkD\YPL;
.7oz
//线程睡眠 Mq$e5&/
public static void sleep(int nSecond) BsxQW`>^y
{ f;QWlh"9
try{ `S%pD.g,2
Thread.sleep(nSecond); f@Db._E
} 'E6)6N
catch(Exception e) myH#.$=A
{ Ra.<D.
e.printStackTrace (); v-OaH81&R
} cd\0
} ucyxvhH^-
_Nw-|N.
//日志 /KH3v!G0
public static void log(String sMsg) syMB~g
{ 8USF;k
System.err.println(sMsg); !}U&%2<69
} Fe8xOo6
3rs=EMz:w
>*EcX3
public static void log(int sMsg) -v`;^X
{ Bisht%]^
System.err.println(sMsg); k{uc%6s
} ^lf)9 `^U
} s2q#D.f
p5E|0p
+[:}<^p?cG
/* ZVViu4]?y
**TestMethod.java ^*RmT
*/ 7u0!Q\
package NetFox; evq*&.6\
j`(o\Fd )
Nn+leM
public class TestMethod { V*LpO8=
+tl&Jjdm
}]kzj0m
public TestMethod() {l![{
{ ///xx/weblogic60b2_win.exe H>k=V<
try{ !DXKn\aQf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jf@#&%AC9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UfXqcyY(
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5yuR[VU
fileFetch.start(); njX!Ez
} 6*Rz}RQ
catch(Exception e){e.printStackTrace ();} Jva&"}Cb
[Cvo^cC
hK3?m.>"g
} \ c9EE-
VQ2)qJ#l
QXniWJJ
public static void main(String[] args) c=h{^![$
{ [{L4~(uU8
new TestMethod(); !Hxx6/
} P'R!" #
} 7C F-?M!
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