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)); %w;1*~bH
} >?H_A
for(int i=0;i<nEndPos.length-1;i++) <6~/sa4GN
{ \UVT_=Y
nEndPos = nStartPos[i+1]; O%rS;o
} TiwHLb9
nEndPos[nEndPos.length-1] = nFileLength; 7N&3FER
} gEX:S(1QP
} !&W"f#_Z
r>n8`W
LA(f]Xmc
//启动子线程 F>hVrUD8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?)i6:76(
for(int i=0;i<nStartPos.length;i++) T1Ln)CS?9
{ Py(wT%w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pZNlcB[Qn-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Iwd"f
nStartPos,nEndPos,i); \J#I}-a&j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J~PTVR
fileSplitterFetch.start(); 4c493QOd
} 2b vYF;<r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -M(58/y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ePFC$kMn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !YuON6{)
nEndPos = " + nFileLength); Y D1g]p
// fileSplitterFetch[nPos.length-1].start(); ^+YGSg7
CVn;RF6
U/~Zk@3j
//等待子线程结束 Wl}G[>P
//int count = 0; dvH67 x
//是否结束while循环 -F~9f>
boolean breakWhile = false; 6Wcn(h8%*
9 ;! uV>-H
8DmX4*
while(!bStop) `\}zm~
{ l7FZ;%&
write_nPos(); ]MBJ"1F
Utility.sleep(500); X]f#w
breakWhile = true; rSzXa4m(
/-cX(z 7
pRaoR
for(int i=0;i<nStartPos.length;i++) wN%DM)*k
{ ;U5x'}%0]
if(!fileSplitterFetch.bDownOver) c"_H%x<[
{ ~vvQz"
breakWhile = false; cUX]tiC0
break; m/"=5*pA
} zke~!"iq
} 7xa@wa?!L
if(breakWhile) RI<Yg#
break; jTxChR
:7AauoI
fuwpp
//count++; 0V>N#P]
//if(count>4) XzTH,7[n
// siteStop(); [sh"?
} #h|,GvmF<b
q2"'W|I
8Nl|\3nl-
System.err.println("文件下载结束！"); a(QZZq};S
} F(kRAe;
catch(Exception e){e.printStackTrace ();} 6 GevO3
} %A Du[M.
fgz'C?
e"8m+]
//获得文件长度 %l$&_xV-
public long getFileSize() 1*Fvx-U'
{ r:\5/0(
int nFileLength = -1; ;ZW}47:BS6
try{ q@!H^hd}
URL url = new URL(siteInfoBean.getSSiteURL()); H<}Fk9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C%7,#}[U/
httpConnection.setRequestProperty("User-Agent","NetFox"); i)^ZH#Gp
WoT z'
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int responseCode=httpConnection.getResponseCode(); ;<ma K*f\S
if(responseCode>=400) XIW:Nk!S
{ OU964vv
processErrorCode(responseCode); sV4tu(~
return -2; //-2 represent access is error g|*eN{g]uE
} af5`ktx
/8-VC"
%'g-%2C?
String sHeader; 2*;Y%NcP[
GP kCgb(
.2-JV0
for(int i=1;;i++) ^+l\YB7pD
{ (6y3"cbe
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +W3>Yg%)X
//Utility.log(in.readLine()); hb\Y)HSp/
sHeader=httpConnection.getHeaderFieldKey(i); wuCtg=
if(sHeader!=null) uNGxz*e
{ tcdn"]#U
if(sHeader.equals("Content-Length")) j24
{ Rm1`D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >u[1v
break; ZUI\0qh+
} "jJ)hk5e
} 9@a;1Wr/f
else P+|8MT0
break; h*LL(ow5
} s7.*o@G
} MOeLphY
catch(IOException e){e.printStackTrace ();} hCoLj6Vx
catch(Exception e){e.printStackTrace ();} 1EPOYvf%U
/'_ RI
RL)3k8pk
Utility.log(nFileLength); ASU\O3%%
n^)9QQ
Z|GkM5QH:
return nFileLength; T1di$8
} 6(^9D_"@
>Ga1p'8FtU
F|K4zhK
//保存下载信息（文件指针位置） N9|.D.#MF
private void write_nPos() `5&V}"lB
{ pREYAZh
try{ Y-{BY5E.
output = new DataOutputStream(new FileOutputStream(tmpFile)); $NRb'
output.writeInt(nStartPos.length); .*7UT~o=CS
for(int i=0;i<nStartPos.length;i++) OkUpgXU
{ !QspmCo+
// output.writeLong(nPos); 5hK\YTU
output.writeLong(fileSplitterFetch.nStartPos); `R?W @,@'
output.writeLong(fileSplitterFetch.nEndPos); xJGeIh5
} )fL*Ws6
output.close(); `\0a5UFR
} * v]UgPk
catch(IOException e){e.printStackTrace ();} Y\|J1I,Z4
catch(Exception e){e.printStackTrace ();} "A+F&C>
} w8ld*z
-y.AJ~T
k4rBS
//读取保存的下载信息（文件指针位置） xB+H7Ya
private void read_nPos() iCKwd9?)
{ 1hS~!r'qqv
try{ =lD]sk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O3: dOL/C
int nCount = input.readInt(); <]^D({`
nStartPos = new long[nCount]; BAHx7x#(
nEndPos = new long[nCount]; S$WM&9U
for(int i=0;i<nStartPos.length;i++) .Y.# d7TA
{ nHrCSfK
nStartPos = input.readLong(); mh]$g<*m
nEndPos = input.readLong(); .x8$PXjPG
} [1GEe
input.close(); D:EF@il
} H\bIO!vb
catch(IOException e){e.printStackTrace ();} Q>ytO'v1
catch(Exception e){e.printStackTrace ();} TMsoQ82
} j@!}r|-T
-`EoTXT*U
)&Bv\Tfjt
private void processErrorCode(int nErrorCode) >cL2PN_y
{ c<e\JJY5?
System.err.println("Error Code : " + nErrorCode); w'XgW0j{
} i@L2W>{P
,ua1xsZl&
f tDV3If
//停止文件下载 V p{5Kxq
public void siteStop() ,[L$
{ q04Dj-2<
bStop = true; -+_&#twU
for(int i=0;i<nStartPos.length;i++) 3PffQ,c[~
fileSplitterFetch.splitterStop(); p\S3A(
)7J>:9h
nDy=ZsK
} 7!;/w;C
} -+|[0hpw
//负责部分文件的抓取 G- WJlu
**FileSplitterFetch.java 6QQ oHYtZ
*/ LP /4e`
package NetFox; GGtrH~zx
s#ZH.z@J
GYxI$y0:
import java.io.*; 'O9=*L)X
import java.net.*; f34&:xz2U
<Q)}
926oM77
public class FileSplitterFetch extends Thread { ,c l<74d
|"v{RC0
eCD,[At/
String sURL; //File URL IoOnS)
long nStartPos; //File Snippet Start Position rK|&u v*b
long nEndPos; //File Snippet End Position BxYA[#fd}
int nThreadID; //Thread's ID 3=7h+ZgB
boolean bDownOver = false; //Downing is over |>GIPfVT
boolean bStop = false; //Stop identical H%aLkV!J
FileAccessI fileAccessI = null; //File Access interface ;(6lN<iU
|3ETF|)?
$t'I*k^N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |Eu~=J7@
{ [zEP|
this.sURL = sURL; . *xq =
this.nStartPos = nStart; ped Yf{T
this.nEndPos = nEnd; "\?G
nThreadID = id; y:[]+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %Oqe7Cx>+
} k|'Mh0G0
caD;V(
va2A@U
public void run() P@`"MNS
{ f om"8iL1
while(nStartPos < nEndPos && !bStop) !5!$h`g
{ t'x:fO?cp
of
-$z"74
try{ 'PYqp&gJ
URL url = new URL(sURL); w8I&:"^7<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |9Ks13?Ck
httpConnection.setRequestProperty("User-Agent","NetFox"); dvF48,kr
String sProperty = "bytes="+nStartPos+"-"; n ]}2O4j
httpConnection.setRequestProperty("RANGE",sProperty); ?<^AXLiKV
Utility.log(sProperty); ?I#hrv@
WPKTX,k
@6'E8NFl
InputStream input = httpConnection.getInputStream(); #2ASzCe
//logResponseHead(httpConnection); '$-,;vnP0
pY#EXZ#
+Z2<spqG
byte[] b = new byte[1024]; KXCmCn
int nRead; Q9tE^d+%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qFbUM;
{ )0MshgM
nStartPos += fileAccessI.write(b,0,nRead); })vr*[
//if(nThreadID == 1) E?U]w0g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u(WQWsN
} Go7hDmu
5?0gC&WfN
aZGDtzNG5h
Utility.log("Thread " + nThreadID + " is over!"); ,GP4I3D
bDownOver = true; 1?#9Kj{ql
//nPos = fileAccessI.write (b,0,nRead); -8 =u{n
} q'@Ei4
catch(Exception e){e.printStackTrace ();} eE`1;13;
} $: m87cR~
} y$V)^-U>fw
/Py>HzRE:
m>dcb 6B+g
//打印回应的头信息 y]f^`2L!8>
public void logResponseHead(HttpURLConnection con) fYM6wYJ
{ (H%d]
for(int i=1;;i++) CVG>[~}(9'
{ EFt`<qwj
String header=con.getHeaderFieldKey(i); cGzYW~K
if(header!=null) nYt\e]3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T&"dBoUq>G
Utility.log(header+" : "+con.getHeaderField(header)); `G0rF\[
else @"Fp;Je\bN
break; w[oQ}5?9'
} ?iEXFYJG
} dN/ "1%9)
l~!fQ$~
C!k9JAa$Z
public void splitterStop() =C>`}%XT}
{ zQ %z"tQ
bStop = true; #Y>%Dr&
} O| 6\g>ew
05VOUa*pb
BI.k On=
} D6)Cjc>a
OK?3,<x
L[Yp\[#-q
/* {F+M&+``
**FileAccess.java 'BdmFKy1
*//文件访问(定位，写) X>Xp&o
package NetFox; w*xUuwi
import java.io.*; }-q`&1!t
I<(.i!-x
0Q- Mxcj
public class FileAccessI implements Serializable{ 26#Jhb E+
/.kna4k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QJIItx4hE
RandomAccessFile oSavedFile; y(3c{y@~X
long nPos; Sa?5iFg
syW9Hlm
DkF2R @
public FileAccessI() throws IOException oD#<?h)(
{ J6( RlHS;
this("",0); +>WC^s
} qz=#;&ZU
<r+!hJ[s'
,*nZf|
public FileAccessI(String sName,long nPos) throws IOException g y e(/N+I
{ i B!hEbz
oSavedFile = new RandomAccessFile(sName,"rw"); =Kt9,d08x
this.nPos = nPos; ]O7.ss/2
oSavedFile.seek(nPos); Ns!3- Y
} m,gy9$
$]H=
hLytKPgt
public synchronized int write(byte[] b,int nStart,int nLen) :ONuWNY N
{ lO2T/1iMTW
int n = -1; [71#@^ye
try{ 4%!{?[$
oSavedFile.write(b,nStart,nLen); Y!= k
n = nLen; 29iIG 'N
} gF,[u
catch(IOException e) !&a;P,_Fb
{ Z]aK'
e.printStackTrace (); aq0iNbv@
} s@ 20#D
G V:$;
EAD0<I<>
return n; u3*NO )O
} iIGI=EwZ
A`x -L
iJZ|[jEDV
} JIP+ !2
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<K,% y(]
/* P!FEh'.
**SiteInfoBean.java r0\cc6
*/ 1~}m.ER
package NetFox; xS6(K
1.# |QX
kOs(?=
public class SiteInfoBean { KX?o nsZ
}3v'Cp0L
EY+/.=$x
private String sSiteURL; //Site's URL `]*%:NZP@
private String sFilePath; //Saved File's Path TZ?Os4+
private String sFileName; //Saved File's Name W8w3~
private int nSplitter; //Count of Splited Downloading File C%giv9a
9$Ig~W)
iO!27y
public SiteInfoBean() LnP3z5d(
{//nSplitter的缺省值为5 ?h/xAl
//default value of nSplitter is 5 CzYGq
this("","","",5); <,\ `Psa)N
} `AWy!}8
v`y6y8:>
;W]D ~X&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <0CzB"Ap
{ _|N}4a
sSiteURL= sURL; {jvOHu
sFilePath = sPath; gfi AK%
sFileName = sName; 6SE6AL<b
this.nSplitter = nSpiltter; 94\t1fE
6yY.!HRkr
!RS9%ES_?
} dXmV@ Noo
~A6"sb=
?a S%
public String getSSiteURL() wMGk!N
{ CdY8#+"
return sSiteURL; rah,dVE]
} c! @F
>1A*MP4
dm6~
public void setSSiteURL(String value) F*M|<E=
{ S=' wJ@?;
sSiteURL = value; "< v\M85&
} oK2pM18
u_PuqRcs
`-_N@E1'>
public String getSFilePath() " Ya9~6
{ Ir5WN_EaS
return sFilePath; n"6;\
} {Hl[C]25X
LOr|k8tL%
(zG.aaz*C
public void setSFilePath(String value) nU(DYHc+l
{ V }>n
sFilePath = value; Zk&h:c
} w5*Z!
Jic}+X*0
{^5?)/<
public String getSFileName() NBjeHtT
{ @b2`R3}9R
return sFileName; c8{]]
} YD\]{,F|
pQMtj0(y
MxOD8TDF4
public void setSFileName(String value) Q6IQV0{p
{ ,LZX@'5
sFileName = value; ?7jg(`Yh
} o%[U
Q$ri=uB;+
>`'O7.R
public int getNSplitter() {fV}gR2
{ <*|?x86~
return nSplitter; #`;/KNp 9
} WZZ4]cC
k%P;w1
fQ 7vL~E
public void setNSplitter(int nCount) Q6 ?z_0
{ ar.AL'
nSplitter = nCount; |>2FRPK
} JN'cXZJPn
} G^wtE90
@ {#mpDX
cCY/gEv
/* "w_N'-}#
**Utility.java Sm-wH^~KA
*/ FJNF%a)x2I
package NetFox; ?":'O#E
>u0w.3r#
4v'A\~ZU
public class Utility { ^V3v{>D>
0)!Ll*L!p
&\C [@_
public Utility() 93O;+Z5J
{ zf[`~g
8FkFM^\1L
in-C/m#
} KCuGu}
B*1W`f
//线程睡眠 nkDy!"K
public static void sleep(int nSecond) |3hY6aty
{ gRJfX%*F
try{ X|DO~{-au
Thread.sleep(nSecond); {@Y
} O 5Nb
catch(Exception e) }(XdB:C8
{ LN2D
e.printStackTrace (); =~KsS}`1,
} |=a}iU8
} :_kAl? eJ
J;$N{"M
//日志 wsU V;S*X%
public static void log(String sMsg) _-~`03 `!
{ jZoNi
System.err.println(sMsg); }/P5>F<H[
} o4b~4h{%
EGq;7l6u&?
nqVZqX@oE
public static void log(int sMsg) ,Gk}"w
{ mTNVU@TY=
System.err.println(sMsg); `Y=WMNy
} *i{Y9f8
} 8qEK+yi,
Rli:x
A@*:<Hs%
/* efP&xk
**TestMethod.java '3IC*o"
*/ dq1:s1
package NetFox; #-% A[7Cdp
JPn$FQD
k>jbcSY(z<
public class TestMethod { _ee dBpV
7Q w|!
eM7Bc4V
public TestMethod() `#-P[q<v-
{ ///xx/weblogic60b2_win.exe YC_5YY(k
try{ !QI\Fz?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :!a2]-D}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '})0!g<Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3bZIYF2@
fileFetch.start(); ORXm&z)
} wa=uUM_4u^
catch(Exception e){e.printStackTrace ();} b1XRC`Gy
>gwz,{
5}$b0<em~
} &UCsBqIY
4MuO1W-
2QpHvsl_
public static void main(String[] args) E{^XlY
{ Rm1A>1a:
new TestMethod(); A\_|un%
} p[lNy{u~M
} $;M:TpX
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