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)); k<nZ+! M
} %8B}Cb&2c
for(int i=0;i<nEndPos.length-1;i++) ojm @t
{ CAig]=2'
nEndPos = nStartPos[i+1]; !7O+ogL
} d=$Mim
nEndPos[nEndPos.length-1] = nFileLength; j;+b0(53
} Fbr;{T .
} 6m/r+?'
1Z/(G1
}1L4"}L.
//启动子线程 4$HhP,gL=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Fj8z
for(int i=0;i<nStartPos.length;i++) n:I,PS0H<
{ htO+z7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,a{P4Bq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;>U2|>5V
nStartPos,nEndPos,i); :DK {Vg6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z}77Eh<
fileSplitterFetch.start(); q<x/Hat)
} #X+JHl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IEL%!RFG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j1Y~_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !,_u)4
nEndPos = " + nFileLength); +[6G5cH
// fileSplitterFetch[nPos.length-1].start(); H*?t^
ANAVn@ [
1sy[@Q2b
//等待子线程结束 r(>@qGN
//int count = 0; o)M}!MT
//是否结束while循环 >jDDQ@
boolean breakWhile = false; ozyX$tp
<`8n^m*
{ T/[cu<
while(!bStop) T= 80,
{ kUb>^- -K
write_nPos(); 3,_aAgeE
Utility.sleep(500); o"s)eh
breakWhile = true; W<h)HhyG
k&M;,e3v6
`z}?"BW|
for(int i=0;i<nStartPos.length;i++) yt+L0wzzB
{ (fH#I tf
if(!fileSplitterFetch.bDownOver) [~+wk9P
{ 2"v6 >b%
breakWhile = false; >>4qJ%bL
break; sU<Wnz\[
} }`@vF|2L
} h6Ub}(Ov
if(breakWhile) :^lI`9'*R
break; LRxZcxmy
MVpGWTH@F
~p6 V,Q
//count++; C$=%!wf
//if(count>4) B&M%I:i
// siteStop(); SBu"3ym
} 4!{KWL`A
Ot0ap$&
TIqtF&@o4
System.err.println("文件下载结束！"); /$Ir5=B
} I.(,hFx;
catch(Exception e){e.printStackTrace ();} {S]}.7`l9(
} olB.*#gA
o+iiSTJEe
.D"m@~j7
//获得文件长度 +yG~T
public long getFileSize() tn\yI!a
{ /obfw^
int nFileLength = -1; a@K%06A;'
try{ R`5.[?Dt
URL url = new URL(siteInfoBean.getSSiteURL()); 4d4ZT?V[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;J( 8 L
httpConnection.setRequestProperty("User-Agent","NetFox"); V;VHv=9`o
3Y4?CM&0v
94`7a<&ZNL
int responseCode=httpConnection.getResponseCode(); LtF,kAIt7v
if(responseCode>=400) #FLb*%Nr
{ @}u*|P*
processErrorCode(responseCode); h%na>G
return -2; //-2 represent access is error tPWLg),
} oN~&_*FE
T3.&R#1M8-
caR<Kb:;*
String sHeader; ,$L4dF3
IxN9&xa
='r!g
for(int i=1;;i++) *\a4wZ6<3
{ :wyno#8`-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4}baSV
//Utility.log(in.readLine()); |fJ};RLI"
sHeader=httpConnection.getHeaderFieldKey(i); Jl8H|<g~/
if(sHeader!=null) m,_Z6=I:
{ #4NaL
if(sHeader.equals("Content-Length")) S"QWB`W2
{ Pl06:g2I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); se2!N:|R!G
break; bjW]bRw
} pZ{+c
} |-67\p]
else <]t%8GB2V
break; QD&`^(X1p
} u(.e8~s8
} B2vh-%63
catch(IOException e){e.printStackTrace ();} `:fZ)$sY
catch(Exception e){e.printStackTrace ();} j?\Qh
vkV0On
a 7V-C
Utility.log(nFileLength); *!t/"b
CJx|?yK2
.k%72ez
return nFileLength; ,.8KN<A2]'
} vzAaxk%
epe)a
oUlY?x1
//保存下载信息（文件指针位置） @CL{D:d
private void write_nPos() Y;M|D'y+
{ SYJD?&C;
try{ ?pmHFlx
output = new DataOutputStream(new FileOutputStream(tmpFile)); VQt0 4?
output.writeInt(nStartPos.length); ^ig' bw+WS
for(int i=0;i<nStartPos.length;i++) h 0Q5-EA
{ 9d659iC
// output.writeLong(nPos); ^98~U\ar
output.writeLong(fileSplitterFetch.nStartPos); Tn e4
output.writeLong(fileSplitterFetch.nEndPos); wH&!W~M
} :6 R\OeH+
output.close(); `wEb<H
} >z>!Luw
catch(IOException e){e.printStackTrace ();} '3fu
catch(Exception e){e.printStackTrace ();} s?}e^/"v
} :J@gmY:C
+.[ <%
,/I.t DH
//读取保存的下载信息（文件指针位置） ]y'>=a|T
private void read_nPos() =z69e%.
{ `p-cSxR_
try{ %p=M;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G`61~F%
int nCount = input.readInt(); :Yh+>c}N
nStartPos = new long[nCount]; xGg )Y#
nEndPos = new long[nCount]; F^BS/Yag
for(int i=0;i<nStartPos.length;i++) Qbn"=n2
{ J/aC}}5D
nStartPos = input.readLong(); CYP q#rd
nEndPos = input.readLong(); .@U@xRu7|
} ^"2J]&x`G
input.close(); Om\vMd@!
} 5L%'@`mX
catch(IOException e){e.printStackTrace ();} LckK\`mh
catch(Exception e){e.printStackTrace ();} Hg izW
} zu{P#~21
,!y$qVg'\f
PiIpnoM
private void processErrorCode(int nErrorCode) 2r?G6D|
{ K7:)nv E
System.err.println("Error Code : " + nErrorCode); -;m0R
} )9`qG:b'
l<LI7Z]A
AJ`h9%B
//停止文件下载 BM .~ 5\
public void siteStop() JIOR4'9
{ $ @`V
bStop = true; .j0$J\:i
for(int i=0;i<nStartPos.length;i++) ChPmX+.i_
fileSplitterFetch.splitterStop(); vMH
:q%M_
#rfiD%c
} UECK:61Me
} f+,qNvBY/
//负责部分文件的抓取 [!#L6&:a8
**FileSplitterFetch.java K`zdc`/
*/ m@v\(rT.
package NetFox; K=h9Ce
h2]P]@nW;W
>W+%8e
import java.io.*; !ons]^km
import java.net.*; MaQqs=
9vc2VB$
}@q`%uzi
public class FileSplitterFetch extends Thread { 6}Ci>_i4#
37.S\gO]
H=vUYz
String sURL; //File URL `0gyr(fES
long nStartPos; //File Snippet Start Position nT$SfGFj8
long nEndPos; //File Snippet End Position WO>nIo5Y
int nThreadID; //Thread's ID D8?Vn"
boolean bDownOver = false; //Downing is over s$`0yGmQ
boolean bStop = false; //Stop identical CxW>~O:
FileAccessI fileAccessI = null; //File Access interface c]o'xd,T8\
{]@= ijjf
YZ8>OwQz2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0-Ku7<a
{ V5>B])yQ
this.sURL = sURL; >jLY"
this.nStartPos = nStart; L\"d
this.nEndPos = nEnd; |TH\`U
nThreadID = id; DA,?}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %pL''R9VF
} 0znR0%~
_8UU'1d
'S&zCTX7j
public void run() wE`]7mA
{ 16(QR-
while(nStartPos < nEndPos && !bStop) AH7}/Rc
{ wc4{)qDE
Fq<A
V&2l5v
try{ 2eY_%Y0
URL url = new URL(sURL); bwMm#f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qqY"*uJ'
httpConnection.setRequestProperty("User-Agent","NetFox"); ItrDJ'
String sProperty = "bytes="+nStartPos+"-"; nMUw_7Y6
httpConnection.setRequestProperty("RANGE",sProperty); Fk7')?
Utility.log(sProperty); Am|%lj+1z
aeM+ d`f
:tg)p+KB
InputStream input = httpConnection.getInputStream(); ?GR"FmB(
//logResponseHead(httpConnection); ZKTz ,
;h
;dgp+
byte[] b = new byte[1024]; 7[XRd9a5(
int nRead; +\ .Lp 5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >KhOz[Zg
{ :':s@gqr
nStartPos += fileAccessI.write(b,0,nRead); 9qzHS~l
//if(nThreadID == 1) 0 /U{p,r6`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kis"L(C
} yWo; a
BW*rIn<?G
~=l;=7 T
Utility.log("Thread " + nThreadID + " is over!"); 7;wd(8
bDownOver = true; `|&O*`
//nPos = fileAccessI.write (b,0,nRead); @lrztM
} -x`@6
catch(Exception e){e.printStackTrace ();} :*9Wh
} ;iL#7NG-R
} &d^m 1
K1yzD6[eW
SoSb+\*@h
//打印回应的头信息 M%P:n/j
public void logResponseHead(HttpURLConnection con) )1`0PJoHE
{ j'"J%e]
for(int i=1;;i++) JU&c.p /
{ <6 Uf.u`
String header=con.getHeaderFieldKey(i); i$6ypuc
if(header!=null) Pw"-S?`(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,R* ]>'
Utility.log(header+" : "+con.getHeaderField(header)); p6!x=cW
else hT+_(>hT
break; VTY 5]|;
} .Vvx,>>D
} S3Xl
'e'cb>GnA
4O!ikmY:t
public void splitterStop() G3AesTT|
{ e8?jmN`2
bStop = true; l}A93jSL
} M&9+6e'-F
60?%<oJ oH
T!)(Dv8@F
} {q^[a-h>
i2SR{e8:GF
H9Q&tl9
/* O5T{eBo\
**FileAccess.java p}U ~+:v
*//文件访问(定位，写) Yufc{M00
package NetFox; $suzW;{#
import java.io.*; -;WGS o
B>P{A7Q
}y gD3:vN7
public class FileAccessI implements Serializable{ vy:Z/1q
&E5g3lf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'c$+sp ?
RandomAccessFile oSavedFile; %YqEzlzF
long nPos; <bEbweQrgm
m GYoM
k!'a,R:
public FileAccessI() throws IOException ,/|T-Ka
{ m#\dSl}
this("",0); bq0zxg%
} UH"%N)[
Em~>9f ?Q(
}`m/bgtFX
public FileAccessI(String sName,long nPos) throws IOException Ao&"r[oJSv
{ YNsJZnGr8#
oSavedFile = new RandomAccessFile(sName,"rw"); j3E7zRm] \
this.nPos = nPos; LyFN.2qw
oSavedFile.seek(nPos); V1B5w_^>h'
} p9{mS7R9T
>(t6.=
89(Q1R ?:
public synchronized int write(byte[] b,int nStart,int nLen) &\*(Q*2N
{ d5:c^`
int n = -1; j*r{2f4Rt
try{ m^;f(IK5
oSavedFile.write(b,nStart,nLen); nUOz\y
n = nLen; xdkZdx>N
} J<jy2@"tXo
catch(IOException e) M[,@{u/
{ g{&ui.ml&
e.printStackTrace (); ^.QzQ1=D
} k~1?VQ+?M
#!+:!_45
3L}A3de'
return n; St*h>V6
} PB\x3pV!}
u.xnOcOH!
\(2sW^fY
} sD#.Oq4&]y
.U]-j\
49HZ2`Y
/* pIqeXY
**SiteInfoBean.java c'yxWZEv
*/ r3UUlR/Do
package NetFox; 86F1.ve
>tW#/\x{
sLxc(d'A
public class SiteInfoBean { ER.}CM6{[
k~nBiV
YT(AUS5n
private String sSiteURL; //Site's URL :eVq#3}
private String sFilePath; //Saved File's Path A6(/;+n
private String sFileName; //Saved File's Name ,Ko!$29[
private int nSplitter; //Count of Splited Downloading File H"WprHe
hkQ"OsU
$yNS pNmT0
public SiteInfoBean() tK\~A,=
{//nSplitter的缺省值为5 E hMNap}5"
//default value of nSplitter is 5 z-)O9PV
this("","","",5); Lw>N rY(Y
} BnasI;yWb
#S"nF@
*gWwALGo5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $-sHWYZ
{ @E|}Y
sSiteURL= sURL; oXF.1f/h
sFilePath = sPath; #QMz<P/Gl6
sFileName = sName; )\$|X}uny&
this.nSplitter = nSpiltter; s?nR4
-nV9:opD
{_v#~595
} *0=j?~&
W7nw6;7=
ZPYS$Ydy
public String getSSiteURL() tY4;F\e2|A
{ ~Z'?LV<t
return sSiteURL; fI|Nc
} d7bS wL
i=2N;sAl
R4:b{)=O
public void setSSiteURL(String value) f) L
{ >~0Z& d
sSiteURL = value; qUb&
} t"oeQ*d%
92oFlEJ
8KzkB;=n
public String getSFilePath() lrIe"H@
{ L.JT[zOfb
return sFilePath; j1T#yt J
} 1bwOmhkS
^^ixa1H<
CRy|kkT
public void setSFilePath(String value) $ $mV d+
{ QoT;WM Z
sFilePath = value; ;9QEK]@
} p9-K_dw3X@
AFwdJte9e
; BHtCuY
public String getSFileName() O0H.C0}
{ z+X}HL
return sFileName; b@hqz!)l`
} '!B&:X)
J5,9_uo]
7s^'d,P
public void setSFileName(String value) X 0+vXz{~g
{ {]4LULq
sFileName = value; sK?twg;D*|
} HJ.-Dg5U
KHvYUTY
5]:U9ts#
public int getNSplitter() j^RmrOg,
{ NC6&x=!3
return nSplitter; H3-hcx54T
} (KZ{^X?a
Tpa5N'O
@-`*m+$U6
public void setNSplitter(int nCount) 3F^Q51:t
{ SNk=b6`9
nSplitter = nCount; ysnx3(+|
} ('+d.F[109
} F#5~M<`.o
yyTnL 2Y9
/PXzwP_(A
/* G7/ +ogV
**Utility.java 1<aP92/N&
*/ `r 4fm`<
package NetFox; XC#oB~K'
W=+ Y|R!
b4Ekqas
public class Utility { 6[AL|d DK
[AJJSd/:
nQ3A~ ()
public Utility() :e+jU5;]3
{ <<O$ G7c
*wjrR1#81x
-M#Wt`6A
} k$:|-_(w
C\hM =%
//线程睡眠 i SQu#p@
public static void sleep(int nSecond) B&"Q\'c
{ -MBxl`JU
try{ _Y m2/3!
Thread.sleep(nSecond); XW92gI<O
} w5 Li&m
catch(Exception e) @_{=V0
{ ?:eV%`7
e.printStackTrace (); ;5( UzQU
} DzRFMYBR
} pT6$DB#
+Vdpy(
//日志 ,|/f`Pl
public static void log(String sMsg) cPQiUU~W@
{ YtLt*Ig%
System.err.println(sMsg); 86a\+Kz%%L
} W[r>.7>?h
E' uZA
*/S_Icf
public static void log(int sMsg) Ab;.5O$y
{ t sRdvFFq
System.err.println(sMsg); A^SgI-y|
} )D%~`,#pQ
} @IZnFHN
~pky@O#b
)fAUum
/* l9"s>PU
**TestMethod.java ql~J8G9
*/ %J-GKpo/S
package NetFox; >y+B
`\ol,B_l
i,VMd
public class TestMethod { O^rDHFj,
b|(:[nB
|JsZJ9W+J
public TestMethod() Y}KNKO;
{ ///xx/weblogic60b2_win.exe `kSZX:=};
try{ hXya*#n#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G^@5H/)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9W);rL|5
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7a}k
fileFetch.start(); + >!;i6|
} b\,+f n
catch(Exception e){e.printStackTrace ();} y8xE 6i
wb ;xRP"w
(**oRwr%
} ]eV8b*d6
K:WDl;8(d
-D:b*D
public static void main(String[] args) 1{.9uw"2S
{ X5w$4Kj&4l
new TestMethod(); q1ma%eiN
} PZzMHK?hP
} iU:cW=W|M\
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