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)); nM`)`!/
} -ZB"Yg$l
for(int i=0;i<nEndPos.length-1;i++) Exr7vL
{ 7E95"B&w
nEndPos = nStartPos[i+1]; R;o_*
} dc)Gk
nEndPos[nEndPos.length-1] = nFileLength; -eMRxa>
} qAS^5|(b[
} Nt8(
"x)DE,
[XXN0+ /
//启动子线程 W<Lrfo&=Y]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g$b*#
for(int i=0;i<nStartPos.length;i++) .IXwa,
{ pA'A<|)K0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?la_ +;m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), * 5n:+Tw(
nStartPos,nEndPos,i); J%)2,szn0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w%;'uN_
fileSplitterFetch.start(); 5[_8N{QC;
} o1Ln7r.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zTLn*?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sg-xm+iSDt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |BW,pT
nEndPos = " + nFileLength); S2)S/ nf
// fileSplitterFetch[nPos.length-1].start(); _LNPB$P
%j@FZ )a[
^&iV%vQ[
//等待子线程结束 u*{ _WL[(
//int count = 0; .a*$WGb
//是否结束while循环 1' m $_
boolean breakWhile = false; }Kt?0
%5%Wo(W'
8:xo ~Vc
while(!bStop) pC-OZ0
{ VaxO L61xE
write_nPos(); __j8jEV
Utility.sleep(500); nY)Pxahm7
breakWhile = true; w|C~{
aB^G
t5h_Q92N
for(int i=0;i<nStartPos.length;i++) Z<W6Avr
{ E6:p
if(!fileSplitterFetch.bDownOver) ^A`(
{ M;qL)vf
breakWhile = false; l #Q`f.
break; 7h1gU
} fh#_Mj+y
} sE6J:m(
if(breakWhile) \aIy68rH,
break; %%6('wi
Wg^cj:&`u
)/"7$2Aoy
//count++; &F_rg,q&_
//if(count>4) x[UO1% _o-
// siteStop(); u9w&q^0dqG
} Kdu\`c-lB
8F`
*K'ej4"u
System.err.println("文件下载结束！"); P*`xiTA
} Y)}%SP>,
catch(Exception e){e.printStackTrace ();} +o]BjgG
} Aw;vg/#~md
'V#ew\
N?0y<S ?!
//获得文件长度 C+XZDY(=Z
public long getFileSize() tr8Cx~<
{ +f!,K
int nFileLength = -1; F|TMpH/
try{ "R@N|Qx'
URL url = new URL(siteInfoBean.getSSiteURL()); u=o"^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @BUqQ9q:
httpConnection.setRequestProperty("User-Agent","NetFox"); AijTT%
$?AA"Nz
A(OfG&!
int responseCode=httpConnection.getResponseCode(); uz3pc;0LPY
if(responseCode>=400) xY2_*#{.
{ ROS"VV<
processErrorCode(responseCode); g ypq`F
return -2; //-2 represent access is error 7CM03R[P
} h6y4Ii
><Z3<7K9
{@__%=`CCS
String sHeader; J+jmSK%z
Cfo 8gX*
Lo5@zNt%W
for(int i=1;;i++) y[6&46r7D
{ jUvA<r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L~y tAZ,
//Utility.log(in.readLine()); 'h>5&=r
sHeader=httpConnection.getHeaderFieldKey(i); lc7a@qnw
if(sHeader!=null) M5WtGIV
{ /1~|jmi(
if(sHeader.equals("Content-Length")) 'QojSq
{ (0#F]""\e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5;8B!%b
break; \K~fRUo]=c
} ;c Co+(
} aroVyUs3j
else "%''k~UD4
break; &4&33D
} .#55u+d,
} 4z%#ZIy3
catch(IOException e){e.printStackTrace ();} |( 9#vt#
catch(Exception e){e.printStackTrace ();} )S};k=kG
jS3(>
F] ?@X
Utility.log(nFileLength); 4UD=Y?zK
kEhm'
ct4 [b|
return nFileLength; i4zV(
} Qy5Os?9"
D?yE$_3>c
<o!&Kk9
//保存下载信息（文件指针位置） _b_?9b-)D
private void write_nPos() ``|RO[+2
{ dMs||&|&
try{ {{*]bGko
output = new DataOutputStream(new FileOutputStream(tmpFile)); X";ZUp
output.writeInt(nStartPos.length); E<Dh_K
for(int i=0;i<nStartPos.length;i++) 6QLQ1k`
{ BCUt`;q ]B
// output.writeLong(nPos); BBR"HMa4
output.writeLong(fileSplitterFetch.nStartPos); &49$hF g6"
output.writeLong(fileSplitterFetch.nEndPos); Mp"'?zf
} ct}%Mdg
output.close(); qJ+52U|z
} W.`Xm(y
catch(IOException e){e.printStackTrace ();} Zfy~mv$
catch(Exception e){e.printStackTrace ();} -}X?2Q
} G/z\^Q
h!G^dW.
^@`e
//读取保存的下载信息（文件指针位置） .3&a{IxM]
private void read_nPos() -*%!q$:
{ /MqXwUbO
try{ z{pC7e5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A,-V$[;~D
int nCount = input.readInt(); ~z K@pFeH
nStartPos = new long[nCount]; m io1kDq<
nEndPos = new long[nCount]; =^Sw*[eiy
for(int i=0;i<nStartPos.length;i++) Bhu@2KdA
{ u-QO>3oY6
nStartPos = input.readLong(); 2zKo
nEndPos = input.readLong(); 1<a@p}
} y=9Dxst"V
input.close(); p2x1xv
} n{^<&GWox
catch(IOException e){e.printStackTrace ();} (7;J"2M
catch(Exception e){e.printStackTrace ();} q11QAx4p
} uKbHFF
b H"}w$!>r
j&dx[4|m:h
private void processErrorCode(int nErrorCode) vS$oT]-hKE
{ &{zwM |Q@?
System.err.println("Error Code : " + nErrorCode); &IRA=nJ
} ZUXse1,
s~LZOPN
*5y W
//停止文件下载 n{64g+
public void siteStop() V~T`&
{ '<%Nw-
bStop = true; @P_C%}(<
for(int i=0;i<nStartPos.length;i++) Any Zi'
fileSplitterFetch.splitterStop(); ]l=O%Ev
eu}Fd@GO
t=Z&eKDC
} T9z4W]T
} fW.GNX8
//负责部分文件的抓取 ,@Fgr(?'`>
**FileSplitterFetch.java p@/(.uE
*/ M|UxE/
package NetFox; YX ;n6~y
j|[(*i%7|
HDF"]l;
import java.io.*; 3}B5hht"D
import java.net.*; ADYx.8M|9i
8cK\myn.
/M^V2=
public class FileSplitterFetch extends Thread { 'Aj(i/CM
s(AJkO'`
|66m` <
String sURL; //File URL fJLf7+q
long nStartPos; //File Snippet Start Position #\pP2
long nEndPos; //File Snippet End Position b JfD\
int nThreadID; //Thread's ID # 0GGc.
boolean bDownOver = false; //Downing is over <i}q=%W!1
boolean bStop = false; //Stop identical (PS$e~Hs
FileAccessI fileAccessI = null; //File Access interface vpm ]9>1[
*o02!EYge
ORowx,(hX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vWU%ST
{ Opv1B2
this.sURL = sURL; +_qh)HX
this.nStartPos = nStart; ytjK++(T5
this.nEndPos = nEnd; H\^VqNK"
nThreadID = id; k> b&xM!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rIeM+h7Wn
} :E>&s9Yj?
rH9uGm-*
h?0F-6z
public void run() g1ZV&X=2
{ Abj97S
while(nStartPos < nEndPos && !bStop) XzT78
{ b fp,zs
\ Y*h
},DyU
try{ bh6d./
URL url = new URL(sURL); >0PUWr$8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f.||PH
httpConnection.setRequestProperty("User-Agent","NetFox"); LthGZ|>
String sProperty = "bytes="+nStartPos+"-"; Dd| "iA
httpConnection.setRequestProperty("RANGE",sProperty); +0]'| tF>
Utility.log(sProperty); nQ5N=l
7p)N_cJD
aZ`<PdA
InputStream input = httpConnection.getInputStream(); 9nn>O?
//logResponseHead(httpConnection); bvl~[p$W3
$^}[g9]1
ispkj'
byte[] b = new byte[1024]; PzjaCp'
int nRead; q@w{c=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1g1?zk8zO
{ 4P|$LkI
nStartPos += fileAccessI.write(b,0,nRead); G%a] j
//if(nThreadID == 1) XVw-G }5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pd d|n2q
} 1Gsw-a;a
}6).|^]\'
np\st7&f6
Utility.log("Thread " + nThreadID + " is over!"); "YJ[$TG
bDownOver = true; nO~b=qO
//nPos = fileAccessI.write (b,0,nRead); dM Y 0K
} %c]nWR+/
catch(Exception e){e.printStackTrace ();} ;a|`s
} re;Lg C
} 9#uIC7M
vYDSu.C@a
&vCeLh:s
//打印回应的头信息 eUt=n)*`
public void logResponseHead(HttpURLConnection con) );nz4/V
{ kI%peb?
for(int i=1;;i++) aD2*.ln><
{ C\ vC?(n
String header=con.getHeaderFieldKey(i); t9.,/o,
if(header!=null) j'+ELKQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A t{U~^
Utility.log(header+" : "+con.getHeaderField(header)); :q^R `8;(t
else ;{k=C2
break; BRb\V42i;
} 20aZI2sk`
} ;)?( 2 wP
AH^e]<2-
dIk'pA^d
public void splitterStop() B/mYoK
{ /|GT\X4o
bStop = true; KbAR_T1n
} MM#i t=u
mzGjRl=O
1?(cmXj
} *(G&B\
ahA{B1M)n
-0$:|p?@^
/* 'w(y J
**FileAccess.java ;K_}A4K
*//文件访问(定位，写) JWWYVl VC
package NetFox; \PbvN\L
import java.io.*; 3?2<WEYr
?q_^Rj$
}X]\VSF{
public class FileAccessI implements Serializable{ Kq&qE>Ju
Pt)S;6j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~wOTjz
RandomAccessFile oSavedFile; ["a"x>X&
long nPos; (ss3A9tG
:\b|dvI<
6PU/{c
public FileAccessI() throws IOException D+sQPymI
{ Lz@$3(2
this("",0); :&qhJtGo
} o'Wz*oY))\
5;mRGY
KY$k`f6?P
public FileAccessI(String sName,long nPos) throws IOException '.(~
{ H<`\bej,
oSavedFile = new RandomAccessFile(sName,"rw"); &vkjmiAS
this.nPos = nPos; CvK3H\.&;k
oSavedFile.seek(nPos); qbiK^gR
} X4wH/q^
(WRMaI72(
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public synchronized int write(byte[] b,int nStart,int nLen) fN)x#?
{ o@W_ai_
int n = -1; mu[Op*)
try{ SO;N~D1Z6
oSavedFile.write(b,nStart,nLen); 2no$+4+z
n = nLen; o5swH6Y.)J
} 7?J3ci\
catch(IOException e) byGn,m
{ qsI^oBD"
e.printStackTrace (); QXVC\@
} nBz`q+V
+j{Y,t{4
eY,O@'"8`
return n; |0sPka/u16
} #G#g|x*V
f+x;:
l%~lz[
} @g-G =Ba
yK1ie
,%[4j9#!_
/* "R[l ZJ@
**SiteInfoBean.java pu9^e4B9
*/ 7Xg?U'X
package NetFox; WC*=rWRxF
rrqQCn9
gEwd &J
public class SiteInfoBean { *geN[[
>&U@f
ST Z]8cw
private String sSiteURL; //Site's URL m#e*c[*G
private String sFilePath; //Saved File's Path V`#.7uUP
private String sFileName; //Saved File's Name C\}/"
private int nSplitter; //Count of Splited Downloading File lpgd#vr
y('k`>C
RWKH%C[Yd
public SiteInfoBean() eC! #CK
{//nSplitter的缺省值为5 -*B`]
//default value of nSplitter is 5 ?9mkRd}c
this("","","",5); (R*j|HAw`X
} ''H"^oS
n~.*1. P
6N~q`;p0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AjkW0FB:1
{ 65TfFcQ<S
sSiteURL= sURL; &GhPvrxI?
sFilePath = sPath; CnISe^h
sFileName = sName; uw AwWgl
this.nSplitter = nSpiltter; G[,Q95`w?<
X~oK[Nf'9
ik.A1j9oN
} vLT0ETHg6
mr:CuqJ
y_p.Gzy(^}
public String getSSiteURL() IiJZ5'{
{ #Sh <Ih
return sSiteURL; zMi; A6
} o}$1Ay*q`
"=1;0uy]
;*2>ES
public void setSSiteURL(String value) S( ^.?z
{ x,n,Qlb
sSiteURL = value; ~P.I<
} IkPN?N
k*mt4~KLT8
7zemr>sIh
public String getSFilePath() K`g7$r)U[
{ 3g~'5Ao
return sFilePath; _S}A=hK'
} V~@^`Gd
,%9df+5k
uXjP`/R|
public void setSFilePath(String value) em{(4!W>
{ P{Lf5V9# <
sFilePath = value; 2c5-)Dt)T
} &;&ho+qD
n>>Qn&ym
k,yZ[n|`
public String getSFileName() 5=|hC3h
{ j|4C\~i
return sFileName; E>|: D
} Dd/wUP
r SkUSe6
p5r]J+1
public void setSFileName(String value) 06q(aI^Ch@
{ -G7TEq)
sFileName = value; 2-N 'ya
} 4JGtI*%5lq
/U&Opo {aO
9h4({EE2t
public int getNSplitter() aJ") <_+
{ ~*A8+@\R
return nSplitter; 4)|8Eu[p7
} phnV7D(E
VHJM*&5
-h|B1*mt
public void setNSplitter(int nCount) !8NC# s
{ G 0%6ch^%
nSplitter = nCount; %w7u]-tR
} C?Bl{4-P}*
} #|&Sc_#4)
1i[FY?6`dh
nw>8GivO
/* 9RN-suE[
**Utility.java T&4qw(\G
*/ Ez|oN,
package NetFox; FKNMtp[`
(8.Z..PH
.qMOGbd?
public class Utility { 3b'QLfU&#
gL_Y,A~Q{
Bp8'pj;~
public Utility() F *FwRj
{ 3RLFp\i"s
Lzu.)C@Amx
ho##Z*O
} = C4
EkgE_8
//线程睡眠 &e6CJ
public static void sleep(int nSecond) &wD;SMr<
{ 35E_W>n
try{ :8CvRO*<
Thread.sleep(nSecond); 1$M@]7e+!+
} wr[,
catch(Exception e) At7>V-f}
{ &l3iV88
e.printStackTrace (); Oo"^%F~%
} Ag{iq(X
} d&ex5CU5
J5^'HU3
//日志 &boOtl^
public static void log(String sMsg) Zt.'K(]2h
{ Y. ,Kl~
System.err.println(sMsg); Jn{OWw2
} .C8PitS
f7m%|v!
B!vmQR*1
public static void log(int sMsg) IiY/(N+J
{ dZi"$ g
System.err.println(sMsg); 0TQ$C-%
} (h>-&.`&
} cSXwYZDx?
q Y#n'&
?>I;34tL(
/* I'V4D[H5
**TestMethod.java 0NS<?p~_S
*/ /YZr~|65
package NetFox; xuqv6b.
a)wJT`xu
,%uo6%
public class TestMethod { eeyHy"@
1oc3$A
|&RU/a
public TestMethod() N<~t3/Nm
{ ///xx/weblogic60b2_win.exe Ney/[3 A
try{ 8C*c{(4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3AU;>D^5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8_{X1bj
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z'"tB/=W
fileFetch.start(); ILGMMA_2
} a(l29>
catch(Exception e){e.printStackTrace ();} _d5QbTe
"wNJ
9I}-[|`u
} ,6-:VIHQ
Wk)OkIFR
\O2Rhz
public static void main(String[] args) 3B84^>U<
{ x[a<mk
new TestMethod(); vN`klDJgW[
} ibj87K
} vX/T3WV
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