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)); ct3i^,i
} c}qpmWF
for(int i=0;i<nEndPos.length-1;i++) ZDFq=)0C
{ Qi`3$<W>
nEndPos = nStartPos[i+1]; [Xu8~c X
} bzNnEH`^]
nEndPos[nEndPos.length-1] = nFileLength; ?`U_|Yo
} /fp8tL2Y
} 3E|||3rf
jDY B*Y^F
fAULuF
//启动子线程 -`k>(\Q<d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9BtGzI\
for(int i=0;i<nStartPos.length;i++) F5Xb_&
{ TI7$J#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )_jboaNzwI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _:m70%i
nStartPos,nEndPos,i); A{zqr^/h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N3L$"g5^
fileSplitterFetch.start(); NlEyT9
} ~{Iw[,MJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CXrOb+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c6xr[tc%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZTzec zXpQ
nEndPos = " + nFileLength); 9<_hb1'
// fileSplitterFetch[nPos.length-1].start(); +x 3x
gLv+L]BnhH
|KYl'"5\
//等待子线程结束 kzZgNv#G;
//int count = 0; :.+w'SEn4M
//是否结束while循环 {:gx*4}q8
boolean breakWhile = false; ..8t1+S6]
#AGO~#aK
tw$EwNI[
while(!bStop) J=3{<Xl
{ hH1Q:}a
write_nPos(); _s^tL2Pc
Utility.sleep(500); lKejWT`;
breakWhile = true; k={D!4kKz
b\}a
U7x
for(int i=0;i<nStartPos.length;i++) SiaNL:
{ .jQx2O
if(!fileSplitterFetch.bDownOver) 4@0aN6Os
{ #7O7O~
breakWhile = false; e`4mrBtz|
break; cn} CI
} |M7C=z='
} cj2Smgw&>
if(breakWhile) gtuSJ+up
break; n{4iW_/D
zq</(5H
#g6_)B=S
//count++; H2jypVs$2
//if(count>4) A5Jadz~
// siteStop(); Dr.eos4 ~
} yf:0u_&]
u<:uL
^s6~*n<fH
System.err.println("文件下载结束！"); eV?%3h.
} ompr})c
catch(Exception e){e.printStackTrace ();} 7I[[S!((s
} { }/
#-B<u-
:(~<BiqR(
//获得文件长度 nN{DO:_o
public long getFileSize() RkG?R3e
{ \;0pjxq=
int nFileLength = -1; F\JS?zt2
try{ `?$-T5Rr
URL url = new URL(siteInfoBean.getSSiteURL()); QgU]3`z"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W@AHE?s6g
httpConnection.setRequestProperty("User-Agent","NetFox"); rB+ (
Hj >fg2/
mHMsK}=~
int responseCode=httpConnection.getResponseCode(); .vKgiIC:
if(responseCode>=400) r!!uA1!7
{ k5\V:P=#
processErrorCode(responseCode); fh =R
return -2; //-2 represent access is error .$-;`&0cZ
} D/=05E%[81
k$%{w\?Jf
Gk5'|s
String sHeader; ]#M"|iTR
2*D2jw
F4\:9ws
for(int i=1;;i++) R WY>`.su
{ Bdh*[S\u@E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c_qox
//Utility.log(in.readLine()); )$^xbC#j`3
sHeader=httpConnection.getHeaderFieldKey(i); ia\Gmh
if(sHeader!=null) %t&Lq}e
{ h{mzYy}b
if(sHeader.equals("Content-Length")) PNAvT$0LaZ
{ rmw}Ui"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qOG@MR(5
break; ByjfPb#
} 15{^waR6
} 3|$?T|#B
else jW#dUKS(
break; i%133in
} Tr;.%/4Q
} "-S!^h/v
catch(IOException e){e.printStackTrace ();} M %zf?>])
catch(Exception e){e.printStackTrace ();} +iN!$zF5]
2+pw%#fe
)b nGZ8h99
Utility.log(nFileLength); lJAzG,f
;fqp!|J
LF.i0^#J
return nFileLength; 4mY^pQ1=L
} EO+Ix7w
TQeIAy
;VCV%=W<
//保存下载信息（文件指针位置） MMa`}wSs
private void write_nPos() gs1
{ |6-9vU!LK?
try{ 60~*$`
output = new DataOutputStream(new FileOutputStream(tmpFile)); /TbJCZ
output.writeInt(nStartPos.length); MDa[bQNM
for(int i=0;i<nStartPos.length;i++) ZOqA8#\
{ *><j(uz!
// output.writeLong(nPos); '*Y mYU
output.writeLong(fileSplitterFetch.nStartPos); |8}y?kAC
output.writeLong(fileSplitterFetch.nEndPos); BpA7 z/
} KD#zsL)3
output.close(); >;G_o="X
} L`M{bRl+1
catch(IOException e){e.printStackTrace ();} !(bYh`Uy
catch(Exception e){e.printStackTrace ();} W9gQho%9b
} ;Uch
C,;<SV2#
fPN/Mxu
//读取保存的下载信息（文件指针位置） 5Zc
private void read_nPos() 8Ie0L3d-
{ |qpm
try{ @I Y<i5(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Flpl,|n a
int nCount = input.readInt(); ST#)Fl
nStartPos = new long[nCount]; 1;./e&%%
nEndPos = new long[nCount]; b?=r%D->w
for(int i=0;i<nStartPos.length;i++) :fX61S6)
{ ce4rhtkV
nStartPos = input.readLong(); q@1A2L\Om
nEndPos = input.readLong(); bg3kGt0
} c5f57Z
input.close(); 49/2E@G4.
} aEQrBs
catch(IOException e){e.printStackTrace ();} dG3?(}p+
catch(Exception e){e.printStackTrace ();} w2 (}pz:
} unYPvrd
&VjPdu57
U#Kw+slM
private void processErrorCode(int nErrorCode) ,-d2wzhW
{ :;#^gvH
System.err.println("Error Code : " + nErrorCode); *>iJ=H
} M2:3k
l+(B~v
5FJ%"5n&
//停止文件下载 !pa7]cZ
public void siteStop() .}R'(gN\6
{ mFpj@=^_G
bStop = true; *s1o?'e
for(int i=0;i<nStartPos.length;i++) V'.gE6we
fileSplitterFetch.splitterStop(); %D7^.
BR6HD7G
|a1zJ_t4
} UT_t]m
} w0>5#jq#r
//负责部分文件的抓取 R$/q=*k
**FileSplitterFetch.java ;rh=63g
*/ H6#SP~V
package NetFox; kYS\TMt,C
R8% u9o
z1e+Ob&
import java.io.*; zS\m8[+]
import java.net.*; @$ )C pg
,;= S\
"g!/^A!!
public class FileSplitterFetch extends Thread { + L5
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0"@p|nAa
String sURL; //File URL Wu?[1L:x
long nStartPos; //File Snippet Start Position n 8|
long nEndPos; //File Snippet End Position xNVSWi,
int nThreadID; //Thread's ID j~ qm5}
boolean bDownOver = false; //Downing is over toox`|
boolean bStop = false; //Stop identical T6,6lll
FileAccessI fileAccessI = null; //File Access interface |R Qa.^.
:rmi8!o
p_sqw~)^%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BI6`@}%7>
{ 1UH_"Q03
this.sURL = sURL; R<>uCF0
this.nStartPos = nStart; YH[HJ#:7r
this.nEndPos = nEnd; wlX K2D
nThreadID = id; `\-mqe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 apm,$Vvjy
} 6;\Tps;A
hcD.-(-;)
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public void run() "8yDqm
{ k*T&>$k}^
while(nStartPos < nEndPos && !bStop) "CT`]:GGK
{ ^W,x
kh*td(pfP9
FwSV \N+#'
try{ QtqE&j
URL url = new URL(sURL); 2Y9@[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gG6BEsGa,
httpConnection.setRequestProperty("User-Agent","NetFox"); BG@[m
String sProperty = "bytes="+nStartPos+"-"; ]FO)U
httpConnection.setRequestProperty("RANGE",sProperty); xHwcP21
Utility.log(sProperty); A `=.F
{$-\)K
_k5-Wd5Ypw
InputStream input = httpConnection.getInputStream(); }D#[yE,=\
//logResponseHead(httpConnection); q}7(w$&
fL R.2vJ
ez*O'U
byte[] b = new byte[1024]; cU=/X{&Om
int nRead; (@u"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v%2Jm!i+
{ o7 X5{
nStartPos += fileAccessI.write(b,0,nRead); u!VY6y7p
//if(nThreadID == 1) ;hU~nj+{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZGWZ2>k
} Q-S5("
/T/7O
h|&qWv
Utility.log("Thread " + nThreadID + " is over!"); so\8.(7n
bDownOver = true; xHdv?69,
//nPos = fileAccessI.write (b,0,nRead); !p"Ijz5
} {nmBIk2v
catch(Exception e){e.printStackTrace ();} x\XOtjJr
} 0Z~G:$O/i
} y <21~g=
EY 9N{
,1-#Z"~c
//打印回应的头信息 SSI('6Z/
public void logResponseHead(HttpURLConnection con) #kDJ>r |&-
{ ~Aq$GH4
for(int i=1;;i++) %L;'C v
{ +LAjh)m
String header=con.getHeaderFieldKey(i); lilF _y
if(header!=null) XB-l[4?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _:,U$W
Utility.log(header+" : "+con.getHeaderField(header)); H;eOrX{GT
else f0lK,U@P
break; ns[Q %_
} W_N!f=HW
} 4wQ>HrS)(
Gj([S17\0:
CpF&Vy K
public void splitterStop() S~LTLv:>
{ o5eFLJ6
bStop = true; Nl`8Kcv
} E; Z1HF R
['n;e:*
$3MYr5
} r6eApKZ>f6
0?nm`9v6
0FD+iID
/* WKPuIE:
**FileAccess.java Fs EPM"&?h
*//文件访问(定位，写) A `n:q;my
package NetFox; {]\!vG6
import java.io.*; 14v,z;HXj
=:-x;
@z)_m!yV1
public class FileAccessI implements Serializable{ #/Qe7:l
%@Ty,d:;=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (Q09$
RandomAccessFile oSavedFile; FO5'<G-
long nPos; 55T c
c,I|O' &k
cU'^ Ja?%
public FileAccessI() throws IOException Lcyj,R
{ $VCWc#
this("",0); #e8NF,H5
} KzC`*U[
[8QE}TFic
7o]p0iLej
public FileAccessI(String sName,long nPos) throws IOException /P/S0
{ Ug^v ]B9
oSavedFile = new RandomAccessFile(sName,"rw"); "xV9$m>
this.nPos = nPos; &N!;d E
oSavedFile.seek(nPos); [!E8C9Q#!
} LMvsYc~]q
BK1Aq3*)
IuQY~!
public synchronized int write(byte[] b,int nStart,int nLen) SrVJ Q~:>
{ `<L6Q2Y>j
int n = -1; c|'hs
try{ }~RH!Q1
oSavedFile.write(b,nStart,nLen); ,4wZ/r> d
n = nLen; Dab1^H!KT
} W|FPj^*t
catch(IOException e) L@{5:#-
{ g2<xr;<t^
e.printStackTrace (); qeyBZ8BG
} HEjrat;5
Wh)QCp0|n
X>#!s Lt
return n; QxmVImn"
} y^oSVj
Y`u.P(7#
q)uq?sZe
} @"m? #
IYy2EK[s
AdtAc$@xK
/* &r;4$7
**SiteInfoBean.java Pxj?W'|
*/ N*Owfr1N
package NetFox; ;Vad| -
j/R
.TURS
public class SiteInfoBean { B%L0g.D"
*}\!&Zk"
;q&>cnLDR
private String sSiteURL; //Site's URL Iky'x[p,D
private String sFilePath; //Saved File's Path ,!f*OWnZ
private String sFileName; //Saved File's Name shlL(&Py
private int nSplitter; //Count of Splited Downloading File .jhuC#x{/
#GYCU!
r)dT,X[}F
public SiteInfoBean() wK[xLf
{//nSplitter的缺省值为5 [;D4,@A
//default value of nSplitter is 5 3H%oTgWk
this("","","",5); > @ulvHL
} P(W7,GD,k
/R< Q~G|\
ipEsR/O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *fq=["O
{ Nd&u*&S
sSiteURL= sURL; eD*"#O)W
sFilePath = sPath; ".qh]RVjV
sFileName = sName; :_tsS)Q2m
this.nSplitter = nSpiltter; %cD7}o:u
1x]U&{do
ti'a^(
} zb}:wUR
>sP-)ZeuU[
`n7z+
public String getSSiteURL() b0i]T?#
{ #{ M$%l>
return sSiteURL; d;ElqRC&
} H;<hmbN?d
h]<Ld9
;b$(T5
public void setSSiteURL(String value) v.+-)RLQg
{ 74%,v|
sSiteURL = value; aF$HF;-y
} 3_IuK6K2
}@V(y9K
Rtn.cSd
public String getSFilePath() /r|^Dc Nx
{ 6tM CpSJ
return sFilePath; zQ}:_
} im_W0tGvF
{vAq08
a Kb2:1EQ
public void setSFilePath(String value) A1p;Ye>o~
{ P}H7WH
sFilePath = value; S@zsPzw
} E'e#axF;
Hq^sU%
>U9*
public String getSFileName() jd=k[Yqr
{ @3{'!#/
return sFileName; \{n]&IjA
} i 4eb\j
1P4jdp=~
oa+Rr&t'
public void setSFileName(String value) 0?ZJJdI3
{ 7 #_{UJ%
sFileName = value; x9 <cT'
} KLs%{'[7:
?T70C9
}7vX4{Yn
public int getNSplitter() @q2Yka
{ :h N*
return nSplitter; &-9wUZ
} rZ1${/6
ow ~(k5k:
_ EHr?b2
public void setNSplitter(int nCount) Y,B0=}
{ ,'F;s:WM,
nSplitter = nCount; kVQKP U
} Jk|c!,!
} DVRE;+Jt
m"~$JA u
[z`U9J
/* N>7INK
**Utility.java yuk64o2QE
*/ a>Uk<#>2?a
package NetFox; 6.2_UN^<
d)(61
:Cw|BX@??U
public class Utility { S[{#AX=0
8MM#q+8
%K /=7
public Utility() mT>56\63
{ x9~d_>'A
7f'9Dm`
RT8xU;
} X&t)S?eCos
2Q)"~3
//线程睡眠 rFSLTbTf
public static void sleep(int nSecond) &2MW.,e7s
{ (J][(=s;a
try{ wnP#.[,V
Thread.sleep(nSecond); zhU)bb[A
} c{6!}0Q4
catch(Exception e) bJ]g2C7`36
{ +o!".Hp
e.printStackTrace (); )wo'i]#2:
} =g2;sM/
} uOEy}&fH
IBC P6[
//日志 NHUx-IqOX
public static void log(String sMsg) G{i}z^n
{ \q(RqD
System.err.println(sMsg); 'd^U!l
} M/ 0!B_(R
P8Fq %k
EMmNlj6
public static void log(int sMsg) y1(smZU
{ Gb<)U[Hfd
System.err.println(sMsg); 0Oc' .E9
} pcv(P
} x,STt{I=
ngcXS2S_
?3Se=7 k
/* SY["dcx+
**TestMethod.java .:*V CDOM
*/ nfq
package NetFox; g9H~\w
vdYd~>w
{%'(IJ|5z
public class TestMethod { ]YQlCx`
B8'" ^a^&-
i))S%!/r~
public TestMethod() cV_nYcLkz
{ ///xx/weblogic60b2_win.exe C#`eN{%.YT
try{ uR|Jn)/m(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y{B|*[xM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @O5-w
SiteFileFetch fileFetch = new SiteFileFetch(bean); `ux U H#
fileFetch.start(); D:U:( pg
} 4T`u?T]
catch(Exception e){e.printStackTrace ();} d Ayof=
3205gI,
K~5QL/=1
} p}hOkx4R\
3aQWzEnh
:t8(w>oW
public static void main(String[] args) =M>1;Qr<Z/
{ D%N^iJC,9
new TestMethod(); =2BGS\$#
} j~(rG^T
} I&U?8
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