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)); Q^xk]~G$(
} m G+=0Rn^
for(int i=0;i<nEndPos.length-1;i++) "kVzN22
{ ^/}&z
nEndPos = nStartPos[i+1]; *.T?#H
} u&o$2 '8
nEndPos[nEndPos.length-1] = nFileLength; {([`[7B>a<
} nuA 0%K
} F]0 qt$GO
eq<!
j0{Qy;wP )
//启动子线程 >V\^oh)t]t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hL}ZPHA
for(int i=0;i<nStartPos.length;i++) cT;Zz5
{ t4hc X[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &Du S*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ['K}p24,
nStartPos,nEndPos,i); N9rAosO*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bu08`P9
fileSplitterFetch.start(); 80o'=E}"
} VZ 7(6?W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5IF$M2j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Krl9O]H/[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H_aG\
nEndPos = " + nFileLength); .t&G^i'n
// fileSplitterFetch[nPos.length-1].start(); Zzb?Nbf
bUYjmb2g)
nC!L<OMr
//等待子线程结束 EP+LK?{%
//int count = 0; Z B!~@Vf
//是否结束while循环 U9 mK^
boolean breakWhile = false; sN#ju5
$>+g)
dI!/H&`B]
while(!bStop) 6mgLeeY
{ mGkQx -|
write_nPos(); (<e<Q~(
Utility.sleep(500); B`jq"[w]-
breakWhile = true; 1i)3!fH0:
=([4pG
_,d<9 Y)
for(int i=0;i<nStartPos.length;i++) &rl;+QS
{ roBb8M|q
if(!fileSplitterFetch.bDownOver) $3%+N|L
{ hMV>5Y[s
breakWhile = false; OkCAvRg
break; | :id/
} x]3[0K5;
} ]IzD`
if(breakWhile) K%Bz6 ~
break; V\l@_%D[(v
d9%P[(yM^
j9vK~_?;
//count++; [8 H:5Ho
//if(count>4) Q7tvpU
// siteStop(); 6GqC]rd*:
} /{W6]6^
tvq((2
#l7v|)9v
System.err.println("文件下载结束！"); B<a` o&?
} eg1F[~YL/
catch(Exception e){e.printStackTrace ();} ,(f W0d#
} Ed2A\S6tl
uv^x
HIC!:|
//获得文件长度 Htln <N
public long getFileSize() & Y2xO
{ Bvh{|tP4
int nFileLength = -1; 1i'y0]f
try{ nr,Z0
URL url = new URL(siteInfoBean.getSSiteURL()); PrA(==FX/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xkg
httpConnection.setRequestProperty("User-Agent","NetFox"); ["4Tn0g ;
!ab ef.%:
)}t't"
int responseCode=httpConnection.getResponseCode(); L' bY,D(J>
if(responseCode>=400) >mG64N
{ Zj1bG{G=i
processErrorCode(responseCode); 5Z6MQ`(k
return -2; //-2 represent access is error YhqMTOw
} TU*EtE'g/
bX`Gv+
&|db}\jT
String sHeader; KC9e{
?)(-_N&T
4"\cA:9a
for(int i=1;;i++) .aVtd [
{ 3dolrW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K>b4(^lf
//Utility.log(in.readLine()); U~;tk@
sHeader=httpConnection.getHeaderFieldKey(i); +lhCF*@*N
if(sHeader!=null) =;b3i1'U
{ qd#7A ksm
if(sHeader.equals("Content-Length")) >}W[>WReI
{ het<#3Bo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N-Z=p)]
break; _{gqi$Mi
} 2gMG7%d
} AQT_s9"0
else 4l68+
break; M}f(-,9
} cO5zg<wF
} +mzLOJed
catch(IOException e){e.printStackTrace ();} P".IW.^kk~
catch(Exception e){e.printStackTrace ();} `|nCnT'
Im@OAR4,R
tMp!MQ
Utility.log(nFileLength); {*[(j^OE
{ I\og
G -+!h4p
return nFileLength; slUi)@b
} 5gqs"trF
Y$]zba
/F(n%8)Yq
//保存下载信息（文件指针位置） K7K/P{@9[9
private void write_nPos() o[iN/
{ +}a(jO
try{ 6Io}3}3
output = new DataOutputStream(new FileOutputStream(tmpFile)); L/`1K_\l
output.writeInt(nStartPos.length); Y:t?W
for(int i=0;i<nStartPos.length;i++) WvSm!W
{ Lhe&
// output.writeLong(nPos); tp>YsQy]8
output.writeLong(fileSplitterFetch.nStartPos); 6$'*MpYF4
output.writeLong(fileSplitterFetch.nEndPos); 5)eM0,:
} El;"7Qn
output.close(); <r$h =hM
} g=Vu'p 3u
catch(IOException e){e.printStackTrace ();} ' BS.:^
catch(Exception e){e.printStackTrace ();} (;%T]?<9#
} @z{SDM
ZH9Fs'c=
J{Kw@_ypP
//读取保存的下载信息（文件指针位置） ZDgT"53
private void read_nPos() ^-[ I;P
{ =CZRX' +yN
try{ UU MB"3e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6[c|14l
int nCount = input.readInt(); !$oa6*<1
nStartPos = new long[nCount]; |D"L!+J-$
nEndPos = new long[nCount]; #?jsC)
for(int i=0;i<nStartPos.length;i++) Z?!AJY
{ tHZ"o!(S
nStartPos = input.readLong(); Zr2!}jD9a
nEndPos = input.readLong(); L\:m)g,F.
} Ez5t)l-
input.close(); Opcszq5n
} )`f-qTe
catch(IOException e){e.printStackTrace ();} ~ILv*v@m
catch(Exception e){e.printStackTrace ();} &{a!)I>
} 6AG]7d<
UGy3B)
to</
private void processErrorCode(int nErrorCode) ,.>9$(s
{ h%ys::\zF
System.err.println("Error Code : " + nErrorCode); WcNQF!f
} L'?aoRj
M-Efe_VRQc
L%is"NZh
//停止文件下载 Af]zv~uM
public void siteStop() #NYnZ^6e
{ dR1IndZl
bStop = true; *YvtT(Gt
for(int i=0;i<nStartPos.length;i++) ;'8P/a$
fileSplitterFetch.splitterStop(); d\]KG(T
%bN{FKNN
LkS tU)
} eTvjo(Lvx
} vu\W5M
//负责部分文件的抓取 'kt6%d2
**FileSplitterFetch.java Jcze.t
*/ M?"4{
package NetFox; f/UU{vX(
O0L]xr
Y$v#>w_M
import java.io.*; }_zN%Tf~
import java.net.*; i~]60M>
K}re{y
?j.a>{
public class FileSplitterFetch extends Thread { oOpEpQ}}q
K9%rr_ja!
GEc-<`-
String sURL; //File URL /g{*px|
long nStartPos; //File Snippet Start Position QjY}$
long nEndPos; //File Snippet End Position ;QXg*GNAv$
int nThreadID; //Thread's ID 81{8F
boolean bDownOver = false; //Downing is over FXJ0 G>F
boolean bStop = false; //Stop identical KqntOo} y)
FileAccessI fileAccessI = null; //File Access interface 6GunEYK!N8
KMIe%2:b5
g:Qq%'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $J4\jIipL
{ uK" T~
this.sURL = sURL; #ay/VlD@
this.nStartPos = nStart; p]RQ-0
this.nEndPos = nEnd; f)T\
nThreadID = id; :KO&j"[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Hvk~BP' m
} YXWDbr:JX
3(V0,L'1
Ct)58f2
public void run() t/Io.d
{ S2'ai
while(nStartPos < nEndPos && !bStop) n/1t UF
{ N E9,kWI
crb^TuN
u:pOP
try{ 0(-4"u>?
URL url = new URL(sURL); Li5&^RAo|J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &f.|MNz;
httpConnection.setRequestProperty("User-Agent","NetFox"); ~ q-Z-MA
String sProperty = "bytes="+nStartPos+"-"; uG7]s]Wdz;
httpConnection.setRequestProperty("RANGE",sProperty); {OPEW`F
Utility.log(sProperty); b VEJ
8S8qj"s
/lC# !$9vz
InputStream input = httpConnection.getInputStream(); doL-G?8B
//logResponseHead(httpConnection); ,K,st+s|
5m~9Vl-&
5]dlD #
byte[] b = new byte[1024]; EX_j|/&tZ
int nRead; ~NK $rHwi%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (o|bst][S
{ =8 @DYz'
nStartPos += fileAccessI.write(b,0,nRead); O`y3H lc
//if(nThreadID == 1) <CuUwv 'A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7/~=[#]*
} 0`S{>G
*MmH{!=
5oG~Fc
Utility.log("Thread " + nThreadID + " is over!"); Am*IC?@tq
bDownOver = true; B%\&Q@X
//nPos = fileAccessI.write (b,0,nRead); _\\Al v.
} ]\^O(BzB
catch(Exception e){e.printStackTrace ();} {BJ>x:2
} ir}z^+
} _ VuWo
0V3dc+t)O
%mmV#vwp
//打印回应的头信息 .hx(9
public void logResponseHead(HttpURLConnection con) e7GYz7
{ A*DN/lG
for(int i=1;;i++) ,]1f)>
{ 4ekwmw(ox
String header=con.getHeaderFieldKey(i); jr)M],
if(header!=null) ,1~zYL?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2|bt"y-5r
Utility.log(header+" : "+con.getHeaderField(header)); kfnh1|D=aY
else Qq:}Z7 H
break; Q$5t~*$`
} F62 uDyY
} RWR{jM]V
5?$MZaT
>gp53\
public void splitterStop() v)O0i2
{ 3/]1m9x
bStop = true; E$ \l57
} [Ep'm
]+Whv%M
@LOfqQ$FE
} /lECgu*#69
&fB=&jc*j
GPLop/6
/* K/*R}X
**FileAccess.java >niv>+!N
*//文件访问(定位，写) t>"`rcg
package NetFox; 8/>.g.]
import java.io.*; EY"of[p
zp8x/,gwF
fCUx93,>z
public class FileAccessI implements Serializable{ ZS+m}.,whQ
8i[TeW"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Kuh3.1#o
RandomAccessFile oSavedFile; H(;@7dh
long nPos; [z!m
r2#G|/=@
lUjZ=3"'
public FileAccessI() throws IOException _<f%== I'
{ /g>-s&w
this("",0); y%vAEQ2j=
} h.R46:
O W.CU=XU
w98M#GqV
public FileAccessI(String sName,long nPos) throws IOException GAY?F
{ 9BZ B1oX
oSavedFile = new RandomAccessFile(sName,"rw"); X[.%[G|oj}
this.nPos = nPos; Ydrh+
oSavedFile.seek(nPos); 2 %fcDEG/
} # l9VTzi
^^}htg
7NRa&W2
public synchronized int write(byte[] b,int nStart,int nLen) Zocuc"j
{ Kkq-x'gt^
int n = -1; Y$v d@Q
try{ XdA]);,
oSavedFile.write(b,nStart,nLen); ykbfK$jz
n = nLen; T&[6
} ~9o@1TO:v
catch(IOException e) `r1j>F7Xb
{ VB905%
e.printStackTrace (); F#|y,<}<
} ahgP"Qz
<k8WnA ~Fl
T+T)~!{%
return n; ~/A2:}Cp=
} NpGi3>5
8B-PsS|'
EE]xZz>o
} 1/mBp+D
>[wxZ5))
4J[zNB]
/* neu<zSS
**SiteInfoBean.java (L4llZ;q
*/ j)8$hK/e0.
package NetFox; ">=Ep+ix
ZFMO;'m&
mg:kVS
public class SiteInfoBean { QaLaw-lx
>x%HqP#_V
4r_*: $g
private String sSiteURL; //Site's URL !D1#3?L
private String sFilePath; //Saved File's Path ~6t<`&f
private String sFileName; //Saved File's Name 7l-MVn_8
private int nSplitter; //Count of Splited Downloading File =U~53Tg
hwUb(pZ
,k_ b-/
public SiteInfoBean() <=_!8A
{//nSplitter的缺省值为5 BYdGK@ouk
//default value of nSplitter is 5 8aHE=x/TL
this("","","",5); [L-wAk:Fb
} Kn$t_7AF^
4P?`<K'
f%n ;Z}=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .n_Z0&i/w
{ I-8I/RRkmP
sSiteURL= sURL; #*9 |\
sFilePath = sPath; 'wFhfZB1!B
sFileName = sName; ?4wl
this.nSplitter = nSpiltter; `0%;Gz%}
[bKc5qp
bHm/ZZx
} S=S/]]e
!W,LG$=/
jQ7;-9/~N
public String getSSiteURL() e~*tQ4
{ !/H `
return sSiteURL; =?4[:#Rh
} AW\uE[kg
2sgp$r
9Bpb?
public void setSSiteURL(String value) ?{ \7th37
{ #]^C(qmb:
sSiteURL = value; ~G8l1dD
} s+_8U}R
z|],s]F>G
-]}#Z:&
public String getSFilePath() lmUCrs37
{ 5`&@3 m9/
return sFilePath; 4`o0?_.'
} vq9O|E3
IDpLf*vSG
@g`|ob]9
public void setSFilePath(String value) )(.g~Q:
{ 8cvSA&l(D
sFilePath = value; 0iC5,
} 1,zc8>M
-#;ZZ\fdj
%L)QTv/
public String getSFileName() BE&8E\w
{ *1-0s*T
return sFileName; JgHYuLB
} dg*xo9Xi`
EJz!#f~
. WJ
public void setSFileName(String value) R$IsP,Uw
{ O5:U2o-
sFileName = value; SR.xI:}4
} G3!O@j!7w$
K5bR7f:
[giw(4m#y
public int getNSplitter() RWu< dY#ym
{ $L|+Z>x
return nSplitter; .L^j:2(L
} s!D?%
xh<{lZ)KJ
hxJKYU^%m
public void setNSplitter(int nCount) n]3'N58
{ Q$:,N=%
nSplitter = nCount; c*axw%Us
} h7.jWJTo
} u f<%!=e
m=COF$<
3qu?qD
/* 0S+$l
**Utility.java }9B},
*/ &\5bo=5V
package NetFox; |FaK=e
W:WRG8(F
3 %r*~#nz
public class Utility { 45Zh8k
o&k,aCQC
*yZta:(w-W
public Utility() >}0H5Q8@
{ 1PWi~1q{Q
3AP=
Yc)Dx3
} &{wRBl#
mo4F\$2N
//线程睡眠 Y>E` 7n
public static void sleep(int nSecond) zcOm"-E-
{ ^I6Vz?0Jl
try{ c9nv=?/}f
Thread.sleep(nSecond); )FA:wsy~E
} FW3E UC)P
catch(Exception e) m4~~q[t
{ R;U4a2~
e.printStackTrace (); 2Z"\%ZD
} F!?f|z,/
} N48X[Q*
ox.kL
//日志 MR@Qn[RdM
public static void log(String sMsg) 0[uOKFgE
{ G:|]w,^i
System.err.println(sMsg); 8WQc8
} pfl^GgP#
XfIsf9
#{k+^7aQ
public static void log(int sMsg) cj2^wmkB
{ o?= &kx
System.err.println(sMsg); >*^SQ{9
} Z;R/!Py.
} VggSDb
J5f}-W@
{SZv#MrK
/* vkYiO]y
**TestMethod.java siV]NI':|
*/ v$;URF%^
package NetFox; a7b1c!
U: <
J*%IvRg
public class TestMethod { |Zo36@s
&`]T#">
RA+M.
public TestMethod() M3d%$q)<rW
{ ///xx/weblogic60b2_win.exe x FvKjO)
try{ dgByl-8Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8{&.[SC7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %l%2 hvGZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?d3<GhzlR3
fileFetch.start(); w&hCtc
} [%Z{Mp'g
catch(Exception e){e.printStackTrace ();} @o<B>$tbu4
VGCd)&s
&[PA?#I`
} E3CwA8)k
;kG"m7-/
< jX5}@`z
public static void main(String[] args) *xx)j:Sc2
{ r0\C2g_X
new TestMethod(); MQ'=qR
} $.ctlWS8l{
} [ 'B u
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