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)); &S"ojbb
} EK6fd#J?1
for(int i=0;i<nEndPos.length-1;i++) :}Tw+S5
{ d= -/'_'
nEndPos = nStartPos[i+1]; $6XCHVx
} N3Jfp3_b@
nEndPos[nEndPos.length-1] = nFileLength; d M&BnI
} '<C I^5^
} |NcfR"[c
nsJN)Pt
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//启动子线程 yjbqby7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4S]`S\w
for(int i=0;i<nStartPos.length;i++) {{?[b^
{ @,63%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b1}P3W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <|s9@;(I
nStartPos,nEndPos,i); nKJJ7 RL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uYPdmrPB?l
fileSplitterFetch.start(); 8h#/b1\
} n(gw%w+\7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j6~#_t[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O0{M3-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $:%?-xy(
nEndPos = " + nFileLength); T/"6iv\1
// fileSplitterFetch[nPos.length-1].start(); XTHy CK
3JiDi X"|
Cr,UP8MO
//等待子线程结束 )hHkaI>eYv
//int count = 0; (N U*PQY6
//是否结束while循环 F(8>"(C
boolean breakWhile = false; dE+xU(\,w
qF{u+Ms
8}0W_CU,
while(!bStop) l("Dw8H
{ )j40hrR
write_nPos(); 7mSVL\\^
Utility.sleep(500); Elt=/,v`!
breakWhile = true; N4%q-fi
~h] <E
RpE69:~PV
for(int i=0;i<nStartPos.length;i++) dFF[2
{ Nkt(1?:-'
if(!fileSplitterFetch.bDownOver) &Z_W*D
{ W^W^5-'"D,
breakWhile = false; +'H_sMmi{
break; qJj;3{X2
} [e )j,Q1
} 1.0S>+^JE
if(breakWhile) Z,Z34:-
break; )z9)oM\
j5ZeYcQ-
Vc3tKuMsiX
//count++; kL,{H~iq;
//if(count>4) c,1Yxg]|
// siteStop(); ?Ovl(4VG
} ]k%Yz@*S
'w`:p{E
(z0S5#g ,x
System.err.println("文件下载结束！"); o[Yxh%T
} nJ#uz:(w,
catch(Exception e){e.printStackTrace ();} ~jb6
} s% "MaDz
/a%5!)NE%
K+D`U6&
//获得文件长度 #N%xr'H
public long getFileSize() u{'bd;.7
{ 5tg
int nFileLength = -1; +Eh1>m
try{ 4!<8Dd
URL url = new URL(siteInfoBean.getSSiteURL()); "z\T$/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5B!l6ST
httpConnection.setRequestProperty("User-Agent","NetFox"); BF2,E<^A
jRS0(8
/i$ mIj`
int responseCode=httpConnection.getResponseCode(); ^0R.U+?+
if(responseCode>=400) <8[BB7
{ BhkJ>4#
processErrorCode(responseCode); lvIKL!;H
return -2; //-2 represent access is error TdI5{?sW
} D*Y4B?,
(b Q1,y
^ad p<?q4
String sHeader; g]R }w@nJ
-$L53i&R
<k'=_mC_
for(int i=1;;i++) +qe!KPk2
{ ow*) 1eo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ci>+Zi6
//Utility.log(in.readLine()); eOjoxnD-$
sHeader=httpConnection.getHeaderFieldKey(i); R:98'`X=
if(sHeader!=null) D[m;rcl
{ U7.3`qd"
if(sHeader.equals("Content-Length")) ~]DGf(
{ Qj?+R F6(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [y|"iSD
break; {%xwoMVc+
} _e$15qW+
} a|`Pg1j#
else KFdTw{GlJ7
break; :3$WY<
} [!4p5;
} z%;b-PpS
catch(IOException e){e.printStackTrace ();} bE.,)GY
catch(Exception e){e.printStackTrace ();} NyI0[]z
'<~l%q
j^T.7Zv
Utility.log(nFileLength); m UpLD+-j
@ 9D, f
kt.z,<w5O
return nFileLength; +~\1Zgw
} |ul25/B B
5BCXI8Ox9x
fn )m$\2
//保存下载信息（文件指针位置） *SQ hXTn
private void write_nPos() ~h6aw
{ kDS
try{ >S3iP?V7
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9S@PY_ms
output.writeInt(nStartPos.length); 6Yebc_, R
for(int i=0;i<nStartPos.length;i++) +M!f}=H
{ pi:%Bd&F
// output.writeLong(nPos); r k;k:<c
output.writeLong(fileSplitterFetch.nStartPos); ^AK<]r<?L?
output.writeLong(fileSplitterFetch.nEndPos); WY#A9i5Ge
} XeDiiI
output.close(); `;4P?!WG
} Ro$'|}(+A
catch(IOException e){e.printStackTrace ();} K O"U5v
catch(Exception e){e.printStackTrace ();} =4uL1[0'
} Mib(J+Il
%mPIr4$Pg
e5_a.c
//读取保存的下载信息（文件指针位置） U7O~ch[,
private void read_nPos() ?9nuL}m!a
{ $5ZBNGr
try{ {^2``NYM_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eWSA
int nCount = input.readInt(); PXG)?`^NX
nStartPos = new long[nCount]; `q7O\
nEndPos = new long[nCount]; bB@1tp0+
for(int i=0;i<nStartPos.length;i++) 6lOT5C eJ"
{ `P<}MeJ\l
nStartPos = input.readLong(); !`L%wS
nEndPos = input.readLong(); 0Lmq?D
} 9F)+p7VJq
input.close(); n#XiCo_\
} "hi?/B#d
catch(IOException e){e.printStackTrace ();} g-"@%ps
catch(Exception e){e.printStackTrace ();} x zu)``?
} 4Tgy2[D?q
2{Nv&ZX?
%1ZJi}~
private void processErrorCode(int nErrorCode) yEyx.Mh.Af
{ dO}6zQ\
System.err.println("Error Code : " + nErrorCode); a]-F,MJ
} Y3+DTR0|'
iTF`sjL
&2[OH}4
//停止文件下载 8R"c}87
public void siteStop() hdt;_qa
{ 0(A`Ia
bStop = true; hu0z):>y
for(int i=0;i<nStartPos.length;i++) A@xa$!4}
fileSplitterFetch.splitterStop(); ;`',M6g
F7lhLly
SYd4 3PA
} U/9xO"b{.
} 68JYA?
//负责部分文件的抓取 d\dh"/_$
**FileSplitterFetch.java WG>Nm89
*/ lYldq)qB{
package NetFox; -qaJ@T+J+7
5H#f;L\k
\=PnC}7I
import java.io.*; }M-^A{C\%
import java.net.*; {Qbg'|HO=l
7{>mm$^|V
<5(P4cm9
public class FileSplitterFetch extends Thread { _0dm?=
_|reo6
VWf&F`^B(
String sURL; //File URL 9`
long nStartPos; //File Snippet Start Position NQ~keN
long nEndPos; //File Snippet End Position 5e=9~].7
int nThreadID; //Thread's ID S?ELFq(g
boolean bDownOver = false; //Downing is over 3y?I^ .B
boolean bStop = false; //Stop identical 4{4VC"fa
FileAccessI fileAccessI = null; //File Access interface cB#5LXbCE
*P2_l Q=
y(/"DUx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Kab"r_'
{ Qc1NLU9:
this.sURL = sURL; KSkT6_<
this.nStartPos = nStart; +*&bgGhT
this.nEndPos = nEnd; pFb}5Q
nThreadID = id; __N< B5E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VbX+`CwH
} [w*YH5kX
art L
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public void run() Ug(;\*yg
{ U4;r.#qw,
while(nStartPos < nEndPos && !bStop) APY^A6^:j
{ ;PM(q<@\
&[71~.Od
K|[p4*6
try{ D>tex/Of3
URL url = new URL(sURL); ,5}%_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @p`*MWU
httpConnection.setRequestProperty("User-Agent","NetFox"); fNR2(8;}
String sProperty = "bytes="+nStartPos+"-"; q,S[[{("
httpConnection.setRequestProperty("RANGE",sProperty); -;]m4R)z
Utility.log(sProperty); KA~eOEjM
LF6PKS
[0vgA#6I
InputStream input = httpConnection.getInputStream(); *Rm"3S
//logResponseHead(httpConnection); ws}cMX]*
Xa o*h(Q@L
,', S
byte[] b = new byte[1024]; )B"k;dLm
int nRead; W^dk:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) })#VO-J
{ T($d3Nn1
nStartPos += fileAccessI.write(b,0,nRead); 4mHR+SZy
//if(nThreadID == 1) V9KI?}q:W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5PF?Eq
} 0PdeK'7
E3..$x-/
M9[52D!{
Utility.log("Thread " + nThreadID + " is over!"); 7Yv1et |
bDownOver = true; rgq~lZ.U4K
//nPos = fileAccessI.write (b,0,nRead); Qc4r?7S<
} @QOlo-u
catch(Exception e){e.printStackTrace ();} 1f}YKT
} ZVu_E.4.
} QjT$.pUd
f6/<lSoW
BQWhTS7
//打印回应的头信息 yV"k:_O{
public void logResponseHead(HttpURLConnection con) r_R(kns
{ xA7>";sla[
for(int i=1;;i++) (U_`Q1Jo
{ vbA<=V*P
String header=con.getHeaderFieldKey(i); Kd='l~rby
if(header!=null) "Y'MuV'x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >T{Gl/? p
Utility.log(header+" : "+con.getHeaderField(header)); M[eq)a$
else 3{:AG,G
break; Y5mQY5u|
} jpwR\"UJ
} ;*{"|l qe
qb$&BZj]|
T'^ Do/
public void splitterStop() ) |t;nK,
{ y<9' 3\
bStop = true; 8Cx6Me>,=
} lL\%eQ
>b;o&E`\
4*0C_F@RX
} sA(d_Yu_
wak:"B[
jmORKX+)
/* ?T1vc
**FileAccess.java qg2fTe
*//文件访问(定位，写) og[cwa_
package NetFox; % _.kd"
import java.io.*; Bm>>-nG;
rtSG-_[i
;OMR5KAz
public class FileAccessI implements Serializable{ !k3 eUBF
cy-o@U"s8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $.+_f,tU
RandomAccessFile oSavedFile; kuq&8f~!
long nPos; 2`'g 9R
~:krJ[=
qkbGM-H%U
public FileAccessI() throws IOException zH5pe
{ n2V $dF4m
this("",0); #"qP4S2
} N%f% U
n 9>**&5L
C^IPddw>
public FileAccessI(String sName,long nPos) throws IOException W5*Kq^6Pd
{ b)+;=o%
oSavedFile = new RandomAccessFile(sName,"rw"); w!%"b03q
this.nPos = nPos; 4j1$1C{
oSavedFile.seek(nPos); Wa5B;X~
} \:BixBU7
\; voBU
eae`#>XP
public synchronized int write(byte[] b,int nStart,int nLen) ^j!2I&h1
{ h}y]Pt?
int n = -1; Zxw cqN
try{ ^7Rc\
oSavedFile.write(b,nStart,nLen); Yi?v|H<a
n = nLen; 5i@WBa
} 9,?7mgZp
catch(IOException e) 1j*E/L
{ y3 "+4e
e.printStackTrace (); 5La' I7q
} `nCVO;B
eH_< <Xh!v
XfQK kol
return n; J))U YJO
} fi~jT"_CI
,W|cyQ
$L4h'(s
} rT|wZz9$@
gF>t+"+x
im3BQIPR
/* 4%$#
**SiteInfoBean.java it$w.v+W7V
*/ } *jmWP
package NetFox; +;ylld
I=pFGU
|s'5~+
public class SiteInfoBean { i7b^b>B|e
8|{d1dy
ri/CLq^D
private String sSiteURL; //Site's URL dw>1Ut{"3
private String sFilePath; //Saved File's Path P:>]a$Is
private String sFileName; //Saved File's Name 5S*aZ1t18
private int nSplitter; //Count of Splited Downloading File 5m yQBKE
MW2{w<-]7
Qt\^h/zjG
public SiteInfoBean() /o^/J~/3
{//nSplitter的缺省值为5 "-Yj~
//default value of nSplitter is 5 z5J$".O`
this("","","",5); (nwp s
} @R_ON"h
.(7m[-iF!
+a"f)4\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O+?vQ$z
{ 3wMnTT"At
sSiteURL= sURL; LP'wL6#
sFilePath = sPath; `^HK-t4q
sFileName = sName; ]1 jhy2j
this.nSplitter = nSpiltter; \4KV9wm
aH_0EBRc
+i~kqiy.
} T0{X,
aHdQi,=z
h0?w V5H
public String getSSiteURL() W2&(:C8V@
{ \30rF]F`l
return sSiteURL; N/zP!%L
} d"tR?j
l<;~sag
z?@N+||,.
public void setSSiteURL(String value) Nt|Fw$3*5{
{ *\Lr]6k
sSiteURL = value; :O7n*lwx
} je`Inn<
Ro_jfM
\hWac%#
public String getSFilePath() -zzoz x]S=
{ %NDr5E^cc
return sFilePath; ,h9?o
} _C)\X(;
3lTnfc&
&x\cEI)!
public void setSFilePath(String value) 4t-l@zFWb
{ [V_+/[AA)
sFilePath = value; Q-7L,2TL
} i<(~J4}b
NwVhJdo
]=p^32
public String getSFileName() BV6B:=E0
{ $*:g~#bh
return sFileName; N@Q_5t0bk
} a2[rY
e{H(
n]6-`fpD
public void setSFileName(String value) #-o 'g!
{ T!I3.
sFileName = value; +KaVvf
} g4y&6!g
R9Y@I
+sV~#%%
public int getNSplitter() !;4Hh)2
{ <I#M^}`
return nSplitter; +`iJ+
} H>Ucmd;ay
dUUg}/
' &3,qT
public void setNSplitter(int nCount) wD:2sri
{ :cf#Tpq"
nSplitter = nCount; r@}8TE*|P
} FU(2,Vl
} Ylyk/
xS:n
0cDP:EzR;
/* RL)~J4Y
**Utility.java 8rjD1<
*/ tyWDa$u,u
package NetFox; d0i|^
lwz\"8
a;v4R[lQ
public class Utility { F+ 7*SImv6
$fBj}\o
h?H|)a<^9
public Utility() $wn0oIuW
{ [k0/ZfFwV
vvu $8n
M ziOpraj
} Wffz&pR8
&E1m{gB(
//线程睡眠 Y;'SD{On
public static void sleep(int nSecond) $}'(%\7"
{ ~4|Trz2T
try{ 'c_K[p$
Thread.sleep(nSecond); 5fMlOP_
} Pf/8tXs}
catch(Exception e) 0yvp>{;p
{ CB X}_]9X
e.printStackTrace (); 1+Uem
} 1J72*`4OK
} S;y4Z:!
E[6:}z<
//日志 >t<\zC|~w
public static void log(String sMsg) r6R@"1/
{ c-v-UO%
System.err.println(sMsg); RehraY3q
} B=$O4nW_b
?20R\ ]U
$7ix(WL<%
public static void log(int sMsg) HOF=qE*p
{ =LODX29
System.err.println(sMsg); I!Z"X&
} i(OeE"YA
} 6B% h
!A1~{G2VL_
z[ 'G"yCi
/* $PI9vyS
**TestMethod.java YRCs&tgs
*/ mU~&oU
package NetFox; nI&p.i6
,tcUJ}l
89;@#9
public class TestMethod { 6Ol9P56j
H9PnJr8 \
0:>hK\F#
public TestMethod() X:I2wJDs\
{ ///xx/weblogic60b2_win.exe jr_z ?
try{ f0j]!g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "*.N'J\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }r!+wp
SiteFileFetch fileFetch = new SiteFileFetch(bean); t=xEUOQAn
fileFetch.start(); qTN%9!0@9
} 9(nq 4HvI
catch(Exception e){e.printStackTrace ();} ,lStT+A
,i??}Wm5G
.}v" `>x
} T1*.3_wtP
lixM0
cJv/)hRaz
public static void main(String[] args) {=?(v`88
{ *coUHbP9>
new TestMethod(); AWYlhH4c?t
} >;'0ymG.`
} P"l'? `
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