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)); v @N8v
} KQ9:lJKr
for(int i=0;i<nEndPos.length-1;i++) G:e}>'
{ 3^su%z_%
nEndPos = nStartPos[i+1]; IB*%PMTF
} U0N[~yW(t1
nEndPos[nEndPos.length-1] = nFileLength; ]aakEU
} d=4MqX r
} uV 6f~cQ
cW GU?cv}
j^!J:Bj
//启动子线程 ) L{Tn8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {U(h]'
for(int i=0;i<nStartPos.length;i++) S5Px9&N8(
{ tc,7yo\".
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 329xo03-[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )sS<%Xf
nStartPos,nEndPos,i); @e0Q+t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $0W0+A$
fileSplitterFetch.start(); 'b^:"\t'Rh
} t=e0z^2i+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2iG(v._x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $z,bA*j9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -owfuS?i=
nEndPos = " + nFileLength); #i]@"R
// fileSplitterFetch[nPos.length-1].start(); }> 1h+O
ev guw*u
yauP j&^R
//等待子线程结束 eO9nn9lql
//int count = 0; g*tLqV
//是否结束while循环 1VZ>*Tl
boolean breakWhile = false; <?J7Z|
9H)uTyuNi
b{dzbmak
while(!bStop) OVh/t#On
{ ``E;!r="v
write_nPos(); fVN}7PH7+
Utility.sleep(500); i ('EBO
breakWhile = true; =4%C?(\
yED^/=\)}
RU>vnDaC
for(int i=0;i<nStartPos.length;i++) {oJa8~P
{ V[bc-m
if(!fileSplitterFetch.bDownOver) \S@A /t6pa
{ k?8W2fC
breakWhile = false; ) k2NF="o
break; JZnWzqFw
} 0Its;|
} mcXakWmi
if(breakWhile) 'OihA^e
break; 7S7!
Y}#^n7*w~
|zT0g]WH
//count++; i-=ff
//if(count>4) y;>I'e
// siteStop(); !fV6KkV
} :hr@>Y~r
k2WO*xa*
xXYens}
System.err.println("文件下载结束！"); B*AMo5
} R`?^%1^N
catch(Exception e){e.printStackTrace ();} 6;b 'j\jG
} [;2:lbPx
[O)Zof
;VH]TKkk
//获得文件长度 jlP7'xt1%
public long getFileSize() ,qHG1#^
{ xq)/QR
int nFileLength = -1; _NZHrN
try{ A-u5
URL url = new URL(siteInfoBean.getSSiteURL()); =iQm_g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W.R'2R#
httpConnection.setRequestProperty("User-Agent","NetFox"); Rp|&1nS
U;xWW9
&;skB.
int responseCode=httpConnection.getResponseCode(); ^0 lPv!2
if(responseCode>=400) k$ M4NF~$
{ @~XlI1g$i
processErrorCode(responseCode); ,+BgY4OY
return -2; //-2 represent access is error &}$D[ 4N
} eEh0T%9K
&aQ)x
7EO&:b]
String sHeader; DnFl*T>
q{ 1U
Pb;`'<*U
for(int i=1;;i++) F)5Aq H/p
{ n6Zx0ad?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o5@ jMU;
//Utility.log(in.readLine()); y m{/0&7
sHeader=httpConnection.getHeaderFieldKey(i); ~b[4'm@
if(sHeader!=null) O*v+<|0!l
{ M!l5,ycF
if(sHeader.equals("Content-Length")) mwCnP8:K
{ e;'T?&t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T!A}ipqb
break; v`w?QIB]
} L _y|l5
} Lp WEu^j
else L# 1vf
break; S:uEK
} SkA'+(
} x=#5\t9
catch(IOException e){e.printStackTrace ();} .8!0biS
catch(Exception e){e.printStackTrace ();} {wXN kq
$:N "*
hNo>)$v!s
Utility.log(nFileLength); _q_[<{#
O*{H;7Pv
PI \,`^)y
return nFileLength; o#) !b:/
} L,pSdeq
<xjv7`G7
xm0#4GFUS
//保存下载信息（文件指针位置） J-<B*ot+lX
private void write_nPos() B[B<U~I}
{ \=V[ba:q
try{ cgeS)C7
output = new DataOutputStream(new FileOutputStream(tmpFile)); Le JlTWotC
output.writeInt(nStartPos.length); f{c[_OR
for(int i=0;i<nStartPos.length;i++) :*'?Ac ?
{ :+Ax3
// output.writeLong(nPos); gtGKV
output.writeLong(fileSplitterFetch.nStartPos); faOWhIG
output.writeLong(fileSplitterFetch.nEndPos); AJd.K'=8
} -*fYR#VQQB
output.close(); si_HN{
} gA1in
catch(IOException e){e.printStackTrace ();} 5l/l]
catch(Exception e){e.printStackTrace ();} G)Bq?=P
} 6CmFmc,
U hhmG+
XWQ0V
//读取保存的下载信息（文件指针位置） o=# [^Zv
private void read_nPos() }cej5/*
{ b]&zDo|8
try{ ?mR[A`J58
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $jh>zf
int nCount = input.readInt(); )9*3^v
nStartPos = new long[nCount]; gNN" H#=2
nEndPos = new long[nCount]; Q9xx/tUW
for(int i=0;i<nStartPos.length;i++) )$h9Y
{ U"Hquo
nStartPos = input.readLong(); 3t{leuO'
nEndPos = input.readLong(); PbHh?iH
} M .`
input.close(); WTYFtZD[yH
} |kNGpwpI
catch(IOException e){e.printStackTrace ();} ^r_lj$:+$
catch(Exception e){e.printStackTrace ();} LA`VqJ
} [ky6E*dV`
![]I%'s
)c >B23D
private void processErrorCode(int nErrorCode) /+t[,
{ &:I +]G/W
System.err.println("Error Code : " + nErrorCode); kF,\bM
} =&VXn{e
:t{vgi D9
}R&5qpl
//停止文件下载 ]z=Vc#+!
public void siteStop() ?g;ZbD
{ pl,Z
bStop = true; n`z+ w*
for(int i=0;i<nStartPos.length;i++) &:CjUaP@
fileSplitterFetch.splitterStop(); >-@ U_p
CCh8?sM
e_c;D2'F
} fTHun?Vn
} }j(2Dl
//负责部分文件的抓取 .`&/QiD
**FileSplitterFetch.java 1uS-Tx
*/ k gu[!hD1
package NetFox; nlebFDb7
(5q%0|RzRs
M1^C8cz
import java.io.*; soq".+Q
import java.net.*; %L13Jsw
l \^nC2
+Sd,l>8\
public class FileSplitterFetch extends Thread { G(0y|Eq
i`KZ,
Ryq"\Q>+
String sURL; //File URL 4SffP/
long nStartPos; //File Snippet Start Position -yAnn
long nEndPos; //File Snippet End Position fEw=I7{Y
int nThreadID; //Thread's ID ^'[@M'`~L
boolean bDownOver = false; //Downing is over $C05iD
boolean bStop = false; //Stop identical L=HVdeE
FileAccessI fileAccessI = null; //File Access interface |^PLZ>
sjzXJ`s
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6Z7pztk
{ N~$Zeq=
this.sURL = sURL; G4`Ut1g^
this.nStartPos = nStart; ytve1<.Ff
this.nEndPos = nEnd; hiMyFvA4
nThreadID = id; 5M Wvu,'%8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .^LL9{?
} q^N0abzgP
;sChxQ=.^
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public void run() WR a+zii,
{ Itr7lv'5xx
while(nStartPos < nEndPos && !bStop) {x|kg;
{ E./__Mz@
'>e79f-O)
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try{ zvGK6qCk
URL url = new URL(sURL); TsX+. i'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <4Q12:
httpConnection.setRequestProperty("User-Agent","NetFox"); !b7'>b'J<1
String sProperty = "bytes="+nStartPos+"-"; m(Y.X=EZr
httpConnection.setRequestProperty("RANGE",sProperty); -jVaS wt
Utility.log(sProperty); Be{/2jU%
Cfr<D3&,]
JEsLF{
InputStream input = httpConnection.getInputStream(); ;wbUk5Tf/
//logResponseHead(httpConnection); \oB'
M20Bc,VI
z9M.e.
byte[] b = new byte[1024]; i-k >U}[%
int nRead; t$K@%yU2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SH vaV[C
{ f]ue#O
nStartPos += fileAccessI.write(b,0,nRead); _V& !4Zd9:
//if(nThreadID == 1) ;v1NL@w*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `c'
} $U>/i@D
v]:+`dV
;+i'0$;*w
Utility.log("Thread " + nThreadID + " is over!"); DikdC5>O>m
bDownOver = true; TX23D)CX
//nPos = fileAccessI.write (b,0,nRead); xJ~ gT
} `S\zqF<
catch(Exception e){e.printStackTrace ();} .kc"E
} -^iUVO`z
} $Ns,ts(ng
rBD(2M
AfRW=&xdT
//打印回应的头信息 X&(<G
public void logResponseHead(HttpURLConnection con) N-2([v
{ FjZc#\^9
for(int i=1;;i++) E.J0fwyT
{ `ke3+%uj o
String header=con.getHeaderFieldKey(i); 9c6czirwR^
if(header!=null) skIiJ'db
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bo@,4xw
Utility.log(header+" : "+con.getHeaderField(header)); ~+N76BX
else *;hY.EuoFz
break; (*6m^
} p^1zIC>F
} PS=e\(6QC
#wenX$UTh3
S\e&?Y`
public void splitterStop() qKdS7SoS
{ N0Efw$u
bStop = true; Vi|7%!j<
} HDmx@E.@
M18qa,fK{
+Edzjf~Tt
} /gz:zThf{
G'f9N^w
<4bz/^
/* j8GY`f#
**FileAccess.java E6Q]A~
*//文件访问(定位，写) A8pj~I/*-
package NetFox; :dP~.ZY7
import java.io.*; SY-ez91
i;o}o*=
mZ~qG5@/F
public class FileAccessI implements Serializable{ v6s\Z\v)Q`
:qKF58W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q!6|lZB3
RandomAccessFile oSavedFile; &]P"48NT
long nPos; nPcS3!7B#
i"vawxm
9!9> ?Z
public FileAccessI() throws IOException \dRzS@l
{ QyPg |#T2>
this("",0); X8/Tl\c
} ]3*P:$Rq
ha*X6R
~>V-*NT8
public FileAccessI(String sName,long nPos) throws IOException #s"851e
{ q|5Q?t:,r
oSavedFile = new RandomAccessFile(sName,"rw"); *>jjMyn
this.nPos = nPos; <i{K7}':
oSavedFile.seek(nPos); .xO _E1Ku;
} !;%y$$gxh
/XcDYMKgh
dY}pN"
public synchronized int write(byte[] b,int nStart,int nLen) |6E .M1
{ %*lp< D
int n = -1; aG%kmS&fv
try{ 5m4DS:&
oSavedFile.write(b,nStart,nLen); 3{"byfO#%
n = nLen; IU@_)I+6
} ?d$"[lKX
catch(IOException e) AoBoFZLl3
{ 9)`amhf>
e.printStackTrace (); }g`Gh|C
} 8L%M<JRg~
-hWC_X:9jP
;DuXSy!g
return n; [C1 LT2a
} bAf,aV/C&|
7+}JgUh
wtXY:O
} %Rp8{.t7
UVz/n68\k7
845 W>B
/* ?i~g,P]NK
**SiteInfoBean.java Cq>6rn
*/ < f(?T`
package NetFox; z{:-!oF&CB
f~=r*&U
X7aYpt;
public class SiteInfoBean { 62[8xn=(%
740B\pc0
GWsd| kxU
private String sSiteURL; //Site's URL {.st`n|xz
private String sFilePath; //Saved File's Path G"T\=cQz
private String sFileName; //Saved File's Name uWjN2#&,
private int nSplitter; //Count of Splited Downloading File fc@'9-pt
$X\va?(
["y6b*;x
public SiteInfoBean() fkjeR B
{//nSplitter的缺省值为5 nnwJYEi
//default value of nSplitter is 5 W|MWXs5'1*
this("","","",5); hN
} BOvF)4`
y,E.SB
s)zJT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }`xdWY
{ _;hf<|c
sSiteURL= sURL; OfTfNhpK
sFilePath = sPath; 5RF4]$zT
sFileName = sName; w(U:U-MNe
this.nSplitter = nSpiltter; A%u_&a}
3J~0O2
W@.Ji B
} 9sSN<7
=su]w2,Iy
.oqIZ\iik
public String getSSiteURL() hmpr%(c`
{ 5.vG^T0w
return sSiteURL; ,:)`+v<
} 1!1!PA9u
ZF6c{~D
Ipe n
public void setSSiteURL(String value) DkDoA;m
{ nv0#~UgE#a
sSiteURL = value; l30Y8t~d
} Qd]we$G
A#rh@8h+
:ofBzTNwZ
public String getSFilePath() ?A?F.n`
{ =Mj0:rW
return sFilePath; 8w_7O>9
} ***a2Z/(
uo2'"@[e
"l7NWqfB
public void setSFilePath(String value) aS84n.?vq
{ Io n~
sFilePath = value; NBYH;h P
} x|i_P|Z
-MBV$:_R
D`[Khsf
public String getSFileName() d$t40+v
{ DY\J[l<<
return sFileName; (UL4+ta
} t~``md4
DF_X
lk3=4|?zsE
public void setSFileName(String value) !4(zp;WY^
{ =>iA gp'#
sFileName = value; W/fuKGZi_
} jQ\zGJ3
QA3/
cl@g
public int getNSplitter() k^\pU\J
{ k&/OU:7Y
return nSplitter; .uF[C{RnO
} nXy>7H[0
Q>Qibr
"4o=,$E=
public void setNSplitter(int nCount) [sF(#Y:I
{ G2Vv i[c
nSplitter = nCount; P 43P]M2
} 0[Ht_qxb
} rx0~`cVV:
-' g*^
au7.4ln>Y
/* v&a4^s
**Utility.java q%Yn;g|_
*/ up>c$jJ
package NetFox; asHxL!
:,B7-kBw
X]%itA
public class Utility { *v ?m6R=)h
A A^{B
2ZcKK8X;7
public Utility() zK|i='XSf
{ 6eFp8bANN#
7aV%=_
<-'$~G j
} XI<L;
ag-f{UsTy
//线程睡眠 H@bf'guA|B
public static void sleep(int nSecond) nKa$1RMO
{ 2*w0t:Yxe
try{ Dre2J<QL
Thread.sleep(nSecond); 9KWuN:Sg
} ~6YMD
catch(Exception e) -m *Sq
{ Lk\P7w{
e.printStackTrace (); d.UQW yLG
} _g%TSumvq<
} B"yFS7Rrj
)R`xR,H
//日志 0:w"M<80
public static void log(String sMsg) eET&pP3Rp
{ AIMSX]m
System.err.println(sMsg); R^?/' dr
} 2c6g>?
#Cpd9|
@+3kb.P%7
public static void log(int sMsg) .p0Clr!
{ HY)-/
System.err.println(sMsg); v~QHMg
} L:XC
} X+UJzR90
*na?n2Yzt
A,sr[Pa@
/* V|(H|9
**TestMethod.java 8J$|NYv_b
*/ 9mA{K
package NetFox; jCbV,0)^
_SW3_8SuM.
;rc`OZyE
public class TestMethod { i&{DOI%w
k0Ol*L!p
-f*P nxg
public TestMethod() sMu] /'7
{ ///xx/weblogic60b2_win.exe ]a5 f2lE
try{ '%q$`KDb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (L^]Lk x)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S$QG.K:<!
SiteFileFetch fileFetch = new SiteFileFetch(bean); [w% qV 6
fileFetch.start(); eek7=Z
} |{CfWSB7~@
catch(Exception e){e.printStackTrace ();} 8Z(Mvq]f&
:q#Xq;Wp
6I@h9uIsze
} n{6G"t:^l
!pD*p)`s
BD(Z5+EU1
public static void main(String[] args) L4!{h|
{ ~\J}Kqg
new TestMethod(); tH-C8Qxy
} ,^uEYT}j
} RzWXKBI\E]
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