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)); Q1T@oxV
} A?,A(-0C
for(int i=0;i<nEndPos.length-1;i++) O,irpQ
{ IT&i,`cJ~F
nEndPos = nStartPos[i+1]; 6pm~sD
} +NR n0 z(
nEndPos[nEndPos.length-1] = nFileLength; =<.F3lo\s
} ]EN&SWh
} uA%Ts*aN
t7^D-l
u]bz42]
//启动子线程 sUciFAb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iaRR5D-
for(int i=0;i<nStartPos.length;i++) L[]BzsIv
{ VYigxhP7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |X3">U +-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mPG7Zy$z
nStartPos,nEndPos,i); ls @5^g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I4~^TrznRa
fileSplitterFetch.start(); ?!7 SzLll
} ! Rvn'|!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <\ETPL,<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5#!ogKQ(i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r0Z+RB^I
nEndPos = " + nFileLength); Ux_<d?p
// fileSplitterFetch[nPos.length-1].start(); L|J~9FM
SUu >6'LN
MA6P"?
//等待子线程结束 [+gzdLad
//int count = 0; rS,j;8D-
//是否结束while循环 ]1}h8/
boolean breakWhile = false; t'aSF{%
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L#ZLawG
while(!bStop) ,CKvTxz0
{ c'rd$
write_nPos(); ytz8=\p_b
Utility.sleep(500); $T/#1w P
breakWhile = true; }4vjKSV
#>bT<
T.2ZBG~|[
for(int i=0;i<nStartPos.length;i++) y\Dn^
{ @'gl~J7
if(!fileSplitterFetch.bDownOver) e?=elN
{ "Z~`e]>
breakWhile = false; v:A:37#I
break; [TEcg^
} LU(%K{9
} 8f-:d]
if(breakWhile) j6og3.H-
break; Y}/c N\
@'HT;Q!\Vd
IfB/O.;Kz
//count++; uS-3\$
//if(count>4) x< S\D&
// siteStop(); NQR^%<hU
} N]u2ql&
K7Gm-=%
e`AUYli"
System.err.println("文件下载结束！"); Yw[{beo
} }!=U^A)
catch(Exception e){e.printStackTrace ();} 3SFg#
} >fbo r'|
M8zE3;5
_NT[ ~M_Q
//获得文件长度 K%PxA#P}
public long getFileSize() ]?# #))RUS
{ EZ{/]gCK
int nFileLength = -1; 7t3X`db
try{ |lE-&a$xd
URL url = new URL(siteInfoBean.getSSiteURL()); VWD.J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bKByU{t
httpConnection.setRequestProperty("User-Agent","NetFox"); )2]a8JVf
Gql`>~
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int responseCode=httpConnection.getResponseCode(); 9N1#V K
if(responseCode>=400) (Xj.iP
{ 8H_l[/
processErrorCode(responseCode); @`Wt4<
return -2; //-2 represent access is error ,02w@we5
} 6J"(xT
%Gu][_.L
f,JX"
String sHeader; C/y(E|zC$
(FG^UA#'
Y-= /,
for(int i=1;;i++) ;.AV;C"
{ egWx9xX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `{<JC{yc?
//Utility.log(in.readLine()); D!/0c]"
sHeader=httpConnection.getHeaderFieldKey(i); sNf +lga0
if(sHeader!=null) @sdS0pC
{ aH
if(sHeader.equals("Content-Length")) ^ `je
{ ?y46o2b*)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1xIFvXru
break; ~hzEKvs
} Wxc^_iqA1
} ,0h3x$l)
else La]4/=a
break; $Ba`VGP>)3
} +xq=<jy
} ,$ mLL
catch(IOException e){e.printStackTrace ();} ^1Yo-T(R
catch(Exception e){e.printStackTrace ();} :cb[M5c
4]]b1^vVj
fSr`>UpxC
Utility.log(nFileLength); aTX]+tBoe
}I)z7l.
*.xZfi_|
return nFileLength; VT Vm7l
} x~nQm]@`h
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TRo4I{L6S
//保存下载信息（文件指针位置） zaBG=
private void write_nPos() P.!;Uf}32
{ xp(mB7;:
try{ K: 4P;ApI
output = new DataOutputStream(new FileOutputStream(tmpFile)); OK.-]()!
output.writeInt(nStartPos.length); K# /Ch5?
for(int i=0;i<nStartPos.length;i++) {aT92-D3
{ +*<K"H|,
// output.writeLong(nPos); !}y8S'Yjw
output.writeLong(fileSplitterFetch.nStartPos); sC9-+}
output.writeLong(fileSplitterFetch.nEndPos); YyG~#6aCh
} _m" ^lo
output.close(); 1BTgGF
} |KTpK(6p
catch(IOException e){e.printStackTrace ();} (5>{?dR)|
catch(Exception e){e.printStackTrace ();} B JU*`Tx
} tjt=N\;
UJ O]sD`i
xTGP
//读取保存的下载信息（文件指针位置） !\3}R25
private void read_nPos() 1O|RIv7F[/
{ JtThkh'-"
try{ 7G?Ia%u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); < rv1IJ
int nCount = input.readInt(); Pb*q;9
nStartPos = new long[nCount]; bU:V%B?=]
nEndPos = new long[nCount]; t]gq+ c Lo
for(int i=0;i<nStartPos.length;i++) Ja^7$WY
{ {jrZ?e-q
nStartPos = input.readLong(); ^Kb9@lz/
nEndPos = input.readLong(); 5f/@:~
} C:WtCAm(
input.close(); \YjB+[.
} >t2]Ssi(
catch(IOException e){e.printStackTrace ();} "9TxK6
catch(Exception e){e.printStackTrace ();} PXOq#
} t%0r"bTi
aB/{ %%o
yLV2>kq
private void processErrorCode(int nErrorCode) nLzX Z6JlU
{ b/T20F{W\o
System.err.println("Error Code : " + nErrorCode); ~+7ad$
} h4J{jh.
ViCg|1c
tU8g(ep,o
//停止文件下载 2O}s*C$Xav
public void siteStop() }G"r3*
{ 41P4?"O
bStop = true; i528e{&
for(int i=0;i<nStartPos.length;i++) p,3go[9X:R
fileSplitterFetch.splitterStop(); ^yzo!`)fso
fRZUY<t
2&zn^\%"
} oHYD_8'f
} azz#@f1
//负责部分文件的抓取 CpBQ>!CW
**FileSplitterFetch.java COxZ Q
*/ IMl9\U
package NetFox; xCDA1y;j
2@"0}po#
HV#?6,U}
import java.io.*; 03i?"MvNo
import java.net.*; (cPeee%Q
;'b!7sMO~
U*`
public class FileSplitterFetch extends Thread { 9Bbm7Gd
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4\ uZKv@,
String sURL; //File URL $1Q3Y'Q9
long nStartPos; //File Snippet Start Position )]0[`iLe
long nEndPos; //File Snippet End Position 'l0eo' K
int nThreadID; //Thread's ID -eSPoZ
boolean bDownOver = false; //Downing is over H|UV+Q0,
boolean bStop = false; //Stop identical e+d6R[`M
FileAccessI fileAccessI = null; //File Access interface ~T;ajvJ
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u"Hd55"&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y_|K,T6Zj@
{ "63zc1
this.sURL = sURL; 2V=FWuXC"
this.nStartPos = nStart; j?Jd@(*y$
this.nEndPos = nEnd; s)`1Rf
nThreadID = id; .MzP}8^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p;c_<>ws-Y
} ],fwZd[t
@+T{M:&l
3;-@<9
public void run() h[[/p {z
{ %$9)1"T0Y
while(nStartPos < nEndPos && !bStop) {Vt^Xc
{ K{r1&O>W
6qHvq A,
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try{ x1&b@u
URL url = new URL(sURL); ]Gi+Z1q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !Xv2PdP
httpConnection.setRequestProperty("User-Agent","NetFox"); 6\S$I5
String sProperty = "bytes="+nStartPos+"-"; ]<o.aMdV
httpConnection.setRequestProperty("RANGE",sProperty); j4 &
Utility.log(sProperty); t3yQ/
4E>/*F!
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InputStream input = httpConnection.getInputStream(); "k_n+cH%
//logResponseHead(httpConnection); EU&3Pdnd
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71n uTE%!
byte[] b = new byte[1024]; O>"r. sR
int nRead; lJz?QI1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e$xv[9
{ *F%ol;|Q
nStartPos += fileAccessI.write(b,0,nRead); uYFcq
//if(nThreadID == 1) t$PnQ@xu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >I8hFtAM
} UV *tO15i
E't G5,/m
%]:vT&M
Utility.log("Thread " + nThreadID + " is over!"); ;P0Y6v3
bDownOver = true; =ZJ?xA8
//nPos = fileAccessI.write (b,0,nRead); g]PLW3
} 2I(@aB+
catch(Exception e){e.printStackTrace ();} lh(+X-}D
} Cak/#1
} (a)@<RF`Q}
as\K(c9
V]S06>P
//打印回应的头信息 >"$-VY6i
public void logResponseHead(HttpURLConnection con) !k??Kj
{ B+q+)O+
for(int i=1;;i++) '14l )1g.
{ ;x0KaFk
String header=con.getHeaderFieldKey(i); +n.j.JP"X
if(header!=null) VL!kX``^F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d(B;vL@R2V
Utility.log(header+" : "+con.getHeaderField(header)); !L.z4n,n+
else t-|=weNy
break; *y\tnsU
} bHH}x"d[x
} .2SIU4[P
fdEj#Ux<H
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public void splitterStop() /a/uS3&
{ yar IR|
bStop = true; }lvP|6Y: y
} _itN.^
)Jjw}}$}Y
xXh]z|
} z^GGJu%vjr
(i~%4w=
:Y?08/V
/* *l8vCa9Y
**FileAccess.java JI; i1@|b
*//文件访问(定位，写) ?*5l}y=
package NetFox; OZ]3OL,
import java.io.*; s#Y7*?Sm
T-cVM>u\D
l:C0:m%
public class FileAccessI implements Serializable{ 2{tJ'3
W p* v Vv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (#Kvm
RandomAccessFile oSavedFile; aj-uk(r
long nPos; iQR})=Q
Fi=8B&j
b,V=B{(~
public FileAccessI() throws IOException &T.P7nJ=
{ T`DlOi]Z_
this("",0); -Z&{$J
} p2?+[d
]6 7wk
lMf5F8
public FileAccessI(String sName,long nPos) throws IOException 'WgwLE_
{ vPq\reKe
oSavedFile = new RandomAccessFile(sName,"rw"); ] ]-0RJ=S?
this.nPos = nPos; z4UQ:z@
oSavedFile.seek(nPos); qq{N; C
} P@![P Ij
kqB00 ;
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public synchronized int write(byte[] b,int nStart,int nLen) 8LKZ3Y|
{ ;lt;]7
int n = -1; VDN]P3
try{ } dlNMW
oSavedFile.write(b,nStart,nLen); cO+`8`kv
n = nLen; bW3o%srxa
} vw 2@}#\:
catch(IOException e) DKCy h`
{ 6>A8#VT
e.printStackTrace (); /;ITnG
} a'~y'6
mMWNUkDq
GlZDuU
return n; kniMXeiu
} #8|NZ6x,
l.)!jWY
)gF9D1eA
} r!uAofIi_
FvP1;E
;OyM~T gI
/* 0:8'Ov(
**SiteInfoBean.java %>z}P&Yz
*/ p}z0(lQ*~
package NetFox; Pl6=._
s[bKGn@
R[t[M}q
public class SiteInfoBean { ?[">%^
u] b6>
3!x)LUWfWY
private String sSiteURL; //Site's URL "de:plMofy
private String sFilePath; //Saved File's Path ?H?r!MZ%
private String sFileName; //Saved File's Name eu;^h3u;b
private int nSplitter; //Count of Splited Downloading File `#bcoK5
WGn1pW
ZC-N4ESr
public SiteInfoBean() w6 .HvH-@?
{//nSplitter的缺省值为5 7h~M&\M
//default value of nSplitter is 5 yhmW-#+^e
this("","","",5); &jcr7{cD
} ZAwl,N){
k,& QcYw
2F(j=uV+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mt`.|N;y!
{ |/$#G0X;H
sSiteURL= sURL; ?K"]XXsI
sFilePath = sPath; E*vi@aI
sFileName = sName; ^;d;b<
this.nSplitter = nSpiltter; 5KzU&!Zh9
S;~_9i]upe
COafVlJ,l
} W0k_"uI
B7;MY6h#
,*30Q
public String getSSiteURL() "(xu
{ c9@*
return sSiteURL; z,WrLZC
} <:w7^m
A@+.[[
qI}Zg)q]
public void setSSiteURL(String value) joq ;N]S
{ 6._):[_2
sSiteURL = value; 2Xosj(H
} )XFMlSx)
u CXd% CzE
:([,vO:
public String getSFilePath() Lfor0-j
{ eYFCf;
return sFilePath; KH-.Z0 2U
} W+vm!7wX0
Z:}^fZP
a%kj)ah
public void setSFilePath(String value) <[Vr(.A
{ 8}&cE#@
sFilePath = value; h!MT5B)r.
} `?:'_Ki
-Ac^#/[0
tB[K4GNSQ
public String getSFileName() r*Mm5QozA
{ iZUBw
return sFileName; ]TQjk{X<
} =vWnqF:
DE[y&]/C{
u^uW<.#z
public void setSFileName(String value) *m7e>]-
{ /Wa+mp
sFileName = value; W$y?~2
} WJ%b9{<
WrV|<%EQh
*oF{ R^
public int getNSplitter() !vU[V,~
{ |:AjQ&PM)
return nSplitter; 0Bll6Rd
} (mzyA%;W
]b[3 th*
87-oR}/r
public void setNSplitter(int nCount) 90q*V%cS
{ !U91
nSplitter = nCount; yO !*pC
} tlW}lN}
} ALG +
vK$W)(Z
Fax73vl|^a
/* %c&h:7);
**Utility.java aW"BN 5eM>
*/ }5A?WH_
package NetFox; hfY2pG9N
B%,0zb+-L
<fP|<>s$@1
public class Utility { R_-.:n%.z
{P*RA'H3G
O)hNHIF
public Utility() v"^G9u
{ U+\\#5$
:/u EPki
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} /u?^s "C/
?O28Q DUI
//线程睡眠 |kjk{
public static void sleep(int nSecond) }^=J]
{ M]oaWQu
try{ F&ux9zP
Thread.sleep(nSecond); ,Q^.SHP8
} IF<jq\M
catch(Exception e) w'}b 8m(L
{ 5Ba eHzI
e.printStackTrace (); D&.+Dx^G
} 0PZpE "$X
} emTqbO
6<gh:vj
//日志 9OX&;O+5
public static void log(String sMsg) X'O3)Yg
{ KZ&{Ya
System.err.println(sMsg); V4_ZBeWA
} WxFVbtw
+dlN^P647
iOw'NxmY
public static void log(int sMsg) Zhf+u r
{ "HlT-0F
System.err.println(sMsg); 0ZTT^2R
} 7V?TLGgd$
} wgY:W:y'N
jruwdm^
SIVzc Hm
/* \Gg6&:Ua
**TestMethod.java [8[g_
*/ `C$.
package NetFox; M/T ll]\|
Kx7s d i
r761vtC#
public class TestMethod { C`Zz\DNG@
"|`euxYV
'_>8_
public TestMethod() 741Sd8
{ ///xx/weblogic60b2_win.exe wX[g\,?}'
try{ 3,t3\`=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^z)p@sk#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .]24V!J(1w
SiteFileFetch fileFetch = new SiteFileFetch(bean); DgW*Br8<
fileFetch.start(); m5`<XwD9
} ^\KZE|^3@
catch(Exception e){e.printStackTrace ();} o!bV;]
^zn&"@
jnho*,X
} $bOiP
b@`h]]~:
it77x3Mm F
public static void main(String[] args) opqY@>Vh&
{ ebfT%_N
new TestMethod(); ZOw%Fw4B
} ~>SqJ&-moo
} d;@"Naw
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