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)); :GN)7|:
} ~|X99?P
for(int i=0;i<nEndPos.length-1;i++) ODM>Z8@W/
{ 9)G:::8u7
nEndPos = nStartPos[i+1]; ,$hQ(yF
} SlH7-"Ag
nEndPos[nEndPos.length-1] = nFileLength; ,2=UuW"K
} ,m #@%fa
} ;s}-X_O<
x(C]O,
>xxXPvM<`
//启动子线程 0!3!?E <
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Da9*/
for(int i=0;i<nStartPos.length;i++) <wIp$F.
{ 6LSPPMM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \_iH4<#>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7VEt4
nStartPos,nEndPos,i); Ig40#pA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yrxx+z|wR
fileSplitterFetch.start(); 0hHIz4(
} m _t(rn~f6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |_Naun=+~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o'x_g^ Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nr'YWW
nEndPos = " + nFileLength); |YG)NO
// fileSplitterFetch[nPos.length-1].start(); "wc`fg"3
[15hci+-
b&hF')_UOz
//等待子线程结束 UiGUaBmF*
//int count = 0; ~G|{qVO7A
//是否结束while循环 '^P*F9
boolean breakWhile = false; Y\Fuj)
c]cO[T_gGa
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while(!bStop) j8D$/
{ z1}tC\9'%
write_nPos(); GI'&g@?u
Utility.sleep(500); F1Zk9%L%9$
breakWhile = true; 4fU5RB7%
1s^$oi}
D{&+7C:8.
for(int i=0;i<nStartPos.length;i++) L!G9O]WB
{ ^>P@5gcoE(
if(!fileSplitterFetch.bDownOver) -r6(=A
{ Ep v3/`I
breakWhile = false; <.y^
break; oKMg7 3*
} |-cALQ
} IdQwLt
if(breakWhile) NO0[`jy(
break; EmBfiuX
f:)K
D6pEQdX`
//count++; i?P]}JENM
//if(count>4) Z3u""oM/
// siteStop(); H|(*$!~e
} Y/:Q|HnXQ
Bv |jo&0n
K|Ij71
System.err.println("文件下载结束！"); *y[~kWI
} \8C*O{w
catch(Exception e){e.printStackTrace ();} ]0/~6f
} +Qb2LR
\fQgiX
1W6n[Xg
//获得文件长度 r*
public long getFileSize() sDh6 Uk
{ %_i0go,^
int nFileLength = -1; hQW#a]]V:
try{ x.yb4i=Jq
URL url = new URL(siteInfoBean.getSSiteURL()); `rOe5Zp$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;M(ehX
httpConnection.setRequestProperty("User-Agent","NetFox"); $48[!QE
i,U-H\p&
Y GcY2p<
int responseCode=httpConnection.getResponseCode(); !513rNO
if(responseCode>=400) tM?I()Y&P
{ FdK R{dX}
processErrorCode(responseCode); RIVN>G[;L
return -2; //-2 represent access is error e[py J.
} 5qODS_Eq
D$^7Xhk
!&`7
String sHeader; L>R!A3G1
-7A!2mRiz
(WU~e!}
for(int i=1;;i++) 5kL#V
{ qLktMp_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KG./<"c
//Utility.log(in.readLine()); Y;F,GxR}
sHeader=httpConnection.getHeaderFieldKey(i); >5z`SZf
if(sHeader!=null) G%x,t-
{ K+aJ`V
if(sHeader.equals("Content-Length")) Q*{H]
{ -iZjs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J~ gkGso
break; *dn-,Q%`
} 8aM% 9OU
} e715)_HD
else 66y,{t
break; W} +6L|
} oY#XWe8Om
} (UiH3Q9C]%
catch(IOException e){e.printStackTrace ();} g5TLX&Bd
catch(Exception e){e.printStackTrace ();} dT-O8
C(Bar#
@5nkI$>3z
Utility.log(nFileLength); q~A|R
uS+b* :
fqp7a1qQl
return nFileLength; (V|q\XS
} 0BU:(o&
*~aI>7H
CI]U)@\U
//保存下载信息（文件指针位置） AXv3jH,HF
private void write_nPos() qcoZ2VJ hh
{ Z(clw
try{ N`mC_)
output = new DataOutputStream(new FileOutputStream(tmpFile)); =P+wp{?AN|
output.writeInt(nStartPos.length); cH8H)55F
for(int i=0;i<nStartPos.length;i++) 0eu$oel-
{ =GS_ G;Dz
// output.writeLong(nPos); 74!JPOpQH
output.writeLong(fileSplitterFetch.nStartPos); uX5B>32
output.writeLong(fileSplitterFetch.nEndPos); x+j/v5
} 5D@Q1
output.close(); Q?'W >^*J
} &I">{J<
catch(IOException e){e.printStackTrace ();} oGjYCVc
catch(Exception e){e.printStackTrace ();} Y&Nv>o_}5
} Z-r0 D
gZuR4Ti
N pIlQaMo4
//读取保存的下载信息（文件指针位置） Fu=VY{U4
private void read_nPos() i3\oy`GJ
{ G}OrpPP
try{ ZCq\Zk1O&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mgl' d
int nCount = input.readInt(); 'k) P(H
nStartPos = new long[nCount]; 6Yi,%#
nEndPos = new long[nCount]; ZkG##Jp\>
for(int i=0;i<nStartPos.length;i++) 4w
{ SodW5v a
nStartPos = input.readLong(); ToCfLJ?{
nEndPos = input.readLong(); YH6K-}
} m3ZOq B-
input.close(); 91'^--N
} zCN;LpbEJY
catch(IOException e){e.printStackTrace ();} NomK(%8m$
catch(Exception e){e.printStackTrace ();} x-P_}}K 79
} ~1z8G>R
NxRiEe#m
1JY90l$ME
private void processErrorCode(int nErrorCode) t5[JN:an
{ J-,X0v"
System.err.println("Error Code : " + nErrorCode); J!qEj{
} @o.i2iG
.oOt(K+
}LVE^6zyk
//停止文件下载 WxI]Fcb<
public void siteStop() IQ`aDo-V
{ m<;" 1<k
bStop = true; o`]FH_
for(int i=0;i<nStartPos.length;i++) +Gs;3jC^
fileSplitterFetch.splitterStop(); H0:6zSsc=|
Kd21:|!t^
h!3Z%M
} 0>J4O:k
} 8TM=AV
//负责部分文件的抓取 K*D]\/;^
**FileSplitterFetch.java ^,r;/c9A8
*/ NWX%0PGZ
package NetFox; R3=E?us!
%Y[/Ucdm
DD3yl\#,
import java.io.*; Fgq*3t
import java.net.*; 8U$UI
~w%+y
w9}IM149
public class FileSplitterFetch extends Thread { W..>Ny;'3
3m9E2R,
.}opmI
String sURL; //File URL h*'5h!
long nStartPos; //File Snippet Start Position 2]KPW*V
long nEndPos; //File Snippet End Position 0To 5|r
int nThreadID; //Thread's ID v2<gkCK^
boolean bDownOver = false; //Downing is over MO+0]uh:
boolean bStop = false; //Stop identical Ft>8 YYyU
FileAccessI fileAccessI = null; //File Access interface l"g%vS,;`
;qQzF
D-EM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f)fw87UPc
{ eesLTyD2_
this.sURL = sURL; yr DYw T
this.nStartPos = nStart; |W[rywxx
this.nEndPos = nEnd; J@-9{<
nThreadID = id; tG&B D\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a,\u|T:g
} ;Q 6e&Ips/
p#NZ\qJ
ZSf+5{2m
public void run() *38\&"s4_
{ /v<8x?=
while(nStartPos < nEndPos && !bStop) 2,`mNjHh
{ ;hp; Rd
7hE=+V8
Jk{2!uP
try{ U}TQXYAg
URL url = new URL(sURL); wYM{x!D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p =O1aM
httpConnection.setRequestProperty("User-Agent","NetFox"); NX/)Z&Fx:
String sProperty = "bytes="+nStartPos+"-"; D~);:}}>
httpConnection.setRequestProperty("RANGE",sProperty); "Vy\-^
Utility.log(sProperty); P_%l}%
u>@G:kt8
%gB0D8,vo
InputStream input = httpConnection.getInputStream(); 'S>Jps@
//logResponseHead(httpConnection); _JB3+0@
Qk?Jy<Ra
=v;@w$#
byte[] b = new byte[1024]; 9&jNdB
int nRead; 3mpjSL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _3JTHf<+
{ W{2y*yqY
nStartPos += fileAccessI.write(b,0,nRead); .w"O/6."
//if(nThreadID == 1) M6n.uho/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DSa92:M}
} Z0^do
s_$@N!
VNfx>&`
Utility.log("Thread " + nThreadID + " is over!"); }7^*%$
bDownOver = true; jR:Fih-}
//nPos = fileAccessI.write (b,0,nRead); (CwaOm{g
} 6FAP *V;
catch(Exception e){e.printStackTrace ();} /zAx`H
} \|s/_35(
} `UPmr50Wq
;#
B 8,{jwB
//打印回应的头信息 4,8 =[
public void logResponseHead(HttpURLConnection con) j'cS_R
{ 1NJ|%+I
for(int i=1;;i++) 'JVvL
{ 3Q;l*xu
String header=con.getHeaderFieldKey(i); T!r7RS
if(header!=null) T9yW# .
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %UhF=C
Utility.log(header+" : "+con.getHeaderField(header)); G3n7x?4m
else s"Wdbw(O'
break; jiDYPYx;I
} F[Up
} m5*RB1
6IH^rSUSK
su$juI{
public void splitterStop() w0SgF/"@
{ z9ZAY!Zhq]
bStop = true; ;E_{Zji_e
} -0Ek&"=Z^
6cvm\opH
1:8: yFV
} 9IMcp~zX
e)8iPu ..
bv0 %{u&
/* I Cs1=
**FileAccess.java vhW'2<(
*//文件访问(定位，写) ?*0kQo'
package NetFox; agzG
import java.io.*; 7BnP,Nd"W
kzT'
a;sZNUSn
public class FileAccessI implements Serializable{ =r2d{
?auiq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fyeS)
RandomAccessFile oSavedFile; ]Ea6Z
long nPos; .nN7*))Fj
~%ZO8X:^
%K4-V5f
public FileAccessI() throws IOException iD~s,
{ hb{(r@[WHv
this("",0); kaLRI|hC
} L.'N'-BV
l/5/|UE9
`N0E;=g
public FileAccessI(String sName,long nPos) throws IOException ~czt=
{ DDEn63{
oSavedFile = new RandomAccessFile(sName,"rw"); [iD!!{6+
this.nPos = nPos; jn'8F$GU
oSavedFile.seek(nPos); z&8#1'
} ?.H*!u+9>
j(rFORT
53c6dl
public synchronized int write(byte[] b,int nStart,int nLen) gQ[4{+DSf
{ %WR
int n = -1; %F7k| Na
try{ Yp8$0KK
oSavedFile.write(b,nStart,nLen); IM+PjYJ
n = nLen; R!=XMV3$PH
} >8##~ZuF+
catch(IOException e) v3B ^d}+.
{ ~H.;pJ{ 8
e.printStackTrace (); \a#2Wm
} 8I'?9rt2M
bYz:gbs]4|
!Kis,e
return n; NNT9\JRv_
} C^a~)r.h
nz(OHh!}u
;AaF;zPV
} \n5,!,A
8`D_"3j3g\
[":x
/* 1/ a,7Hl
**SiteInfoBean.java mEGMe@37
*/ .*Z]0~ &|
package NetFox; .IqS}Rh
nsPM`dz/
{_Y\Y&#
public class SiteInfoBean { :2?du
c~V\,lcI
mxIEg?r(
private String sSiteURL; //Site's URL m{g{"=}YR
private String sFilePath; //Saved File's Path yC -4wn*
private String sFileName; //Saved File's Name C-Mop,w
private int nSplitter; //Count of Splited Downloading File 5)vXmAD/0
l"+=z.l6;
bvoR?D\-"
public SiteInfoBean() xn-n{U"
{//nSplitter的缺省值为5 #pZ3xa3R
//default value of nSplitter is 5 8ydOS
this("","","",5); 6l4l74
} p(v.sP4w
QAR<.zXvP
(b(iL\B$D=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MKbW^:
{ \oi=fu=}*
sSiteURL= sURL; *+ 7#z;
sFilePath = sPath; ` p)#!
sFileName = sName; 'F@'4[uda
this.nSplitter = nSpiltter; Mqq7;w@(J
6 R!0v8
uB%`Bx'OW
} # RtrHm
=0Nd\
'b-}KDP
public String getSSiteURL() X0m\
{ EfOJ%Xr[,l
return sSiteURL; $+tkBM
} rIXAn4,dTv
@=$;^}JS|
VL\6U05Z
public void setSSiteURL(String value) |2mEowAd
{ |')Z;
sSiteURL = value; z2r{AQ.&
} kWgxswl7H
[j5L}e!T
Uu G;z5
public String getSFilePath() :wIbKs.r
{ mF "ctxE
return sFilePath; ;&iQNXL
} RsE+\)
/vBpRm
+Ta7b)
public void setSFilePath(String value) 6%)dsTAB
{ !4|7U\;
sFilePath = value; 1:8ZS
} "]sr4Jg=
zgLm~
P5[.2y_qM
public String getSFileName() [z?<'Tj
{ o0AREZ+I
return sFileName; rt f}4.
} 291v R]
<jxTI%'f59
|S/nq_g]
public void setSFileName(String value) =l {>-`:
{ 5{{u #W%=
sFileName = value; %KqXtc`O
} `*WR[c
u{HB5QqK
4-sUy
public int getNSplitter() t; "o,T
{ 'l2`05
return nSplitter; 9Czc$fSSt
} sI#K01;"
cBU>/ zIp
F$d`Umqs;P
public void setNSplitter(int nCount) /']Gnt G.
{ x6m21DWw
nSplitter = nCount; kYx|`-PA<r
} 0nBAO
} zg[ksny
d]CRvzW
J3C"W794}
/* -V(5U!^B
**Utility.java 3HWI;
*/ E:#VS~
package NetFox; 7,Nd[ oL*7
k{uc%6s
V0"UFy?i
public class Utility { JWC{"6
!YCYmxw#
+[:}<^p?cG
public Utility() ZVViu4]?y
{ ^*RmT
q_JES4ofx
Y8(g8RN
} j`(o\Fd )
Nn+leM
//线程睡眠 V*LpO8=
public static void sleep(int nSecond) rT <=`9^{
{ }]kzj0m
try{ {l![{
Thread.sleep(nSecond); H>k=V<
} !DXKn\aQf
catch(Exception e) D}Z].c@E
{ dYW19$W n
e.printStackTrace (); qHklu2_%
} I@e{>}
} 5yuR[VU
njX!Ez
//日志 [26"?};"%
public static void log(String sMsg) YEQ}<\B\&
{ [ q22?kT
System.err.println(sMsg); y1B3F5
} J1hc :I<;
D>PB|rS@
xrS;06$
public static void log(int sMsg) x%5n&B
{ )FYz*:f>&
System.err.println(sMsg); NbSkauF~b
} X^7bOFWE
} zq8LQ4@ay
[*Wq6n
[PdatL2
/* )lE]DG!
**TestMethod.java `#E1FB2M
*/ AKejWh
package NetFox; {O[a+r.n
N.l+9L0b
7&qunK'
public class TestMethod { KYZ/b8C
]W]o6uo7
NN>,dd3T
public TestMethod() twq!@C
{ ///xx/weblogic60b2_win.exe glm29hF
try{ T32C=7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =LC:1zn4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q",n:=PL
SiteFileFetch fileFetch = new SiteFileFetch(bean); lo5,E(7~h
fileFetch.start(); $~75/
} 'D;v>r
catch(Exception e){e.printStackTrace ();} :dc>\kUIv
Vr+X!DeY
@Xts}(L
} P{h;2b{
Mpzt9*7R
BRLrD/8Le
public static void main(String[] args) cQ} ,q+GR~
{ kl,I.2-
new TestMethod(); `qbf_;\
} olB?"M=H
} 5hF iK K7
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