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)); !yj1X Ar
} lHM} E$5
for(int i=0;i<nEndPos.length-1;i++) XdThl
{ j?*n@'
nEndPos = nStartPos[i+1]; RQWUO^&e^
} wN'S+4
nEndPos[nEndPos.length-1] = nFileLength; l=9D!64
} <2@t~9
} 'fK=;mM
Eh;Ia6}
i7T#WfF
//启动子线程 uq9mq"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j%3$ytf|p
for(int i=0;i<nStartPos.length;i++) `f}ZAX
{ OQ2G2>p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fhZwYx&t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XelFGTE
nStartPos,nEndPos,i); SE(<(w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z^gz kXx7
fileSplitterFetch.start(); _:Q^mV=;j
} #]+BIr`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v,ecNuy*d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "?k'S{;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 74 ptd,
nEndPos = " + nFileLength); jN{k }
// fileSplitterFetch[nPos.length-1].start(); &/uakkS
\4$Nx/@Q}
9{nU\am!\
//等待子线程结束 o/ \o-kC}
//int count = 0; J%ws-A?6rN
//是否结束while循环 R-n%3oh
boolean breakWhile = false; |:(BI5&S
n@@tO#!\
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while(!bStop) A|IPQ=
{ |#*+#27
write_nPos(); P >0S ZP
Utility.sleep(500); n$j B"1
breakWhile = true; .wm<l:
nC/T$ #G
ocW`sE?EED
for(int i=0;i<nStartPos.length;i++) -$s1k~o
{ b,HXD~=
if(!fileSplitterFetch.bDownOver) -=rGN"(M _
{ jkuNafp}
breakWhile = false; BI#(L={5
break; {XhpxJ__
} (#je0ES
} q{,yas7}
if(breakWhile) +W>tdxOh
break; $\4Or
mMhe,8E&
&#q%#M:
//count++; QIN# \
//if(count>4) &@7|_60
// siteStop(); I GcR5/3
} d9 8pv%
U_B`SS
Eh_[8:dK
System.err.println("文件下载结束！"); -IV-"-6(
} Q%GLT,f1.
catch(Exception e){e.printStackTrace ();} \BsvUGd
} DUm/0q&
MT&q~jx*
x~yd/ R
//获得文件长度 ER$~kFE2yP
public long getFileSize() x2f_>tu2
{ 8>:2li
int nFileLength = -1; ]}0+7Q
try{ {24Pv#ZG#^
URL url = new URL(siteInfoBean.getSSiteURL()); 1G8t=IA%D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RzSN,bLR
httpConnection.setRequestProperty("User-Agent","NetFox"); \=~<I
}S&SL)
b}q,cm
int responseCode=httpConnection.getResponseCode(); 7 ~ Bo*UM
if(responseCode>=400) .^1=*j(;
{ 2I39fZa
processErrorCode(responseCode); l}c<eEfOy"
return -2; //-2 represent access is error *JOv
} (C QgT3V
}mJ)gK5b 6
`Op ";E88
String sHeader; K<_H`k*x
+V\NMW4d
|s`q+ U-
for(int i=1;;i++) CGg6nCB
{ qx? lCz a"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IX3U\_I#
//Utility.log(in.readLine()); @o^sp|k !
sHeader=httpConnection.getHeaderFieldKey(i); n:!J3pR
if(sHeader!=null) I~T?tm
{ {k]VT4/
if(sHeader.equals("Content-Length")) pcl_$2_
{ 3i$AR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +yea}uUE
break; O@Kr}8^,
} dX3>j{_
} ]V]o%onW
else 2I4P":q
break; Wl2>U(lj
} BZ T%+s;u9
} p.IfJ|
catch(IOException e){e.printStackTrace ();} ";. 3+z
catch(Exception e){e.printStackTrace ();} RGKJO_*J2
4%{m7CK}
V)Xcn'h
Utility.log(nFileLength); \^:f4ZT
3G&1. 8
\d;Ow8%d/
return nFileLength; s`2o\]
} #WG(V%f]
\dMsv1\
A|+{x4s`
//保存下载信息（文件指针位置） $7*Ml)H!9
private void write_nPos() &pAT
{ ;g*6NzdA
try{ ,5*4%*n\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3IxT2@H)
output.writeInt(nStartPos.length); /L 4WWQ5
for(int i=0;i<nStartPos.length;i++) f<'C<xnf
{ 3N21[i2/m
// output.writeLong(nPos); x1et,&,
output.writeLong(fileSplitterFetch.nStartPos); NlMx!f>b%/
output.writeLong(fileSplitterFetch.nEndPos); StVv"YY
} |g{AD`
output.close(); WveFB%@`;
} /_|1,x-Kx
catch(IOException e){e.printStackTrace ();} kShniN
catch(Exception e){e.printStackTrace ();} D.e*IP1R
} zkOgL9 (_8
|+bG~~~%j
hdB[H8Q
//读取保存的下载信息（文件指针位置） pf_ /jR
private void read_nPos() 1d"P) 3dQ
{ `4qKQJw
try{ ~83P09\T%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #rwR)9iC0
int nCount = input.readInt(); GdU W$.
nStartPos = new long[nCount]; loJ0PY'}=
nEndPos = new long[nCount]; -G 'lyH
for(int i=0;i<nStartPos.length;i++) 9vu8koL
{ [1U_c*;i
nStartPos = input.readLong(); G;;~xfE'
nEndPos = input.readLong(); z"#.o^5
} >e;f{
input.close(); Mm!saKT%
} _1'Pb/1
catch(IOException e){e.printStackTrace ();} }t'^Au`X
catch(Exception e){e.printStackTrace ();} 2LU'C,o?
} !Xi>{nV
=.a ]?&Yyh
8.':pY'8"
private void processErrorCode(int nErrorCode) !*gAGt_
{ 3D0I5LF&
System.err.println("Error Code : " + nErrorCode); &?6w2[}
} vNbA/sM
rYQ@"o0/Y
U^&Cvxc[[
//停止文件下载 pt#[.n#f
public void siteStop() ltR^IiA}
{ }q W aE
bStop = true; 8B/9{8
for(int i=0;i<nStartPos.length;i++) Rjl__90
fileSplitterFetch.splitterStop(); z%tu6_4j
-;$/<
p%1m&/`F
} )g_zPt
} [udV }
//负责部分文件的抓取 ,v_r$kh^
**FileSplitterFetch.java gUA}%YXe
*/ u0b-JJ7)BQ
package NetFox; w.p'Dpw
5i#w:O\cz
jqWvLBU!
import java.io.*; D:tZiS=0
import java.net.*; :j<JZs>`R
[uQZD1<q
22~X~=
public class FileSplitterFetch extends Thread { +Uq:sfj,
e622{dfVS
&Ld8Z9IeFp
String sURL; //File URL d/rz0L
long nStartPos; //File Snippet Start Position x)ZH;)
long nEndPos; //File Snippet End Position J6D$ i+
int nThreadID; //Thread's ID D ;$+]2
boolean bDownOver = false; //Downing is over Tk&9Klo
boolean bStop = false; //Stop identical "IJMvTmj
FileAccessI fileAccessI = null; //File Access interface >[4|6k|\x
B RjKV
':)j@O3-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S@NhEc
{ ^)^|;C\`
this.sURL = sURL; _6zP]|VBr
this.nStartPos = nStart; \ZWmef
this.nEndPos = nEnd; q<[ke
nThreadID = id; 9k[},MM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4Xk;Qd
} <D;Q8
0P3|1=
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public void run() B\>}X_\4
{ *Ne2l`!1m
while(nStartPos < nEndPos && !bStop) JD`;,Md
{ `+BaDns
UH&1c8y}
@^6OV)
try{ T^;Jz!e
URL url = new URL(sURL); <&EO=A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A6y~_dt
httpConnection.setRequestProperty("User-Agent","NetFox"); exEld
String sProperty = "bytes="+nStartPos+"-"; q=% C (
httpConnection.setRequestProperty("RANGE",sProperty); B "F`OS[
Utility.log(sProperty); jsi#l
:F w"u4WI
4\SBf\ c
InputStream input = httpConnection.getInputStream(); )F#<)Evw
//logResponseHead(httpConnection); r2F
],}afa!A
2G}7R5``9
byte[] b = new byte[1024]; \R>5F\ 0
int nRead; w$[Ds
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +'Y(V&
{ +9 p`D
nStartPos += fileAccessI.write(b,0,nRead); /xm#:+Sc
//if(nThreadID == 1) ivUsMhx>S,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NRuG?^/}d
} &J/4J
Xt,,AGm}
<AAZ8#^
Utility.log("Thread " + nThreadID + " is over!"); G<^]0`"+)t
bDownOver = true; IL[|CB1v
//nPos = fileAccessI.write (b,0,nRead); p1VahjRE-
} Y^ZBA\D2,k
catch(Exception e){e.printStackTrace ();} ^Im%D(MY
} R4~zL!7;
} h6T/0YhWLP
jle%|8m&@
L^ #<HQ
//打印回应的头信息 F`BgKH!
public void logResponseHead(HttpURLConnection con) sAD P~xvU
{ C=dx4U~
for(int i=1;;i++) A{8K#@!
{ ,JQxs7@2k
String header=con.getHeaderFieldKey(i); ~ S?-{X+
if(header!=null) _+Jf.n20
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v<7Gln
Utility.log(header+" : "+con.getHeaderField(header)); Zu0;/_rN
else rxy{a
break; Yf!*OGF
} wSJ]3gJM`
} l\=-+'Y
=(|xU?OL
4g6ksdFQ
public void splitterStop() 7Js>!KR
{ FfYd+]+?
bStop = true; "Ql}Y1
} uFm+Y]h
gP%|:"
|,1bkJt
} }l}yn@hYC
@Ge>i5q
|YE,) kiF
/* V{T{0b"\U
**FileAccess.java +w k]iH
*//文件访问(定位，写) 62MRI
package NetFox; UBhciZ
import java.io.*; 0~Iu7mPY
%K%^ ]{
%qS]NC
public class FileAccessI implements Serializable{ u(1J=h
V\@jC\-5Vt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ue{vg$5||
RandomAccessFile oSavedFile; ]3O 4\o
long nPos; e~+(7_2
KMK&[E#r
@%EE0)IA
public FileAccessI() throws IOException tjZ\h=
{ $5TepH0D
this("",0); Y8)E]D
} 6o=qJ`m[?
Y{k>*: Ax_
>H0) ph
public FileAccessI(String sName,long nPos) throws IOException F>~ xzc
{ :vc[/<
oSavedFile = new RandomAccessFile(sName,"rw"); XYqpI/s
this.nPos = nPos; ]Q6+e(:~ZH
oSavedFile.seek(nPos); )p$\gwr=2
} QU^/[75Ea0
w=f0*$ue+w
hD nM+4D
public synchronized int write(byte[] b,int nStart,int nLen) eecw]P_?
{ lpl8h4d
int n = -1; J0^{,eY<
try{ "| Kf'/r
oSavedFile.write(b,nStart,nLen); HQq`pG%m6
n = nLen; `IEq@Wr#$!
} <Ctyht0c.
catch(IOException e) <jbj/Q )"
{ Dn~Z SrJ
e.printStackTrace (); #v.L$7O
} Zxg1M
j((hqJr
IE&_!ce
return n; ZhH+D`9
} 8@E8!w&~
B{s]juPG
yh S#&)O
} l iw,O 6
p3g4p
9'1hjd3k
/* 31WZJm^
**SiteInfoBean.java r=h8oUNEJ*
*/ _1sP.0 t
package NetFox; m&Lt6_vi
:`D'jF^S
lp(Nv(S
public class SiteInfoBean { GGH;Z WSe
d-~vR(tU
o6*/o ]]
private String sSiteURL; //Site's URL Q/p(#/y#b
private String sFilePath; //Saved File's Path DL,[k (
private String sFileName; //Saved File's Name M~-h-tG
private int nSplitter; //Count of Splited Downloading File C1 W>/?XC
JfMJF[Mb
*2`:VFEV
public SiteInfoBean() 8$ic~eJ
{//nSplitter的缺省值为5 (#oYyM]
//default value of nSplitter is 5 !Q!&CG5l
this("","","",5); A^-iHm
} 8/Mx5~ R
L/BHexOB
L_^`k4ct
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VUp. j
{ D ZVXz|g
sSiteURL= sURL; mmHJh\2v
sFilePath = sPath; 0 sZwdO
sFileName = sName; Lx%:t YZ
this.nSplitter = nSpiltter; hcyn
G;NB\3~X
RK-x?ZYH'
} gwiR/(1
&3I$8v|!?
QWw"K$l
public String getSSiteURL() vO]J]][
{ _lP4}9p
return sSiteURL; :W~f;k
} 3w6&&R9
7H%_sw5S.
G,]z(%
public void setSSiteURL(String value) 2SciB*5
{ )!eEO [\d
sSiteURL = value; F$h'p4$T
} Ir27ZP
_dr*`yXi
_s*! t
public String getSFilePath() D^u\l
{ 0~]QIdu{AR
return sFilePath; <(YF5Xm6$h
} '00J~j~
j;iL&eo>
oIb) Rq!m
public void setSFilePath(String value) I8k
{ n+?-�
sFilePath = value; ?L\z}0#
} *Tp]h 0
H* /&A9("
]RD5Ex!K?
public String getSFileName() C2G |?=
{ g/#~N~&
return sFileName; ~^$MA$/p
} #ZlM?Q
)b92yP{
t8vc@of$c,
public void setSFileName(String value) Lm|al.Z
{ <tuS,.
sFileName = value; "0-y*1/m
} .S!-e$EJ
[4>r6Hqxr
A"4@L*QV
public int getNSplitter() h<% U["
{ a5?A!k\2
return nSplitter; Dtt-|_EMS
} }9CrFTbx;
g$w6kz_[
~ziexZ=N
public void setNSplitter(int nCount) C[8KlD
{ DA=1KaJ.
nSplitter = nCount; %[Zz0|A
} k[9A,N^lZB
} o&$hYy"<.L
.zSD`v@[
|<(t}}X
/* DYRE1!
**Utility.java ? )_7U
*/ `6F+Rrn
package NetFox; cZi[(K
5v9uHxy
UX_I6_&
public class Utility { x=,8[W#XT
-H\,2FO
>nry0 ;z0,
public Utility() J]fS({(\I
{ GwQn;gkF
+(mL~td01
r1Z<:}ZwK
} [5Y<7DS
YqU/\f+
//线程睡眠 ce'TYkPM
public static void sleep(int nSecond) @^?XaU
{ ~G`J r
try{ 'ere!:GJD
Thread.sleep(nSecond); 7lU.Nit
} *48IF33&s
catch(Exception e) };sMU6e
{ D$nK`r
e.printStackTrace (); g$3>~D
} ]MAT2$"le
} 0{R/<N
n93zD*;5
//日志 2jA%[L9d^
public static void log(String sMsg) h\y-L~2E
{ &1GUi{I
System.err.println(sMsg); U8O(;+
} #J$qa Ul
Hr }k5'
FFe)e>bH
public static void log(int sMsg) &qRJceT(
{ ^\wl2
System.err.println(sMsg); g-@h>$< 1
} s#^pC*,'
} - DL"-%X.
>.LKct*5K
9Nt3Z>d
/* Ze ? g
**TestMethod.java _e'Y3:
*/ 7ZFJexN]
package NetFox; {L0;{
>o[|"oLO
3s(Ia^
public class TestMethod { & _K*kI:
.ECHxDp
k dU! kj
public TestMethod() C6@t
{ ///xx/weblogic60b2_win.exe #Lka+l;L7
try{ 97!5Q~I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TzM=LvA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xmH-!Da
SiteFileFetch fileFetch = new SiteFileFetch(bean); t(?<#KUB-
fileFetch.start(); `ROEV~
} N z~"vi(t
catch(Exception e){e.printStackTrace ();} _CdROo6I
H_B~P%E@]
P5URvEnz:
} |}S1o0v{(a
:vQM>9l7
xncwYOz
public static void main(String[] args) P s#>y&
{ >XE`h9
new TestMethod(); DO^y;y>
} ~_PYNY`"
} r!K|E95oj9
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