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)); N7_(,Gu*R
} @h/-P'Lc=7
for(int i=0;i<nEndPos.length-1;i++) p!\GJ a",
{ B)dG:~
nEndPos = nStartPos[i+1]; BQB<+o'
} _\{/#J;lN
nEndPos[nEndPos.length-1] = nFileLength; 7vc4 JO]
} #oN}DP
} i9T<(sdK+
6NSSuK3
u~~ ~@p
//启动子线程 F6"s&3D{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9~y:K$NO
for(int i=0;i<nStartPos.length;i++) }]^/`n
{ &}\{qFD;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SH O&:2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CY$ 1;/
nStartPos,nEndPos,i); Q% ^_<u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R83PHM
fileSplitterFetch.start(); x{/-&`F
} bH!_0+$P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -z%->OUu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Bm<tCN-4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \S{ihS@J
nEndPos = " + nFileLength); ,bP8"|e
// fileSplitterFetch[nPos.length-1].start(); {XwDvLZ
({D>(xN
tvJl&{-OX
//等待子线程结束 )19#g1rn5
//int count = 0; LLbI}:
//是否结束while循环 D}UgC\u
boolean breakWhile = false; 3sDyB-\&
nGur2}>n
AoK;6je`K^
while(!bStop) P,rLyx
{ dux_v"Xl
write_nPos(); ZP-9KA$"
Utility.sleep(500); ]cWQ9
breakWhile = true; D%6}x^`Qk
(!Xb8rV0_
VFm)!'=I
for(int i=0;i<nStartPos.length;i++) KcW 5
{ qac:"z'9
if(!fileSplitterFetch.bDownOver) r$Ik*R
{ _qh\
breakWhile = false; <N3~X,ch
break; V}Oz! O
} Cu<' b'%;
} ^==Tv+T9U
if(breakWhile) v?n# C
break; J|HV8
+U?73cYN
a.ijc>K
//count++; 6="o&!
//if(count>4) =\\rk,F
// siteStop(); Cv p#=x0
} 9NZq k
z]=Ks_7
?9?o8!
System.err.println("文件下载结束！"); mxe\+j#
} A5[kYD,_
catch(Exception e){e.printStackTrace ();} Yk*_u}?#
} z`D|O|#q
KvI/!hl\
<,H/7Ba
//获得文件长度 YfNN&G4_
public long getFileSize() ]{I>HA5[
{ c)q=il7ef
int nFileLength = -1; Z+4Mo*#
try{ TPY&O{q
URL url = new URL(siteInfoBean.getSSiteURL()); w2^s}NO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^{NN-
httpConnection.setRequestProperty("User-Agent","NetFox"); B =DV!oUg
]eTp?q%0
O.aAa5^uh
int responseCode=httpConnection.getResponseCode(); `[ZA#8Ma
if(responseCode>=400) h-o;vC9fC
{ :JXcs39
processErrorCode(responseCode); TQvjU!>
return -2; //-2 represent access is error !u`f?=s;
} f,BJb+0
#X6=`Xe#
K5(T7S
String sHeader; 7mb5z/N
IEfm>N-]
XD[9wd5w8
for(int i=1;;i++) 5Iv"
{ ]0{,P !
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =E~_F>SD
//Utility.log(in.readLine()); *6v5JH&K
sHeader=httpConnection.getHeaderFieldKey(i); w}29#F\]R
if(sHeader!=null) \`8F.oZ^)
{ {4%ddJn[.)
if(sHeader.equals("Content-Length")) E>"SC\#7
{ "`w*-O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ubsx NCqD
break; = @FT$GQ
} u4[JDB7tH
} XW{cC`&
else #O'g*]j
break; YKx+z[A/p
} \;"S>dg
} aecvz0}@R
catch(IOException e){e.printStackTrace ();} EE qlsH
catch(Exception e){e.printStackTrace ();} 0BOL0<Wq
tV7{j'If
cr^R9dv
Utility.log(nFileLength); "7?xaGh8
zS?DXE
5)w;0{X!P
return nFileLength; @*$"6!3s5
} aCBq}Xcn
0s.4]Zg>5
m# ^).+
//保存下载信息（文件指针位置） ldG$hk'
private void write_nPos() w *o _s
{ t"6u
try{ AP?m,nd6
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?W&ajH_T
output.writeInt(nStartPos.length); \i)@"}
for(int i=0;i<nStartPos.length;i++) <(us(zbk]
{ \/r]Ra
// output.writeLong(nPos); =e6!U5 f
output.writeLong(fileSplitterFetch.nStartPos); A}1:fw\Fn3
output.writeLong(fileSplitterFetch.nEndPos); (. ,{x)H
} [bN_0T.YI
output.close(); <H1e+l{8$
} V("T9g
catch(IOException e){e.printStackTrace ();} N/E=-&E8
catch(Exception e){e.printStackTrace ();} Ge76/T%{Q
} "(:8$Fb
wee5Nirw6
b/=>'2f
//读取保存的下载信息（文件指针位置） ?;go5f+X
private void read_nPos() 0LP>3"Sm
{ r\} O{ZO
try{ /(i~Hpp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M!\6Fl{ b
int nCount = input.readInt(); J!zL)u|
nStartPos = new long[nCount]; o1Wf#Zq
nEndPos = new long[nCount]; G:MQ_tfr&
for(int i=0;i<nStartPos.length;i++) |:d_IB@
{ N&u(9Fxn
nStartPos = input.readLong(); /IC]}0kkp
nEndPos = input.readLong(); <|:$_&(
} `iwGPG!
input.close(); 3d_g@x#9
} )KYU[
catch(IOException e){e.printStackTrace ();} 6x8lnXtA
catch(Exception e){e.printStackTrace ();} qp]sVY
} 4WQ 96|F
Uz7V2r%]
#YLI"/Kn
private void processErrorCode(int nErrorCode) x}N1Wl=8g
{ &)EL%o5
System.err.println("Error Code : " + nErrorCode); a+n?y)u
} OEHw%
kgRgHkAH~
B5va4@
//停止文件下载 cLMFC1=b
public void siteStop() t%Y}JKLR
{ .~4DlT
bStop = true; QST-!`]v
for(int i=0;i<nStartPos.length;i++) SwhArvS
fileSplitterFetch.splitterStop(); e\]CZ5hs3
1ka58_^
et6@);F
} _[J>GfQd
} /6p7k
//负责部分文件的抓取 2>inyn)S
**FileSplitterFetch.java <U""CAE
*/ pKk{Q0Rt
package NetFox; Vj_z"t7q
T'VKZ5W
TK%MVLTK
import java.io.*; 5U(ry6fI=
import java.net.*; A#w*r-P
O,7*dniH
H=_k|#/
public class FileSplitterFetch extends Thread { Bj\oo+L/
/f,*|
qBWt(jY
String sURL; //File URL ;<|m0>X
long nStartPos; //File Snippet Start Position /k^O1+]H
long nEndPos; //File Snippet End Position Y;q['h
int nThreadID; //Thread's ID $C6O<A
boolean bDownOver = false; //Downing is over ]N1gzHaS
boolean bStop = false; //Stop identical |_wbxdq
FileAccessI fileAccessI = null; //File Access interface `"j_]
Iy{&T#e"
(t-JGye>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @!Q\| <
{ n6 AP6PK7
this.sURL = sURL; },tn
this.nStartPos = nStart; LgoUD*MbQ
this.nEndPos = nEnd; y Ide]
nThreadID = id; {@<EVw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jX{t/8v/s4
} .tRWL!
JUC62s#_z
;=?KQq f
public void run() Kyq/o-
{ n4Eqm33
while(nStartPos < nEndPos && !bStop) z8n]6FDiE
{ 4w0Y(y
P/hIJV[
\BxE0GGky
try{ v8o{3wJ
URL url = new URL(sURL); (]p,Z<f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,;-55|o\V
httpConnection.setRequestProperty("User-Agent","NetFox"); ]abox%U=%
String sProperty = "bytes="+nStartPos+"-"; _l!TcH+e
httpConnection.setRequestProperty("RANGE",sProperty); +;wu_CQu
Utility.log(sProperty); <Q?X'.
<YBA 7i
*ZA.O
InputStream input = httpConnection.getInputStream(); bcZ s+FOPd
//logResponseHead(httpConnection); A{b?ZT~2]
Dz>v;%$S-
[1gWc`#
byte[] b = new byte[1024]; S,TK;g
int nRead; .jC-&(R +
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^ G(GjW8
{ H0\5a|X-
nStartPos += fileAccessI.write(b,0,nRead); WD,iY_'7u^
//if(nThreadID == 1) gsp|?)]x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !<xeAo%8
} 6tg0=_c
4zM$I
rZv5>aEI
Utility.log("Thread " + nThreadID + " is over!"); cA{zyq26
bDownOver = true; L|[0&u!
//nPos = fileAccessI.write (b,0,nRead); Gdf*x<T1
} %rZJ#p[e)=
catch(Exception e){e.printStackTrace ();} l~V^
} F2$Z4%x#
} bC@9 */i
' |>
?1u2P$d
//打印回应的头信息 ]MXeWS(
public void logResponseHead(HttpURLConnection con) Z6I^HG{:
{ ~&Gw[Nd1
for(int i=1;;i++) wx|eO[14
{ Fn~?YN
String header=con.getHeaderFieldKey(i); ^s&1,
if(header!=null) 2_]"9d4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XVKR}I
Utility.log(header+" : "+con.getHeaderField(header)); 2nGQD{
else > %U
break; H,H=y},
} wLf=a^c#
} GCTf/V\#
,#PeK(
f._FwD
public void splitterStop() n-7|{1U
{ ,!?&LdPt>
bStop = true; k )T;WCia
} wZA(><\
"`AIU}[_I
UlN+
} R8lBhLs
45;{tS.z,B
CYZx/r<
/* ?=;dNS@i@
**FileAccess.java OJL?[<I
*//文件访问(定位，写) /M;A)z
package NetFox; MR@*09zP(?
import java.io.*; OBCRZ
4M&6q(389
):lq}6J#
public class FileAccessI implements Serializable{ (&U8NeWZ
{Y! -]_5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8N|y
RandomAccessFile oSavedFile; vq~btc.p{&
long nPos; ?6gC;B
N!}r(Dd*
9?M><bBX
public FileAccessI() throws IOException \i-HECc"U
{ (@H'7,
this("",0); 6jiz$x
} jMvWS71
'W/E*O6BY
IZV D.1
public FileAccessI(String sName,long nPos) throws IOException .OHjn|
{ {VPF2JFB[
oSavedFile = new RandomAccessFile(sName,"rw"); Gmi w(T
this.nPos = nPos; JR1/\F<}
oSavedFile.seek(nPos); 85<zl|ZD
} OE(Z)|LF
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3sf+uoV
public synchronized int write(byte[] b,int nStart,int nLen) >900O4
{ $4\,a^
int n = -1; ]C =+
try{ &xlz80%
oSavedFile.write(b,nStart,nLen); *OT6)]|k
n = nLen; YH( 54R
} z (,%<oX
catch(IOException e) VemgG)\
{ fT-yY`
e.printStackTrace (); e5_:15%R\
} G9.+N~GZ.
D_%y&p?<Ls
%.kJ@@_e
return n; g_\U-pzr
} 6_a42#
hVe@:1og#
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} Q]7Rqslz
Br2ZloJ@+
G!J{$0.
/* x;,H>!r"i
**SiteInfoBean.java }\E2Z[
*/ smLXNO
package NetFox; +SGM3tY
T&Y?IE}
t0*JinKI
public class SiteInfoBean { yp=(wcJ
D&f(h][hH?
Zb)j2Xgl
private String sSiteURL; //Site's URL []D@"Bz
private String sFilePath; //Saved File's Path $okGqu8z.O
private String sFileName; //Saved File's Name "=0#pH1o
private int nSplitter; //Count of Splited Downloading File Y4Hi<JWo
n%lY7.z8d
_u$X.5Q;
public SiteInfoBean() io_4d2uBh
{//nSplitter的缺省值为5 _q >>]{5
//default value of nSplitter is 5 /=9t$u|
this("","","",5); 8-Ik .,}
} je6H}eWTC6
zT[[WY4
] 8sVXZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ij_Y+Mnl4:
{ Suixk'-
sSiteURL= sURL; k\UDZ)TQV
sFilePath = sPath; >y%*HC!G
sFileName = sName; S&jZYq**
this.nSplitter = nSpiltter; *xxG@h|5n
9IgozYj
I4kN4*d!N,
} tH0=ysf
(^-i[aJY
lPL>8.j
public String getSSiteURL() FWNO/)~t
{ c!Gnd*!?-
return sSiteURL; <(rf+Ou>I
} -I7"9}j3
-,NiSh}A
1s4+a^&
public void setSSiteURL(String value) u9Wi@sO#
{ :jB8Q$s
sSiteURL = value; iV5x-G`
} H-GlCVq~
XkZ82w#b
@G0k+
public String getSFilePath() RI_:~^nO{r
{ |EuWzhNAO
return sFilePath; Ur`Ri?
} ob=GB71j55
f!;4-.p`
*Z"9QX
public void setSFilePath(String value) W-9^Ncp
{ 0;,4.hsh
sFilePath = value; ZOGH.`
} [m7^Euury
8<}f:9/
|7Z7_YWs
public String getSFileName() (J(JB}[X,
{ f(Q-W6
return sFileName; Sr1xG%;|/
} (;2J}XQvO~
{64od0:T
/an$4?":~
public void setSFileName(String value) 2fp\s5%J}
{ WyH2` xxX
sFileName = value; $Yh7N5XH,
} OHixOI$O
5bZf$$b
#gbJ$1s
public int getNSplitter() `z<k7ig
{ qiQS:0|_
return nSplitter; qSh^|;2?R
} +qsNz*@p"
]r;-Lx{F
ydOJ^Yty
public void setNSplitter(int nCount) j,")c'r&dD
{ y=)Cid
nSplitter = nCount; B`,4M&
} Rckqr7q
} .b*%c?e
a=*&OW
#% PnZ /
/* V=}AFGC85
**Utility.java cx?t C#t
*/ J%c4-'l
package NetFox; '1]Iu@?
JiL%1y9|
Pl4$`Qw#y
public class Utility { OM,-:H,
B>, O@og
Op^r}7
public Utility() $OK}jSH*v)
{ %lsk>V
a=3?hVpB
O(BAw
} x}I'W?g
Jwzkd"D
//线程睡眠 z>$AZ>t%J$
public static void sleep(int nSecond) K@u\^6419
{ Yoy}Zdu}h
try{ _Wn5* Pi%Z
Thread.sleep(nSecond); -gZI^EII
} NMYkEz(&R
catch(Exception e) N0EJHS,>e
{ C.M]~"e
e.printStackTrace (); Y <;A989D
} 8w &A89
} ).HYW _Yih
J0@ ^h
//日志 yZJR7+
public static void log(String sMsg) wmh[yYWc
{ :|i jCg+
System.err.println(sMsg); umV5Y`
} S EdNH.|I
7XLz Ewa
6@_Vg~=S
public static void log(int sMsg) g:bw;6^u
{ ^M60#gJ
System.err.println(sMsg); u\gPx4]4c
} _bp9UJ
} NWCJ|
{J-kcD!bz`
p-QD(+@M
/* O+U9 p
**TestMethod.java r9@4-U7v&
*/ V4Yw"J
package NetFox; HS!O;7s'
<=KtRE>$
GY9CU=-
public class TestMethod { _B4H"2}[Y
;<qv-$P
Zr`pOUk!4
public TestMethod() 8jyg1NN D
{ ///xx/weblogic60b2_win.exe )LESdX
try{ ~x`BV+R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Aa^%_5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i^LLKx7M&
SiteFileFetch fileFetch = new SiteFileFetch(bean); z)$X/v
fileFetch.start(); c=]z%+,b]
} ]AjDe]
catch(Exception e){e.printStackTrace ();} Ar@" K!TS
=1' / ?
>gNVL (
} `4V_I%lJ&
$ K>.|\
y#-mj,e
public static void main(String[] args) OmO/x
{ 9Yg=4>#$
new TestMethod(); $@y<.?k>UP
} RGrra<
} Z/nTI0N{
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