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)); =fhRyU:C[z
} }1sd<<\`
for(int i=0;i<nEndPos.length-1;i++) poqNiOm4%
{ ukD:4sv
nEndPos = nStartPos[i+1]; "Vwk&~B%
} %]F{aR
nEndPos[nEndPos.length-1] = nFileLength; jgYe\dinM
} +~lPf.
} H3ob 8+J
Nlm3RxSn
`n e9&+
//启动子线程 0{Zwg0&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~}K$z
for(int i=0;i<nStartPos.length;i++) T(+*y
{ *}ZKQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f+QDjJ?z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U owbk:
nStartPos,nEndPos,i); f kdJgK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DpL|aRdbK
fileSplitterFetch.start(); @CCDe`R*
} N#X(gEV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @Y&(1Wl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gvxOo#8]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \!r,>P
nEndPos = " + nFileLength); <gY.2#6C\%
// fileSplitterFetch[nPos.length-1].start(); }/%^;@q;
"Za'K+4
~NwX,-ri
//等待子线程结束 glNXamo
//int count = 0; mH4Jl1S&
//是否结束while循环 .+`Z:{:BC&
boolean breakWhile = false; {,o =K4CD
FS6ZPjG)
hr GfA
while(!bStop) %4h$/~
{ |-vn,zpe
write_nPos(); SBG.t:
Utility.sleep(500); d@<~u,Mt&F
breakWhile = true; /y5a~3
o~p%ODH
Q-$EBNz
for(int i=0;i<nStartPos.length;i++) qMmhmH)Gp
{ sfEy
if(!fileSplitterFetch.bDownOver) VrZ6m
{ 7@9R^,M4:
breakWhile = false; gn4Sz")
break; @:G#[>nKe
} $N17GqoC
} +Zi@+|"BCN
if(breakWhile) (n~GKcA
break; /Es&~Fn
L[p[m~HjG^
dW2Lvnh!>/
//count++; p?4h2`P
//if(count>4) H83/X,"!w
// siteStop(); <S`N9a
} JnZlz?}^
\y0uGnmCj
-JB~yO?0
System.err.println("文件下载结束！"); '/H+
} Zjkrne{
catch(Exception e){e.printStackTrace ();} #~>ykuq
} zD}2Zh]
i slg5
{qjw S1v
//获得文件长度 94xRKQ}
public long getFileSize() b'5L|1d
{ q8e34Ly7
int nFileLength = -1; n*GsM6Y&
try{ 8X2NEVH]
URL url = new URL(siteInfoBean.getSSiteURL()); M?zwXmTVW0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $ -n?q w
httpConnection.setRequestProperty("User-Agent","NetFox"); d#]XyN>
lQnqPQY
]&RC<imq
int responseCode=httpConnection.getResponseCode(); L]|[AyNu
if(responseCode>=400) kc&MO`2 W\
{ xHY#"
processErrorCode(responseCode); 1 n<7YO7}
return -2; //-2 represent access is error Y)]x1I
} 6P6Pl&
nq"U`z@R
0h",.
String sHeader; 9H4NvB{
7Eett)4
xxC2F:Q?U
for(int i=1;;i++) kw Iw=8q~
{ ?3{:[*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]M#OS$_O@
//Utility.log(in.readLine()); j* \gD
sHeader=httpConnection.getHeaderFieldKey(i); )kiC/Y}k
if(sHeader!=null) [#Y7iN&
{ &>&UqWL
if(sHeader.equals("Content-Length")) D4fHNk)kZ
{ 8KrqJN0\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ekx~svcC&A
break; Pn[R.u(l
} lYt|C^
} F7~T=X)1
else BLskUrPF
break; @z!|HLD+
} :CJ]^v
} [ym ynr3M
catch(IOException e){e.printStackTrace ();} b _#r_`
catch(Exception e){e.printStackTrace ();} !xz0zT.
]NrA2i?
u=u#6%
Utility.log(nFileLength); ^dF?MQA<@
eURj'8o),
:_y}8am;H~
return nFileLength; CVyE5w
} vw/L|b7G
> R5<D'cEN
:6r)HJ5sg
//保存下载信息（文件指针位置） jRCG}'
private void write_nPos() }JePEmj
{ (s2ke
try{ c0%.GcF0{
output = new DataOutputStream(new FileOutputStream(tmpFile)); W%bzA11l
output.writeInt(nStartPos.length); p#eai
for(int i=0;i<nStartPos.length;i++) B5iVT<:a
{ ?i8a)!U
// output.writeLong(nPos); qfQg?Mr
output.writeLong(fileSplitterFetch.nStartPos); 1:+f@#
output.writeLong(fileSplitterFetch.nEndPos); R!8qkG
} KPcOW#.T
output.close(); /)Pf ]
} e0ea2 2
catch(IOException e){e.printStackTrace ();} 7"c^$fj
catch(Exception e){e.printStackTrace ();} hkhk,bhI
} z[q#Dw
O-D${==
YAvOV-L
//读取保存的下载信息（文件指针位置） gLyE,1Z}u
private void read_nPos() 18xT2f
{ lS.&>{
try{ -N3fhW#)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G(~ s(r{%I
int nCount = input.readInt(); L93&.d@m9
nStartPos = new long[nCount]; muc>4!Q
nEndPos = new long[nCount]; Av#_cL
for(int i=0;i<nStartPos.length;i++) )_\ZUem
{ 6ofi8(n[
nStartPos = input.readLong(); tXgsWG?v[H
nEndPos = input.readLong(); 3{wmKo|_X
} XsVp7zk\
input.close(); y)B>g/Hoh
} *)6:yn
catch(IOException e){e.printStackTrace ();} O~1vX9
catch(Exception e){e.printStackTrace ();} eiJ13`T
} )S;pYVVAl
#:yh2y7a%
AP8YY8,
private void processErrorCode(int nErrorCode) <oc"!c;T
{ i^2yq&uT(
System.err.println("Error Code : " + nErrorCode); Gidh7x
} !BocF<UE
nF8|*}w
9mEt**s Ur
//停止文件下载 ^s_BY+#
public void siteStop() ;c!}'2>vM
{ ,1}c% C*,Q
bStop = true; F"k.1.
for(int i=0;i<nStartPos.length;i++) .D~ZE94@
fileSplitterFetch.splitterStop(); U{+<c [
aWe?n;
;E"TOC
} tocZO
} ?'@tx4#v\2
//负责部分文件的抓取 d1"%sI
**FileSplitterFetch.java 3j]P\T
*/ eB$S d
package NetFox; l20fA-T _I
0\N n.x%
TbY<(wrMZ
import java.io.*; ac-R q.GQY
import java.net.*; m,,FNYW
YhVV~bvz*
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public class FileSplitterFetch extends Thread { ]%RX\~Q.4
K|n$-WDG}
^WZcM#~TL
String sURL; //File URL |)7dh B
long nStartPos; //File Snippet Start Position /n9yv
long nEndPos; //File Snippet End Position zj?^,\{A
int nThreadID; //Thread's ID Y_H|Fl^
boolean bDownOver = false; //Downing is over a<W[???m/M
boolean bStop = false; //Stop identical 1h"CjOp,7
FileAccessI fileAccessI = null; //File Access interface u9.x31^
:2qUel\PEC
Zi0B$3iOb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :KJG3j?
{ S-M| 6fv
this.sURL = sURL; |m^qA](M
this.nStartPos = nStart; @bc=O1vX~;
this.nEndPos = nEnd; 8b^v@|)N
nThreadID = id; xS4B"/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A 11w{`EM
} &s +DK`
<rO0t9OH
qB`-[A9HPe
public void run() M=mzl750M
{ &m>yY{be
while(nStartPos < nEndPos && !bStop) TTJFF\$?
{ m_ |:tU(t
(#dwIBBFt
F|eKt/>e
try{ A@-A_=a,
URL url = new URL(sURL); ]/o0p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MQ9Nn|4
httpConnection.setRequestProperty("User-Agent","NetFox"); (Hr_gkGtM
String sProperty = "bytes="+nStartPos+"-"; Mn-f
httpConnection.setRequestProperty("RANGE",sProperty); =`8%qh
Utility.log(sProperty); Z#+{ksU
Auq)
h\jV@g$
InputStream input = httpConnection.getInputStream(); aaN|g{pX
//logResponseHead(httpConnection); HG1)q\Xd
zfAkWSY
)9^0Qk' ]
byte[] b = new byte[1024]; +w(sDH~kd
int nRead; y?ps+ce93
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {HJzhIgCf
{ @_gCGI>Q
nStartPos += fileAccessI.write(b,0,nRead); ~f.fg@v`+v
//if(nThreadID == 1) M@G <I]\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ST#OO!
} "kLu]M<
Ya#,\;dTT
mSw$? >
Utility.log("Thread " + nThreadID + " is over!"); duCso M/
bDownOver = true; :MOr?"
//nPos = fileAccessI.write (b,0,nRead); CXb-{|I}d
} y>:-6)pv
catch(Exception e){e.printStackTrace ();} F"3LG"
} D{Zjo)&tF'
} mfYY?]A*+
S%h[e[[fST
Orb('Z,-3
//打印回应的头信息 "T*Sg
public void logResponseHead(HttpURLConnection con) ^-s'Ad3
{ r%M.rYLG{
for(int i=1;;i++) //SH=>w2
{ ~1x,m.f8
String header=con.getHeaderFieldKey(i); DNARe!pK
if(header!=null) P/BWFN1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j@JhxCe1+R
Utility.log(header+" : "+con.getHeaderField(header)); [fN?=,8
else s Zan.Kc#
break; y"|QY!fK
} .qjVw?E
} J! ;g.q
%J*z!Fe8s
F9hh- "(Z
public void splitterStop() bB|UQaCl
{ !"*!du28jo
bStop = true; <A"T_Rk
} +-~:E_G
R)>/P{A-P
9y BENvq
} A]fN~PR
3Un{Q~6h
P@gVzx)M
/* 4!'1o`8vs
**FileAccess.java %M=[h2SN
*//文件访问(定位，写) ?(9/V7HQ.5
package NetFox; KeU|E<|!
import java.io.*; kz|2PP
V SJGp`
s}MD;V&0
public class FileAccessI implements Serializable{ Vy]y73~
/az}<r8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nz72w_
RandomAccessFile oSavedFile; 2V6=F[T
long nPos; Ekb9=/
.\r=1HZ3
yN9k-IPI
public FileAccessI() throws IOException #fq%903=
{ \8Mn[G9TL
this("",0); "/ N ?$
} %4F Q~
==zt)s.G(+
) >_xHc?
public FileAccessI(String sName,long nPos) throws IOException +D[|Mi
{ S6k R o^2
oSavedFile = new RandomAccessFile(sName,"rw"); G?:{9. (
this.nPos = nPos; gN2$;hb?
oSavedFile.seek(nPos); zf@gAvJ
} L-B"P&
#BB,6E
(mO{W
public synchronized int write(byte[] b,int nStart,int nLen) M^q< qS>d
{ +iS'$2)@
int n = -1; "r!>p\.0O
try{ bW"bkA80
oSavedFile.write(b,nStart,nLen); p`/"e<TP
n = nLen; oXC|q-(C
} #[ei/p
catch(IOException e) Hrjry$t/J
{ 5yOIwzr&Uu
e.printStackTrace (); A -C.Bi;/
} 6Zr_W#SE
&zuPt5G|
e"Y ( 7<
return n; zKh^BwhO|X
} 3,ihVVr&P
TLcev*
#'DrgZ)W
} :G.u{cw
@nC][gNv
b 7XTOB_HO
/* ;jgk53lo
**SiteInfoBean.java _Y{8FN(4
*/ ?*oBevUnCY
package NetFox; 6tx5{Xl-o
4*AkUkP:T
NO)Hi)$X6Y
public class SiteInfoBean { 6o5NeKZ
+9^V9]{Vo
a+HGlj 2>
private String sSiteURL; //Site's URL [Rj_p&'
private String sFilePath; //Saved File's Path ^sF/-/ {?U
private String sFileName; //Saved File's Name -_*ux!
private int nSplitter; //Count of Splited Downloading File 7 KuUV!\h`
Zz,j,w0 Z
:d AC:h
public SiteInfoBean() (DLk+N4UHA
{//nSplitter的缺省值为5 :VkuK@Th`
//default value of nSplitter is 5 >PYLk{q
this("","","",5); VyMFALSe]h
} p*NKM} ]I
!W\za0p
VQ R E]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1"\^@qRv#
{ &@v&5EXOw
sSiteURL= sURL; QZh#&Qf;
sFilePath = sPath; /"J3hSR
sFileName = sName; q`Rc \aWB%
this.nSplitter = nSpiltter; >P9|?:c
gzMp&J
htuYctu`
} 3>T2k }
Qi=pP/Y
h5o6G1ur
public String getSSiteURL() wbpz,
{ ykS-5E`
return sSiteURL; v:IpZ;^
} ` t6|09e
gcA,u)z}R
&cpqn2Z
public void setSSiteURL(String value) 17E,Qnf
{ r}\m%(i
sSiteURL = value; b Y2:g )
} 9Ro7xSeD
s~NJy'Y
=h>jo&=Wad
public String getSFilePath() jtv<{7a
{ ;%Zu[G`C
return sFilePath; Z#t}yC%^d
} o.g)[$M8cF
01<Ti"
a7>^^?|
public void setSFilePath(String value) Vr7L9%/wg
{ Ln$= 8x^T
sFilePath = value; 4n0Iw I
} Krd0Gc~\|
8U)*kmq
+C36OcmT~
public String getSFileName() gSk0#Jt
{ zq'KX/o
return sFileName; %BwvA_T'Q
} AsfmH-4)
s$Vz1B
4*&2D-8<K
public void setSFileName(String value) B'-n ^';
{ C <d]0)
sFileName = value; NtG^t}V
} ++!'6!l
0i>>CvAl}
<xlyk/
public int getNSplitter() }vEMG-sxX
{ S=a>rnF
return nSplitter; C/!7E:
} pG^>y0
]64pb;w"$D
WS.lDMYE7
public void setNSplitter(int nCount) /^9=2~b
{ \gGTkH
nSplitter = nCount; gs(ZJO1 /L
} 6J<R;g23R]
} zwJ\F '
x3l~kZ(
2f5YkmGc";
/* f&I5bPS7}
**Utility.java }BWT21'-Y
*/ F):1@.S
package NetFox; ODxCD%L
7 &iav2q
6f^IAa|
public class Utility { y`Zn{mQ@[
Tq,dlDDOR
TR9dpt+T
public Utility() Eih6?Lpu
{ ;0o% hx
L5wR4Ue)
d^Rea8
} +ZR>ul-c
~?Zm3zOCc2
//线程睡眠 C$d b)5-
public static void sleep(int nSecond) #'97mg
{ ZU;nXqjc
try{ _2WW0
Thread.sleep(nSecond); Ry40:;MYN
} 9h"3u;/,
catch(Exception e) "}2I0tM
{ J;N\q
e.printStackTrace (); _q}^#-
} j9R+;u/!
} mM'uRhO+
IM_SZs
//日志 'u9y\vUy
public static void log(String sMsg) 825 QS`
{ GHQm$|3I
System.err.println(sMsg); MaZVGrcC
} NbK67p:
hX:yn:P~
Nv=&gOy=
public static void log(int sMsg) y>c Yw!
{ |Y30B,=M
System.err.println(sMsg); sC_doh_M
} *9US>mVy
} F.AP)`6+*
2LS91
++BQ==@
/* 7*r!-$
**TestMethod.java XdE|7=+s
*/ ;Q<2Y#
package NetFox; WH<\f|xR
'jYKfq~_cJ
'M fVZho{
public class TestMethod { l - ~PX
S_;m+Ytg
~BgNMO;|
public TestMethod() Fnuheb'&m
{ ///xx/weblogic60b2_win.exe [j?<&^SW
try{ lt%9Zgr[u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A27!I+M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^xq)Q?[{
SiteFileFetch fileFetch = new SiteFileFetch(bean); C|RC9b
fileFetch.start(); cXNR<`
} mcWN.
catch(Exception e){e.printStackTrace ();} Zbf~E {
,Y@4d79
IO"q4(&;P4
} V]/$ dJ
k)agbx
w}U'>fj
public static void main(String[] args) %F(lq*8X
{ 7b(r'b@N
new TestMethod(); j3fq}>=
} ]3 76F7
} 1~S''[
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