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)); e{0O"Jd`
} RueL~$*6.~
for(int i=0;i<nEndPos.length-1;i++) XU$\.g p-
{ [?#-JIZ3T
nEndPos = nStartPos[i+1]; pfg>H
} IeBb#Qedz
nEndPos[nEndPos.length-1] = nFileLength; .T}S[`Yx5
} q|e<b
} |R(rb-v
92L{be;SY
\fL:Ie
//启动子线程 7,3v,N|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IF|%.%I$!U
for(int i=0;i<nStartPos.length;i++) <nn!9V\C
{ 9|//_4]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e6^iakSd.L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uB35CRd
nStartPos,nEndPos,i); i%9xt1c_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /f -\ 3
fileSplitterFetch.start(); BU;E6s>P
} ) 2Hl\"F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +K[H!fD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j(\jYH>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~kPZh1n`
nEndPos = " + nFileLength); $-f(.S
// fileSplitterFetch[nPos.length-1].start(); j~Ubpf
3/2G~$C
r$-]NYPi
//等待子线程结束 6-uB[$ko
//int count = 0; F% K}&3
//是否结束while循环 gnU##Km|
boolean breakWhile = false; sxQMfbN
S31+ j:"
G-sA)WOF
while(!bStop) 84maX'
{ k'+Mc%pg4E
write_nPos(); PiwI.c
Utility.sleep(500); !:Clzlg
breakWhile = true; Q GDfX_
kM/;R)3t4/
h-[FUPfuw
for(int i=0;i<nStartPos.length;i++) Mhze!!
{ b `.h+=3
if(!fileSplitterFetch.bDownOver) Hsz).u
{ '} LAZQ"
breakWhile = false; )wz3m L
break; )F4P-u
} 6B>H75S+H
} QsH Fk5)
if(breakWhile) JD$;6Jv3P
break; ziui
QOY M/1U
`?:X-dh_
//count++; w97B)Kn6
//if(count>4) 7 {#^zr
// siteStop(); d/`Q,Vl
} NI?YUhg>
uSK<{UT~3
$WK~|+"{>
System.err.println("文件下载结束！"); ~gvw6e*[
} {F+iL&e)
catch(Exception e){e.printStackTrace ();} :HG5{zP
} rui]_Fn]I
>vY5%%}
j /=4f�
//获得文件长度 .[4Dvt|>6
public long getFileSize() >D/+04w
{ B>W!RyH8o
int nFileLength = -1; 2s:$4]K D
try{ `.a~G y
URL url = new URL(siteInfoBean.getSSiteURL()); H:M;H=0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xu7Q^F#u
httpConnection.setRequestProperty("User-Agent","NetFox"); Acib<Mi2!-
5 MD=o7O^
p-o!K\o-1
int responseCode=httpConnection.getResponseCode(); x(/{]$h
if(responseCode>=400) iSxuor^;
{ VVyms7 VN
processErrorCode(responseCode); p8Wik<'^
return -2; //-2 represent access is error MUd 9R
} _-/<bO
AjA.="3
#q%V|Ajq
String sHeader; ",qJG]_ <
9n[ovX 7n!
B7!dp`rPp
for(int i=1;;i++) w>ap8><4
{ !*l5%H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2k$~Mv@L
//Utility.log(in.readLine()); Qcf5*]V
sHeader=httpConnection.getHeaderFieldKey(i); )j>BvO
if(sHeader!=null) 11>K\"K}
{ CA{(x(W\:
if(sHeader.equals("Content-Length")) COf>H0^%Q
{ nJ-U*yz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x#_0 6
break; [Vaw$c-+[y
} coQ>CbHg
} bR}{xHe
else Iib39?D W
break; xK3}zN$T
} 2{E"#}/
} z(&~O;;N#
catch(IOException e){e.printStackTrace ();} fer~NlX
catch(Exception e){e.printStackTrace ();} +Tw]u`
\6U$kMGde
$pg1Av7l
Utility.log(nFileLength); yl[6b1
sjj*7i*
e2PM^1{_
return nFileLength; `vPc&.-K
} u9}k^W)E
'P^6H$0
<>FpvdB
//保存下载信息（文件指针位置） ;,yjkD[mWE
private void write_nPos() _ X* A
{ x#{.mN
try{ R2[-Q"|Ra
output = new DataOutputStream(new FileOutputStream(tmpFile)); u\zP`Y
output.writeInt(nStartPos.length); .j)f'<;%
for(int i=0;i<nStartPos.length;i++) b:w {7
{ ZNEWUt{+;^
// output.writeLong(nPos); ~Z#jIG<?g
output.writeLong(fileSplitterFetch.nStartPos); g/ict2!
output.writeLong(fileSplitterFetch.nEndPos); PHh&@:
} 5#v|t\ {
output.close(); C`0;
} xi =\]
catch(IOException e){e.printStackTrace ();} ^ |^Q(
catch(Exception e){e.printStackTrace ();} LiF(#OuZ
} ]wQ#8}zO
BL^8gtdn
Uj[E_4h
//读取保存的下载信息（文件指针位置） |Vs?yW
private void read_nPos() <8Zm}-U
{ i!JVGs
try{ \tWFz(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |#. J
int nCount = input.readInt(); j%qBNoT~
nStartPos = new long[nCount]; +w]KK6
nEndPos = new long[nCount]; 9 ZD4Gv
for(int i=0;i<nStartPos.length;i++) J!GWP:b3
{ 1/H9(2{L
nStartPos = input.readLong(); XPt<k&o1,
nEndPos = input.readLong(); yfd$T}WW6
} QIMoe'p
input.close(); &~xzp^&
} 2-<i#nA3
catch(IOException e){e.printStackTrace ();} ^<}eONa
catch(Exception e){e.printStackTrace ();} /M1 /
} NJ;D Qv
LPNJuz
_K?{DnTb
private void processErrorCode(int nErrorCode) 2/c^3[ccR
{ rIE m
System.err.println("Error Code : " + nErrorCode); 2yyJ19Iul
} ^U`Bj*"2
[;F%6MPK^
-W:te7
//停止文件下载 n!B*n(;!u
public void siteStop() h!L/ZeRaV
{ AMhHq/Dw
bStop = true; m*d {pX
for(int i=0;i<nStartPos.length;i++) Yc,qXK-
fileSplitterFetch.splitterStop(); }op0`-Xb
}? W[D
tC,R^${#
} 5Cp6$V|/kv
} $dp;$X3
//负责部分文件的抓取 x@ZxV*T^
**FileSplitterFetch.java kyFq
*/ (0=e ,1 n
package NetFox; v?U;o&L(
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i'$V'x'k
import java.io.*; VR@V3 ~
import java.net.*; {F/0pvP9
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Sl8A=Ez
public class FileSplitterFetch extends Thread { P)2.Gx/
NRM=0-16u$
VoOh$&"M
String sURL; //File URL a&Stdh
long nStartPos; //File Snippet Start Position KL8G2"Z
long nEndPos; //File Snippet End Position 2k}" 52
int nThreadID; //Thread's ID Wy[Ua#Dd
boolean bDownOver = false; //Downing is over )e$}sw{t
boolean bStop = false; //Stop identical |(Bc0sgw}
FileAccessI fileAccessI = null; //File Access interface 7ktSj}7W]
JYt)4mOo
Vg6/1I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tf VK
{ INd:_cT4l
this.sURL = sURL; i58&o@.H<u
this.nStartPos = nStart; Gd:TM]rJ
this.nEndPos = nEnd; I,*zZNvRi
nThreadID = id; atW=xn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UkE fuH
} !&$uq|-
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,[ UqUEO
public void run() w&vZ$n-|
{ mM> L0
while(nStartPos < nEndPos && !bStop) ]5V=kNui
{ dOm@cs
+ld]P}
Pp*:rA"N
try{ < )dqv0=
URL url = new URL(sURL); J-6l<%962%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3N(5V;ti
httpConnection.setRequestProperty("User-Agent","NetFox"); X7cqAi
String sProperty = "bytes="+nStartPos+"-"; <}G*/ z?/
httpConnection.setRequestProperty("RANGE",sProperty); 0%Y8M` ~s7
Utility.log(sProperty); fd{75J5%
=i4%KF9x
ig Q,ZY1
InputStream input = httpConnection.getInputStream(); >tmv3_<=
//logResponseHead(httpConnection); A)2eo<ij4
3tO=
_M;n.?H
byte[] b = new byte[1024]; ;.O#|Z[
int nRead; CNo'qlvF5N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qT<OiIMj^
{ B<99-7x3
nStartPos += fileAccessI.write(b,0,nRead); S2TyNZbQ
//if(nThreadID == 1) x6i7x"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M+7&kt0;
} 7Rba@ cs9
Xjy5Yj
U?bQBHIC
Utility.log("Thread " + nThreadID + " is over!"); *{t]fds
bDownOver = true; Ix-bJE6+I,
//nPos = fileAccessI.write (b,0,nRead); >FVBn;1
} {Dc{e5K
catch(Exception e){e.printStackTrace ();} N(6Q`zs
} >1}RiOd3
} 4"om;+\
I%^Bl:M
K1th>!JW'
//打印回应的头信息 6n|R<DO%\
public void logResponseHead(HttpURLConnection con) p;y\%i_
{ Y#VtZTcT
for(int i=1;;i++) CAbeb+O
{ 9J*M~gKbz
String header=con.getHeaderFieldKey(i); X j>?P/=Z
if(header!=null) ! sN~w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yDuMn<=3
Utility.log(header+" : "+con.getHeaderField(header)); XF6ed
else 'n>v}__&|
break; LU-,B?1
} c:J;Q){Xz
} ii3{HJ*C
\ah.@s
A~@u#]]<n
public void splitterStop() (~6D`g`B
{ W~!uSrY
bStop = true; lYF~CNvE
} m@Q%)sc)
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ezq<)gJc
} /8Sr(
q':P9o*N?
=tKb7:KU
/* (GeOD V?U
**FileAccess.java hxB` hu-
*//文件访问(定位，写) `kRv+Qwfa
package NetFox; e5s=@-[
import java.io.*; ^Fn~@'
B24,;2J
mRECdGst
public class FileAccessI implements Serializable{ N!{waPbPi
,\DSi&T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !,(6uO%
RandomAccessFile oSavedFile; 8mmHefZ}2!
long nPos; yUyx&Y/
WZ A8D0[
[X\<C '<
public FileAccessI() throws IOException \#hp,XV>
{ [ r<0[
this("",0); C$<['D?8
} 1.U9EuI
1v?|n8
@ptE&m
public FileAccessI(String sName,long nPos) throws IOException S^,q{x*T
{ &gr)U3w
oSavedFile = new RandomAccessFile(sName,"rw"); xoYaL
this.nPos = nPos; Ec/-f`8
oSavedFile.seek(nPos); mu>L9Z~(L_
} i?+>,r@\p
A*a:#'"*N
>!gW]{
public synchronized int write(byte[] b,int nStart,int nLen) wn&5Ul9Elb
{ UNC%<=
int n = -1; ju8DmC5
try{ Qp5YS
oSavedFile.write(b,nStart,nLen); j1sgvh]D
n = nLen; $Lc-}m9n
} }jI=*
catch(IOException e) rIhe}1
{ H6vO}pq)r
e.printStackTrace (); 6+iZJgwAy
} gz~)v\5D/
%8]~+#]p
EQvZ(-_;4
return n; !D!1%@ e
} ,WKWin
9EU0R H
s6YnNJ,SK
} {Rv0@)P$
XZew$Om[
*;0Ods+IcY
/* ,QZNH?Cp/
**SiteInfoBean.java xV+cX*4h
*/ qQ/<\6Sl
package NetFox; <`P7^ 'z!
1oSU>I_i
VS\+"TPuH
public class SiteInfoBean { l.Yq4qW
C"[d bh!
]T<\d-!CZN
private String sSiteURL; //Site's URL t91z<Y|
private String sFilePath; //Saved File's Path tDQo1,(oY
private String sFileName; //Saved File's Name "~nUwW|=1
private int nSplitter; //Count of Splited Downloading File d"#& VlKcv
$;Nw_S@
7W7yjG3g
public SiteInfoBean() z<~yns`Y.
{//nSplitter的缺省值为5 J^xIfV~zt
//default value of nSplitter is 5 f.{/PL
this("","","",5); &~MM\,KML
} -SeHz.`N
j}F;Bfq!
'0tNo.8K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }P(<]UF
{ 0/~20KD{s
sSiteURL= sURL; a*3h|b<
sFilePath = sPath; bH1MDBb2
sFileName = sName; &f_ua)cyY
this.nSplitter = nSpiltter; }u&,;]
/8Xd2-
<3WaFi u
} rT/4w#_3
'6zk>rN
9'I$8Su
public String getSSiteURL() RkTO5XO
{ \*i[m&3;q
return sSiteURL; ZhnRsn9
} FrL ;1zt
F*{1, gb
mO0a: i!
public void setSSiteURL(String value) %;-r->
{ L`@)*x)~R
sSiteURL = value; !IAd.<,
} yGZsPQIaV
/~6)Vt
Q?WgGE4>
public String getSFilePath() ELa:yIl0
{ JM>4m)h#
return sFilePath; 7a5G,C#QQ
} UkzLUok]U
9zac[tno
J=7<dEm&
public void setSFilePath(String value) \ x>#bql+
{ 227 Z6#CF!
sFilePath = value; 3Jj 3!aDB
} G}NT[
bQBYzvd
yh{Wuz=T
public String getSFileName() VcpN PU6
{ LP:U6 Z
return sFileName; <v+M~"%V
} OtD!@GQ6
F0 ^kUyF|
cjyb:gAO
public void setSFileName(String value) 1 ,e`,
{ p5?8E$VHV
sFileName = value; /}&@1
} oV,lEXz
fF.qQTy;7
oaMh5FPy
public int getNSplitter() kXY p.IVA
{ ;UoXj+Z
return nSplitter; F?.J1]
} OJTEvb6nPg
q%\rj?U_
jdW#; ]7+y
public void setNSplitter(int nCount) yr,Oq~e
{ wW1>#F
nSplitter = nCount; !dZpV~g0
} a/s6|ri`0
} ; +%|!~
O$$$1VHYo
yE>f.|(
/* $,DX^I%!
**Utility.java 0{zA6Xu
*/ ,W:Bh$%
package NetFox; K.I\E
hJasnY7
` 8OA:4).
public class Utility { t}A n:
F%F:Gr/
w?Nx^)xX
public Utility() q@8j[15
{ 0$e]?]X6
y+K21(z.
EWn\]f|
} <h<4R Rj
B%^ $fJ|
//线程睡眠 N%" /mcO
public static void sleep(int nSecond) Mg^.~8\de
{ .BqSE
try{ &Dw8GU}1
Thread.sleep(nSecond); ~ @Au<
} hY^-kdQ>M
catch(Exception e) {nyVC%@Y
{ elw}(l<F
e.printStackTrace (); E])X$:P?
} WTZr{)e
} }2i3
N,Ys}qP
//日志 "H!2{l{
public static void log(String sMsg) L.1pO2zPe
{ Bp:i[9w
System.err.println(sMsg); a eo/4
} PN@[k:5(
I~: AWS9
0"O22<K3a
public static void log(int sMsg) A"`(^#a
{ .f~x*@
System.err.println(sMsg); q9mYhT/Im
} p/GYfa dU
} AroXf#.
xs ^$fn\
]&kzIxh
/* _m8JU
**TestMethod.java *q/oS8vavd
*/ 5Zdxn>
package NetFox; )/1,Ogb%_
Z-BPC|e
;q6FdS
public class TestMethod { B\z4o\am%
SOPQg?'n=V
%`Q<_LTU
public TestMethod() -A A='s
{ ///xx/weblogic60b2_win.exe Axtf,x+lH
try{ ,0=@cJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m+Bt9|d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QA3q9,C"
SiteFileFetch fileFetch = new SiteFileFetch(bean); h r!Htew4
fileFetch.start(); _'lrI23I
} Tfba3+V
catch(Exception e){e.printStackTrace ();} s]p3dB#
B{0m0-l
RO1xcCp
} 9G'Q3? z
ua-cX3E
(8*& 42W
public static void main(String[] args) Y"U -Rc
{ i C nWb
new TestMethod(); k_c8\::p#
} h) .([
} oU.LYz_
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