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)); vT7g<
} nbmc[!PwG
for(int i=0;i<nEndPos.length-1;i++) <9ifPSvJ
{ )~ z Z'^
nEndPos = nStartPos[i+1]; L.B~ax.|Z
} ll<mE,
nEndPos[nEndPos.length-1] = nFileLength; |0 !I5|<k
} <o0~H
} )acV-+{
[X/(D9J
Sj-[%D*
//启动子线程 6OB",
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M"U OgS
for(int i=0;i<nStartPos.length;i++) vM4<d>
{ 64U6C*w+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >85zQ 1aL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?QpNjsF
nStartPos,nEndPos,i); ;%zC@a~{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oT&m4I
fileSplitterFetch.start(); gyu6YD8L
} }c|UX ZW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y=2Un).&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JsQ6l%9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kX2d7yQZz
nEndPos = " + nFileLength); l,d,T
// fileSplitterFetch[nPos.length-1].start(); 6RK\}@^=K
"!Lkp2\
:a3xvN-l
//等待子线程结束 [B9;?G
//int count = 0; 'MQ%)hipA
//是否结束while循环 B8V,)rn
boolean breakWhile = false; ]ii+S"U3
u) *Kws
>ttuum12w
while(!bStop) Acu@[I^
{ yn~P{}68
write_nPos(); 1`-r#-MGG
Utility.sleep(500); u^4h&fL
breakWhile = true; mX\ ;oV!
B9M>e'H%<
z~Na-N
for(int i=0;i<nStartPos.length;i++) N:W9},
{ p2d\ZgWD=)
if(!fileSplitterFetch.bDownOver) ZK!A#Jm{
{ T20VX 8gX
breakWhile = false; R^8{bP
break; ^}>/n. %
} [,g~m9
} g1|w?pI1
if(breakWhile) l[%lE
break; (E!!pz
QxpKX_@Q5
YYUe)j{T
//count++; gx;O6S{
//if(count>4) )^/0cQcJ
// siteStop(); PW)aLycPK
} =~|:t&v=c
x-_vl 9P)
cm@;*
System.err.println("文件下载结束！"); %l$W*.j|;
} 91d },Mq:
catch(Exception e){e.printStackTrace ();} p;%<mUI
} :6Pad
CL3xg)x6
kGHC]Fb)
//获得文件长度 C-SLjJw
public long getFileSize() 5 9-!6;T
{ O#_x)13
int nFileLength = -1; :&yDqoQKJ
try{ ^:cRp9l"7
URL url = new URL(siteInfoBean.getSSiteURL()); 2 ZG@!Y|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u#jC#u^M
httpConnection.setRequestProperty("User-Agent","NetFox"); &u8z5pls8
OJ,m1{9$}
h?j_Ry
int responseCode=httpConnection.getResponseCode(); `X -<$x
if(responseCode>=400) I3)Zr+
{ :.&{Z"
processErrorCode(responseCode); L *Y|ey
return -2; //-2 represent access is error U[||~FW'
} $0qMQ%P
=NDOS{($
2`Gv5}LfyR
String sHeader; REA;x-u*
4v.d-^
3 ^}A %-bS
for(int i=1;;i++) fx?$9(r,
{ (bm;*2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )[&zCqDc
//Utility.log(in.readLine()); m5-9yQ=.
sHeader=httpConnection.getHeaderFieldKey(i); ]gP5f@`
if(sHeader!=null) >.DC!QV
{ |wp,f%WK
if(sHeader.equals("Content-Length")) e!X(yJI[O6
{ *g$i5!yM'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :uK btoA
break; -%m3-xZA
} 5PiOH"!19
} ,XB%\[pKe
else C`K^L=8`{
break; jP=Hf=:$
} qd6fU^)i
} JYmAn?o-
catch(IOException e){e.printStackTrace ();} GyC)EFd
catch(Exception e){e.printStackTrace ();} +5X DF
\l,rpVv5m
5%i:4sMx *
Utility.log(nFileLength); 3V;gW%>
t;O1IMF
I/uy>*
return nFileLength; 4Z5#F]OA7
} HEY4$Lf(I
@x{`\AM|%
j43$]'-
//保存下载信息（文件指针位置） q|dH~BK
private void write_nPos() .<&s%{EW
{ ' Q7Y-V
try{ -x]`DQUg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9-lEtl%
output.writeInt(nStartPos.length); K*vU5S
for(int i=0;i<nStartPos.length;i++) $8=@R'
{ p3]Q^KFS
// output.writeLong(nPos); 5<R%H{3j
output.writeLong(fileSplitterFetch.nStartPos); 1W,(\'^R
output.writeLong(fileSplitterFetch.nEndPos); xeA#u J
} :b/J\
output.close(); gv.6h{Ut
} g8pO Lr'
catch(IOException e){e.printStackTrace ();} ;JTt2qQKo
catch(Exception e){e.printStackTrace ();} M$S]}
} wL{qD
B3 zk(RNZ
:1aL ?
//读取保存的下载信息（文件指针位置） r`M6!}oa
private void read_nPos() @WOM#Kc
{ vq'k|_Qi=
try{ =/9^, 6Q(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q]c5MlJXF
int nCount = input.readInt(); k$"d^*R
nStartPos = new long[nCount]; LN^f1/b*
nEndPos = new long[nCount]; P3o@gkXP
for(int i=0;i<nStartPos.length;i++) {"}V&X160o
{ Sycw %k
nStartPos = input.readLong(); m $dV<
nEndPos = input.readLong(); !m y8AWO'
} r o\1]`6
input.close(); /@YCA}|/
} J"CJYuGW,
catch(IOException e){e.printStackTrace ();} 4na8
catch(Exception e){e.printStackTrace ();} x]4Kkpqm
} Gi?_ujZR
!@L=;1,
ocQWQ
private void processErrorCode(int nErrorCode) v#oi0-9o[
{ 3S~(:#|
System.err.println("Error Code : " + nErrorCode); dE(tFZx
} H[WQ=){
z@U}~TvP
M\oVA=d\0
//停止文件下载 ?dq#e9
public void siteStop() ?=On%bh
{ 4<S'
bStop = true; _elX<o4
for(int i=0;i<nStartPos.length;i++) x\\7G^$<h
fileSplitterFetch.splitterStop(); 6 "gj!/e
Akk 3 Qx
:0~QRc-u
} \;9W.d1iU
} u=NG6G
//负责部分文件的抓取 -,#+`>w
**FileSplitterFetch.java -4 Ux,9&
*/ &0 \ ci9o
package NetFox; ~)X[(T{
%w}gzxN^
wSXVyg{
import java.io.*; nb,2,H
import java.net.*; 3MBN:dbQ
|D#2GeBw1h
MQTdk*L_]
public class FileSplitterFetch extends Thread { {7"0,2 Hb?
t#wmAOW
yI;"9G
String sURL; //File URL "VUYh$=[
long nStartPos; //File Snippet Start Position 5LW}h^N
long nEndPos; //File Snippet End Position ! fl4"
int nThreadID; //Thread's ID dF@)M
boolean bDownOver = false; //Downing is over +}kgQ^
boolean bStop = false; //Stop identical k2^a$k}
FileAccessI fileAccessI = null; //File Access interface j;nb?;
;`j/D@H
X@wm1{!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ig#r4nQ=
{ Ol@_(U
this.sURL = sURL; E5GJi
this.nStartPos = nStart; ZCui Fm
this.nEndPos = nEnd; DDd/DAkCX
nThreadID = id; })F*:9i*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6[P-Ny{z
} 6^F'|Wh
kdrod[S
1%~ZRmd e
public void run() Im72Vt:p-
{ ot%.M*h-
while(nStartPos < nEndPos && !bStop) _^S]gmE
{ C"pB"^0
7}o/:
HIc a nk
try{ OM83S|1s
URL url = new URL(sURL); _ -..~K.|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C"V%# K
httpConnection.setRequestProperty("User-Agent","NetFox"); [3>GGX[Ic
String sProperty = "bytes="+nStartPos+"-"; [0;buVU.
httpConnection.setRequestProperty("RANGE",sProperty); /R8p]
Utility.log(sProperty); yt0,^*t_
S;\R!%t_
@tT-JwU
InputStream input = httpConnection.getInputStream(); <^R{U&Z@
//logResponseHead(httpConnection); D{7w!z
Qst$S}n
oF:v JDSS
byte[] b = new byte[1024]; X]j)+DX>
int nRead; A#@_V'a8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ub$n |xn
{ $W8Cf[a
nStartPos += fileAccessI.write(b,0,nRead); YV'pVO'_+
//if(nThreadID == 1) ~2*9{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p3951-D
} FiAY\4
n> w`26MMp
cNK)5- U
Utility.log("Thread " + nThreadID + " is over!"); nhT(P`6
bDownOver = true; ).412I
//nPos = fileAccessI.write (b,0,nRead); )r6EW`$
} oy.[+EI`|
catch(Exception e){e.printStackTrace ();} hUpnI@
} c/3$AUsuO
} ;/O#4]2*
lx0~>K]
B{6<;u)[
//打印回应的头信息 Q(7ob}+jQ
public void logResponseHead(HttpURLConnection con) @E9" Zv-$
{ PO-"M)M
for(int i=1;;i++) ?;ukvD
{ -.I4-6~
String header=con.getHeaderFieldKey(i); h)(*q+a
if(header!=null) !kuX,*}q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /8ynvhF#
Utility.log(header+" : "+con.getHeaderField(header)); QrYa%D+
else W#F Q,+0)
break; w`HI]{hE~N
} P87# CAN
} )q~DTR^z-
C}}/)BYi
k%'m*Tf
public void splitterStop() 3\$wdUFr
{ 2B1xUj ]
bStop = true; yJx?M
} VU.@R,
@J'YV{]
+=$
} 9i$NhfOe
<v 0*]NiX
/#LW"4;*
/* #E7AmmqD%
**FileAccess.java =Ufr^naA
*//文件访问(定位，写) Bn?V9TEoO
package NetFox; zU5Hb2a
import java.io.*; u eb-2[=
TYns~X_PR
8AFczeg[[
public class FileAccessI implements Serializable{ []kN16F
\[:/CxP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m}j:nk
RandomAccessFile oSavedFile; dR^"X3$
long nPos; aG`;OgrH
G5.nPsuM
cW8\d
public FileAccessI() throws IOException F'm(8/A$
{ i{c@S:&@^
this("",0); 95W?{> @
} h11.'Eej`
%b2oiKSBx?
r{?TaiK
public FileAccessI(String sName,long nPos) throws IOException ? zDa=7 J
{ !]` #JAL7
oSavedFile = new RandomAccessFile(sName,"rw"); Qeq5gN]
this.nPos = nPos; x*XH]&V
oSavedFile.seek(nPos); wE\3$ s/{D
} sq/]wzT:
0ZpFE&
CO+/.^s7}S
public synchronized int write(byte[] b,int nStart,int nLen) dP2irC%f8
{ TCKu,}s
int n = -1; @Yw,nQE)b
try{ `\u;K9S6
oSavedFile.write(b,nStart,nLen); Y4.Eq+$gh
n = nLen; GwU?wIIj^
} 9O*_L:4o
catch(IOException e) *LC+ PZV@
{ P$GjF-!:
e.printStackTrace (); TtD@'QXq
} Ey[On^$
F/d7q%I
p>=[-(mt
return n; 0U/,aHvhP
} B@YyQ'
#K\?E.9h
}G<T:(a
} 58xnB!h\}
%(/!ljh_
VZn=rw
/* `6Qdfmk=
**SiteInfoBean.java QnouBrhO
*/ yF._*9Q3hK
package NetFox; Ck =;1sGh
B$Z3+$hfF
P,DC7\
public class SiteInfoBean { T'-FV
RkEN ,xWE
/\s}uSW
private String sSiteURL; //Site's URL SlLw{Yb7\.
private String sFilePath; //Saved File's Path R8ONcG
private String sFileName; //Saved File's Name t`'iU$:1f
private int nSplitter; //Count of Splited Downloading File 4\ c,)U}
owpWz6k7
3-n19[zk
public SiteInfoBean() NSAF4e
{//nSplitter的缺省值为5 1SIq[1
//default value of nSplitter is 5 r,P1^uHx
this("","","",5); LA3<=R]
} )D-c]+yt
_?voU
J T#d(Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N/QiI.V6
{ LK9g0_
sSiteURL= sURL; $4FX(O0Q@
sFilePath = sPath; s?Uh|BfB
sFileName = sName; r`S< A;
this.nSplitter = nSpiltter; &ZHC-qMRK
)}%O>%
wXjFLg!g?
} ^E`(*J/o
|WryBzZ>on
-~" :f8
public String getSSiteURL() nR>r2wMk@
{ jVgFZ,
return sSiteURL; X6+qpp
} VQI(Vp|
=VLS/\A
{Hmo1|_S|
public void setSSiteURL(String value) yqXH:757~
{ \'CN
sSiteURL = value; )py{\r9X
} }V;+l8
3l<S}k@M)
22P$ ~ch
public String getSFilePath() B\*@krI@
{ sAJ7R(p
return sFilePath; U_l'3oPJw
} O#EV5FeF.
lOwS&4UT
\qvaE+
public void setSFilePath(String value) u}bf-;R
{ ow=UtA-^O
sFilePath = value; Si9Z>MR
} @XD+'{]
8.=\GV
\,Lo>G`!
public String getSFileName() 'D1A}X
{ >N\0"F7.
return sFileName; &M/0g]4p
} l=N2lHU
raVA?|'g~
D0(xNhmKz
public void setSFileName(String value) Z|9u]xL
{ '\fY<Q:!
sFileName = value; =$8nUX`
} am_gH
tj]9~eJ-
y %$O-q
public int getNSplitter() Cd79 tu|
{ ;Yfv!\^|
return nSplitter; :4)Qt
} [OTJVpC
b*fgv9Kh'
[+*$\
public void setNSplitter(int nCount) +`M!D }!
{ LWsP ya
nSplitter = nCount; CxhY$%C (L
} d8SE,A&
} Q(d9n8
rKHY?{!
Fhz*&JC#
/* }ZSQ>8a
**Utility.java ffXyc2o
*/ }u+a<:pkK
package NetFox; 6<,dRn
`I$<S(h7
1QZ&Mj^^
public class Utility { _ ~RpGX
{k.MS-q
iz(u=/*\
public Utility() 0yx3OY
{ KD1=Y80P
=ItkFjhBc
z)XRx:YU;$
} b5IA"w
=&0wr6
//线程睡眠 Bx"7%[
public static void sleep(int nSecond) t#nn@Yf
{ ]nQt>R p_
try{ r!P}u
Thread.sleep(nSecond); 2>-S-;i
} o47r<>t
catch(Exception e) RO0>I8c1c
{ 3Y)PU=
e.printStackTrace (); {Y}dv`G#Iu
} aw?=hXR!
} =z{JgD/
+5.t. d
//日志 :0K8h
public static void log(String sMsg) E|YdcS
{ ]Mj/&b>"e
System.err.println(sMsg); Sp}D;7
} biozZ
]J9cVp
GEjd7s]C
public static void log(int sMsg) VKm!Ri$
{ FVv8--
System.err.println(sMsg); 4$/i%B#ad
} .t&R>9cZ^
} Mfk2mIy
T,fI BD:
Tj~IaU
/* 1[*UYcD
**TestMethod.java *'"T$ib
*/ H4OhIxK
package NetFox; G>YAJo
(vR 9H(#
a</D_66
public class TestMethod { ?Y:x[pOe
;)Kh;;e
&`Y!;@K9W#
public TestMethod() xX0-]Y h:
{ ///xx/weblogic60b2_win.exe Cp^@zw*/
try{ d"G+8}.4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7z\m; 1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IdIrI
SiteFileFetch fileFetch = new SiteFileFetch(bean); #jpoHvth
fileFetch.start(); oIGrA-T}
} ~zm7?_"@]
catch(Exception e){e.printStackTrace ();} jUj<~:Q}3o
TGuiNobD
V~GWl1#7
} 1%M&CX
b1pQ`qt
CV$],BM
public static void main(String[] args) D7]#Xk2
{ _$<Gyz*
new TestMethod(); U%7i=Z{^Ks
} 5`~mmAUk;`
} 8$|8`;I(
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