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)); c;!g
} W04av_u 5
for(int i=0;i<nEndPos.length-1;i++) P;foK)AM
{ i&tsYnP2
nEndPos = nStartPos[i+1]; NXoK@Y
} VK .^v<Yo
nEndPos[nEndPos.length-1] = nFileLength; w-FnE}"l
} z4Oo@3$\R
} IlZu~B9c
IvU{Xm"qB
L4974E?S
//启动子线程 UOI^c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [STje8+V
for(int i=0;i<nStartPos.length;i++) L=A\ J^%
{ =3+L#P=i9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l:e9y$_)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \XH@b6{
nStartPos,nEndPos,i); VyZV(k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +t\^(SJ6
fileSplitterFetch.start(); XI}I.M
} mY2:m(9"5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b :\D\X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v4<j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zw=G@4xoU
nEndPos = " + nFileLength); mxtgb$*
// fileSplitterFetch[nPos.length-1].start(); Lt<oi8'N
-{x(`9H;
3ut_Bt\
//等待子线程结束 WM< \e
//int count = 0; G.jQX'%4QG
//是否结束while循环 t[O+B6
boolean breakWhile = false; {g=b]yg\o
,?=KgG1i
z-Hkz
while(!bStop) (&Q)EBdm
{ H1UL.g%d=
write_nPos(); HWtPLlNt
Utility.sleep(500); !LSs9_w
breakWhile = true; Q_lu`F|
?[SVqj2-
./iXyta
for(int i=0;i<nStartPos.length;i++) BR3mAF
{ wixD\t59X
if(!fileSplitterFetch.bDownOver) rgR?wXW]jE
{ #eEvF
breakWhile = false; g~R/3cm4
break; [t}):}~F|
} 2]Fu 1
} GVp
if(breakWhile) hmzair3X
break; q!*MH/R
c,BAa*]K
j;0ih_Z@4W
//count++; i+U51t<
//if(count>4) !$E~\uT
// siteStop(); |0w~P s
} mVrKz
cju@W]!
32KR--mn%
System.err.println("文件下载结束！"); PJwEA
} .HDebi
catch(Exception e){e.printStackTrace ();} a(Sv,@/
} d<Dn9,G
Lw*1 .~
.HOY q
//获得文件长度 BD4"pcr
public long getFileSize() /$*; >4=>f
{ 0~i qG
int nFileLength = -1; TQ~&Y)".
try{ ,lP7 ri
URL url = new URL(siteInfoBean.getSSiteURL()); #Y: ~UVV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ph"iX'J
httpConnection.setRequestProperty("User-Agent","NetFox"); 3:O+GQ*
vK'9{q|g
;_bq9x
int responseCode=httpConnection.getResponseCode(); yTj p-
if(responseCode>=400) C zpsqTQ
{ B%(K0`G#X
processErrorCode(responseCode); }!knU3J
return -2; //-2 represent access is error 0$?qoS
} V%o#AfMI_
{6YxN&
-_w~JCx
String sHeader; <tU :U<ea]
yHtGp%j
A ')(SGSc
for(int i=1;;i++) [BE:+ ID3
{ =_pmy>_z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K9}jR@jy$
//Utility.log(in.readLine()); 2}|vWKej{
sHeader=httpConnection.getHeaderFieldKey(i); B~BUWWMfp
if(sHeader!=null) W=M< c@
{ <EOg,"F
if(sHeader.equals("Content-Length")) M+\rX1T
{ iPNd!_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zo87^y5?G
break; WY3_7k8u
} UzN8G$92qF
} DZF[dxH
else e ^-3etx
break; u`nt\OF
} W3aXW,P.V
} a?l_-Fi
catch(IOException e){e.printStackTrace ();} ;q'DGzh
catch(Exception e){e.printStackTrace ();} y K=S!7p\
C!`>cUhE{
c;nx59w]q
Utility.log(nFileLength); EGr|BLl
i<0D Z_rub
o<~-k,{5P
return nFileLength; m*OLoZVy
} "@aq@mY@
,WzG.3^m
`s#sE.=o
//保存下载信息（文件指针位置） ]9dx3<2_I
private void write_nPos() t4C<#nfo
{ vRq=m8
try{ [`cdlx?Eh
output = new DataOutputStream(new FileOutputStream(tmpFile)); fc["
output.writeInt(nStartPos.length); #R5we3&p
for(int i=0;i<nStartPos.length;i++) ttTI#Fr2
{ `\nON
// output.writeLong(nPos); 6zELe.tq
output.writeLong(fileSplitterFetch.nStartPos); b"`ru~]
output.writeLong(fileSplitterFetch.nEndPos); \=$EmHF
} zK[ 7:<
output.close(); 5/zf x
} Cca~Cq[%*(
catch(IOException e){e.printStackTrace ();} ;*n_N!v
catch(Exception e){e.printStackTrace ();} pE~9o 9
} [BJ$|[11
rDK;6H:u{
$:T<IU[E
//读取保存的下载信息（文件指针位置） *vRNG 3D/
private void read_nPos() XPGL3[w\V
{ 0EcC
try{ t$ACQ*O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tCd{G c
int nCount = input.readInt(); 5@GD} oAn6
nStartPos = new long[nCount]; 3w[<cq.!
nEndPos = new long[nCount]; wpAw/-/
for(int i=0;i<nStartPos.length;i++) LuQ"E4;nY%
{ Xp<A@2wt?
nStartPos = input.readLong(); ~R"]LbeY
nEndPos = input.readLong(); :|*Gnu
} /8 e2dw: \
input.close(); f)p>nW?Z
} Aqx3!
catch(IOException e){e.printStackTrace ();} }wa}hIqx
catch(Exception e){e.printStackTrace ();} fho=<|-
} tjBh$)
-lJx%9>
rTWh(8T
private void processErrorCode(int nErrorCode) YlZYS'_
{ !:]s M-cCt
System.err.println("Error Code : " + nErrorCode); >!:$@!6L
} 0BbiQXU
!$%/ rQ9
vB&F_"/X2
//停止文件下载 >C*?17\
public void siteStop() _"R3N
{ )x_W&*oZ
bStop = true; HPu/. oE
for(int i=0;i<nStartPos.length;i++) krEH`f
fileSplitterFetch.splitterStop(); Jdk3) \
bIvJs9L
uzzWZ9Tv
} yv6Zo0s<J
} mq|A8>g
//负责部分文件的抓取 BK`Q)[
**FileSplitterFetch.java U.zRIhA]
*/ _mIa8K;
package NetFox; Uxj<x`<1x
%J/fg<W1
"z{_hp{T^
import java.io.*; M~d+HE
import java.net.*; a2(D!_dZR
=UI,+P:
T:w2
public class FileSplitterFetch extends Thread { \]L::"![?
;PP_3`
2XETQ;9
String sURL; //File URL Mhu53DT
long nStartPos; //File Snippet Start Position P;HVLflu
long nEndPos; //File Snippet End Position al3BWRq'f
int nThreadID; //Thread's ID \Y>#^b?
boolean bDownOver = false; //Downing is over )V9Mcr*Ce6
boolean bStop = false; //Stop identical l`~a}y"n
FileAccessI fileAccessI = null; //File Access interface Z>>gXh<e[
?9wFV/
!4qps$p{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p[af[!
{ YYZs#_
this.sURL = sURL; rE bx%u7Q
this.nStartPos = nStart; '0])7jq
this.nEndPos = nEnd; q>D4ma^
nThreadID = id; &F<J#cfe8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 " kE:T.,
} BCa90
1{\,5U&
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public void run() ~_f |".T
{ WcZo+r
while(nStartPos < nEndPos && !bStop) *tbpFk4/
{ x 1%J1?Fp
yPzULO4
I9Edw]
try{ _4XoUE\\
URL url = new URL(sURL); `ohF?5J,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); do?S,'(g
httpConnection.setRequestProperty("User-Agent","NetFox"); (:j+[3Ht
String sProperty = "bytes="+nStartPos+"-"; `/gEKrhL-
httpConnection.setRequestProperty("RANGE",sProperty); u$Pf.#
Utility.log(sProperty); f<s'prF
0%qctZy
YP .%CD(K
InputStream input = httpConnection.getInputStream(); VAF:Z
//logResponseHead(httpConnection); \ eyQo>(
:) Fp B"
YQB]t=Ha
byte[] b = new byte[1024]; QJ(e*/
int nRead; YfrTvKX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [X$|dOm'N
{ 1=/MT#d^?
nStartPos += fileAccessI.write(b,0,nRead); 5w,YBUp
//if(nThreadID == 1) vBCZ/F[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [# tT o;q
} pT_e;,KW U
!Wdt:MUI8
*+,Lc1|\
Utility.log("Thread " + nThreadID + " is over!"); tx|"v|&e2
bDownOver = true; 56O<CgJF<
//nPos = fileAccessI.write (b,0,nRead); )z4kP09
} !5' 8a5
catch(Exception e){e.printStackTrace ();} a dz;N;rIY
} gqHH Hh
} &]"_pc/>m
go%X%Os]
nkCRe
//打印回应的头信息 <'4!G"_EP
public void logResponseHead(HttpURLConnection con) LF-+5`
{ +hKPOFa'
for(int i=1;;i++) 3MBz
{ P7BJ?x
String header=con.getHeaderFieldKey(i); ru6HnLhL
if(header!=null) t+4%,n f_1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gS(: c.
Utility.log(header+" : "+con.getHeaderField(header)); 9q0,K" x)
else zOdasEd8!
break; /O(;~1B
} 1vR#FE?
} JG+g88
]5)&36
"|l oSf@
public void splitterStop() ).O2_<&?F
{ wJ]$'c3
bStop = true; %.atWX`b
} D!D%.
i$LV44
UNZVu~WnF
} Jk6/i;4|
dn.c#,Y
u):Rw
/* 1rm$@L
**FileAccess.java omUl2C
*//文件访问(定位，写) -WHwz m
package NetFox; \<MTY:
import java.io.*; BS<>gA R;/
Lw2YP[CR
jtVPv]
public class FileAccessI implements Serializable{ Z]>e& N
uwS'*5tU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FUTyx"
RandomAccessFile oSavedFile; j"$b%|
long nPos; ?[>BssW
PRf\6
A&_i]o
public FileAccessI() throws IOException t;a}p_>
{ ?$8 ,j+&I
this("",0); EpoQV^Ey
} $m%/veD k
AdN=y8T
@ :
public FileAccessI(String sName,long nPos) throws IOException 7_'k`J@_
{ DkMC!Q\
oSavedFile = new RandomAccessFile(sName,"rw"); HIp {< M3
this.nPos = nPos; Rx"VscB6z
oSavedFile.seek(nPos); fS$Yl~-m?
} \?mU$,voI
NNpa69U
G?/8&%8
public synchronized int write(byte[] b,int nStart,int nLen) >,Swk3
{ T.Y4L
int n = -1; Yr(f iI
try{ +WEO]q?K
oSavedFile.write(b,nStart,nLen); c.me1fGn
n = nLen; ah@GSu;7
} U>M>FZ
catch(IOException e) -3XnK5
{ Z_ *ZUN?B
e.printStackTrace (); w7ABnX
} K/LaA4
=VI`CBQ/Um
-){^ Q:u
return n; oIR%{`3"I
} x:wq"X
1XKIK(l
Z.Y8z#[xg
} $HnD|_*
lV*&^Q8.
+wgUs*(W
/* Fe>#}-`
**SiteInfoBean.java Q^5 t]HKn
*/ xx2:5
package NetFox; WRyv >Y
`fE:5y
E^>7jf09,
public class SiteInfoBean { L$07u{Q
Vblf6qaBs
5suSR;8
private String sSiteURL; //Site's URL hdDI%3vk3
private String sFilePath; //Saved File's Path O#Ax P}
private String sFileName; //Saved File's Name ]$k m
private int nSplitter; //Count of Splited Downloading File 3G0\i!*t
[8g\pPQ
C4d1*IQk
public SiteInfoBean() ?=o]Wx0(9
{//nSplitter的缺省值为5 f2K3*}P
//default value of nSplitter is 5 $fpDABf
this("","","",5); 3mn-dKe((
} B'~i Z65
:z5Ibas:
7.'j~hJL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +[nYu)puP
{ ll^O+>1dO
sSiteURL= sURL; e/I{N0SR
sFilePath = sPath; o~N-x*
sFileName = sName; F>{uB!!L4
this.nSplitter = nSpiltter; 6E%k{ r
r,@|Snv)
t#Yh!L6>
} 9CSz<[
:EAfD(D{)
BiAcjN:Z
public String getSSiteURL() ]@ 0V
{ #3jZ7RqzQ
return sSiteURL; HUX+d4sg
} H zK=UcD
[-}%B0S**
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public void setSSiteURL(String value) "[Lp-4A\
{ m/c~2?-;
sSiteURL = value; T>?1+mruM
} u"3cSuqy
<t2?Oii;
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public String getSFilePath() }=R|iz*,!
{ M4]|(A
return sFilePath; 1Ee>pbd
} C8SNSeg
l1j
hIHO a
public void setSFilePath(String value) _$x *CP0(
{ dTNgrW`4
sFilePath = value; 0a;zT O/"v
} 4ov~y1Da)
Qx#)c%v\\
(bXp1*0 ;
public String getSFileName() g9`ytWmM
{ #_5+kBA+>'
return sFileName; !kYmrj**
} X*;p;N
1%{(?uz9
F.w#AV
public void setSFileName(String value) @uWD>(D
{ 8XE0 p7
sFileName = value; 0 N^V&k
} ?Io2lFvI@Y
eS+LFS7*k
=swcmab;
public int getNSplitter() Lf<9GYNy>`
{ $t?e=#G
return nSplitter; e1a%Rj~
} U%olH >1K
[C#pMLp,~
=1uI >[aN
public void setNSplitter(int nCount) Np)!23 "
{ {RO=4ba{J
nSplitter = nCount; &}?e:PEy
} nhxl#
} tt91)^GdYa
^u<+tV
XP1_{\
/* 9tgkAU`
**Utility.java !r,drb
*/ CbQ%[x9|
package NetFox; D~,R@7
<>GyG-q
p5hP}Z4r
public class Utility { 60$
y%AJ>@/;
\FM- FQK
public Utility() 1+#8} z:
{ pu#<qD*w
2HNS|GHb&
&c!-C_L 2
} {,-#;A*yW
>skS`/6
//线程睡眠 wm4e:&
public static void sleep(int nSecond) E{B<}n|}&
{ u?i1n=Ne
try{ Q^OzFfR6
Thread.sleep(nSecond); YG|T;/-
} %(6WrE5F6
catch(Exception e) XUHY.M
{ _Fjv.VQ,
e.printStackTrace (); >aK&T"
} Q.yoxq
} e%\KI\u
>oNs_{
//日志 w5Z3e^g
public static void log(String sMsg) gsH_pG-jU
{ CaMG$X&O
System.err.println(sMsg); VP&lWPA}\$
} }#M|3h;q9+
.BvV[`P
IU}`5+:m
public static void log(int sMsg) :|TBsd|/x
{ )*B.y|b#
System.err.println(sMsg); r+crE %-
} #wfR$Cd
} ;'kH<Iq
5=\b+<pE
R!ij CF\
/* #e[5O|V~
**TestMethod.java ho. a93
*/ :csLZqn[
package NetFox; {s]eXc]K}
gB#t"s)
:KwYuwYS
public class TestMethod { i|e-N?l
^q$sCt}
L\5n!(,0
public TestMethod() t!LvV.g+
{ ///xx/weblogic60b2_win.exe 2vLn#
try{ #kA+Yqy\)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &M0v/!%L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M'sJ5;^5
SiteFileFetch fileFetch = new SiteFileFetch(bean); 191)JWfa
fileFetch.start(); ;pJ7k23(
} f32nO
catch(Exception e){e.printStackTrace ();} ]2+(i
O #"O.GX<
$oz ZFvJF
} 3$TpI5A
\}5\^&}_
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public static void main(String[] args) nBd;d}LD
{ Cb<\
new TestMethod(); F/h)azcn
} Z q)A"'Y
} Bs*s8}6
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