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)); VXlTA>a }
} bSsX)wHm
for(int i=0;i<nEndPos.length-1;i++) ;i?Ao:]
{ ?XO$9J
nEndPos = nStartPos[i+1]; z%5i^P
} "&Ym(P
nEndPos[nEndPos.length-1] = nFileLength; }8J77[>/
} T ) T0.c
} g-j`Ex%
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afOb-G$d=
//启动子线程 v+dt1;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (%]&Pe]
for(int i=0;i<nStartPos.length;i++) QWG?^T fi
{ i~:FlW]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .n1]Yk;,1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !~PLW]Z4
nStartPos,nEndPos,i); 1^rODfY0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .PBma/w W
fileSplitterFetch.start(); pv1J6
} f@lRa>Z(Fm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u!`oKe;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %cJ]Ds%V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @q2If{Tk
nEndPos = " + nFileLength); ]>-#T
// fileSplitterFetch[nPos.length-1].start(); %tiFx:F+
HI6;=~[
Q|Uq.UjY
//等待子线程结束 Q| > \{M
//int count = 0; Wo=Q7~
//是否结束while循环 Rr+Y::E
boolean breakWhile = false; KY$6=/?U_
mwLp~z%OX
Kt3/C'zu
while(!bStop) *L>gZ`Q
{ `~Nd4EA)2
write_nPos(); NMb`d0;(
Utility.sleep(500); A;Rr#q<
breakWhile = true; oW3{&vfz
9NvV{WI-1
4jEPh{q
for(int i=0;i<nStartPos.length;i++) j&)"a,f
{ 6KP"F[8I
if(!fileSplitterFetch.bDownOver) 6-C9[[g<
{ 0]3%BgZ(a8
breakWhile = false; Hp;Dp!PLa
break; JK0L&t<
} {#YGor|
} $>zLa_cn|
if(breakWhile) =BO} hk
break; 13(JW
>i=^Mh-bm
oyV@BHJO@
//count++; xgP/BK2"
//if(count>4) 44axOk!G[/
// siteStop(); TIlBT{A<
} 6( TG/J
<*u[<
&scHyt
System.err.println("文件下载结束！"); Qk?;nF
} #7K&x.w$
catch(Exception e){e.printStackTrace ();} !Tuc#yFw
} gf2<dEff
ZVu&q{s,
.nX+!EXeS
//获得文件长度 * Zb-YA
public long getFileSize() [|<2BQX
{ RGy4p)z*+
int nFileLength = -1; }|>mR];
try{ l?E7'OEF:
URL url = new URL(siteInfoBean.getSSiteURL()); (.Yt| "j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q.:SIBP
httpConnection.setRequestProperty("User-Agent","NetFox"); Yy]^_,r
D/pc)3Ofe
}WXO[ +l
int responseCode=httpConnection.getResponseCode(); g|_-O"l
if(responseCode>=400) Kj;gxYD>6
{ HH/bBM!
processErrorCode(responseCode); A\J|eSG'$
return -2; //-2 represent access is error pcIJija:
} bf]W_I]B
$r})j~c
M;*f(JY$
String sHeader; {2?o:
qv|geBW
7N0V`&}T
for(int i=1;;i++) .} <$2.
{ J5PXmL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); boAu
//Utility.log(in.readLine()); `PK1zSr
sHeader=httpConnection.getHeaderFieldKey(i); T^YdAQeE
if(sHeader!=null) iW\cLp "
{ <}x_F)E[t
if(sHeader.equals("Content-Length")) eglcf z%
{ A+i|zo5p=k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :/'2@M
break; 3n-~+2l
} 9fR`un)f}
} D>wq4u
else )z#
break; qTFktJZw
} 3>%oGbo
} 4kZX$ct}
catch(IOException e){e.printStackTrace ();} Z^w11}
catch(Exception e){e.printStackTrace ();} U6V+jD}L]
``bIqY
9A0wiKp
Utility.log(nFileLength); 'B&gr}@4O=
&`hx
M]PH1 2Ob
return nFileLength; "@IrBi6
} Ng=XH"ce~
D9`J||]E
OL|_@Fv`A
//保存下载信息（文件指针位置） O^(ji8[l
private void write_nPos() E _d^&{j
{ MU2ufKq4)
try{ GZgu1YR
output = new DataOutputStream(new FileOutputStream(tmpFile)); z/zUb``
output.writeInt(nStartPos.length); r}ZL{uWMW
for(int i=0;i<nStartPos.length;i++) O!#yPSq?
{ &wc%mQV
// output.writeLong(nPos); 8z\v|-%Z
output.writeLong(fileSplitterFetch.nStartPos); F&?&8.
output.writeLong(fileSplitterFetch.nEndPos); =8BMCedH|
} ^gx`@^su
output.close(); /7Z5_q_
} }S84^2J_
catch(IOException e){e.printStackTrace ();} 04{*iS95J
catch(Exception e){e.printStackTrace ();} p&'oJy.P
} e@[9WnxYe
&qfnCM0Y
*3 .+19Q
//读取保存的下载信息（文件指针位置） gaeMcL_^a
private void read_nPos() 8!87p?Mz
{ R_iQLBrd
try{ f4F13n_0X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wxw3t@%mNm
int nCount = input.readInt(); hxcRFqX"
nStartPos = new long[nCount]; 9 -7.4!]I
nEndPos = new long[nCount]; ~RdJP'YF-
for(int i=0;i<nStartPos.length;i++) -olD!zKS
{ oCD#Gmr
nStartPos = input.readLong(); &~`Ay4hq
nEndPos = input.readLong(); BK._cDR
} ,CACQhrng
input.close(); r9:Cq
} 2xy &mNx
catch(IOException e){e.printStackTrace ();} ?V6A:8t,
catch(Exception e){e.printStackTrace ();} V'[Lqe,y
} ]z5`!e)L
Lo"w,p`n@
AWkXWl}
private void processErrorCode(int nErrorCode) dN'2;X
{ Jo%5NXts4
System.err.println("Error Code : " + nErrorCode); .~J}80a/
} dUAZDoLi
:oRR1k
8^bc4(H
//停止文件下载 7RW5U'B
public void siteStop() Ww8<f$
{ 05_aL` &eb
bStop = true; =2;2_u?
for(int i=0;i<nStartPos.length;i++) Zx&gr|)}
fileSplitterFetch.splitterStop(); 0K/?8[#
alu3CE
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} >^mNIfdE^=
} !ho~@sc{W
//负责部分文件的抓取 ,+`1/
**FileSplitterFetch.java IK#W80y
*/ "`Y.N$M`k
package NetFox; ~fL:pVp
v2X>%
Nr24Rv
import java.io.*; ""LCyKu
import java.net.*; u~kfz*hz
(sX=#<B%
& w%%{lM
public class FileSplitterFetch extends Thread { RY8Ot2DWi
#Av6BGM|,
QuEfV?)_4
String sURL; //File URL CUz1q*):
long nStartPos; //File Snippet Start Position Snm m(.
long nEndPos; //File Snippet End Position R.KqTEs<k
int nThreadID; //Thread's ID <zmtVE*>g
boolean bDownOver = false; //Downing is over 0#K?SuY.eN
boolean bStop = false; //Stop identical tG1,AkyZ
FileAccessI fileAccessI = null; //File Access interface Grot3a
NI(fJ%U
uK_Q l\d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aI8k:FK"
{ ssdpwn'
this.sURL = sURL; JY$B%R4;]
this.nStartPos = nStart; rU^?Z
this.nEndPos = nEnd; TQ-V61<5
nThreadID = id; 2?=R_&0Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2=?/$A9p
} r3~~4Q4XI>
#9HQW:On
s06tCwPp
public void run() 0}(ZW~&1
{ [=Qv?am
while(nStartPos < nEndPos && !bStop) v4X\LsOP
{ }o>6 y>=
zGm#erE
kzZdYiC
try{ N*d )<8_
URL url = new URL(sURL); m53XN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HH_w!_f
httpConnection.setRequestProperty("User-Agent","NetFox"); %O9kq
String sProperty = "bytes="+nStartPos+"-"; (``EBEn
httpConnection.setRequestProperty("RANGE",sProperty); -N'xQ(#n3q
Utility.log(sProperty); \FVm_)
o;.6Y `-fJ
x6=Yt{
InputStream input = httpConnection.getInputStream(); z5~{WAAI
//logResponseHead(httpConnection); <:v2N/i
[A@K)A$f
3Thb0\<"
byte[] b = new byte[1024]; #w2;n@7;X
int nRead; z:m`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UkO L7M
{ 4Ji6B)B
nStartPos += fileAccessI.write(b,0,nRead); 8H0d4~Wg
//if(nThreadID == 1) e|ChCvk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cP >MsUZWl
} )s @}|`
~g&FeMo
-!X,MDO
Utility.log("Thread " + nThreadID + " is over!"); t:pgw[UJ
bDownOver = true; os=Pr{
//nPos = fileAccessI.write (b,0,nRead); -,;r %7T
} Oa[G #
catch(Exception e){e.printStackTrace ();} U g'y
} wi{qN___
} yrp;G_
6\8 lx|w
s)?=4zJ
//打印回应的头信息 J;?#Zt]`L
public void logResponseHead(HttpURLConnection con) <r[5 S5y
{ [&6VI?
for(int i=1;;i++) *}yOL [
{ :n1^Xw0q
String header=con.getHeaderFieldKey(i); =(!&8U9
if(header!=null) p&Os5zw;|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jzRfD3_s
Utility.log(header+" : "+con.getHeaderField(header)); fgmu*\x<
else Fpz)@0K;
break; NGA8JV/U
} `# N j8
} Qktj
g;N)K3\2
80i-)a\n
public void splitterStop() ]u;Ma G=;
{ x1g0_&F
bStop = true; 9qhX\, h
} 5"x=kp>!d
_$wXHONt
<=]wh|D
} 0nz=whS{
U"Gg ,
HnDz4eD
/* i_ha^mq3
**FileAccess.java p};B*[ki
*//文件访问(定位，写) [| \Z"
package NetFox; -k$*@Hq
import java.io.*; 5>E]C=maD
&rdz({
6P0\t\D0
public class FileAccessI implements Serializable{ z>\vYR$
+<\)b(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X(sN+7DOV
RandomAccessFile oSavedFile; PP2>v|
long nPos; ;oej~
+[ +4h}?
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public FileAccessI() throws IOException `k^d)9
{ Q]Kc<[E
this("",0); TLBIM
} J}$St|1y
av}Giz
In[!g
public FileAccessI(String sName,long nPos) throws IOException C-vFl[@a0
{ vG`;2laY
oSavedFile = new RandomAccessFile(sName,"rw"); /7s^OkQ
this.nPos = nPos; H$M#+EfL
oSavedFile.seek(nPos); <Cbah%X
} B=4xZJPy
MLu@|Xgh
QYm]&;EI
public synchronized int write(byte[] b,int nStart,int nLen) Gr1WBYK
{ **oaR
int n = -1; 7W)*IJ
try{ Ukf4Q\@w
oSavedFile.write(b,nStart,nLen); X?2ub/Nr#Y
n = nLen; E%A] 8y7
} {S+ $C
catch(IOException e) !$q *~F"S
{ cO&(&*J r
e.printStackTrace (); 4,nUCT
} V^v?;f?
f WUFCbSU
z5V~m_RO
return n; RDX$Wy$@L
} E%B:6
;x]CaG)f
K\bA[5+N
} TzPG(f
6~:eO(pK l
nfL-E:n=
/* *OX;ZQg0
**SiteInfoBean.java "@P)
*/ m1d*Lt>F@
package NetFox; Kd<c'!
"[Z'n9C
)<<}8Fs
public class SiteInfoBean { i4Ps#R_wx
&bIE"ZBjt
LqDj4[}
private String sSiteURL; //Site's URL !=-{$& {
private String sFilePath; //Saved File's Path fz9 ,p;b
private String sFileName; //Saved File's Name vtm?x,h
private int nSplitter; //Count of Splited Downloading File GKT^rc-YT-
nm8XHk]
t08E 2sI
public SiteInfoBean() u3[A~V|0=
{//nSplitter的缺省值为5 )BJZ{E*
//default value of nSplitter is 5 X:0-FCT;\
this("","","",5); +!@@55I-
} GLS`1!
M5C%(sQ$
'}F=U(!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j9voeV|7
{ >EVY,
sSiteURL= sURL; EG7.FjnVu
sFilePath = sPath; s<GR ?
sFileName = sName; j\/Rjn+:[
this.nSplitter = nSpiltter; "DpgX8lG_
D^\gU-8M
<w9<G
} ZQ MK1
p+ki1!Ed
.huk>
public String getSSiteURL() @xqjAcfg
{ a7Xa3 vlpO
return sSiteURL; (**k4c,
} oP%'8%tk
eHIsTL@Fp
<kc9KE
public void setSSiteURL(String value) +nOa&d\
{ bb@3%r|_<
sSiteURL = value; [k<w'n*
} JSCZX:5
;7 F'xz"
Klv~#9Si
public String getSFilePath() JX $vz*KF
{ Qf$3!O}G
return sFilePath; 1(nK|
} oh@|*RU
zCuN8
5nQxVwY
public void setSFilePath(String value) u/,ng&!
{ gf]k@-)
sFilePath = value; 2B!Bogs
} 4u.v7r
;d#`wSF`G
79Y;Zgv
public String getSFileName() f,s1k[w/;
{ }zE Qrfl
return sFileName; S0zk<S
} UpoTXAD}k
a6/$}lCq
v"~0 3-SX
public void setSFileName(String value) Y6R+i0guz
{ =Felo8+
sFileName = value; YU(|i}b
} V\=QAN^
HUuZ7jJwf
3<:m;F*#
public int getNSplitter() X1N*}@:/
{ c_RAtM<n
return nSplitter; [ELg:f3}5
} NZaMF.
61*inGRB
PDQ\ND
public void setNSplitter(int nCount) 920 o]Dh=t
{ {i!@C(M3
nSplitter = nCount; %aHQIoxg
} 9NPOdt:@
} -Y:^<C^^&8
VW%eB
&1(PS)s
/* ^j)0&}fB
**Utility.java \ld{Z;e
*/ C3#mmiL-
package NetFox; qe@ctHpn
7G 3*@cl
rO;Vr},3\%
public class Utility { +j">Ju6Q;.
~4t7Q
JIYZ
public Utility() Q9C;_Up
{ X1J'
?yq $ >Qba
YS|Ve*t(L=
} -$0w-M8'
Z'ZN^j{
//线程睡眠 rF>7 >wq
public static void sleep(int nSecond) FsXqF&{
{ N:]Ud(VRM
try{ 3R|C$+Sc
Thread.sleep(nSecond); +. ` I
} )8244;
catch(Exception e) *^WY+DV
{ 017(I:V?(:
e.printStackTrace (); 7Ns1b(kU
} _1sjsGp>
} /#]4lFk:h
x*}*0).
//日志 omEnIfQSO
public static void log(String sMsg) 5kju{2`GF
{ 99]&Xj
System.err.println(sMsg); CKau\N7T
} ,FP<# 0F*a
,vE)/{:d
<T0+-]i
public static void log(int sMsg) !U?Z<zh
{ OY?x'h
System.err.println(sMsg); ]!=,8dY
} D$W09ng-
} }c1?:8p
r:QLO~l/
N7WQ{/PSG
/* nYF;.k
**TestMethod.java )vcyoq
*/ tI-u@ g
package NetFox; re-;s
^vQ,t*Uj=
}1)tALA
public class TestMethod { &!=[.1H<
m0(]%Kdw
}wkZ\q[
public TestMethod() = "N?v-
{ ///xx/weblogic60b2_win.exe 61"w>;d6
try{ #;WKuRv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @UG%B7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Tz"Xm/Gy
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~$FgiW
fileFetch.start(); UOwEA9q%
} E2Jmo5yJR
catch(Exception e){e.printStackTrace ();} S~+er{,ht4
BWHH:cX
"F3M m
} ;I5u"MDHGI
F#S)))#
W? ^ ?Kx
public static void main(String[] args) c@xQ2&i
{ g AZe&"K
new TestMethod(); j4fv-{=$
} Dno'-{-
} `Zm-F
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