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)); |&3x#1A
} P`$!@T0=
for(int i=0;i<nEndPos.length-1;i++) JhHWu<
{ 7 <9yH:1
nEndPos = nStartPos[i+1]; D}3T|N
} UlcH%pxTt1
nEndPos[nEndPos.length-1] = nFileLength; GsQ*4=C
} HOoPrB m
} (#D*Pl
>j*;vG5T
WIr2{+#
//启动子线程 'G&{GVbXY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r%@Lej5+
for(int i=0;i<nStartPos.length;i++) \f:z+F!6R
{ P 1XK*GZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m<rhIq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NGC,lv
nStartPos,nEndPos,i); '3 33Ctxy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1x)ZB~L
fileSplitterFetch.start(); %" D%:
} gF?[rqz{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N8toxRu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TlZT1H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =(v^5
nEndPos = " + nFileLength); j;b42G~p
// fileSplitterFetch[nPos.length-1].start(); p;T{i._iL
L<^j"!0
= ?D(g
//等待子线程结束 tVuWVJ4M
//int count = 0; _"@CGXu
//是否结束while循环 ;0rGiWC#
boolean breakWhile = false; 'e)^m}:?D
j/`94'Y
k%s_0 @
while(!bStop) <BFQ:
{ M`YWn ;
write_nPos(); ldha|s.*
Utility.sleep(500); Tm}rH]F&
breakWhile = true; XfPFo6
7?j;7.i s(
IU FH:w]
for(int i=0;i<nStartPos.length;i++) N`@NiJ(O;
{ Vd^g9
if(!fileSplitterFetch.bDownOver) E 99hlY~1:
{ $YxBE`)d-
breakWhile = false; M_v?9L
break; j9Ybx#
} ^G&3sF}
} ^d}gpin
if(breakWhile) }KUd7[s
break; GSclK|#tE
}%b;vzkG5
7SDFz}
//count++; &|>S|
//if(count>4) \B F*m"lz
// siteStop(); 1"Z@Q`}
} j/=iMq
CTX9zrY*T
XU!2YO)t;!
System.err.println("文件下载结束！"); -9N@$+T
} S/|,u`g-
catch(Exception e){e.printStackTrace ();} :B3[:MpL}
} j',W 64
k@zy
*eI)Z=8
//获得文件长度 d->|EJP
public long getFileSize() XO#/Fv!
{ rX_@Ihv'
int nFileLength = -1; X%z }VA
try{ +$4(zPs@
URL url = new URL(siteInfoBean.getSSiteURL()); L,y6^J!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z^ }mp@j>
httpConnection.setRequestProperty("User-Agent","NetFox"); infl.
)u))n#P
zp\8_U@
int responseCode=httpConnection.getResponseCode(); Uc/+gz Z;
if(responseCode>=400) #/PAA
{ DPi_O{W>
processErrorCode(responseCode); 5T sUQc
return -2; //-2 represent access is error HeBcT^a
} *6HTV0jv
COH<Tj
J>fQNW!{
String sHeader; mF` B#
UOQEk22
c/c$D;T
for(int i=1;;i++) <: &*
{ a]Lp?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ga?*DI8w
//Utility.log(in.readLine()); d%l{V6
sHeader=httpConnection.getHeaderFieldKey(i); ^u3V E
if(sHeader!=null) OL4z%mDZi
{ oIUy-|
if(sHeader.equals("Content-Length")) U(~+o
{ &-(463
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3u%{dGa
break; z-M3
} 9x,RvWTb
} ]Q[p@gLd
else jzU.Bu.
break; d,Y_GCZ7|W
} Y*mbjyt[?X
} l7&$}x-
catch(IOException e){e.printStackTrace ();} hiNEJ_f
catch(Exception e){e.printStackTrace ();} SG6sw]x
j*~T1i
L^Jk=8
Utility.log(nFileLength); =zwOq(Bh W
~-wPP{!
jxYc2
return nFileLength; (O0Urm
} R|i/lEq
H'Yh2a`!o
i2~
//保存下载信息（文件指针位置） V5}B:SUB
private void write_nPos() s-dLZ.9F
{ 2<M= L1\
try{ Df3rV'/~
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6uKTGc4
output.writeInt(nStartPos.length); &89oO@5
for(int i=0;i<nStartPos.length;i++) 0uBl>A7qhn
{ wEzKqD
// output.writeLong(nPos); `xrmT t X
output.writeLong(fileSplitterFetch.nStartPos); mKYeD%Pm*
output.writeLong(fileSplitterFetch.nEndPos); 3sd"nR?aX
} odIZo|dv
output.close(); 42]pYm(jk3
} ;WldHaZ9r
catch(IOException e){e.printStackTrace ();} ^MBm==heL
catch(Exception e){e.printStackTrace ();} =4h+ M$2
} ~c6}
Ivb4P`{
,t1abp{A
//读取保存的下载信息（文件指针位置） #s!'+|2n
private void read_nPos() TX#m&vh
{ z({hiVs
try{ _{M\Bs2<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .^b;osAU
int nCount = input.readInt(); :O5og[;b
nStartPos = new long[nCount]; ZyEHzM{$
nEndPos = new long[nCount]; %vBhLaE
for(int i=0;i<nStartPos.length;i++) %#$EP7"J
{ .!JVr"8
nStartPos = input.readLong(); t(="h6i
nEndPos = input.readLong(); $+7`Dy!
} 86z]<p (
input.close(); $8a(veXd
} *b];|n{
catch(IOException e){e.printStackTrace ();} iOG[>u0h
catch(Exception e){e.printStackTrace ();} ?&Pg2]g<
} *cyeO*
a ^%"7Ri
@)K%2Y`
private void processErrorCode(int nErrorCode) u[{tb
{ C:G8c[
System.err.println("Error Code : " + nErrorCode); %Q!`NCe+[
} x\QY@9
wY"Q o7
7.j[a*^
//停止文件下载 .;&# )l
public void siteStop() A'nq}t 3
{ Znetzm=0
bStop = true; cW+t#>'r
for(int i=0;i<nStartPos.length;i++) ,K^4fL$C;3
fileSplitterFetch.splitterStop(); Oh4AsOj@
`c'W-O/
Yq/.-4y
} YBnA+l*
} itzyCw2|#
//负责部分文件的抓取 <7Ae-!>x
**FileSplitterFetch.java IJ/sX_k
*/ e${)w-R/e
package NetFox; }W ^: cp
(!:cen~|[
)Z %T27r,^
import java.io.*; JAI)Eqqv]
import java.net.*; aH#l9kCb
bMU(?hb
z~A]9|/61v
public class FileSplitterFetch extends Thread { 7==f\%,
N~F RM& x
Zk[&IBE_
String sURL; //File URL ;>mCalwj
long nStartPos; //File Snippet Start Position 2}W0 F2*
long nEndPos; //File Snippet End Position YZ+RWu9K
int nThreadID; //Thread's ID #0Tq=:AE>
boolean bDownOver = false; //Downing is over Bphof0{<}
boolean bStop = false; //Stop identical cm[c ze+*
FileAccessI fileAccessI = null; //File Access interface Iuh/I +[7
c*R/]Dn
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'FYJMIs
{ *s;|T?~i
this.sURL = sURL; O2"gj"D
this.nStartPos = nStart; vp.ZK[/`
this.nEndPos = nEnd; O-4C+?V
nThreadID = id; r:]1O*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @9&P~mo/
} Y \:0Ev
HEGKX]
Yf[Qtmh]I
public void run() PdVfO8-
{ GHmv} Z
while(nStartPos < nEndPos && !bStop) c,*9K/:
{ ?)\a_Tn
,()0'h}n
y1/o^d+@
try{ r0m*5rd1
URL url = new URL(sURL); _A0w[n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j;Z?WXWDh
httpConnection.setRequestProperty("User-Agent","NetFox"); bz| D-.
String sProperty = "bytes="+nStartPos+"-"; [g2;N,V#
httpConnection.setRequestProperty("RANGE",sProperty); `ImE% r!
Utility.log(sProperty); 'fL"txW
5MSB dO
ce6__f5?
InputStream input = httpConnection.getInputStream(); FW.$5*f='
//logResponseHead(httpConnection); EJ`T$JD
\Y}3cE
i9=&;_z
byte[] b = new byte[1024]; $O^v]>h
int nRead; X*L;.@xA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) & =/
{ C XHy.&Vt
nStartPos += fileAccessI.write(b,0,nRead); *x)8fAr
//if(nThreadID == 1) TW^/sx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lq>&d,F06)
} z.rh]Zq
rL5z]RY
t5lO'Ll*Q]
Utility.log("Thread " + nThreadID + " is over!"); b9XW9O`B
bDownOver = true; !|<=ZF2
//nPos = fileAccessI.write (b,0,nRead); O3CFme
} { m|pl
catch(Exception e){e.printStackTrace ();} 7G)H.L)$m"
} PoIl>c1MS
} 1$*%"5a
b2@VxdFN
NuU9~gSQ
//打印回应的头信息 lHV[Ln`\x
public void logResponseHead(HttpURLConnection con) ?i`l[+G
{ L_w+y
for(int i=1;;i++) 7+hK~
{ c=AOkX3UD
String header=con.getHeaderFieldKey(i); FCkf#
if(header!=null) Y-0?a?q2Fr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g&n)fF
Utility.log(header+" : "+con.getHeaderField(header)); FaBqj1O1
else X<R?uI?L
break; jVH|uX"M5Y
} 0KD]j8^
} . <tq61
P+)DsZ0ig
s#uJ ;G
public void splitterStop() "l >Igm
{ 4Bl{WyMJ|
bStop = true; *Y@nVi
} RyRpl*^
Pm$q]A~
I7&_Xr
} e${>#>
#Mg]GeDJ{
BYKoel
/* M4WiT<|]R
**FileAccess.java mE^o-9/
*//文件访问(定位，写) 4tx|=;@0
package NetFox; 0 P[RyQI
import java.io.*; ?2Kt'1s#
=tU{7i*+
wKH ::!
public class FileAccessI implements Serializable{ fo4.JyBk
4 QZ?}iz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /\)a
RandomAccessFile oSavedFile; Gy[O)PEEh
long nPos; 3/#:~a9Q
cJgBI(S5
,TRTRb;
public FileAccessI() throws IOException $#|gLVOQ
{ <94_@3
this("",0); Jxqh)l
} F]mgmYD%
#oJ5k8Wy
;}z\i
public FileAccessI(String sName,long nPos) throws IOException H'qG/@u-l
{ =YG _z^'
oSavedFile = new RandomAccessFile(sName,"rw"); ` gW<M
this.nPos = nPos; mm5$> [%U
oSavedFile.seek(nPos); vzn{h)D
} ?GTU=gpQ
v2,%K`pAU
QKE9R-KTE
public synchronized int write(byte[] b,int nStart,int nLen) +-B^Z On
{ 6:% L![FX
int n = -1; JH7Ad (:
try{ Ez{MU@Fk
oSavedFile.write(b,nStart,nLen); ql<rU@
n = nLen; b~BIz95
} ?6!]Nl1gr
catch(IOException e) dSCzx .c
{ }oJAB1'k
e.printStackTrace (); A^2L~g[^Q
} bJ_cId8+
V]S1X^
OMk5{-8B
return n; tb?YLxMV
} tDDy]==E
G4 G5PXi
-{ u*qtp
} _hG;.=sr
r ]>\~&?^F
R4Rb73o
/* Qo =Kqv
**SiteInfoBean.java 3gQPKBpc
*/ Vpp;\
package NetFox; ^2]LV6I
^h&I H|
PIXL6
public class SiteInfoBean { {RB-lfrWs
\Ey~3&x9f
Dr;iQkGP
private String sSiteURL; //Site's URL K)Zlc0e
private String sFilePath; //Saved File's Path g+PPW88P;
private String sFileName; //Saved File's Name !jqWwi
private int nSplitter; //Count of Splited Downloading File U1_&gy @y
6x=YQwn~
a,7&"
public SiteInfoBean() 8j1ekv
{//nSplitter的缺省值为5 UhmTr[&
//default value of nSplitter is 5 q8ImrC.'^
this("","","",5); AnZclqtb
} B}d.#G+_$x
&L^CCi
h8jD}9^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I?Q+9Rmm`J
{ fa.0I~
sSiteURL= sURL; F>gmj'-^
sFilePath = sPath; V^Rkt%JY
sFileName = sName; O3V.^_k;
this.nSplitter = nSpiltter; l.nH?kK<
F~U!1)
]TstSF=
} irTv4ZE'+l
0uCT+-
vw<K}z
public String getSSiteURL() YwH./)r=
{ <Q<+4Y{R
return sSiteURL; 3z;_KmM
} 9j*0D("
N~ANjn/wL
+\#Fd
public void setSSiteURL(String value) @tRMe64
{ a <X0e>
sSiteURL = value; u&QKwD Uh
} ngi<v6i
e~v(eK_
N]5m(@h
public String getSFilePath() mCKk*5ws5"
{ H;WY!X$x
return sFilePath; ezTZnutZ
} G[idN3+#
.]Mn^2#j
<@bA?FY
public void setSFilePath(String value) Hoz56y
{ u}6v?!
sFilePath = value; w?csV8ot
} !p 8psi0
em2_pq9q
M,:Bl}
public String getSFileName() 5|$a =UIR
{ > 8]j
return sFileName; rn.\tDeA
} I_ "Z:v{
UBO^EVJ
U/qE4u1J6M
public void setSFileName(String value) ]B9 ^3x[:
{ !F!3Q4
sFileName = value; &S74mV
} ZI ?W5ISdg
6ew "fCrH!
2H?d+6Pt3
public int getNSplitter() _>bRv+RVR
{ TA}UY7v
return nSplitter; EEf ]u7
} R_Dc)
)"O{D`uX
6&2LWaWMo$
public void setNSplitter(int nCount) ;)!"Ty|
{ G5]1s
nSplitter = nCount; 9-jO,l
} :cp
} [~Hg}-c
0o&}mKe
<xS=#
/* lWy=)^)4
**Utility.java s ?l%L!
*/ zREJ#r
package NetFox; Y9}8M27vQG
>R,?hWT
jOtX 60;
public class Utility { DpL8'Dib
:_d3//|
w!q&
public Utility() I6OSC&A`
{ [^PCm Z6n
@Hr+/52B
7S2C/f
} c8'Cq7
zJ& b|L
//线程睡眠 H)JS0 G0
public static void sleep(int nSecond) fB#XhO
{ w;`m- 9<Y
try{ VfSGCe
Thread.sleep(nSecond); 9F_6}.O
} +?N}Y{Y&
catch(Exception e) Ht=$] Px
{ J^H=i)A
e.printStackTrace (); IKf`[_,t]
} |ViU4&d*
} RLKj u;u
~oi_r8K
//日志 C*wdtEGq
public static void log(String sMsg) kN'Thq/ZE
{ A'eAu
System.err.println(sMsg); t;Wotfc[#0
} NoW!xLI
s'2Rs^,hN
S=R3"~p
public static void log(int sMsg) lpEDPvD_Vm
{ kHU"AD}.
System.err.println(sMsg); _Dq Qfc%
} !7` [i
} _p4}<pG
Kd{#r/HZ
r<FQX3
/* 0o68rF5^s
**TestMethod.java cgNt_8qC
*/ ~ v1W
package NetFox; ZC\mxBy
$Qq_qTJu?G
~u/@rqF
public class TestMethod { 41;)-(1
ic~Z_?p
k46gY7y,9
public TestMethod() u:4["ViC
{ ///xx/weblogic60b2_win.exe tyXl}$)y
try{ dF2@q@\.+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^]rxhpS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u_'nOle K
SiteFileFetch fileFetch = new SiteFileFetch(bean); Oc-u=K,B
fileFetch.start(); ze"~Ird
} L[]^{ O
catch(Exception e){e.printStackTrace ();} a@SUi~+3
YmCbxYa7
4_< nQ9K
} 4[l^0
<$C<Ba?;?
(n=Aa;
public static void main(String[] args) ?Y!^I2Y6
{ @W [{2d
new TestMethod(); F^sw0 .b
} h3t$>vs2F"
} j#o3
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