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)); &xMJ^Nv
} ~_^o?NE,
for(int i=0;i<nEndPos.length-1;i++) GwIfGixqH
{ J,77pf!B
nEndPos = nStartPos[i+1]; +Hm+#o
} ;Kd{h
nEndPos[nEndPos.length-1] = nFileLength; (w@MlMk
} &j~|3
} wDC/w[4:
)su <Ji*
{ ves@p>?
//启动子线程 O|7{%5h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >[P7Zlwv4
for(int i=0;i<nStartPos.length;i++) 1p"EE~v
{ 9'*ZEl^?D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BC0c c[x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '|A5a+[
nStartPos,nEndPos,i); +qW w-8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1b]PCNz
fileSplitterFetch.start(); bCx1g/
} %F]9^C+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ))+98iU1s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oTV8rG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }.|5S+J?[
nEndPos = " + nFileLength); r/$)c_x`
// fileSplitterFetch[nPos.length-1].start(); i,b7Ft:F&
i11GW
_Ag/gu2-?
//等待子线程结束 cZX&itVc:
//int count = 0; AL$Ty
//是否结束while循环 @7Rt[2"e
boolean breakWhile = false; <B{VL8IA>
@p` CAB
V1b_z
while(!bStop) }ok nB
{ /$.vHt5nt
write_nPos(); \t(r@qq
Utility.sleep(500); }GNH)-AG)$
breakWhile = true; sluZ-,zE
xS-nO_t 'E
uV$d7(N}"
for(int i=0;i<nStartPos.length;i++) wj5s5dH
{ I%b:Z
if(!fileSplitterFetch.bDownOver) .q[sk
{ V7'x? pt
breakWhile = false; |iJZC
break; ~U*N'>'=)
} GvtI-\h]
} it|:P
if(breakWhile) 1YD.jU^;HD
break; l'lDzB+.*
&OR*r7*Z
)n[Mh!mn
//count++; ?,e:c XhE2
//if(count>4) @`*YZq>p
// siteStop(); 7MJ)p$&
} <21^{ yt1
kc']g:*]Y
M~Dc5\T
System.err.println("文件下载结束！"); 5*za]
} 1xV1#'@[Jd
catch(Exception e){e.printStackTrace ();} <=2*UD |
} uqeWdj*Y
XlJux_LD:
"EkO>M/fr
//获得文件长度 ^X'7>{7Io
public long getFileSize() ~e~Mx=FT0
{ I[IQFka}
int nFileLength = -1; +~.Jw#HqS
try{ dY`J,s
URL url = new URL(siteInfoBean.getSSiteURL()); $ rnr;V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \iSBLU
httpConnection.setRequestProperty("User-Agent","NetFox"); >mSl~.I2
%= ;K>D
'=Y~Ir+
int responseCode=httpConnection.getResponseCode(); #X_M
if(responseCode>=400) $^ dk>Hj>4
{ buyz>ICP
processErrorCode(responseCode); \eN/fTPm
return -2; //-2 represent access is error *n?:)(
} b>._ r&.
_u5U> w
_JO @O^Ndd
String sHeader; ${eh52)`
/UyE- "S
,.F+x}
for(int i=1;;i++) *heQ@ww
{ (W/UR9x)|d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~ZN9 E-uL
//Utility.log(in.readLine()); u#|Jl|aT
sHeader=httpConnection.getHeaderFieldKey(i); F4gc_>{|
if(sHeader!=null) "g[UX{L
{ *j:5
if(sHeader.equals("Content-Length")) _J;a[Ky+[
{ M)Q+_c2*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }CqIKoX.
break; pz=Wq4l
} nEr, jd~f
} Nuq/_x
else V#KM~3e
break; _%!hkc(
} j'n= Xh
} QV1%Zou
catch(IOException e){e.printStackTrace ();} @S):a`J
catch(Exception e){e.printStackTrace ();} U%l{>*q
Pw.+DA
n_glYSV!
Utility.log(nFileLength); mJT m/C
0[Aa2H*
Y [S^&pF
return nFileLength; }qPo%T
} {eV_+@dT
|JQ05nb
[*v\X %+
//保存下载信息（文件指针位置） H\vO0 <X
private void write_nPos() $i Tgv?.Q
{ ktRdf6:~
try{ 0}N^l=jQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); >sq9c/}X
output.writeInt(nStartPos.length); zFIKB9NUn
for(int i=0;i<nStartPos.length;i++) 8Qh/=Ir
{ GS%Dn^l
// output.writeLong(nPos); LX'US-B.!
output.writeLong(fileSplitterFetch.nStartPos); \=~Ap#Mpc4
output.writeLong(fileSplitterFetch.nEndPos); ~5b %~:
} P@#6.Bb#V
output.close(); {[+gM?
} N8TO"`wdbs
catch(IOException e){e.printStackTrace ();} Lif mYn[
catch(Exception e){e.printStackTrace ();} hV)I C9
} >xN^#$ng}
bUNp>H>L
|%}?*|-
//读取保存的下载信息（文件指针位置） NINiX(
private void read_nPos() 57r)&8
{ >J1o@0tk
try{ ]F~5l?4u#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F 7=-k/k
int nCount = input.readInt(); s0u$DM2
nStartPos = new long[nCount]; %j,Ny}a
nEndPos = new long[nCount]; ?l/rg6mbI'
for(int i=0;i<nStartPos.length;i++) t9}XO M*
{ jn[a23;G)
nStartPos = input.readLong(); pP#?|
nEndPos = input.readLong(); 8"@<s?0\"
} c?d#Bj ?
input.close(); h$!qb'|
} DCm;dh
catch(IOException e){e.printStackTrace ();} C{D2mSS
catch(Exception e){e.printStackTrace ();} R[(,wY_1
} &P;x<7h$t?
g 0L 4
K;95M^C\O*
private void processErrorCode(int nErrorCode) sM-*[Q=_
{ ]1K &U5p
System.err.println("Error Code : " + nErrorCode); `'>>[*06:a
} /c7j@=0
R8KL4g-d
Wi[Y@
//停止文件下载 N P"z
public void siteStop() (#:Si~3
{ mH?hzxa+
bStop = true; 5q<kt{06\
for(int i=0;i<nStartPos.length;i++) ~ 0[K%]]
fileSplitterFetch.splitterStop(); ,uw&)A
u32<=Q[
kxP6#8*:
} L \$zr,=C
} U+ 8[Ia(t
//负责部分文件的抓取 eZv0"FK X
**FileSplitterFetch.java ] !H<vR$8
*/ YcI]_[
package NetFox; M_e!s}F
h3:,Gbyap
s^U^n//
import java.io.*; eD}Ga4
import java.net.*; vD(;VeW[
o]nQo?!
G$Dg*<
public class FileSplitterFetch extends Thread { qUo(hbp
L+u_153
GP[$&8\M
String sURL; //File URL /oI''O%M
long nStartPos; //File Snippet Start Position >A)he!I
long nEndPos; //File Snippet End Position TQ BL!w
int nThreadID; //Thread's ID HG^8&uh]
boolean bDownOver = false; //Downing is over >3ODqRu
boolean bStop = false; //Stop identical [:o#d`^
FileAccessI fileAccessI = null; //File Access interface bUBuJ
3drgB;:g`
HqbTJ!a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?]})Xf.A
{ Y8d%L;b[D
this.sURL = sURL; [;2v[&Po
this.nStartPos = nStart; hOq1"kL
this.nEndPos = nEnd; 6(z.(eT
nThreadID = id; JvG t=v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4uv }6&R
} &@RU}DnvM&
#*~ (
mdk:2ndP
public void run() (d (whlF
{ o;O_N^_W
while(nStartPos < nEndPos && !bStop) {S}/LSNB
{ FPqgncBHK
)j$Bo{
[fb-G5x
try{ w90y-^p%
URL url = new URL(sURL); 3B_S>0H"$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )JjfPb64
httpConnection.setRequestProperty("User-Agent","NetFox"); isaT0__8
String sProperty = "bytes="+nStartPos+"-"; \UiuJ+
httpConnection.setRequestProperty("RANGE",sProperty); bi_R.sfK&
Utility.log(sProperty); wM|-u/9+
M--6oR7
j;'NJ~NZ$
InputStream input = httpConnection.getInputStream(); fpzTv3D=I
//logResponseHead(httpConnection); 0D\FFfs
h.c)+wz/%C
CfVz'
byte[] b = new byte[1024]; 0/%zXp&m
int nRead; rsIjpPa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FY VcL*
{ 4iKT
nStartPos += fileAccessI.write(b,0,nRead); . E.OBn
//if(nThreadID == 1) O[N{&\$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $k!t&G
} Y!SD^Ie7!
Hj5b.fB
JY /Cd6\
Utility.log("Thread " + nThreadID + " is over!"); c~>M7e(
bDownOver = true; ?1[go+56X
//nPos = fileAccessI.write (b,0,nRead); $1w8GI\J
} (;s\Ip0
catch(Exception e){e.printStackTrace ();} *:_.cbo
} v7g-M
} Sd{>(YWx~
Y#Hf\8r,d
9m#`56G`
//打印回应的头信息 }g`A*y;t
public void logResponseHead(HttpURLConnection con) 0z,c6MjM+
{ NE/3aU
for(int i=1;;i++) Z3I<
{ <yIJ$nBx
String header=con.getHeaderFieldKey(i); D L$P
if(header!=null) Lrz>00(*4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <8H`y(S
Utility.log(header+" : "+con.getHeaderField(header)); ;Yi ;2ttW
else Ble <n6
break; QjRVdb>
} hLBX,r)u
} s'i1!GNF B
K}Aaflq
Um*{~=;u
public void splitterStop() Ha;^U/0|
{ >WDb89kC=
bStop = true; R|Ykez!D
} W~gFY#w
n#m )]YQC
iS02uVmBZ
} 1z*]MYU
UP#]n 69y
WM9QC59
/* xH*OEzN
**FileAccess.java %vMi kibI
*//文件访问(定位，写) 3dC8MKPq0
package NetFox; i9+V<'h
import java.io.*; Y]ZOvA5W
qc@CV:
taI])
public class FileAccessI implements Serializable{ :0V<
Z1*y$=D?3[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nIXq2TzJ
RandomAccessFile oSavedFile; Nqy',N
long nPos; (%\N-[yZ
,sXa{U
spgY &OI;
public FileAccessI() throws IOException fMd]P:B
{ F@&q4whaVD
this("",0); BpRQG]L
} u|B\@"0
tOS%.0W5J
QD q2<
public FileAccessI(String sName,long nPos) throws IOException hyFq>XFo
{ ^uC1\!Q1
oSavedFile = new RandomAccessFile(sName,"rw"); hG; NJx-=R
this.nPos = nPos; Hz!+g'R!Gs
oSavedFile.seek(nPos); =]&R6P>
} MiAXbo#\
pT:CvJ
~cQP4 kBD]
public synchronized int write(byte[] b,int nStart,int nLen) 8K7zh.E
{ w=y!|F
int n = -1; nSmYa7
try{ -Z)$].~|t
oSavedFile.write(b,nStart,nLen); 1KAA(W;nq
n = nLen; hekAics6S
} 9kWyO:a_(
catch(IOException e) "pQM$3n(
{ 'BcxKqC
e.printStackTrace (); p~$\@8@
} zH}u9IR3`
vUY?Eb[
B$_F)2%m;
return n; p;U[cGHC
} C.FGi`rrm
1DN,
0A/GWSmF
} }ZlJ
[P`Q_L,+
Vt*Duh+4
/* C5*j0}
**SiteInfoBean.java w'#VN|;;!
*/ i=#r JK=
package NetFox; MuO7_*q'n
u'<Y#bsR#/
&W)ks
public class SiteInfoBean { >/ECLP
t> -cTQm
--dGN.*xb4
private String sSiteURL; //Site's URL QSmE:Y
private String sFilePath; //Saved File's Path hm&{l|u{RU
private String sFileName; //Saved File's Name A|c :&i
private int nSplitter; //Count of Splited Downloading File fI t:eKHr
<~u.:x@ R
hJrxb<9@Y0
public SiteInfoBean() 69`9!heu
{//nSplitter的缺省值为5 \V+$2 :A
//default value of nSplitter is 5 Z"mpE+U*
this("","","",5); U^snb6\5
} VQ$=F8ivG
xEOR\(Z^
acRPKTs H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V89!C?.[]1
{ = K"F!}
sSiteURL= sURL; |&o1i~Y
sFilePath = sPath; @R9
sFileName = sName; fu?>O/Gn/
this.nSplitter = nSpiltter; ;_F iiBk7(
L>).o%(R
'.#KkvE##
} H2zd@l:R
Z>7Oez>
q(\$-Dk.Vv
public String getSSiteURL() 3BKW
{ FJ!N)`[
return sSiteURL; 2Qc&6-;`
} TXH: +mc
~g;(`g
'N,x=1R5
public void setSSiteURL(String value) ygd'Nh!@
{ A&Ut:OiA
sSiteURL = value; qV@xEgW#r
} &dbX>u q
F<Z"W}I+6
Ipb4{A&"\
public String getSFilePath() (=)+as"u9*
{ 0Dc$nL?TqX
return sFilePath; yV$p(+KkS
} ?F(t`0=
5\S)8j `8
RD=!No?
public void setSFilePath(String value) wAVO%8u
{ c)rI[P7Q
sFilePath = value; "P&|e|7
} IE|x+RBD
v)%EG
mu=u!by.E
public String getSFileName() P`-(08t
{ !r.X.C
return sFileName; b1\z&IdC
} nO\|43W
n"@3d.21
^Ac0#oX]M
public void setSFileName(String value) fR_)e:
{ v$+G_@
sFileName = value; _&19OD%
} 8{4I6;e-
)WwysGkqol
CW*6 -q
public int getNSplitter() n!ea)+^
{ '?_I-="Mr
return nSplitter; ^}U{O A
} jMW|B
*q|.H9 K(
9} eIidwK
public void setNSplitter(int nCount) xDRK^nmC
{ UF,T
nSplitter = nCount; w{I60|C]*
} qf4|!UR{
} s ~(qO|d
S8.nM}x
kYPowM
/* 03$Ay_2
**Utility.java B&-;w_K
*/ f>#\'+l'
package NetFox; ir \d8.
wUh'1D<(r
s]U'*?P
public class Utility { CUlANd"
nUd(@@%m
n." j0kc7=
public Utility() B 8C3LP}?
{ :d)@|SR1
XfViLBY( >
d!Y,i!l!
} n)$ q*IN"
d<`Z{"g NS
//线程睡眠 J\m7U
public static void sleep(int nSecond) _.?$~;7
{ 4&$hBn=!
try{ @ mtv2P`
Thread.sleep(nSecond); \DeZY97p%
} N<$uAns
catch(Exception e) Bi?.G7>
{ SV6Np?U
e.printStackTrace (); 2s|[!:L5
} li/IKS)e$
} dgX0\lKpf
+SUQRDF@i
//日志 >jN)9}3>-#
public static void log(String sMsg) s49AF
{ xQWZk`6~L
System.err.println(sMsg); _F,@mQ$!
} # ?}WQP!
9.vHnMcq
!. q*bY
public static void log(int sMsg) 9R'rFI
{ z~z.J]
System.err.println(sMsg); Rqvm%sAi
} X@|
} 2)4{
7Py8!
G78rpp
/* - bFz
**TestMethod.java ZVK;m1?'
*/ (nvSB}?
package NetFox; TyGXDU
7CrWsQl u
\$riwL
public class TestMethod { 0($MN]oZa
z@T;N'EM
o6B!ikz 8
public TestMethod() Vj~R6
{ ///xx/weblogic60b2_win.exe VpTp*[8O
try{ ^[^uDE <
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]<++w;#+x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >MiA|N=
SiteFileFetch fileFetch = new SiteFileFetch(bean); t=A| K
fileFetch.start(); "F)7!e
} IE'OK
catch(Exception e){e.printStackTrace ();} }{]{`\
HYW+,ts'
WmOd1
} :R<,J=+$u
vV"TTzs!
]yCmGt+b
public static void main(String[] args) - DL/Hk_r
{ {_ewc/~
new TestMethod(); ed>_=i
} PJh\U1Z
} d3^LalAp
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