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)); KFhn}C3 i
} YfalsQ8
for(int i=0;i<nEndPos.length-1;i++) q!TbM"
{ =4D_-Q
nEndPos = nStartPos[i+1]; $P-m6
} +,[3a%c)H
nEndPos[nEndPos.length-1] = nFileLength; M~Slc*_%
} g#:XN
} GW#kaqC1
:2My|3H\
z]YhQIU4n8
//启动子线程 ob7_dWAG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'k67$H
for(int i=0;i<nStartPos.length;i++) s,v#lJ]d0W
{ EVL;"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /$z@_U[L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v(h Xk]S
nStartPos,nEndPos,i); =s]{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9vTQ^*bm
fileSplitterFetch.start(); 8_m9CQ6 i
} tb{{oxa,k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QT$1D[>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c #!6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $ddYH
nEndPos = " + nFileLength); I3Lsj}69
// fileSplitterFetch[nPos.length-1].start(); "k|`xn
qtN29[x
I`TD*D
//等待子线程结束 !S!03|
//int count = 0; @qDrTH]5
//是否结束while循环 @,&m`qzd+
boolean breakWhile = false; ?GarD3#A
D.o|($S0
3R*@m
while(!bStop) X-,y[ )
{ LwPM7S~ *
write_nPos(); ewG21 q$
Utility.sleep(500); h /QP=Zd
breakWhile = true; ug,|'<G+
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?v8k& q^q
for(int i=0;i<nStartPos.length;i++) "V0:Lq
{ wKlCx
if(!fileSplitterFetch.bDownOver) "T u[n\8
{ $0SZlq>En
breakWhile = false; ebe@.ZVSi
break; -l@W)?$
} b=UMoWS
} 4.B*B3
if(breakWhile) vx@p;1RU`
break; l&Ghs@>Kl
dO;vcgvb
xg^^@o
//count++; @%nUfG7TQ
//if(count>4) xJLO\B+gM
// siteStop(); TY\"@(Q|G
} <57l|}8
/VO@>Hoh
rOHW
System.err.println("文件下载结束！"); TQd FC\@f"
} Q|KD/s??
catch(Exception e){e.printStackTrace ();} &]F|U3
} ><MgIV
Gy6qLM
}!<cph
//获得文件长度 w a<C*o
public long getFileSize() {U '&9_y
{ %Dls36F
int nFileLength = -1; 2 `h!:0
try{ B;]5,`#!
URL url = new URL(siteInfoBean.getSSiteURL()); )UZ0gfx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x5z4Yv^ m
httpConnection.setRequestProperty("User-Agent","NetFox"); OG+r|.N;
CPNN!%-
v6-~fcX0G
int responseCode=httpConnection.getResponseCode(); 'xZPIj+
if(responseCode>=400) K}<!{/fi)
{ %)Uvf`Xhh4
processErrorCode(responseCode); Z)i1?#
return -2; //-2 represent access is error ([CnYv
} x<j"DS}S)D
?U/Wio$@
`6N-MsP
String sHeader; Y+u-J4bj
UxcDDa/j2T
{dA ~#fW<
for(int i=1;;i++) BH0#Q5
{ ho]!G498
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1|WpKaMoq
//Utility.log(in.readLine()); sMS9!{A
sHeader=httpConnection.getHeaderFieldKey(i); &<V_[Wh"
if(sHeader!=null) ;#yu"6{
{ QS [B
if(sHeader.equals("Content-Length")) ?hJsN
{ bjPbl2K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T E&Q6
break; vMX6Bg8
} dHq )vs,L
} ow+Dd[i
else EdAR<VfleA
break; 3hXmYz(
} k g,ys4
} hHc^ZA
catch(IOException e){e.printStackTrace ();} (OyY_`
catch(Exception e){e.printStackTrace ();} f>)Tq'
QPe9s[Y
]fADaw-R
Utility.log(nFileLength); {eswe
:DMHezaU
*pTO|x{
return nFileLength; KM5DYy2 A6
} +dgo-)kP(_
v*H &F
:#\B {)(
//保存下载信息（文件指针位置） (' Ko#3b
private void write_nPos() `$V[;ld(mz
{ Oh/b?|imG
try{ :q>oD-b$}
output = new DataOutputStream(new FileOutputStream(tmpFile)); 02W4-*)
output.writeInt(nStartPos.length); xZP>g
for(int i=0;i<nStartPos.length;i++) >C:"$x2"#(
{ Z;fm;X%4
// output.writeLong(nPos); 0Z A#T:4
output.writeLong(fileSplitterFetch.nStartPos); '9 *|N=
output.writeLong(fileSplitterFetch.nEndPos); c{,y{2c]LT
} =X`]Ct8Z
output.close(); /NW>;J}C
} Im?= e
catch(IOException e){e.printStackTrace ();} tt7PEEf
catch(Exception e){e.printStackTrace ();} gVa+.x]
} {\svV 0)~
-7k|6"EwM
K$<`4#i
//读取保存的下载信息（文件指针位置） Ig02M_
private void read_nPos() =XMD+
{ hJ;f1dZ7}
try{ oEenm\ZI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Txt%nzIu
int nCount = input.readInt(); AB2mt:^
nStartPos = new long[nCount]; :Hzz{'
nEndPos = new long[nCount]; P /c Q1
for(int i=0;i<nStartPos.length;i++) +~w?Xw,
{ '9-axIj70
nStartPos = input.readLong(); O&#S4]Y
nEndPos = input.readLong(); `;5VH]V
} rL%]S&M9
input.close(); >@)*Sn9"
} HJfQ]p'nK2
catch(IOException e){e.printStackTrace ();} QiTR-M2C!
catch(Exception e){e.printStackTrace ();} abROFI5.L
} U]V3DDN
@V* ju
8h&oSOkQk,
private void processErrorCode(int nErrorCode) hv$uH7Fz
{ fiE>H~
System.err.println("Error Code : " + nErrorCode); z^gQ\\,4
} `1fJ:b/M
H.YIv50E
4|> rwQ~t
//停止文件下载 #Mj$o;SX
public void siteStop() ,7^d9v3t
{ n|70x5Z?}J
bStop = true; $` Z>Lm*
for(int i=0;i<nStartPos.length;i++) @<D'-mMt
fileSplitterFetch.splitterStop(); tt6. jo
UAsF0&]
MAE7A"la
} ;x:k-s2-
} 6R1wn&8
//负责部分文件的抓取 ku/\16E/k
**FileSplitterFetch.java (dzH3_U
*/ wr$cK'5ZL
package NetFox; k^H0b\hYY
h8f!<:rTS
'1W!xQ}E
import java.io.*; r{t.c?/
import java.net.*; MV"E?}0
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>Z#uFt0<Pm
public class FileSplitterFetch extends Thread { VHXI@UT*
#4P8Rzl$/
>I$B=
String sURL; //File URL K#qoR/:
long nStartPos; //File Snippet Start Position &`9j)3^J.
long nEndPos; //File Snippet End Position e>L5.~i
int nThreadID; //Thread's ID A",eS6
boolean bDownOver = false; //Downing is over ]b4pI*:$I
boolean bStop = false; //Stop identical Ik`O.Q.}
FileAccessI fileAccessI = null; //File Access interface <8u>_o6
o3Mf:;2cC
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k$ZRZ{ E+
{ )Rjb/3*!
this.sURL = sURL; 99<4t$KH
this.nStartPos = nStart; E%<w5d.lq
this.nEndPos = nEnd; v<L=!-b^
nThreadID = id; nd.57@*M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^I]LoG:
} P@qMJ}<j
7~_{.f
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public void run() `wNm%*g
{ ).pO2lLF4
while(nStartPos < nEndPos && !bStop) Y\.-v\uJu
{ r?fH &u
FoE|Js
xDR9_
try{ :]vA2
URL url = new URL(sURL); iV5}U2Vh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rw{$L~\
httpConnection.setRequestProperty("User-Agent","NetFox"); IikG/8lP
String sProperty = "bytes="+nStartPos+"-"; V?OuIg%=:
httpConnection.setRequestProperty("RANGE",sProperty); {DU"]c/S
Utility.log(sProperty); q_cC7p6t
?nQ_w0j
_b>F#nD,'%
InputStream input = httpConnection.getInputStream(); ):e+dt
//logResponseHead(httpConnection); ,Z^Ca15z
2zz,(RA
ov8 ByJc
byte[] b = new byte[1024]; ?Phk~ jE
int nRead; kW#S]fsfU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `YPe^!`$
{ ]JH64~a
nStartPos += fileAccessI.write(b,0,nRead); 9/#0?(K8
//if(nThreadID == 1) ?N:B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rvW!7-R
} *D2Nm9sl
t5xb"F
Rv98\VD"
Utility.log("Thread " + nThreadID + " is over!"); 85'nXYN{d
bDownOver = true; Y=r!2u6r~
//nPos = fileAccessI.write (b,0,nRead); *RBV'b
} )D;*DUtMVm
catch(Exception e){e.printStackTrace ();} ~e{H#*f&1/
} Rq) 0i}F
} JjQ8|En
T'E] i!$
2+z1h^)W
//打印回应的头信息 )B6# A0
public void logResponseHead(HttpURLConnection con) uS~#4;R
{ 4CLsY n?
for(int i=1;;i++) n=q=zn;
{ 7AFE-'S
String header=con.getHeaderFieldKey(i); WZq,()h
if(header!=null) 98GlhogWt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3?Lgtkb8
Utility.log(header+" : "+con.getHeaderField(header)); *.oKI@
else W;4Lkk$
break; Ejv%,q/T(
} cph~4wCS[U
} -;$nb~y
;J]25j]]
NetYg]8`
public void splitterStop() ^=^$tF
{ _K'7(d0z
bStop = true; N>0LQ MI
} k'Gw!p}
%<ic%gt`#
v9=}S\=Cd
} s.VA!@F5
$/+so;KD
} ~| k
/* ^-hErsK
**FileAccess.java @D~B{Hg
*//文件访问(定位，写) ,9d9_c.T
package NetFox; /%!~x[BeJ>
import java.io.*; ND5$bq Nu?
\@K~L4>
;$7v%Ls=
public class FileAccessI implements Serializable{ nU2V]-qY
b0rX QMu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NgVR,G|1
RandomAccessFile oSavedFile; |f\D>Y%)
long nPos; eZH~je{1
x0A7O
/_)l|<k+V
public FileAccessI() throws IOException IxOc':/jY
{ EiWd+v,QJQ
this("",0); $ KB
} )T1iN(Z
}^Gd4[(,g
:_xh(W+2<
public FileAccessI(String sName,long nPos) throws IOException &$=!dA
{ .IgRY\?Q
oSavedFile = new RandomAccessFile(sName,"rw"); K*Ks"Vx
this.nPos = nPos; 'H|~u&?
oSavedFile.seek(nPos); w^HjZV
} Qqc]aVRF
O-#TZ
?,)"~c$hZ
public synchronized int write(byte[] b,int nStart,int nLen) oh~:,
{ M&KyA
int n = -1; +Rwx%=
try{ wfR&li{
oSavedFile.write(b,nStart,nLen); A_R!uRD8-
n = nLen; ys8Q.oBv_`
} )&,{?$.
catch(IOException e) Qs9OC9X1
{ +&5'uAe
e.printStackTrace (); }Cj8
} d(;4`kd*N
D."=k{r.
/[=E0_t+
return n; I[d]!YI}F
} <41ZZ0<EwY
NmpnJu|8
fDh]tua
} .tnkT;T
;a r><w
Elb aFbr
/* ,DQjDMjrf
**SiteInfoBean.java z-r2!^q27
*/ r2\c'9uH
package NetFox; s^hR\iY
eGL<vX
tg\|?
public class SiteInfoBean { 2eb1lJdS
3<:jx~y>
eSfnB_@x2
private String sSiteURL; //Site's URL Y@uh[aS!
private String sFilePath; //Saved File's Path )C~9E 5E
private String sFileName; //Saved File's Name )nfEQ)L;h}
private int nSplitter; //Count of Splited Downloading File Am"(+>W21
YcDe@Zuwn
@S^ASDuQU7
public SiteInfoBean() {ci.V*:"
{//nSplitter的缺省值为5 `@Oa lg
//default value of nSplitter is 5 +ulagE|7
this("","","",5); !*{q^IO9v&
} =(o']ZaaA
ezm&]F`
n3KI+I%nQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZZxk]D<
{ vFv3'b$;G
sSiteURL= sURL; I&VTW8jB
sFilePath = sPath; )[Z!*am
sFileName = sName; lioc`C:
this.nSplitter = nSpiltter; Dw6fmyJ:
F3Maqr y
"i^ GmVn
} eiVC"0-c}
aZS7sV28
g>JLDQdc
public String getSSiteURL() ;i<jhNA
{ ?-)I+EAnE
return sSiteURL; Na{Y}0=^y
} L2UsqVU
1q7tiMvV-
ino:N5&;;
public void setSSiteURL(String value) YJeyIYCs<
{ #5} wuj%5
sSiteURL = value; YJV%a
} .a'f|c6
soRv1)el
^teq[l$;
public String getSFilePath() 8' DW#%
{ [iP#VM-N
return sFilePath; Of,2Q#oji
} aB~S?.l
C1kYl0zR[
<ABX0U[*
public void setSFilePath(String value) AIYmS#V1W2
{ $sHP\{
sFilePath = value; )!:sFa 1
} c2nKPEX&5
zAzP,1$?
mHc>"^R
public String getSFileName() j=RRfFg)
{ o\b-_E5"?
return sFileName; 2_^aw[-
} w obgu
MK#wut
V~G`kkNy
public void setSFileName(String value) hj%ye~|~
{ 9;.(u'y|
sFileName = value; D\dWt1n
} b;sVls
YyAJ m^o
"TyJP[/
public int getNSplitter() u$#Wv2|mk
{ q[q?hQ/b
return nSplitter; B%CTOi
} CAq/K?:8
`.jzuX
b//B8^Eong
public void setNSplitter(int nCount) x+8_4>,>Y7
{ afBE{
nSplitter = nCount; Ysq'2
} H,fZ!8(A_)
} )L{ghy
^DeERB
R0ID2:i]F
/* 58\&/lYW
**Utility.java W&*f#E
*/ }D411228
package NetFox; jp8@vdRg
-i0(2*<
o1W:ox?kO
public class Utility { v\16RD
O/AaYA&
xsd_Uu*
public Utility() (wDm*bZ*
{ {'?)FX*W
('wY9kvL&
?Nf>]|K:Q
} C2LL|jp*
An;MVA
//线程睡眠 5pr"d@.
public static void sleep(int nSecond) +/,icA}PI
{ @SZM82qU2z
try{ @1.QEyXG
Thread.sleep(nSecond); SDu#Yt&mhh
} aRG2@5
catch(Exception e) L pR''`2BT
{ p&+;w
e.printStackTrace (); 5^']+5_vb
} *.L81er5~
} +a-6Q ~
VE+IKj!VG0
//日志 &%})wZ+Dj
public static void log(String sMsg) m'P1BLk
{ J)P$2#
System.err.println(sMsg); \fA{1
} * #jsgj[
| N0Z-|
q0f3="
public static void log(int sMsg) ^O^l(e!3
{ HGm 3+,
System.err.println(sMsg); 6qcO?U
} @-UL`+
} .>Ljnk
DXz}YIEC
H*#s }9=kZ
/* fRg`UI4w}
**TestMethod.java I%- " |]$
*/ =FE|+!>PA
package NetFox; mM`wITy
6-?66gmT
K>*a*[t0Sy
public class TestMethod { V&-~x^JK
M\yT).>z
pZ/>[TP(%F
public TestMethod() ': N51kC
{ ///xx/weblogic60b2_win.exe FQ g~l4WX
try{ 9Xx's%U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m(pE5B(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jqPkc28
SiteFileFetch fileFetch = new SiteFileFetch(bean); =bEda]
fileFetch.start(); I\YV des#
} PO6&bIr
catch(Exception e){e.printStackTrace ();} W5SJ^,d)J
|V<h=D5W
035rPT7-2-
} v|U(+O
ZDbc
rn<PR*
public static void main(String[] args) /yM:|`tT
{ Z!hafhcX
new TestMethod(); um9_ru~
} T49zcJf;
} g!-,]
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