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)); +d[A'&"
} ~?V+^<P
for(int i=0;i<nEndPos.length-1;i++) Q?f%]uGFQ
{ Oz\mIVC#
nEndPos = nStartPos[i+1]; 9uXuV$.
} 9Tgl/}q)
nEndPos[nEndPos.length-1] = nFileLength; [DW}z
} e&Z\hZBb
} \9U4V>p
g/)$-Z)Nu
:$bp4+3>
//启动子线程 c0J=gZiP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x=+R0ny
for(int i=0;i<nStartPos.length;i++) k,EI+lCX
{ '}3m('u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -mSiZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }E01B_T9z
nStartPos,nEndPos,i); u/Os
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Rw]4/
fileSplitterFetch.start(); Bg^k~NX%
} $ae*3L>5M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PGT*4r21
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _3q%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =)56]ki}
nEndPos = " + nFileLength); <O`yM2/pS
// fileSplitterFetch[nPos.length-1].start(); @ljvTgZ(X
b>N)H
OD,"8JF
//等待子线程结束 9Fe(],AzF
//int count = 0; vYh_<Rp5
//是否结束while循环 G;:D6\
boolean breakWhile = false; 4dDDi,)U
~|j:xM(i
S.;>:Dd[K
while(!bStop) wi#]*\N\9
{ yOn +Y
write_nPos(); @w1@|"6vF
Utility.sleep(500); P]bq9!{1
breakWhile = true; m){.{Vn]
N-x~\B!
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for(int i=0;i<nStartPos.length;i++) #A8d@]Ps
{ U @Il:\I
if(!fileSplitterFetch.bDownOver) ,`7;S,f
{ =-M)2&~L~
breakWhile = false; j@c fR
break; 0phO1h]2S)
} SnK j:|bV
} !P7##ho0
if(breakWhile) r7tN(2;5
break; 20hF2V
lFWN[`H
{}?;|&_
//count++; |Rr^K5hmD
//if(count>4) o.tCw\M$g
// siteStop(); Rd5ni2-nve
} =d/\8\4
Lc>9[!+#
VjU;[
System.err.println("文件下载结束！"); <!.'"*2
} r`]&{0}23
catch(Exception e){e.printStackTrace ();} QK0
} 0\tk/<w2
QN[-XQ>Xt
_m!TUT8o
//获得文件长度 gY AXUM,
public long getFileSize() g-=)RIwm
{ $|v_ pjUu]
int nFileLength = -1; rs01@
try{ Xtqjx@ye
URL url = new URL(siteInfoBean.getSSiteURL()); &z;;Bx0s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M.K-)r,
httpConnection.setRequestProperty("User-Agent","NetFox"); n{F$,a
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z`-?5-a]I
int responseCode=httpConnection.getResponseCode(); bS{7*S
if(responseCode>=400) wiWpzJz
{ DpIv <m]
processErrorCode(responseCode); ! /Z{uy
return -2; //-2 represent access is error u49zc9
} i^9PiP|U
!j8h$+:K
yp=Hxf
String sHeader; %dTkw+J
~je#gVoUR
%iWup:
for(int i=1;;i++) &6A'}9Ch
{ D'aq^T'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]=p@1
//Utility.log(in.readLine()); R}F0_.
sHeader=httpConnection.getHeaderFieldKey(i); f[3DKA
if(sHeader!=null) #Ag-?k
{ &?^S`V8R*
if(sHeader.equals("Content-Length")) 0uzm@'^
{ Efi@hdEV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |pJ)w
break; )/H=m7}1h
} Ktg{-Xl
} 7N"$~UfC
else 9l2,:EQ*
break; X3#/|>
} *6~ODiB
} ;cl\$TDL
catch(IOException e){e.printStackTrace ();} _^Lv8a3(O
catch(Exception e){e.printStackTrace ();} 6_/691
h+Km|
ghm5g/
Utility.log(nFileLength); |du@iA]dP
h)BRSs?v_D
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return nFileLength; {J q[N}
} kf+]bV
kH1hsDe|&y
D/jB.
//保存下载信息（文件指针位置） 9;s:Bo
private void write_nPos() 2#l<L>#
{ /]_T
try{ -frmvNJ F
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7PO3{I
output.writeInt(nStartPos.length); R%o:'-~
for(int i=0;i<nStartPos.length;i++) qEr2Y/:i"
{ }\}pSqW
// output.writeLong(nPos); 1VK?Svnd
output.writeLong(fileSplitterFetch.nStartPos); BL<.u
output.writeLong(fileSplitterFetch.nEndPos); _x 'R8/
} Zpg/T K
output.close(); |WH'aGG
} 3}=r.\]U
catch(IOException e){e.printStackTrace ();} PHl{pE*
catch(Exception e){e.printStackTrace ();} [hA%VF.9
} ?D-1xnxep
G\G TS}u[
9Y!N\-x`
//读取保存的下载信息（文件指针位置） %`%oupqm+
private void read_nPos() c^vPd]Ed
{ Mg;%];2Nt
try{ D].!u{##
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }]_/:KUt
int nCount = input.readInt(); )z-)S
nStartPos = new long[nCount]; zWpJ\/k~
nEndPos = new long[nCount]; ;EbGW&T
for(int i=0;i<nStartPos.length;i++) %JM:4G|q
{ n4Nb,)M
nStartPos = input.readLong(); R>SS\YC'X
nEndPos = input.readLong(); :+{G|goZ*
} ~>&7~N8
input.close(); [G2@[CtY1
} /!;oO_U:#
catch(IOException e){e.printStackTrace ();} ^T@ (`H4@
catch(Exception e){e.printStackTrace ();} 73B,I 0U
} >nV~5f+
=!T@'P?
i2KN^"v?N
private void processErrorCode(int nErrorCode) d4KTwn5g
{ u~n*P``{
System.err.println("Error Code : " + nErrorCode); Qd;P?W6
} )9F-h8 &"
wBZ=IMDu\
twElLOE
//停止文件下载 >QO^h<.>
public void siteStop() 1Q\P] -
{ 0JzH dz
bStop = true; [ZC]O2'
for(int i=0;i<nStartPos.length;i++) D\|$!i}
fileSplitterFetch.splitterStop(); ly"Jl8/<
.GcIwP'aU-
FJ0Ity4u6
} %B?@le+%
} {$D[l hj
//负责部分文件的抓取 +GCN63nX
**FileSplitterFetch.java ]-[M&i=+&
*/ K"u-nroHW
package NetFox; U-Ia$b-5!
Pyh+HD\
wZ6D\I
import java.io.*; 4x7(50hp#
import java.net.*; S3#NGBZ/
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ZrY#B8
public class FileSplitterFetch extends Thread { V]I@&*O~r
9U[Gh97Sf
PL$*)#S"$
String sURL; //File URL (Z:(f~;
long nStartPos; //File Snippet Start Position _vOV(#q2a
long nEndPos; //File Snippet End Position p7 s#j
int nThreadID; //Thread's ID =KQQS6
boolean bDownOver = false; //Downing is over ]0N'Wtbn
boolean bStop = false; //Stop identical =&+]>g{T
FileAccessI fileAccessI = null; //File Access interface m$N`Xj
,TeJx+z^
\s_lB~"P!3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W|@7I@@$"
{ aq~>$CHa
this.sURL = sURL; 6Gt~tlt:L
this.nStartPos = nStart; zED#+-7
this.nEndPos = nEnd; )ph**g
nThreadID = id; 5mzOr4*0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6 3TeTGp$
} WFWQ;U{|
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'?| (QU:)F
public void run() 9Z?P/ o
{ .'`7JU#{
while(nStartPos < nEndPos && !bStop) >?Y)evW
{ q/T(s
1D2Uomd(
C]@v60I
try{ *"cK_MH/o
URL url = new URL(sURL); 'u9,L FO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JFOto,6L:
httpConnection.setRequestProperty("User-Agent","NetFox"); [tN^)c`s/
String sProperty = "bytes="+nStartPos+"-"; bBx.snBK
httpConnection.setRequestProperty("RANGE",sProperty); 7RXTQ9BS
Utility.log(sProperty); @|I:A
b5!\"v4c
7JC^+rk
InputStream input = httpConnection.getInputStream(); C\-Abqc
//logResponseHead(httpConnection); Lj]I7ICNh
[^N8v;O
T >pz/7gb
byte[] b = new byte[1024]; \R!.VL3Tx$
int nRead; z-9@K<`H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ywQ>T+
{ D8S?xK7[
nStartPos += fileAccessI.write(b,0,nRead); .`I;qF
//if(nThreadID == 1) ~*R:UTBtw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L&D+0p^lI
} :S['hBMN
+jpaBr-O#
Kmk}Yz
Utility.log("Thread " + nThreadID + " is over!"); N3M:|D
bDownOver = true; R,Gr{"H
//nPos = fileAccessI.write (b,0,nRead); f+}Rj0A
} R,3E_me"}
catch(Exception e){e.printStackTrace ();} @M]uUL-ze
} *.'9eC0s
} YwbRzY-#F
B~%'YQk
]1 V,_^D
//打印回应的头信息 oK-T@ &-
public void logResponseHead(HttpURLConnection con) \IL;}D{
{ \BRxdK'
for(int i=1;;i++) $`KddW0_
{ N}$$<i2o
String header=con.getHeaderFieldKey(i); tEU}?k+:j)
if(header!=null) Ou26QoT9XI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 98c##NV(7|
Utility.log(header+" : "+con.getHeaderField(header)); rLkUIG
else }Q }&3m~g
break; -dj9(~?^
} TT85G&#
} nZ4JI+Q)~
$ 8"we
/J0YF
public void splitterStop() |JUb 1|gi
{ S.: m$s
bStop = true; qw#wZ'<n
} yN'<iTh
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[lU0TDq
} "7> o"FQ
gI~4A,
I.4o9Z[?
/* _f"HUKGN
**FileAccess.java ;s^br17z~
*//文件访问(定位，写) : ~RY
package NetFox; ^|b]E
import java.io.*; ?Aq \Gr
=XRTeIZ
+vDEDOS1
public class FileAccessI implements Serializable{ a/4!zT
sI/]pgt2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zL^`r)H
RandomAccessFile oSavedFile; x|7vN E=Q
long nPos; n?UFFi+a
Wzn!BgxRr
=do*(
public FileAccessI() throws IOException A`#/:O4|f
{ f;PPB@ :`$
this("",0); 5W Z9z-6
} k@[P\(a3b
u|.c?fW'3
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public FileAccessI(String sName,long nPos) throws IOException "X[sW%# F
{ ,k9@%{4 l
oSavedFile = new RandomAccessFile(sName,"rw"); i[+cNJ|$B0
this.nPos = nPos; nfldj33*
oSavedFile.seek(nPos); Np.] W(
} 9s.x%m,
tc|`cB3f
rnkq.
public synchronized int write(byte[] b,int nStart,int nLen) hja;d1yH
{ `U.VfQR:
int n = -1; ~xp(k
try{ O(_a6s+m
oSavedFile.write(b,nStart,nLen); 342m=7lK
n = nLen; =V[ey
} :xBG~D
catch(IOException e) !5wuBJ0
{ 9B&fEmgEc?
e.printStackTrace (); z5> {(iY;,
} .{=|N8*py8
x!i(M>P
./KXElvQ%
return n; `Z'h[-2`
} d3IMQ_k
D)_67w|u|
"44A#0)B'l
} iC.k8r+~
H}p5qW.tH:
{,9^k'9
/* )tD[Ffvr
**SiteInfoBean.java J^Mq4&
*/ wuV*!oefo
package NetFox; }JWLm.e
ov9+6'zya
f6*6*=
public class SiteInfoBean { c@&`!e
W>HGB
B(zcoWQ*B
private String sSiteURL; //Site's URL O'i!}$=g
private String sFilePath; //Saved File's Path O,c}T7A'?w
private String sFileName; //Saved File's Name X9S`#N
private int nSplitter; //Count of Splited Downloading File )*CDufRFz
Ocp`6Fj
BB.^[:,dA
public SiteInfoBean() ~x #RIt
{//nSplitter的缺省值为5 gx55.}
//default value of nSplitter is 5 "dItv#<:}
this("","","",5); fK?/o]vq
} ';>A=m9(4%
4owM;y
|Q\O% cb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %p(!7FDE2n
{ 4[P]+Z5b+
sSiteURL= sURL; |ler\"Eu
sFilePath = sPath; ~w,c6Z
sFileName = sName; brpsZU
this.nSplitter = nSpiltter; CBrC
;J&p17~T9
U%?
} 6 *GR_sMm
%%c1@2G<
6oA2"!u^w
public String getSSiteURL() a:V2(nY
{ +k<0:Fi
return sSiteURL; 7/>#yR
} [/+}E X
mFa%d8Y
cmu|d
public void setSSiteURL(String value) sPxDo?1x-
{ u6lcl}'
sSiteURL = value; E8LZ% N#
} ~_GW
"R5! VV
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public String getSFilePath() N\nxo0sl
{ eJ"je@vvrK
return sFilePath; U-6pia/o
} a@v}j&
iU1yJ=
V\6V&_
public void setSFilePath(String value) NSV;R~"
{ O}Mu_edM
sFilePath = value; 7mT iO?/y<
} NQu.%=
bSvr8FY3d
aJ3.D
public String getSFileName() 9,J^tN@^
{ S"Z.M _
return sFileName; d#vo)>
} $sS;#r0
!V~,aoKTj
5==hyIy
public void setSFileName(String value) ?qt.+2:
{ *P; cSx?2
sFileName = value; vAt]N)R
} |EZ\+!8N:{
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public int getNSplitter() O =gv2e
{ 3k_bhK zI
return nSplitter; \3XG8J
} KSgYf;
!eP)"YWI3
Cw$7d:u
public void setNSplitter(int nCount) r>,s-T!7
{ {7Qj+e^
nSplitter = nCount; Y2d(HD@
} LM2S%._cj;
} z~($ "
Em]2K:
C;\R 62'
/* ^hRx{A
**Utility.java UNF@%O4_T
*/ MJugno
package NetFox; 4r tNvf5`
y{g"w
YwU[kr-i
public class Utility { S>;+zVF]
K:L_y1!T
oXFo
public Utility() ^|UD&6 dx
{ :v B9z
r0/aw
P<C=9@`!
} _@@.VmZL
`6RR/~kP(
//线程睡眠 b<27XZ@
public static void sleep(int nSecond) <^(>o
{ &HB!6T/
try{ .r~M7 I
Thread.sleep(nSecond); Qpocj:
} KXT9Wt=
catch(Exception e) VM}7 ~
{ &2sfu0K
e.printStackTrace (); }!QVcu"+t/
} ["WWaCcx
} ]XjL""EbC
$&X-ay o
//日志 Cg3 d
public static void log(String sMsg) Mhu|S)hn
{ N oRPvFv
System.err.println(sMsg); -T2w?|
} yrG=2{I
&3f^]n!@
VQ8Q=!]
public static void log(int sMsg) Jd28/X5&
{ PW+B&7{
System.err.println(sMsg); zALtG<_t
} ihd^P]
} IG90mpLX
G=PX'dS
c@Xb6z_>
/* W H%EC$
**TestMethod.java \k3EFSm
*/ ^{a_:r"
package NetFox; 1ZY~qP+n+
v}TFM
<UwYI_OX
public class TestMethod { Gq-~zmg
zy`T! $
5'/ff=
public TestMethod() 0i(c XB
{ ///xx/weblogic60b2_win.exe hv*XuT/
try{ 5c$\DZ(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nh+Hwj#(x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `L%<3/hF
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~\+Bb8+hpJ
fileFetch.start(); 7Y5.GW\^
} JnLF61
catch(Exception e){e.printStackTrace ();} %+oqAYm+s
o37D~V;
~l}\K10L*
} VIg6'
B+z>$6
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public static void main(String[] args) 9.BgsV .
{ 7^<6|>j4
new TestMethod(); ;;+h4O )
} G5ShheZd
} &gcZ4gpH
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