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)); PxCl]~v
} oW\7q{l2)
for(int i=0;i<nEndPos.length-1;i++) bC,M&<N
{ McMK|_H
nEndPos = nStartPos[i+1]; *j|Tm7C
} PY3Vu]zD
nEndPos[nEndPos.length-1] = nFileLength; D;#Yn M3
} QP-<$P;~
} {D_4~heF
7;#dX~>@{
t&?v9n"X
//启动子线程 PtVNG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |jCE9Ve#
for(int i=0;i<nStartPos.length;i++) U*Q5ff7M6"
{ wx?{|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h"Yqm"U/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }'M1(W
nStartPos,nEndPos,i); e|+;j}^C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DF&jZ[##
fileSplitterFetch.start(); rF j)5~
} )9sr,3w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U"R.!=v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E0?\DvA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h ?qYy$
nEndPos = " + nFileLength); <t|9`l_XW
// fileSplitterFetch[nPos.length-1].start(); 7g<`wLAH
)PZ}^Fa
N55=&-p
//等待子线程结束 +cOI`4`$
//int count = 0; :DF4g=
//是否结束while循环 ^OcfM_4pN
boolean breakWhile = false; $@f3=NJ4k
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o>,z %+
while(!bStop) TD=/C|
{ 71m-W#zyA
write_nPos(); es(LE/`e
Utility.sleep(500); JFk|Uqs(
breakWhile = true; h.+&=s!Nsy
_e@qv;*
7JwWM2N?V
for(int i=0;i<nStartPos.length;i++) vi.AzO
{ ~ M>zO#U6
if(!fileSplitterFetch.bDownOver) Xm[r#IA
{ =y(YMWGS
breakWhile = false; Jn[ K0GV
break; 5pyvs;As
} 5J#gJFA
} =FJ9wiL
if(breakWhile) *A9{H>Vq
break; %v)'`|i
O]LuL&=s y
!P^$g R
//count++; MifgRUe
//if(count>4) s!!t
// siteStop(); =5_F9nk-
} PC7.+;1
B148wh#r
`.-k%2?/
System.err.println("文件下载结束！"); Ln%_8yth
} F"TI9ib
catch(Exception e){e.printStackTrace ();} }$c($
} D>^ix[:J
qtwmTT)
Kj|F
//获得文件长度 #]HjP\C
public long getFileSize() ? bg pUv
{ SF=|++b1f
int nFileLength = -1; >-+X;0&
try{ Cx'=2Y7
URL url = new URL(siteInfoBean.getSSiteURL()); kx(:Z8DX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VQx-gm8}!
httpConnection.setRequestProperty("User-Agent","NetFox"); P(+ar#,G
Ym2m1
54j $A
int responseCode=httpConnection.getResponseCode(); :Lzj'Ij
if(responseCode>=400) s'=]a-l~
{ XdVC>6
processErrorCode(responseCode); Y }d>%i+
return -2; //-2 represent access is error 5h7DVr!
} }X:r:{r
S60`'!y
P.J}\;S T
String sHeader; RIc<
yiA\$mtO
41D[[Gh
for(int i=1;;i++) O]!DNN
{ >n\Q[W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n_2LkW<?
//Utility.log(in.readLine()); <v^.FxId
sHeader=httpConnection.getHeaderFieldKey(i); `<Nc Y*
if(sHeader!=null) &bx,6dX
{ 1S#bV} !
if(sHeader.equals("Content-Length")) ]`m5!V_Y
{ |(g2fByDf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3=I Q
break; Q+N @j]'
} Ob+c*@KiW
} <[~M|OL9q,
else <O&s 'A[
break; C`K/ai{4
} _<Tz1>j=
} mL+ps x+
catch(IOException e){e.printStackTrace ();} O-YE6u
catch(Exception e){e.printStackTrace ();} z05pVe/5
q[g^[~WM#
.YbD.{]D
Utility.log(nFileLength); Wc[)mYOSuO
h2K
ibL;99#
return nFileLength; ]~,'[gWb
} >MLqOUr#
7c7SU^hD
4Qs#ws])
//保存下载信息（文件指针位置） Ado>)c"*y1
private void write_nPos() C%h_!z":
{ iLei-\w6y
try{ fN;y\!q5
output = new DataOutputStream(new FileOutputStream(tmpFile)); SY.V_O$l}
output.writeInt(nStartPos.length); ps[rYy
for(int i=0;i<nStartPos.length;i++) 7IRn
{ aqgSr|
// output.writeLong(nPos); dXQWT@$y!E
output.writeLong(fileSplitterFetch.nStartPos); >d|W>|8e
output.writeLong(fileSplitterFetch.nEndPos); n"vI>_|G
} s RB8 jY
output.close(); 4`B:Mq&j
} 0jq#,p=l;
catch(IOException e){e.printStackTrace ();} HH+XEMP/g
catch(Exception e){e.printStackTrace ();} J<D =\
} +`xp+Q
R8_qZ;t:z
420K fVA
//读取保存的下载信息（文件指针位置） -lHJ\=
private void read_nPos() v?J2cL
{ Fej$`2mRH
try{ =Vfj#WL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H.e@w3+h
int nCount = input.readInt(); $U1'n@/J
nStartPos = new long[nCount]; -\vq-n
nEndPos = new long[nCount]; X^`ld&^*({
for(int i=0;i<nStartPos.length;i++) wlJ_,wA
{ C" {j0X`
nStartPos = input.readLong(); dpS
nEndPos = input.readLong(); _*_zyWW_j
} 2]l*{l^ Bl
input.close(); t+ @F"[j
} !&kOqc5:t<
catch(IOException e){e.printStackTrace ();} #&^+hx|
catch(Exception e){e.printStackTrace ();} 1=>$c
} (s*}=
9;jfg|x1[
Ek:u[Uw\
private void processErrorCode(int nErrorCode) $%<gp@Gz
{ x:(e:I8x(
System.err.println("Error Code : " + nErrorCode); R_csKj
} '5IJ;4k
F+X3CB,f
-kkXyO8js
//停止文件下载 DWDe5$^{
public void siteStop() K%;O$ >
{ $JOIK9+3z#
bStop = true; /*[a>B4-q
for(int i=0;i<nStartPos.length;i++) m&2m' =(
fileSplitterFetch.splitterStop(); d7@ N~<n
j_Fr3BWS
D:f#
} M9MEQK
} dg-pwWqN
//负责部分文件的抓取 ?r/7:
**FileSplitterFetch.java ls=<c<
*/ XHW{EVcF
package NetFox; Zhw _L
wvfCj6}S&
.!&YO/
import java.io.*; GYj`-t
import java.net.*; iS{)Tll}&
:]x)lP(3E
REa%kU
public class FileSplitterFetch extends Thread { oY{*X6:6<
KxvT}"k
<ioX|.7ZX
String sURL; //File URL #)XO,^s.
long nStartPos; //File Snippet Start Position t.m $|M>
long nEndPos; //File Snippet End Position ar{Yq
int nThreadID; //Thread's ID 2)G ZU
boolean bDownOver = false; //Downing is over E-r/$&D5mP
boolean bStop = false; //Stop identical Dq\#:NnKvx
FileAccessI fileAccessI = null; //File Access interface 1 %*X,E
X(bb1
'oo]oeJ-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3o/f#y
{ 9t=erhUr
this.sURL = sURL; -WEiY
this.nStartPos = nStart; <>-UPRwqI
this.nEndPos = nEnd; ^ K/B[8
nThreadID = id; ]J~5{srq:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #Qkl| h
} ]SK(cfA`
l*h6JgU
|>VHV} 4)<
public void run() W0R6<- 1
{ "|f;
while(nStartPos < nEndPos && !bStop) B} &C h
{ 9~a_^m/
JG4Tb{F=
-O2QzzE&
try{ )M1.>?b
URL url = new URL(sURL); MTr _8tI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fz<Y9h=
httpConnection.setRequestProperty("User-Agent","NetFox"); !zD| @sX{
String sProperty = "bytes="+nStartPos+"-"; <&:3|2p
httpConnection.setRequestProperty("RANGE",sProperty); #LF_*a0v
Utility.log(sProperty); d`^j\b>5(
S7-?&[oeJ
!m78/[LW
InputStream input = httpConnection.getInputStream(); x!S8'
//logResponseHead(httpConnection); x'}{^'}/
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; <3w ,r
byte[] b = new byte[1024]; KPKby?qQ^
int nRead; x%LWcT/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2f F)I&
{ ;0@"1`
nStartPos += fileAccessI.write(b,0,nRead); \}Hk`n)Aq
//if(nThreadID == 1) 3&_(D)+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z^~fVl
} :s*&_y
=w,%W^"E
T<P4+#JK
Utility.log("Thread " + nThreadID + " is over!"); _M{m6k(h
bDownOver = true; GMd81@7
//nPos = fileAccessI.write (b,0,nRead); ?zxKk(J
} 0p![&O
catch(Exception e){e.printStackTrace ();} N/]TZu~k z
} .] 5&\
} ,X+071.(
%xL3=4\
lkBab$S)
//打印回应的头信息 61CNEzQ
public void logResponseHead(HttpURLConnection con) :'#BU:
{ PE+N5n2Tl
for(int i=1;;i++) 9NKZE?5P|D
{ RDk{;VED{
String header=con.getHeaderFieldKey(i); 3)I v8mA
if(header!=null) >(*jL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lAV6z%MmM
Utility.log(header+" : "+con.getHeaderField(header)); l0Y(9(M@
else vBq2JJAl
break; [96|xe\s
} O]i}r`E8,
} QR<IHE{~8
IN),Lu0K
w~Es,@
public void splitterStop() amgYr$)m
{ P !6r`d
bStop = true; mLKwk6I
} H|==i2V{
(~,Q-w"
{H"xC~.
} G$Z8k,g+<7
%;9wToyK>
GXJJOy1"!
/* F6YMcdU
**FileAccess.java )=ZWn,ZB
*//文件访问(定位，写) <eb>/ D
package NetFox; b[VP"KZ?
import java.io.*; 99H&#!~bSS
B4_0+K H
(N0G[(>
public class FileAccessI implements Serializable{ FtT+Q$q=
v6TH-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EivZI<<a
RandomAccessFile oSavedFile; <wc=SMmO
long nPos; L0_R2EA
#Z(8 vA^@
YM/^-[k3
public FileAccessI() throws IOException r4D6g>)h1q
{ ZOyq{w!2
this("",0); [uW{Ap~2
} 0B>{31)
#*1\h=bzmW
0=yKE J
public FileAccessI(String sName,long nPos) throws IOException KKl8tI\u~
{ ;Rt?&&W
oSavedFile = new RandomAccessFile(sName,"rw"); 7YkxIzE
this.nPos = nPos; dEJ>8e8
oSavedFile.seek(nPos); J'.U+XU
} )9l5gZX'I
^+Ec}+ Q
=0MW+-
public synchronized int write(byte[] b,int nStart,int nLen) (]0ZxWF
{ BoHMz/DB
int n = -1; CXb)k.L
try{ a$l/N{<.
oSavedFile.write(b,nStart,nLen); $@7S+'Q3
n = nLen; Pv+[N{
} Zii<jZ.)<
catch(IOException e) N?ky2wG
{ -{-w5_B$
e.printStackTrace (); 1wi{lJaz
} /`Yp]l
CT6a
y8D'V)B
return n; oost}%WxN
} h7wm xa;
qWfG@hn
Wm7Dy7#l
} #7/_Usso
8~u#?xs6
XA-DJ
/* O)kC[e4
**SiteInfoBean.java n[[rI0]g
*/ ?R&,1~h
package NetFox; "nf.kj:>
[2a*TI
Sdy\s5
public class SiteInfoBean { YrS%Yvhj0
7^A;.x
>c|u|^3zt
private String sSiteURL; //Site's URL :CNHN2 J
private String sFilePath; //Saved File's Path [u[F6Wst
private String sFileName; //Saved File's Name &s>HiL>f
private int nSplitter; //Count of Splited Downloading File D ?1$I0=
Q *![u5#
S>Z V8
public SiteInfoBean() y<.0+YL-e+
{//nSplitter的缺省值为5 NX4!G>v
//default value of nSplitter is 5 T9osueh4
this("","","",5); q.`+d[Q2
} ]!E|5=q
l4I@6@
;H9d.D8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TyY[8J|
{ Yc/Nz(m
sSiteURL= sURL; }xJ9EE*G/
sFilePath = sPath; iov55jT~l@
sFileName = sName; %=xR$<D
this.nSplitter = nSpiltter; {0+gPTp
TL ;2,@H`
k6_RJ8I
} J@54B
I83ZN]
E)DdiB'Rh
public String getSSiteURL() <03@cs
{ ~@S5*(&8
return sSiteURL; -9Wx;u4]o
} rR@ t5
]&`_5pS
kz\ D-b
public void setSSiteURL(String value) +|Z1U$0g
{ O;h]
sSiteURL = value; `VCU`Y
} )sWdN(E3
lG;RfDI-
^} P|L
public String getSFilePath() eN fo8xUG
{ al$G OMi
return sFilePath; ))^rk6
} <*E{zr&
T>2)YOx
=|O`al
public void setSFilePath(String value) Mt(wy%{zK
{ ("<3w2Vlh
sFilePath = value; P/5bNK!
} ]S<y,d-
|q"WJQ
xwhH_[
public String getSFileName() -} \g[|
{ 6*u#^">,<
return sFileName; {|= 8wB
} 'L4@|c~x
mE^mQ [Dk
t$^1A1Ef
public void setSFileName(String value) ;A7HEx
{ <yz)iCU?
sFileName = value; OQ;'Xo
} `VX]vumG
~n9BN'@x
4vKp341B
public int getNSplitter() E5qh]z(
{ QNj hA'[T
return nSplitter; b3N>RPsHS
} zim]3%b*A;
25]Mi2_
9r=@S
public void setNSplitter(int nCount) hn\<'|n
{ n=!]!'h\:
nSplitter = nCount; NPy{ =#k4
} 1^ZQXUzl%i
} &0Yv*,4]
T8+A`z=tSb
)/kkvI()l
/* Njsz=
**Utility.java <cm,U)j2
*/ ]o`qI#{R~R
package NetFox; d~@&*1}
ZLw7-H6Fh
n*~=O'
public class Utility { m"*j J.MX
!N:!x[5
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public Utility() "Opk:;.
{ x LR 2H>B}
\o3)\ e]o
Mqc"
} H1X38
7.)e4
//线程睡眠 SRs1t6&y=
public static void sleep(int nSecond) .O!JI"?
{ o&}!bq]
try{ _V\rs{ 5
Thread.sleep(nSecond); ))f%3_H
} ^]:w5\DG
catch(Exception e) 4TcKs}z
{ ZYDLl8
e.printStackTrace (); #G2~#\
} A*#.7Np!"
} ]G.ttfC
P(pw$ q$S
//日志 &5>R>rnB
public static void log(String sMsg) 5ZeE& vG2
{ [r,a0s
System.err.println(sMsg); Gq%q x4
} 1|$V
QCB2&lN\&L
&|>CW:)&1"
public static void log(int sMsg) 6UK{0\0
{ Y+5nn
System.err.println(sMsg); *ue- x!"c
} /RD@ [ 8
} .?{rd3[ec
y)iT-$bQ
wG;#L7%
/* V5w00s5?%
**TestMethod.java c'M#va
*/ (B|4wR\
package NetFox; w#]> Nf
i#Tm] ++
umPd+5i
public class TestMethod { a@(4X/|
7<{g+Q~7*
9gNQ,c \gT
public TestMethod() Bk,:a,
{ ///xx/weblogic60b2_win.exe 2ghTAsUx9
try{ ]WlE9z7:8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %:i; eUKR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J2A+x\{<
SiteFileFetch fileFetch = new SiteFileFetch(bean); &+V6mH9m@
fileFetch.start(); "|P8L| @*
} wdS4iQD
catch(Exception e){e.printStackTrace ();} w`_cmI
MmUtBT
ZH'- >/
} n^F:p*)Q%
ZlaU+Y(_[
pxm{?eBz
public static void main(String[] args) R@*mMWW,
{ .m--#r
new TestMethod(); &!/E&e$_
} %eJolztKZ
} <1")JDW
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