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)); .XpuD,^;@
} Xg.Lo2s
for(int i=0;i<nEndPos.length-1;i++) W. d',4)
{ sssw(F
nEndPos = nStartPos[i+1]; t<Sa;[+
} z*HM_u
nEndPos[nEndPos.length-1] = nFileLength; )4fQ~)
} (tO4UI5!
} dr#%~I
T=NLBJ
y ;mk]
//启动子线程 5[g&0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \<I&utn
for(int i=0;i<nStartPos.length;i++) /y1+aTiJ
{ L%[>z'Zp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ="G2I\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [<r.M<3
nStartPos,nEndPos,i); b4:{PD~Mh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K1YxF
fileSplitterFetch.start(); jNbVp{%/S}
} jhRr!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _G)A$6weU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;Q3[} ]su
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b1^wK"#
nEndPos = " + nFileLength); L=54uCv Q
// fileSplitterFetch[nPos.length-1].start(); m|JA}&A
o w(9dB&E
UZsvYy?
//等待子线程结束 }r18Y6
//int count = 0; IqlCl>_j
//是否结束while循环 |FFz $'8)
boolean breakWhile = false; BN(=LQ2["
1z|bQ,5
7Z9'Y?[m
while(!bStop) yC ?p,Ci,
{ G>?kskm
write_nPos(); V~jp
Utility.sleep(500); C-ORI}o
breakWhile = true; dU_;2d$
oFp1QrI3k8
+hKU]DP2;
for(int i=0;i<nStartPos.length;i++) l4mRNYv)z
{ W*iTg%a\k
if(!fileSplitterFetch.bDownOver) f>xi(0
{ ;HYEJ3
breakWhile = false; IAbQgBvUD
break; ta5_k&3N
} NHUJ:j@
} 1mHS -oI9J
if(breakWhile) +<$nZ=,hsy
break; S/*\j7cj
@gqZiFM)
Rkg)yme!N
//count++; An}RD73!w
//if(count>4) C ]B P}MY<
// siteStop(); DXj>u9*%
} yQ^,>eh
QiA}0q3]0
H9'psv
System.err.println("文件下载结束！"); &tbAXU5$
} 6n]jx:CZ,
catch(Exception e){e.printStackTrace ();} 3O4,LXdA
} 9:g]DIL
ho6hjhS|u
QSzht$8
//获得文件长度 <!G\%C
public long getFileSize() gP|-A`y
{ gT=pO`a
int nFileLength = -1; )sQ/$gJ
try{ RIUJX{?
URL url = new URL(siteInfoBean.getSSiteURL()); myVa5m!7Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {d#sZT
httpConnection.setRequestProperty("User-Agent","NetFox"); I%:?f{\
4dN <B U
T)<^S(57
int responseCode=httpConnection.getResponseCode(); 96;5
if(responseCode>=400) :!cK?H$+
{ A[@koLCL
processErrorCode(responseCode); fp(zd;BSQ
return -2; //-2 represent access is error $;(@0UDE
} ab9ecZ
%H{;wVjK
g/68& M
String sHeader; gREk,4DAv
s5G`?/
g-!
for(int i=1;;i++) *@^@7`W
{ .>r3ZwrE'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V=&M\58
//Utility.log(in.readLine()); _U LzA
sHeader=httpConnection.getHeaderFieldKey(i); [f {qb\
if(sHeader!=null) X}]A_G
{ 2[=3-1c
if(sHeader.equals("Content-Length")) "~.4z,ha
{ fUCjC*#1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S8kzAT
break; $"( 15U
} *pD|N
} $8(QBZq
else %2b^t*CQ
break; )l! /7WKY
} u^MRKLn
} :_xfi9L~W0
catch(IOException e){e.printStackTrace ();} 7f k)a
catch(Exception e){e.printStackTrace ();} mrsmul{
}pf|GdL
pl[@U<8aw
Utility.log(nFileLength); F =*4]O
31 <0Nw;l
J,?F+Qji&=
return nFileLength; LauGT* z!
} 1MO-60
2<!IYEyT
){)-}M
//保存下载信息（文件指针位置） YL!{oHs4
private void write_nPos() ' =5B
{ Id`V`|q
try{ Nr]Fh
output = new DataOutputStream(new FileOutputStream(tmpFile)); $kN=45SR
output.writeInt(nStartPos.length); oj{CNa
for(int i=0;i<nStartPos.length;i++) \1<|X].jNY
{ !"yr;t>|Zb
// output.writeLong(nPos); ia_@fQ
output.writeLong(fileSplitterFetch.nStartPos); ,W[J@4.
output.writeLong(fileSplitterFetch.nEndPos); ?Be}{Qqlg
} aaKf4}
output.close(); uxDM #
} A/:_uqm4
catch(IOException e){e.printStackTrace ();} ^$% Sg//
catch(Exception e){e.printStackTrace ();} (y6}xOa(
} :Cx|(+T
_[E+D0A
1|w@f&W"
//读取保存的下载信息（文件指针位置） ORF:~5[YS`
private void read_nPos() +ansN~3
{ -n[(0n3c
try{ } )Lz%Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7$g$p&,VX
int nCount = input.readInt(); ,YvOk|@R
nStartPos = new long[nCount]; /i27F2NQm
nEndPos = new long[nCount]; q1eMK'1
for(int i=0;i<nStartPos.length;i++) J]Z~.f="
{ T\$i=,_$
nStartPos = input.readLong(); <},JWV3
nEndPos = input.readLong(); [mjie1j/<
} #|,cy,v4
input.close(); |LbAW/9a
} vC@^B)5gb
catch(IOException e){e.printStackTrace ();} *{+{h;p
catch(Exception e){e.printStackTrace ();} #O;JV}y
} E X'PRNB,
a9p:k ]{
bFajK;
private void processErrorCode(int nErrorCode) ILAn2W
{ qF`6l(
System.err.println("Error Code : " + nErrorCode); YI7M%B9Lj
} Mth:V45G|
ti%RE:*
_h#I}uJ~
//停止文件下载 TvDC4tm-:
public void siteStop() 3Ji$igL
{ g6lWc@]F
bStop = true; AnX<\7bc}
for(int i=0;i<nStartPos.length;i++) QM3DB
fileSplitterFetch.splitterStop(); z#o''
hchG\i
m#8[")a$"
} vaP`'
} X|Y(*$?D7
//负责部分文件的抓取 Ky%lu^
**FileSplitterFetch.java 9-{=m+|b
*/ ^s7!F.OC
package NetFox; ,I5SAd|dX
wz69Yw7
3Y2~HuM
import java.io.*; <C(o0u&/
import java.net.*; OHpV%8`
&5R|{',(Y
'n,V*9
public class FileSplitterFetch extends Thread { bz#]>RD
=iKl<CqI$E
cXqYO|3/M
String sURL; //File URL 9!uiQ
long nStartPos; //File Snippet Start Position kq5X<'MM9N
long nEndPos; //File Snippet End Position P* `*^r3
int nThreadID; //Thread's ID W +ER'lX
boolean bDownOver = false; //Downing is over jmkOu5@
boolean bStop = false; //Stop identical dV'EiNpf
FileAccessI fileAccessI = null; //File Access interface *QiQ,~Ep
rfEWh Vy(}
-GCo`PR?b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException / 'qoKof
{ 9)'f)60^
this.sURL = sURL; Q7XOO3<):
this.nStartPos = nStart; wTa u.Bo
this.nEndPos = nEnd; ]n|Jc_Y
nThreadID = id; w90YlWS#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J>}J~[ap\J
} \/Mx|7<
^ UmYW
z.SC^/\o|
public void run() 7:<w)Al!
{ + tMf&BZ
while(nStartPos < nEndPos && !bStop) ?![[la+f
{ :NF4[c
,?|$DY+=
OA[e}Vn
try{ ]c7X~y
URL url = new URL(sURL); MqAi}z%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vW=L{8zu
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Ckx.m&
String sProperty = "bytes="+nStartPos+"-"; HTOr
httpConnection.setRequestProperty("RANGE",sProperty); m<-ShRr*b
Utility.log(sProperty); I} jgz
3@gsKtA&H4
Ck Nl;g l
InputStream input = httpConnection.getInputStream(); }<0N)dpT
//logResponseHead(httpConnection); Xv-p7$?f
m|qktLx
;Nj9,Va(t
byte[] b = new byte[1024]; aE`d[dSG
int nRead; c[,h|~K/_?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6UeYZ g
{ R{H[< s+n
nStartPos += fileAccessI.write(b,0,nRead); e(?w h
//if(nThreadID == 1) O1z]d3x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'f-r 6'_ZX
} FzJ7 OE|
~Ba=nn8Cq
W}CM;~*L
Utility.log("Thread " + nThreadID + " is over!"); uX6yhaOp|
bDownOver = true; x)~i`$
//nPos = fileAccessI.write (b,0,nRead); {p84fR1P
} tR|dnC4U
catch(Exception e){e.printStackTrace ();} a]T:wUYG'
} lhGJ/By- -
} v4n< G-
Vb(b3
kUf i
//打印回应的头信息 (aa2uctTn
public void logResponseHead(HttpURLConnection con) {rUg,y{v
{ eluN~T:W
for(int i=1;;i++) @&ZQDi
{ yWi-ic [n
String header=con.getHeaderFieldKey(i); DW. w=L|5R
if(header!=null) yfZNL?2x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q<dG}aj
Utility.log(header+" : "+con.getHeaderField(header)); ?;ok9Y
else $eYL|?P50h
break; <e2l@@#oy
} 1 ~zjsi
} lT|Gkm<G
ITn%
K oJ=0jM#
public void splitterStop() zw>L0gC
{ )XN_|zCk
bStop = true; 4E39]vb
} :RIz6Tz
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p{g4`o
} ??,[-Oi
}Kp!,
f+h\RE=BGt
/* ,CfslhO{j
**FileAccess.java -]Z7^
*//文件访问(定位，写) Q/+`9z+c
package NetFox; Dr3_MWJ+
import java.io.*; ,vR?iNd:q[
K~TwyB-h
e&}W#
public class FileAccessI implements Serializable{ IfK~~XYG
Lx0nLJ\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cS;3,#$
RandomAccessFile oSavedFile; SVe]2ONd
long nPos; 9TW[;P2> )
D=0YLQ*rP
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public FileAccessI() throws IOException ]`/>hH>+~9
{ xb,XI/
this("",0); k]~o=MLmj
} } oPO`
K^u,B3
V`Cyx^P
public FileAccessI(String sName,long nPos) throws IOException tbFAVGcAM
{ iW5cEI%tb
oSavedFile = new RandomAccessFile(sName,"rw"); sQJ\{'g
this.nPos = nPos; ]r Uj<[O
oSavedFile.seek(nPos); YOl$sgg}
} 0:$}~T9T
t'n@yX_
+Nt4R:N
public synchronized int write(byte[] b,int nStart,int nLen) w% %q/![uy
{ `6Bx8CZ'I
int n = -1; x4MmBVqp
try{ 5h5izA'0'
oSavedFile.write(b,nStart,nLen); v e&d"8+]
n = nLen; 7>N~l
} |P >"a`
catch(IOException e) ,md_eGF
{ fiGTI}=P
e.printStackTrace (); UA>=# $
} u]yy%@U1
G4* LO
m\&|#yq
return n; a-{|/ n%
} ingG
h `Lr5)B'
S!(3-{nC
} n'~==2
7he73
1m*)MZ)
/* F.[%0b E
**SiteInfoBean.java lLD#|T3
*/ \V? .^/
package NetFox; Q:-T'xk@
TnF~'RZYb
)DgXsT
public class SiteInfoBean { 1G>Ud6(3<
%'Cj~An
nu0pzq\6
private String sSiteURL; //Site's URL G+zhL6]F
private String sFilePath; //Saved File's Path )bUnk+_
private String sFileName; //Saved File's Name orGMzC2
private int nSplitter; //Count of Splited Downloading File /K:r4Kw
}Fe6L;^;
@{Rb]d?&F?
public SiteInfoBean() ZQ`8RF *v
{//nSplitter的缺省值为5 -xn-Af!v
//default value of nSplitter is 5 =:H-9
this("","","",5); b>ai"!
} 4agW<c#
dY8 H2;
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lw@Yn>eza
{ 3&hR#;,"X
sSiteURL= sURL; zp}7p~#k^
sFilePath = sPath; p<5]QV7st
sFileName = sName; Q((&Q?Vi
this.nSplitter = nSpiltter; %*D=ni#(sT
[D"6&
z|#*c5Y9w
} ?P kJG,~
k2}DBVu1
G6G Bqp6|
public String getSSiteURL() %e iV^>
{ @{/)k%U
return sSiteURL; "Z.6@ c7
} p{Lrv%-j
)z[C=
ha :l-<a
public void setSSiteURL(String value) =pL$*`]?
{ fn}E1w
sSiteURL = value; ~+Wx\:TT
} vjEDd`jYZ
K~L&Z?~|E
Z RVt2
public String getSFilePath() NI?O
{ f_~T
return sFilePath; ;hT3N UCA
} )D8op;Fn
UmR)L!QT8
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public void setSFilePath(String value) XGa8tI[:X
{ l.}PxZ
sFilePath = value; "~4V(
} 5rsz2;#p
ufXWK3~\
"Bd-h|J
public String getSFileName() 9g6$"',H
{ [ V.67_~
return sFileName; OyO<A3
} GfONm6A
Ao K9=F}
,DFN:uf=l
public void setSFileName(String value) J!C \R5\
{ @)pC3Vi^
sFileName = value; ,Fn;*
} - Jaee,P
M5I`i{Gw
'\bokwsP
public int getNSplitter() mERkC,$
{ Cy-p1s
return nSplitter; ZF>:m>
} U$y9f
G&oD;NY@/
m` 1dB%;?
public void setNSplitter(int nCount) z^9oaoTl
{ [N,+mX
nSplitter = nCount; 7$*E0
} bxa>:71
} :<g0Ho?e
_7!ZnJrR
P'KA-4!
/* h8/tKyr8(
**Utility.java 6u_i>z
*/ ^q-%#
package NetFox; DOWWG!mx
q0ktABB
gSFZ>v*6
public class Utility { 8F[];LF>
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DuC#tDP
public Utility() K~:SLCv E%
{ 4)iP%%JH
%pVsafV
"}()/
} qc(e3x
)>~jjR
//线程睡眠 3EYEd39E
public static void sleep(int nSecond) z</C)ObL
{ ?NA$<0
try{ P%R!\i
Thread.sleep(nSecond); ?s,oH
} @|A!?}
catch(Exception e) Sh#N5kgD
{ 1uw1(iL+
e.printStackTrace (); $}vk+.!*1
} i$kB6B#==
} WN]k+0#
6%V:Z
//日志 0(i3RPIj\
public static void log(String sMsg) _i>_Sn1"
{ l~$)>?ZD
System.err.println(sMsg); ;bwBd:Y
} nc1~5eo
<VZ43I
}[leUYi`
public static void log(int sMsg) {XU!p: x
{ l2;$qNAo
System.err.println(sMsg); b@J"b(
} ((gI OTV
} T.cTL.}
FWu:5fBZY
Sfe[z=7S
/* ;MeY@*"{
**TestMethod.java g#(+:^3'
*/ '/`O*KD]
package NetFox; @vq)Y2)r\
T;DKDga
XW aa`q
public class TestMethod { YWU@e[
UG\2wH_
@95p[
public TestMethod() J4eU6W+{
{ ///xx/weblogic60b2_win.exe KKpM=MZ
try{ * 1}dk`-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NrS+N;i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7=G6ao7
SiteFileFetch fileFetch = new SiteFileFetch(bean); |6^a[x3/U
fileFetch.start(); Xr^ 5Th\
} rhLhFN{h
catch(Exception e){e.printStackTrace ();} @(L}:]{@
25Ee+&&%
L:C/PnIV
} d"5_x]Z;
IZrcn
Ch{6=k bK
public static void main(String[] args) Lu^uY7 ?}
{ H, 3Bf
new TestMethod(); X.{xHD&_
} 2XL^A[?
} z:S:[X0
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