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)); oA%[x
} j'x{j %U
for(int i=0;i<nEndPos.length-1;i++) Y/(-mcR
{ 1*CWHs
nEndPos = nStartPos[i+1]; ,LO-!\L
} B9-[wg#0G
nEndPos[nEndPos.length-1] = nFileLength; ][1u:V/ U
} ]*U')
} r,KK%B
-y.AJ~T
~{Bi{aK2
//启动子线程 [![(h %
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A\.*+k/B
for(int i=0;i<nStartPos.length;i++) !c($C
{ f~9Y1|6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $3B?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O3: dOL/C
nStartPos,nEndPos,i); VrxH6Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Acv{XnB
fileSplitterFetch.start(); elB 8
} lHqx}n@e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~]M"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VAt9JE;#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H12@12v
nEndPos = " + nFileLength); 8E[`H
// fileSplitterFetch[nPos.length-1].start(); 1z:N$O_v
x&vD,|V!
LL [>Uu?Y
//等待子线程结束 Uroj%xN
//int count = 0; aB'@8[]z
//是否结束while循环 (=/;rJ`q
boolean breakWhile = false; MT0{hsuK9
R*m"'|U
IBh~(6
while(!bStop) R!G7;m'N1
{ Yk?q7xuT
write_nPos(); G'f"w5%qZv
Utility.sleep(500); $SR]7GZ
breakWhile = true; N2e<Y_T
%T\x~)
n<*]`do,w
for(int i=0;i<nStartPos.length;i++) %Ege^4PE
{ J7vpCw2ni
if(!fileSplitterFetch.bDownOver) [+z:^a1?V
{ eov-"SJB
breakWhile = false; .YF-t`{
break; #+k[[; 0
} yFsXI0I[p
} pnJT]?},
if(breakWhile) qTF>!o#\:
break; 3PffQ,c[~
Z+(V \
xltu g##
//count++; FG:BRS<m~
//if(count>4) ppKCY4
// siteStop(); 1+($"$ZC&B
} Beg5[4@
d2sq]Q
)xy6R]_b
System.err.println("文件下载结束！"); |vzWSm
} pN_!&#|+$
catch(Exception e){e.printStackTrace ();} [CX?Tt
} & jvG]>CS'
Sw'?$j^3
lJ#>Y5Qg
//获得文件长度 RC%r7K f
public long getFileSize() U$uO%:4%
{ d?Cl04
int nFileLength = -1; /|AuI qW
try{ 'qE
URL url = new URL(siteInfoBean.getSSiteURL()); 0B/a$NC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 06 s3 b
httpConnection.setRequestProperty("User-Agent","NetFox"); g<%-n,
&y\2:IyA
#"-^;Z
int responseCode=httpConnection.getResponseCode(); yfQE8v+
if(responseCode>=400) eCD,[At/
{ HC,@tfS
processErrorCode(responseCode); f@L{*Upj+
return -2; //-2 represent access is error b%j:-^0V
} BwD1}1jp
^/vWK\-
3=7h+ZgB
String sHeader; krc!BK`V
^#se4qQ
-74T C
for(int i=1;;i++) >/bK?yT<
{ _B FX5ifK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K9'*q3z
//Utility.log(in.readLine()); 8-YrmP2k
sHeader=httpConnection.getHeaderFieldKey(i); WEAXqDjM
if(sHeader!=null) S\gP=.G
{ *wcoDQ b;
if(sHeader.equals("Content-Length")) 7g+]
{ %tQ{Hf~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Qe.kNdT+_
break; ^?[<!VBI
} _\PoZ|G4y
} E,yK` mPp^
else VTfaZ/e.
break; REBDr;tv
} j],.`Y
} tta0sJ8i
catch(IOException e){e.printStackTrace ();} ] Nipo'N;
catch(Exception e){e.printStackTrace ();} aZ`agsofk
;@~*z4U
:Xh`.*{EX
Utility.log(nFileLength); @$Kq<P
,8nZzVo
,s&~U<Z
return nFileLength; SJ^?D8
} iDc|9"|Tf3
?Zp!AV
1[9j`~[([
//保存下载信息（文件指针位置） Nj&%xe>].
private void write_nPos() ^|(4j_.(e
{ <W') ~o}
try{ ;XQ lj?:
output = new DataOutputStream(new FileOutputStream(tmpFile)); X>8?p'*
output.writeInt(nStartPos.length); fhx:EZ:~
for(int i=0;i<nStartPos.length;i++) pu*u[n
{ 8w?\_P7QA
// output.writeLong(nPos); ;I71_>m
output.writeLong(fileSplitterFetch.nStartPos); g@VndAp
output.writeLong(fileSplitterFetch.nEndPos); _rdj,F8
} D#}Yx]Q1
output.close(); Am0C|(#Xm
} m@yVG|eP#
catch(IOException e){e.printStackTrace ();} _k.bGYldk
catch(Exception e){e.printStackTrace ();} Jd"s~n<>K
} N4|q2Jvj6
,!u@:UBT
i9k]Q(o
//读取保存的下载信息（文件指针位置） y$V)^-U>fw
private void read_nPos() U*"cf>dB(
{ vD9D:vK
try{ 05I39/T%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2BA9T nxC
int nCount = input.readInt(); - :z5m+
nStartPos = new long[nCount]; 4@iJ|l
nEndPos = new long[nCount]; ruA+1-<f
for(int i=0;i<nStartPos.length;i++) 13_~)V
{ bRz^=
nStartPos = input.readLong(); RXS|-_$
nEndPos = input.readLong(); *oX]=u&
} pQ(eF0KG
input.close(); Ss! 3{VW
} 5=h'!|iY
catch(IOException e){e.printStackTrace ();} 1$D`Z/N"A
catch(Exception e){e.printStackTrace ();} e0WSHg=6@
} |aAWWd5
=C>`}%XT}
|abst&yp
private void processErrorCode(int nErrorCode) U3+_'"
{ <i\zfa'6
System.err.println("Error Code : " + nErrorCode); 'Mx K}9
} 3]OP9!\6
D6)Cjc>a
S*m`'
//停止文件下载 ^~<Rzq!
public void siteStop() RzJ}CT
{ p6y0W`U
bStop = true; &DQ4=/Z
for(int i=0;i<nStartPos.length;i++) pkN:D+gS
fileSplitterFetch.splitterStop(); skDk/-*R
v&b.Q:h*'
VFmg"^k5
} 2*q: ^
} 3 [)s;e
//负责部分文件的抓取 _Z66[T+M
**FileSplitterFetch.java KD"&_PX
*/ 26#Jhb E+
package NetFox; /.kna4k
nHA`B.:B
}8F$& AFt
import java.io.*; tGO[A#9a
import java.net.*; ^A"lkV7
K l0tyeT
J6( RlHS;
public class FileSplitterFetch extends Thread { +>WC^s
qz=#;&ZU
1'v!9
String sURL; //File URL keQXJ0
long nStartPos; //File Snippet Start Position m$E^u[
long nEndPos; //File Snippet End Position U|Z>SE<k
int nThreadID; //Thread's ID ')u5l
boolean bDownOver = false; //Downing is over XL7;^AE^Wl
boolean bStop = false; //Stop identical 9oz(=R
FileAccessI fileAccessI = null; //File Access interface ,D@;i
f5yux}A{
W93JY0Ls9|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &I}T<v{f
{ Q),3&4pM
this.sURL = sURL; [71#@^ye
this.nStartPos = nStart; `zzKD2y
this.nEndPos = nEnd; *L;pcg8{
nThreadID = id; !V]MLA`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MB8SB
} i2FD1*=/?
q1TW?\pjb:
:e&n.i^
public void run() 1] %W\RHxo
{ @k+%y'Y?
while(nStartPos < nEndPos && !bStop) K(Q]&&<
{ X<Th{kM2
*TM;trfz
t8DL9RW'
try{ hEv=T'*,K)
URL url = new URL(sURL); i+)}aA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &}nBenYp
httpConnection.setRequestProperty("User-Agent","NetFox"); <g3du~
String sProperty = "bytes="+nStartPos+"-"; %kK ][2e
httpConnection.setRequestProperty("RANGE",sProperty); ws>WA{]gq
Utility.log(sProperty); $"sq4@N
~MhgAC
crJ7pe9
InputStream input = httpConnection.getInputStream(); JQ"`9RNb
//logResponseHead(httpConnection); hgweNRTh!
"?.'{,Q
7b&JX'`Mb
byte[] b = new byte[1024]; 't|Un G
int nRead; TvunjTpaj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ([,vX"4
{ MX!u$ei
nStartPos += fileAccessI.write(b,0,nRead); %XP_\lu]
//if(nThreadID == 1) sK`~Csb iB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \~@[QGKN
} }W:*aU
9Z,*h-o
+Lm3vj_N
Utility.log("Thread " + nThreadID + " is over!"); 1B)Y;hg6&
bDownOver = true; Iv$:`7|crX
//nPos = fileAccessI.write (b,0,nRead); bZNIxkc[Dh
} ;wij}y-6
catch(Exception e){e.printStackTrace ();} ,vPe}OKj
} _tWJXv~;
} DtzA$|Q}
hLb;5u&!kW
(jU/Wj!q
//打印回应的头信息 \Fj5v$J-
public void logResponseHead(HttpURLConnection con) -VS9`7k
{ C#MFpT
for(int i=1;;i++) M{`/f@z(
{ :s'o~
String header=con.getHeaderFieldKey(i); -O|&c9W.O
if(header!=null) -DTB6}kw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /> ^@ O
Utility.log(header+" : "+con.getHeaderField(header)); Yim{U:F
else ;i<$7MR.e
break; ic%?uWN
} .6> hD1'
} 3B@y &a#&
*#3*;dya]
&|v{#,ymeb
public void splitterStop() PX;Vo~6
{ 3/X-Cr+d
bStop = true; `J72+RA
} wgCvD
)O,wRd>5
CF]i}xpWV
} =%!e(N'p
N>+P WE$
S8 :"<B)
/* &J8Z@^
**FileAccess.java hf;S]8|F
*//文件访问(定位，写) Q*]$)D3n
package NetFox; 6}ce1|mkg/
import java.io.*; 1hl]W+9
B\\6#
!7}IqSs
public class FileAccessI implements Serializable{ /-h6`@[
z5x _fAT(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U1OFDXHG
RandomAccessFile oSavedFile; c\At0.QCA
long nPos; AgIazv1
^NXcLEaP*<
Rv=DI&K%n
public FileAccessI() throws IOException ~@{w\%(AK]
{ <"W?<VjO
this("",0); [+;qWfs B
} {@?G 9UypA
Ck: 9gn
X*i/A<Y`=
public FileAccessI(String sName,long nPos) throws IOException / /'Tck
{ :z]}ZZ
oSavedFile = new RandomAccessFile(sName,"rw"); ?AEd(_a!q
this.nPos = nPos; -;^;2#](g
oSavedFile.seek(nPos); nSS>\$
} P` #QGZ>
[r(Qs|
r#A_RZ2~@
public synchronized int write(byte[] b,int nStart,int nLen) 7KU~(?|:h
{ z"lqrSJ:
int n = -1; /RGNAHtIi
try{ @}WNKS&m
oSavedFile.write(b,nStart,nLen); blGf!4H
n = nLen; *I0Tbc O
} ] /+D^6
catch(IOException e) %?bcT[|3
{ u_PuqRcs
e.printStackTrace (); &-M]xo^
} f|U0s
baee?6
+iy7e6P
return n; Zmf'{tT5
} $$hv`HE^l
Ur^j$B}
@9Q2$
} 'B_\TU0 O
qos`!=g?
1~J5uB4
/* 5!Bktgk.
**SiteInfoBean.java IS BV%^la|
*/ MM?`voj~`p
package NetFox; Rs*vm
6-B 9na
m#f{]+6U
public class SiteInfoBean { c8{]]
f6!D L<
3NIUW!gr
private String sSiteURL; //Site's URL Tv5g`/e=Ej
private String sFilePath; //Saved File's Path mf' ]O,
private String sFileName; //Saved File's Name dA_YL?or
private int nSplitter; //Count of Splited Downloading File @m~RtC-Q
?7jg(`Yh
aQ#qRkI
public SiteInfoBean() WA$JI@g
{//nSplitter的缺省值为5 >xu[q\:"
//default value of nSplitter is 5 fr[3:2g-_
this("","","",5); r[_4Lo@G
} "CQw/qZw
|Ps% M|8~
[mUBHYD7OI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N j4IQ<OV
{ ,Q/Ac{C
sSiteURL= sURL; W2Luz;(U
sFilePath = sPath; :B|Dr v
sFileName = sName; Lq (ZcEKo
this.nSplitter = nSpiltter; LZ U$
9b;A1gu
QvLZg
} Sm-wH^~KA
FJNF%a)x2I
5,pSg
public String getSSiteURL() %zeATM[`
{ C`V)VJM
return sSiteURL; T*~H m
} %UZVb V
C+{l7QT$t
'9?;"=6(
public void setSSiteURL(String value) EE=3
{ ZH,4oF
sSiteURL = value; w$|l{VI
} dQb.BOI)h
N]N4^A'
Nt:9MG>1
public String getSFilePath() LfLFu9#:w
{ 6rN(_Oi-
return sFilePath; B[5r|d'
} xJZ@DR,#
X|DO~{-au
x9W(cKB'S
public void setSFilePath(String value) /mM2M-
{ O 5Nb
sFilePath = value; }(XdB:C8
} kJQ#Wz|z]
q<#>HjC
vuQ%dDxI
public String getSFileName() -e u]:4
{ ]@^coj[
return sFileName; oU6y4yO
} r\`+R"
oslJC$cy'
a`(a)9i
public void setSFileName(String value) =PHIpFIuk
{ 7piuLq+
sFileName = value; m~hoE8C$
} s;flzp8
6\jf|:h
}MbH3ufC
public int getNSplitter() Q,h7Sk*
{ C1EtoOv K
return nSplitter; 76cG90!Z
} k0-G$|QgIp
cLY c6
qU6nJi+-I
public void setNSplitter(int nCount) US [dkbKo
{ Gfp1mev
nSplitter = nCount; +;}#B~:
} L I>(RMv
} )~6zYJ2
W5L iXM
7Q w|!
/* 6x)$Dl
**Utility.java !R-z%
*/ s@hRqGd:
package NetFox; D}C,![
'_k+WH&
:!a2]-D}
public class Utility { '})0!g<Y
P|tNL}2`;
`+:.L>5([
public Utility() wa=uUM_4u^
{ 3@Z#.FV~C[
S& #U!#@
(+<1*5BEkT
} hN2:d1f0
wkqX^i7ls
//线程睡眠 Cv ejb+
public static void sleep(int nSecond) ?Iyo9&1&
{ )}vNOE?X~
try{ ps .]N
Thread.sleep(nSecond); 'J&f%kx"
} v[plT2"s
catch(Exception e) h7*W*Bd
{ `Q3s4VEC
e.printStackTrace (); l!}:|N Yh!
} -<v~snq'
} `@[c8j7
4wd&55=2
//日志 2&c9q5.b
public static void log(String sMsg) ZOXIT(mg
{ 'Jf^`ZT}
System.err.println(sMsg); !zj0/QG\
} /xGmg`g<#
0;4t&v7
@_:]J1jw7
public static void log(int sMsg) ~_s?k3cd
{ 'TH15r@
System.err.println(sMsg); 6hZ@;Q=b
} [gy*`@w
} T,xPSN2A*
*_E|@y
cLPkK3O\=
/* K7Rpr.p
**TestMethod.java \Y6WSj?E
*/ bY}eUL2i4
package NetFox; 'XY`(3q
YEkh3FrbwH
.<tquswg
public class TestMethod { {-|{xBd
SS`qJZ|w
F:y[@Yn
public TestMethod() F":r4`5D"K
{ ///xx/weblogic60b2_win.exe `qd+f{Q
try{ b=~i)`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D+_oVob\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~4P%%b0,o
SiteFileFetch fileFetch = new SiteFileFetch(bean); K=!Bh*
fileFetch.start(); fwK}/0%
} (b'B%rFO
catch(Exception e){e.printStackTrace ();} V $z} K
=@k%&* Y?
upj]6f"(
} d*)CT?d&
yQ#:J9HMJ
={LMdC~5X
public static void main(String[] args) yG Wnod'
{ ` PYJ^I0
new TestMethod(); Z2im@c67{
} TuW%zF/
} J|'7_0OAx
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