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)); OYy%aA}h
} &``;1/J*W
for(int i=0;i<nEndPos.length-1;i++) cKFzn+
{ ?sp
nEndPos = nStartPos[i+1]; *vUKh^="
} 0(:"q!h
nEndPos[nEndPos.length-1] = nFileLength; m{gt(n
} TQ>kmHWf/
} f}eZX
}|{yd03+
Uhb6{'+
//启动子线程 QfT&y &
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YG"P:d;s
for(int i=0;i<nStartPos.length;i++) pmIQD"
{ FeLWQn/aV6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }T4"#'`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ##1[/D(
nStartPos,nEndPos,i); r`B8Cik
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vk@u|6U'
fileSplitterFetch.start(); WR gAc%
} ,MuLu,$/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OHM.xw*?.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &{/ `Q,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d!e$BiC
nEndPos = " + nFileLength); .5KRi6
// fileSplitterFetch[nPos.length-1].start(); "%-HZw%X
|giK]Z
C03ehjT<
//等待子线程结束 @j5W4HU
//int count = 0; VU}UK$JN
//是否结束while循环 +Rxf~m(pV
boolean breakWhile = false; x_bS-B)%Y:
D3(|bSca
JU/K\S2%,
while(!bStop) $PHKI B(
{ Y@_ i32,r
write_nPos(); 4\dc
Utility.sleep(500); K(Zd-U
breakWhile = true; 8O("o7~"
HQ ^> ~
.+|G`*1<i
for(int i=0;i<nStartPos.length;i++) &6r".\;^
{ H_vOZ0
if(!fileSplitterFetch.bDownOver) p\b:uy6#
{ "xdXHuX
breakWhile = false; >77 /e@
break; [[oX$0Fp\!
} WTSY:kvcCY
} -Ufd+(
if(breakWhile) <y(>z*T;
break; (#X/sZQh
X -w#E3
3Ki`W!C
//count++; i1\xZ<|0
//if(count>4) |Tf}8e
// siteStop(); Yf7n0Etd,
} T"dX)~E;
+:mj]`=
Pm#B'N#*N|
System.err.println("文件下载结束！"); W>bhSKV%
} !+JSguy
catch(Exception e){e.printStackTrace ();} %* vYX0W"
} c^Rz?2x
^md7ezXL
(ZT*EFhb(
//获得文件长度 ol:,02E&
public long getFileSize() P\*-n"
{ ?dC[VYC\^
int nFileLength = -1; oT5?*3f
try{ ,BOB &u
URL url = new URL(siteInfoBean.getSSiteURL()); CZxQz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); no)Spo'
httpConnection.setRequestProperty("User-Agent","NetFox"); c{V0]A9VF
+\\*Iy'xK
Apa)qRJd
int responseCode=httpConnection.getResponseCode(); ()}O|JL:K
if(responseCode>=400) ;)u}`4~L
{ UVxE~801Y
processErrorCode(responseCode); Ajs<a(,6
return -2; //-2 represent access is error -TjYQ
} eLL>ThMyW
{KdC51"Nv
4/~8zvz&3
String sHeader; 2fFNJ
Q^b_+M
9Rb-QI
for(int i=1;;i++) !M)!
{ iG6 ^s62z7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^$`xUKp`pn
//Utility.log(in.readLine()); ;!Ojb
sHeader=httpConnection.getHeaderFieldKey(i); T,`'qZ>
if(sHeader!=null) B#B$w_z
{ J55K+
if(sHeader.equals("Content-Length")) zTAt% w5
{ Haaungb"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %*oz~,i
break; E)09M%fe
} F2AM/m^!q
} {ylc2 1
else J,4]du$
break; 9K Ih}Q@P
} pvDr&n9
} NA]7qb%%<
catch(IOException e){e.printStackTrace ();} [qIi_(%o
catch(Exception e){e.printStackTrace ();} ;]i&AAbj
V4l`Alr\L
[WRs1$5
Utility.log(nFileLength); DSizr4R
*;,=x<
)j',e$m
return nFileLength; i>7f9D7
} gTH1FR8$y
1AjsAi,7;2
l:z:tJ#(
//保存下载信息（文件指针位置） C ])Q#!D|
private void write_nPos() e ! 6SJ7xC
{ dY;^JPT
try{ `[jQn;
output = new DataOutputStream(new FileOutputStream(tmpFile)); $io-<Z#Q
output.writeInt(nStartPos.length); TEh]-x`
for(int i=0;i<nStartPos.length;i++) nAoGG0$5
{ \&&kUpI
// output.writeLong(nPos); {YcVeCq+N
output.writeLong(fileSplitterFetch.nStartPos); x98LOO
output.writeLong(fileSplitterFetch.nEndPos); ]^3_eHa^d
} OcQ_PE5\
output.close(); zb?wlfT
} I{_St8
catch(IOException e){e.printStackTrace ();} PxfeU2^{0
catch(Exception e){e.printStackTrace ();} lqF{Y<l
} o~NeS|a
7B"J x^
0`h[|FYV
//读取保存的下载信息（文件指针位置） nbMH:UY,J
private void read_nPos() Jk}L+Xvv
{ P qagep d
try{ +h9UV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _>dqz(8#
int nCount = input.readInt(); >tr_Ypfv,c
nStartPos = new long[nCount]; JAC W#'4hV
nEndPos = new long[nCount]; ]n _-
for(int i=0;i<nStartPos.length;i++) PUltn}M
{ #Vs/1y`()
nStartPos = input.readLong(); >BrxJw#M
nEndPos = input.readLong(); E&{*{u4
} `yP-,lA$
input.close(); s|pb0
} ~XsS00TL`G
catch(IOException e){e.printStackTrace ();} Gqk"%irZ
catch(Exception e){e.printStackTrace ();} HAf.LdnzS
} a_waLH/
}(ay(
U"%k4]:A
private void processErrorCode(int nErrorCode) pvI(hjMYPk
{ SjtGU47$!
System.err.println("Error Code : " + nErrorCode); Rb#Z'1D'G
} {;n?c$r
Ook3B
9`4h"9dO
//停止文件下载 >, 234ab=d
public void siteStop() )@]-bPnv
{ x3PeU_9
bStop = true; :`:<JA3,
for(int i=0;i<nStartPos.length;i++) R>/M>*C
fileSplitterFetch.splitterStop(); g"(N_sv?
7/PHg)&
a}i{b2B
} '8*gJ7]
} $#]?\psf
//负责部分文件的抓取 /nv1.c)k
**FileSplitterFetch.java reu[}k~
*/ [O"i!AQ
package NetFox; 2O<Sig=
)P|%=laE8
{)4Vv`n
import java.io.*; F#X\}MvEU
import java.net.*; K ANE"M
.Z%7+[
e&;c^Z
public class FileSplitterFetch extends Thread { EOtrrfT&
Pk8L-[&v
u%XFFt5
String sURL; //File URL @]3(l
long nStartPos; //File Snippet Start Position *uA?}XEfi
long nEndPos; //File Snippet End Position <e/O"6='Z
int nThreadID; //Thread's ID 4fzq C)
boolean bDownOver = false; //Downing is over xBgf)'W_Z
boolean bStop = false; //Stop identical y^;qT_)#
FileAccessI fileAccessI = null; //File Access interface T2Y`q'
R&ou4Y:DG
lmH!I)5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7c %@2
{ &sS k~:
this.sURL = sURL; OUI}jJw+
this.nStartPos = nStart; ry~3YYEMI0
this.nEndPos = nEnd; LTzf&TZbx5
nThreadID = id; ^ / f*5k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DOhXb
} !PUhdW
F<V zVEx
}{K)5k@
public void run() Wv=L_E_
{ Z]w_2- -
while(nStartPos < nEndPos && !bStop) I=(O,*+PQ
{ :6HMb^4
)&_{m K
Y] P}7GZ
try{ -\UzL:9>
URL url = new URL(sURL); yA%[u.{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~@'|R%jJ
httpConnection.setRequestProperty("User-Agent","NetFox"); JSGUl4N
String sProperty = "bytes="+nStartPos+"-"; De>pIN;B>
httpConnection.setRequestProperty("RANGE",sProperty); N..9N$+(
Utility.log(sProperty); ~RvU+D
e% 5!
l' "<
InputStream input = httpConnection.getInputStream(); Nz!AR$
//logResponseHead(httpConnection); _F@FcFG1Z*
,x{5,K.yWq
F6%rH$aS
byte[] b = new byte[1024]; ;A-Ef
int nRead; _^P>@ ^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5+ fS$Q
{ Cs]xs9
nStartPos += fileAccessI.write(b,0,nRead); []dRDe;#
//if(nThreadID == 1) QtN0|q{af
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3>L1}zyM]
} L {B#x@9tQ
L"}@>&6
KJ9~"v
Utility.log("Thread " + nThreadID + " is over!"); ?[m5|ty#
bDownOver = true; S?Eg
//nPos = fileAccessI.write (b,0,nRead); 8De `.!Gg
} o,aI<5"
catch(Exception e){e.printStackTrace ();} e;!<3b
} NoKYHN^*w
} i^QcW!X&
=A!I-@]q<
57[O)5u.+
//打印回应的头信息 JRodYXjE
public void logResponseHead(HttpURLConnection con) m|f|u3'z$
{ \[>Rt
for(int i=1;;i++) {|rwIRe
{ dDm<'30?*v
String header=con.getHeaderFieldKey(i); YDmFR,047
if(header!=null) 0hNc#x6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B"Fg`s+]U
Utility.log(header+" : "+con.getHeaderField(header)); -C8awtbC
else G 8NSBaZe
break; X;6X K$"
} _')KDy7
} 97Q!Rot
4e%SF|(Y'h
%"KBX~3+Kj
public void splitterStop() w^ DAu1
{ ~&yaIuW<
bStop = true; x1Si&0T0P<
} ]h|GaHiE
@NyCMe;]
[n:R]|^a
} E3gQ`+wNg?
`mWg$e,
9]7^/g*!
/* A$5!]+
**FileAccess.java -7pZRnv
*//文件访问(定位，写) l[.pI];T
package NetFox; !MGQ+bD6
import java.io.*; Y.}n,y|J}
"arbUX~d
I`y}Ky<q
public class FileAccessI implements Serializable{ FijzO
] xH `
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SgY>$gP9S
RandomAccessFile oSavedFile; JgxOxZS`@
long nPos; IGbQ L
J7l1-
ZM)a4h,kcm
public FileAccessI() throws IOException 0#yo\McZ
{ Y)a 7osML
this("",0); @|cas|U.r
} bF}~9WEa
`U;4O)`n
-bs~{
public FileAccessI(String sName,long nPos) throws IOException h\20
{ M&>Z[o
oSavedFile = new RandomAccessFile(sName,"rw"); |~Z+Xla
this.nPos = nPos; M"V?fn'
oSavedFile.seek(nPos); UCq+F96j
} w-\GrxlbX
|9(uiWf
a"ht\v}1
public synchronized int write(byte[] b,int nStart,int nLen) gx9H=c>/
{ dwmj*+
int n = -1; M VsIyP
try{ $Itehy
oSavedFile.write(b,nStart,nLen); my*/MC^O
n = nLen; k'S/nF A
} &PGU%"rN
catch(IOException e) g.,IQ4o
{ ,7/N=mz
e.printStackTrace (); M/#<=XhA
} EmH2 Dbw
yCmiW %L4
W/&cnp\
return n; p'_*>%4~
} tt`b+NOH>
]^.#d
jLZ~9FXF2
} \a}%/_M\
N]5-#
!rwv~9I
/* //AS44^IS
**SiteInfoBean.java #5'9T:8
*/ sYp@.?Tz
package NetFox; ya|7hz{
A3h[VnuG,
3g} ]nj:N
public class SiteInfoBean { :PjHsNp;^
*%Q!22?6F
oU{m\r
private String sSiteURL; //Site's URL 2AU_<Hr6
private String sFilePath; //Saved File's Path zs7K :OlkA
private String sFileName; //Saved File's Name fpzC#
private int nSplitter; //Count of Splited Downloading File vu1F
(uRAK
{HQ?
public SiteInfoBean() NPKRX Li%
{//nSplitter的缺省值为5 U?H!:?,C
//default value of nSplitter is 5 _ea!psA0
this("","","",5); CB6<Vng}C
} k+%6:r,r&
e6]u5;B r
72Ft?;R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N0/DPZX7
{ ?mrG^TV^+r
sSiteURL= sURL; {6A3?q
sFilePath = sPath; &s\w: 9In
sFileName = sName; Lymy/9
this.nSplitter = nSpiltter; Ga$+x++'*
Xgc@cwd
qifX7AXHr
} -Vw,9VCF
,GGr@})
lS9rgq<n
public String getSSiteURL() P b2exS(
{ p]IF=~b
return sSiteURL; i!jxjP
} |WlWZ8]
^qYJx
!SEg4z
public void setSSiteURL(String value) Svy bP&i|
{ BEN=/ v
sSiteURL = value; hcwKi
} LbvnV~S
G'Jsk4:c
Al6)$8]e
public String getSFilePath() oJ>]=^?k
{ k)dLJ<EM
return sFilePath; OZs^c2 W
} t-i;
KR%DpQ&{'
@'s^
public void setSFilePath(String value) -AJe\ J 2
{ ^6oz3+
sFilePath = value; "{j4?3f)
} $#8dtF
0vt?yD
R/xeC [r
public String getSFileName() MAQkk%6[g
{ E"nIC,VZ
return sFileName; `(.K|l}
} PiP\T.XANa
y2yW91B,
OT&J OTk\
public void setSFileName(String value) hK&jo(V
{ 9v8{JaI3
sFileName = value; TE3A(N'
} -y)ij``VY
}RDGk+x7|
oxha8CF]D
public int getNSplitter() >7p?^*&7;
{ u-$(TyDEl|
return nSplitter; vzd1:'^t
} $&I##od
S{zi8Oc6
:4;ZO~eq!
public void setNSplitter(int nCount) F/IXqj
{ B{PI&a9~s%
nSplitter = nCount; M6[&od
} {'NdN+_C
} B#N(PvtE
I>B-[QEC
4U*J{''L
/* Om,+59ua*
**Utility.java !MOVv\@O
*/ hjtkq.@
package NetFox; #qtAFIm'
a4Qr\"Qm
]<V[H
public class Utility { ~DPjTR
yO;r]`j0
Az8>^|@
public Utility() NiQ`,Q$B
{ 6-c3v
}K!}6?17T
p'M5]G
} [#.E=s+&
m-dyvW+
//线程睡眠 AK]{^Hvz
public static void sleep(int nSecond) ) wtVFG
{ >7[. {Y
try{ ;Kob]b
Thread.sleep(nSecond); 01uMbtM
} Y?a*-"
catch(Exception e) ^1sX22k
{ lTBPq?4{
e.printStackTrace (); r({!ejT{U
} sKVN*8ia
} ]3uErnI
c=p`5sN)
//日志 a;WRTV
public static void log(String sMsg) $1y8gm
{ [*GIR0
System.err.println(sMsg); aVNBF`
} DK;p6_tT
D~E1hr&Vd>
a|Io)Qhr
public static void log(int sMsg) eKPxSN Z
{ z-$bce9*
System.err.println(sMsg); ~8L*N>Y
} osPJ%I`^
} KHV5V3q4
KCu@5`p
=NMT H[
/* kv{uf$X*ve
**TestMethod.java Y&!M#7/'J3
*/ ,7&`V=C
package NetFox; @*P$4c
%{WZ
^ ]02)cK
public class TestMethod { 1RpTI7
l?2(c
A{3Aw|;
public TestMethod() $<cio X
{ ///xx/weblogic60b2_win.exe G5a PjP
try{ {|nm0vg`A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |:BKexjHL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fr_esx
SiteFileFetch fileFetch = new SiteFileFetch(bean); &'4{/Gz
fileFetch.start(); ;T0F1
} $N4%I4
catch(Exception e){e.printStackTrace ();} Z]kk.@P
2[6>h)
ky>0
} cVya~ *
*y<Ru:D
__o`+^FS
public static void main(String[] args) ]wFKXZeK
{ ?@8[1$1a
new TestMethod(); |W4 \
} hqrI%%
} C%_^0#8-0
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