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)); =Mwuhk|*
} q:)PfP+
for(int i=0;i<nEndPos.length-1;i++) KZ[TW,Gw
{ |s/N?/qi
nEndPos = nStartPos[i+1]; Nkj$6(N=zJ
} U"8Hw@
nEndPos[nEndPos.length-1] = nFileLength; #2%V
} W|fE]RY
} h.#:7d(g
8Snv, Lb`^
A+Isk{d
//启动子线程 td%J.&K_*'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pd&KAu|<`
for(int i=0;i<nStartPos.length;i++) )-5eIy
{ )-[$m%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WZ6{9/%:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5`fUR/|[
nStartPos,nEndPos,i); zo@vuB.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vv,<#4d
fileSplitterFetch.start(); QAxy?m,'
} %XukiA+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }(u:K}8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PRiE2Di2S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kZ@UQ{>`
nEndPos = " + nFileLength); wg0_J<y]
// fileSplitterFetch[nPos.length-1].start(); PUO7Z2
S>T ;`,
+|dLR*s
//等待子线程结束 };rp25i
//int count = 0; _ s}aF
//是否结束while循环 In?+
boolean breakWhile = false; w=_^n]`R
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,^e2ma|z
while(!bStop) b(|&e
{ :F"IOPfU5[
write_nPos(); Conik`
Utility.sleep(500); =\2gnk~
breakWhile = true; am? k
tM\BO0
=PA?6Bm
for(int i=0;i<nStartPos.length;i++) t|oIzjKE/
{ !l#aq\:}~e
if(!fileSplitterFetch.bDownOver) i?pd|J
{ Dom]w.W5
breakWhile = false; ,\ 1X\
break; KNN{2thy `
} I$sXbM;z=
} hfIP
if(breakWhile) }xr0m+/
break; V Zbn@1
_XP}fx7$C
mYo~RXKGF
//count++; L9e<hRZ$
//if(count>4) 3HuocwWbz
// siteStop(); *ezMS
} ^#e|^]] L
[[T6X9
UmpHae
System.err.println("文件下载结束！"); \41/84BA
} .9ZK@xM&?
catch(Exception e){e.printStackTrace ();} 'vtJl
} c0e[vrP:
V0A>+
d<xi/
//获得文件长度 ;k@]"&t
public long getFileSize() ^bPpcm=
{ *A48shfO
int nFileLength = -1; o<lmU8xB=
try{ +UOVD:G
URL url = new URL(siteInfoBean.getSSiteURL()); 4Dzg r,V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P4yUm(@
httpConnection.setRequestProperty("User-Agent","NetFox"); Ms5qQ<0v_
]pB5cq7o
i75\<X
int responseCode=httpConnection.getResponseCode(); m.ka%h$
if(responseCode>=400) y,rdyt
{ |95K
processErrorCode(responseCode); F|+B8&-v
return -2; //-2 represent access is error a(yWIgD\\
} o8:9Yjs
r<(UN@T}
l v:GiA"X
String sHeader; 8q]"CFpa
!.#g
]vR Ol.
for(int i=1;;i++) ex~"M&^
{ }U>K>"AZl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }@ U}c6/
//Utility.log(in.readLine()); ;s$4/b/~
sHeader=httpConnection.getHeaderFieldKey(i); URj)]wp/
if(sHeader!=null) O251. hXK
{ 8MDivr/@
if(sHeader.equals("Content-Length")) on8$Kc
{ /oEDA^qx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F ]D^e{y
break; 73!NoDxb
} CTg79 ITYk
} l{3zlXk3z
else n?6^j8i
break; _?felxG[
} %LHt{:9.
} )R<93`q
catch(IOException e){e.printStackTrace ();} ,@p4HN*
catch(Exception e){e.printStackTrace ();} 7~1Fy{tc
CaED(0
R86i2',
Utility.log(nFileLength); nt&% sM-X
`%Kj+^|DS
5G2ueRVb
return nFileLength; qh}+b^Wi
} =v?V
YwH Fn+
$!p2Kf>/Q
//保存下载信息（文件指针位置） @JdeOL;
private void write_nPos() 3:$@DZT$
{ %kkDitmI{
try{ r&v!2A]:
output = new DataOutputStream(new FileOutputStream(tmpFile)); P^Og(F8;
output.writeInt(nStartPos.length); B/Q>i'e
for(int i=0;i<nStartPos.length;i++) e$QMR.'
{ =7kn1G.(
// output.writeLong(nPos); ~3Qa-s;g
output.writeLong(fileSplitterFetch.nStartPos); G]xN#O;
output.writeLong(fileSplitterFetch.nEndPos); qD"~5vtLqQ
} )Mflt0fp
output.close(); NODg_J~T
} 4\V/A+<W
catch(IOException e){e.printStackTrace ();} OiC|~8
catch(Exception e){e.printStackTrace ();} N1y,~Z
} I WT|dA >
Oel%lY}m3
P^q!Pye
//读取保存的下载信息（文件指针位置） 2Nm{.Y
private void read_nPos() P9`CW
{ c?c"|.-<p
try{ x)%"i)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *<{hLf
int nCount = input.readInt(); &Nr+-$
nStartPos = new long[nCount]; 1p/_U?H:|
nEndPos = new long[nCount]; d"3x11|
for(int i=0;i<nStartPos.length;i++) $*XTX?,'
{ S:g6z'e1
nStartPos = input.readLong(); L1k
nEndPos = input.readLong(); l%i*.b(
} -c0*
input.close(); xjxX4_
} Om7 '_}
catch(IOException e){e.printStackTrace ();} E\Iz:ES^
catch(Exception e){e.printStackTrace ();} 1"<{_&d1
} meap;p
pK>/c>de
~S :8M<aB
private void processErrorCode(int nErrorCode) g[ @Q iy
{ D7thLqA
System.err.println("Error Code : " + nErrorCode); ei]Q<vT6
} VJr~h "[
wB[ JFy"E
mH<|.7~0
//停止文件下载 Yu[MNX;G
public void siteStop() *ZRk)
{ 6khm@}}
bStop = true; W8]?dL}|
for(int i=0;i<nStartPos.length;i++) Qe9}%k6@E
fileSplitterFetch.splitterStop(); 7<8'7<X
j\BtaC
`X&d:!}F
} -@'RYY=
} %vG;'_gMB
//负责部分文件的抓取 YD~(l-?"
**FileSplitterFetch.java &d!ASa
*/ >N~jlr|
package NetFox; pZc`!f"
PCBV6Y7r
m60hTJ?N)
import java.io.*; ^6CPC@B1
import java.net.*; axXR-5c
`B3YP1
#H8QX5b)
public class FileSplitterFetch extends Thread { YAi@EvzCVy
9(a*0H
Q"LlBp>t|#
String sURL; //File URL _$}@hD*R~
long nStartPos; //File Snippet Start Position 0@&;JMh6<
long nEndPos; //File Snippet End Position ^d9o \
int nThreadID; //Thread's ID ^@'zQa
boolean bDownOver = false; //Downing is over 8-O:e
boolean bStop = false; //Stop identical *TxR2pC}
FileAccessI fileAccessI = null; //File Access interface 0J5$ Yw1'F
8l?@ o
PIsXX#`7;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4!M0)Nix
{ WUx2CK2N
this.sURL = sURL; yaI jXv
this.nStartPos = nStart; --`W1!jI@
this.nEndPos = nEnd; Sn;q:e3i{A
nThreadID = id; nu16L$]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P^BSl7cT
} 3[kl` *`
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#g Rns
public void run() rO,n~|YJ
{ 7B)@ aUj$
while(nStartPos < nEndPos && !bStop) d5W=?
{ $M4C4_oPy
fL&e^Q
<z wI@i
try{ 'HWPuWW
URL url = new URL(sURL); Ojp|/yd^YL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iA"H*0
httpConnection.setRequestProperty("User-Agent","NetFox"); Ei@al>.\
String sProperty = "bytes="+nStartPos+"-"; ef:Zi_o
httpConnection.setRequestProperty("RANGE",sProperty); !-B|x0fs
Utility.log(sProperty); }OgZZ8-_M
ab_EH}j1\q
vb\R~%@T,
InputStream input = httpConnection.getInputStream(); f(-3d*g
//logResponseHead(httpConnection); d\ Xijy
dpcv'cRfw
r?Pk}Q
byte[] b = new byte[1024]; $! UEpQ
int nRead; p1\EC#Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <2w41QZX
{ UzkX;UA
nStartPos += fileAccessI.write(b,0,nRead); l_&T)Ei
//if(nThreadID == 1) ?d)eri8,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YQ}IE[J}v
} c/G^}d%
0t00X/
?,!C0ts
Utility.log("Thread " + nThreadID + " is over!"); qd [Z\B
bDownOver = true; UO>S2u
//nPos = fileAccessI.write (b,0,nRead); `?(9Bl
} O~F8lQ
catch(Exception e){e.printStackTrace ();} %e=UYBj"
} l]P3oB}Yo
} *3y:Wv T>
f87lm*wZ
s|Zv>Qt
//打印回应的头信息 $Mqw)X&q
public void logResponseHead(HttpURLConnection con) ARid
{ kc"SUiy/
for(int i=1;;i++) [PU0!W;
{ !~f!O"n)3r
String header=con.getHeaderFieldKey(i); #_fL[j&
if(header!=null) ,09d"7`X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gG46hO-M%x
Utility.log(header+" : "+con.getHeaderField(header)); y/Q,[Uzk\
else +q~dS.
break; &qeMYYY
} ;c>IM]
} 4p/d>DTiM
4ko(bW#jL
Bf6\KI<V2
public void splitterStop() 'uF"O"*
{ Q-f?7*>
bStop = true; Gn?<~8a
} z_ia3k<
>z69r0)>
cpBTi
} !W45X}/o
oyo V1jO
Z|$OPMLX
/* }JBLzk5|
**FileAccess.java {o.i\"x;
*//文件访问(定位，写) +# tmsv]2
package NetFox; VH$hQPP5d
import java.io.*; M!b"c4|<
p3{ 3[fDx
Ba]^0Y u
public class FileAccessI implements Serializable{ vBjrI*0
wO ?A/s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,qO2D_
RandomAccessFile oSavedFile; RE75TqYW
long nPos; [>U =P`
NYp46;
3n=ftkI
public FileAccessI() throws IOException %u02KmV.
{ 5Qgh\4
this("",0); =LMM]'no,
} T0P_&E@X
f^kH[C
=GSe$f?
public FileAccessI(String sName,long nPos) throws IOException 5IiZnGu
{ d,caOE8N
oSavedFile = new RandomAccessFile(sName,"rw"); JQ]A"xTIa*
this.nPos = nPos; WkR=(dss8
oSavedFile.seek(nPos); )Fh5*UC
} \L{V|}"X
q<Zza
k'JfXrW<!
public synchronized int write(byte[] b,int nStart,int nLen) O;?Nz:/q
{ uu+)r
int n = -1; *k ^?L
try{ :f5"w+
oSavedFile.write(b,nStart,nLen); M[7$cfp-Y~
n = nLen; ,fW%Qv
} L4-v'Z;
catch(IOException e) t bEJyA
{ H|*Ual
e.printStackTrace (); rc+}KO
} &F#K=R| .j
xC+TO
i-*ZW:
return n; %?z8*G]M
} Ea\Khf]2
p;<brwN
@Lf-=9
} g<$q#l~4xH
TQg~I/
%#$K P
/* }MXC0Z~si
**SiteInfoBean.java MGE8S$Z
*/ QNesiV0MI
package NetFox; .-HwT3
- HiRXB
8Xjp5
public class SiteInfoBean { 2\J-7o=P
ErXzKf
u</LgOP`-
private String sSiteURL; //Site's URL <P1yA>=3`
private String sFilePath; //Saved File's Path :M _N
private String sFileName; //Saved File's Name G"|`&r@
private int nSplitter; //Count of Splited Downloading File %$CV?K$C
cHjnuL0fsy
qaZQ1<e
public SiteInfoBean() p]erk
{//nSplitter的缺省值为5 ] g]^^
//default value of nSplitter is 5 Vx*O^cM
this("","","",5); ].r~?9'/
} {IA3`y~
::R5F4
\qj(`0HG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !)$e+o^W
{ @\s*f7
sSiteURL= sURL; S5>?jn1
sFilePath = sPath; ATscP hk
sFileName = sName; c1aIZ
this.nSplitter = nSpiltter; [h[@?8vB
e> -fI_+b
h"$)[k~
} ptMDhMVW
e-Ma8+X\
iininITOS{
public String getSSiteURL() Hx#1TqC/
{ K|sk]2.
return sSiteURL; h1REL^!c
} OH/!Ky\@
6Mh"{N7
#Q'j^y7=z
public void setSSiteURL(String value) q)PLc{NO
{ ;nbV-<e
sSiteURL = value; wlsq[xP
} My<.^~
2D)B%nM[
'B yB1NL
public String getSFilePath() It:,8
{ 5u=>~yK+
return sFilePath; X([p0W 9V(
} :`>bh
{j[a'Gb
JBk >|q"
public void setSFilePath(String value) 7tQ?av
{ 8@A}.:
sFilePath = value; wU(!fw\
} b>]k=zd
^ DCBL&I
]@{l<ExP
public String getSFileName() 9oQ$w?=#$
{ PT39VI =
return sFileName; )0?u_Z]w9
} -]<<}@NF
Q4ZKgcC
@id!F<+%oD
public void setSFileName(String value) AjD?_DPc
{ ,s`4k?y
sFileName = value; 4@r76v}{
} G3dA`3
4t,f$zk
_qa9wK/
public int getNSplitter() A9Icn>3?`(
{ F[KM0t!
return nSplitter; *aW:Z6N
} V@o#" gZ
{5Sy=Y
D6,Ol4d
public void setNSplitter(int nCount) kX%vTl7F
{ g&I|@$\
nSplitter = nCount; ; ,n}>iTE
} _E2W%N
} {PKf]m
rT_J6F5J
rT(b t~Z
/* yb6gYN
**Utility.java XwIKpr8
*/ <f#pS[A
package NetFox; P,@/ap7J
~JHEr48
)F+wk"`+6
public class Utility { p|g7Z
G@P+M1c
0+T:};]
public Utility() mJZB@m u?
{ -QK-w>
xX.kKEo"d
]Z?jo#F
} .z[#j]k
y({lE3P
//线程睡眠 pi5DDK
public static void sleep(int nSecond) SZvp%hS0
{ ipyc(u6Z5
try{ L)c]i'WZ
Thread.sleep(nSecond); a66Ns7Rb
} (_]D\g~
catch(Exception e) W`uq,r0Xsy
{ ;FJFr*PM
e.printStackTrace (); [>KnMi=o)
} p z\8Bp}yo
} HCT+.n6
KAgxIz!^-1
//日志 |$g} &P8;
public static void log(String sMsg) *!pn6OJ"Q}
{ fp}5QUm-
System.err.println(sMsg); N}nE?|N=5
} o)n=n!A
0#CmB4!<O
WO6R04+WV
public static void log(int sMsg) qM<CBcON
{ m48Ab`
System.err.println(sMsg); {YG qa$+\
} p'A43
} \5}*;O@
_2hZGC%&E
@z^7*#vQv
/* ~G1B}c]
**TestMethod.java ~OWpk)Vq
*/ (8~D^N6Z
package NetFox; a"l\_D'.K8
yKy )%i
k"|Fu
public class TestMethod { .03Rp5+v
tUt_Q;%yC
p3>Md?e
public TestMethod() D#A6s32a
{ ///xx/weblogic60b2_win.exe TKQ^D
try{ Xzl$Qc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xck`"RU<xA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9h/Hy aN
SiteFileFetch fileFetch = new SiteFileFetch(bean); .>Qa3,v5
fileFetch.start(); 3m$ck$
} r'4Dj&9Ac
catch(Exception e){e.printStackTrace ();} Ww"]3
qeb}~FL"o
H>o \C
} [=",R&uD$
p[&b@U#
=WHI/|&
public static void main(String[] args) f[ KI T
{ q0DRT4K
new TestMethod(); [RY Rt/?Q
} J=&}$
} P| hwLM
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